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Tainan, Taiwan

National Cheng Kung University is a research-led comprehensive university in Tainan City, Taiwan. In Chinese, its name is shortened to 成大 . Cheng Kung is named after Cheng Ch'eng-Kung , who defeated the Dutch and founded the Kingdom of Tungning in Taiwan. NCKU is one of the most prestigious universities in Taiwan, with a high reputation in science, engineering, medicine, management, planning and design. According to US News and World Report - 2014 Global Universities Ranking , NCKU was ranked #22 Best Global University for Engineering and Computer Science. Times Higher Education- QS World University Rankings and Performance Ranking of Scientific Papers for World Universities, NCKU was ranked second or third among all universities in Taiwan. Many surveys throughout the years have shown that its students are most desired by Taiwanese companies. NCKU has 9 colleges, 40 departments, 82 graduate institutes, and 54 research centers, and it is also a major university, educational, and area-network center in Taiwan.NCKU is among the four universities of Taiwan's Public Ivy - the Taiwan Comprehensive University System. Wikipedia.


Kuo Y.-L.,National Cheng Kung University
Annals of Plastic Surgery | Year: 2015

BACKGROUND: De Quervain disease is a stenosing condition of the sheath of the abductor pollicis longus and extensor pollicis brevis tendons at the radial styloid process. Previous studies consistently reported that the pathological change of this condition is thought to be primarily an extensor retinaculum thickened by fibrosis and angiogenesis instead of inflammation. Contradictorily, the conservative treatment for de Quervain disease is anti-inflammatory medication. The inflammatory response may be involved in this disease; however, there is no present study directly evidencing whether the inflammatory responses exist in de Quervain disease or not. The histopathology of de Quervain disease is yet to be elucidated clearly.PURPOSE: To grade all specimens in the different stages and characterize specific inflammatory cell and factors to examine whether inflammatory response is involved in de Quervain disease.METHODS: Retinaculum samples were collected from 13 patients with de Quervain disease after surgery. The specimens were evaluated histologically by collagen structure grading and immunohistochemically by quantifying the presence of neutrophil elastase, macrophages, cyclooxygenase, and vascular endothelium.RESULTS: Neutrophil elastase and cyclooxygenase occur in the de Quervain disease retinaculum and increased with the grade of collagen structure. After angiogenesis, macrophage infiltration occurs in the grade II matrix worse than grade III matrix.CONCLUSIONS: Inflammation is present in de Quervain disease. This study provides direct evidence for inflammatory cell and infiltration factors and offer valuable clues for specific pharmacological therapies for de Quervain disease. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. Source


Wen C.-D.,National Cheng Kung University
Journal of Materials Engineering and Performance | Year: 2011

Experiments were first conducted to measure the emissivity values of a variety of steel samples at 700, 800, and 900 K. The effects of wavelength, temperature, alloy composition, and heating time on emissivity were investigated. Multispectral radiation thermometry (MRT) with linear emissivity models (LEMs) and log-linear emissivity models (LLEs) were then applied to predict surface temperature. Parametric influences of the number of wavelengths and order of emissivity models were examined. Results show that the spectral emissivity decreases with increasing wavelength and increases with increasing temperature. Steel with higher chromium content has lower emissivity value because of the chromium oxide protection layer. The spectral emissivity reaches steady state after the third hour heating due to the surface oxidation becoming fully developed. Increasing the order of polynomial and increasing the number of wavelengths cannot improve temperature measurement accuracy. Overall, the first-order LEM and the first-order LLE showed the best accuracy for different alloys, the number of wavelengths, and temperatures. © 2010 ASM International. Source


Tullos D.,16 Gilmore Hall | Wang H.-W.,National Cheng Kung University
Earth Surface Processes and Landforms | Year: 2014

The rates and styles of channel adjustments following an abrupt and voluminous sediment pulse are investigated in the context of site and valley characteristics and time-varying sediment transport regimes. Approximately 10.5 x 106m3 of stored gravel and sand was exposed when Barlin Dam failed during Typhoon WeiPa in 2007. The dam was located on the Dahan River, Taiwan, a system characterized by steep river gradients, typhoon- and monsoon-driven hydrology, high, episodic sediment supply, and highly variable hydraulic conditions. Topography, bulk sediment samples, aerial photos, and simulated hydraulic conditions are analyzed to investigate temporal and spatial patterns in morphology and likely sediment transport regimes. Results document the rapid response of the reservoir and downstream channel, which occurred primarily through incision and adjustment of channel gradient. Hydraulic simulations illustrate how the dominant sediment transport regime likely varies between study periods with sediment yield and caliber and with the frequency and duration of high flows. Collectively, results indicate that information on variability in sediment transport regime, valley configuration, and distance from the dam is needed to explain the rate and pattern of morphological changes across study periods. © 2013 John Wiley & Sons, Ltd. Source


Young W.-B.,National Cheng Kung University
IEEE Transactions on Components, Packaging and Manufacturing Technology | Year: 2011

In the flip-chip packaging, an underfill encapsulant is used to fill the gap between the chip and the substrate around the solder bumps. The underfill can reduce the thermal stress in solder bumps but increase the stress in the silicon. Epoxy with silica fillers is usually used as the underfill materials. These materials exhibit the non-Newtonian effect during the underfill flow and this type of effect needs to be included in the simulation of the underfilling process. In the analysis, the underfill flow can be treated as a flow through a porous medium. This paper provides the formulation of the effective permeability in the porous flow domain of the flip-chip encapsulation for a non-Newtonian fluid. An average viscosity of the encapsulant is also proposed for the flow in the porous flow domain. It is found the non-Newtonian flow will affect the filling time largely while the filling pattern is similar. The non-Newtonian flow model must be employed in order to accurately predict the underfilling flow. © 2011-2012 IEEE. Source


Hsieh J.-C.,National Cheng Kung University | Lin J.-L.,Chang Jung Christian University
IEEE Transactions on Industrial Electronics | Year: 2011

A novel self-oscillating electronic ballast with dimming capability and high power factor correction (PFC) is proposed in this paper. The single-stage electronic ballast integrates a buck-boost PFC stage with a half-bridge LCC series-parallel resonant inverter. The buck-boost semistage operating in discontinuous conduction mode inherently has high PFC. The inverter is dimmable in self-oscillation mode, which is achieved using pulsewidth modulation and variable-frequency controls. The dimming circuit is simple and low cost. The self-sustained oscillation of the dimmable electronic ballast for fluorescent lamps was verified using the dual-input describing function method. A prototype of a 10-W dimmable electronic ballast was implemented to verify the theoretical analysis. © 2006 IEEE. Source


Chin W.-L.,National Cheng Kung University
IEEE Transactions on Vehicular Technology | Year: 2011

Orthogonal frequency-division multiplexing (OFDM) is a promising technology for communication systems. However, the synchronization of OFDM over dispersive fading channels remains an important and challenging issue. In this paper, a synchronization algorithm for determining the symbol timing offset and the carrier frequency offset (CFO) in OFDM systems, based on the maximum-likelihood (ML) criterion, is described. The new ML approach considers time-dispersive fading channels and employs distinctive correlation characteristics of the cyclic prefix at each sampling time. The proposed symbol timing estimation is found to be a 2-D function of the symbol timing offset and channel length. When compared with previous ML approaches, the proposed likelihood function is optimized at each sampling time without requiring additional pilot symbols. To practically realize the proposed method, a suboptimum approach to the ML estimation is adopted, and an approximate but closed-form solution is presented. Nonlinear operations of the approximate solution can be implemented using a conventional lookup table to reduce the computational complexity. The proposed CFO estimation is also found to depend on the channel length. Unlike conventional schemes, the proposed method fully utilizes the delay spread of dispersive fading channels (which usually reduces the accuracy of estimations). Furthermore, the CramérRao lower bound (CRLB) on the CFO estimate is analyzed, and simulations confirm the advantages of the proposed estimator. © 2006 IEEE. Source


Wong T.-T.,National Cheng Kung University
Computational Statistics and Data Analysis | Year: 2010

Generalized Dirichlet distributions have a more flexible covariance structure than Dirichlet distributions, and the computation for the moments of a generalized Dirichlet distribution is still tractable. For situations under which Dirichlet distributions are inappropriate for data analysis, generalized Dirichlet distributions will generally be an applicable alternative. When the expected values and the covariance matrix of random variables can be estimated from available data, this study introduces ways to estimate the parameters of a generalized Dirichlet distribution for analyzing compositional data. Under the assumption that the sample mean of every variable must be considered for parameter estimation, we present methods for choosing the statistics from a sample covariance matrix to construct a generalized Dirichlet distribution. Some rules for removing inappropriate statistics from a sample covariance matrix to speed up the estimation process are also established. An example for Taiwan's car market is introduced to demonstrate the applicability of the parameter estimation methods. © 2010 Elsevier B.V. All rights reserved. Source


Ju S.H.,National Cheng Kung University
CMES - Computer Modeling in Engineering and Sciences | Year: 2010

This study develops an OpenMP scheme to parallel the preconditioned conjugate gradient methods (PCG) in shared memory computers. The proposed method is simple and systematic, so a minor change in traditional PCG methods may produce effective parallelism. At first, the global stiffness matrix is renumbered in order to produce a parallel three-line form matrix, and a subroutine only needs to be called once in the finite element analysis. Several basic OpenMP commands are then added into the traditional incomplete Cholesky factorization (ILU) and symmetric successive over-relaxation (SSOR) codes to make the procedures of matrix multiplication, decomposition, forward substitution, and backward substitution fully parallel. © 2010 Tech Science Press. Source


Chen Y.H.,National Cheng Kung University
Journal of Alloys and Compounds | Year: 2013

This study investigated the high-temperature properties of nano-goethite, nano-magnetite, and nano-maghemite. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) of these nano-minerals revealed that phase-transition temperatures increased with increasing particle sizes. This was due to the high surface energy of the nano-minerals with small particle sizes, which caused them to require lower energies to change their structures, and thereby, resulted in lower phase-transition temperatures. Further, the transition temperatures measured by ex situ and in situ high-temperature X-ray diffraction (XRD) were lower than those observed by TGA-DTA. This may be due to the difference in the atmosphere and heating time in the high-temperature processes. In this study, we found that the particle size of nano-minerals, atmosphere (oxygen pressure), and heating time were the key factors influencing the transition temperature, phase, and path. TGA-DTA measurements gave the initial clue to understand the phase transition, and in situ high-temperature XRD measurements helped elucidate the exact phase-transition behavior of the nano-minerals. © 2012 Elsevier B.V. All rights reserved. Source


Hsu H.-C.,National Cheng Kung University
Nonlinear Analysis: Real World Applications | Year: 2013

Within the Lagrangian reference frame we present a third-order solution for water particles in a two-dimensional wave and shear current interaction flow. For the case of linear shear current, parametric solutions of particle trajectory are obtained in the Lagrangian coordinates. In particular, the Lagrangian wave frequency and the Lagrangian mean level of particle motion can be obtained which are different from those in an Eulerian description. For the case of negative vorticity, when compared with the pure wave case, particle trajectory traveling in the positive x-direction is found to be larger, and faster, while the opposite is true when traveling in the negative x direction. Moreover, the influence of a negative vorticity is found to increase the relative horizontal distance traveled by a water particle, while the converse is true in the case of a positive vorticity. © 2013 Elsevier Ltd. All rights reserved. Source


Young W.-B.,National Cheng Kung University
Composites Part A: Applied Science and Manufacturing | Year: 2013

Advanced grid stiffened (AGS) structures are made of carbon fiber reinforced polymer composites, which consists of a main panel with isogrid stiffeners. During the co-curing process, the autoclave pressure will compress the surface of the AGS structure to repel excess resin and voids. Because of the thermal expansion of the rubber, the rubber mold can provide the necessary lateral compacting forces on the rib stiffeners. This study constructs a three dimensional numerical model to simulate the consolidation behavior between the skin prepreg and the silicone rubber under a preset temperature profile. The model could provide the thickness distribution and fiber volume fraction of the AGS after the co-curing process. The consolidation pressure of the silicone rubber is proportional to its CTE and the curing temperature. With the numerical model, a suitable type of silicone rubber can be selected for the tooling. © 2012 Elsevier B.V. All rights reserved. Source


Chen W.-H.,National Cheng Kung University | Peng J.,University of British Columbia | Bi X.T.,University of British Columbia
Renewable and Sustainable Energy Reviews | Year: 2015

Torrefaction is a mild pyrolysis, which has been explored for the pretreatment of biomass to increase the heating value and hydrophobicity. Due to its potential applications for making torrefied pellets, which can be used as a high quality feedstock in gasification for high quality syngas production and as a substitute for coal in thermal power plants and metallurgical processes, torrefaction and densification have attracted great interest in recent years from both academia and bioenergy industry. This paper provides a comprehensive review of research progresses in this area, drawing on major contributions from two major research groups of the authors on torrefaction and densification at Canada and Taiwan as well as literatures. It is revealed that torrefaction of various biomass species and their major components, lignin, cellulose and hemicelluloses have been extensively studied in thermogravimetric apparatus (TGA) under both inert (N2) and oxidative (O2, H2O) environments to elucidate the weight loss as a function of temperature, particle size and time. It was found that the higher heating value and saturated water uptake of torrefied biomass were a strong function of weight loss, which represents the degree of torrefaction. When torrefied sawdust is compressed into torrefied pellets, more mechanical energy is consumed and higher die temperature is required to make torrefied pellets of similar density and hardness as regular pellets. Simple economics analyses based on laboratory scale experimental data showed that because of the potential savings from pellets transport, handling and storage logistics, the overall cost for torrefied pellets can be lower than regular pellets in European market for both European and Canadian pellets. The gasification could be improved in terms of both energy efficiency and syngas quality because of the removal of oxygenated volatile compounds from torrefied biomass. © 2015 Elsevier Ltd. All rights reserved. Source


Lai C.C.,National Cheng Kung University
Journal of pediatric ophthalmology and strabismus | Year: 2011

The authors describe an 11-year-old boy developing bilateral acute anterior uveitis, papillitis in one eye, and neuroretinitis in the other eye after an upper respiratory tract infection of influenza A virus, possibly H1N1. Steroid pulse therapy resolved these conditions. The authors recommend alertness for visual blurring and ocular inflammation after influenza A infection. Copyright 2011, SLACK Incorporated. Source


Cheng Y.-H.,National Cheng Kung University
Transportation Research Part C: Emerging Technologies | Year: 2011

More and more public transport system passengers plan their trips by using website services. The passengers' perceived service quality of a website plays a crucial role in recognizing the satisfaction of a transportation service chain. This study aims to investigate the passengers' perception of electronic service quality (e-SQ) delivery through the Taiwan High Speed Rail's (THSR) website, by adopting the Rasch measurement model to measure a subjective latent construct: perceived e-SQ. The Rasch model can compare person parameters with item parameters, which are then subjected to a logarithmic transformation along a logit scale to clearly identify which e-SQ measurement items are appreciated by certain passengers. Analytical results show substantial differences between the perceived e-SQ of various personal characteristics such as age, income, and trip types. Empirical results also demonstrate that passengers are most satisfied with the website's accuracy of information and introduction to the THSR stations' surrounding area, but are not satisfied with instructions when a transaction fails as well as the carriage layout of the THSR. Our analytical results also identify which service items lead to the perceived e-SQ difference between business trip and leisure trip passengers. The relationship between the two main attribute dimensions - quality of transportation information provided and quality of website services - are also further examined. The empirical results can help a transportation system service operator to better understand how passengers perceive e-SQ and to suggest what should be improved. © 2011 Elsevier Ltd. Source


Chou Y.-C.,University of California at Los Angeles | Lu K.-C.,National Cheng Kung University | Tu K.N.,University of California at Los Angeles
Materials Science and Engineering R: Reports | Year: 2010

Transition-metal silicides have been used in the salicide process to form gate and source/drain contacts in MOSFET devices. How to control silicide formation in shallow junction devices and the kinetics of single silicide phase formation between the Si and metal thin films have received extensive attention and study. As the trend of miniaturization of Si devices moves from 45 nm to smaller sizes, the formation of nanoscale metal silicides has attracted renewed interest in silicide formation. Nanostructures in Si nanowires have been studied for basic components in electronic and optoelectronics devices, especially for biosensors. Well-defined nanoscale building blocks such as ohmic contacts and gates on Si nanowires must be developed in order to be assembled into functional circuit components in future nanotechnology. It requires a systematic study of solid-state chemical reactions in the nanoscale to form these circuit components. In this review, we compare silicide formation in thin films and in nanowires and focus on the nucleation and growth of epitaxial silicides. The difference of silicide formation between the thin film case and the nanowire case, especially the kinetics of nucleation and growth, will be emphasized. Source


Young W.-B.,National Cheng Kung University
Microelectronics Reliability | Year: 2010

The viscosity of the underfill encapsulant may be different under the conditions of different shear rate, filler content, and temperature. Most of the encapsulant is epoxy containing silica fillers. It exhibits non-Newtonian behavior in the underfill flow. The effect of the viscosity variations on the underfill filling flow was investigated in this study. An analytical model of the filling flow is proposed to accomplish the shear-rate depending viscosity. Due to the addition of fillers in the encapsulant, the viscosity may exhibit both shear thinning and thickening behaviors depending on the temperature and filler content. This study proposes a model of the viscosity considering both effects. In the situations demonstrated in the results, the shear thinning and thickening effects may have major influence on the velocity profile and the filling speed. © 2010 Elsevier Ltd. All rights reserved. Source


Mohanty U.S.,National Cheng Kung University
Journal of Applied Electrochemistry | Year: 2011

The synthesis of various nanoscale materials, such as nanoparticles, nanowires of Au, Pt, Ni Co, Fe, Ag etc., by electrodeposition techniques have been demonstrated in this article. Both potentiostatic and galvanostatic methods were employed to carry out the electrodeposition process under different potential ranges, time durations, and current densities. The electrochemical behavior of the deposited nanoparticles on various substrates was investigated by cyclic voltammetric and chronoamperometric techniques. The synthesis of mono-dispersed gold (Au) nanoparticles on indium tin oxide (ITO) coated glass, preparation of Au nanorods on nanoporous anodic alumina oxide (AAO), formation of Au nanoclusters on polypyrrole-modified glassy carbon electrode and one-step electrodeposition of nickel nanoparticle chains embedded in TiO2 etc. have been highlighted in this article. The potential applications of synthesized nanoparticles such as the role of maghemite (Fe2O 3) in arsenic remediation, higher electrocatalytic activity of Ag nanoclusters for the reduction of benzyl chloride, and the role of C 60 nanoparticle-doped carbon film in fabrication processes are also presented in this article. © 2010 Springer Science+Business Media B.V. Source


Peng M.,Beijing University of Posts and Telecommunications | Liang D.,Beijing University of Posts and Telecommunications | Wei Y.,Beijing University of Posts and Telecommunications | Li J.,Beijing University of Posts and Telecommunications | Chen H.-H.,National Cheng Kung University
IEEE Communications Magazine | Year: 2013

Self-organizing network, or SON, technology, which is able to minimize human intervention in networking processes, was proposed to reduce the operational costs for service providers in future wireless systems. As a cost-effective means to significantly enhance capacity, heterogeneous deployment has been defined in the 3GPP LTEAdvanced standard, where performance gains can be achieved through increasing node density with low-power nodes, such as pico, femto, and relay nodes. The SON has great potential for application in future LTE-Advanced heterogeneous networks, also called HetNets. In this article, state-of-the-art research on self-configuring and self-optimizing HetNets are surveyed, and their corresponding SON architectures are introduced. In particular, we discuss the issues of automatic physical cell identifier assignment and radio resource configuration in HetNets based on selfconfiguring SONs. As for self-optimizing SONs, we address the issues of optimization strategies and algorithms for mobility management and energy saving in HetNets. At the end of the article, we show a testbed designed for evaluating SON technology, with which the performance gain of SON algorithms is demonstrated. © 2013 IEEE. Source


Kao C.,National Cheng Kung University | Liu S.-T.,VaNung University
Fuzzy Sets and Systems | Year: 2011

Two-stage DEA (data envelopment analysis) models show the performance of individual processes, and thus are more informative than the conventional one-stage models for making decisions. This paper extends this approach from deterministic to uncertain situations, where the observations are represented by fuzzy numbers. The extension principle is utilized to develop a pair of two-level mathematical programs to calculate the lower and upper bounds of the α-cut of the fuzzy efficiency. By enumerating various values of α, the membership functions of fuzzy efficiencies are constructed numerically. It is found that the property of the system efficiency being equal to the product of the two process efficiencies, which holds for the deterministic case, also holds for the fuzzy case. This property can be generalized to series systems with more than two processes. An example of non-life insurance companies in Taiwan is used to explain how to calculate the system and process efficiencies and how to derive their relationship when the data is fuzzy. © 2011 Elsevier B.V. Source


Liu Y.-C.,National Cheng Kung University
Journal of the Franklin Institute | Year: 2015

This paper proposes a system framework and control algorithms that enable a human operator to simultaneously interact with a group of swarm robot in a remote environment. In order to cope with kinematic dissimilarity and spatial discrepancy between human and swarm systems, a task-oriented control framework is developed. Based on the proposed control system, the human operator is able to convey action commands to the swarm, and the swarm robot can provide feedback information for the human operator. Additionally, the cognitive limitation of the human operator due to lack of entire information about the remote environment can be mitigated by utilizing the null-space of the swarm robot. Stability and performance of the proposed control system are investigated when the communication channels are subject to time delays and the system is influenced by non-passive external forces. The control algorithms are validated via numerical simulations on a 3-DOF robotic manipulator with a group of mobile swarm robot. © 2014 The Franklin Institute. Source


Chang M.-X.,National Cheng Kung University
IEEE Transactions on Signal Processing | Year: 2011

For a real band-limited periodic signal, there are reconstruction formulas that realize the ideal discrete-to-continuous (D/C) conversion within one period of the signal. However, the previous results may not be suitable for general complex band-limited periodic signals. For complex band-limited periodic signals, in this paper we first propose the reconstruction formulas, which lead to realizable forms of ideal D/C conversion. We then derive the correlation function of the interpolation pulse, and this helps us construct a matched filter that can implement the exact sampling (C/D conversion) of a complex band-limited periodic signal. When there exists noise in the sampling process, comparing with the ideal impulse sampling, the proposed C/D conversion can maintain finite output noise variance. The correlation function of the output noise is also given, and the oversampling effect of noise is analyzed. For a complex interpolation pulse, in general we cannot decouple the ideal D/C (or C/D) conversion into two independent D/C (or C/D) conversions for the real and imaginary parts of the signal. We also give the extended forms and decomposition forms of the proposed D/C and C/D conversions. Our results are applied to derive the ideal D/C and C/D conversions in the precoded orthogonal frequency-division multiplexing (POFDM) system. The resulted interpolation pulses are used to characterize the single-carrier (SC) block transmission under the POFDM architecture. We give characteristics that distinguish the SC block transmission from traditional SC transmission. © 2010 IEEE. Source


Dexamethasone (DEX), a synthetic glucocorticoid, is commonly used to prevent or lessen the morbidity of chronic lung disease in preterm infants. However, evidence is now increasing that this clinical practice negatively affects somatic growth and may result in long-lasting neurodevelopmental deficits. We therefore hypothesized that supporting normal somatic growth may overcome the lasting adverse effects of neonatal DEX treatment on hippocampal function. To test this hypothesis, we developed a rat model using a schedule of tapering doses of DEX similar to that used in premature infants and examined whether the lasting influence of neonatal DEX treatment on hippocampal synaptic plasticity and memory performance are correlated with the deficits in somatic growth. We confirmed that neonatal DEX treatment switched the direction of synaptic plasticity in hippocampal CA1 region, favoring low-frequency stimulation- and group I metabotropic glutamate receptor agonist (S)-3,5,-dihydroxyphenylglycine-induced long-term depression (LTD), and opposing the induction of long-term potentiation (LTP) by high-frequency stimulation in the adolescent period. The effects of DEX on LTP and LTD were correlated with an increase in the autophosphorylation of Ca(2+)/calmodulin-dependent protein kinase II at threonine-286 and a decrease in the protein phosphatase 1 expression. Neonatal DEX treatment resulted in a disruption of memory retention subjected to object recognition task and passive avoidance learning. The adverse effects of neonatal DEX treatment on hippocampal synaptic plasticity and memory performance of the animals from litters culled to 4 pups were significantly less than those for the 8-pup litters. However, there was no significant difference in maternal care between groups. Our results demonstrate that growth retardation plays a crucial role in DEX-induced long-lasting influence of hippocampal function. Our findings suggest that therapeutic strategies designed to support normal development and somatic growth may exert beneficial effects to reduce lasting adverse effects following neonatal DEX treatment. Source


Lin C.-C.,National Chiao Tung University | Yang C.-H.,National Cheng Kung University | Shyua J.Z.,National Chiao Tung University
Energy Policy | Year: 2013

Utilities are increasing their investment in smart grid technologies because of the rising demand for electricity, the aging transmission and distribution infrastructure in developed countries and the need for real-time visibility of energy supply and demand to optimize service reliability and cost. Government policies are contributing to this rising investment in the smart grid in many countries around the globe. Using Rothwell and Zegveld's innovation policy framework as a starting point, this paper compares innovation policy in smart grids across the Pacific; specifically, China and the USA. This research describes the policy tools used by both countries and presents results that indicate national preferences for innovation policy that differ in the ways in which they are linked with the state of the power system. China has preferred to use "supply-side policy," which focuses on "public enterprise, scientific and technical development and legal regulation." The USA has preferred to use "environmental-side policy," which focuses on "scientific and technical development, financial, political and public enterprise." This paper also describes in detail a number of innovation policies being pursued in the smart grid industry in both China and the USA. © 2013 Elsevier Ltd. Source


Hwu C.,National Cheng Kung University
International Journal of Solids and Structures | Year: 2010

Since Stroh-like formalism for coupled stretching-bending analysis preserves essential features of Stroh formalism for two-dimensional anisotropic elasticity, it becomes important to get the corresponding explicit expressions of some important matrices frequently appeared in Stroh-like formalism. In this paper, explicit expressions are obtained for the fundamental elasticity matrix N, the generalized fundamental elasticity matrix N (θ), the material eigenvector matrices A and B and Barnett-Lothe tensors L, S and H. In these expressions N, A and B are presented for the general laminates, whereas the other matrices are presented only for the symmetric laminates. To show the applicability to the degenerate laminates, these expressions are further reduced to the isotropic plates. Finally, they are applied to get the explicit real component form solutions of the Green's functions for an infinite isotropic plate. © 2009 Elsevier Ltd. All rights reserved. Source


Shen S.C.,National Cheng Kung University
Microelectronic Engineering | Year: 2010

Inhalation therapy is being applied in the home care field to a gradually increasing degree, and therefore two issues of great importance are the convenience and portability of medical devices. Hence, this paper presents a novel cymbal-shaped high power microactuator (CHPM) that includes a ring-type piezoelectric ceramics and a cymbal-shaped micro nozzle plate. The latter can focus energy on the center of the nozzle plate and induce a large force, which provides the cymbal-shaped microactuator with high power to spray medical solutions of high-viscosity produce ultra-fine droplets and increase the atomization rate. In this research, the CHPM can reduce liquids to droplets of an ultra-fine size distribution (Mass Median Aerodynamic Diameter, MMAD), increasing the nebulizing rate and enabling the spraying of high-viscosity fluids (lavender oil, cP > 3.5). The ultra-fine droplets were of a MMAD of less than 4.07 μm at 127.89 kHz and the atomization rate was 0.5 mL/min. The drive voltage of CHPM was only 3 V, and the power consumption only one-tenth that of ultrasonic atomizers at 1.2 W. The simulation and experiments carried out in this study proved that the droplets are much smaller than those produced by current conventional devices. Therefore, the CHPM is suitable for use in the development of a convenient and portable inhalation therapy device. © 2009 Elsevier B.V. All rights reserved. Source


Wu J.-H.,National Cheng Kung University | Huang Y.-H.,Industrial Technology Research Institute of Taiwan
Applied Energy | Year: 2014

Traditional electricity planning models pursue minimal costs, yet their design often results in an underestimation of the true benefits of renewable energy. This paper attempts to introduce different complementary approaches to traditional electricity planning model to incorporate various renewable energy characteristics and uses Taiwan's electricity sector as a case study. The portfolio theory, learning curve theory and the capacity credit are applied in the proposed model to reflect characteristics of renewable energy, such as a hedge against fossil fuel price volatility, significant technological progress, and intermittent generation. Simulation results demonstrate that using renewable energies has the advantage of hedging against the volatile fossil fuel price risk as well as reducing carbon dioxide emissions. Considering the intermittency of renewable energies requires LNG-fired plants to serve as the backup generators. However, wind power can only account for limited share of total installed capacity due to the limited land resources in Taiwan. Therefore, taking intermittency into account only demonstrates a small influence of the reserve margins of the entire power system and the total generation costs. © 2014 Elsevier Ltd. Source


Hsu H.-C.,Kings College London | Hsu H.-C.,National Cheng Kung University
Nonlinear Analysis: Real World Applications | Year: 2014

We present an exact solution of the nonlinear governing equations for geophysical water waves in the β-plane approximation near the equator. © 2014 Elsevier Ltd. All rights reserved. Source


Chu C.-S.,Ming Chi University of Technology | Lo Y.-L.,National Cheng Kung University
Sensors and Actuators, B: Chemical | Year: 2010

This paper presents a highly sensitive dissolved oxygen sensor comprising an optical fiber coated at one end with core-shell silica nanoparticles and platinum(II) meso-tetrakis (pentafluorophenyl) porphyrin (PtTFPP) embedded in an n-octyltriethoxysilane (Octyl-triEOS)/tetraethylorthosilane (TEOS) composite xerogel. The sensitivity of optical fiber dissolved oxygen sensor is quantified in terms of the ratio I0/I100, where I0 and I100 represent the detected fluorescence intensities in fully deoxygenated and fully oxygenated water, respectively. The experimental results show that the optical fiber dissolved oxygen sensor has a sensitivity of approximately 117 in the range 0-40 mg/L of dissolved oxygen concentrations. The experimental results show that as compared to the other optical dissolved oxygen sensors based on Pt(II) or Ru(II) complexes, the proposed optical fiber dissolved oxygen sensor has the highest sensitivity. In addition to the increased surface area per unit mass in the sensing surface, the dye entrapped in the core of silica nanoparticles also play an important role in the increased sensitivity because of the penetration of substantial amount oxygen molecules through the porous silica shell. © 2010 Elsevier B.V. All rights reserved. Source


Huang Y.-H.,Chung Yuan Christian University | Wu J.-H.,National Cheng Kung University
Energy Policy | Year: 2011

Due to Taiwan's lack of natural resources, dependence on imported energy, and pursuit of sustainable development, renewable energies are extremely important for Taiwan's future energy supply. Since Taiwan's feed-in tariff (FIT) is still in its initial stage, one must examine whether the current system is compatible with a well-designed FIT scheme. This study examines the main features of Taiwan's FIT system and assesses design options using several criteria. Additionally, one of the most important elements of a FIT scheme, namely, a tariff system, is discussed. Taiwan's FIT scheme has the design options required by well-functioning FITs, and the guaranteed-return tariff system coincides with the spirit underlying leading global FITs; however, many issues, such as setting goals by stages, refinement of the tariff calculation methodology, and elimination of other non-economic barriers, must be addressed to achieve future developmental goals and green industry growth. © 2011 Elsevier Ltd. Source


Chen C.-H.,National Cheng Kung University | Chen C.-H.,National Center for Theoretical science | Cvetic G.,University of Santa Maria in Ecuador | Kim C.S.,Yonsei University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2011

The updated CDF measurement of the forward-backward asymmetry AFB in the top quark production pp-→tt- at Tevatron (with s=1.96 TeV) shows a deviation of 2 σ from the value predicted by the Standard QCD Model. We present calculation of this quantity in the scenario, where colored unparticle physics contributes to the s-channel of the process, and obtain the regions in the plane of the unparticle parameters λ and dU, which give the values of the AFB and of the total tt- production cross section compatible with the present measurements. © 2010 Elsevier B.V. Source


Chang W.-J.,National Cheng Kung University
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2016

The current practice of evaluating the liquefaction resistance of gravelly soils with shear-wave velocity relies on the assumption that liquefiable gravelly soils behave as sandy ones. Recent laboratory tests on gap-graded gravelly sands show that the cyclic resistance is dominated by the packing conditions of the sand matrix, while the shear-wave velocity is affected by the gravel content. Taking these findings into account, the gravel content-corrected shear-wave velocity is derived based on the time-average equation of lumped gravel particles and the sand matrix. Based on analyses of case histories, a three-step procedure, which includes screening of gravelly sands, computation of stress-normalized, gravel content-corrected shear-wave velocity, and cyclic resistance evaluation using the modified correlation between the corrected shear wave velocity and the cyclic resistance, is proposed for evaluating the cyclic resistance ratio of gravelly sands. Comparisons with case histories show that the proposed procedure can significantly improve the estimation of cyclic resistance. © 2016 American Society of Civil Engineers. Source


Tumor suppressor gene (TSG) RASSF1A and candidate TSG BLU are two tandem head-to-tail genes located at 3p21.3. We hypothesized that there may be a concordance on their gene expression and promoter methylation status. If not, then there may be an insulator located between RASSF1A and BLU genes that provides a barrier activity. We first identified potential transcriptionally important CpG sites using the methylation-specific oligonucleotide array in relation to mRNA expression of RASSF1A and BLU genes in primary lung tumors. We demonstrated that E2F1 bound to the potential transcriptionally important CpG sites in RASSF1A gene of a normal lung cell line expressing RASSF1A transcripts, whereas loss of E2F1 binding to RASSF1A in A549 cancer cell line was the result of DNA methylation. Both RASSF1A and BLU genes had their own potential transcriptionally important CpG regions. However, there was no correlation of methylation status between RASSF1A and BLU. Using gel shift assay and chromatin immunoprecipitation-PCR (ChIP-PCR), we found that CCCTC-binding factor (CTCF) bound to insulator sequences located between these two genes. Bisulfite sequencing and ChIP-PCR revealed distinct methylation and chromatin boundaries separated by the CTCF binding domains in normal cells, whereas such distinct epigenetic domains were not observed in cancer cells. Note that demethylation reagent and histone deacetylase inhibitor treatments led to CTCF binding and recovery of barrier effect for RASSF1A and BLU genes in cancer cells. Our study dissects the potential transcriptionally important CpG sites for RASSF1A and BLU genes at the sequence level and demonstrates that CTCF binding to the insulator of BLU gene provides a barrier activity within separate epigenetic domains of the juxtaposed BLU and RASSF1A loci in the 3p21.3 gene cluster region. Source


Huang C.-C.,National Cheng Kung University
Geosynthetics International | Year: 2011

Performance-based designs for footings placed on reinforced ground that take their ductile behaviour into account require better knowledge of the settlement of footings subjected to peak footing loads. The validity of theoretical formulae for ultimate bearing capacity and settlement for footings on reinforced level ground, proposed previously by the author, are examined, based on recent experimental evidence. It was found that the formula for the ultimate bearing capacity increase in reinforced level sandy ground, based on the deep-footing and wide-slab mechanisms proposed by the author, works well in evaluating ultimate bearing capacity ratios for footings placed on level ground reinforced with high-tensile-stiffness reinforcement. The upper and lower bounds for footing settlements under peak footing loads were derived based on 42 loading test results. They were then applied to three additional series of loading tests using various types of reinforcing material, such as a relatively extensible polymeric mesh and three-dimensional geocell layers with a deep embedment. There was good agreement between the theoretical and measured values of ultimate footing settlement ratios for reinforced ground reinforced with a high-tensilestiffness geogrid. It was indicated that using three-dimensional geocell reinforcement with a deep embedment may generate greater footing settlements than those predicted by the upper-bound equation proposed here. It was also indicated that using high-tensile-stiffness geogrids in reinforced compacted dense sand tends to generate slightly lower values of ultimate footing settlement ratio, SRf, than those predicted using the lower-bound equation proposed here. Settlement characteristics of compacted sands, in contrast to the pluviated sands conventionally used for deriving experimental databases, may account for this discrepancy; this requires more study in the future. © 2011 Thomas Telford Ltd. Source


Shi B.,Wuhan University of Technology | Yan L.-X.,Wuhan University of Technology | Wu W.,National Cheng Kung University
Energy | Year: 2013

The growing concern over environmental considerations and the increasing fuel cost call for operating the energy station in a more economical and environmentally friendly way. This paper develops a multi-objective model for the CHPED (combined heat and power economic dispatch) problem to conventional energy stations, where the competing fuel cost and environmental impact objectives are simultaneously optimized. To model the problem accurately, both non-linear fuel cost functions with valve-point loading effects and power transmission loss are explicitly considered in this model. A novel MLCA (multi-objective line-up competition algorithm) is proposed to handle the problem as a nonlinear constrained multi-objective optimization problem. Some diversity-preserving mechanisms are employed in the MLCA to produce well-distributed Pareto-optimal solutions. Moreover, a fuzzy decision-making process is applied to extract the best compromise nondominated solution from the Pareto-optimal set. The performance of the proposed method is validated by two typical systems. Comparison results have demonstrated the superiority of the proposed approach and confirmed its potential to solve the larger multi-objective CHPED problem. © 2013 Elsevier Ltd. Source


Yang C.-C.,Southern Taiwan University of Science and Technology | Shieh M.-D.,National Cheng Kung University
Computers and Industrial Engineering | Year: 2010

In this paper, a state-of-the-art machine learning approach known as support vector regression (SVR) is introduced to develop a model that predicts consumers' affective responses (CARs) for product form design. First, pairwise adjectives were used to describe the CARs toward product samples. Second, the product form features (PFFs) were examined systematically and then stored them either as continuous or discrete attributes. The adjective evaluation data of consumers were gathered from questionnaires. Finally, prediction models based on different adjectives were constructed using SVR, which trained a series of PFFs and the average CAR rating of all the respondents. The real-coded genetic algorithm (RCGA) was used to determine the optimal training parameters of SVR. The predictive performance of the SVR with RCGA (SVR-RCGA) is compared to that of SVR with 5-fold cross-validation (SVR-5FCV) and a back-propagation neural network (BPNN) with 5-fold cross-validation (BPNN-5FCV). The experimental results using the data sets on mobile phones and electronic scooters show that SVR performs better than BPNN. Moreover, the RCGA for optimizing training parameters for SVR is more convenient for practical usage in product form design than the timeconsuming CV. © 2010 Elsevier Ltd. All rights reserved. Source


Lin Y.-H.,Chang Gung University | Lee G.-B.,National Cheng Kung University
Sensors and Actuators, B: Chemical | Year: 2010

This paper reports an integrated microfluidic device capable of performing online cell counting and continuous cell lysis by using an electric field induced by projected optical images. This device can be used to quantify the number of lysed cells, which is essential for molecular diagnosis. First, cells are hydrodynamically focused in the middle of a channel and then are counted using a pair of buried optical fibers. After cell counting, a projected optical image is used to induce an electric field, which arises from the use of a photoconductive material deposited on an indium-tin-oxide substrate. The cells can be lysed continuously due to the generation of a transmembrane potential. For cell counting, a total of 97 fibroblast cells have been perfectly counted without any miscounts. The optically induced electric field can be easily fine-tuned by adjusting the exposure time and the illumination power intensity. Experimental data showed 93.8% cells (45 out of 48 cells) are successfully lysed when they passed the projected optical patterns at an applied voltage of 7 Vpp and an illuminated power density of 100 kW/m2. The development of this integrated device provides a promising tool for a variety of applications for cell-based analysis and molecular diagnosis. © 2010 Elsevier B.V. All rights reserved. Source


Lin L.-Y.,National Cheng Kung University
Research in Autism Spectrum Disorders | Year: 2015

Abstract Little research focuses on the caregiving experiences of Taiwanese mothers of adolescents with autism spectrum disorder (ASD). The effects of the caregiving burden and coping strategies on the depressive symptoms of 60 of these mothers were examined. The adolescents they cared for ranged from 10 to 19 years old (mean age: 14.7 years). Mothers completed self-report written questionnaires. Findings indicated that greater use of problem-focused rather than emotion-focused coping was generally associated with lower levels of caregiver burden and fewer depressive symptoms. Problem-focused coping acted as a buffer when caregiving burdens were high. Specifically, actively confronting, planning, and suppressing competing activities as coping strategies moderated the effect of the caregiving burden on the depressive symptoms of these mothers. This significant buffering effect reflected adaptation to the caregiving burden. Awareness of the effects of coping strategies on maternal well-being could serve as a valuable guide for practitioners. © 2015 Elsevier Ltd. All rights reserved. Source


Chen M.-C.,National Cheng Kung University | Sonaje K.,National Tsing Hua University | Chen K.-J.,National Tsing Hua University | Sung H.-W.,National Tsing Hua University
Biomaterials | Year: 2011

Success in the oral delivery of therapeutic insulin can significantly improve the quality of life of diabetic patients who must routinely receive injections of this drug. However, oral absorption of insulin is limited by various physiological barriers and remains a major scientific challenge. Various technological solutions have been developed to increase the oral bioavailability of insulin. Having received considerable attention, nano-sized polymeric particles are highly promising for oral insulin delivery. This review article describes the gastrointestinal barriers to oral insulin delivery, including chemical, enzymatic and absorption barriers. The potential transport mechanisms of insulin delivered by nanoparticles across the intestinal epithelium are also discussed. Finally, recent advances in using polymeric nanoparticles for oral insulin delivery and their effects on insulin transport are reviewed, along with their future. © 2011 Elsevier Ltd. Source


Amine K.,Argonne National Laboratory | Kanno R.,Tokyo Institute of Technology | Tzeng Y.,National Cheng Kung University
MRS Bulletin | Year: 2014

This issue contains assessments of battery performance involving complex, interrelated physical and chemical processes between electrode materials and electrolytes. Transformational changes in battery technologies are critically needed to enable the effective use of renewable energy sources such as solar and wind to allow for the expansion of hybrid electric vehicles (HEVs) to plug-in HEVs and pure-electric vehicles. For these applications, batteries must store more energy per unit volume and weight, and they must be capable of undergoing many thousands of charge-discharge cycles. The articles in this theme issue present details of several growing interest areas, including high-energy cathode and anode materials for rechargeable Li-ion batteries and challenges of Li metal as an anode material for Li batteries. They also address the recent progress in systems beyond Li ion, including Li-S and Li-air batteries, which represent possible next-generation batteries for electrical vehicles. One article reviews the recent understanding and new strategies and materials for rechargeable Mg batteries. The knowledge presented in these articles is anticipated to catalyze the design of new multifunctional materials that can be tailored to provide the optimal performance required for future electrical energy storage applications. © 2014 Materials Research Society. Source


Perng S.-W.,Kun Shan University | Wu H.-W.,National Cheng Kung University
Applied Energy | Year: 2011

This study uses a projection finite element analysis with an element-by-element preconditioned conjugate gradient method to investigate the non-isothermal tapered flow channel installed with a baffle plate for enhancing cell performance in the cathodic side of a PEMFC. The parameters studies including tapered ratio (0.25 ∼ 1.0) and gap ratio (0.005 ∼ 0.2) on the cell performance have been explored in detail. The results indicate that the stronger composite effect of tapered flow channel and baffle blockage provides a better convection heat transfer performance and a higher fuel flow velocity and thus enhances the cell performance. © 2010 Elsevier Ltd. Source


Sou S.-I.,National Cheng Kung University
IEEE Communications Letters | Year: 2010

In this letter, we investigate the impact on connectivity metric when a power-saving model is applied to a vehicular network. An analytic model with linear time complexity is developed to compute the optimal number of active roadside units under a connectivity constraint. We provide guidelines for applying a power-saving model in a vehicular network. The results are very useful for the ministry of transportation. © 2006 IEEE. Source


Hung F.-Y.,National Cheng Kung University
Materials Transactions | Year: 2011

ZnO/In/ZnO tri-layer thin films were designed and fabricated by RF sputtering on copolymer substrate. Under an electrical current, the thermoelectric effect of direct current (DC) reduced the electrical resistance and improved the crystallization and Raman properties. Also, indium atoms had migrated into the ZnO matrix and a diffusion layer in the ZnO/In interface had grown. The electrical current induced temperature is ∼140°C and the copolymer substrate suffers no damage and so can be applied to the low temperature optoelectronic devices. © 2011 The Japan Institute of Metals. Source


Chung C.-H.,National Cheng Kung University | Robens T.,TU Dresden
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

In this work, we present the extension of an alternative subtraction scheme for next-to-leading order QCD calculations to the case of an arbitrary number of massless final state partons. The scheme is based on the splitting kernels of an improved parton shower and comes with a reduced number of final state momentum mappings. While a previous publication including the setup of the scheme has been restricted to cases with maximally two massless partons in the final state, we here provide the final state real emission and integrated subtraction terms for processes with any number of massless partons. We apply our scheme to three jet production at lepton colliders at next-to-leading order and present results for the differential C parameter distribution. © 2013 American Physical Society. Source


Liu Y.-C.,National Cheng Kung University | Chopra N.,University of Maryland University College
Journal of Dynamic Systems, Measurement and Control, Transactions of the ASME | Year: 2013

The problem of controlling a group of networked mechanical systems to synchronize and follow a common trajectory is studied in this paper. We first address the results for networked mechanical systems to achieve synchronization when the interagent communication graph is balanced and strongly connected with communication delays. Subsequently, a control law is developed to guarantee synchronization and trajectory tracking for networked mechanical systems communicating on regular graphs when there are constant time delays in communication and the interconnection topology is time-varying. The case when a human operator input is introduced in the closed-loop system is also considered. It is demonstrated that a bounded human operator input results in bounded tracking and synchronization errors, even when there are constant time delays in communication. The simulation and experimental results are presented by utilizing the kinematic and dynamic models of PHANToM Omni derived in this paper. Copyright © 2013 by ASME. Source


Pasko V.P.,Pennsylvania State University | Yair Y.,Open University of Israel | Kuo C.-L.,National Cheng Kung University
Space Science Reviews | Year: 2012

This paper presents a literature survey on the recent developments related to experimental and modeling studies of transient luminous events (TLEs) in the middle atmosphere termed elves, sprites and jets that are produced in association with thunderstorm activity at tropospheric altitudes. The primary emphasis is placed on publications that appeared in refereed literature starting from year 2008 and up to the present date. The survey covers general phenomenology of TLEs and their relationships to characteristics of individual thunderstorms and lightning, physical mechanisms and modeling of TLEs, past, present and future orbital observations of TLEs, and their chemical, energetic and electric effects on local and global scales. © 2011 Springer Science+Business Media B.V. Source


Chen C.-L.,National Cheng Kung University
Marine Policy | Year: 2012

This paper examines a case involving a mix of Territorial Use Rights in Fisheries, co-management and the competition for using coastal zones. In the 2000s, Taiwan's government initiated a remodeling of the fishery right system, which is a rights-based approach to fisheries management, as an attempt to address conflicts between fishers and developers regarding the use of coastal space and to put community-based co-management into practice. The paper particularly compares the system before and after 2000 and identifies areas of concern in the implementation of the remodeled system. The results show that the government's support for this system signifies progress in the right direction. However, concerns emerge, mostly involving fishers' low participation, fishermen's association's lack of technical skills and financial resources, and the division of management responsibility. The government is advised to play a more active role in dealing with these concerns. Finally, the paper reveals that the factor of competition for using coastal zones poses a challenge to co-management, and suggests a holistic view with integrated coastal management or marine spatial planning practices, for developing co-management under the fishery right system. © 2012 Elsevier Ltd. Source


Show K.-Y.,University Tunku Abdul Rahman | Lee D.-J.,National Taiwan University of Science and Technology | Chang J.-S.,National Cheng Kung University
Bioresource Technology | Year: 2011

Biohydrogen is regarded as an attractive future clean energy carrier due to its high energy content and environmental-friendly conversion. It has the potential for renewable biofuel to replace current hydrogen production which rely heavily on fossil fuels. While biohydrogen production is still in the early stage of development, there have been a variety of laboratory- and pilot-scale systems developed with promising potential. This work presents a review of advances in bioreactor and bioprocess design for biohydrogen production. The state-of-the art of biohydrogen production is discussed emphasizing on production pathways, factors affecting biohydrogen production, as well as bioreactor configuration and operation. Challenges and prospects of biohydrogen production are also outlined. © 2011 Elsevier Ltd. Source


Ren C.-Y.,National Kaohsiung Normal University | Cheng C.,National Cheng Kung University
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

The atomic and magnetic structures of (CuX)LaNb2O7 (X=Cl and Br) are investigated using the density functional calculations. Among several dozens of examined structures, an orthorhombic distorted 2×2 structure in which the displacement pattern of X halogens resembles the model conjectured previously based on the empirical information is identified as the most stable one. The displacements of X halogens, together with those of Cu ions, result in the formation of X-Cu-X-Cu-X zigzag chains in the two materials. Detailed analyses of the atomic structures predict that (CuX) LaNb 2O7 crystallizes in the space group Pbam. The nearest-neighbor interactions within the zigzag chains are determined to be antiferromagnetic (AFM) for (CuCl) LaNb2O7 but ferromagnetic (FM) for (CuBr) LaNb2O7. On the other hand, the first two neighboring interactions between the Cu cations from adjacent chains are found to be AFM and FM, respectively, for both compounds. The magnitudes of all these in-plane exchange couplings in (CuBr) LaNb 2O7 are evaluated to be about three times those in (CuCl) LaNb2O7. In addition, a sizable AFM interplane interaction is found between the Cu ions separated by two NbO6 octahedra. The fourth-neighbor interactions are also discussed. The present study strongly suggests the necessity to go beyond the square J1 - J2 model in order to correctly account for the magnetic property of (CuX) LaNb2O 7. © 2010 The American Physical Society. Source


Wu M.-L.,National Cheng Kung University
Microelectronics Reliability | Year: 2010

This paper emphasizes a rapid assessment methodology using by the design of experiments (DOE) to determine fatigue life of ball grid array (BGA) components in the random vibration environment. The most critical dynamic loading occurs when the dominant frequency approaches the natural frequency of the printed wiring board (PWB) assembly. This research has chosen to work within the PWB clamped on two opposite edges. One only needs to think of commercial personal portable electronic products such as cell phones, personal data assistants, and entertainment devices (as exemplified by the I-pod) to realize that electronic products are no longer exclusively used in a relatively benign office environment. The approach in this paper will involve global (entire PWB) and local (particular component of interest) modeling approach. In the global model approach, the vibration response of the PWB will be determined. This global model will give us the response of the PWB at specific component locations of interest. This response is then fed into a local stress analysis for accurate assessment of the critical stresses in the solder joints of interest. The stresses are then fed into a fatigue damage model to predict the life. The solution is achieved by using a combination of finite element analysis (FEA) and physics of failure to BGA damage analysis. © 2009 Elsevier Ltd. All rights reserved. Source


Lei C.U.,California Institute of Technology | Zhang W.-M.,National Cheng Kung University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

In this paper, we provide a mechanism of decoherence suppression for open quantum systems in general and that for a "Schrödinger cat-like" state in particular, through strong couplings to non-Markovian reservoirs. Different from the usual strategies in the literature of suppressing decoherence by decoupling the system from the environment, here the decoherence suppression employs a strong back-reaction from non-Markovian reservoirs. The mechanism relies on the existence of the singularities (bound states) of the nonequilibrium retarded Green function, which completely determines the dissipation and decoherence dynamics of open systems. As an application, we examine the decoherence dynamics of a photonic crystal nanocavity that is coupled to a waveguide. The strong non-Markovian suppression of decoherence for the "optical cat" state is attained. © 2011 American Physical Society. Source


Liu H.-S.,National Cheng Kung University
Journal of biomedical science | Year: 2014

BACKGROUND: We previously reported that Enterovirus 71 (EV71) infection activates autophagy, which promotes viral replication both in vitro and in vivo. In the present study we further investigated whether EV71 infection of neuronal SK-N-SH cells induces an autophagic flux. Furthermore, the effects of autophagy on EV71-related pathogenesis and viral load were evaluated after intracranial inoculation of mouse-adapted EV71 (MP4 strain) into 6-day-old ICR suckling mice.RESULTS: We demonstrated that in EV71-infected SK-N-SH cells, EV71 structural protein VP1 and nonstructural protein 2C co-localized with LC3 and mannose-6-phosphate receptor (MPR, endosome marker) proteins by immunofluorescence staining, indicating amphisome formation. Together with amphisome formation, EV71 induced an autophagic flux, which could be blocked by NH₄Cl (inhibitor of acidification) and vinblastine (inhibitor of fusion), as demonstrated by Western blotting. Suckling mice intracranially inoculated with EV71 showed EV71 VP1 protein expression (representing EV71 infection) in the cerebellum, medulla, and pons by immunohistochemical staining. Accompanied with these infected brain tissues, increased expression of LC3-II protein as well as formation of LC3 aggregates, autophagosomes and amphisomes were detected. Amphisome formation, which was confirmed by colocalization of EV71-VP1 protein or LC3 puncta and the endosome marker protein MPR. Thus, EV71-infected suckling mice (similar to EV71-infected SK-N-SH cells) also show an autophagic flux. The physiopathological parameters of EV71-MP4 infected mice, including body weight loss, disease symptoms, and mortality were increased compared to those of the uninfected mice. We further blocked EV71-induced autophagy with the inhibitor 3-methyladenine (3-MA), which attenuated the disease symptoms and decreased the viral load in the brain tissues of the infected mice.CONCLUSIONS: In this study, we reveal that EV71 infection of suckling mice induces an amphisome formation accompanied with the autophagic flux in the brain tissues. Autophagy induced by EV71 promotes viral replication and EV71-related pathogenesis. Source


Kao C.,National Cheng Kung University | Hwang S.-N.,Ming Chuan University
Decision Support Systems | Year: 2010

A recent development in DEA (data envelopment analysis) examines the internal structure of a system so that more information regarding sources that cause inefficiency can be obtained. This paper discusses a network DEA model which distributes the system inefficiency to its component processes. The model is applied to assess the impact of information technology (IT) on firm performance in a banking industry. The results show that the impact of IT on firm performance operates indirectly through fund collection. The impact increases when the IT budget is shared with the profit generation process. © 2009 Elsevier B.V. All rights reserved. Source


Two-dimensional principal component analysis (2DPCA) is implemented to analyze the total electron content (TEC) anomalies after Japan’s Tohoku earthquake that occurred at 05:46 on March 11, 2011 (UTC) (Mw=9). 2DPCA and TEC data processing were conducted just after this devastating earthquake. Analysis results show an earthquakeassociated TEC anomaly near the epicenter that began at 05:47. This may represent an extension of the precursor of the earthquake, to the precursor of China’s Wenchuan earthquake on May 12, 2008, detected by the study of Lin [2012], for which the data were obtained at a height of 150-200 km by the FORMOSAT-3 satellite system. It is impossible that such precursor caused by the acoustic shock waves. Another TEC anomaly near the epicenter occurred at 05:53, and this initiated the propagation of the tsunami effect related to the ionosphere through the acoustic shock waves from the epicenter. However, the TEC anomalies did not appear to be affected by a contemporaneous geomagnetic storm and other non-earthquake effects. The propagation of anomalous fluctuation could be an early warning of the tsunami for the regions far from the epicenter as it began to propagate with the higher speed of 3960-4950 km/h than the tsunami speed (720-800 km/h). © 2015 by the Istituto Nazionale di Geofisica e Vulcanologia. All rights reserved. Source


Chen H.-H.,National Cheng Kung University
IEEE Wireless Communications | Year: 2015

Dear readers, I have been serving as the Editor-in-Chief of IEEE Wireless Communications for almost three and a half years, and it is time for me to step down to take a break after days and nights of working hard for this magazine. My term as the Editor-in-Chief will officially end at the end of June 2015, and then the baton will be passed to Dr. Hamid Gharavi, National Institute of Standards and Technology (NIST), United States, who will be the next Editor-in-Chief of IEEE Wireless Communications. Therefore, I have invited Dr. Hamid Gharavi to write a message in this Editor's Note to mark this handover. In fact, Dr. Gharavi has been serving as Associate Editor-in-Chief for this magazine since June 2014. Therefore, the handover will definitely be a soft handover, ensuring that the editorial work of this magazine will continue seamlessly. Dr. Gharavi is a longtime IEEE volunteer, and I am fully confident that he has all the experience needed to bring this magazine to a new high level under his strong leadership. © 2015 IEEE. Source


Nishimura Y.,National Cheng Kung University
Computer Physics Communications | Year: 2011

An orbit following guiding center Monte Carlo calculation is presented which employs a general flux coordinate system in an axisymmetric plasma equilibrium. The calculation incorporates collision effects. Furthermore, a perturbation expansion is applied for the guiding center calculations in the presence of a frictional source. © 2010 Elsevier B.V. All rights reserved. Source


Hsu J.-Y.,National Cheng Kung University
Physics of Plasmas | Year: 2010

The equations governing the mode conversion between an electromagnetic wave and the plasma wave are derived from the relativistic Vlasov equation. They are further reduced to a two dimensional matrix equation involving only two electric field components. It is shown that the mode conversion efficiency diminishes to zero at both 0° and 90° of incidence angles, becomes insignificant beyond 45° and tends to improve with higher plasma temperature. © 2010 American Institute of Physics. Source


Hsieh P.-H.,National Cheng Kung University
Computers and Education | Year: 2010

This paper explores online instructors' perceptions on teaching experiences occurring in their own countries. The interviewees are instructors who have taught online courses for more than two years. Eleven interview transcripts, obtained from online instructors from six countries (Australia, Canada, China, United Kingdom, United States and Taiwan) were analyzed by using open and axial coding. The analysis of data established categories of perceptions related to: teachers' roles in the online environment, the methods for interacting with students, and teachers' expectations for their future educational careers. Finally, three perspectives arose which adequately describe online instructors' teaching experiences: interactive activities, evaluation criteria, and self-expectations. The study also reveals a link connecting those perspectives. © 2009 Elsevier Ltd. All rights reserved. Source


Chu H.-J.,National Cheng Kung University
International Journal of Applied Earth Observation and Geoinformation | Year: 2014

An extensive land cover change was triggered by a series of typhoons, especially Typhoon Morakot in 2009 in Taiwan. The normalized difference vegetation index (NDVI) series from multiple satellite images were applied to monitor the change processes of land cover. This study applied spatiotemporal analysis tools, including empirical orthogonal functions (EOF), and multiple variograms in analyzing space-time NDVI data, and detected the effects of large chronological disturbances in the characteristics of land cover changes. Spatiotemporal analysis delineated the temporal patterns and spatial variability of NDVI caused by these large typhoons. Results showed that mean of NDVI decreased but spatial variablity of NDVI increased after typhoons in the study area. The EOF can clarify the major component of NDVI variations and identify the core area of the NDVI changes. Various approaches showed consistent results that Typhoon Morakot significantly lowered the NDVI in land cover change process. Furthermore, the spatiotemporal analysis is an effective monitoring tool, which advocates the use of the index for the quantification of land cover change and resilience. © 2013 Elsevier B.V. Source


Chen K.R.,National Cheng Kung University
Optics Letters | Year: 2010

The diffraction limit sets the smallest achievable linewidth at half the wavelength. With a subwavelength plasmonic lens allowing one to reduce the diffraction via an asymmetry and to generate and squeeze the wave functions, an incident light is focused by the aperture to a single line with its width smaller than the limited value in the intermediate zone. The focused fields are capable of propagating in free space. This light focusing process, besides being of academic interest, is expected to open up a wide range of application possibilities. © 2010 Optical Society of America. Source


Tarn W.,Academia Sinica, Taiwan | Lai M.,National Cheng Kung University
Cell Division | Year: 2011

Regulation of cyclin levels is important for many cell cycle-related processes and can occur at several different steps of gene expression. Translational regulation of cyclins, which occurs by a variety of regulatory mechanisms, permits a prompt response to signal transduction pathways induced by environmental stimuli. This review will summarize translational control of cyclins and its influence on cell cycle progression.© 2011 Tarn and Lai; licensee BioMed Central Ltd. Source


Kawamori E.,National Cheng Kung University
Physics of Plasmas | Year: 2010

This paper derives a wave equation in magnetized plasma under electromagnetically induced transparency (EIT) regime for probe electron cyclotron wave. The equation has a solution indicating a state analogous to "dark-state polaritons" [M. Fleischhauer and M. D. Lukin, Phys. Rev. Lett. 84, 5094 (2000)] in quantum atomic system. The state analogous to dark-state polaritons is a propagating coupled state of the probe-wave electric field and longitudinal plasma oscillation. The propagation of the coupled state can be stopped as its waveform is maintained if injection of pump wave is properly controlled in time domain. The "stop-light" is achieved by adiabatic transition from a state in which the probe-wave field is dominant to a state in which the longitudinal plasma oscillation is dominant. This study also recaptures a phenomenon analogous to "coherent population trap" in conventional EIT of quantum atomic system. © 2010 American Institute of Physics. Source


Shiau D.-F.,Fooyin University | Huang Y.-M.,National Cheng Kung University
International Journal of Advanced Manufacturing Technology | Year: 2012

A proportionate flow shop (PFS) is a special case of the m machine flow shop problem. In a PFS, a fixed sequence of machines is arranged in s stages (samp;>1) with only a single machine at each stage, and the processing time for each job is the same on all machines. Notably, PFS problems have garnered considerable attention recently. A proportionate flexible flow shop (PFFS) scheduling problem combines the properties of PFS problems and parallelidentical-machine scheduling problems. However, few studies have investigated the PFFS problem. This study presents a hybrid two-phase encoding particle swarm optimization (TPEPSO) algorithm to the PFFS problem with a total weighted completion time objective. In the first phase, a sequence position value representation is designed based on the smallest position value rule to convert continuous position values into job sequences in the discrete PFFS problem. During the second phase, an absolute position value representation combined with a tabu search (TS) is applied starting from the current position of particles that can markedly improve swarm diversity and avoid premature convergence. The hybrid TPEPSO algorithm combines the cooperative and competitive characteristics of TPEPSO and TS. Furthermore, a candidate list strategy is designed for the TS to examine the neighborhood and concentrate on promising moves during each iteration. Experimental results demonstrate the robustness of the proposed hybrid TPEPSO algorithm in terms of solution quality. Moreover, the proposed hybrid TPEPSO algorithm is considerably faster than existing approaches for the same benchmark problems in literature. © Springer-Verlag London Limited 2011. Source


Chin W.-L.,National Cheng Kung University
IEEE Transactions on Vehicular Technology | Year: 2012

In this paper, blind symbol synchronization for orthogonal frequency-division multiplexing (OFDM) systems based on the cyclic prefix (CP), considering time-variant long-echo fading channels, is introduced. The basic idea of our contribution is to obtain an estimate of channel-tap powers using the correlation characteristics of the CP. The maximum-likelihood (ML) estimation of the correlation characteristics is derived and employed for channel-tap power estimation. An intersymbol-interference (ISI) metric is minimized using the estimate of channel-tap powers. The metric, which is based on the statistical properties of received samples, turns the mobility factor into a coefficient, which can be simply compensated. The metric is suitable for both short-and long-echo channels. The performance is analyzed. The proposed algorithm has moderate complexity. Simulations confirm the advantages of the proposed estimator. © 2011 IEEE. Source


Constantin A.,University of Vienna | Escher J.,Leibniz University of Hanover | Hsu H.-C.,National Cheng Kung University
Archive for Rational Mechanics and Analysis | Year: 2011

We study the pressure beneath a solitary water wave propagating in an irrotational flow at the free surface of water with a flat bed. The investigation is divided into two parts. The first part concerns a rigorous nonlinear study of the governing equations for water waves. We prove that the pressure in the fluid beneath a solitary wave strictly increases with depth and strictly decreases horizontally away from the vertical line beneath the crest. The second part of the paper describes an experimental study. Excellent agreement is found to exist between the theoretical predictions and the measurements. Our conclusions are also supported by numerical simulations. © 2011 Springer-Verlag. Source


Law S.S.C.,National Cheng Kung University | McDonald K.L.,University of Sydney
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

The seesaw mechanism can be generalized to a type-III variant and a quintuplet variant. We present two models that provide analogous generalizations of the inverse seesaw mechanism. The first model employs a real fermion triplet F∼(1,3,0) and requires no additional multiplets or parameters relative to the standard inverse seesaw. We argue that, from a bottom-up perspective, there appears to be no particular reason to preference the usual scenario over this variant. The second model employs a fermion quintuplet F∼(1,5,0) and requires an additional scalar S∼(1,4,1). We also show that minimal inverse seesaws with even larger fermionic representations are not expected to realize naturally small neutrino masses. © 2013 American Physical Society. Source


Law S.S.C.,National Cheng Kung University | McDonald K.L.,Max Planck Institute for Nuclear Physics
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2012

We show that models with exotic leptons transforming as E~. (1, 3, - 1) under the standard model gauge symmetry are well suited for generating neutrino mass via a radiative inverse seesaw. This approach realizes natural neutrino masses and allows multiple new states to appear at the TeV scale. The exotic leptons are therefore good candidates for new physics that can be probed at the LHC. Furthermore, remnant low-energy symmetries ensure a stable dark matter candidate, providing a link between dark matter and the origin of neutrino mass. © 2012 Elsevier B.V. Source


Kawamori E.,National Cheng Kung University
Physical Review Letters | Year: 2013

The wave number spectrum (one-dimensional spectrum) of electrostatic potential fluctuations at sub-Larmor scales was measured in two-dimensional (2D) electrostatic turbulence in laboratory magnetized plasma. The spectrum at scales k⊥ρi>1, where k⊥ and ρi are the fluctuation wave number perpendicular to the magnetic field and ion Larmor radius, respectively, supports the existence of the k -10/3 inertial range of the entropy cascade induced by nonlinear phase mixing. This indicates agreement with a theoretical prediction [A. A. Schekochihin et al., Plasma Phys. Controlled Fusion 50, 124024 (2008)PPCFET0741-3335] and the result of a 2D gyrokinetic simulation [T. Tatsuno et al., Phys. Rev. Lett. 103, 015003 (2009)PRLTAO0031-9007]. The cutoff wave numbers of the spectrum, above which the entropy cascade is smeared by collisions, observed in this experiment were consistent with those in the theory. © 2013 American Physical Society. Source


Li S.-T.,National Cheng Kung University | Cheng Y.-C.,Tainan University of Technology
IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics | Year: 2010

Recently, fuzzy time series have attracted more academic attention than traditional time series due to their capability of dealing with the uncertainty and vagueness inherent in the data collected. The formulation of fuzzy relations is one of the key issues affecting forecasting results. Most of the present works adopt IFTHEN rules for relationship representation, which leads to higher computational overhead and rule redundancy. Sullivan and Woodall proposed a Markov-based formulation and a forecasting model to reduce computational overhead; however, its applicability is limited to handling one-factor problems. In this paper, we propose a novel forecasting model based on the hidden Markov model by enhancing Sullivan and Woodall's work to allow handling of two-factor forecasting problems. Moreover, in order to make the nature of conjecture and randomness of forecasting more realistic, the Monte Carlo method is adopted to estimate the outcome. To test the effectiveness of the resulting stochastic model, we conduct two experiments and compare the results with those from other models. The first experiment consists of forecasting the daily average temperature and cloud density in Taipei, Taiwan, and the second experiment is based on the Taiwan Weighted Stock Index by forecasting the exchange rate of the New Taiwan dollar against the U.S. dollar. In addition to improving forecasting accuracy, the proposed model adheres to the central limit theorem, and thus, the result statistically approximates to the real mean of the target value being forecast. © 2010 IEEE. Source


Two-dimensional ionospheric total electron content (TEC) data during the time period from 00:00 on 2 July to 12:00 UT on 8 July 2013, which was 5 days before to 1 day after a deep earthquake at 18:35:30 on 7 July 2013 UT (Mw = 7.2) with a depth at about 378.8 km in Papua New Guinea, were examined by two-dimensional principal component analysis (2DPCA) to detect TEC precursor related to the earthquake because TEC precursors usually have shown up in earlier time periods. A TEC precursor was highly localized around the epicenter from 06:00 to 06:05 on 6 July, where its duration time was at least 5 minutes. Ionizing radiation radon gas release should be a possibility to cause the anomalous TEC fluctuation, e.g., electron density variation. The plasma might have large damping at that time to cause TEC fluctuation of short time, and the gas released with small amount in short time period, and 2DPCA could identify short time TEC fluctuation while the fluctuation lasted for a long time. Other background TEC anomalies caused by the geomagnetic storm, small earthquakes and non-earthquake activities, e.g., equatorial ionization anomaly resulted in the small principal eigenvalues, therefore the detection of TEC precursor was regardless of these background TEC anomalies. © 2014 Taylor & Francis. Source


Pai F.-S.,National University of Tainan | Chao R.-M.,National Cheng Kung University
IEEE Transactions on Energy Conversion | Year: 2010

One of critical concerns in the operation of the photovoltaic system is the maximum power point (MPP) tracking problem that increases the economical feasibility of the system. This letter presents a tracking method using the quadratic polynomial to perform a MPP tracker of a given photovoltaic array. With the method, the maximum power calculation ismade froma quadratic manner that it convergences significantly accelerated. © 2009 IEEE. Source


Chang W.-J.,National Cheng Kung University
Soil Dynamics and Earthquake Engineering | Year: 2011

The evaluation of shear strains under multi-directional shaking is an important issue in interpreting dynamic soil behavior for both laboratory physical modeling and in situ monitoring. Shear strain components evaluated from Cartesian coordinates in undrained conditions have limitations to fully capture the coupled shear strain-pore pressure responses with an individual expression. In the present study, radial and rotational shear strain components derived from particle motions described with cylindrical polar coordinates are proposed. The proposed radial and rotational shear strains are verified with data from a bi-directional laminar shear box and a free field downhole array. Comparison results show that the proposed expressions of shear strain effectively capture the coupled strain-pore pressure responses in terms of the frequency content, amplitude variation, phase difference, and oscillation behavior. Comparison results reveal that the radial shear strain is the dominant shearing mode and the amplitude of the rotational shear strain is only 6.5-14.5% of the radial component. This provides quantitative data for the correction factor for multi-directional shaking and suggests that a simple shear system capable of inducing the radial shear strain on the vertical plane is a better approach than other shearing modes for physically modeling the behavior of soil subjected to undrained seismic loadings. © 2011 Elsevier Ltd. Source


Shiah Y.C.,National Cheng Kung University
Computer Methods in Applied Mechanics and Engineering | Year: 2014

In the boundary element method (BEM), it is well known that the presence of body force shall give rise to an additional volume integral that conventionally requires domain discretization for numerical computations. To restore the BEM's distinctive notion of boundary discretization, the present work analytically transforms the volume integral to surface ones for the body-force effect in the 3D anisotropic elasticity. On applying Green's Theorem, new fundamental solutions with explicit forms of Fourier series are introduced to facilitate the volume-to-surface transformation. The coefficients of the Fourier-series representations are determined by solving a banded matrix formulated from integrations of the constrained equation. Of no doubt, such an approach has fully restored the boundary element method as a truly boundary solution technique for analyzing 3D anisotropic elasticity involving body force. At the end, numerical verifications of the volume-to-surface integral transformation are presented. Also, such an approach has been implemented in an existing BEM code. For demonstrating the implementation, numerical examples are presented with comparisons with ANSYS analysis. To the author's knowledge, this is the first work in the open literature that reports the successful transformation for 3D anisotropic elasticity. © 2014 Elsevier B.V. Source


Huang C.C.,National Cheng Kung University
Geosynthetics International | Year: 2016

To investigate the effectiveness and limitations of using a reinforced earth slab to mitigate excessive footing settlements induced by an unloading at the slope toe, two-dimensional model slope tests were performed. Model slopes sustaining a constant footing load at the slope crest were brought to failure by progressively unloading at the slope toe. A rigid wall was jointed to a screw jack to apply constant displacement rate translational movement of the rigid wall to simulate typical conditions of slope toe excavation. Test results revealed that the toe unloading-induced settlement of a footing can be significantly reduced by using two layers of geosynthetic reinforcement under the footing, provided that the height of toe unloading (H) is less than the threshold value (Hc). For a cohesionless slope subjected to a footing load at the crest, the threshold unloading height can be significantly increased (by 64%) by incorporating two layers of geosynthetic reinforcement under the footing. Test results also revealed that both the stability of a footing and the locus of points of maximum tensile reinforcement force are strongly influenced by the location of the active slip plane developed behind the zone of toe unloading. © 2015 Thomas Telford Ltd. Source


Huang C.-C.,National Cheng Kung University
International Journal of Rock Mechanics and Mining Sciences | Year: 2016

A cost- and time-effective procedure for back-calculating the strength and deformation properties of natural slopes consisting of highly weathered or jointed rocks is of high practical importance. A novel procedure is proposed which incorporates a limit-equilibrium-based slice method to derive strength parameters for soils and weathered rocks and a force-equilibrium-based finite displacement method (FFDM) to derive the displacement-related material parameters for a deep-seated sliding mass. Various failure criteria for soils and rocks are used in back-calculating the strength parameters for a studied slope. First, the displacement-related parameters are back-calculated based on the measured slope displacement triggered by an intensive rainfall. These back-calculated strength and displacement parameters are then used to predict slope displacements induced by subsequent events of rainfall. The effectiveness of the proposed procedure is verified based on the case history of a natural slope subjected to periodic rainfall-induced slope movements. © 2016 Elsevier Ltd Source


Fang C.,National Cheng Kung University | Wu W.,University of Natural Resources and Life Sciences, Vienna
Acta Geotechnica | Year: 2014

The complete thermodynamically consistent turbulent closure models of isochoric and isothermal dry granular dense flows with incompressible grains and weak turbulent intensity are established on the basis of a linearized theory with respect to the granular coldness for the dynamic responses of the closure conditions. The models are applied to study a gravity-driven stationary turbulent flow down an inclined moving plane, and the numerical simulations are compared with the experimental outcomes. It shows that while the mean velocity decreases monotonically from its boundary value on the moving plane toward the free surface, the mean porosity and granular coldness display more “exponential-like” increasing/decreasing tendencies. Of particular interest is that the granular coldness evolves from its maximum value on the moving plane toward its minimum value on the free surface, leading to the turbulent dissipation evolving in a similar manner, while the turbulent kinetic energy demonstrate a reverse tendency. The obtained results show good agreements to the experimental outcomes and are similar to the characteristics of conventional Newtonian fluids in turbulent shear flows. © 2014, Springer-Verlag Berlin Heidelberg. Source


Hwang G.-J.,National Taiwan University of Science and Technology | Wu P.-H.,National Cheng Kung University | Ke H.-R.,National University of Tainan
Computers and Education | Year: 2011

Mobile and wireless communication technologies not only enable anytime and anywhere learning, but also provide the opportunity to develop learning environments that combine real-world and digital-world resources. Nevertheless, researchers have indicated that, without effective tools for helping students organize their observations in the field, the mobile learning performance could be disappointing. To cope with this problem, this study proposes an interactive concept map-oriented approach for supporting mobile learning activities. An experiment has been conducted on an elementary school natural science course to evaluate the effectiveness of the proposed method. The experimental results show that the proposed approach not only enhances learning attitudes, but also improves the learning achievements of the students. © 2011 Elsevier Ltd. All rights reserved. Source


Shen H.-N.,Chi Mei Medical Center | Shen H.-N.,National Cheng Kung University
Critical Care Medicine | Year: 2016

OBJECTIVES:: To examine the risk of recurrence in adults who survived first-episode severe sepsis for at least 3 months. DESIGN:: A matched cohort study. SETTING:: Inpatient claims data from Taiwan’s National Health Insurance Research Database. SUBJECTS:: We analyzed 10,818 adults who survived first-episode severe sepsis without recurrence for at least 3 months in 2000 (SS group; mean age, 62.7 yr; men, 54.7%) and a group of age/sex-matched (1:1) population controls who had no prior history of severe sepsis. All subjects were followed from the study entry to the occurrence of end-point, death, or until December 31, 2008, whichever date came first. INTERVENTIONS:: None. MEASUREMENTS AND MAIN RESULTS:: Primary end-point was severe sepsis that occurred after January 1, 2001 (the study entry). Relative risk of the end-point was assessed using competing risk regression model. During the follow-up period, severe sepsis and death occurred in 35.0% and 26.5% of SS group and in 4.3% and 18.6% of controls, respectively, representing a covariate-adjusted sub–hazard ratio of 8.89 (95% CI, 8.04–9.83) for the risk of recurrence. In stratified analysis by patient characteristics, the sub–hazard ratios ranged from 7.74 in rural area residents to 23.17 in young adults. In subgroup analysis by first-episode infection sites in SS group, the sub–hazard ratios ranged from 4.82 in intra-abdominal infection to 9.99 in urinary tract infection. CONCLUSIONS:: Risk of recurrence after surviving severe sepsis is substantial regardless of patient characteristics or infection sites. Further research is necessary to find underlying mechanisms for the high risk of recurrence in these patients. Copyright © by 2016 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved. Source


BACKGROUND:: The anterior cingulate cortex (ACC) is a brain region that has been critically implicated in the processing of pain perception and modulation. While much evidence has pointed to an increased activity of the ACC under chronic pain states, less is known about whether pain can be alleviated by inhibiting ACC neuronal activity. METHODS:: The authors used pharmacologic, chemogenetic, and optogenetic approaches in concert with viral tracing technique to address this issue in a mouse model of bone cancer–induced mechanical hypersensitivity by intratibia implantation of osteolytic fibrosarcoma cells. RESULTS:: Bilateral intra-ACC microinjections of γ-aminobutyric acid receptor type A receptor agonist muscimol decreased mechanical hypersensitivity in tumor-bearing mice (n =10). Using adenoviral-mediated expression of engineered Gi/o-coupled human M4 (hM4Di) receptors, we observed that activation of Gi/o-coupled human M4 receptors with clozapine-N-oxide reduced ACC neuronal activity and mechanical hypersensitivity in tumor-bearing mice (n = 11). In addition, unilateral optogenetic silencing of ACC excitatory neurons with halorhodopsin significantly decreased mechanical hypersensitivity in tumor-bearing mice (n = 4 to 9), and conversely, optogenetic activation of these neurons with channelrhodopsin-2 was sufficient to provoke mechanical hypersensitivity in sham-operated mice (n = 5 to 9). Furthermore, we found that excitatory neurons in the ACC send direct descending projections to the contralateral dorsal horn of the lumbar spinal cord via the dorsal corticospinal tract. CONCLUSIONS:: The findings of this study indicate that enhanced neuronal activity in the ACC contributes to maintain bone cancer–induced mechanical hypersensitivity and suggest that the ACC may serve as a potential therapeutic target for treating bone cancer pain. Copyright © by 2016, the American Society of Anesthesiologists, Inc. Wolters Kluwer Health, Inc. All Rights Reserved. Source


Cheng Y.-H.,National Cheng Kung University
Transportation | Year: 2010

Although people are often encouraged to use public transportation, the riding experience is not always comfortable. This study uses service items to measure passenger anxieties by applying a conceptual model based on the railway passenger service chain perspective. Passenger anxieties associated with train travel are measured using a modern psychometric method, the Rasch model. This study surveys 412 train passengers. Analytical results indicate that the following service items cause passenger anxiety during trains travel: crowding, delays, accessibility to a railway station, searching for the right train on a platform, and transferring trains. Empirical results obtained using the Rasch approach can be used to derive an effective strategy to reduce train passenger anxiety. This empirical study also demonstrates that anxiety differs based on passenger sex, age, riding frequency, and trip type. This information will also prove useful for transportation planners and policy-makers when considering the special travel needs of certain groups to create a user-friendly railway travel environment that promotes public use. © 2010 Springer Science+Business Media, LLC. Source


Pan D.,National Cheng Kung University
Numerical Heat Transfer, Part B: Fundamentals | Year: 2010

A simple, stable, and accurate ghost cell method is developed to solve the incompressible flows over immersed bodies with heat transfer. A two-point stencil is used to build the flow reconstruction models for both Dirichlet and Neumann boundary conditions on the immersed surface. Tests show that the current scheme is second-order-accurate in all error norms for both types of boundary condition, with the only exception that under Neumann condition the order of the maximum norm of temperature error is 1.44. Various forced- and natural-convection problems for cylinders immersed in open field or in a cavity are computed and compared with published data. Copyright © Taylor & Francis Group, LLC. Source


Chang C.-C.,National Cheng Kung University
Applied Energy | Year: 2010

This paper uses multivariate co-integration Granger causality tests to investigate the correlations between carbon dioxide emissions, energy consumption and economic growth in China. Some researchers have argued that the adoption of a reduction in carbon dioxide emissions and energy consumption as a long term policy goal will result in a closed-form relationship, to the detriment of the economy. Therefore, a perspective that can make allowances for the fact that the exclusive pursuit of economic growth will increase energy consumption and CO2 emissions is required; to the extent that such growth will have adverse effects with regard to global climate change. © 2010 Elsevier Ltd. Source


Chen C.-H.,National Cheng Kung University | Chen C.-H.,National Center for Theoretical science
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2010

The evidence of a large CP phase has been shown by CDF and DØ collaborations in the time-dependent CP asymmetry (CPA) of Bs → J / Ψ φ{symbol} decay, where the nonvanished CPA clearly implies the existence of a non-Kobayashi-Maskawa phase in b → s transition. We study the new phases originated by the extra family-dependent U (1)′ model and examine their impact on over(T, ̂) or CP violating observables in over(B, ̄)q → Vq ℓ+ ℓ- decays with Vq = K* (φ{symbol}). Adopting the constraints from the current data of Δ ms and the branching ratios for over(B, ̄)s → μ+ μ- and over(B, ̄)q → Vq ℓ+ ℓ-, we find that φ{symbol}s J / Ψ φ{symbol} = - (0.26 ± 0.22) and the T-odd observables of above 10% in the decay chain over(B, ̄)q → Vq (→ K π [K K]) ℓ+ ℓ- can be achieved. In addition, we demonstrate that the longitudinal and transverse polarizations of K* and the up-down asymmetry of K in the same decay chain are also sensitive to the Z′-mediated effects. © 2009 Elsevier B.V. All rights reserved. Source


Lee W.-H.,National Cheng Kung University
Journal of Hypertension | Year: 2016

OBJECTIVE:: Global longitudinal strain is not well illustrated for the prognostic value in hypertension. This observational study investigated the prognostic value of global longitudinal strain, subendocardial longitudinal strain, and subepicardial (EpiLS) longitudinal strain in regularly treated hypertensive patients. METHODS:: Ninety-five hypertensive study participants (60.0% men, age 65.5?±?12.0 years) were regularly treated for more than 1 year. We performed a two-dimensional echocardiographic study and obtained global peak systolic left ventricular longitudinal strain of subendocardial myocardium and the subepicardium (defined as subendocardial longitudinal strain and EpiLS, respectively). Cardiovascular events included cardiovascular death and any admission for stroke, acute coronary syndrome, or heart failure. RESULTS:: After a follow-up period of 7.3?±?2.0 years, 20 (21%) study participants had cardiovascular events. Significant differences between study participants with and without cardiovascular events were noted in diuretic administration (75.0 vs. 93.3%, P?=?0.018), age (71.0?±?11.6 vs. 64.0?±?11.8 years, P?=?0.02) and EpiLS (−16.0?±?2.0 vs. −17.7?±?3.0%, P?=?0.04). Using multivariate Cox regression analysis, EpiLS was the only independent prognostic factor (hazard ratio 1.449, 95% confidence interval 1.027–2.045, P?=?0.035). Using the cut off value of −17.57% for EpiLS (median value of EpiLS), the Kaplan–Meier survival curve revealed a significant difference (P?=?0.016) associated with cardiovascular outcome. CONCLUSION:: EpiLS was the only independent prognostic factor in regularly-treated hypertensive patients. Our results indicated that involvement of subepicardial myocardium may infer worse prognosis of hypertensive heart disease. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. Source


Hsieh S.,National Cheng Kung University | Wu M.,National Chung Cheng University
Brain Research | Year: 2011

The ability to flexibly shift between tasks is central to cognitive control, but whether the same brain mechanisms mediate shifting across different tasks is unknown. In this study, we investigated whether variations in stimulus-dimensions or response-mapping might influence task switching in terms of its preparatory processes, as reflected in cue-locked event-related potentials (ERPs), and its implementation processes, as reflected in stimulus-locked ERPs. Participants judged pairs of digits as same or different in one of two conditions. In one condition, the task-relevant stimulus-dimension was either repeated or switched across trials while the response-mapping rule was kept constant. In the other condition, the task-relevant stimulus-dimension was kept constant while the response-mapping rule was repeated or switched across trials. The length of the preparatory interval was manipulated. Data revealed switch-related preparatory ERP components (including N2 and a late slow positivity) that were associated with both types of task shifting and an N400-like negativity that distinguished between the two types. Several switch-related implementation ERP components associated with both types of task shifting were found at posterior sites. Distinct frontal modulations of the N1, P2, and N2 were found to associate with the implementation of the response-mapping shift, whereas a slow positivity was associated with the implementation of the stimulus-dimension shift. Therefore, this study demonstrates that there are shared and distinct processes across different types of task shifting. Finally, because the same transition-cue was used for different task shifts, the distinct processes cannot be explained simply by differences in cue processing. © 2011 Elsevier B.V. Source


ZNF322A encoding a classical Cys2His2 zinc finger transcription factor was previously revealed as a potential oncogene in lung cancer patients. However, the oncogenic role of ZNF322A and its underlying mechanism in lung tumorigenesis remain elusive. Here we show ZNF322A protein overexpression in 123 Asian and 74 Caucasian lung cancer patients. Multivariate Cox regression analysis indicated that ZNF322A was an independent risk factor for a poor outcome in lung cancer, corroborating the Kaplan–Meier results that patients with ZNF322A protein overexpression had significantly poorer overall survival than other patients. Overexpression of ZNF322A promoted cell proliferation and soft agar growth by prolonging cell cycle in S phase in multiple lung cell lines, including the immortalized lung cell BEAS-2B. In addition, ZNF322A overexpression enhanced cell migration and invasion, whereas knockdown of ZNF322A reduced cell growth, invasion and metastasis abilities in vitro and in vivo. Quantitative proteomic analysis revealed potential ZNF322A-regulated downstream targets, including alpha-adducin (ADD1), cyclin D1 (CCND1), and p53. Using luciferase promoter activity assay combined with site-directed mutagenesis and sequential chromatin immunoprecipitation-PCR assay, we found that ZNF322A could form a complex with c-Jun and cooperatively activate ADD1 and CCND1 but repress p53 gene transcription by recruiting differential chromatin modifiers, such as histone deacetylase 3, in an AP-1 element dependent manner. Reconstitution experiments indicated that CCND1 and p53 were important to ZNF322A-mediated promotion of cell proliferation, whereas ADD1 was necessary for ZNF322A-mediated cell migration and invasion. Our results provide compelling evidence that ZNF322A overexpression transcriptionally dysregulates genes involved in cell growth and motility therefore contributes to lung tumorigenesis and poor prognosis.Oncogene advance online publication, 17 August 2015; doi:10.1038/onc.2015.296. © 2015 Macmillan Publishers Limited Source


Tsai S.C.,National Cheng Kung University
INFORMS Journal on Computing | Year: 2013

Some existing simulation optimization algorithms (e.g., adaptive random search) become pure random search methods and thus are ineffective for the zero-one optimization via simulation problem. In this paper, we present highly efficient rapid screening procedures for solving the zero-one optimization via simulation problem. Three approaches adopting different sampling rules and providing different statistical guarantees are described. We also propose efficient neighborhood search methods and a simple algorithm for generation of initial solutions, all of which can be incorporated into our rapid screening procedures. The proposed procedures are more adaptive than ordinary ranking and selection procedures because in each iteration they can eliminate inferior solutions and intelligently sample promising solutions from the neighborhood of the survivors. Empirical studies are performed to compare the efficiency of the proposed procedures with other existing ones. © 2013 INFORMS. Source


Huang C.-C.,National Cheng Kung University
Geosynthetics International | Year: 2013

An understanding of the vertical acceleration response of geosynthetic-reinforced slopes subjected to horizontal input ground excitations is essential to robust seismic design. A series of stepwise intensified shaking tests was performed using simple sinusoidal waves with various horizontal peak ground accelerations (HPGA = 0.2-1.0g where g = gravitational acceleration) and wave frequencies (f = 3, 6 and 15 Hz) to investigate vertical acceleration responses at the crest of a reinforced model slope subjected to horizontal input ground excitations. Vertical accelerations at the edge of the slope crest (av1) occurred under relatively small HPGA associated with a negligibly small displacement of the slope. A large vertical acceleration of the unreinforced zone (av2) occurred under relatively large HPGA associated with a large displacement of the slope. Measured horizontal peak acceleration (ahp) against vertical peak acceleration (avp) at the crest of the slope indicate that values of avp under a specific HPGA increase with increasing input wave frequency. At the verge of the ultimate displacement state, values of avp at the crest of the unreinforced zone were consistently greater than those for the crest of the reinforced zone, suggesting that a downward slump of the failure wedge behind the reinforced zone occurred at the ultimate displacement state of the slope. Pseudo-static stability analyses were performed for the tested slopes based on the observed range of vertical-to-horizontal acceleration ratio (o) at the crest of slopes loaded with f = 3 and 6 Hz. It was shown that the influence of o on the critical seismic coefficient (khc) of the slope increases with increasing reinforcement force. Values of khc decreased by 8-30% when o increased from 0 to +1.5, indicating that a vertical acceleration induced by the slump of the soil mass plays a role in destabilising the slope and/or in increasing the plastic displacement of the slope. © 2013 Thomas Telford Ltd. Source


Ju S.H.,National Cheng Kung University
Bulletin of the Seismological Society of America | Year: 2013

This paper proposes a nonlinear time-domain finite-element method to generate three-direction seismic loads on the mesh boundary using the measured ground surface acceleration. The proposed scheme obtains correct earthquake responses around the major soil-structure interaction (SSI) region. The applied acceleration at the mesh bottom is first approximated as the measured acceleration on the soil surface. A time-domain finite-element analysis and a de convolution scheme are then performed to find the seismic acceleration at the mesh bottom. After several iterations, these acceleration data can be convergent to an acceptable accuracy. This paper also investigates the viscous and absorbing boundary methods to avoid fake reflection along the mesh boundary. The viscous boundary method is simple and can be applied to a standard finite-element code without difficulty; moreover, this scheme is also acceptably accurate, if appropriate damping is used in the interface layer. Thus, the viscous boundary method is suggested for use in the SSI analysis with the earthquake loading. Source


Huang C.-C.,National Cheng Kung University
Engineering Geology | Year: 2013

Conventional slice methods of slope stability use a constant value of safety factor along the entire failure surface, providing no information of displacements and possible variations about safety margins for the analyzed slope. Therefore, it is of practical significance to extend the force-based slice method into a displacement-based one to provide useful information about shear displacements and associated safety margins along the potential failure surface. This study extends Janbu's Generalized Procedure of Slices (GPS) by supplementing force and moment equilibrium and the Mohr-Coulomb failure criterion, which are employed in the Janbu's GPS, with additional criteria regarding slice displacement compatibility and non-linear stress-displacement relationships represented by a hyperbolic soil model. The extended displacement-based slice method constitutes a statically determinate system which is capable of generating local stress- and displacement-based safety factors along a potential failure surface. The principles and procedures proposed here can also be applied to other slice methods, regardless of their accuracy. Results of a case study show that the observed slope displacement induced by a ground table rise during a rainstorm event can be well simulated using the proposed method. More case studies into various mechanisms of slope displacements will be performed in the future to validate the proposed method for practical engineering applications. © 2013 Elsevier B.V.. Source


Hsu C.-L.,National University of Tainan | Chang S.-J.,National Cheng Kung University
Small | Year: 2014

In the past decades, the doping of ZnO one-dimensional nanostructures has attracted a great deal of attention due to the variety of possible morphologies, large surface-to-volume ratios, simple and low cost processing, and excellent physical properties for fabricating highperformance electronic, magnetic, and optoelectronic devices. This article mainly concentrates on recent advances regarding the doping of ZnO one-dimensional nanostructures, including a brief overview of the vapor phase transport method and hydrothermal method, as well as the fabrication process for photodetectors. The dopant elements include B, Al, Ga, In, N, P, As, Sb, Ag, Cu, Ti, Na, K, Li, La, C, F, Cl, H, Mg, Mn, S, and Sn. The various dopants which act as acceptors or donors to realize either p-type or n-type are discussed. Doping to alter optical properties is also considered. Lastly, the perspectives and future research outlook of doped ZnO nanostructures are summarized. © 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Ju S.H.,National Cheng Kung University
Soil Dynamics and Earthquake Engineering | Year: 2013

This study developed a finite element method with the effect of soil-fluid-structure interaction to calculate bridge natural frequencies. The finite element model includes bridge girders, piers, foundations, soil, and water. The effective mass above the soil surface was then used to find the first natural frequency in each direction. A field experiment was performed to validate that the natural frequencies calculated using the proposed finite element method had acceptable accuracy. The calculated natural frequencies with the fluid-structure interaction effect are always smaller than those without this effect. However, the frequency change due to the fluid effect is not obvious, so using the soil-structure interaction model is accurate enough in the bridge natural frequency analysis. The trend of the frequency decreases with the increase of the scour depth, but the curve is not smooth because of non-uniform foundation sections and layered soils. However, when the scour depth is such that pile cap is exposed, the changes in natural frequency with the scour depth are more obvious, and this is useful for measurement of the depth using bridge natural frequencies. © 2013 Elsevier Ltd. Source


Nakazawa T.,National Cheng Kung University
Population Ecology | Year: 2015

Almost all organisms on Earth exhibit ontogenetic niche shifts, which causes great phenotypic variation among individuals and is thus considered to critically mediate community structure and dynamics. In contrast, community ecology has traditionally assumed that species are composed of identical individuals with invariant traits and ignored the potentially important ecological roles of ontogenetic niche shifts. To bridge the gap, here I briefly review ecologically relevant examples which show that basic insights of species-based community theories can be revised by including the ontogenetic perspective. Specifically, I focus on the most representative animals in the study of ontogenetic niche shifts, i.e., fish, insects, and amphibians. Notably, their ontogenetic niche shifts create novel views of community structure: (1) ontogenetic diet shifts of predatory fish couple pelagic and benthic food webs in aquatic systems, (2) ontogenetic shifts in interaction types of pollinating insects couple herbivory and pollination networks in terrestrial systems, and (3) ontogenetic habitat shifts of amphibians and aquatic insects couple aquatic and terrestrial metacommunities at interface areas. Dynamic models of such stage-structured communities suggest that their ontogenetic niche shifts may affect the community resilience and disturbance responses. Exploring more complex systems (e.g., where many species undergo ontogenetic niche shifts several times or continuously) is a future direction, for which describing body size relationships between interacting organisms would be a promising approach. I conclude that both theoretical and empirical advances are needed to facilitate the ontogenetic perspective for better understanding mechanisms underlying biodiversity and ecosystem functioning which are increasingly threatened by anthropogenic disturbance. © 2014, The Society of Population Ecology and Springer Japan. Source


Wu H.-W.,National Cheng Kung University
Applied Energy | Year: 2016

This study reviews technical papers on transport and performance modeling of proton exchange membrane (PEM) fuel cells during the past few years. The PEM fuel cell is a promising alternative power source for various applications in stationary power plants, portable power device, and vehicles. PEM fuel cells provide low operating temperatures and high-energy efficiency with zero emissions. A PEM fuel cell is a multiple distinct parts device and a series of mass, momentum and energy transport through gas channels, electric current transport through membrane electrode assembly and electrochemical reactions at the triple-phase boundaries. These transport processes play crucial roles to determine electrochemical reactions and cell performance, so studies on the transport and performance modeling have been done deeply. This review shows how these modeling studies offer valid findings for transport and performance modeling of PEM fuel cells and recommendations that can be applied in enhancing transport processes for improving the cell performance. © 2015 Elsevier Ltd. Source


Sato S.,Zikei Institute of Psychiatry | Yeh T.L.,National Cheng Kung University
CNS Drugs | Year: 2013

Major depressive disorder (MDD) is frequently unrecognized and underdiagnosed by clinicians and thus remains untreated or inappropriately treated in routine clinical practice. Although the symptoms of MDD are widely acknowledged and recognized by clinicians, numerous epidemiological studies have reported that this disorder is more prevalent than had previously been thought, and that it is challenging to diagnose and treat, particularly because somatic symptoms and comorbid conditions are common in real clinical situations. MDD is associated with increased morbidity and mortality as well as with higher healthcare costs and more severe functional impairment. Therefore, optimal treatment for MDD should include collaboration focussed on comorbid physical diseases, rehabilitation aimed at restoring social functioning, and pharmacotherapy designed to ensure complete remission including psychological and physical symptoms, as well as functional recovery. © Springer International Publishing Switzerland 2013. Source


This study employed two-dimensional Principal Component Analysis (2DPCA) and Principal Component Analysis (PCA) to examine the total electron content (TEC) in the ionosphere 5 days prior to the deep Tobelo earthquake. This event occurred at 15:05:37 on 26 August 2012 (UT) (M w =6.6) at a depth of 91.9 km near Indonesia. Using 2DPCA, a TEC precursor was identified near the epicenter of the earthquake lasting at least 10 minutes, from 06:10 to 06:20 on 24 August 2012 (UT). One possible cause for a TEC precursor of such short duration could be the high initial speed of released radon gas. © 2013 Akadémiai Kiadó, Budapest, Hungary. Source


Chen W.-T.,National Cheng Kung University
IEEE Transactions on Vehicular Technology | Year: 2016

This paper proposes an efficient anti-collision algorithm to improve the read performance of the EPCglobal ultra-high frequency (UHF) Class-1 Generation-2 radio-frequency identification (RFID) standard. Optimal frame length is one of the most important parameters to be adjusted in RFID anti-collision algorithms. Hence, we first derive the optimal frame length by analyzing the maximum of normalized throughput and by taking into account the unequal time intervals of successful, collision, and empty slots. We find that the optimal frame length should be set to 1.89 times of the number of tags when the ratio between collision-slot duration and empty-slot duration is 5. The proposed anti-collision algorithm is based on the mechanism of early adjustment of frame length and examines the fitness of frame length only at an optimal time slot in each read round. The primary advantage of our algorithm is the ability to achieve a good compromise between computation complexity and throughput performance. The results show that the proposed method provides up to 400 tags/s read speed and can obtain 5%-10% time-saving efficiency, as compared with typical dynamic framed-slotted ALOHA. © 1967-2012 IEEE. Source


Lin J.-W.,National Cheng Kung University
Journal of Earth System Science | Year: 2012

Principal Component Analysis (PCA) and image processing are used to determine Total Electron Content (TEC) anomalies in the F-layer of the ionosphere relating to Typhoon Nakri for 29 May, 2008 (UTC). PCA and image processing are applied to the global ionospheric map (GIM) with transforms conducted for the time period 12:00-14:00 UT on 29 May, 2008 when the wind was most intense. Results show that at a height of approximately 150-200 km the TEC anomaly is highly localized; however, it becomes more intense and widespread with height. Potential causes of these results are discussed with emphasis given to acoustic gravity waves caused by wind force. © Indian Academy of Sciences. Source


Saon G.,IBM | Chien J.-T.,National Cheng Kung University
IEEE Transactions on Audio, Speech and Language Processing | Year: 2012

In this paper, we introduce Bayesian sensing hidden Markov models (BS-HMMs) to represent sequential data based on a set of state-dependent basis vectors. The goal of this work is to perform Bayesian sensing and model regularization for heterogeneous training data. By incorporating a prior density on sensing weights, the relevance of different bases to a feature vector is determined by the corresponding precision parameters. The BS-HMM parameters, consisting of the basis vectors, the precision matrices of sensing weights and the precision matrices of reconstruction errors, are jointly estimated by maximizing the likelihood function, which is marginalized over the weight priors. We derive recursive solutions for the three parameters, which are expressed via maximum a posteriori estimates of the sensing weights. We specifically optimize BS-HMMs for large-vocabulary continuous speech recognition (LVCSR) by introducing a mixture model of BS-HMMs and by adapting the basis vectors to different speakers. Discriminative training of BS-HMMs in the model domain and the feature domain is also proposed. Experimental results on an LVCSR task show consistent improvements due to the three sets of BS-HMM parameters and demonstrate how the extensions of mixture models, speaker adaptation, and discriminative training achieve better recognition results compared to those of conventional HMMs based on Gaussian mixture models. © 2011 IEEE. Source


Wong T.-T.,National Cheng Kung University
Pattern Recognition | Year: 2015

Classification is an essential task for predicting the class values of new instances. Both k-fold and leave-one-out cross validation are very popular for evaluating the performance of classification algorithms. Many data mining literatures introduce the operations for these two kinds of cross validation and the statistical methods that can be used to analyze the resulting accuracies of algorithms, while those contents are generally not all consistent. Analysts can therefore be confused in performing a cross validation procedure. In this paper, the independence assumptions in cross validation are introduced, and the circumstances that satisfy the assumptions are also addressed. The independence assumptions are then used to derive the sampling distributions of the point estimators for k-fold and leave-one-out cross validation. The cross validation procedure to have such sampling distributions is discussed to provide new insights in evaluating the performance of classification algorithms. © 2015 Elsevier Ltd. Source


Huang C.-C.,National Cheng Kung University
Geomorphology | Year: 2013

Typhoon Morakot devastated Taiwan during August 6-11, 2009, with a maximum total rainfall of 2884. mm, causing >. 22,000 cases of slope failures. Rainfall thresholds for debris flow initiation are investigated using the hourly intensity vs. duration (. I-D), hourly intensity vs. cumulative rainfall (. I-R), and daily rainfall vs. antecedent daily rainfall (. ADR) index methods. Among the 39 well-documented cases, 32 sites with known date and time of debris flow initiation were focused. Results reveal that debris flows and debris avalanches occur under a very wide range of rainfall characteristics, with return periods ranging from several years to 200. years, indicating that the empirical rainfall threshold alone is insufficient for an effective debris flow prediction system. A consistent pattern of all I-R paths for the investigated sites shows the combined effect of rainfall characteristics and inherent stability features of the slopes, suggesting that the I-R path is potentially useful in facilitating debris flow predictions. It is also suggested that empirical rainfall thresholds should be calibrated using physical models against specific slope conditions to increase the accuracy of debris flow predictions. © 2012 Elsevier B.V. Source


Most research on the Illness Management and Recovery (IMR) program for people with severe mental illnesses has focused on individuals with stable symptoms living in the community, with less attention to persons being treated in an inpatient setting. We evaluated the feasibility and effects of an IMR program adapted for individuals with schizophrenia who were awaiting discharge into the community. A randomized controlled trial was conducted at 2 hospitals in Taiwan to compare the adapted IMR program with treatment as usual (TAU). Ninety-seven individuals with schizophrenia were randomized to the adapted IMR program or TAU. Four outcome indicators including illness-management knowledge, attitudes toward medication, insight, and symptoms were assessed at baseline, posttreatment, and at a 1-month follow-up following discharge from the hospital. Participants in the adapted IMR group showed significantly greater improvements at posttreatment and 1-month follow-up in illness-management knowledge, attitudes toward medication, insight, and negative symptoms on the Brief Psychiatric Rating Scale (BPRS) than individuals in the TAU group. There were no significant differences between the 2 groups on other subscales of the BPRS. This is the first controlled evaluation of a version of the IMR program in an East Asian culture, and the first to evaluate it in an acute care inpatient setting. Our findings support the feasibility and potential benefits of implementing an adapted IMR program, focused on the prevention of relapses and rehospitalizations, during the discharge period of an inpatient treatment stay to prepare individuals to reenter the community. PsycINFO Database Record (c) 2013 APA, all rights reserved. Source


Wang F.,National Cheng Kung University
Telemedicine and e-Health | Year: 2014

Objective: This research uses the quality-adjusted life expectancy (QALE) method to assess the QALE changes of rural residents before and after introducing telemedicine health services. Materials and Methods: Based on Taiwan's experiences of telemedicine provision over the period 1995-2004, this representative of a national sample is composed of 85 cases for people living in Penghu County, a remote area in Taiwan. Cases were evaluated using persons with life expectancy at birth from 85 to 0 years. Results: The provision of telemedicine health services increased rural population QALE by 2.91 quality-adjusted life years. Telemedicine provision does improve rural residents' health status. Relative to the index population living in Taipei, the capital of Taiwan, the survival ratios of the population of concern >65 years decreased faster and were less than those of the index population >65 years by at least 7% and 3%, respectively, before and after introducing telemedicine health services. Conclusions: It appears that the needs for telemedicine health services increased along with the aging of our society in rural and underserved regions. © Copyright 2014, Mary Ann Liebert, Inc. 2014. Source


Chen S.-Y.,National Cheng Kung University
Rheumatology International | Year: 2014

Increased expression of microRNA-223 (miR-223) has been demonstrated in rheumatoid arthritis (RA) patients. Two research teams focus recently on the underlying mechanisms mediated by miR-223 but two stories are developed in opposite ways. © 2013 Springer-Verlag Berlin Heidelberg. Source


Tang Y.-G.,Hwa Hsia University of Technology | Kung G.T.C.,National Cheng Kung University
Computers and Geotechnics | Year: 2010

In this study, a series of inverse-analysis numerical experiments was performed to investigate the effect of soil models on the deformations caused by excavation by using the finite element method. The nonlinear optimization technique that was incorporated into the finite element code was used for the inverse-analysis numerical experiments. Three soil models (the hyperbolic model, pseudo-plasticity model, and modified pseudo-plasticity model) were employed in the intended numerical experiments on a well-documented excavation case history. The results indicate that wall deflection due to excavation can be accurately back-figured by each of the three soil models, while the ground surface settlement can be reasonably optimized only by the pseudo-plasticity model and the modified pseudo-plasticity model. Importantly, the modified pseudo-plasticity model can yield more reasonable simulations when the wall deflection and the ground surface settlement are simultaneously back-figured. The results show that selection of an adequate soil model that is capable of adequately describing the stress-strain-strength characteristics of the soils is essentially crucial when predicting the excavation-induced ground response. © 2010 Elsevier Ltd. Source


Wang J.-Y.,National Cheng Kung University
Allergy, Asthma and Immunology Research | Year: 2013

Hypersensitivity to house dust mite (HDM; Dermatophagoides sp.) allergens is one of the most common allergic responses, affecting up to 85% of asthmatics. Sensitization to indoor allergens is the strongest independent risk factor associated with asthma. Additionally, >50% of children and adolescents with asthma are sensitized to HDM. Although allergen-specific CD4+ Th2 cells orchestrate the HDM allergic response through induction of IgE directed toward mite allergens, activation of innate immunity also plays a critical role in HDM-induced allergic inflammation. This review highlights the HDM components that lead to activation of the innate immune response. Activation may due to HDM proteases. Proteases may be recognized by protease-activation receptors (PARs), Toll-like receptors (TLRs), or C-type lectin receptors (CTRs), or act as a molecular mimic for PAMP activation signaling pathways. Understanding the role of mite allergen-induced innate immunity will facilitate the development of therapeutic strategies that exploit innate immunity receptors and associated signaling pathways for the treatment of allergic asthma. © The Korean Academy of Asthma, Allergy and Clinical Immunology. Source


Lee C.-T.,National Cheng Kung University
Materials | Year: 2010

Zinc oxide (ZnO) is a potential candidate material for optoelectronic applications, especially for blue to ultraviolet light emitting devices, due to its fundamental advantages, such as direct wide band gap of 3.37 eV, large exciton binding energy of 60 meV, and high optical gain of 320 cm-1 at room temperature. Its luminescent properties have been intensively investigated for samples, in the form of bulk, thin film, or nanostructure, prepared by various methods and doped with different impurities. In this paper, we first review briefly the recent progress in this field. Then a comprehensive summary of the research carried out in our laboratory on ZnO preparation and its luminescent properties, will be presented, in which the involved samples include ZnO films and nanorods prepared with different methods and doped with n-type or p-type impurities. The results of ZnO based LEDs will also be discussed. © 2010 by the authors. Source


Social participation is an important strategy in promoting successful aging. Although participating in volunteering has been proven to benefit older adults’ health and well-being, we often ignore its role as a process of learning while helping others. The purpose of this study was to use the self-defined successful aging concept of seniors to explore the roles of learning through volunteering in Taiwan, an Asian country with a dramatically fast growth of its older population. Using in-depth interviews of 31 older adults who fit the participation criteria, this study concluded that learning through volunteering, a form of informal learning, is a holistic approach to successful aging, including physical, psychological, social, and spiritual dimensions. Through the learning, volunteering benefited the volunteers’ self-defined successful aging by (a) establishing a substantial and expanding life, (b) building and improving relationships, (c) enhancing positive changes and self-evaluation, (d) promoting physical and psychological health, and (e) triggering treasures and preparations for the rest of life. The five dimensions can work alone but often interactively facilitate the seniors’ successful aging. These findings enrich the existing body of knowledge by revealing the dynamic between learning through volunteering and self-defined successful aging in Taiwan. Policy makers and practitioners might use these findings to popularize elder volunteerism and other forms of elder learning activities that will then better equip older adults to fulfill their desire for a successful old age. © 2016 Taylor & Francis. Source


Shiah Y.C.,National Cheng Kung University
International Journal of Solids and Structures | Year: 2016

In this article, stress concentrations around cavities in 3D generally anisotropic bodies are investigated using the boundary element method (BEM), where the associated volume integral is analytically transformed to the boundary. All derivations are based upon the Fourier-series representations of the fundamental solutions, including Green's function of displacements and its derivatives. This approach of analytical transformation has fully restored the BEM's distinctive notion that only the boundary needs to be discretized. The goal of the present work is to investigate the thermoelastic stress-concentration around cavities in 3D anisotropic bodies by use of the analytically transformed boundary integral equation (BIE). The work has fully recovered the BEM's nature of boundary discretization for treating 3D generally anisotropic thermoelasticity. This is the first implemented work that successfully treats thermoelastic problems for 3D generally anisotropic solids by the analytically transformed BIE. In the paper, Interesting phenomena are observed from the analyses of stress concentrations around oblate cavities and some discussions are made. © 2015 Elsevier Ltd. All rights reserved. Source


Hsin Chang H.,National Cheng Kung University
International Journal of Human Computer Studies | Year: 2010

Word Wide Web intelligent agent technology has provided researchers and practitioners, such as those involved in information technology, innovation, knowledge management, and technical collaboration with the ability to examine the design principles and performance characteristics of the various approaches to intelligent agent technology, and to increase the cross fertilization of ideas on the development of autonomous agents and multi-agent systems among different domains. This study investigates the employment of intelligent agents in a web-based auction process, with particular reference to the appropriateness of the agent software for the online auction task, consumers' value perception of the agent, the effect of this consumer perception on their intention to use the tool, and a measure of consumer acceptance. In the initial case study, both consumers and web operators thought the use of software agents enhanced online auction efficiency and timeliness. The second phase of the investigation established that consumer familiarity with the agent functionality was positively associated with seven dimensions: online auction site's task, agent's technology, task-technology fit, perceived ease of use, perceived usefulness, perceived playfulness, intention to use tool, and negatively associated with perceived risk. Intelligent agents have the potential to release skilled operator time for the use of value-adding tasks in the planning and expansion of online auctions. © 2009 Elsevier Ltd. All rights reserved. Source


Wang C.K.,National Cheng Kung University
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2012

Full waveform data recording the reflected laser signal from ground objects have been provided by some commercial airborne LIDAR systems in the last few years. Waveform data enable users to explore more information and characteristics of the earth surface than conventional LIDAR point cloud. An important application is to extract extra point clouds from waveform data in addition to the point cloud generated by the online process of echo detection. Some difficult-to-detect points, which may be important to topographic mapping, can be rediscovered from waveform data. The motivation of this study is to explore weak and overlapped returns of a waveform. This paper presents a wavelet-based echo detection algorithm, which is compared with the zero-crossing detection method for evaluation. Some simulated waveforms deteriorated with different noises are made to test the limitations of the detector. The experimental results show that the wavelet-based detector outperformed the zero-crossing detector in both difficult-to-detect cases. The detector is also applied to a real waveform dataset. In addition to the total number of echoes provided by the instrument, the detector found 18% more of echoes. The proposed detector is significant in finding weak and overlapped returns from waveforms. Source


Hwu C.,National Cheng Kung University
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences | Year: 2010

The boundary integral equations for the stretching-bending coupling analysis of general laminated plates are derived in this paper with the aid of the reciprocal theorem of Betti and Raleigh. No restriction is placed on the location of the point load or moment, and so it can be an internal or external point or a smooth or non-smooth boundary point. The fundamental solutions derived from Green's function for an infinite laminated plate subjected to concentrated forces/moments are presented in the complex matrix form. Through the use of some identities converting complex form to real form, the free term coefficients, which are important for the boundary integral equations, are obtained explicitly and expressed in the real form. Alternative formulae for calculating the free term coefficients are also derived using five rigid body movements. By using the explicit real expressions obtained recently for the Stroh-like formalism of coupled stretching-bending analysis, the free term coefficients are further reduced to the cases of isotropic plates and are then compared with known expressions published in the literature. Since stretching and bending decouple for isotropic plates, comparison is made separately for the in-plane problem and plate bending problem, and it is shown that the boundary integral equations derived in this paper agree with previous results for these two special cases. © 2010 The Royal Society. Source


Liu K.-C.,Far East University of Taiwan | Chen H.-T.,National Cheng Kung University
International Journal of Thermal Sciences | Year: 2010

The success of hyperthermia treatment depends on the precise prediction and control of temperature distribution in the tissue. It was absolutely a necessity for hyperthermia treatment planning to understand the heat transport occurring in biological tissue. The tissue is highly non-homogenous, and non-Fourier thermal behavior in biological tissue has been experimentally observed. The dual phase lag model of heat conduction has been used to interpret the non-Fourier thermal behavior. This work attempts to be an extension study of Antaki [12] and explore whether the DPL thermal behavior exists in tissue. The inverse non-Fourier bio-heat transfer problem in the bi-layer spherical geometry is analyzed. In order to further address whether the dual phase lag model of bio-heat transfer merits additional study, the comparisons of the history of temperature increase among the present calculated results, the calculated values from the classical bio-heat transfer equation, and the experimental data are made for various measurement locations. © 2010 Elsevier Masson SAS. All rights reserved. Source


Chen Y.H.,National Cheng Kung University
Journal of Non-Crystalline Solids | Year: 2011

FeTiO3 nanoparticles (nano-FeTiO3 or nano-ilmenite) can be synthesized by the sol-gel method. In this study, the physical properties and dye adsorption characteristics of nano-FeTiO3 are investigated. A synthesized nano-ilmenite has a particle size of approximately 20 to 60 nm with a polycrystalline structure. The FeTiO3 nanoparticles exhibit weak ferromagnetism and show high adsorption capacity for methylene blue. Experimental data are fitted to pseudo-first-order and pseudo-second-order equations; the pseudo-first-order model is found to be more suitable. It also suggests that the Langmuir isotherm is more adequate than the Freundlich isotherm in simulating the adsorption isotherm of organic dye. The maximum adsorption capacity is 71.9 mg/g, therefore, the magnetic FeTiO3 nanoparticles show a considerably high adsorption capacity for organic dyes in a solution. These findings indicate that the nano-ilmenite is an effective material for dye removal and can be used to alleviate environmental problems. © 2010 Elsevier B.V. All rights reserved. Source


Lin C.L.,National Cheng Kung University
Journal of orthopaedic research : official publication of the Orthopaedic Research Society | Year: 2012

Suture anchors and screws are commonly used for fixation of humeral greater tuberosity (GT) fractures in either arthroscopic or open surgeries, but no biomechanical studies have been performed to compare the strength of fixation constructs using these two implants. This cadaveric study aimed to compare the biomechanical strength of three different fixation constructs in the management of GT fractures: Double-Row Suture Anchor Fixation (DR); Suture-Bridge Technique using suture anchors and knotless suture anchors (SB); and Two-Screw Fixation (TS). The experimental procedure was designed to assess fracture displacement after cyclic loading, failure load, and failure mode of the fixation construct. Significant differences were found among the SB (321 N), DR (263 N), and TS (187 N) groups (SB > DR > TS, p < 0.05) in the mean force of cyclic loading to create 3 mm displacement. Regarding the mean force of cyclic loading to create 5 mm displacement and ultimate failure load, no significant difference was found between the DR (370 N, 480 N) and SB (399 N, 493 N) groups, but both groups achieved superior results compared with the TS group (249 N, 340 N) (p < 0.05). The results suggested that the suture anchor constructs would be stronger than the fixation construct using screws for the humeral GT fracture. Copyright © 2011 Orthopaedic Research Society. Source


Chen T.,National Cheng Kung University
Mechanics Research Communications | Year: 2011

A novel class of graded cylinders is proposed as neutral inclusions inside host shafts of arbitrary cross-section under Saint-Venant's torsion. The graded cylinder is made of cylindrically orthotropic materials with position varying quantities. The profiles of the two distinct shear moduli in the radial and tangential directions follow specific forms based on an arbitrarily selected function along the radial distance. We show that this type of graded cylinders can serve as universal neutral inclusions within host shafts of arbitrary cross-sections. In addition, we find that the associated warping fields can be exactly determined in terms of simple exponents of the selected function. This suggests that, by tuning the gradation parameter, one can manipulate the warping field of the inserted cylinder without disturbing the fields inside the host shaft. This finding is an original contribution to the existing solvable configurations of composite shafts under torsion. © 2010 Elsevier Ltd All rights reserved. Source


Cheng C.,National Cheng Kung University
Journal of Magnetism and Magnetic Materials | Year: 2013

Recent advances on nanometer films observed magnetization enhanced NiFe 2O 4 (NFO) in insulating phase as well as in conductive state with highly spin-polarized current which together can be integrated for potential applications in spintronics. In this brief report, we demonstrate, using density-functional-based calculations, how various cation distributions and magnetic orders can lead to a quadruple enhanced magnetization in NFO and the possible tuning of their electronic properties. The ground-state phase was identified as a structure having a tetragonal symmetry space group of P4 322 which is consistent with the most recent experimental conclusion. The energetically most likely phase exhibiting enhanced magnetization is an insulating inverse spinel phase while the experimentally observed conductive phase likely originates from a phase with cation inversion. © 2012 Elsevier B.V. All rights reserved. Source


Hempel M.,RWTH Aachen | Nezich D.,Massachusetts Institute of Technology | Kong J.,Massachusetts Institute of Technology | Hofmann M.,National Cheng Kung University
Nano Letters | Year: 2012

Here we report on the fabrication and characterization of a novel type of strain gauge based on percolative networks of 2D materials. The high sensitivity of the percolative carrier transport to strain induced morphology changes was exploited in strain sensors that can be produced from a wide variety of materials. Highly reliable and sensitive graphene-based thin film strain gauges were produced from solution processed graphene flakes by spray deposition. Control of the gauge sensitivity could be exerted through deposition-induced changes to the film morphology. This exceptional property was explained through modeling of the strain induced changes to the flake-flake overlap for different percolation networks. The ability to directly deposit strain gauges on complex-shaped and transparent surfaces was presented. The demonstrated scalable fabrication, superior sensitivity over conventional sensors, and unique properties of the described strain gauges have the potential to improve existing technology and open up new fields of applications for strain sensors. © 2012 American Chemical Society. Source


Jeng D.J.-F.,National Cheng Kung University
International Journal of Innovative Computing, Information and Control | Year: 2012

Service operation strategy has been widely adopted by firms who wish to enhance their competitive advantage to be better prepared to face external challenges. Previous studies have shown that internal service quality (ISQ) ultimately drives the profit of enterprises. This research has thus chosen ISQ as the focus for the development of an assessment model to reform organizations that undertake ISQ to enhance their core competencies. This paper describes a fuzzy hierarchical analytic approach to determine the weighting of subjective judgments and presents a nonadditive fuzzy integral technique to evaluate an ISQ case as a fuzzy multiple criteria decision-making (MCDM) problem. Through literature reviews and experts interviews, 26 criteria are generated along with nine dimensions and five strategy alternatives. By ranking fuzzy weights and fuzzy synthetic utility values, the relative importance of criteria and the best strategies can be determined. An empirical case of ISQ improvement strategy for a Taiwanese semiconductor manufacturer is demonstrated to show the effectiveness of the proposed methods when dealing with criteria that are not independent. The empirical results show that employee rewards and recognition outrank other strategies with regard to improving the ISQ. These results will not only help organizations that aim to improve their internal service operations, but can also assist human resource professionals in more effectively monitoring and improving the performance of employees. © 2012 ICIC International. Source


Kuo Y.-S.,National Cheng Kung University | Achmus M.,Leibniz University of Hanover | Abdel-Rahman K.,Leibniz University of Hanover
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2012

Monopiles are used as foundation structures for offshore wind energy towers. To ensure stable behavior of the monopile under cyclic loading conditions, a minimum embedded length is usually required. For this, different design criteria are used, some of which result in very large embedded depths for large-diameter monopiles. The suitability of these criteria is tested by means of numerical simulations. To account for cyclic loading, a new approach called the stiffness degradation method is applied. The results of a parametric study show that the design criteria used can indeed ensure optimum pile performance under static and cyclic loads. It is recommended that the requirement of a critical pile length, which leads to the minimum pile deflection under extreme load, is used as a design criterion. For the cases considered, this requirement results in only slightly greater cyclic deformations compared to the optimum case of very long piles. A further optimization of the required monopile length with respect to cyclic loading is possible, but requires specific consideration of cyclic behavior, as is done in this paper. © 2012 American Society of Civil Engineers. Source


Yang C.-D.,National Cheng Kung University
International Journal of Nonlinear Sciences and Numerical Simulation | Year: 2010

Mathematically, the philosophy of Tai Chi advocates that the nature (the Tao) is a complex-valued world containing two parts: yang is the observable (real) part and yin is the unobservable (imaginary) part. What we have sensed and measured is only the real part of the world, which is the physical world that we experience in daily life. However, this Yin-Yang concept has remained an issue of pure philosophy for a very long time; no mathematical or physical principles had ever been developed exclusively for Yin-Yang theory to justify its scientific truth. The proposed complex-valued mechanics is the first scientific realization of the Yin-Yang theory following the same kind of philosophy that physical phenomena happen in complex space and what we customarily consider as the physical reality is merely the projections of the physical phenomena into the real space. Complex mechanics successfully demonstrates the evolution of a physical phenomenon in the complex space and verifies the consistence of its projection into the real space with the measurement data. The aim of this paper is to introduce complex mechanics as a bridge between Yin-Yang theory and quantum mechanics by pointing out that the unique features of quantum motions, such as tunneling, spin, quantization, uncertainty principle, multiple paths and wave-particle duality, all originate from the Yin-Yang entanglement, i.e., the interaction between real and imaginary motions in complex space. ©Freund Publishing House Ltd. Source


Chu C.-S.,Ming Chi University of Technology | Lo Y.-L.,National Cheng Kung University
Sensors and Actuators, B: Chemical | Year: 2011

A simple, low-cost technique for fabrication of high performance optical fiber oxygen sensor is described. An organically modified silicate (ORMOSIL) as a matrix for the fabrication of oxygen sensing film was produced. The technique is based on coating the end of an optical fiber with ORMOSIL composite xerogel films film sequestered with luminophore platinum (II) meso- tetrakis(pentafluorophenyl)porphyrin (PtTFPP) prepared by a sol-gel process. The composite xerogels studied are 3,3,3-trifluoropropyltrimethoxysliane (TFP-TriMOS) or n-propyltrimethoxysilane (n-propyl-TriMOS)/tetraethylorthosilane (TEOS)/n-octyltriethoxysilane (Octyl-triEOS). Results show that, expect for PtTFPP-doped TFP-TriMOS or n-propyl-TriMOS/TEOS/Octyl-triEOS composite xerogels show the high sensitivity and linear Stern-Volmer relationship which indicate the homogenous environment of the luminophore. The sensitivities of the two oxygen sensors are quantified in terms of the ratio IN2/I O2, where IN2 and IO2 represent the detected fluorescence intensities in pure nitrogen and pure oxygen environments, respectively. The experimental results reveal that the PtTFPP-doped TFP-TriMOS/TEOS/Octyl-triEOS and n-propyl-TriMOS/TEOS/Octyl-triEOS oxygen sensors have sensitivities of 101 and 155, respectively. The experimental results confirm that the current oxygen sensors exhibit the linear Stern-Volmer plots and high-sensitive based on the oxygen indicator embedded in TFP-TriMOS or n-propyl-TriMOS/TEOS/Octyl-triEOS composite xerogels. Crown Copyright © 2010 Published by Elsevier B.V. All rights reserved. Source


Ju S.H.,National Cheng Kung University
Nonlinear Dynamics | Year: 2012

This paper investigates the derailment of high-speed trains moving on multispan simply supported bridges. A moving wheel finite element containing contact and separation modes was developed to simulate vehicle-bridge interaction problems under seismic loads. Rail irregularities and bridge-rail-train interactions were appropriately considered in the nonlinear finite element analysis, which indicates that the derailment coefficients are enlarged with the increase of train speeds for high-speed trains moving on multispan simply supported bridges. The accelerations of elevated bridge girders may be significantly magnified during the seismic load; moreover, gaps between simply supported girders during seismic loads will produce large derailment coefficients. © 2011 Springer Science+Business Media B.V. Source


Yu F.-Y.,National Cheng Kung University
Educational Technology and Society | Year: 2012

This study examined the effects of different levels of identity revelation in relation to aspects most relevant to engaged online learning activities. An online learning system supporting question-generation and peer-assessment was adopted. Three 7 th grade classes (N=101) were assigned to three identity revelation modes (real-name, nickname and anonymity) and observed for six weeks. A pretest-posttest quasi-experimental research design was adopted. Findings did not confirm that different levels of identity revelation affected participants' academic performance, nor led participants to view the peer-assessment strategy, the interacting parties, interaction processes, or engaged activities in different ways. Implications for generalizability of research findings and suggestions for teaching practices are offered. © International Forum of Educational Technology & Society (IFETS). Source


Hwu C.,National Cheng Kung University
International Journal of Fracture | Year: 2012

In this paper, the stresses near the tip of interface corners are expressed in matrix power function form. To make this matrix power function form valid for all possible cases of interface corners, all kinds of singularities including oscillatory and logarithmic singularity are discussed in this paper. The coefficient vector of this matrix power function form solution is then defined as a vector of stress intensity factors along the radial direction. Since the stress intensity factors are functions of radial direction, themaximum stress intensity factor of a certain radial directionmay be useful for the fracture prediction of interface corners. This new definition of stress intensity factors is applicable for all possible singular orders-repeated or distinct, real or complex, and keeps the same unit for all possible interface corners. Therefore, it will be helpful for bridging the problems of cracks, corners, interface cracks and interface corners. Finally, the matrix form solutions are reduced to the scalar form solutions for two special cases. One is a special case of corner angles-cracks, and the other is a special case of anisotropic materials-isotropic materials. Through this reduction, new scalar form analytical solutions are obtained and specialized further to compare with the existing analytical solutions. C. Hwu (B) Institute of Aeronautics and Astronautics, National Cheng Kung University, Tainan, Taiwan, R.O.C. © Springer Science+Business Media B.V. 2012. Source


Cadmium Tellurium (CdTe) nanorods were successfully synthesized by a novel soft-chemical solvothermal method with ethylenediamine template. The ethylenediamine plays a critical role in the formation of CdTe nanocrystals. Single-crystalline CdTe with rod-like and flower-like morphologies has been successfully synthesized at 120 °C for 4 h. The prepared nanorods have cubic characteristics with a diameter of about 60 nm and a length of up to several micrometers. The nanorod exhibits a concentration tunable photoluminescence and a narrow full width at half-maximum (FWHM) value of PL spectra can be obtained, which may be useful for developing solar cell devices or LED, chemical sensors or in optical device. Based on a series of comparative experiments under different reaction conditions, the probable formation mechanism and photoluminescence emission of CdTe nanocrystals are proposed. © 2013 Elsevier B.V. All rights reserved. Source


Sun C.-H.,National Cheng Kung University
Annals of Regional Science | Year: 2012

This paper expands Lai's (Reg Sci Urban Econ 31:535-546, 2001) directional market analysis to a three-player game and endogenizes a restricted assumption of Lai (Reg Sci Urban Econ 31:535-546, 2001) through the test of a validated equilibrium introduced by Spagat (Math Soc Sci 24:49-57, 1992) and the use of lexicographic preference relation players (with payoff ranking a secondary consideration after the game's payoff). There are multiple equilibrium outcomes, and any player may take advantage in this game due to the indifference problem of the players. However, if we utilize the validated equilibrium refinement, then the results present that the later the players enter a directional market, the greater the benefits they receive. If a player's preference relation is lexicographic ordering, then we obtain results identical to the validated equilibrium outcomes. This paper ends with an extension of a general number of players. © 2010 Springer-Verlag. Source


Liu Y.-C.,National Cheng Kung University | Chopra N.,University of Maryland University College
IEEE Transactions on Control Systems Technology | Year: 2014

Input/output (I/O) delays in a closed-loop robotic system can significantly deteriorate both its stability and performance. In this paper, we study the position control problem for robotic manipulators under I/O delays, where the delays manifest as a result of communication with a non-collocated controller. Previous research on this topic has assumed the gravitational torque to be pre-compensated in a collocated manner. This paper studies the stability and regulation performance of the closed-loop system when the compensation for the gravitational torque is provided by a non-collocated controller. We demonstrate that simply utilizing scattering transformation for robotic systems under I/O communication delays results in position drift due to gravity compensation. Hence, a new control algorithm incorporating delayed position feedback and scattering variables is studied subsequently. Stability and performance margins dependent on the round-trip delays and the gravitational model are proposed to guarantee stable position regulation. Since the control architecture with scattering transformation does not address the stability problem due to sensing-actuation delays, a new controller is developed to cope with robotic control systems under time-varying sensing-actuation delays. The proposed control algorithms are studied in this paper via experiments on a manipulator with three degrees of freedom. © 2014 IEEE. Source


Lin P.D.,National Cheng Kung University | Tsai C.-Y.,National formosa University
Journal of the Optical Society of America A: Optics and Image Science, and Vision | Year: 2012

Snell's law describes the relationship between the incidence angle and reflection (or refraction) angle of a light ray impinging on the interface between two different isotropic media. In this paper, Snell's law is used to derive the unit normal vectors of an aspherical surface given a knowledge of the unit directional vectors of the incoming and outgoing rays. The proposed method has important applications in the design and fabrication of aspherical surfaces since the surface normal vectors determine not only the optical performance of the surface but also the cutting tool angles required to machine the surfaces. © 2012 Optical Society of America. Source


Wu S.-H.,National Taiwan University | Mou C.-Y.,National Taiwan University | Lin H.-P.,National Cheng Kung University
Chemical Society Reviews | Year: 2013

Good control of the morphology, particle size, uniformity and dispersity of mesoporous silica nanoparticles (MSNs) is of increasing importance to their use in catalyst, adsorption, polymer filler, optical devices, bio-imaging, drug delivery, and biomedical applications. This review discusses different synthesis methodologies to prepare well-dispersed MSNs and hollow silica nanoparticles (HSNs) with tunable dimensions ranging from a few to hundreds of nanometers of different mesostructures. The methods include fast self-assembly, soft and hard templating, a modified Stöber method, dissolving-reconstruction and modified aerogel approaches. In practical applications, the MSNs prepared by these methods demonstrate good potential for use in high-performance catalysis, antireflection coating, transparent polymer-MSNs nanocomposites, drug-release and theranostic systems. © The Royal Society of Chemistry 2013. Source


Hwu C.,National Cheng Kung University
Engineering Analysis with Boundary Elements | Year: 2012

The boundary integral equations for the coupled stretching-bending analysis of thin laminated plates involve an integral which will be singular when the field point approaches the source point. To avoid the singular problem occurring in the numerical programming, the boundary integral equations are modified in which the integrals of singular part are integrated analytically. The analytical solutions for the free term coefficients and singular integrals are obtained in explicit closed-form. By dividing the boundary into elements and using suitable interpolation polynomials for basic functions, the set of equations necessary for boundary element programming are written explicitly for regular nodes and corner nodes. The equations for the determination of displacements and stresses at internal points are also presented in this paper. © 2012 Elsevier Ltd. All rights reserved. Source


Du S.-W.,China Steel Corporation | Chen W.-H.,National Cheng Kung University | Lucas J.A.,University of Newcastle
Bioresource Technology | Year: 2014

To evaluate the utility potential of pretreated biomass in blast furnaces, the fuel properties, including fuel ratio, ignition temperature, and burnout, of bamboo, oil palm, rice husk, sugarcane bagasse, and Madagascar almond undergoing torrefaction and carbonization in a rotary furnace are analyzed and compared to those of a high-volatile coal and a low-volatile one used in pulverized coal injection (PCI). The energy densities of bamboo and Madagascar almond are improved drastically from carbonization, whereas the increase in the calorific value of rice husk from the pretreatment is not obvious. Intensifying pretreatment extent significantly increases the fuel ratio and ignition temperature of biomass, but decreases burnout. The fuel properties of pretreated biomass materials are superior to those of the low-volatile coal. For biomass torrefied at 300. °C or carbonized at temperatures below 500. °C, the pretreated biomass can be blended with coals for PCI. © 2014 Elsevier Ltd. Source


Hsieh M.-L.,National Cheng Kung University | Chyi S.-J.,National Kaohsiung Normal University
Quaternary Science Reviews | Year: 2010

Development of fan terraces in incision-dominated river settings documents episodic increases of sediment supply from upland catchments. In the non-glaciated, active mountains of Taiwan, such increases in sediment supply result typically from increases in landslide/debris flow activity. Studying fan terraces, therefore, helps understand the history and nature of mass-wasting processes eroding the mountains. This study explores fan-terrace successions developed at tributary mouths of the Chen-yeo-lan and Lao-nung Rivers in central-southern Taiwan. Judging from the spatial variations of sizes, heights, sequences and sedimentation of the fan terraces, the magnitude and frequency of mass-wasting activities appear to vary from tributary catchment to catchment. Two types of tributary catchment are differentiated, which can be located in close proximity to each other. One has been subject to extremely large but infrequent mass-wasting events, as a result of which high and/or large fan terraces with 100-200 m thick debris-flow/fluvial gravels have been formed. Seven examples of this type of fan terrace have yielded radiocarbon dates of >40. ka, ~18.4. ka, ~13.9. ka, 8.9-9.5. ka, 3.9-4.8. ka, ~3.3. ka, and ~1.4. ka in age. With the availability of multiple dates, this type of fan terrace can be shown to have been created in no more than 1000 years, from the aggradation of thick gravel sequences to subsequent incision. The second type of catchment has been subject to relatively minor but frequent mass-wasting events. Due to repeated incision after each such event, the resultant fan terraces are relatively low and limited in size but have formed over lengthy periods. Although located in the same geological and geomorphic setting, the dated fan-forming mass-wasting events in the Chen-yeo-lan catchment do not appear to have occurred synchronously with those in the Lao-nung catchment. Nor could the succession of these events, or their origins, be clearly linked to known paleo-climate data. These findings highlight the importance of internal factors (e.g., rock-mass strength) in determining the timing, magnitude, and frequency of mass-wasting events in the studied mountains, which are subject to active rock uplift, highly active seismicity, and intense rainfall. © 2009 Elsevier Ltd. Source


This longitudinal study aimed to investigate the associations between the polymorphisms of guanine nucleotide-binding protein subunit β-3 (GNB3) C825T and metabolic disturbance in bipolar II disorder (BP-II) patients being treated with valproate (VPA). A 100 BP-II patients received a 12-week course of VPA treatment, and their body weight and metabolic indices were measured. At baseline, the GNB3 C825T polymorphisms were associated with the triglyceride level (P=0.032) in BP-II patients. During the VPA treatment course, the polymorphisms were not only associated with body mass index (BMI) and waist circumference (P-values=0.009 and 0.001, respectively), but also with total cholesterol, triglyceride, low-density lipoprotein and leptin levels (P-values=0.004, 0.002, 0.031 and 0.015, respectively). Patients with the TT genotype had a lower BMI, smaller waist circumference, and lower levels of lipids and leptin than those with the CT or CC genotypes undergoing the VPA treatment course.The Pharmacogenomics Journal advance online publication, 9 February 2016; doi:10.1038/tpj.2015.96. © 2016 Macmillan Publishers Limited Source


A computational scheme based on differential geometry was proposed in a previous study [Appl. Opt. 52, 4151 (2013)] for determining the first- and second-order derivative matrices of a skew ray reflected/ refracted at a flat boundary surface. The present study extends this methodology to the case of a skew ray reflected/refracted at a spherical boundary surface. The validity of the proposed approach is demonstrated using two retro-reflectors for illustration purposes. The results show that the proposed method provides an effective means of determining the search direction required to minimize the merit function during the optimization stage of the optical system design process. © 2013 Optical Society of America. Source


Huang W.-H.,National Cheng Kung University
International Journal of Modern Physics A | Year: 2013

We use the matching method to investigate the first-order phase transition in holographic superconductor and superfluid. We first use the simple holographic superconductor model to describe the matching method and mention how to see the first-order phase transition. Next, we study the holographic superconductor with Stückelberg term and see that the analytic results indicate the existence of first-order phase transition. Finally, we study the holographic superfluid and show that the first-order phase transition can be found for some values of parameters. We determine the critical value analytically and compare it with the previous numerical result. © 2013 World Scientific Publishing Company. Source


Huang C.-C.,National Cheng Kung University
Geosynthetics International | Year: 2016

The effects of soil saturation on the ultimate bearing capacity characteristics of reinforced and unreinforced horizontal sandy ground were investigated using a 100-mm-wide rigid strip footing. The test results revealed that saturation of the soil influenced the ultimate bearing capacity characteristics of unreinforced and reinforced ground in two ways: a reduced effective self-weight of the soil and an apparent cohesion induced by negative excess pore pressures. Ground saturation had a major influence on the footing settlement at peak footing load (Sp) partially due to the existence of negative excess pore water pressures. Values of Sp for the saturated ground were 100–200% larger than those for the dry one, regardless of the reinforcement state. For both saturated and dry reinforced ground, the moment of peak footing loadwas consistent with that of the maximum reinforcement force, revealing the effectiveness of geosynthetic reinforcement for enhancing the ultimate bearing capacity of the footing. An equation extended from that proposed in an earlier publication by the author and a colleague was used to simulate the effects of reinforcement and apparent cohesion of the saturated ground. The calculated values of bearing capacity ratio agreed well with the measured values. © 2015 Thomas Telford Ltd. Source


A computational scheme based on differential geometry is proposed for determining the first- and secondorder derivative matrices of a skew ray as it is reflected/refracted at a flat boundary surface. In the proposed approach, the position and orientation of the boundary surface in 3D space are described using just four variables. As a result, the proposed method is more computationally efficient than existing schemes based on all six variables. The derivative matrices enable the cross-coupling effects of the system variables on the exit ray to be fully understood. Furthermore, the proposed method provides a convenient means of determining the search direction used by existing gradient-based schemes to minimize the merit function during the optimization stage of the optical system design process. The validity of the proposed approach as an analysis and design tool is demonstrated using a corner-cube mirror and laser tracking system for illustration purposes. © 2013 Optical Society of America. Source


To evaluate the merit function of an optical system, it is necessary to determine the first- and secondorder derivative matrices of the boundary variable vector with respect to the system variable vector. Accordingly, the present study proposes a computationally efficient method for determining both matrices for optical systems containing only flat boundary surfaces. The validity of the proposed method is demonstrated by means of two illustrative prism design problems. In general, the results show that the proposed method can provide efficient search directions in many gradient-based optical design optimization methods. © 2013 Optical Society of America. Source


Chin W.-L.,National Cheng Kung University
Journal of Lightwave Technology | Year: 2013

This work introduces a novel symbol time synchronization method for optical fast orthogonal frequency-division multiplexing (FOFDM) systems. The first arrival path of a channel is well known to be related to the best symbol time; however, few approaches exploit this fact. In contrast, the basic idea of this study is to derive an estimate of channel-coefficient power using the periodic property of the discrete cosine transform (DCT) in FOFDM. The proposed method maximizes the effective signal power (ESP), which is defined as the signal power excluding the intersymbol interference (ISI), within the DCT window using the obtained channel-coefficient power. Simulations reveal that the proposed estimator exhibits low complexity and robustness against the presence of chromatic dispersion (CD). © 1983-2012 IEEE. Source


Hu H.-C.,Academia Sinica, Taiwan | Li H.-N.,Academia Sinica, Taiwan | Li H.-N.,National Cheng Kung University | Li H.-N.,National Tsing Hua University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

We calculate the time-like pion-photon transition form factor and the pion electromagnetic form factor up to next-to-leading order (NLO) of the strong coupling constant in the leading-twist kT factorization formalism. It is found that the NLO corrections to the magnitude (phase) are lower than 30% (30°) for the former, and lower than 25% (10°) for the latter at large invariant mass squared Q2>30GeV2 of the virtual photons. The increase of the strong phases with Q2 is obtained, consistent with the tendency indicated by experimental data. This behavior is attributed to the inclusion of parton transverse momenta kT, implying that the kT factorization is an appropriate framework for analyzing complex time-like form factors. Potential extensions of our formalism to two-body and three-body hadronic B meson decays are pointed out. © 2012 Elsevier B.V. Source


Cheng S.-J.,Academia Sinica, Taiwan | Lam N.,National Cheng Kung University
Communications in Mathematical Physics | Year: 2010

We develop a new method to solve the irreducible character problem for a wide class of modules over the general linear superalgebra, including all the finite-dimensional modules, by directly relating the problem to the classical Kazhdan-Lusztig theory. Furthermore, we prove that certain parabolic BGG categories over the general linear algebra and over the general linear superalgebra are equivalent. We also verify a parabolic version of a conjecture of Brundan on the irreducible characters in the BGG category of the general linear superalgebra. © 2010 Springer-Verlag. Source


Colon cancer is the third leading cause of death from cancer worldwide with less than 10% survival rate at the late stage. Although mutations of certain genes have been implicated in familial colon cancer development, the etiology of the majority of colon cancer remains unknown. Herein, we identified TYRO3 as a potential oncogene. Immunohistochemical staining results demonstrated that levels of TYRO3 were markedly elevated in polyps and colon cancer cells and were negatively correlated with prognosis. Overexpression of TYRO3 enhanced cell motility, invasion, anchorage-independent growth and metastatic ability, while knockdown of TYRO3 impaired all these processes. Results from meta-analysis showed that TYRO3 was associated with epithelial–mesenchymal transition (EMT) signatures. Gain-of-function and loss-of-function experiments demonstrated that expression of SNAI1, the master regulator of EMT, was regulated by TYRO3 and played a major role in mediating TYRO3-induced EMT processes. The murine model also demonstrated that Tyro3 and Snai1 were upregulated in the early stage of colon cancer development. To provide a proof-of-concept that TYRO3 is a druggable target in colon cancer therapy, we raised anti-TYRO3 human antibodies and showed that treatment with the human antibody abolished TYRO3-induced EMT process. More importantly, administration of this anti-TYRO3 antibody increased drug sensitivity in primary cultured colon cancer cells and xenografted mouse tumors. These findings demonstrate that TYRO3 is a novel oncogene and a druggable target in colon cancer.Oncogene advance online publication, 2 May 2016; doi:10.1038/onc.2016.120. © 2016 Macmillan Publishers Limited Source


Kang P.,Cornell University | Serey X.,Cornell University | Chen Y.-F.,National Cheng Kung University | Erickson D.,Cornell University
Nano Letters | Year: 2012

Near-field optical techniques have enabled the trapping, transport, and handling of nanoscopic materials much smaller than what can be manipulated with traditional optical tweezers. Here we extend the scope of what is possible by demonstrating angular orientation and rotational control of both biological and nonbiological nanoscale rods using photonic crystal nanotweezers. In our experiments, single microtubules (diameter 25 nm, length 8 μm) and multiwalled carbon nanotubes (outer diameter 110-170 nm, length 5 μm) are rotated by the optical torque resulting from their interaction with the evanescent field emanating from these devices. An angular trap stiffness of κ = 92.8 pN·nm/rad2·mW is demonstrated for the microtubules, and a torsional spring constant of 22.8 pN·nm/rad 2·mW is measured for the nanotubes. We expect that this new capability will facilitate the development of high precision nanoassembly schemes and biophysical studies of bending strains of biomolecules. © 2012 American Chemical Society. Source


Benbrik R.,Cadi Ayyad University | Chen C.-H.,National Cheng Kung University | Nomura T.,Korea Institute for Advanced Study
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2016

ATLAS and CMS recently showed the first results from run 2 of the Large Hadron Collider (LHC) at s=13 TeV. A resonant bump at a mass of around 750 GeV in the diphoton invariant mass spectrum was indicated and the corresponding diphoton production cross section is around 3-10 fb. Motivated by the LHC diphoton excess, we propose that the possible resonance candidate is a Higgs singlet. To produce the Higgs singlet via the gluon-gluon fusion process, we embed the Higgs singlet in the framework of the vector-like triplet quark (VLTQ) model. As a result, the Higgs singlet decaying to the diphoton final state is via VLTQ loops. Using the enhanced number of new quarks and new Yukawa couplings of the VLTQs and Higgs singlet, we successfully explain the diphoton production cross section. We find that the width of the Higgs singlet is below 1 GeV, its production cross section can be of the order of 1 pb at s=13 TeV, and the branching ratio for it decaying to a diphoton is around 0.017 and is insensitive to the masses of VLTQs and new Yukawa couplings. We find a strong correlation between the Higgs Yukawa couplings to s-b and c-t; the resulted branching ratio for t→ch can be 1.1×10-4 when the constraint from Bs oscillation is applied. With the constrained parameter values, the signal strength for the standard model Higgs decaying to a diphoton is μγγ<1.18, which is consistent with the current measurements at ATLAS and CMS. © 2016 American Physical Society. Source


Chen W.-H.,National Cheng Kung University
Journal of CO2 Utilization | Year: 2014

The catalytic partial oxidation of methane (CPOM) involves the interaction among methane combustion (MC), steam reforming (SR), and dry reforming (DR), and CO2 generated from MC is utilized for syngas production in DR. To evaluate the potential of CO2 utilization in CPOM for syngas production, a numerical study is carried out where CO2 is added into the feed gas and CPOM is triggered in a rhodium-based catalyst bed. Two important parameters of CO2/O2 ratio and O 2/CH4 ratio (or O/C ratio) in the feed gas are taken into account. The predictions suggest that CO2 addition plays no part in MC, but it retards SR and intensifies DR. The CO2 consumption increases with CO2/O2 ratio; however, the CO2 conversion goes down. As a whole, increasing CO2 addition enhances CO formation but reduces H2 formation. The maximum syngas production is exhibited at CO2/O2 = 0.2 when the O/C ratio is 1. At a fixed CO2/O2 ratio, the maximum H2 yield and CO2 consumption are located at O/C = 1.8 and 1.0, respectively. However, the CO2 conversion monotonically decreases with increasing O/C ratio. Within the investigated range of CO2/O2 and O/C ratios, the H2 yield and CO2 conversion in CPOM are in the ranges of approximately 0.42-1.34 mol(mol CH4)-1 and 10-41%, respectively. © 2013 Elsevier Ltd. All rights reserved. Source


Hsu H.-C.,National Cheng Kung University
Journal of Mathematical Fluid Mechanics | Year: 2014

We present an exact solution of the nonlinear governing equations for internal geophysical water waves propagating westward in the f-plane approximation near the equator. We show that the mass transport velocity induced by this internal equatorial wave is eastward. © 2014 Springer Basel. Source


Chen Y.-F.,Cornell University | Chen Y.-F.,National Cheng Kung University | Serey X.,Cornell University | Sarkar R.,Cornell University | And 2 more authors.
Nano Letters | Year: 2012

The ability to controllably handle the smallest materials is a fundamental enabling technology for nanoscience. Conventional optical tweezers have proven useful for manipulating microscale objects but cannot exert enough force to manipulate dielectric materials smaller than about 100 nm. Recently, several near-field optical trapping techniques have been developed that can provide higher trapping stiffness, but they tend to be limited in their ability to reversibly trap and release smaller materials due to a combination of the extremely high electromagnetic fields and the resulting local temperature rise. Here, we have developed a new form of photonic crystal "nanotweezer" that can trap and release on-command Wilson disease proteins, quantum dots, and 22 nm polymer particles with a temperature rise less than ∼0.3 K, which is below the point where unwanted fluid mechanical effects will prevent trapping or damage biological targets. © 2012 American Chemical Society. Source


Rosen J.E.,University of Waterloo | Chan L.,University of Waterloo | Shieh D.-B.,National Cheng Kung University | Gu F.X.,University of Waterloo
Nanomedicine: Nanotechnology, Biology, and Medicine | Year: 2012

Superparamagnetic iron oxide nanoparticles (SPIONs) have proven to be highly effective contrast agents for the magnetic resonance imaging diagnosis of solid tumors. This review examines the various techniques that are available to selectively target SPIONs toward a wide variety of cancerous tissues, with specific attention given to how the surface properties imparted by various targeting ligands affect the particles tissue distribution and pharmacokinetics. An in-depth examination of the various human cell lines utilized to test the assorted targeting methods is also presented, as well as an overview of the various types of cancer against which each targeting method has been utilized for both in vivo and in vitro studies. From the Clinical Editor: Functionalized superparamagnetic iron oxide nanoparticles (SPIONs) are very potent negative contrast materials for magnetic resonance imaging-based diagnosis. This comprehensive review examines techniques that selectively target SPIONs toward a wide variety of malignancies. © 2012 Elsevier Inc. Source


Young W.-B.,National Cheng Kung University
Applied Composite Materials | Year: 2013

Vacuum assisted resin transfer molding (VARTM) is one of the important processes to fabricate high performance composites. In this process, resin is drawn into the mold to impregnate the fiber reinforcement to a form composite. A resin distribution layer with high permeability was often introduced on top of the fiber reinforcement to accelerate the filling speed. Due to the difference of the flow resistance in the resin distribution layer and the reinforcement as well as the resulting through thickness transverse flow, the filling flow field is intrinsically three-dimensional. This study developed a two-layer model with two-dimensional formulation to simulate the filling flow of the VARTM process with a resin distribution layer. Two-dimensional flow was considered in each layer and a transverse flow in the thickness direction was estimated between the two layers. Thermal analysis including the transverse convection was also performed to better simulate the temperature distribution. © 2013 Springer Science+Business Media Dordrecht. Source


Hwang G.-J.,National Taiwan University of Science and Technology | Wu P.-H.,National Cheng Kung University | Chen C.-C.,National University of Tainan
Computers and Education | Year: 2012

In this paper, an online game was developed in the form of a competitive board game for conducting web-based problem-solving activities. The participants of the game determined their move by throwing a dice. Each location of the game board corresponds to a gaming task, which could be a web-based information-searching question or a mini-game; the former was used to guide the participants to search for information to answer a series of questions related to the target learning issue, while the latter was used to provide supplementary materials during the gaming process. To evaluate the performance of the proposed approach, an experiment was conducted on an elementary school natural science course. The experimental results showed that the proposed approach not only significantly promoted the flow experience, learning attitudes, learning interest and technology acceptance degree of the students, but also improved their learning achievements in the web-based problem-solving activity. © 2012 Elsevier Ltd. All rights reserved. Source


This study investigates the effectiveness digital game-based learning (DGBL) on students' problem solving, learning motivation.; academic achievement. In order to provide substantive empirical evidence, a quasi-experimental design was implemented over the course of a full semester (23 weeks). Two ninth-grade Civics and Society classes, with a total of 44 students (15-16 years old), were randomly assigned to one of two conditions: an experimental group (incorporating DGBL) and a comparison group (taught using traditional instruction). Two-way mixed ANOVA was employed to evaluate changes in problem solving ability and compare the effectiveness the two strategies, while ANCOVA was used to analyze the effects on learning motivation and academic achievement. The results of this study are summarized as follows: (1) The DGBL strategy was clearly effective in promoting students' problem solving skills, while the control group showed no improvement. Additionally, data from the mid-test and post-test demonstrate that, as a higher order thinking skill, problem-solving requires a full semester to develop. (2). DGBL resulted in better learning motivation for students in the experimental group as compared to learners receiving TI. (3) Contrary to some suggestions that digital games could inhibit academic achievement, no statistically significant difference was found between the two groups. Most importantly, the quantitative improvement in problem-solving and learning motivation suggest that DGBL can be exploited as a useful and productive tool to support students in effective learning while enhancing the classroom atmosphere. Future research in DGBL should emphasize the evaluation of other higher order elements of the cognitive domain in terms of academic achievement outcomes and skills, such as critical and creative thinking. © 2012 Elsevier Ltd. All rights reserved. Source


Wong T.-T.,National Cheng Kung University
Pattern Recognition | Year: 2012

Since naïve Bayesian classifiers are suitable for processing discrete attributes, many methods have been proposed for discretizing continuous ones. However, none of the previous studies apply more than one discretization method to the continuous attributes in a data set for naïve Bayesian classifiers. Different approaches employ different information embedded in continuous attributes to determine the boundaries for discretization. It is likely that discretizing the continuous attributes in a data set using different methods can utilize the information embedded in the attributes more thoroughly and thus improve the performance of naïve Bayesian classifiers. In this study, we propose a nonparametric measure to evaluate the dependence level between a continuous attribute and the class. The nonparametric measure is then used to develop a hybrid method for discretizing continuous attributes so that the accuracy of the naïve Bayesian classifier can be enhanced. This hybrid method is tested on 20 data sets, and the results demonstrate that discretizing the continuous attributes in a data set by various methods can generally have a higher prediction accuracy. © 2011 Elsevier Ltd. All rights reserved. Source


Huang J.-F.,National Cheng Kung University | Huang C.-M.,Chung Shan Institute of Science and Technology | Yang C.-C.,Kun Shan University
IEEE Transactions on Information Theory | Year: 2012

One approach for designing the one-coincidence sequence (OCS) low-density parity-check (LDPC) codes of large girth is investigated. These OCS-LDPC codes are quasi-cyclic, and their parity-check matrices are composed of circulant permutation matrices. Generally, the cycle structures in these codes are determined by the shift values of circulant permutation matrices, and the existence of cycles in the corresponding Tanner graph is governed by certain cycle-governing equations (CGEs). Therefore, finding the proper shift values is the key point to increase the girth of these codes. In this paper, we provide an effective method to systematically find out the CGEs for these codes of girth 6, 8, and 10, respectively. Then, one less computation-intensive algorithm is used to generate the proper shift values for constructing the OCS-LDPC codes of large girth. Simulation results show that significant gains in signal-to-noise ratio over an additive white-Gaussian noise channel can be achieved by increasing the girth of the OCS-LDPC codes. © 2012 IEEE. Source


Yu F.-Y.,National Cheng Kung University
Computers and Education | Year: 2011

In view of the current theoretical and empirical support for a student-generated questions approach to learning along with the advantageous features of network technology, several online student question-generation learning systems with a peer-assessment component have been developed. Despite this, all existing systems are limited in terms of the types of communication modes permissible for peer-assessment. Online discourse experience and the quantity and quality of interaction may vary as a result of the specific interaction mode students are exposed to. Because of this and the fact that versatile learning spaces are both possible and potentially desirable during the various stages of learning and teaching, multiple peer-assessment modes were created, and the overall attitudes of learners toward peer-assessment as well as their preferences toward respective peer-assessment modes were examined. The collected data confirmed the perceived usefulness of peer-assessment for developing higher-order thinking and cognitive elaboration. Support was demonstrated for student question-generation activities, for which learners typically have limited prior experience. Additionally, in light of the apparent overwhelming preference for and superiority of the more interactive two-way and multi-way modes over the one-way mode and the perceived learning potential of these modes, it is suggested that designers of similar systems should consider their inclusion. Finally, even though multi-way learning was found to be both the preferred and most supportive mode for learning, students also revealed distinct reasons for their preferences for respective interaction modes. In general, these reasons supported the premise that multiple peer-assessment modes are needed in order to accommodate individual preferences and needs. Suggestions and implications for instructional implementation, system development, and future studies are offered. © 2010 Elsevier Ltd. All rights reserved. Source


Lin P.D.,National Cheng Kung University
Journal of the Optical Society of America A: Optics and Image Science, and Vision | Year: 2011

The second-order derivative matrix of a scalar function with respect to a variable vector is called a Hessian matrix, which is a square matrix. Our research group previously presented a method for determination of the first-order derivatives (i.e., the Jacobian matrix) of a skew ray with respect to the variable vector of an optical system. This paper extends our previous methodology to determine the second-order derivatives (i.e., the Hessian matrix) of a skew ray with respect to the variable vector of its source ray when this ray is reflected/refracted by spherical boundary surfaces. The traditional finite-difference methods using ray-tracing data to compute the Hessian matrix suffer from various cumulative rounding and truncation errors. The proposed method uses differential geometry, giving it an inherently greater accuracy. The proposed Hessian matrix methodology has potential use in optimization methods where the merit function is defined as ray aberrations. It also can be used to investigate the shape of the wavefront for a ray traveling through an optical system. © 2011 Optical Society of America. Source


HRJ (Hydro-processed Renewable Jet) conversion technology has been recently used to produce renewable jet fuel for commercial or military flights. In this study, a techno-economic analysis is carried out for evaluating the production of jatropha-derived HRJ fuel through a bio-refinery process. Each component of the chosen feedstock jatropha can be converted into valuable products. The bio-refinery process is split into 6 parts: (1) Fruit Dehulling; (2) Shell Combustion; (3) Oil Extraction; (4) Press Cake Pyrolysis; (5) Oil Upgrading; (6) Product Separation. The minimum jet fuel selling price (MJSP) from this fruit scenario is calculated to be $5.42/gal based on the plant capacity of 2400 metric tonne of feedstock per day. The co-products obtained from the process not only significantly deduct the production cost but make the entire process energy self-sustainable. We also discuss the oil scenario, which oil is the starting material and the process begins from Oil Upgrading section. The oil scenario offers the MJSP of $5.74/gal with lower capital but higher operating costs. The differences of MJSPs for fruit and oil scenarios are due to feedstock cost, refinery capital cost, co-product credits and energy cost. Based on the sensitivity analysis, the feedstock price, oil content, plant capacity, reactor construction and catalyst usage are important parameters that control the price of the produced fuel. © 2016 Elsevier Ltd. Source


Wen C.-D.,National Cheng Kung University
International Journal of Heat and Mass Transfer | Year: 2010

Steel emissivity behaviors were investigated in this study. Experiments were conducted to measure emissivity. Six emissivity models were then applied to examine Multispectral Radiation Thermometry (MRT) on inferring surface temperature. The data show that emissivity decreases with increasing wavelength. For steel containing high chromium, emissivity is usually lower than others because of the chromium oxide protection layer. Two emissivity models provide the best overall compensation for different alloys, number of wavelengths, and temperatures. The results reveal that if the emissivity model can well represent the real emissivity behaviors, the more accurate inferred temperature can be achieved. © 2009 Elsevier Ltd. All rights reserved. Source


Hwang I.-S.,National Cheng Kung University
European Journal of Applied Physiology | Year: 2011

This study was undertaken to investigate the effect of low-level loading on digit tracking and the associated physiological tremors in the moving and the stationary digits. Sixteen healthy adults conducted positional tracking with the middle finger under the loaded and unloaded conditions; meanwhile, trajectory of the middle finger, electromyographic activities of the extensor digitorum (ED)/flexor digitorum superficialis, and physiological tremors of the index, middle, ring, and little fingers were recorded. The results showed that load imposition (<70 g) on the middle finger improved tracking congruency, in association with reduction of inter-digit tremor coupling and enhancement of tiny movement jerks. Principal component analysis suggested that inertial load suppressed the 8-12 Hz central rhythm but potentiated the 25-40 Hz coherence spectra of major principal components and electromyographic signals of the ED. It was concluded that low-level inertial load could facilitate corrective movement adjustments and selective digit control during manual tracking, relevant implicitly to decreased common central drive and enhanced heteronymous reflex loops. © 2010 Springer-Verlag. Source


Kao C.,National Cheng Kung University
International Journal of Production Economics | Year: 2010

Congestion is a wasteful stage of the production process where outputs are reduced due to excessive amount of inputs. This paper investigates three types of models prevailing in the data envelopment analysis literature, i.e., the Färe-family model, the Cooper-family model, and the Wei-Tone model, for measuring the congestion effect. The Färe-family model is able to decompose technical efficiency into the product of pure technical efficiency and congestion effect, yet fails to detect congestion in some situations. The Cooper-family model successfully detects congestion in all situations, yet is unable to differentiate pure technical efficiency with the congestion effect. The Wei-Tone model does not have the aforementioned deficiencies, yet is unable to identify the excessive amounts of each input. To illustrate how to eliminate congestion in reality, the Wei-Tone model is utilized to measure the congestion effect of Taiwan forests. There are three forest districts found to have different extents of congestion. The theoretical method of deleting excessive inputs to improve efficiency is actually impractical in this case. By means of reorganization, this paper finds that the congestion effects of two districts are eliminated and the other is alleviated. © 2009 Elsevier B.V. All rights reserved. Source


Chen H.-H.,National Cheng Kung University
IEEE Wireless Communications | Year: 2014

Dear readers, Time flies! The holiday season comes again. It is time for us to prepare for the annual celebration of Christmas and the New Year. Therefore, I would like to take this wonderful opportunity to send my warmest greetings to all of you. In particular, I would like to send my best wishes to all Editorial Board members, who have worked extremely hard to handle the reviews of submissions for this magazine. My greetings should also go to the publications staff of IEEE Communications Society for their great help to the magazine in publishing papers in a timely manner. © 2002-2012 IEEE. Source


Lin C.-C.,National Cheng Kung University
International Journal of Production Economics | Year: 2010

The network industries design and operate physical distribution networks to provide services for spatial interactions. In the hierarchical hub-and-spoke network, each center is connected through a secondary route to its designated hub, while hubs are mutually connected by primary routes. It is a variation of pure hub-and-spoke networks that may eliminate center-hub partial loads with the result of higher load factor and lower cost. We study the integrated hierarchical hub-and-spoke network design problem for dual services. It integrates otherwise mutually exclusive secondary route networks for their respective services so that the total operating cost is minimized while meeting the service time and operations restrictions. Assuming symmetry in cost/time, it is equivalent to the integration of dual degree and time constrained trees. We propose a directed network configuration and formulate a link-based integer mathematical model. We also develop a link-based implicit enumeration with an embedded degree and time constrained spanning tree algorithm. The computational result showed that the integration provides a substantial cost reduction over the conventional exclusive secondary route networks for their respective services. In addition, the proper selection of number and location of hubs may achieve a higher cost-effectiveness as well as an increase in service territory at no additional operating cost. © 2009 Elsevier B.V. All rights reserved. Source


Lin Y.-J.,Fooyin University | Lin H.-T.,National Cheng Kung University
Building and Environment | Year: 2011

The need for the better use of scarce planetary resources has never been more evident than it is today. However, this need is poorly reflected in human housing. In recent years, there has been a growing realization of the importance of constructing human shelters that better conserve energy and water through appropriate insulation and architectural designs. Among the important advancements in these areas is the use of rooftop greeneries for both energy and water conservation. This paper performs an investigation into this topic within the specific climatic context of tropical regions. Long-term experimental results are provided from a four-floor building in Kaohsiung in the southern part of Taiwan. The study involves a fully monitored extensive rooftop greenery and examines four different plant substrates, three different irrigation regimes, and different types of drought-enduring plants to find the most efficient combination of all three in providing maximum heat insulation and water usage efficiency. The attenuation of solar radiation through the vegetation layer is evaluated, as well as the thermal insulation performance of the rooftop greenery structure. Among the substrates, burned sludge has the best thermal reduction percentage of heat amplitude under the roof slab surface (up to 84.4%). Irrigation twice a week has the best thermal reduction percentage of heat amplitude (91.6%). Among the plant types, Sansevieria trifasciata cv. Laurentii Compacta and Rhoeo spathaceo cv. Compacta are found to be suitable for extensive rooftop greeneries because they have the best coverage ratio and are most drought enduring. © 2010 Elsevier Ltd. Source


Chiang K.W.,National Cheng Kung University
Sensors (Basel, Switzerland) | Year: 2013

The integration of an Inertial Navigation System (INS) and the Global Positioning System (GPS) is common in mobile mapping and navigation applications to seamlessly determine the position, velocity, and orientation of the mobile platform. In most INS/GPS integrated architectures, the GPS is considered to be an accurate reference with which to correct for the systematic errors of the inertial sensors, which are composed of biases, scale factors and drift. However, the GPS receiver may produce abnormal pseudo-range errors mainly caused by ionospheric delay, tropospheric delay and the multipath effect. These errors degrade the overall position accuracy of an integrated system that uses conventional INS/GPS integration strategies such as loosely coupled (LC) and tightly coupled (TC) schemes. Conventional tightly coupled INS/GPS integration schemes apply the Klobuchar model and the Hopfield model to reduce pseudo-range delays caused by ionospheric delay and tropospheric delay, respectively, but do not address the multipath problem. However, the multipath effect (from reflected GPS signals) affects the position error far more significantly in a consumer-grade GPS receiver than in an expensive, geodetic-grade GPS receiver. To avoid this problem, a new integrated INS/GPS architecture is proposed. The proposed method is described and applied in a real-time integrated system with two integration strategies, namely, loosely coupled and tightly coupled schemes, respectively. To verify the effectiveness of the proposed method, field tests with various scenarios are conducted and the results are compared with a reliable reference system. Source


Huang C.-C.,National Cheng Kung University
Journal of Hydrology | Year: 2011

Although sophisticated models for predicting spatial and temporal rainstorm patterns have been proposed in past decades, the temporal patterns of extreme rainstorm events are still unknown, and the performance of natural and man-made slopes and debris flow mitigation measures have never been assessed from the viewpoint of temporal rainfall patterns. To this end, three methods were used to simulate the hyetograph of an extreme rainstorm, namely, typhoon Morakot, which resulted in a maximum rainfall of 2884mm in Taiwan from August 6-11, 2009. It was found that Gaussian-based hyetographs better simulated the rainstorm patterns recorded in the study area than conventional triangular and instantaneous intensity methods. Based on a satellite image investigation, a total of 32 events of reported debris flow disasters were identified with accurate times of debris flow strike and clear causative source slope failures adjacent to the disaster sites. Fundamental statistical parameters, namely the simulated time of peak rainfall intensity, tp, and the standard deviation of rainfall duration, σt, were used to correlate the time of debris flow initiation. It was found that 94% (30 out of 32 events) of the investigated debris flows occurred between tp-0.5σt and tp+1.0σt, suggesting that intensive slope failures and debris flows occurred around the peak of hourly rainfall, associated with the steepest segment of the mass curve. It was also found that sites with larger source slope failure areas tended to have a longer delay between the time of peak hourly rainfall and the occurrence of debris flow. Results of the analyses revealed the potential of improving the accuracy of debris flow predictions using the proposed hyetograph method. © 2011 Elsevier B.V. Source


Liu Y.-C.,National Cheng Kung University
Robotica | Year: 2014

This paper proposes control algorithms for heterogeneous teleoperation systems to guarantee stability and tracking performance in the presence of time-varying communication delays. Because robotic manipulators, in most applications of bilateral teleoperation systems, interact with a human operator and remote environment on the end-effector, the control system is developed in the task-space. When the dynamic parameters of the robots are unknown and the communication network is subject to time-varying delay, the developed controller can ensure stability and task-space position tracking. Additionally, if the robotic systems are influenced by human and environmental forces, the presented teleoperation control system is demonstrated to be stable and all signals are proven to be ultimately bounded. By employing the redundancy of the slave robot for sub-task control, the proposed teleoperation system can autonomously achieve additional missions in the remote environment. Numerical examples utilizing a redundant planar robot are addressed to validate the proposed task-space teleoperators with time-varying delay. Copyright © Cambridge University Press 2014. Source


Ju S.H.,National Cheng Kung University
Engineering Computations (Swansea, Wales) | Year: 2014

Purpose - This paper develops C and Fortran-90 solvers to establish parallel solution procedures in a finite element or meshless analysis program using shared memory computers. The paper aims to discuss these issues. Design/methodology/approach - The stiffnessmatrix can be symmetrical or unsymmetrical, and the solution schemes include sky-line Cholesky and parallel preconditioned conjugate gradient-like methods. Findings - By using the features of C or Fortran-90, the stiffness matrix and its auxiliary arrays can be encapsulated into a class or module as private arrays. This class or module will handle how to allocate, renumber, assemble, parallelize and solve these complicated arrays automatically. Practical implications - The source codes can be obtained online at http//myweb.ncku.edu.tw/,juju. The major advantage of the scheme is that it is simple and systematic, so an efficient parallel finite element or meshless program can be established easily. Originality/value - With the minimum requirement of computer memory, an object-oriented C class and a Fortran-90 module were established to allocate, renumber, assemble, parallel, and solve the global stiffness matrix, so that the programmer does not need to handle them directly. © 2013 Emerald Group Publishing Limited. Source


Liu Y.-C.,National Cheng Kung University | Chopra N.,University of Maryland University College
Automatica | Year: 2013

In teleoperation systems operating in complex environments, due to the cognitive limitations of the human operator and lack of complete information about the remote environment, safety and performance of such systems can potentially be comprised. In order to ensure the safety and enhance the efficiency of complex teleoperation systems operating in cluttered environments, in this paper we investigate a semi-autonomous control framework for bilateral teleoperation. The semi-autonomous teleoperation system is composed of heterogeneous master and slave robots, where the slave robot is assumed to be a redundant manipulator. Considering robots with different configurations, and in the presence of dynamic uncertainties and asymmetric communication delays, we first develop a control algorithm to ensure position and velocity tracking in the task space. Additionally in the absence of dynamic uncertainty, and in the presence of human operator and environmental forces, all signals of the proposed teleoperation system are proven to be ultimately bounded. The redundancy of the slave robot is then utilized for achieving autonomous sub-task control, such as singularity avoidance, joint limits, and collision avoidance. The control algorithms for the proposed semi-autonomous teleoperation system are validated through numerical simulations on a non-redundant master and a redundant slave robot. © 2013 Elsevier Ltd. All rights reserved. Source


Kao C.,National Cheng Kung University | Lin P.-H.,Southern Taiwan University of Science and Technology
Fuzzy Sets and Systems | Year: 2012

This paper investigates the problem of efficiency measurement for parallel production systems where a number of processes are operating independently within the system, and some input/output data are fuzzy numbers. When all observations have precise values, previous studies found that the system efficiency measured from a relational data envelopment analysis model is a weighted average of the process efficiencies. Based on the extension principle of fuzzy theory, this paper constructs a pair of two-level programming models to calculate the lower and upper bounds of the α-cuts of the fuzzy system and process efficiencies. It is shown that the fuzzy system efficiency is still a weighted average of the fuzzy process efficiencies. However, the weights need not be the same at different α levels. The case of measuring the teaching and research efficiencies of chemistry departments in UK universities with a qualitative factor of research quality discussed in the literature is used as an example to explain the idea of this paper. Fuzzy measures obtained from fuzzy observations are more informative than crisp measures obtained from assuming the fuzzy observations to be precise. © 2012 Elsevier B.V. Source


Ju S.H.,National Cheng Kung University
Engineering Structures | Year: 2013

The main purpose of this study is to investigate the improvement of bridge structures to increase the safety of moving trains during earthquakes using finite element analyses, where nonlinear moving wheel elements are used to simulate the contact and separation modes of rails and wheels. The bridges are standard multi-span bridges for a high-speed rail system. The results of parametric studies with over 320 analyses indicate that the improvement in the train safety for multi-span bridges with several continuous spans is not observable. Large gaps between two simply supported girders during earthquakes will increase the train derailment coefficient, and thus a reduction in the eccentricity between two girders can enhance the safety of moving trains. Additionally, because the first train natural frequencies are often in the low frequency range, large pier stiffness producing high bridge natural frequencies can confine the train derailment coefficients near a normal value, even in the resonance between bridges and earthquakes, so we suggest that large pier stiffness should be used to ensure the safety of moving trains during earthquakes. © 2013 Elsevier Ltd. Source


Jeng D.J.-F.,National Cheng Kung University
International Journal of Innovative Computing, Information and Control | Year: 2012

Technology projects typically carry a high rate of failure. Project management refers to disciplines that enhance management of inherent strengths and weaknesses of a project. In contrast to external factors, project management frequently ignores internal factors. Such factors, involving internal services within the team, focus on working with people, ensuring customer satisfaction, and creating a conducive environment for the project team to deliver high quality products, which meet stakeholder expectations. This research investigated the intertwined effects of project team internal factors, and proposes a hybrid method that combines exploratory factor analysis and the Decision Making Trial and Evaluation Laboratory (DEMATEL) technique to solve an empirical case. Exploratory factor analysis was applied for extracting the dimension and criteria structure of internal factors. The DEMATEL technique was then used to analyze the intertwined effect. This research found, in the dimensional level, attitude highly inflences other internal factors towards project success, while work loading is a key factor in criteria level that greatly influences all others. The proposed method has proven to be effective for analyzing the complex interrelation of human psychological concerns. © 2012 ICIC International. Source


Ju S.H.,National Cheng Kung University
Archive of Applied Mechanics | Year: 2013

This paper investigates the derailment of trains moving on multi-span simply supported bridges with foundation settlements or rotations. Rail irregularities, train-track-bridge interactions, and wheel/rail separations were considered in the three-dimensional nonlinear finite element analysis. A moving spring-mass with separation and contact modes was used to validate the proposed finite element model. In the parametric study, finite element results indicate that foundation settlements or rotations cause sharp displacements between two simply supported girders, which generate large train derailment coefficients. The train derailment coefficients rise with increased train speed, and they greatly increase at a critical speed. The time history displacements of a train obviously contain a jump when it passes a location with foundation settlements or rotations, so a warning system can be established using this measurement. © 2012 Springer-Verlag. Source


Sou S.-I.,National Cheng Kung University
IEEE Transactions on Communications | Year: 2013

In a Vehicular Ad Hoc Network (VANET), the wireless Collision Avoidance (CA) system issues warnings to drivers before they reach a potentially dangerous zone on the road. This paper proposes an analytical model for evaluating the performance of emergency messaging via wireless CA systems. First, we utilize the dichotomized headway model, the braking model, and Greenberg's logarithmic model to generate vehicular mobility traces for analysis. Second, we derive the probability of a rear-end collision between two vehicles that travel in the same direction when a sudden event occurs. Third, we quantify the probability of vehicles failing to receive the emergency message. Numerical results from the model show that the number of car crashes per accident is much higher when a wireless CA system is not used. We also find it interesting that the number of car crashes is not directly proportional to the vehicle density when the vehicular mobility traces follow the speed-density relationship offered by Greenberg's logarithmic model. By integrating flow theory into VANET analysis, our model provides useful insights for future intelligent transportation. © 1972-2012 IEEE. Source


Huang C.-C.,National Cheng Kung University
Geotextiles and Geomembranes | Year: 2014

Formulation and verification for a force equilibrium-based finite displacement method (FFDM) using test results of reinforced model slopes subjected to increasing pseudo-static seismic forces are reported. The FFDM requires, in addition to force equilibrium for a sliced potential failure mass, a hyperbolic shear stress-displacement constitutive law for the backfill soils, a hyperbolic pull-out force-displacement constitutive law for the reinforcement, and a displacement compatibility requirement for adjacent soil slices. As a result, the mobilized reinforcement force is an analytical output, rather than an empiricism-based input as required in conventional limit equilibrium analyses. Analytical results from the FFDM also indicated that a brittle failure is associated with the lightly reinforced failure surface; a ductile failure is associated with the heavily reinforced failure surface, regardless of the extensibility of reinforcement investigated in the present study. Good agreements between the measured and the computed slope displacements and reinforcement forces in response to increases in pseudo-static seismic forces suggest that the FFDM can be used as an analytical tool for evaluating displacements of reinforced slopes subjected to pseudo-static seismic loads. © 2014. Source


Huang Y.-H.,Chung Yuan Christian University | Wu J.-H.,National Cheng Kung University
Energy | Year: 2013

Between 1996 and 2006, CO2 emissions in Taiwan increased by approximately 60%, with the industrial sector accounting for 50% of that increase. Among all industrial sectors, iron and steel, petrochemicals, electronics, textiles, pulp and paper and cement accounted for approximately three-quarters of the total industrial CO2 emissions. Identifying the driving forces behind increased CO2 emissions in these six sectors could be valuable for the development of effective environmental policy. This study used two-tier KLEM input-output structural decomposition analysis (I-O SDA) to analyze the factors that lead to changes in CO2 emissions. Empirical results obtained in Taiwan reveal that increased exports level and elevated domestic autonomous final demand level were the main reasons for increases in CO2 emissions. Technological changes in materials and labor tended to decrease CO2 emissions, while the power generation mix contributed significantly to the increase. Relevant strategies for reducing CO2 emissions from energy-intensive sectors are also highlighted. © 2013 Elsevier Ltd. Source


Chen W.-T.,National Cheng Kung University
IEEE Transactions on Automation Science and Engineering | Year: 2014

Dynamic frame slotted Aloha (DFSA) has been widely adopted to solve the anticollision problem in a radio frequency identification (RFID) system. In a DFSA procedure, the interrogator needs to continuously estimate tag backlog and select a new frame length for identifying the backlog. Intuitively, the accuracy of the tag estimator will affect the read performance. Hence, a considerable amount of research effort has been invested to improve the accuracy of backlog estimation. The improvement in general comes at the expense of large computation load and may lead to a serious challenge if one needs to implement such a kind of estimators in a real RFID system. This paper analyzes the influence of estimation error on read performance. Based on the analysis, we propose a feasible and easy-to-implement anticollision algorithm. Our proposed algorithm can achieve a normalized throughput of 35% that is very close to the theoretical maximum 36.1% for an EPCglobal UHF Class-1 Generation-2 system. The easy-to-implement advantage of our algorithm comes at the expense of only 1% reduction in normalized throughput as compared with the case where maximum throughput can be obtained. The results obtained are useful in designing fast and efficient interrogators. © 2004-2012 IEEE. Source


Enterovirus 71 (EV71) has emerged as a neuroinvasive virus responsible for several large outbreaks in the Asia-Pacific region while virulence determinant remains unexplored. In this report, we investigated increased virulence of unadapted EV71 clinical isolate 237 as compared with isolate 4643 in mice. A fragment 12 nucleotides in length in stem loop (SL) II of 237 5'-untranslated region (UTR) visibly reduced survival time and rate in mice was identified by constructing a series of infectious clones harboring chimeric 5'-UTR. In cells transfected with bicistronic plasmids, and replicon RNAs, the 12-nt fragment of isolate 237 enhanced translational activities and accelerated replication of subgenomic EV71. Finally, single nucleotide change from cytosine to uridine at base 158 in this short fragment of 5'-UTR was proven to reduce viral translation and EV71 virulence in mice. Results collectively indicated a pivotal role of novel virulence determinant C158 on virus translation in vitro and EV71 virulence in vivo. These results presented the first reported virulence determinant in EV71 5'-UTR and first position discovered from unadapted isolates. Source


Lee Y.S.,National Cheng Kung University
Mediators of inflammation | Year: 2013

Several studies have provided evidence with regard to the neuroprotection benefits of hyperbaric oxygen (HBO) therapy in cases of stroke, and HBO also promotes bone marrow stem cells (BMSCs) proliferation and mobilization. This study investigates the influence of HBO therapy on the migration of BMSCs, neurogenesis, gliosis, and inflammation after stroke. Rats that sustained transient middle cerebral artery occlusion (MCAO) were treated with HBO three weeks or two days. The results were examined using a behavior test (modified neurological severity score, mNSS) and immunostaining to evaluate the effects of HBO therapy on migration of BMSCs, neurogenesis, and gliosis, and expression of neurotrophic factors was also evaluated. There was a lower mNSS score in the three-week HBO group when compared with the two-day HBO group. Mobilization of BMSCs to an ischemic area was more improved in long course HBO treatments, suggesting the duration of therapy is crucial for promoting the homing of BMSCs to ischemic brain by HBO therapies. HBO also can stimulate expression of trophic factors and improve neurogenesis and gliosis. These effects may help in neuronal repair after ischemic stroke, and increasing the course of HBO therapy might enhance therapeutic effects on ischemic stroke. Source


Hsu W.-Y.,Academia Sinica, Taiwan | Hsu W.-Y.,National Cheng Kung University
Microscopy Research and Technique | Year: 2011

Image registration is an important topic in medical image analysis. It is usually used to reconstruct 3D structure of tissues from a series of microscopic images. However, a variety of inherent factors may result in great differences between acquired slices during imaging even if they are adjacent. The common differences include the color difference and geometry discrepancy, which make the registration problem a difficult challenge. In this study, we propose a robust registration method to automatically reconstruct 3D volume data of the rat brain. It mainly consists of three procedures, including multiscale wavelet-based feature extraction, analytic robust point matching (ARPM), and registration refinement with feature-based modified Levenberg-Marquardt algorithm (FMLM). The product of gradient moduli in multi-scales is used to decide if extracted feature points are true according to the characteristic that features could exist in multiscale. The ARPM registration algorithm is proposed to speedily accomplish the registration of two point sets with different size by simultaneously evaluating the spatial correspondence and geometrical transformation. In addition, a FMLM method is also proposed to further refine registration results and achieve subpixel accuracy. The FMLM method converges much faster than most other methods due to its feature-based and nonlinear characteristic. The performance of proposed method is evaluated by comparing it with well-known thin-plate spline robust point matching (TPS-RPM) algorithm. The results indicate that ARPM-FMLM algorithm is a robust and fast method in image registration. © 2010 Wiley-Liss, Inc. Source


Suen J.-P.,National Cheng Kung University
Water Resources Management | Year: 2011

Maintaining the natural variability of a river's flow regime is one of the most critical strategies sustaining the ecological integrity of aquatic ecosystems. This research seeks to determine the ecological flow regime for management of streamflow existing reservoirs. The ecological flow regime is a human-modified flow regime that captures the natural flow variability for maintaining the structure and the functional integrity of the aquatic ecosystems. The design procedure uses regionalization analysis, the ratio method, and linear regression analysis techniques with hydrologic indicators to simulate the altered flow variability caused by human-based annual streamflow reduction. Because it is difficult for reservoir operators to achieve the strict standard of natural flow regime, a discontinuity ratio method is used to express the reservoir's expected effect on the change in hydrologic indicator values. The final product of the ecological flow regime analysis produces a target reservoir operation and management that will provide a flow regime necessary to sustain the integrity of aquatic ecosystems. © 2010 Springer Science+Business Media B.V. Source


Wu W.-S.,National Cheng Kung University
Bioinformatics and Biology Insights | Year: 2011

Transcription factors control gene expression by binding to short specific DNA sequences, called transcription factor binding sites (TFBSs), in the promoter of a gene. Thus, studying the spatial distribution of TFBSs in the promoters may provide insights into the molecular mechanisms of gene regulation. I developed a method to construct the spatial distribution of TFBSs for any set of genes of interest. I found that different functional gene clusters have different spatial distributions of TFBSs, indicating that gene regulation mechanisms may be very different among different functional gene clusters. I also found that the binding sites for different transcription factors (TFs) may have different spatial distributions: A sharp peak, a plateau or no dominant single peak. The spatial distributions of binding sites for many TFs derived from my analyses are valuable prior information for TFBS prediction algorithm because different regions of a promoter can assign different possibilities for TFBS occurrence. © the author(s). Source


Huang W.-H.,National Cheng Kung University
Nuclear Physics B | Year: 2012

The Lagrangians of self-dual gauge theory in various formulations are reviewed. From these results we see a simple rule and use it to present some new non-covariant Lagrangian based on the decomposition of spacetime into D=D 1+D 2+D 3. Our prescription could be easily extended to more complex decomposition of spacetime and some more examples are presented therefore. The self-dual property of the new Lagrangian is proved in detail. We also show that the new non-covariant actions give field equations with 6d Lorentz invariance. © 2012 Elsevier B.V. Source


Observed increases in the Earth's surface temperature bring with them associated changes in precipitation and atmospheric moisture that consequentially alter river flow regimes. Climate-induced flow regime changes are examined using the Indicators of Hydrologic Alteration. This article uses observed daily streamflow data to examine the flow regime alteration and how these changes might potentially affect freshwater ecosystems. Flow data from 23 gauging stations throughout Taiwan show that the annual extreme water conditions (1-, 3-, 7-, 30-, 90-day annual minima or maxima) have increased alteration compared to baseline periods (1961-1990). Specifically, more severe flood and drought events occur in the period after 1991 than the period from 1961 to 1990. The frequency and duration of flood and drought events also show increased fluctuation. Flow regimes are currently being altered by stressors that will continue into the foreseeable future and it is also happing elsewhere in the world. Aquatic organisms not only need to defend themselves from anthropogenic damage to the river system, but also face the on-going threat from climate change-induced thermal and flow regime alteration. This article raises this issue so that water resources managers may identify precautionary measures that reduce the cumulative effects of both anthropogenic flow alteration and changing climate conditions. © 2010 Springer Science+Business Media B.V. Source


Yu C.-H.,National Cheng Kung University | Pang Y.-H.,National University of Kaohsiung
IEEE Microwave and Wireless Components Letters | Year: 2013

A planar dual-band quadrature branch-line coupler with coupled lines is presented in this letter. The quarter-wavelength transformers in a conventional branch-line coupler are replaced by coupled lines. With derived explicit design formula, the proposed branch-line coupler can not only be operated at two arbitrary frequencies, but it can also exhibit the required output power ratio at the designed dual frequencies. The measured return losses and isolation are all better than 16 dB at the operating frequencies. Phase imbalance less than 1̂ is obtained. The measured data validate the proposed design methodology, and show good agreement with the simulation results. © 2001-2012 IEEE. Source


Cheng K.-W.,National Cheng Kung University | Je M.,Institute of Microelectronics, Singapore
IEEE Microwave and Wireless Components Letters | Year: 2013

This letter presents the design and analysis for a low-phase-noise and low-power Colpitts quadrature voltage-controlled oscillator (QVCO). The Colpitts QVCO employs current switching to lower the phase noise, gm enhancement to improve the startup condition in the oscillator core, and device reuse to realize anti-phase injection locking for QVCO operation. The proposed Colpitts QVCO has superior phase noise than cross-coupled LC tank VCO and outperforms conventional QVCO in phase noise, quadrature phase accuracy, and tuning range. The fabricated 0.18 μm CMOS Colpitts QVCO draws 500 μA from a 1.5 V power supply and exhibits a phase noise of -118 dBc/Hz at 1 MHz offset and a quadrature phase error of 0.3° at the center frequency of 488 MHz. © 2001-2012 IEEE. Source


Wang N.-C.,National United University | Lee C.-Y.,National Cheng Kung University
Information Sciences | Year: 2012

Mobile multimedia applications have recently generated much interest in mobile ad hoc networks (MANETs) supporting quality-of-service (QoS) communications. Due to the limited bandwidth of a wireless node, a QoS multicast routing is often blocked if there is not a single multicast tree with the requested bandwidth, even when there is sufficient bandwidth in the network to support the call. In this paper, a multi-path QoS multicast routing (MQMR) protocol for MANETs is proposed. The scheme offers dynamic time slot control using a multi-path tree (or a uni-path tree) to meet the bandwidth requirements of a call. The final multi-path QoS multicast tree meets the QoS requirements, and the aggregate bandwidth of the paths meets the bandwidth requirements of a call. To avoid the hidden terminal problem or insufficient bandwidth in the bandwidth reservation process, each destination uses a decision rule. Moreover, a bandwidth reservation scheme is used for selecting the reserved time slots on each node in the multi-path QoS multicast tree. Simulation results demonstrate the effectiveness of MQMR in reducing network blocking and improving the call success ratio. © 2012 Elsevier Inc. All rights reserved. Source


Saon G.,IBM | Chien J.-T.,National Cheng Kung University
IEEE Signal Processing Magazine | Year: 2012

Over the past decade or so, several advances have been made to the design of modern large vocabulary continuous speech recognition (LVCSR) systems to the point where their application has broadened from early speaker dependent dictation systems to speaker-independent automatic broadcast news transcription and indexing, lectures and meetings transcription, conversational telephone speech transcription, open-domain voice search, medical and legal speech recognition, and call center applications, to name a few. The commercial success of these systems is an impressive testimony to how far research in LVCSR has come, and the aim of this article is to describe some of the technological underpinnings of modern systems. It must be said, however, that, despite the commercial success and widespread adoption, the problem of large-vocabulary speech recognition is far from being solved: background noise, channel distortions, foreign accents, casual and disfluent speech, or unexpected topic change can cause automated systems to make egregious recognition errors. This is because current LVCSR systems are not robust to mismatched training and test conditions and cannot handle context as well as human listeners despite being trained on thousands of hours of speech and billions of words of text. © 2012 IEEE. Source


Chen C.-L.,National Cheng Kung University | Chen C.-L.,National Kaohsiung Marine University
Marine Policy | Year: 2011

Taiwan has shifted from harvesting whales and dolphins to protecting all cetacean species since 1990. Whales and dolphins have become major tourist attractions. With an eye on foreseeable future growth and increasing concerns about environmental impact, service delivery, and educational efficacy, the government seeks to achieve the overall quality assurance of whale/dolphin watching tourism by introducing an ecolabelling program. The aim of this study is to examine this program by analyzing its impact on tour operators and visitors. A survey method was used to assess the impact. The results showed that the program is having a positive impact on operators by seeking environmental sustainability and has brought about educational benefits for visitors, including: site-based knowledge, awareness of marine conservation and reinforcing intentions to perform environmentally responsible behaviors. However, money cost is a major factor discouraging tour operator's participation, even though ecolabels help to construct an image of responsibility. With potential educational benefits for visitors in mind, the study highlights the need for increasing public awareness of the program, expanding marketing of ecolabelled products, and providing economic incentives for tour operators to engage in ecolabelling. © 2010 Elsevier Ltd. Source


Shiau J.-T.,National Cheng Kung University
Water Resources Research | Year: 2011

This study analytically derives optimal hedging for a water supply reservoir considering balance between beneficial release and carryover storage value. With the reservoir operation goal expressed as a weighted sum of loss functions (i.e., normalized deviations from targets) for current release and carryover storage, the derived optimal hedging is a linear function of water availability. This analytical optimal hedging is generalized to represent two-point as well as one-point hedging. The relationship between the weighting factor and the ratio of release target to total target can be used to detect two types of two-point hedging. A factor called the inverse-weighted target ratio (composed of a weighting factor and release and carryover storage targets) is developed to simplify derived optimal hedging and distinguish these two types of hedging, which are classified as the factors less than or equal to 1 and greater than or equal to 1, respectively. One-point hedging is a special case where these two types of two-point hedging coincide and this factor equals 1. By explicitly incorporating release and carryover storage targets as well as a weighting factor and an exponent of loss functions, effects of these components on reservoir hedging can be evaluated analytically. Since reservoir release is also a linear function of reservoir inflow, analytical assessment of hedging uncertainty induced by inflow is made possible. The proposed methodology is applied to the Shihmen Reservoir in northern Taiwan to illustrate effects of derived optimal hedging on reservoir performance in terms of shortage-related indices and hedging uncertainty. © 2011 by the American Geophysical Union. Source


Lin C.-S.,National Synchrotron Radiation Research Center | Chiang D.-Y.,National Cheng Kung University
Computers and Structures | Year: 2013

The topic of this paper is the estimation of modal parameters from nonstationary ambient vibration data by applying the random decrement algorithm. If the ambient excitation can be modeled as a nonstationary white noise in the form of a product model, then the nonstationary cross randomdec signatures of structural response evaluated at any fixed time instant are shown theoretically to be proportional to the nonstationary cross-correlation functions, which is of the same form as the free-vibration decay or impulse response of the original system. The practical problem of insufficient data samples available for evaluating nonstationary randomdec signatures can be approximately resolved by first extracting the amplitude-modulating function from the response and then transforming the nonstationary responses into stationary ones. However, the error involved in the approximate free-decay response would generally lead to a distortion in the modal identification. In the present paper, we also further propose that, if the ambient excitation can be modeled as a zero-mean nonstationary process, without any additional treatment of transforming the original nonstationary responses, the nonstationary cross randomdec signatures of structural response are shown in the same mathematical form as that of free vibration of a structure, from which modal parameters of the original system can thus be identified. Numerical simulations, including one example of using the practical excitation data, confirm the validity of the proposed method for identification of modal parameters from nonstationary ambient response data only. © 2013 Elsevier Ltd. All rights reserved. Source


Lei C.U.,California Institute of Technology | Zhang W.-M.,National Cheng Kung University
Annals of Physics | Year: 2012

In this paper, a quantum transport theory for describing photonic dissipative transport dynamics in nanophotonics is developed. The nanophotonic devices concerned in this paper consist of on-chip all-optical integrated circuits incorporating photonic bandgap waveguides and driven resonators embedded in nanostructured photonic crystals. The photonic transport through waveguides is entirely determined from the exact master equation of the driven resonators, which is obtained by explicitly eliminating all the degrees of freedom of the waveguides (treated as reservoirs). Back-reactions from the reservoirs are fully taken into account. The relation between the driven photonic dynamics and photocurrents is obtained explicitly. The non-Markovian memory structure and quantum decoherence dynamics in photonic transport can then be fully addressed. As an illustration, the theory is utilized to study the transport dynamics of a photonic transistor consisting of a nanocavity coupled to two waveguides in photonic crystals. The controllability of photonic transport through the external driven field is demonstrated. © 2012 Elsevier Inc. Source


Liu Y.-C.,National Cheng Kung University
IEEE International Conference on Intelligent Robots and Systems | Year: 2013

This paper presents system framework and control algorithm that enable a human operator to simultaneously interact with a group of swarm robots in a remote environment. In this control system, several characteristics of the configuration of the swarm robots are encoded as task functions, for which a human operator can specify desired values that are conveyed to the end-effector of the master robot. Stability and tracking performance of the proposed control system are investigated in the presence of communication delays so that the swarm robots can be manipulated remotely. Moreover, the swarm robots, which perform like a redundant robotic system, can also regulate their position to achieve secondary tasks autonomously. The proposed control algorithms are validated via numerical simulations on a 3-DOF robot manipulator with a group of mobile robots. © 2013 IEEE. Source


Lin L.-Y.,National Cheng Kung University
PLoS ONE | Year: 2014

Background: To date, few recent studies have investigated the quality of life of adults with autism spectrum disorder (ASD). It remains unclear how individuals with ASD view their own quality of life.Objective: The primary purpose of this study was to compare the quality of life scores among adults with ASD with those of a non-ASD control group and the Taiwanese health population reference group.Methods: The study comprised 41 adults with ASD (M age = 26.9, SD = 5.0), and without intellectual disabilities (IQ>70). A comparison sample of 41 adults without ASD was selected by matching the age and sex of the participants with ASD. A validated measure, the Taiwanese version of the World Health Organization Quality of Life-BREF (WHOQOL-BREF), was used. Independent t-tests were performed to examine the differences in the quality of life between groups. © 2014 Ling-Yi Lin.Results: The highest quality of life was scored in the environment domain, followed by the physical health and psychological health domains. The lowest quality of life score was found in the social relationship domain. Adults with ASD scored significantly lower in all domains than did the non-ASD control group. Additionally, adults with ASD scored significantly lower in the physical health, psychological health, and social relationship domains than did the Taiwanese health population reference group. Comorbid psychiatric disorders, self-rated health status, and perceived happiness were correlated with quality of life among adults with ASD.Conclusion: The preliminary findings suggest that adults with ASD need more supportive social contexts and interventions to promote their quality of life. Based on our findings, social relationship must be considered in designing and applying treatment programs for adults with ASD. © 2014 Ling-Yi Lin. Source


The causal relationships among marine energy consumption, greenhouse gas emissions from international shipping, and economic growth for Kyoto Protocol Annex I countries for the period of 1990 to 2006 are discussed. The real gross domestic product is used as a proxy for economic activity. The United States is also discussed because it was the main global polluter before 2006. The co-integration methodology and an error-correction model are used to examine the causal relationships. The empirical results show that marine energy consumption and GDP are the main factors of increased GHG emissions in the short-run, and that economic activity significantly increased emissions in the long-run. Emissions from shipping are more closely related to marine energy consumption than to economic activity. Hence, policies for mitigating greenhouse gas emissions from marine shipping need to focus on greater energy efficiency in the design of ship engines and hulls. © 2011 Elsevier Ltd. Source


Chang S.-C.,National Cheng Kung University
International Journal of Modern Physics B | Year: 2012

We study the number of acyclic orientations on the generalized two-dimensional Sierpinski gasket SG 2,b(n) at stage n with b equal to two and three, and determine the asymptotic behaviors. We also derive upper bounds for the asymptotic growth constants of SG 2,b and d-dimensional Sierpinski gasket SG d. © 2012 World Scientific Publishing Company. Source


Law S.S.C.,National Cheng Kung University | McDonald K.L.,University of Sydney
International Journal of Modern Physics A | Year: 2014

The complexity of radiative neutrino-mass models can be judged by: (i) whether they require the imposition of ad hoc symmetries, (ii) the number of new multiplets they introduce and (iii) the number of arbitrary parameters that appear. Considering models that do not employ new symmetries, the simplest models have two new multiplets and a minimal number of new parameters. With this in mind, we search for the simplest models of radiative neutrino mass. We are led to two models, containing a real scalar triplet and a charged scalar doublet (respectively), in addition to the charged singlet scalar considered by Zee [h+∼(1, 1, 2)]. These models are essentially simplified versions of the Zee model and appear to be the simplest models of radiative neutrino mass. However, despite successfully generating nonzero masses, present-day data is sufficient to rule these simple models out. The Zee and Zee-Babu models therefore remain as the simplest viable models. Moving beyond the minimal cases, we find a new model of two-loop masses that employs the charged doublet Φ∼(1, 2, 3) and the doubly-charged scalar k++∼(1, 1, 4). This is the sole remaining model that employs only three new noncolored multiplets. © 2014 World Scientific Publishing Company. Source


Huang W.-H.,National Cheng Kung University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

The generalized gravitational entropy proposed recently by Lewkowycz and Maldacena is extended to the interacting real scalar field and Maxwell field system. Using the BTZ geometry we first investigate the case of free real scalar field and then show a possible way to calculate the entropy of the interacting scalar field. Next, we investigate the Maxwell field system. We exactly solve the wave equation and calculate the analytic value of the generalized gravitational entropy. We also use the Einstein equation to find the effect of backreaction of the Maxwell field on the area of horizon. The associated modified area law is consistent with the generalized gravitational entropy. © 2014 The Author. Source


Huang S.-C.,Kuo General Hospital | Yang Y.-J.,National Cheng Kung University
Journal of Pediatric Gastroenterology and Nutrition | Year: 2013

OBJECTIVES:: Nonalcoholic fatty liver disease (NAFLD) is identified as a major liver disease in children. The present study aimed to identify the prevalence and predictors of pediatric NAFLD and the correlation between serum retinol-binding protein 4 (RBP4) levels and metabolic characteristics in children. METHODS:: A total of 748 schoolchildren, ages 6 to 12 years, were enrolled in 2009. The body weight and height were measured in the morning before intake. Laboratory tests included overnight fasting serum lipids, insulin, liver enzymes, and RBP4 levels. Hepatic steatosis was determined by ultrasound in 219 volunteers. RESULTS:: The rates of NAFLD were 3% in the normal-weight, 25% in the overweight, and 76% in the obese children. Twenty (22%) of obese children had abnormal alanine aminotransferase (ALT) levels. In children with NAFLD, younger age and higher body mass index (BMI), insulin/homeostasis model of assessment, and male sex rate were associated with abnormal liver function. Stepwise increments in BMI, insulin, homeostasis model of assessment, and ALT were found in children with normal livers to simple steatosis, and to steatosis with abnormal ALT. Multiple logistic regression analysis confirmed that serum RBP4 levels (P = 0.048), ALT (P = 0.048), and BMI (P < 0.001) were independently predictors of pediatric NAFLD. Moreover, multiple linear regression analysis revealed that only serum triglycerides levels were positively related to RBP4 levels (P < 0.001). CONCLUSIONS:: Higher RBP4 and ALT levels as well as BMI are independently associated with pediatric NAFLD in Taiwan. In addition, an increment in RBP4 levels was positively correlated to hypertriglyceridemia in children. Copyright © 2013 by ESPGHAN and NASPGHAN. Source


Sou S.-I.,National Cheng Kung University
IEEE Transactions on Vehicular Technology | Year: 2013

The Third-Generation Partnership Project (3GPP) has recently standardized the policy and charging control (PCC) system to provide dynamic policy enforcement for network resource allocation combined with real-time charging. The upward trend in smartphone use and the subsequent explosion of data traffic on third-generation (3G) networks have pressed carriers to offload the data traffic from the cellular domain. One key challenge is to elaborate on PCC functionality and mobility management for offloading sessions. This paper proposes an enhanced Wi-Fi offloading model to bring mobile Internet Protocol (IP) integration to a core network with PCC. Specifically, we develop a comprehensive analytical model to quantify the performance of data offloading concerning the amount of 3G resources saved by offloading and the deadline assurance for measuring the quality of user experience with PCC support. Numerical results demonstrate that deadline assurance can be satisfied while saving a significant amount of 3G resources in many situations. © 2013 IEEE. Source


Lai C.-F.,National Ilan University | Chao H.-C.,National Ilan University | Lai Y.-X.,National Cheng Kung University | Wan J.,South China University of Technology
IEEE Wireless Communications | Year: 2013

With the increasing trend for hand-held devices, such as the intelligent mobile phone and tablet PC, users have an increasing demand for network media streaming service. However, in the course of streaming media, the unstable network bandwidth often causes frozen play or delay to degrade user experience. A cloudassisted real-time transcoding mechanism is proposed in this paper, which contains HTTP live streaming protocol, a coding mode transition state machine, and three bandwidth evaluations of error patterns. In the proposed mechanism, the variance in current network is able to be observed according to the bandwidth evaluation results; if different transcoding strategies are used in different modes, the appropriate media segment bit rate is able to be calculated, which is transcoded into the segment to meet the current bandwidth conditions, it makes the users can obtain appropriate media quality automatically through the HTTP redirection technique. Using cloud computing the user will take different transrating media clips into different transrators according to the users' needs, using this technology to increase the transrating efficiency to achieve real-time transrating. Finally, the peak signal-to-noise ratio (PSNR) and bandwidth utilization rate are analyzed as the reference index of improvement in media quality. According to the experimental results, the PSNR can be increased by about 2.8 dB in general network behavior, and the bandwidth utilization rate can be maintained above 80 percent during streaming. © 2013 IEEE. Source


Chou C.-Y.,Fu Jen Catholic University | Ma M.-C.,National Cheng Kung University | Yang T.-T.,National Defense Medical Center
Schizophrenia Research | Year: 2014

Purpose: To identify the determinants of schizophrenia-specific HRQoL levels, five types of factors (i.e., sociodemographic, clinical, psychopathological, neurocognitive, and psychosocial factors) were simultaneously investigated in the same cross-sectional sample. Methods: A total of 120 patients with a diagnosis of schizophrenia but not spectrum conditions were recruited by convenience sampling. Subjective HRQoL levels were measured using the disease-specific S-QoL-C. After sociodemographic and clinical data were collected, psychopathological data were self-rated with the Beck Depression Inventory-II (BDI-II) and were assessed with the Positive and Negative Syndrome Scale (PANSS) by professionally trained raters. Two neurocognitive assessments were conducted by licensed occupational therapists (OTs). Psychosocial factors were assessed using self-reports measures, including the, General Self-Efficacy Scale (GSES), Rosenberg Self-Esteem Scale (RSES), and Social Impact Scale (SIS). All measures were administered in random order. OTs, PANSS raters, and participants were blinded to score computation, and multiple hierarchical regression with the stepwise method was conducted. Results: The S-QoL-C scores were most strongly affected by psychosocial factors and the psychopathological factors, followed by clinical and sociodemographic factors. Total scores on the BDI-II had the largest contributions to S-QoL-C index scores and seven of eight S-QoL-C subscales. In addition, the GSES, RSES, and SIS showed effects across the S-QoL-C subscales. The BDI-II, GSES, and RSES all influenced the S-QoL-C index scores, in addition to the number of hospitalizations. Conclusion: Psychosocial factors and psychopathological factors measured by the BDI-II had the greatest impact on schizophrenia-specific HRQoL levels. Psychiatric treatment programs focusing on psychosocial status and depressive symptoms can improve schizophrenia-specific HRQoL levels. © 2014 Elsevier B.V. Source


Xia P.,Qualcomm | Liu C.-H.,National Cheng Kung University | Andrews J.G.,University of Texas at Austin
IEEE Transactions on Wireless Communications | Year: 2013

Coordinated multi-point (CoMP) communication is attractive for heterogeneous cellular networks (HCNs) for interference reduction. However, previous approaches to CoMP face two major hurdles in HCNs. First, they usually ignore the inter-cell overhead messaging delay, although it results in an irreducible performance bound. Second, they consider the grid or Wyner model for base station locations, which is not appropriate for HCN BS locations which are numerous and haphazard. Even for conventional macrocell networks without overlaid small cells, SINR results are not tractable in the grid model nor accurate in the Wyner model. To overcome these hurdles, we develop a novel analytical framework which includes the impact of overhead delay for CoMP evaluation in HCNs. This framework can be used for a class of CoMP schemes without user data sharing. As an example, we apply it to downlink CoMP zero-forcing beamforming (ZFBF), and see significant divergence from previous work. For example, we show that CoMP ZFBF does not increase throughput when the overhead channel delay is larger than 60% of the channel coherence time. We also find that, in most cases, coordinating with only one other cell is nearly optimum for downlink CoMP ZFBF. © 2002-2012 IEEE. Source


A spatially autocorrelated effect exists in precipitation of a mountainous basin. This study examines the relationship between maximum annual rainfall and elevation in the Kaoping River Basin of southern Taiwan using spatial regression models (i.e. geographically weighted regression (GWR), simultaneous autoregression (SAR), and conditional autoregression (CAR)). Results show that the GWR, SAR, and CAR models can improve spatial data fitting and provide an enhanced estimation for the rainfall-elevation relationship than the ordinary least squares approach. In particular, GWR achieves the most accurate estimation, and SAR and CAR achieve similar performance in terms of the Akaike information criterion. The relationship between extreme rainfall and elevation for longer duration is more concise than that for short durations. Results show that the spatial distribution of precipitation depends on elevation and that rainfall patterns in study area are heterogeneous between the southwestern plain and the eastern mountain area. © 2011 John Wiley & Sons, Ltd. Source


Shiau J.-T.,National Cheng Kung University | Wu F.-C.,National Taiwan University
Water Resources Research | Year: 2013

For reservoirs that are operated for multiple purposes such as water supply, flood control, and power generation, any attempts to incorporate environmental flow targets in the reservoir operation rules need to take into account both the human and ecosystem demands. To date, however, none of the reservoir operation schemes that consider environmental flow requirements includes subdaily flow regimes and is able to optimize for multiple reaches. Here, we address the temporal and spatial issues associated with the optimal environmental flow and operation strategies for a multipurpose reservoir system in Taiwan. We propose an environmental flow proportion strategy and three-period release approach, and multireach operation scenarios that simultaneously optimize reservoir performances and environmental flow objectives at subdaily to interannual timescales for a maximum of three connected reaches. Our results imply that taking into account the environmental flow objectives does not necessarily degrade the overall reservoir performance due to the positive effect on flood control, which in turn would compensate for the adverse effects on domestic water supply and hydropower generation. The three-period release approach benefits mainly the subdaily flow regime, while the environmental flow proportion strategy benefits primarily the daily flow regime. Spatially, a mutual exclusion is observed between the reaches above and below a diversion weir, a fact that revises the conventional perception that restoring the flow regimes of a downstream reach would automatically restore those of upstream reaches. An overall evaluation reveals that the three-reach scenario outperforms the two-reach scenarios, which then outperform the one-reach scenarios. The one- or two-reach scenario that incorporates the midstream reach may be taken as an alternative because such scenario would benefit the upstream or downstream reach in addition to the midstream reach. © 2013. American Geophysical Union. All Rights Reserved. Source


Juang J.-C.,National Cheng Kung University
IEEE Transactions on Automatic Control | Year: 2013

The technical note proposes the use of the generalized cyclic pursuit control strategy for distributed control of a set of agents to render global formation patterns that are characterized in terms of epicyclic motions. By investigating the root distribution of the generalized cyclic pursuit control system, a unique configuration with multiple imaginary-axis eigenvalues is identified. Design criteria to achieve such a configuration are delineated. The design leads to a class of epicyclic trajectories for agents and, as a result, a class of patterns can be established to serve the purpose of cooperative tracking, area surveillance, and exploration. © 1963-2012 IEEE. Source


Bando M.,New York University | Lin Y.-L.,National Cheng Kung University | Chao H.J.,New York University
IEEE/ACM Transactions on Networking | Year: 2012

It is becoming apparent that the next-generation IP route lookup architecture needs to achieve speeds of 100 Gb/s and beyond while supporting IPv4 and IPv6 with fast real-time updates to accommodate ever-growing routing tables. Some of the proposed multibit-trie-based schemes, such as TreeBitmap, have been used in today's high-end routers. However, their large data structures often require multiple external memory accesses for each route lookup. A pipelining technique is widely used to achieve high-speed lookup with the cost of using many external memory chips. Pipelining also often leads to poor memory load-balancing. In this paper, we propose a new IP route lookup architecture called FlashTrie that overcomes the shortcomings of the multibit-trie-based approaches. We use a hash-based membership query to limit off-chip memory accesses per lookup and to balance memory utilization among the memory modules. By compacting the data structure size, the lookup depth of each level can be increased. We also develop a new data structure called Prefix-Compressed Trie that reduces the size of a bitmap by more than 80%. Our simulation and implementation results show that FlashTrie can achieve 80-Gb/s worst-case throughput while simultaneously supporting 2 M prefixes for IPv4 and 318 k prefixes for IPv6 with one lookup engine and two Double-Data-Rate (DDR3) SDRAM chips. When implementing five lookup engines on a state-of-the-art field programmable gate array (FPGA) chip and using 10 DDR3 memory chips, we expect FlashTrie to achieve 1-Gpps (packet per second) throughput, equivalent to 400 Gb/s for IPv4 and 600 Gb/s for IPv6. FlashTrie also supports incremental real-time updates. © 2012 IEEE. Source


Jeng D.J.-F.,National Cheng Kung University | Tzeng G.-H.,National Chiao Tung University | Tzeng G.-H.,Kainan University
Computers and Industrial Engineering | Year: 2012

The aim of study is to examine whether social influence affects medical professionals' behavioral intention to use while introducing a new Clinical Decision Support System (CDSS). The series of Technology Acceptance Models (TAMs) have been widely applied to examine new technology acceptance by scholars; nevertheless, these models omit system diversity and the user's profession. On the other hand, causal analysis greatly affects the efficiency of decision-making, and it is usually analyzed by Structural Equation Modeling (SEM); however, the method is often misapplied. This research applies the Decision-Making Trial and Evaluation Laboratory (DEMATEL) technique to explore the causal relationship between the significant Unified Theory of Acceptance and Use of Technology (UTAUT) variables. Fuzzy concept is applied to illustrate human vague judgment. It is significant that, in contrary with UTAUT, this study found that social influence does not matter in the behavioral intention to use the CDSS for medical professionals. © 2011 Elsevier Ltd. All rights reserved. Source


Yang L.-S.,Far East University of Taiwan | Liang T.-J.,National Cheng Kung University
IEEE Transactions on Industrial Electronics | Year: 2012

A novel bidirectional dc-dc converter is presented in this paper. The circuit configuration of the proposed converter is very simple. The proposed converter employs a coupled inductor with same winding turns in the primary and secondary sides. In step-up mode, the primary and secondary windings of the coupled inductor are operated in parallel charge and series discharge to achieve high step-up voltage gain. In step-down mode, the primary and secondary windings of the coupled inductor are operated in series charge and parallel discharge to achieve high step-down voltage gain. Thus, the proposed converter has higher step-up and step-down voltage gains than the conventional bidirectional dc-dc boost/buck converter. Under same electric specifications for the proposed converter and the conventional bidirectional boost/buck converter, the average value of the switch current in the proposed converter is less than the conventional bidirectional boost/buck converter. The operating principle and steady-state analysis are discussed in detail. Finally, a 14/42-V prototype circuit is implemented to verify the performance for the automobile dual-battery system. © 2011 IEEE. Source


In recent years, the family of multicarrier code-division multiple-access (MC-CDMA) transmission technologies has drawn a lot of attention in providing broadband wireless communication services. From the literature, one can find extensive discussions in many aspects of MC-CDMA under a flat system architecture either for conventional or currently emerging cognitive radio (CR) systems. In this paper, we shift the focus from the flat architecture to the hierarchical architecture based on 2-D-spread multicarrier direct-sequenced CDMA, in which a microcell is embedded in the primitive macrocell. However, in such a hierarchical architecture, severe intercell interference can occur between the macrocell and the microcell. Via the interference avoidance code assignment strategy, this kind of intercell interference in downlink transmissions can be eliminated. To this end, we define the white, gray, and black spreading codes to facilitate the management of spreading code resources. Properly allocating the white and gray spreading codes but the black ones can achieve a higher spectrum efficiency without harming the macrocell users. For the purpose of evaluating the candidacy of the gray spreading codes, a sophisticated interference analysis is conducted to define a new multiple access interference (MAI) coefficient to quantize the amount of interference imposed on a microcell user. With the help of the new MAI coefficient, a less-interfered white or gray spreading code can be assigned to microcell users, which can bring about an extra 55% of call admissions in one of our considered cases. Moreover, the capability of the proposed hierarchical system architecture, as well as the interference management scheme for developing the femtocell system, has also been proved via simulation results with a large number of femtocells. It is believed that by cooperating with the substream deactivation technique, the proposed spreading code management associated with the hierarchical system architecture can be a potential prototype of the CR-based femtocell system. © 2011 IEEE. Source


Cheng Y.-C.,Tainan University of Technology | Li S.-T.,National Cheng Kung University
IEEE Transactions on Fuzzy Systems | Year: 2012

Since its emergence, the study of fuzzy time series (FTS) has attracted more attention because of its ability to deal with the uncertainty and vagueness that are often inherent in real-world data resulting from inaccuracies in measurements, incomplete sets of observations, or difficulties in obtaining measurements under uncertain circumstances. The representation of fuzzy relations that are obtained from a fuzzy time series plays a key role in forecasting. Most of the works in the literature use the rule-based representation, which tends to encounter the problem of rule redundancy. A remedial forecasting model was recently proposed in which the relations were established based on the hidden Markov model (HMM). However, its forecasting performance generally deteriorates when encountering more zero probabilities owing to fewer fuzzy relationships that exist in the historical temporal data. This paper thus proposes an enhanced HMM-based forecasting model by developing a novel fuzzy smoothing method to overcome performance deterioration. To deal with uncertainty more appropriately, the roulette-wheel selection approach is applied to probabilistically determine the forecasting result. The effectiveness of the proposed model is validated through real-world forecasting experiments, and performance comparison with other benchmarks is conducted by a Monte Carlo method. © 2012 IEEE. Source


BACKGROUND: Combined radiotherapy and chemotherapy is considered the standard of care for locally advanced nasopharyngeal carcinoma (LA-NPC) in Epstein-Barr virus infection endemic area. This study compared the long-term outcomes between LA-NPC patients treated with neoadjuvant chemotherapy followed by radiotherapy (NACT) and those treated with concurrent chemoradiotherapy (CCRT).METHODS: From 2003 to 2007, a total of 128 histopathologically proven LA-NPC patients receiving either NACT or CCRT were consecutively enrolled at the National Cheng Kung University Hospital in Taiwan. NACT consisted of 3-week cycles of mitomycin, epirubicin, and cisplatin on day 1 and fluorouracil and leucovorin on day 8 (MEPFL) or weekly alternated cisplatin on day 1 and fluorouracil and leucovorin on day 8 (P-FL). CCRT comprised 3-week cycles of cisplatin (Cis 100) or 4-week cycles of cisplatin and fluorouracil (PF4). The first failure site, disease free survival (DFS), overall survival (OS), and other prognostic factors were analyzed.RESULTS: Thirty-eight patients (30%) received NACT. Median follow-up duration was 53 months. More patients with advanced nodal disease (N2-N3) (86.8% vs 67.8%, p =0.029) and advanced clinical stage (stage IVA-IVB) enrolled in the NACT group (55.2% vs 26.7%, p =0.002). For NACT, both MEPFL and P-FL had similar 5-year DFS and OS (52.9% vs 50%, p =0.860 and 73.5% vs 62.5%, p =0.342, respectively). For CCRT, both PF4 and Cis 100 had similar 5-year DFS and OS (62.8% vs 69.6%, p =0.49 and 72.9% vs 73.9%, p =0.72, respectively). Compared to CCRT, NACT had similar 5-year DFS and OS (51.5% vs 65.1%, p =0.28 and 71.7% vs 74.3%, p =0.91, respectively). Among patients who were recurrence-free in the first 2 years after treatment, those treated with NACT experienced poorer locoregional control compared to those treated with CCRT (Hazard ratio =2.57, 95% confidence interval: 1.02 to 6.47, p =0.046).CONCLUSIONS: For LA-NPC, both CCRT and NACT were similarly efficacious treatment strategies in terms of long-term disease control and survival probability. Close locoregional follow-up is recommended for patients receiving NACT, because these patients are more prone to develop locoregional failure than patients receiving CCRT. Source


Chen Y.-J.,National Kaohsiung First University of Science and Technology | Chen Y.-M.,National Cheng Kung University
Knowledge-Based Systems | Year: 2012

Capable of providing an interactive platform for enterprise experts to create and share empirical knowledge cooperatively, professional virtual communities have arisen from the pervasive use of the Internet. This circumstance incurs an overload of information and overflow of spam messages, accounting for high-volume low-quality knowledge in virtual communities. Therefore, providing valid knowledge decision support in order to assist community members to accurately predict and supply required empirical knowledge is of priority concern in implementing tacit knowledge management in an enterprise. This work develops a technology for knowledge evolution course discovery in a professional virtual community as a decision support mechanism to discover effectively the empirical knowledge evolution course hidden inside of a professional virtual community, which can guide community members to retrieve required empirical knowledge quickly. This objective can be obtained by performing the following tasks: (i) design of an empirical knowledge management framework for professional virtual communities, (ii) definition of a knowledge evolution course model, (iii) design of a knowledge evolution course discovery process, (iv) development of techniques related to the technology for knowledge evolution course discovery, and (v) implementation and evaluation of a knowledge evolution course discovery mechanism for professional virtual communities. In developing techniques associated with the discovery of knowledge evolution course, which involves topic classification, domain dictionary construction, ontology-based topic empirical knowledge model construction, topic concept extraction and representation, and path establishment between topic concepts. © 2012 Elsevier B.V. All rights reserved. Source


Chung C.-C.,University of Manchester | Chung C.-C.,National Cheng Kung University
Research Policy | Year: 2013

This article focuses on the research of RTDI policies (research, technology, development and innovation), and the theme of this article is to link the three indicators together: RTDI policy-making process - the contents of RTDI policies - the appropriateness of RTDI policies on the configuration of the national, the sectoral and the technological innovation systems. We define the configuration of the three innovation systems as national, sectoral and technological innovation system (NSTIS). We assume the policy-making process of RTDI policies would shape the contents of RTDI policies. Once the contents of RTDI policies are implemented, the RTDI policies would influence, whether appropriate or inappropriate, on the NSTIS. We use the Taiwanese pharmaceutical biotechnology policies as empirical cases. On the basis of the empirical cases of Taiwan, we find that the consistency and appropriateness of RTDI policies are shaped by four variables: polity, horizontal coordination, vertical coordination and the involvement of external stakeholders. The policy-making process indeed shapes the RTDI policies which further shape the development of NSTIS. © 2013 Elsevier B.V. All rights reserved. Source


Law S.S.C.,National Cheng Kung University | McDonald K.L.,University of Sydney
Journal of High Energy Physics | Year: 2013

We present a class of models with radiative neutrino mass and stable dark-matter candidates. Neutrino mass is generated by a one-loop diagram with the same topography as Ma's 2006 proposal (which used an inert scalar-doublet and singlet fermion). We generalize this approach and determine all variants with new fields no larger than the adjoint representation. When the neutrino mass diagram contains a Majorana mass insertion there are two possibilities, both of which are known. If the mass insertion is of the Dirac type there are seven additional models, two of which are excluded by direct-detection experiments. The other five models are also constrained, such that only scalar dark-matter is viable. There are cases with an inert singlet, an inert doublet, and an inert triplet, providing a natural setting for inert N -tuplet models of dark matter, with the additional feature of achieving radiative neutrino mass. We show that some of the models admit a simple explanation for the (requisite) discrete symmetry, and briefly discuss cases with representations larger than the adjoint, which can admit a connection to the astrophysical gamma-ray signal. © 2013 SISSA, Trieste, Italy. Source


Lu J.-J.,Tainan University of Technology | Chen W.-H.,National Cheng Kung University
Applied Energy | Year: 2015

Ignition and burnout temperatures are important properties of solid fuels for their applications in industry. In this study, the thermogravimetric analyses (TGA) of bamboo and sugarcane bagasse at five different heating rates of 5, 10, 20, 30, and 40°Cmin-1 are performed. The intersection method (IM) and deviation method (DM) are employed to approach the ignition temperatures of the two biomass species, while IM and the conversion method (CM) are adopted to analyze their burnout temperatures. In IM and CM, both the ignition and burnout temperatures increase with increasing heating rate, as a consequence of the pronounced thermal lag in biomass particles at high heating rates. The measured ignition temperatures based on DM are lower than those based on IM, and there is no correlation between the temperature and heating rate. The determined burnout temperatures from IM are close to those obtained from CM, while the difference in the burnout temperatures of the two biomass samples is small. The ignition temperatures of the two biomass species measured from IM are between 250 and 300°C, and their burnout temperatures are close to 500°C. As a whole, IM is recommended for determining the ignition temperature of biomass, while CM is a feasible and simple route to approach the burnout temperature. The heating rates in TGA between 20 and 30°Cmin-1 are suggested because of their accurate and time-saving operations. © 2015 Elsevier Ltd. Source


Ogawa R.,Nippon Medical School | Hsu C.-K.,National Cheng Kung University
Journal of Cellular and Molecular Medicine | Year: 2013

During growth and development, the skin expands to cover the growing skeleton and soft tissues by constantly responding to the intrinsic forces of underlying skeletal growth as well as to the extrinsic mechanical forces from body movements and external supports. Mechanical forces can be perceived by two types of skin receptors: (1) cellular mechanoreceptors/mechanosensors, such as the cytoskeleton, cell adhesion molecules and mechanosensitive (MS) ion channels, and (2) sensory nerve fibres that produce the somatic sensation of mechanical force. Skin disorders in which there is an abnormality of collagen [e.g. Ehlers-Danlos syndrome (EDS)] or elastic (e.g. cutis laxa) fibres or a malfunction of cutaneous nerve fibres (e.g. neurofibroma, leprosy and diabetes mellitus) are also characterized to some extent by deficiencies in mechanobiological processes. Recent studies have shown that mechanotransduction is crucial for skin development, especially hemidesmosome maturation, which implies that the pathogenesis of skin disorders such as bullous pemphigoid is related to skin mechanobiology. Similarly, autoimmune diseases, including scleroderma and mixed connective tissue disease, and pathological scarring in the form of keloids and hypertrophic scars would seem to be clearly associated with the mechanobiological dysfunction of the skin. Finally, skin ageing can also be considered as a degenerative process associated with mechanobiological dysfunction. Clinically, a therapeutic strategy involving mechanoreceptors or MS nociceptor inhibition or acceleration together with a reduction or augmentation in the relevant mechanical forces is likely to be successful. The development of novel approaches such as these will allow the treatment of a broad range of cutaneous diseases. © 2013 The Authors. Source


Su W.R.,National Cheng Kung University
Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association | Year: 2013

The purpose of this biomechanical study was to compare the ultimate failure strength, stiffness, cyclic displacement, and failure displacement of 5 different proximal biceps tenodesis fixation techniques, specifically comparing wedge tenodesis with the other 4 techniques. Forty cadaveric shoulders underwent 1 of 5 long head of the biceps tenodesis techniques and were cyclically tested to failure by use of tensile forces applied parallel to the longitudinal axis of the humerus. A preload at 5 N was applied for 2 minutes, followed by cyclical loading for 500 cycles from 5 to 70 N at 1 Hz and a pull-to-failure test at 1 mm/s. The techniques studied were wedge tenodesis, suture anchor fixation, suprapectoral interference screw fixation, T-wedge tenodesis, and the percutaneous intra-articular transtendon (PITT) technique. Cyclic displacement, failure displacement, and stiffness were calculated. The wedge tenodesis technique had an ultimate failure load similar to interference screw fixation and a greater ultimate failure load and stiffness than the suture anchor, PITT, and T-wedge techniques (P < .05). In this biomechanical study, wedge tenodesis was found to have an ultimate failure load similar to interference screw fixation and a greater ultimate failure load and stiffness than the suture anchor, PITT, and T-wedge techniques. On biomechanical testing, wedge tenodesis compares favorably with other techniques and may be a useful clinical option for proximal biceps tenodesis. Copyright © 2013 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved. Source


Chen W.-H.,National University of Tainan | Lu K.-M.,National Cheng Kung University | Tsai C.-M.,National University of Tainan
Applied Energy | Year: 2012

Three agricultural wastes, consisting of coffee residue, sawdust and rice husk, undergoing torrefaction are investigated to evaluate the potential of biomass as solid fuel. Two different torrefaction temperatures (240 and 270°C) and durations (0.5 and 1h) are considered in the study, and the properties and structures of the raw and torrefied wastes are extensively investigated by means of proximate, elemental, fiber, calorific, thermogravimetric, SEM and FTIR analyses. A high-volatile bituminous coal and a low-volatile one are also regarded for comparison. By virtue of more hemicellulose contained in the coffee residue, it is the most active biomass to torrefaction and its higher heating value (HHV) is improved up to 38%. The empirical atomic formula of the raw wastes is expressed by CH1.54-1.76O0.65-0.89 and it changes to CH1.02-1.57O0.26-0.64 after undergoing torrefaction. The torrefied biomasses approach high-volatile coal when the torrefaction temperature and duration increase. From fuel point of view, the improved properties and changed molecular structure are conducive to the applications of biomass in industrial furnaces such as boilers and blast furnaces. © 2012 Elsevier Ltd. Source


Chow H.-W.,National Cheng Kung University
BMC Public Health | Year: 2013

Background: The growing amount of outdoor fitness equipment (OFE) placed in parks in many countries has the intent of encouraging physical activity among aging populations. However, little investigated aspects are the perceptions and experiences of older adults regarding the use of these facilities. Hence, this study seeks senior OFE users' opinions to understand the exact nature of use of these facilities, the perceived health benefits achieved, and equipment's improvements that would further encourage use. Methods. The study conducts semi-structured interviews with 55 senior OFE users at two parks in Taiwan. Results: Study results suggest that although OFE use is not the main purpose for which seniors visit parks, most seniors perceive the benefit of using OFE in terms of both physical and psychological health, as well as social connection. Respondents also raised issues related to safety, maintenance, and management of OFE. Conclusions: OFE appears to meet the health needs of seniors, but improved management is necessary to ensure safety. Further research would reveal the actual behavior involving OFE use and use's relationship to the physical activity of seniors. © 2013 Chow; licensee BioMed Central Ltd. Source


Juang J.-C.,National Cheng Kung University
Proceedings of the IEEE Conference on Decision and Control | Year: 2012

The paper investigates the formation patterns for a group of double-integrator agents in cyclic pursuit. It is shown that under distributed position and velocity feedback control, the agents may experience rendezvous, elliptical, and spiral patterns depending on the distribution of roots. By introducing a rigidity term in the control strategy, a new class of epicyclic motions can be created. The epicyclic motions may be advantageous in target tracking and surveillance applications. © 2012 IEEE. Source


Chen C.-H.,National Cheng Kung University | Nomura T.,Korea Institute for Advanced Study
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

Diboson resonance with mass of 1.8-2 TeV is reported successively by CMS and ATLAS experiments in proton-proton collisions at s=8 TeV. We investigate the potentiality of Higgs singlet as the TeV resonance. The challenges of low production cross section and high width for a fundamental scalar could be got over by three factors: (1) larger Yukawa couplings, (2) larger number of heavy quarks and (3) smaller mixing angle with standard model Higgs. We find that the required factors could be realized in the framework of two vectorlike triplet quarks (VLTQs) and the resulting production cross section and decay fraction of heavy Higgs σ(pp→H)×BR(H→W+W-+ZZ) can be of O(10) fb when masses of new heavy quarks are 1 TeV, the values of Yukawa couplings are around 3 and the mixing angle is sinθ∼0.11. We also find that the SM Higgs production and its decay in the process pp→h→γγ could be still consistent with current data when a color-triplet scalar (3,3)1/3 is considered. Furthermore, we study the product of VLTQ-pair production cross section and the BRs of VLTQ decays, and find that the cross sections in the decay channels, such as u4,5→bW+, d5→tW- and d4→bh(Z) could be 7-17 fb at 13 TeV LHC. © 2015 American Physical Society. Source


Hsu W.-Y.,National Cheng Kung University | Hsu W.-Y.,Academia Sinica, Taiwan
Journal of Neuroscience Methods | Year: 2010

In this paper, a feature extraction method through the time-series prediction based on the adaptive neuro-fuzzy inference system (ANFIS) is proposed for brain-computer interface (BCI) applications. The ANFIS time-series prediction together with multiresolution fractal feature vectors (MFFVs) is applied for feature extraction in motor imagery (MI) classification. The features are extracted from the electroencephalography (EEG) signals recorded from subjects performing left and right MI. Two ANFISs are trained to perform time-series predictions for respective left and right MI data. Features obtained from the difference of MFFVs between the predicted and actual signals are then calculated through a window of EEG signals. Finally, a simple linear classifier, namely linear discriminant analysis (LDA), is used for classification. The proposed method is estimated with classification accuracy and the area under the receiver operating characteristics curve (AUC) on six subjects from two data sets. I also assess the performance of proposed method by comparing it with well-known linear adaptive autoregressive (AAR) model, AAR time-series prediction, and neural network (NN) time-series prediction. The results indicate that ANFIS time-series prediction together with MFFV features is a promising method in MI classification. © 2010 Elsevier B.V. Source


Patent
National Cheng Kung University | Date: 2013-05-29

A pharmaceutical kit for treating neuronal damages is disclosed. The pharmaceutical composition of the present invention comprises: a first pharmaceutical composition comprising a first effective amount of a Mg


An in situ pulse-based delay variation monitor that predicts timing errors caused by process and environmental variations is revealed. The monitor includes a sequential storage device having a mater storage device and a slave storage device, a transition detector that is electrically connected to a node set on an electrical connection pathway from a master storage device to the slave storage device, and a warning signal generator electrically connected to the transition detector. The transition detector receives output of the master storage device to form a warning area by delay buffer, and generates a pulse width output correspondingly according to transition of the data input. Thus the warning signal generator generates a warning signal according to logic action at the pulse width and the clock input when the data input reaches the warning area. Thereby timing errors caused by static process variations and dynamic environmental variations are predicted.


A process for making an article of a titanium alloy having phase as a major phase according to the present invention includes providing a work piece of a titanium alloy consisting essentially of 7-9 wt % of molybdenum and the balance titanium and having phase as a major phase; and cold working at least a portion of the work piece at room temperature to obtain a green body of the article, wherein the cold worked portion of the green body has a thickness which is 20%-80% of that of the at least a portion of the work piece, and the cold worked portion has phase as a major phase.


Patent
National Cheng Kung University | Date: 2013-06-03

A tube fitting includes a multi-way tube member and a coupler. The multi-way tube member includes three interconnected tube-connecting segments, one of which has two locking portions disposed at a distal end thereof. The coupler includes a cap section covering one of the tube-connecting segments having the locking portions, two resilient retaining portions snapped respectively to the locking portions, a guide tube section extending from the cap section into the one of the tube-connecting segments, and a connecting tube section extending from the cap section in a direction away from the guide tube section for connection with an additional coupler. A curable filler can be filled among the multi-way tube member, the coupler, and a tube for fixing the tube within the multi-way tube member.


Grant
Agency: Cordis | Branch: FP7 | Program: CSA-CA | Phase: ENV.2013.6.5-1 | Award Amount: 1.28M | Year: 2013

The greenXpo consortium comprises a balanced group of policy makers, SMEs, multipliers, technical and innovation experts from Belgium, Finland, France, Germany, Italy, Sweden and Taiwan that are strongly committed to boosting the green economy through the greenXpo eco-innovation expertise portal. The consortium is best prepared for this action since it comprises organisations that have already led actions to analyse and promote technological and non-technological eco-innovation, eco-innovative policies as well as networks such as ECO-INNOVERA, ECOPOL, ECO-PRO (INNOVATIONSEEDS) and the Eco-Innovation Observatory. Now, the greenXpo partners are pooling their expertise and experience to promote all types of eco-innovation together in a holistic one-stop shop for eco-innovation. The overall objective of greenXpo is to develop a new and innovative web-based tool, to facilitate knowledge transfer, uptake and exploitation of research data, as well as good policy measures related to eco-innovation, and to proactively promote the quality knowledge to policy makers, enterprises and society at large. To ensure synergies and a speedy implementation, greenXpo will build on the state-of-the-art INNOVATIONSEEDS portal that already features 100 European environmental R&D results. The general objective is broken down into six ambitious, specific objectives: 1) to develop a web-based tool for eco-innovation knowledge; 2) to present 190 new eco-innovation cases in a user-friendly manner to market players, policy makers and society; 3) to develop an analytical framework of successful and unsuccessful eco-innovation and to transfer it to policy makers; 4) to promote cross-sectoral information exchange and spill-overs with five traditional industry sectors; 5) to pro-actively promote the eco-innovation knowledge gathered reaching 2,000 policy makers and 120,000 enterprises in Europe and world-wide; and 6) to develop a business model for the continuation of the greenXpo portal.


A signal process system and the method for the same and a biological resistance detection device and element used to perform corresponding signal process for sensory signal sensed by a sensor, wherein a minor AC electrical signal is injected into a biological tissue to be measured in order to sense the sensory signal of the biological tissue to be measured by means of the principle of Ohms Law. Moreover, the sensory signal may be processed to restore a biological property of the measured biological tissue and to create an equivalent circuit parameter model representative of the biological property.


Patent
National Cheng Kung University | Date: 2013-08-13

A method of reading multiple two dimensional barcodes includes the steps of obtaining an image including a plurality of positioning patterns and the two dimensional barcodes, defining a reading area within the image according the positioning patterns, dividing the reading area into a plurality of reading blocks, which contain the two dimensional barcodes, respectively, and reading the two dimensional barcodes in the reading blocks individually.


Patent
National Cheng Kung University | Date: 2014-06-15

An AC motor with a reduction mechanism is disclosed. The AC motor has a stator unit, a rotor unit, and a reduction transmission unit. An axial space of the AC motor can be substantially reduced by providing the reduction transmission unit directly built in the AC motor, and a path of the power transmission between the rotor unit and an output shaft can be reduced, so that the loss of the mechanical energy can be lowered.


Patent
National Cheng Kung University | Date: 2015-06-12

An all-electric spin field effect transistor is disclosed, which includes an injection node, injecting an electron in a first spin direction; a detection node, detecting the electron in the first spin direction; and a gate, disposed between the injection node and the detection node such that the electron changes from the first spin direction to a second spin direction by carrying out precession; if the second spin direction is parallel to the first spin direction, the electron is able to pass through the detection node; if the second spin direction is antiparallel to the first spin direction, the electron is unable to pass through the detection node.


Patent
National Cheng Kung University | Date: 2013-08-13

A medicine container detachably disposed in an electronic medicine box includes an accommodating portion and a cover portion. The accommodating portion has a medicine containing space. The cover portion is movably connected to accommodating portion and has a barcode. When the medicine container is disposed in the electronic medicine box, the barcode is readable. A medication auxiliary device including a plurality of the above medicine containers and an electronic medicine box is also disclosed.


Patent
National Cheng Kung University | Date: 2014-01-27

A composite electrode and a lithium-based battery are disclosed, wherein the composite electrode comprises: a substrate and a conductive layer formed on the substrate, wherein the conductive layer comprises graphite powders, Si-based powders, Ti-based powders, or a combination thereof embedded in a conductive matrix and coated with diamond films, and the diamond films are formed of diamond grains. The novel electrodes of the present invention when used in the Li-based battery can provide superior performance including excellent chemical inertness, physical integrity, and charge-discharge cycling life-time, and exhibit high electric conductivity and excellent lithium ion permeability.


A baseline predictive maintenance method for a target device (TD) and a computer program product thereof are provided. Fresh samples which are generated when the target device produces workpieces just after maintenance are collected, and a new workpiece sample which is generated when the target device produces a new workpiece is collected. A plurality of modeling samples are used to build a TD baseline model in accordance with a conjecturing algorithm, wherein the modeling samples include the new workpiece sample and the fresh samples. A TD healthy baseline value for the new workpiece is computed by the TD baseline model, and a device health index (DHI), a baseline error index (BEI) and baseline individual similarity indices (ISI