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The National Taiwan University of Science and Technology , commonly referred to as Taiwan Tech, is a public/national technological university located in Taipei, Taiwan. Taiwan Tech was established in 1974, as the first and the leading higher education institution of its kind within Taiwan's technical and vocational education system. The university is ranked 353 among world universities in the Times Higher Education-QS World University Rankings 2013.The university is also ranked 52 among Asian universities in the Times Higher Education-QS World University Rankings 2013. NTUST Taiwan was also ranked as Asia's 10th best institute in science and technology.Taiwan Tech enrolled 5,645 undergraduates and 4,744 graduate students, and employed 414 full-time faculties and about 318 staff members in 2013. The university’s 14 departments and 24 graduate programs are divided into the following 7 colleges, College of Engineering, College of Electrical Engineering and Computer Science, School of Management, College of Design, College of Liberal Arts and Social science, College of Intellectual Property Studies, and Honors College.Taiwan Tech has five campuses, the Gongguan campus, located at 43 Keelung Rd, Sec. 4, situated in the south region of Taipei City, being the main campus covers an area of approximately 10 hectares, while the whole campuses cover up to 44.5 hectares. Wikipedia.


Cheng Y.-M.,China University of Technology | Leu S.-S.,National Taiwan University of Science and Technology
Expert Systems with Applications | Year: 2011

This paper tries to analyze common bridge construction defects, classify them into appropriate groups, and redefine them as a precautionary measure and means to improve quality in bridge construction. For this purpose, data on bridge construction since January 2007 were obtained from the evaluation report of the Public Construction Committee (PCC) of Taiwan. Bridge construction defects were classified according to their characteristics. A constraint-based clustering method and affinity diagram (KJ method) are proposed and used. This method can simultaneously treat mixed data types; moreover, it can incorporate user-specified constraints. The quality or safety issues, the unit-in-charge (Government authorities/project owners/contractor), and the properties of the defects (construction/audit/documents/others) are the sorting attributes. The constraint is avoiding empty clusters or clusters having very few objects. The results revealed five major defect classifications: safety and environment, construction site defects, supervision/control process, construction quality documents, and others. © 2010 Elsevier Ltd. All rights reserved. Source


Pan J.C.-H.,Takming University of Science and Technology | Tai D.H.,National Taiwan University of Science and Technology
Computers and Industrial Engineering | Year: 2011

The defect of process equipments is a major factor that impairs the yields in the mass production of semiconductor wafer fabrication and it is a main supervision means to use high-resolution defect inspection tools to detect and monitor the defect damage. Due to the high investment costs of these inspection tools and the resulting decrease in the throughput, how to improve the sampling rate is an important issue for the associated inspection strategy. This paper proposes a new concept and implementation of virtual inspection (VI) to enhance the detection and monitoring of defect in semiconductor production process. The underlying theory of the VI concept is that the state variables identifications (SVIDs) of process equipments can reflect the process quality effectively and loyally. The approach of VI is to combine the application of the fault detection and classification (FDC), and the defect library and the re-engineering of inspection procedure to reach the full-scope of strategic objective. VI enables the defect monitoring to enter a new era by promoting the monitoring level of defect inspection from the previous lot-sampling basis to the wafer-sampling level, and hence upgrades the sampling strategy from random-sampling to full and right-sampling. In this study, various typical defect cases are utilized to illustrate how to create VI models and verify the reliability of the proposed approach. Furthermore, a feasible architecture of the VI implementation for mass production in semiconductor factory is presented in the paper. © 2010 Elsevier Ltd. All rights reserved. Source


Lin S.-W.,Chang Gung University | Yu V.F.,National Taiwan University of Science and Technology | Lu C.-C.,National Taipei University of Technology
Expert Systems with Applications | Year: 2011

European firms have been using a combination of trucks and trailers in the delivery/collection of food products for years. Thus, some previous studies had been devoted to improving the efficiency of the resulting truck and trailer routing problem (TTRP). Since time window constraints are present in many real-world routing applications, in this study, we introduce the truck and trailer routing problem with time windows (TTRPTW) to bring the TTRP model closer to the reality. A simulated annealing (SA) heuristic is proposed for solving the TTRPTW. Two computational experiments are conducted to test the performance of the proposed SA heuristic. The results indicate that the proposed SA heuristic is capable of consistently producing quality solutions to the TTRPTW within a reasonable time. © 2011 Elsevier Ltd. All rights reserved. Source


Lin Y.-K.,National Taiwan University of Science and Technology
Computers and Industrial Engineering | Year: 2011

The quickest path problem involving two attributes, the capacity and the lead time, is to find a single path with minimum transmission time. The capacity of each arc is assumed to be deterministic in this problem. However, in many practical networks such as computer networks, telecommunication networks, and logistics networks, each arc is multistate due to failure, maintenance, etc. Such a network is named a multistate flow network. Hence, both the transmission time to deliver data through a minimal path and the minimum transmission time through a multistate flow network are not fixed. In order to reduce the transmission time, the data can be transmitted through k minimal paths simultaneously. The purpose of this paper is to evaluate the probability that d units of data can be transmitted through k minimal paths within time threshold T. Such a probability is called the transmission reliability. A simple algorithm is proposed to generate all lower boundary points for (d, T), the minimal system states satisfying the demand within time threshold. The transmission reliability can be subsequently computed in terms of such points. Another algorithm is further proposed to find the optimal combination of k minimal paths with highest transmission reliability. © 2011 Elsevier Ltd. All rights reserved. Source


Chang T.-H.,National Taiwan University of Science and Technology | Hong M.,Iowa State University | Wang X.,East China Normal University
IEEE Transactions on Signal Processing | Year: 2015

Multi-agent distributed consensus optimization problems arise in many signal processing applications. Recently, the alternating direction method of multipliers (ADMM) has been used for solving this family of problems. ADMM based distributed optimization method is shown to have faster convergence rate compared with classic methods based on consensus subgradient, but can be computationally expensive, especially for problems with complicated structures or large dimensions. In this paper, we propose low-complexity algorithms that can reduce the overall computational cost of consensus ADMM by an order of magnitude for certain large-scale problems. Central to the proposed algorithms is the use of an inexact step for each ADMM update, which enables the agents to perform cheap computation at each iteration. Our convergence analyses show that the proposed methods converge well under some convexity assumptions. Numerical results show that the proposed algorithms offer considerably lower computational complexity than the standard ADMM based distributed optimization methods. © 2014 IEEE. Source


Much emphasis has been placed on the research on applying digital games in science education. Among the studies, the advantages and limitations of role-playing simulation games deserve further exploration. However, existing analyses of the behavioral patterns of role-playing simulation games in science education remain substantially lacking, particularly the integration of diverse behavioral pattern analysis methods. This study thus seeks to analyze the videotaped learning process of 86 college students in game-based learning activities that utilize a role-playing simulation game. This study used the integrated method of sequential analysis and cluster analysis and explored the learners' flow state and learning behavioral patterns. The results show that the use of integrated behavioral pattern analysis helps to explore the traits and limitations of role-playing simulation games in science education as well as learners' reflective behavior patterns. This study identifies a wide variety of learning behavior patterns from three potential clusters of learners and then discusses the learning process of each cluster. The different levels of flow experienced by the learners affected their learning behavior patterns; learners with higher levels of flow demonstrated a more in-depth reflective process. The study further discusses the results of these analyses and makes relevant recommendations for the systems development of the games, its educational applications, and evaluation methods. © 2015 Elsevier Ltd. All rights reserved. Source


Kuo Y.-L.,National Taiwan University of Science and Technology
Computers and Mathematics with Applications | Year: 2016

This paper presents a mathematically dynamic model of a Delta robot with flexible links. The mathematical models of the robot cannot be represented by partial differential equations, so this paper utilizes the kineto-elasto-dynamics and the finite element method to perform a mathematical model. Each link of the robot is modeled by multiple beam elements with an axial displacement, an axial torsion, and two transverse displacements. In literature, element assembling usually imposes a set of algebraic constraint equations, which are difficultly solved simultaneously. This paper proposes an alternative approach. A set of global variables based on the D-H method is defined, and the Euler-Lagrange's equation is applied to derive the model without using any constraint equations. The developed model is a set of linear time-varying differential equations, which can describe the flexible motions with respect to the rigid body configuration. Furthermore, the natural frequency analysis and the convergence analysis are performed first, and then two types of paths are designed for the motions of the end-effector. The first path is a constant-speed circular motion in order to demonstrate the numerical simulations of the model at the steady state, and the second path is an inverted-U path, which is commonly used to operate a pick-to-place motion in industry. © 2016 Elsevier Ltd. Source


Wang Y.-R.,St. Johns University Taiwan | Horng S.-J.,National Taiwan University of Science and Technology
Expert Systems with Applications | Year: 2011

Real-time license plate recognition (LPR) is an interesting but complicated research topic. Some previous works use discrete wavelet transform (DWT) to extract license plate (LP), however, most of them are not capable of dealing with complex environments such as the low-contrast source images and the dynamic-range problems. In this paper, we propose an algorithm for license plate localization (LPL) based on DWT. The LP can be extracted from different quality of source images under complex environments by using two frequency subbands. We first use the HL subband to search the features of LP and then verify the features by checking whether in the LH subband there exists a horizontal line around the feature or not. The proposed method can extract both front and back LPs of various vehicles. The experimental results show that the proposed method can achieve good LPL results with both short run-time and high accurate detection rate. © 2010 Elsevier Ltd. All rights reserved. Source


Whiteley C.G.,National Taiwan University of Science and Technology
Neurochemistry International | Year: 2014

Even though the accumulation of arginine and the deposit of aggregated Aβ-peptides (senile plaques) in the brain of an Alzheimer patient are classic points of evidence in the neuropathology of the disease considerable dispute remains on their method of formation. One acceptable mechanism to initiate events is a 'seed' aggregation of free monomeric peptides into toxic soluble amyloid oligomers and subsequently into deposits of insoluble fibrils. Since all of these events take place in the brain astrocytes it suggests an interference between arginine-metabolising enzymes and the Aβ-peptides. Through kinetic, fluorimetric and thermodynamic analyses two such enzymes - neuronal nitric oxide synthase and peptidyl arginine deiminase - are, not only inhibited by structural fragments of Aβ1-42 but are catalytic towards fibrillogenesis. The interaction of the peptide fragments with each enzyme is endothermic, non-spontaneous and involves hydrophobic-hydrophobic associations with a single binding site. The trigger for this series of events focusses in particularly on Aβ17-21 with two phenylalanines [Phe19; Phe20], the three glycine zipper motifs [Aβ25-29; Aβ29-33; Aβ33-37] and the triple sequence [Aβ25-37] that includes two isoleucine residues [Ile31; Ile32]. FRET studies show the Aβ-peptide fragments bind to the enzymes <3.0 nm from a single surface tryptophan. Free Aβ monomers bind to an enzyme, formulate a nucleus, initiate their aggregation and subsequently become entrapped and couple to the existing aggregated monomers, leading to an elongated fibril. Silver and gold nanoparticles reverse fibrillogenesis! They are surrounded by the amyloid peptide molecules in vivo to effectively deplete their concentration. This does not allow any 'lag' time, nor prevent the formation of critical nuclei for the initial association phase and, inevitably, prevent fibril initiation and elongation. This review focusses on the function and action of arginine metabolising enzymes with respect to the formation of senile plaques and amyloid peptide aggregation to facilitate more of an understanding of neurodegeneration in Alzheimer disease. © 2014 Elsevier B.V. Source


Chen S.-J.,National Taiwan University of Science and Technology | Jhang C.,Sinotech Engineering Consultants
Journal of Constructional Steel Research | Year: 2011

This paper describes the study of the low-yield-point (LYP) steel plate shear walls under in-plane load. In the LYP steel plate shear wall system, LYP steel was selected for the steel plate wall while the boundary frame was constructed by the high strength structural steel. A series of experimental studies examined the inelastic shear buckling behavior of the LYP steel plate wall under monotonic in-plane load. The effects of width-to-thickness ratio on the shear buckling of LYP steel plates were examined. The stiffness, strength, deformation, and energy dissipation characteristics were investigated by performing cyclic loading tests on the multistorey LYP steel plate shear walls. Excellent deformation and energy dissipation capacity were obtained for all specimens tested. The LYP steel plate shear wall system is able to exceed 5% of storey drift angle under lateral force. © 2010 Elsevier Ltd. All rights reserved. Source


Yang C.-H.,National Taiwan University of Science and Technology
Journal of Computational and Theoretical Nanoscience | Year: 2013

Numerical results are studied for the control of chaos of Quantum-CNN oscillators with linear feedback, nonlinear sine function feedback, and nonlinear state cross cosine function feedback. The Routh-Hurwitz theorem is used to derive the conditions of stability of controlled Quantum-CNN systems. Copyright © 2013 American Scientific Publishers. Source


Yang C.-H.,National Taiwan University of Science and Technology
Journal of Computational and Theoretical Nanoscience | Year: 2013

A new strategy to achieve generalized chaos hybrid synchronization by GYC partial region stability theory is proposed. By using the GYC partial region stability theory the Lyapunov function is a simple linear homogeneous function of error states and the controllers are simpler and introduce less simulation error because they are in lower order than that of traditional controllers. In simulation examples, a LC (Liu-Chen) system is used. Copyright © 2013 American Scientific Publishers All rights reserved. Source


Tiwari J.N.,National Chiao Tung University | Tiwari R.N.,National Chiao Tung University | Lin K.-L.,National Taiwan University of Science and Technology
ACS Applied Materials and Interfaces | Year: 2010

Platinum (Pt) nanopetals were electrodeposited on highly ordered silicon nanocones (SiNCs) and explored as the electrocatalyst for methanol oxidation reaction (MOR) for direct methanol fuel cells applications. Highly ordered SiNCs array fabricated using the porous anodic aluminum oxide as the template had a high surface area. Well-dispersed Pt nanopetals possessing high electrocatalytic surface area was synthesized by pulse-electrodeposition on the SiNCs. Pt nanopetals loaded on highly ordered SiNC support exhibited very good catalytic activity for MOR and a high tolerance against CO poisoning, as compared to Pt nanoflowers/flat Si, Pt nanoparticles/flat Si, and many previously reported works. The abundance of a large surface area for facile transport of methanol, SiO 2 sites in the vicinity of the SiNCs, as well as less contact area between the Pt nanopetals catalyst and SiNCs are suggested to be the major factors enhancing the electrocatalytic performance of the Pt nanopetal/SiNC electrode. Moreover, we believe this new nanostructure (Pt nanopetals/SiNCs) will enable many new advances in nanotechnology. © 2010 American Chemical Society. Source


Tseng A.A.,National Taiwan University of Science and Technology
Applied Surface Science | Year: 2010

The patterning technique that uses an AFM (atomic force microscopy) tip as a scratch tool, also known as AFM scratching, has been a vital technique for nanofabrication because of its low cost and potential to reach a resolution into the sub-nanometer domain. The AFM scratching technique was first used to study the scratch characteristics of silicon, with an emphasis on establishing its scratchability or the nanoscale machinability. The effects of the scratch parameters, including the applied tip force and number of scratches, on the size of the scratched geometry were specifically evaluated. The primary property that measures the scratchability was identified and assessed. To illustrate its suitability and reliability, the value of the scratchability, based on the present Si scratching experiments, was compared with the values based on the data available in the literatures for different scratching conditions or for materials other than Si. Since AFM scratching is in some aspects similar to the nanoscale wear test, the scratchability property identified is also compared with two major wear resistance indicators, wear coefficient and hardness. All comparison results indicate that the scratchability property identified, the scratch ratio, is an appropriate manufacturability indicator for measuring the degree of the ease or difficulty of a material scratched by an AFM tip and more suitable than the wear coefficient and hardness to gauge the nanoscale AFM scratchability. © 2010 Elsevier B.V. All rights reserved. Source


Chu J.P.,National Taiwan University of Science and Technology | Wang Y.-C.,National Cheng Kung University
Acta Materialia | Year: 2010

By means of brief pauses in radiofrequency (RF) sputter deposition between individual layers, ultrathin copper oxide layers were formed through adsorption in the Cu/Cu multilayers. Their mechanical properties were compared with the Cu/Cu(O) multilayers whose oxide layers were deliberately deposited between copper layers. The mechanical hardness value of the Cu/Cu(O) multilayers approached that of nanostructured copper thin films. The Young's modulus of the multilayers was tunable, in accordance with the elasticity theories of composites. In addition, the Hall-Petch slope of the RF sputter-deposited Cu monolayers indicated that their theoretical strength approached the shear modulus of copper. © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. Source


Lee Y.-H.,Washington University in St. Louis | Bai M.-Y.,National Taiwan University of Science and Technology | Chen D.-R.,Washington University in St. Louis
Colloids and Surfaces B: Biointerfaces | Year: 2011

This study describes how a coaxial tri-capillary electrospray (ES) system can synthesize monodisperse PLGA-coated particles containing multiple drugs in one step. The coaxial arrangement of three separate capillaries in an ES nozzle enables production of composite particles with tri-layered structures without the complicated steps involved in emulsion processes. Various materials can be encapsulated in separate layers of individual composite particles without regard for the hydroscopic property of drugs. At the proper spray setting, nearly 100% drug encapsulation efficiency can be achieved. By varying the feed flowrate of spray solutions, the overall particle sizes, ranging from submicrometer to micrometer, and the thickness of the layers in produced particles can also be controlled. Size and tri-layered structure of the composite particles were characterized by SEM and laser scanning confocal microscopy (LSCM). We further explored the spray technique in the production of tri-layered composite particles having a controlled multidrug-release profile, and compared the release profiles of both core-shell structured particles (produced by coaxial dual-capillary ES) and tri-layered ones (produced by coaxial tri-capillary ES). The comparison showed that composite particles with the tri-layered structure can release multiple drugs in distinct kinetic phases. We further demonstrated that the release profile of tri-layered composite particles can be effectively controlled by varying the thickness and chemical composition of their individual layers. © 2010 Elsevier B.V. Source


Kuo R.J.,National Taiwan University of Science and Technology | Chang J.W.,ChipMOS Technologies
Journal of Intelligent Manufacturing | Year: 2015

This study intends to propose a feed-forward neural network for RFID positioning system. The proposed network integrates artificial immune network for optimization (Opt-aiNET) and artificial immune system (AIS) with clone selection to train the connecting weights of feed-forward neural network. It is able to learn the relationship between the received signal strength indication and picking cart position. Since the proposed learning algorithm owns both the merits of Opt-aiNET and AIS with clone selection, it is able to avoid falling into the local optimum and possesses the learning capability. The computational results for learning two continuous functions show that the proposed algorithm has better performance than other immune-based back-propagation neural network. In addition, the model evaluation results also indicate that the proposed algorithm really can predict the picking cart position more correctly than other methods. © 2013, Springer Science+Business Media New York. Source


Tsao Y.-C.,National Taiwan University of Science and Technology
International Journal of Systems Science | Year: 2015

This study models a joint location, inventory and preservation decision-making problem for non-instantaneous deteriorating items under delay in payments. An outside supplier provides a credit period to the wholesaler which has a distribution system with distribution centres (DCs). The non-instantaneous deteriorating means no deterioration occurs in the earlier stage, which is very useful for items such as fresh food and fruits. This paper also considers that the deteriorating rate will decrease and the reservation cost will increase as the preservation effort increases. Therefore, how much preservation effort should be made is a crucial decision. The objective of this paper is to determine the optimal locations and number of DCs, the optimal replenishment cycle time at DCs, and the optimal preservation effort simultaneously such that the total network profit is maximised. The problem is formulated as piecewise nonlinear functions and has three different cases. Algorithms based on piecewise nonlinear optimisation are provided to solve the joint location and inventory problem for all cases. Computational analysis illustrates the solution procedures and the impacts of the related parameters on decisions and profits. The results of this study can serve as references for business managers or administrators. © 2014 Taylor & Francis. Source


Tang H.H.,National Taiwan University of Science and Technology | Lee Y.Y.,Chang Gung University | Gero J.S.,George Mason University
Design Studies | Year: 2011

This study compares the design processes of designers in both digital and traditional sketching environments, where the digital environment emulates the traditional face-to-face, pen-and-paper environment. The design processes were empirically examined through protocol analysis using a coding scheme based on the function-behaviour-structure ontology. The distributions of the different types of segments, and their transitions in the two environments were quantitatively compared using Chi-Square tests and Paired-T tests. The results indicate that the design processes in the two environments were not statistically different in terms of their distributions and transitions. The higher-level cognitive activities were not affected by the change of medium. Some implications for design computing and design practice are discussed. © 2010 Elsevier Ltd. All rights reserved. Source


Hwang C.-L.,National Taiwan University of Science and Technology
IEEE Transactions on Fuzzy Systems | Year: 2011

Each subsystem of a nonlinear interconnected dynamic delayed system is approximated by a weighted combination of L transfer function delayed systems (TFDSs). The H 2-norm of the difference between the transfer function of a reference model and the closed-loop transfer function of the κth TFDS of subsystem i is then minimized to obtain a suitable frequency response without incurring oscillating and sluggish phenomena. Because of the existence of the disturbance at the output of the κth TFDS, which is not only large but also contains various frequency components, the H ∞-norm of the weighted sensitivity function between the output disturbance and its corresponding output of the κth TFDS is simultaneously minimized to reduce its effect. Furthermore, with proper selection of weighted sensitivity functions, certain specific modes of the output disturbance can be eliminated. Finally, two simulations are performed; one is the simulation of our designed TFDSs with different delays or nonminimum phases, and the other is the simulation of an internet-based intelligent space for the trajectory tracking of a car-like wheeled robot system. We demonstrate the effectiveness and efficiency of the proposed control. The main contributions of this paper are twofold. First, the control can simultaneously attain robust performance through the mixed H 2/H ∞ optimization with a Smith predictor and achieve the robust stability via L 2 N stable with finite gain. Second, fuzzy observer is not needed. © 2010 IEEE. Source


Lee Y.-H.,National Taiwan University of Science and Technology
Expert Systems with Applications | Year: 2011

The effectiveness of a neural network function depends on the network architecture and parameters. For discussing the relationship of parameters and performance, this study proposes a novel hand gesture recognition system (HGRS) combining the VICON and the back propagation neural network (BPNN). In this study, different numbers of hidden layer neurons and different numbers of layers were compared for effects on system performance. Too many or too few neurons reduced the recognition rate. Further, the hidden layer was needed for improving the system performance of the system. The training epoch size affects the general ability of the system. If the epoch size is too large, the system "over fit" the training set, and its general ability is impaired. However, an overly small epoch size would impair system recognition. The learning rate and system momentum affect the RMSE of the trained system. A higher learning rate and reduced momentum decrease RMSE. © 2011 Elsevier Ltd. All rights reserved. Source


Wang S.-C.,Lunghwa University of Science and Technology | Liu Y.-H.,National Taiwan University of Science and Technology
IEEE Transactions on Industrial Electronics | Year: 2011

Based on the redevelopment of control rule base, two modified PI-like fuzzy logic controllers with output scaling factor (SF) self-tuning mechanism are proposed and verified in this paper for application in the switched reluctance motor (SRM) drive system. The motivation of this paper is to simplify the program complexity of the controller by reducing the number of fuzzy sets of the membership functions (MFs) without losing the system performance and stability via the adjustable controller gain. For both types of controllers, the output SF of the controller can be tuned continuously by a gain updating factor, whose value is derived from the fuzzy logic reasoning, with the plant error and the error change ratio as the input variables. The rule bases are created based on the knowledge of the SRM's dynamic behavior and practical experience. Various aspects of the design considerations about the MF, rule base, and gain tuning strategy are described in detail. Experimental results, carried out on a four-phase 8/6-pole SRM based on the dSPACE DS1104 platform, are given to show the feasibility and effectiveness of the devised methods. A performance comparison of the proposed controllers with their conventional counterpart is also included. © 2010 IEEE. Source


Tien L.-C.,National Dong Hwa University | Chen W.-T.,National Dong Hwa University | Ho C.-H.,National Taiwan University of Science and Technology
Journal of the American Ceramic Society | Year: 2011

β-Ga2O3 nanobelts have been synthesized by a vapor transport process under different ambient oxygen. Their structural and optical properties were characterized by field-emission scanning electron microscopy, X-ray diffraction, photoluminescence (PL), and absorbance measurements. Structural characterization revealed that the as-synthesized samples consist of monoclinic β-Ga2O3 nanobelts with comparable surface area. Samples prepared under high oxygen ambient possessed large numbers of gallium-associated defects confirmed by PL and absorbance measurements. The photocatalytic activity of β-Ga2O3 nanobelts was evaluated by the degradation of organic dyes (rhodamine B and methyl blue) under ultraviolet light illumination. The results demonstrated that β-Ga2O3 nanobelts exhibited superior photocatalytic activity and stability as compared with commercial β-Ga2O 3 powder. The photocatalytic activity of β-Ga2O 3 nanobelts was greatly enhanced and attributed to the large numbers of acceptor states associated with gallium defects. The origin of enhanced photocatalytic activity of β-Ga2O3 nanobelts was discussed. © 2011 The American Ceramic Society. Source


Dang T.H.,National Cheng Kung University | Chen B.-H.,National Cheng Kung University | Lee D.-J.,National Taiwan University of Science and Technology
Bioresource Technology | Year: 2013

Biodiesel production from transesterification of vegetable oils in excess methanol was performed by using as-prepared catalyst from low-cost kaolin clay. This effective heterogeneous catalyst was successfully prepared from natural kaolin firstly by dehydroxylation at 800. °C for 10. h and, subsequently, by NaOH-activation hydrothermally at 90. °C for 24. h and calcined again at 500. °C for 6. h. The as-obtained catalytic material was characterized with instruments, including FT-IR, XRD, SEM, and porosimeter (BET/BJH analysis). The as-prepared catalyst was advantageous not only for its easy preparation, but also for its cost-efficiency and superior catalysis in transesterification of vegetable oils in excess methanol to produce fatty acid methyl esters (FAMEs). Conversion efficiencies of soybean and palm oils to biodiesel over the as-prepared catalysts reached 97.0. ±. 3.0% and 95.4. ±. 3.7%, respectively, under optimal conditions. Activation energies of transesterification reactions of soybean and palm oils in excess methanol using these catalysts are 14.09. kJ/mol and 48.87. kJ/mol, respectively. © 2012 Elsevier Ltd. Source


Cheng K.-C.,National Taiwan University of Science and Technology | Demirci A.,Pennsylvania State University | Catchmark J.M.,Pennsylvania State University
Applied Microbiology and Biotechnology | Year: 2011

Pullulan is a linear glucosic polysaccharide produced by the polymorphic fungus Aureobasidium pullulans, which has long been applied for various applications from food additives to environmental remediation agents. This review article presents an overview of pullulan's chemistry, biosynthesis, applications, state-ofthe- art advances in the enhancement of pullulan production through the investigations of enzyme regulations, molecular properties, cultivation parameters, and bioreactor design. The enzyme regulations are intended to illustrate the influences of metabolic pathway on pullulan production and its structural composition. Molecular properties, such as molecular weight distribution and pure pullulan content, of pullulan are crucial for pullulan applications and vary with different fermentation parameters. Studies on the effects of environmental parameters and new bioreactor design for enhancing pullulan production are getting attention. Finally, the potential applications of pullulan through chemical modification as a novel biologically active derivative are also discussed. © Springer-Verlag 2011. Source


Lee C.-L.,National Taitung University | Pan T.-M.,National Taiwan University of Science and Technology
Applied Microbiology and Biotechnology | Year: 2011

Alzheimer's disease is seen mainly in individuals over the age of 65, and the morbidity rate increases with age. Regarding the health function of Monascus-fermented red mold rice (RMR), besides hypolipidemic and hypotensive effects, other health functions of RMR such as anti-oxidation, cancer prevention, anti-fatigue, and anti-obesity have also been reported. Many published studies have shown the efficacy of RMR in the prevention of Alzheimer's disease. The current article discusses and provides evidence to support the beneficial potential of RMR in the prevention of Alzheimer's disease by discussing the pathogenic factors of Alzheimer's disease and the secondary metabolites of Monascus. © 2011 Springer-Verlag. Source


Wang C.-W.,National Taiwan University of Science and Technology | Hunter A.,University of Lincoln
International Journal of Computer Vision | Year: 2010

This paper presents a robust automated noninvasive video monitoring approach to recover the human pose in conditions with persistent heavy obscuration. The proposed methods are compared with Ramanan's stylized pose detection method and Wang's sequential pose model. The experimental results show that the proposed method performs significantly better than Ramanan's approach, is able to estimate the obscured body pose with various postures and obscuration levels in different environments, and is not sensitive to illumination changes. The system is evaluated in two domains: sleeping human subjects obscured by a bed cover, and pedestrians with a cluttered background scene, low feature contrast and baggy clothing. The body part detectors are trained in the sleep monitoring domain but are still able to estimate the pose in the pedestrian domain, demonstrating the robustness of the proposed technique. © 2010 Springer Science+Business Media, LLC. Source


Hung P.-H.,National University of Tainan | Hwang G.-J.,National Taiwan University of Science and Technology | Lee Y.-H.,National University of Tainan | Su I.-H.,National University of Tainan
Computers and Education | Year: 2012

Spatial ability has been recognized as one of the most important factors affecting the mathematical performance of students. Previous studies on spatial learning have mainly focused on developing strategies to shorten the problem-solving time of learners for very specific learning tasks. Such an approach usually has limited effects on improving the mathematical performance of students. In this study, a cognitive analysis approach is proposed for developing spatial learning tools by taking game characteristics into consideration. Moreover, the validation of the cognitive components of the spatial sense test for constructing two different kinds of intervention is verified.; the effects of the interventions are compared. To evaluate the performance of the proposed approach, an experiment was conducted on the mathematics course of an elementary school. The experimental results show that the spatial learning tool promotes not only the learning achievement, but also the spatial sense of the students. © 2012 Elsevier Ltd. All rights reserved. Source


Ho K.-L.,National Taiwan University | Lee D.-J.,National Taiwan University of Science and Technology
Bioresource Technology | Year: 2011

Harvesting biohydrogen from inhibiting wastewaters is of practical interest since the toxicity of compounds in a wastewater stream commonly prevents the bioenergy content being recovered. The isolated Clostridium sp. R1 is utilized to degrade cellobiose in sulfide or nitrite-containing medium for biohydrogen production. The strain can effectively degrade cellobiose free of severe inhibitory effects at up to 200mgl -1 sulfide or to 5mgl -1 nitrite, yielding hydrogen at >2.0mol H 2 mol -1 cellobiose. Principal metabolites of cellobiose fermentation are acetate and butyrate, with the concentration of the former increases with increasing sulfide and nitrite concentrations. The isolated strain can yield hydrogen from cellobiose in sulfide-laden wastewaters. However, the present of nitrite significantly limit the efficiency of the biohydrogen harvesting process. © 2011 Elsevier Ltd. Source


Huang D.-W.,National Taiwan University of Science and Technology | Shen S.-C.,National Taiwan Normal University
Journal of Functional Foods | Year: 2012

Tumour necrosis factor-α (TNF-α) plays a pivotal role in cellular insulin resistance and can induce insulin resistance in mouse FL83B hepatocytes. Caffeic acid and cinnamic acid were found to improve glucose uptake in TNF-α-treated insulin-resistant mouse FL83B hepatocytes. The mechanism of glucose metabolism by caffeic acid and cinnamic acid was further investigated. The result from Western blot analysis revealed that caffeic acid and cinnamic acid increased expression of glycogen synthase, whereas the expression of glycogen synthase kinase and phosphorylation of glycogen synthase at Ser641 in insulin-resistant mouse hepatocytes was decreased. Caffeic acid and cinnamic acid suppressed the expression of hepatic nuclear factor-4 in TNF-α-treated mouse FL83B hepatocytes. The activity of phosphoenolpyruvate carboxykinase was also inhibited. Thus, caffeic acid and cinnamic acid ameliorated glucose metabolism by promoting glycogenesis and inhibiting gluconeogenesis in TNF-α-treated insulin-resistant mouse hepatocytes. © 2012 Elsevier Ltd. Source


Tsai Y.-J.,Chung Shan Medical University | Hu C.-C.,Chung Shan Medical University | Chu C.-C.,Chung Shan Medical University | Imae T.,National Taiwan University of Science and Technology
Biomacromolecules | Year: 2011

This study successfully evaluated gene delivery and transfection toward rat C6 glioma cell lines mediated by intrinsic blue fluorescent poly(amido amine) (PAMAM) dendrimer. We used three antisense oligonucleotides, (AS-ODN) p75, NGF1, and NGF2 for knocking down specific protein expressions. The three oligonucleotides were electrostatically associated with the photoluminescent amino-terminated PAMAM dendrimer to yield fluorescent complexes at various nitrogen-to-phosphorus (N/P) ratios. Compared with pristine PAMAM dendrimer and hyperbranched polyethylenimine (PEI), the fluorescent PAMAM dendrimer revealed lower in vitro cytotoxicity toward C6 cells, allowing us to transfect the cells with the ASODN complexes under a higher N/P ratio. Due to the intrinsic fluorescence, cellular uptake behavior could be directly analyzed by fluorescence microscopy and flow cytometry, without additional fluorescence labeling. As expected, the result clearly suggested that the uptake efficiency increased as the N/P value increased. Furthermore, the quantified data obtained from flow cytometry indicated relatively higher uptake efficiency for the p75 complex, which is mainly due to different association patterns between the fluorescent dendrimer and AS-ODNs. At N/P = 20, atomic force microscopic analysis confirmed that the p75 complex formed well-condensed, spherical particles with dimensions less than 200 nm, but that NGF2 AS-ODN associated poorly with the dendrimer. Finally, Western blot analysis indicated that these complexes were capable of knocking down the specific protein expression to a certain level, being comparable to the hyperbranched PEI-mediated gene transfection. Our preliminary results clearly indicated that intrinsic fluorescent PAMAM dendrimers show promise as gene vehicles that can achieve delivery, transfection, and bioimaging at the same time. © 2011 American Chemical Society. Source


Wong B.-T.,National Taiwan University | Lee D.-J.,National Taiwan University of Science and Technology | Lee D.-J.,Fudan University
Bioresource Technology | Year: 2011

The inhibitory effects of 90-189mgl-1 of sulfide and 25-75mg-Nl-1 of nitrate on methanogenesis were investigated in a mixed methanogenic culture using butyrate as carbon source. In the initial phase of 90mgl-1S2- test, autotrophic denitrification of nitrate occurred with sulfide as the electron donor. Then the sulfate-reducing strains converted the produced sulfur back to sulfide via heterotrophic oxidation pathway. Methanogenesis was not markedly inhibited when 90mgl-1 of sulfide was dosed alone. When 25-75mg-Nl-1 of nitrate was presented, initiation of methanogenesis was seriously delayed. Nitrogen oxides (NOx), the intermediates for nitrate reduction via denitrification pathway, inhibited methanogenesis. The 90mgl-1 of sulfide favored heterotrophic dissimilatory nitrate reduction to ammonia (DNRA) pathway for nitrate reduction. Possible ways of maximizing methane production from an organic carbon-rich wastewater with high levels of sulfide and nitrate were discussed. © 2011 Elsevier Ltd. Source


Wang H.-Y.,National Cheng Kung University | Bernarda A.,National Cheng Kung University | Huang C.-Y.,National Tsing Hua University | Lee D.-J.,National Taiwan University of Science and Technology | Chang J.-S.,National Cheng Kung University
Bioresource Technology | Year: 2011

This review presents the development of micro-sized microbial fuel cells (including mL-scale and μL-scale setups), with summarization of their advantageous characteristics, fabrication methods, performances, potential applications and possible future directions. The performance of microbial fuel cells (MFCs) is affected by issues such as mass transport, reaction kinetics and ohmic resistance. These factors are manipulated in micro-sized MFCs using specially allocated electrodes constructed with specified materials having physically or chemically modified surfaces. Both two-chamber and air-breathing cathodes are promising configurations for mL-scale MFCs. However, most of the existing μL-scale MFCs generate significantly lower volumetric power density compared with their mL-counterparts because of the high internal resistance. Although μL-scale MFCs have not yet to provide sufficient power for operating conventional equipment, they show great potential in rapid screening of electrochemically microbes and electrode performance. Additional possible applications and future directions are also provided for the development of micro-sized MFCs. © 2010 Elsevier Ltd. Source


Liou H.M.,National Taiwan University of Science and Technology
Energy Policy | Year: 2011

The main aim of this paper is in discussing the outcome of the government's policies aimed at promoting the wind power industry. By analyzing the policies on renewable energy and the direct and indirect support mechanisms, the author reviews the achievements, limitations and strategies faced during their various stages. This research discovered that the series of measures adopted between 2000 and 2005 including installation plans, financial incentives, feed-in tariffs, export credit subsidies and R&D, helped to initiate the early steps of private investment, and allow domestic wind capacity to see stable growth. After 2005 with more clear goals set for wind energy installed capacity policies, R&D and industrial cooperation mechanisms, there was even greater breakthrough in limited market, enabling Taiwan's fledgling wind power industry to take its first steps onto the international production chain. In particular, the passing of the Renewable Energy Development Act in 2009 incited rapid growth in the domestic market as well as driving further development in the domestic wind energy industry. Overall, in current stage there is a need to get a handle on the gap still existing between international technology and market and that in Taiwan, in order to strategically develop a competitive advantage globally. © 2011 Elsevier Ltd. Source


Shen S.-C.,National Taiwan Normal University | Chang W.-C.,National Taiwan University of Science and Technology
Food Chemistry | Year: 2013

Vescalagin, an active component from Pink wax apple [Syzygium samarangense (Blume) Merrill and Perry cv. Pink] fruit, with glucose uptake enhancing ability in insulin-resistant FL83B mouse hepatocytes, as shown in our previous study, was further evaluated for its hypotriglyceridemic and hypoglycemic effects in high-fructose diet (HFD)-induced diabetic rats. Wistar rats were fed HFD for 16 weeks and orally administered with vescalagin from Pink wax apple daily during the last 4 weeks. The results of biochemical parameters showed that fasting blood glucose, C-peptide, fructosamine, triglyceride and free fatty acid contents decreased by 44.7%, 46.2%, 4.0%, 42.5%, and 10.8%, respectively, in the HFD-induced diabetic rats administered with vescalagin at 30 mg/kg body weight in comparison with those of control HFD-induced diabetic rats. However, high-density-lipoprotein-cholesterol content increased by 14.4% in the HFD rats treated with vescalagin. The present study reveals that vescalagin could have therapeutic value against diabetic progression via its anti-hypertriglyceridemic and anti-hyperglycemic effects. © 2012 Elsevier Ltd. All rights reserved. Source


Wang F.-K.,National Taiwan University of Science and Technology
IEEE Transactions on Semiconductor Manufacturing | Year: 2010

In this paper, we present a general procedure for evaluating the process yield with multiple characteristics in semiconductor manufacturing processes. The proposed process yield indices can be applied for multivariate normal distribution data or multivariate non-normal distribution data. These indices provide an exact measure of the overall process yield. Also, we show how to calculate the approximate lower confidence bound for the true process yield by using the one-to-one correspondence between the proposed process yield index and the overall process yield. Three examples are used to demonstrate the performance of the proposed approach. The results show that our procedure for evaluating the process yield with multiple characteristics is an effective approach. © 2010 IEEE. Source


Yu V.F.,National Taiwan University of Science and Technology | Lin S.-W.,Chang Gung University
Applied Soft Computing Journal | Year: 2014

The location routing problem with simultaneous pickup and delivery (LRPSPD) is a new variant of the location routing problem (LRP). The objective of LRPSPD is to minimize the total cost of a distribution system including vehicle traveling cost, depot opening cost, and vehicle fixed cost by locating the depots and determining the vehicle routes to simultaneously satisfy the pickup and the delivery demands of each customer. LRPSPD is NP-hard since its special case, LRP, is NP-hard. Thus, this study proposes a multi-start simulated annealing (MSA) algorithm for solving LRPSPD which incorporates multi-start hill climbing strategy into simulated annealing framework. The MSA algorithm is tested on 360 benchmark instances to verify its performance. Results indicate that the multi-start strategy can significantly enhance the performance of traditional single-start simulated annealing algorithm. Our MSA algorithm is very effective in solving LRPSPD compared to existing solution approaches. It obtained 206 best solutions out of the 360 benchmark instances, including 126 new best solutions. © 2014 Elsevier B.V. Source


Lu H.-P.,National Taiwan University of Science and Technology | Hsiao K.-L.,Shu-Te University
Information and Management | Year: 2010

Although social networking sites (SNSs) have attracted increased attention and members in recent years, there has been little research on it: particularly on how a users' extroversion or introversion can affect their intention to pay for these services and what other factors might influence them. We therefore proposed and tested a model that measured the users' value and satisfaction perspectives by examining the influence of these factors in an empirical survey of 288 SNS members. At the same time, the differences due to their psychological state were explored. The causal model was validated using PLS-Graph 3.0; six out of eight study hypotheses were supported. The results indicated that perceived value significantly influenced the intention to pay SNS subscription fees while satisfaction did not. Moreover, extroverts thought more highly of the social value of the SNS, while introverts placed more importance on its emotional and price value. The implications of these findings are discussed. Crown Copyright © 2010. Source


Kuo R.J.,National Taiwan University of Science and Technology | Lin L.M.,AU Optronics Corporation
Decision Support Systems | Year: 2010

This study proposes an evolutionary-based clustering algorithm based on a hybrid of genetic algorithm (GA) and particle swarm optimization algorithm (PSOA) for order clustering in order to reduce surface mount technology (SMT) setup time. Simulational results via Iris, Glass, Vowel and Wine benchmark data sets indicate that the proposed evolutionary-based clustering algorithm is more accurate than the GA-based and PSOA-based clustering algorithms. In addition, the model evaluation results which use order information provided by an international industrial personal computer (PC) manufacturer show that the proposed algorithm is also superior to GA-based and PSOA-based clustering algorithms. Through order clustering, scheduling orders that belong to the same cluster together can reduce production time as well as machine idle time. © 2010 Elsevier B.V. All rights reserved. Source


Chiang S.-S.,National Chung Hsing University | Pan T.-M.,National Taiwan University of Science and Technology
Applied Microbiology and Biotechnology | Year: 2013

Phytoestrogens are a class of bioactive compounds derived from plants and exert various estrogenic and antiestrogenic effects. Estrogen deficiency osteoporosis has become a serious problem in elderly women. The use of ovariectomized (OVX) rat or mice models to simulate the postmenopausal condition is well established. This review aimed to clarify the sources, biochemistry, absorption, metabolism, and mode of action of phytoestrogens on bone health in intervention studies. In vitro, phytoestrogens promote protein synthesis, osteoprotegerin/receptor activation of nuclear factor-kappa B ligand ratio, and mineralization by osteoblast-like cells (MC3T3-E1). In the OVX murine model, administration of phytoestrogens can inhibit differentiation and activation of osteoclasts, expression of tartrate-resistant acid phosphatase, and secretion of pyridinoline compound. Phytoestrogens also enhance bone formation and increase bone mineral density and levels of alkaline phosphatase, osteocalcin, osteopontin, and α1(I) collagen. Results of mechanistic studies have indicated that phytoestrogens suppress the rate of bone resorption and enhance the rate of bone formation. © 2013 Springer-Verlag Berlin Heidelberg. Source


This paper presents a method of designing hybrid analog/asymmetrical square-root (SR) FIR filters. In addition to the conventional frequency domain constraints, the proposed method considers time-domain constraints as well, including the inter-symbol interference (ISI) and the opening of the eye pattern at the receiver output. This paper also reviews a systematic way to find the discretetime equivalence of analog parts in a band-limited digital communication system. Thus, a phase equalizer can be easily realized to compensate for the nonlinear phase responses of the analog components. With the hybrid analog/SR FIR filter co-design, examples show that using the proposed method can result in a more robust ISI performance in the presence of the receiver clock jitter. © 2010 ETRI. Source


Chen K.-L.,National Taiwan University of Science and Technology
Environmental Economics and Policy Studies | Year: 2014

This study was conducted from ecological and economic points of view in the setting of a nature reserve of wetlands in Taiwan. The ecological data (including area, habitat and ornithological diversity, and ornithological rarity, population size, and representativeness) of 28 wetlands in Taiwan were collected, and “factor analysis” was used to regroup those attributes. The four common factors are rarity, area, representativeness, and diversity, with 36%, 36%, 15%, and 13% relative importance, respectively. A mix index is defined as the weighted average of these four factors. The ecological evaluation method and the results were introduced to the dichotomous choice with follow-up (DCF) contingent valuation questionnaire. Cameron’s expenditure function model and maximum likelihood estimation for DCF data provided by Alberini et al. were used to estimate willingness to pay values for the residents of Taiwan. The results indicate that some ecological factors are statistically significant, which shows the importance of combining ecological valuation and economic evaluation. The estimated median annual willingness to pay is NT$1069.52 with the exchange rate of US$1 ≒ NT$34.5. © 1999, Springer Japan. Source


Sun C.-Y.,Chang Gung University | Chang S.-C.,National Taiwan University of Science and Technology | Wu M.-S.,Chang Gung University
Kidney International | Year: 2012

The expression of the renoprotective antiaging gene Klotho is decreased in uremia. Recent studies suggest that Klotho may be a tumor suppressor, and its expression may be repressed by DNA hypermethylation in cancer cells. Here we investigated the effects and possible mechanisms by which Klotho expression is regulated during uremia in uninephrectomized B-6 mice given the uremic toxins indoxyl sulfate or p-cresyl sulfate. Cultured human renal tubular HK2 cells treated with these toxins were used as an in vitro model. Injections of indoxyl sulfate or p-cresyl sulfate increased their serum concentrations, kidney fibrosis, CpG hypermethylation of the Klotho gene, and decreased Klotho expression in renal tubules of these mice. The expression of DNA methyltransferases 1, 3a, and 3b isoforms in HK2 cells treated with indoxyl sulfate or p-cresyl sulfate was significantly increased. Specific inhibition of DNA methyltransferase isoform 1 by 5-aza-2′-deoxycytidine caused demethylation of the Klotho gene and increased Klotho expression in vitro. Thus, inhibition of Klotho gene expression by uremic toxins correlates with gene hypermethylation, suggesting that epigenetic modification of specific genes by uremic toxins may be an important pathological mechanism of disease. © 2012 International Society of Nephrology. Source


Ho C.-H.,National Taiwan University of Science and Technology
Applied Physics Letters | Year: 2010

Near band edge transitions of CuAlS2 chalcopyrite crystals have been characterized using temperature-dependent thermoreflectance (TR) spectroscopy in the temperature range between 30 and 340 K. A lot of interband transition features of EA n=2, EA n=3, EB n=2, EC, ED, EE, and EF were detected in the low-temperature TR spectrum of 3-6 eV at 30 K. Transition energies of the TR features of CuAlS 2 are analyzed. Transition origins of the features are evaluated. Optical-electric conversion behavior of CuAlS2 was evaluated by photoconductivity (PC) measurement at 300 K. The PC spectrum reveals that the maximum photoresponse occurs near the energy positions of EA n=2, EA n=3, and EB n=2 features. The features are the fundamental band edge excitons which dominate photoelectric conversion behavior of CuAlS2 ultraviolet solar-energy material. © 2010 American Institute of Physics. Source


Hsu S.-H.,National Taiwan University of Science and Technology
Applied Optics | Year: 2010

The coupling length of a directional coupler is strongly polarization dependent, especially for use in waveguide tap monitoring applications. To avoid severe polarization and maximize the wavelength flatness of optical waveguide taps, a 12 μm thick silicon-on-insulator (SOI) platform and Mach-Zehnder directional couplers implemented with the bending effect illustrated low coupling loss to a SMF-28 fiber, low polarization dependence, and insensitive wavelength on the tap port for monitoring applications. Our results demonstrated that the optical waveguide tap, which carries a portion of the light signal, showed a 0.077 coupling ratio and 0:2dB for the polarization-dependent loss. The wavelength variation for the coupling ratio was less than 4% across the entire C-band. A 0:26 dB per interface coupling loss was also achieved between the 12μm thick SOI waveguide and the SMF-28 fiber. © 2010 Optical Society of America. Source


Chu H.-C.,National University of Tainan | Hwang G.-J.,National University of Tainan | Tsai C.-C.,National Taiwan University of Science and Technology
Computers and Education | Year: 2010

Recent developments in computing and mobile technologies have enabled the mobile and ubiquitous learning approach, which situates students in an environment that combines real-world and digital-world learning resources. Although such an approach seems to be innovative and interesting, several problems have been revealed when applying it to practical learning activities. One major problem is owing to the lack of proper learning strategies or tools that can guide or assist the students to learn in such a complex learning scenario. Students might feel excited or interested when using the mobile devices to learn in the real world; however, their learning achievements could be disappointing. To cope with this problem, in this study, a knowledge engineering approach is proposed to develop Mindtools for such innovative learning scenarios. Experimental results from a natural science course of an elementary school show that this innovative approach not only enhances learning motivation, but also improves the learning achievements of the students. © 2009 Elsevier Ltd. All rights reserved. Source


Wei H.-L.,National Taiwan University of Science and Technology | Wang E.T.G.,National Central University
European Journal of Information Systems | Year: 2010

To understand the role of supply chain visibility in creating strategic value, this study uses the dynamic capabilities view to uncover the nature of supply chain visibility. The study identifies four important constructs of supply chain visibility that are helpful in driving supply chain reconfigurability and thus improving supply chain strategic performance. They are visibility for sensing, visibility for learning, visibility for coordinating, and visibility for integrating. The results show that visibility for sensing has direct impact on supply chain strategic performance. Empirical evidence also supports that visibility for learning, visibility for coordinating, and visibility for integrating are important for enhancing supply chain reconfigurability, thus creating strategic value in supply chains. Supply chain visibility therefore enables firms to reconfigure their supply chain resources for greater competitive advantage. Implications of the results regarding the nature and the role of supply chain visibility in enhancing supply chain strategic performance are provided. © 2010 Operational Research Society Ltd. All rights reserved. Source


Chen S.,National Taiwan University of Science and Technology
Computers and Education | Year: 2010

With an increasing number of studies evincing the effectiveness of simulation-based virtual laboratories (VLs), researchers have discussed replacing traditional laboratories. However, the approach of doing science endorsed by VLs has not been carefully examined. A survey of 233 online VLs revealed that hypothetico-deductive (HD) logic prevails in VL design. Most VLs convey an oversimplified view of scientific inquiry, which might handicap science education in terms of cultivating the ability to conduct authentic scientific inquiry and to solve everyday problems, or promoting students' scientific literacy. Ever since Duhem and Kuhn, philosophers of science have learned that the relationship between hypotheses and evidence is holistic rather than deductive; however the pedagogical value of this point has not received enough attention in science education. Many science educators and VL-designers still uncritically adhere to the HD method. This article comments on the HD method and how VLs can avoid embracing it. © 2010 Elsevier Ltd. All rights reserved. Source


Lee D.-J.,National Taiwan University of Science and Technology | Liao G.-Y.,National Taiwan University | Chang Y.-R.,National Taiwan University | Chang J.-S.,National Cheng Kung University
Bioresource Technology | Year: 2012

Filtration-based separation of Chlorella vulgaris, a species with excellent potential for CO 2 capture and lipid production, was investigated using a surface-modified hydrophilic polytetrafluoroethylene (PTFE) membrane. Coagulation using polyaluminum chloride (PACl) attained maximum turbidity removal at 200mgL -1 as Al 2O 3. The membrane filtration flux at 1bar increased as the PACl dose increased, regardless of overdosing in the coagulation stage. The filtered cake at the end of filtration tests peaked in solid content at 10mgL -1 as Al 2O 3, reaching 34% w/w, roughly two times that of the original suspension. Differential scanning calorimetry (DSC) tests demonstrate that the cake with minimum water-solid binding strength produced the driest filter cake. Coagulation using 10mgL -1 PACl as Al 2O 3, followed by PTFE membrane filtration at 1bar, is an effective process for harvesting C. vulgaris from algal froth. © 2011 Elsevier Ltd. Source


Wu C.-H.,National Taiwan University of Science and Technology
Transactions on Embedded Computing Systems | Year: 2010

The capacity of flash memory storage systems has been growing at a speed similar to many other storage systems. In order to properly manage the product cost, vendors face serious challenges in resource-limited embedded systems. In this article, a self-adjusting flash translation layer is proposed with low memory requirements. The objective of the design is to provide efficient address mapping and low garbage collection overhead, while controlling main memory usage of the flash translation layer. The capability of the design is evaluated over realistic workloads and benchmarks. System performance is also guaranteed under low memory requirements. © 2010 ACM. Source


Hung S.-T.A.,National Taiwan University of Science and Technology
Computers and Education | Year: 2016

Peer-to-peer feedback provision is considered crucial to student learning. However, although the studies on peer feedback abound in the literature, most target the face-to-face or written modality; few investigate the pedagogic potential of videos in enhancing students' engagement in the feedback provision process. The current research project thus bridged the research gap by investigating learner engagement through multimodal video feedback as compared to text-based feedback and by exploring the strategies learners employed as well as the challenges they encountered. A total of 60 English as a Foreign Language (EFL) learners participated in a semester-long video feedback project where they produced 3-min speech video clips and 2-min oral feedback video clips that contained multiple semiotic modes such as visual, verbal, and gestural. Data analyses performed on responses to a custom-designed questionnaire, interview transcripts, and learner reflections led to three major findings. First, learners in general valued the role that video technology played in feedback production and provision, delineating that feedback in the video mode cannot only promote more interaction but also foster more personalized learning and attentive engagement. Second, the study uncovered a number of cognitive and social strategies learners used to ensure fluency and accuracy of their oral feedback, to achieve cognitive goals by efficiently producing the feedback, to observe positively-reinforced behaviors from peers, and to cooperate with others to generate ideas for future improvement. Nevertheless, the project revealed some potential challenges associated with feedback development and technical problems. Finally, implications are proposed to facilitate feedback provision experience through video technology. © 2016 Elsevier Ltd. Source


Liou H.M.,National Taiwan University of Science and Technology
Renewable and Sustainable Energy Reviews | Year: 2011

In order to respond to calls for newly industrialized countries to take greater responsibility for reducing GHG emission levels in the 2012 post-Kyoto treaty era, the Taiwan government has in recent years actively promoted related strategic policies and laws. In June 2009 the government passed the 'Renewable Energy Development Act' along with amendments to the 'Energy Administration Act', while at the same time developing drafts of the 'GHG Reduction Act' and 'Energy Tax Act'. This set of related policies and legislation, create a basic foundation for Taiwan's international GHG reduction responsibilities, institutional capacity and systems potential. This process of promoting GHG reduction touches on a wide range of issues including objective energy structure, GHG emission structure, the set of policies and laws, as well as the horizontal, vertical and socio-cultural pressures of the legislative process. Therefore, the main purpose of this paper is, through a comparison of the strategies adopted in each of the four GHG reduction acts, to trace the legislative background behind related acts and analyze the main aims, control models adopted and interaction going on between these four GHG reduction acts. Moreover with these four acts touching on the need for changes to be made to the energy structure, industrial structure and energy efficiency, as well as consumer behavior and other issues, the author also discusses the domestic and international economic factors and socio-cultural pressures affecting the legislative process. Finally, a comparison of energy consumption, GHG emission and industrial output, will reveal the direction which current efforts to implement changes to Taiwan's industrial policy, CO2 reduction policy and legislation are moving. © 2010 Elsevier Ltd. All rights reserved. Source


Ho C.-H.,National Taiwan University of Science and Technology
Journal of the Electrochemical Society | Year: 2011

Band edge property of whole series Cu(AlxIn1-x)S 2 (0 ≤ x ≤ 1) chalcopyrite crystals has been characterized using polarized-thermoreflectance (PTR) measurements in the temperature range between 30 and 320 K. The polarization dependency of band-edge transitions in the Cu(AlxIn1-x)S2 (0 ≤ x ≤ 1) series clearly shows that E∥ exciton (E0) is only present in the E >11 1< polarization while E exciton (E0+δ ) appears merely in the E >11 1< polarized spectra. The energy separation between E and E is due to the crystal field splitting energy (δ) in the Cu(Al xIn1-x)S2 crystalline series. The E0 and E0 transitions show an anomalous temperature-energy shift with respect to the increase of temperatures from 30 to 320 K. The anomalous temperature-energy shift reveals a maximum turn-over temperature TMTO appeared at different temperatures for each of the Cu(AlxIn 1-x)S2 (0 ≤ x ≤ 1) compounds. Both the crystal-field splitting energy (δ) and maximum turn-over temperature (TMTO) varied linearly with the Al composition x indicated that the variations of bonding and electronic structures of the Cu(AlxIn1-x) S2 series are correlated with the change in lattice constants. The copper d electron's contribution should mainly dominate the band-edge nature in the Cu(AlxIn1-x)S2 (0 ≤ x ≤ 1) chalcopyrite series. © 2011 The Electrochemical Society. Source


Lee K.-W.,National Taiwan University of Science and Technology | Tsai M.-T.,National Cheng Kung University | Lanting M.C.L.,Southern Taiwan University of Science and Technology
Electronic Commerce Research and Applications | Year: 2011

Even though scholars have placed considerable focus on studying the attitudes and intentions towards using the virtual market (marketspace), there are still few studies that examine the potential effect of the physical market (marketplace) on the virtual market. The physical and virtual markets have some substitution effects; as users utilize the virtual market more frequently, they use the physical market less regularly. Under this premise, factors relating to the physical market may have a potential effect on the user's acceptance of the virtual market. The primary goal of this study was to explore the factors that affect the attitude and intention towards switching from the physical to the virtual market in the context of online banking. In total, 400 questionnaires were sent out and 250 effective questionnaires were returned, for an effective recovery rate of 62.5%. Factor analysis and regression analysis were used to examine the hypotheses. The results showed that perceived usefulness, perceived ease of use and offline trust have positive effects on attitude towards switching. Additionally, offline loyalty and switching costs had negative significant influence on attitude towards switching. Moreover, attitude towards switching had a positive effect on the behavior intention to switch. Finally, computer self-efficacy moderates the effect of attitudes and behavior intention towards switching to online banking. © 2010 Elsevier B.V. All rights reserved. Source


Liou H.M.,National Taiwan University of Science and Technology
Renewable and Sustainable Energy Reviews | Year: 2015

The current development of clean energy in Taiwan is in the embryonic stage. Even though in recent times Taiwan's development of renewable energy has emphasized wind power and photovoltaic power, current statistics show they supply only a small portion of total national power needs, and that wind power and solar power are still in development. In order to promote the growth of clean energy, it is necessary to compare the support mechanisms of developing clean energy in different countries. The success of implementing clear energy in Germany is often followed by other countries, including Taiwan. Thus, this paper explores the German experience of implementing a Feed-in Tariff (hereafter FIT) and compared it with the FIT system in Taiwan to illustrate the differences and similarities between these countries. The results could be used as a reference for the future modification of the FIT system in Taiwan. © 2015 Elsevier Ltd. All rights reserved. Source


Ho S.-H.,National Cheng Kung University | Chen C.-Y.,National Cheng Kung University | Lee D.-J.,National Taiwan University of Science and Technology | Chang J.-S.,National Cheng Kung University
Biotechnology Advances | Year: 2011

The problem of climate change arising mainly from CO2 emission is currently a critical environmental issue. Biofixation using microalgae has recently become an attractive approach to CO2 capture and recycling with additional benefits of downstream utilization and applications of the resulting microalgal biomass. This review summarizes the history and strategies of microalgal mitigation of CO2 emissions, photobioreactor systems used to cultivate microalgae for CO2 fixation, current microalgae harvesting methods, as well as applications of valuable by-products. It is of importance to select appropriate microalgal species to achieve an efficient and economically feasible CO2-emission mitigation process. The desired microalgae species should have a high growth rate, high CO2 fixation ability, low contamination risk, low operation cost, be easy to harvest and rich in valuable components in their biomass. © 2010 Elsevier Inc. Source


Chen Y.J.,National Taiwan University of Science and Technology | Sheu J.-B.,National Taiwan University
Journal of Cleaner Production | Year: 2013

This paper offers a prescriptive suggestion to preserve the extended producer responsibility goal in an eco-industrial park. A novel Hotelling model in reverse trading direction is developed to examine the technology-position decisions between specialized recycling processors. We find that the notion of eco-industrial parks may not always be compatible with extended producer responsibility, which motivates producers to improve their eco-design in clean production within the context of competition. Based on our analysis, competition helps certain types of parks become self-organized such that constituent firms spontaneously improve their eco-design. If eco-design is not improved in a park due to the existing competition and production conditions, an ordinary tax-subsidy should be sufficient to make the parks self-organized. Therefore, eco-industrial parks can be re-aligned to their environmental goals. Source


Li W.-C.,National Tsing Hua University | Chang T.-H.,National Taiwan University of Science and Technology | Lin C.,National Tsing Hua University | Chi C.-Y.,National Tsing Hua University
IEEE Transactions on Signal Processing | Year: 2013

This paper studies the coordinated beamforming design problem for the multiple-input single-output (MISO) interference channel, assuming only channel distribution information (CDI) known to the transmitters. Under a given requirement on the rate outage probability for receivers, we aim to maximize the system utility (e.g., the weighted sum rate, weighted geometric mean rate, and the weighed harmonic mean rate) subject to the rate outage constraints and individual power constraints. The outage constraints, however, lead to a complicated, nonconvex structure for the considered beamforming design problem and render the optimization problem difficult to handle. Although this nonconvex optimization problem can be solved in an exhaustive search manner, this brute-force approach is only feasible when the number of transmitter-receiver pairs is small. For a system with a large number of transmitter-receiver pairs, computationally efficient alternatives are necessary. Hence, the focus of this paper is the design of such efficient approximation methods. In particular, by employing semidefinite relaxation (SDR) and first-order approximation techniques, we propose an efficient successive convex approximation (SCA) algorithm that provides high-quality approximate beamforming solutions via solving a sequence of convex approximation problems. The solution thus obtained is further shown to be a stationary point for the SDR of the original outage constrained beamforming design problem. Furthermore, we propose a distributed SCA algorithm where each transmitter optimizes its own beamformer using local CDI and information obtained from limited message exchange with the other transmitters. Our simulation results demonstrate that the proposed SCA algorithm and its distributed counterpart indeed converge, and promising performance can be achieved for all the considered system utilities. © 2012 IEEE. Source


Huang C.-W.,National Tsing Hua University | Chang T.-H.,National Taiwan University of Science and Technology | Zhou X.,Australian National University | Hong Y.-W.P.,National Tsing Hua University
IEEE Transactions on Signal Processing | Year: 2013

This work examines the use of two-way training to efficiently discriminate the channel estimation performances at a legitimate receiver (LR) and an unauthorized receiver (UR) in a multiple-input multiple-output (MIMO) wireless system. This work improves upon the original discriminatory channel estimation (DCE) scheme proposed by Chang et al. where multiple stages of feedback and retraining were used. While most studies on physical layer secrecy are under the information-theoretic framework and focus directly on the data transmission phase, studies on DCE focus on the training phase and aim to provide a practical signal processing technique to discriminate between the channel estimation performances (and, thus, the effective received signal qualities) at LR and UR. A key feature of DCE designs is the insertion of artificial noise (AN) in the training signal to degrade the channel estimation performance at UR. To do so, AN must be placed in a carefully chosen subspace, based on the transmitter's knowledge of LR's channel, in order to minimize its effect on LR. In this paper, we adopt the idea of two-way training that allows both the transmitter and LR to send training signals to facilitate channel estimation at both ends. Both reciprocal and nonreciprocal channels are considered and a two-way DCE scheme is proposed for each scenario. For mathematical tractability, we assume that all terminals employ the linear minimum mean square error criterion for channel estimation. Based on the mean square error (MSE) of the channel estimates at all terminals, we formulate and solve an optimization problem where the optimal power allocation between the training signal and AN is found by minimizing the MSE of LR's channel estimate subject to a constraint on the MSE achievable at UR. Numerical results show that the proposed DCE schemes can effectively discriminate between the channel estimation and, hence, the data detection performances at LR and UR. © 2013 IEEE. Source


Cheng M.-Y.,National Taiwan University of Science and Technology | Hoang N.-D.,Duy Tan University
Tunnelling and Underground Space Technology | Year: 2014

In construction engineering, permeation grouting with microfine cement is a widely utilized approach for soil improvement. Hence, estimating groutability is a very important task that should be carried out in the planning phase of any grouting project. This research aims at establishing a novel method for groutability prediction with the utilization of microfine cement in sandy silt soil. The newly proposed approach integrates the Bayesian framework and the K-nearest neighbor (K-NN) density estimation technique. The Bayesian framework is used to achieve probabilistic groutability estimations. Meanwhile, the K-NN method is employed to approximate the conditional probability density functions. Moreover, to establish the new approach, 240 in-situ grouting cases have been recorded during the progress of Mass Rapid Transit and highway projects in Taiwan. Experimental results point out that the proposed method can deliver superior prediction accuracy. Hence, the new groutability estimation approach is a promising alternative to help construction engineers in grouting process assessment. © 2014 Elsevier Ltd. Source


Ng M.-C.,National Taiwan Normal University | Yang Y.-L.,National Taiwan University of Science and Technology | Lu K.-T.,National Taiwan Normal University
PLoS ONE | Year: 2013

Fragile X syndrome (FXS) is the most frequent inherited form of human mental retardation. It is characterized by cognitive impairment and physical and behavioral problems and is caused by the silencing of fmr1 transcription and the absence of the fmr1 protein (FMRP). Recently, animal models of FXS have greatly facilitated the investigation of the molecular and cellular mechanisms of this loss-of-function disorder. The present study was aimed to further characterize the role of FMRP in behavior and synaptic function by using fmr1 knockout zebrafish. In adult zebrafish, we found that fmr1 knockout produces the anxiolytic-like responses of increased exploratory behavior in light/dark and open-field tests and avoidance learning impairment. Furthermore, electrophysiological recordings from telencephalic slice preparations of knockout fish displayed markedly reduced long-term potentiation and enhanced long-term depression compared to wild-type fish; however, basal glutamatergic transmission and presynaptic function at the lateral (Dl) and medial (Dm) division of the dorsal telencephalon synapse remained normal. Taken together, our study not only evaluates the mechanism of FRMP but also suggests that zebrafish have valuable potential as a complementary vertebrate model in studying the molecular pathogenesis of human fragile X syndrome. © 2013 Ng et al. Source


Chien S.-C.,Aletheia University | Ou C.-Y.,National Taiwan University of Science and Technology
Applied Clay Science | Year: 2011

Previous studies have shown that the application of direct current (DC) during electro-osmosis with injection is effective in strengthening soft clay. However, the DC can be obtained from an alternating current supply by use of a current-switching arrangement called a rectifier and a filter. In this study, a novel technique of using the half wave rectification and full wave rectification (Harmonic waves) during electro-osmosis with injection was developed to expand the different types of power supply and to achieve an economic and practical goal. Owing to the reduction in the filter component for the half wave rectification and full wave rectification, the price of a power supply may be reduced. Results of this study indicate that an effective improvement was observed in the circular experimental cell by using a half wave rectification or full wave rectification on the soil's mechanical properties such as CPT. In particular, the improvement effect by using the full wave rectification is close to that using the rectification and filter in terms of region of improvement and average cone resistance. The confirmative experimental results also show that the improvement in a rectangular experimental cell by using the full wave rectification is close to that using the rectification and filter in terms of region of improvement and average cone resistance. Hence, the technique of the full wave rectification may be economically and practically applied in electro-osmotic chemical treatment for soil improvement. © 2011 Elsevier B.V. Source


Tsai H.-C.,National Taiwan University of Science and Technology
Expert Systems with Applications | Year: 2010

This study explores the effectiveness of results obtained by using proposed hybrid multilayer perceptron (HMLP) networks to predict strength in concrete cylinders, reinforced-concrete deep beams, and reinforced-concrete squat walls. Such HMLP networks were designed to incorporate one linear and three high-order layer connections. Of the latter, one, employed only in the first layer connection, was derived from drawings referenced in the literature and two were developed by the author for this study. To calculate appropriate network coefficients, this study designed a center-unified particle swarm optimization (CUPSO) approach, composed of a center particle and global and local variants, which is quite effective for optimization tasks. This study gathered 103, 62, and 62 datasets, respectively, from drawings in three cases reported in the literature. Results, which showed that certain high order HMLP models perform better than their traditional counterpart, evidence the efficacy of proposed HMLP families. Each family, comprising high-order models and a linear counterpart, achieved results that were superior to those attained using traditional MLP networks only. © 2009 Elsevier Ltd. All rights reserved. Source


Tseng C.-H.,National Taiwan University of Science and Technology
IEEE Transactions on Advanced Packaging | Year: 2010

In this paper, compact low-temperature co-fired ceramic (LTCC) rat-race couplers are developed using multilayered phase-delay and phase-advance T-equivalent sections. By taking advantage of the multilayered LTCC layout capability, compact 3-D phase-delay and phase-advance T-equivalent sections are designed, and then treated as fundamental elements to construct two types of LTCC rat-race couplers. One type of coupler consists of three phase-delay and a phase-advance sections, whereas the other type coupler is integrated by a phase-delay and three phase-advance sections. At the design frequency 2 GHz, both two types of couplers occupy 3.8×;3.8 mm2circuit sizes, namely areas of 0.025λ0 ×; 0.025λ0, where λ0 is the free-space wavelength. The measured results of the developed couplers agree the simulated results very well. It demonstrates that using multilayered phase-delay and phase-advance T-equivalent sections is an effective approach to miniaturize the circuit size of the rat-race coupler. © 2006 IEEE. Source


Wang H.-C.,National Taiwan University of Science and Technology
Behaviour and Information Technology | Year: 2014

For decades, the marketing guidelines of enterprise software providers have focused on those managers who are likely to be more innovative in adopting new information systems. The current study argues that this approach demands improvements for two reasons: (1) this tactic may be biased, since past studies have only examined the single trait of innovativeness and its impact on an individual adoption intention and (2) the organisational implementation intention might be more important than the individual adoption intention, but the former has been largely ignored in the existing literature. Based on the case of business intelligence (BI) systems and data from 62 senior managers, this study is a pioneer in that it empirically reveals that managers individual adoption intention is distinct from their organisational implementation intention. Further, while managers innovativeness may be a significant determinant of their individual adoption intention towards BI systems, the issue of whether managers actually implement BI systems in their organisations is dominated by their involvement characteristics. Fruitful suggestions are proposed for practitioners and scholars. © 2014 © 2014 Taylor & Francis. Source


Lin Y.-K.,National Taiwan University of Science and Technology
IEEE Transactions on Reliability | Year: 2010

To minimize transmission time, the quickest path problem arises to find a path which sends a given amount of data from the unique source to the unique sink. Two deterministic attributes are involved in this problem: the capacity, and the lead time. However, in many real-life networks such as computer systems, or telecommunication systems, the arc capacity should be multistate due to failure, maintenance, and other such conditions. Such a network is named a multistate flow network, and the minimum transmission time is thus not fixed. We modify the quickest path problem to a multistate case. The new problem is to evaluate the probability that d units of data can be transmitted from the unique source to the unique sink under both the time, and budget constraints. In particular, the data are transmitted through k separate minimal paths simultaneously. Such a probability is named system reliability. An efficient algorithm is proposed to generate all minimal system states fulfilling the demand, time, and budget constraints. The system reliability is subsequently computed in terms of such system states. The optimal k minimal paths with the highest system reliability can further be obtained. © 2010 IEEE. Source


Lin Y.-K.,National Taiwan University of Science and Technology
IEEE Transactions on Reliability | Year: 2010

Reducing the transmission time is an imperative issue for many real-life systems such as computers, telecommunication networks, and transportation systems. For a deterministic flow network, the well-known quickest path problem is to find a path with minimum time for sending a specified amount of data through a single minimal path. A stochastic-flow network (SFN) composed by multistate arcs is more suitable to describe some real systems. The minimum transmission time through a SFN is thus not fixed. Allowing the data to be sent through two disjoint minimal paths simultaneously will shorten the transmission time. Hence, this paper is concerned with evaluating the reliability defined as when a SFN can transmit a given amount of data through a specified pair of minimal paths simultaneously under both time and budget constraints. In terms of subsets-union methods, a solution procedure is first proposed to calculate the reliability. Furthermore, a spare routing for boosting the reliability is established in advance to indicate the first pair, and the spare pairs of minimal paths. The corresponding reliability can be subsequently computed. An easy criterion is finally proposed to derive an ideal spare routing with higher reliability. © 2010 IEEE. Source


Chiu S.-H.,National Taiwan University of Science and Technology
International Journal of Technology and Design Education | Year: 2010

Architectural design is a knowledge-intensive activity; however, students frequently lack sufficient knowledge when they practice design. Collaborative learning can supplement the students' insufficient expertise. Successful collaborative learning relies on knowledge sharing between students. This implies that the peers are a considerable design knowledge source for the students. However, students are involved in grade competition. Students may not be willing to share because knowledge is a critical resource for students' performance. The web technology has been used to facilitate knowledge exchange among students; nevertheless, the convenience of technology may tempt free riding behavior and impede the development of a knowledge sharing culture. The purpose of this exploratory study is to probe whether the peers and a web forum are the students' primary knowledge source by investigating students' knowledge sources during the design process. The results demonstrated that (1) studio-mates were a primary design knowledge source for the students, (2) the ill-defined nature of design problems may be the main contributing factor encouraging knowledge sharing behavior, (3) the shared web forum was not a primary knowledge source for the students and did not have a significant influence on the knowledge sharing culture, and (4) we can estimate the knowledge sharing culture in a design studio through investigating students' knowledge sources. Furthermore, several additional findings and implications are elaborated. © 2008 Springer Science+Business Media B.V. Source


Lin Y.-K.,National Taiwan University of Science and Technology
Journal of the Chinese Institute of Industrial Engineers | Year: 2010

The quickest path problem, a version of the shortest path problem, is to find a single quickest path that sends a given amount of data from the source to the sink with minimum transmission time. More specifically, the capacity of each arc in a network is assumed to be deterministic. However, in many real-life networks, such as computer systems, telecommunication systems, etc., the capacity of each arc is stochastic due to failure, maintenance, etc. Such a network is named a stochastic-flow network. Therefore, the minimum transmission time is not a fixed number. The transmission time can be reduced if the data are transmitted through several minimal paths simultaneously. Focusing on a stochastic flow network with multistate arcs, this article studies the stochastic quickest path problem. We evaluate the probability that d units of data can be sent through two minimal paths (MPs) simultaneously under time constraint T. Such a probability is named the system reliability. A simple algorithm is proposed to generate all (d, T)-MPs and the system reliability can then be computed in terms of (d, T)-MPs by applying inclusion-exclusion. © 2010 Chinese Institute of Industrial Engineers. Source


Liou H.M.,National Taiwan University of Science and Technology
Renewable and Sustainable Energy Reviews | Year: 2010

Under the current wave of international responses to the growing threat of climate change, Taiwan cannot afford to step back from its goal of advancing its renewable energy, strengthening its energy self sufficiency and energy security. This paper will first analyze the high level dependency structure of Taiwan's energy demands; then we will explore Taiwan current situation in terms of renewable energy development; furthermore from an overview of the course of changes and development in Taiwan's energy policy, highlight the commitment to and aims of Taiwan's Renewable Energy Development, made by the government at the Annual National Energy Conference. Fourth, we shall analyse technological R&D, incentives, taxes, market reforms and other related policy tools. Fifth, in light of public announcements and budgets set in recent years for Taiwan's renewable energy research plan, highlight main strategies being given impetus by the government. Sixth, the author will discuss the implications of recent significant legal reforms to the development of renewable energy in Taiwan and from the correlating aspects of industrial structures and energy consumption, take the first steps in emphasizing the urgent need for adjustments to be made to Taiwan's industrial structure. Finally, this paper will conclude by examining current policies, legislation and strategies which are in place to promote this area in Taiwan and discuss the potential competitiveness and future scenarios which the development of Renewable Energy could mean for Taiwan. © 2010 Elsevier Ltd. All rights reserved. Source


Lin Y.-K.,National Taiwan University of Science and Technology
Expert Systems with Applications | Year: 2010

This article mainly studies the reliability evaluation of an overall-terminal multistate flow network whose arcs are all bi-directed in terms of MPs (minimal paths). The telephone-communication system (in which each node denoting a telephone station can either call or receive a phone) and computer-communication system are typical ones of such networks. Given the system demand (d; di,j∈B) where di,j is the required demand between the node pair (i, j) ∈ B with a specified set of node pairs B and d the total demand requirement among all nodes, an algorithm is proposed first to find out all lower boundary points of (d; di,j∈B) (namely (d; di;j∈B)-MPs here) in terms of MPs. The system reliability can then be calculated in terms of the family of all (d; d i;j∈B)-MPs. One example is illustrated to show how all its (d; di;j∈B)-MPs are generated and how the reliability nay be calculated. © 2010 Elsevier Ltd. All rights reserved. Source


Wee H.-M.,Chung Yuan Christian University | Yang W.-H.,17F. 12 | Chou C.-W.,National Taiwan University of Science and Technology | Padilan M.V.,Chung Yuan Christian University
Renewable and Sustainable Energy Reviews | Year: 2012

Due to the depletion of traditional energy resources, such as crude oil, coal, and natural gas, many initiatives all over the world have addressed the efficient use or replacement of these resources. Several renewable energy sources have been introduced as alternatives to traditional sources to protect environmental resources and to improve the quality of life. This study assesses renewable energy sources from a supply chain perspective and presents an investigation of renewable energies focusing on four main components: renewable energy supply chain, renewable energy performance, and barriers and strategies to its development. The study provides managerial insights to governments, researchers, and stakeholders for the initiation of renewable energy use, and suggestions for overcoming the barriers to its development. © 2012 Elsevier Ltd. Source


Yang N.-C.,Yuan Ze University | Chen T.-H.,National Taiwan University of Science and Technology
Energy and Buildings | Year: 2012

This paper presents a detailed power flow solution approach to apply to the energy loss evaluation for branch circuits or feeders of a dwelling unit or building to examine the suitability of the usual loss factor approach. The time-to-time and season-to-season changes in active and reactive power consumptions for each appliance are considered. Considering that daily load curves are quite different for weekdays and holidays, and also different for different seasons, sixteen daily load curves are created to represent the daily consumption characteristics for each kind of appliance, eight for daily active and another eight for reactive power consumption. The detailed power flow solution approach has resulted in the explicit energy loss evaluations for branch circuits or feeders of a dwelling unit or building and their corresponding determination of the daily, weekly, monthly and annual system electrical parameters. The results mentioned above are then used as a benchmark to discuss the suitability of the loss factor approach for evaluating the energy loss of branch circuits or feeders of a dwelling unit or building. © 2011 Elsevier B.V. All rights reserved. Source


Lin C.-H.,Brown University | Lin C.-H.,National Taiwan University of Science and Technology | Kabrawala S.,Brown University | Fox E.P.,University of California at San Francisco | And 3 more authors.
PLoS Pathogens | Year: 2013

Candida albicans can stochastically switch between two phenotypes, white and opaque. Opaque cells are the sexually competent form of C. albicans and therefore undergo efficient polarized growth and mating in the presence of pheromone. In contrast, white cells cannot mate, but are induced - under a specialized set of conditions - to form biofilms in response to pheromone. In this work, we compare the genetic regulation of such "pheromone-stimulated" biofilms with that of "conventional" C. albicans biofilms. In particular, we examined a network of six transcriptional regulators (Bcr1, Brg1, Efg1, Tec1, Ndt80, and Rob1) that mediate conventional biofilm formation for their potential roles in pheromone-stimulated biofilm formation. We show that four of the six transcription factors (Bcr1, Brg1, Rob1, and Tec1) promote formation of both conventional and pheromone-stimulated biofilms, indicating they play general roles in cell cohesion and biofilm development. In addition, we identify the master transcriptional regulator of pheromone-stimulated biofilms as C. albicans Cph1, ortholog of Saccharomyces cerevisiae Ste12. Cph1 regulates mating in C. albicans opaque cells, and here we show that Cph1 is also essential for pheromone-stimulated biofilm formation in white cells. In contrast, Cph1 is dispensable for the formation of conventional biofilms. The regulation of pheromone- stimulated biofilm formation was further investigated by transcriptional profiling and genetic analyses. These studies identified 196 genes that are induced by pheromone signaling during biofilm formation. One of these genes, HGC1, is shown to be required for both conventional and pheromone-stimulated biofilm formation. Taken together, these observations compare and contrast the regulation of conventional and pheromone-stimulated biofilm formation in C. albicans, and demonstrate that Cph1 is required for the latter, but not the former. © 2013 Lin et al. Source


Chen J.-K.,National Chiao Tung University | Wang J.-H.,National Chiao Tung University | Fan S.-K.,National Chiao Tung University | Chang J.-Y.,National Taiwan University of Science and Technology
Journal of Physical Chemistry C | Year: 2012

Inspired by the adjustable adhesive ability of the gecko foot pad, alternately attaching to and detaching from where they climb, we used a fabrication process to generate well-defined pillar patterns of polymerized styrene and successively grafted n-isopropylacrylamide (NIPAAm) as thermally responsive terminating of the pillars. By varying the geometry of the patterns including aspect ratio and duty ratio (solid fraction), the respective roles of the geometry the pattern features on the static water contact angle (WCA), hysteresis, adhesive, and friction force at 25 and 50 °C have been systemically investigated. The fabrication strategy exploits surface textures of polystyrene (PS) and thermally responsive terminating of PNIPAAm as the artificial foot pad surface, which could generate alternately ca. 93.9 and 8.7 nN of adhesive force at 25 and 50 °C, respectively. The results indicate that the adjustable adhesive ability of the copolymer brushes could approach the climbing aptitude of a gecko much more closely. We develop a bioinspired artificial analog by using two common methods including atom-transfer radical polymerization (ATRP) and photolithography to adjust adhesion reversibly on a silicon surface. The advantage of the processing strategy described here is the potential to fabricate a device of an artificial foot pad to mimic the climbing aptitude of geckos vividly. © 2012 American Chemical Society. Source


Ho C.C.,National Taiwan University of Science and Technology
Expert Systems with Applications | Year: 2012

National Health Insurance system has been continuously revised due to rapid changes of society since its establishment, which caused gradual decrease of hospital income year by year, so all hospitals take the initiative to develop self-financed items to partially increase hospital incomes, thus it is crucial to develop assessment model of Health Management Center. The research adopts Fuzzy Analytic Hierarchy Process (FAHP) for customers to make weight assessment on evaluation indexes of Health Management Center. Five major perspectives for customers' selection of Health Management Center are summarized, orderly including (1) Health Management Department (2) Personnel Service Department (3) Health Examination Service Department (4) Marketing Department (5) Environment Department. In addition, in the aspect of importance, "regularly track recheck and provide timely medical service", "provide doctor's commentary and inspection report result and follow-up ambulatory care issues" and "reasonably charge" are consider to be three major indexes in all weights. Research results can be submitted to relevant health examination institutes and personnel of the hospital for reference to earn the opportunity of developing new customers and improve service quality. © 2011 Elsevier Ltd. All rights reserved. Source


Lin Y.-K.,National Taiwan University of Science and Technology
Expert Systems with Applications | Year: 2012

Two attributes, the capacity and the lead time, are involved in the quickest path problem which finds a path with the minimum transmission time. The capacity of each edge is assumed to be deterministic in this problem. However, in many real-life networks such as computer, telecommunication, logistics networks, etc.; each edge should be multistate due to failure, maintenance, etc. Such a network is named a multistate network. Hence, the minimum transmission time through a multistate network is not fixed. We evaluate the system reliability that a specified amount of data can be sent through a pair of minimal paths simultaneously within the time threshold. A solution procedure is first proposed to calculate it. In order to boost the system reliability, the network administrator decides the routing policy in advance to indicate the first and the second priority pairs of minimal paths. The second one will be responsible for the transmission duty if the first one fails. According to the routing policy, the system reliability can be subsequently computed. The case to transmit data through more than two minimal paths can be extended easily. © 2011 Elsevier Ltd. All rights reserved. Source


Chou J.-S.,National Taiwan University of Science and Technology | Tsai C.-F.,National Central University
Automation in Construction | Year: 2012

High performance concrete (HPC) is a complex composite material, and a model of its compressive strength must be highly nonlinear. Many studies have tried to develop accurate and effective predictive models for HPC compressive strength, including linear regression (LR), artificial neural networks (ANNs), and support vector regression (SVR). Nevertheless, in accordance with recent reports that a hierarchical structure outperforms a flat one, this study proposes a hierarchical classification and regression (HCR) approach for improving performance in predicting HPC compressive strength. Specifically, the first-level analyses of the HCR find exact classes for new unknown cases. The cases are then entered into the corresponding prediction model to obtain the final output. The analytical results for a laboratory dataset show that the HCR approach outperforms conventional flat prediction models (LR, ANNs, and SVR). Notably, the HCR with a 4-class support vector machine in the first level combined with a single ANNs obtains the lowest mean absolute percentage error. © 2012 Elsevier B.V. Source


Chen N.K.,National United University | Feng Z.Z.,National United University | Liaw S.K.,National Taiwan University of Science and Technology
Laser Physics Letters | Year: 2010

We demonstrate pulsewidth tunable Q-switched erbium fiber lasers using in-line high extinction ratio (>30 dB) abrupt-tapered fiber Mach-Zehnder block filter and tunable Fabry-Perot filter in laser cavity. The pulsewidth can be tuning over 78 ns-23 ms. © 2010 by Astro Ltd. Source


Lee J.-D.,Chang Gung University | Chiou Y.-H.,Chang Gung University | Guo J.-M.,National Taiwan University of Science and Technology
IEEE Transactions on Information Forensics and Security | Year: 2010

This work presents a novel reversible data-hiding scheme that embeds secret data into a transformed image and achieves lossless reconstruction of vector quantization (VQ) indices. The VQ compressed image is modified by the side-matched VQ scheme to yield a transformed image. Distribution of the transformed image is employed to achieve high embedding capacity and a low bit rate. Moreover, three configurations, under-hiding, normal-hiding, and over-hiding schemes, are utilized to improve the proposed scheme further for various applications. Experimental results demonstrate that the proposed scheme significantly enhances the compression ratio and embedding capacity. Experimental results also show that the proposed scheme achieves the best performance among approaches in literature in terms of the compression ratio and embedding capacity. © 2010 IEEE. Source


Hsu S.-H.,National Taiwan University of Science and Technology
Journal of the Optical Society of America B: Optical Physics | Year: 2010

The length of a directional coupler, including the straight and curved parts, is strongly polarization dependent, especially for use in waveguide tap monitoring applications. Three types of curved structure in the coupled regions are presented to demonstrate the different phase contributions in a directional coupler. A 12 μm thick silicon-on-insulator waveguide single-mode region was theoretically verified by using the beam propagation method, thereby significantly improving the polarization dependence and coupling loss with a conventional fiber. The Mach-Zehnder directional coupler made of a 12 μm thick silicon-on-insulator waveguide could minimize the severe polarization dependence on the optical tap port and achieve a flattened wavelength response by implementing the coupled phase effect from the directional coupler's curved structures. The results demonstrated that the optical waveguide tap port, carrying a portion of the light signal, showed a 0.024 coupling ratio and 0.3 dB for the polarization-dependent loss at a 1550 nm wavelength. The wavelength variation in the tap splitting ratio and polarization was less than 1% and 0.6 dB, respectively, across the entire C-band. A 0.26 dB per interface coupling loss was also achieved between the 12 μm thick silicon-on-insulator waveguide and SMF-28 fiber. © 2010 Optical Society of America. Source


Lin F.-J.,National Central University | Hwang J.-C.,National Taiwan University of Science and Technology | Chou P.-H.,National Dong Hwa University | Hung Y.-C.,National Central University
IEEE Transactions on Power Electronics | Year: 2010

A field-programmable gate array (FPGA)-based intelligent-complementary sliding-mode control (ICSMC) is proposed in this paper to control the mover of a permanent magnet linear synchronous motor (PMLSM) servo-drive system to track periodic-reference trajectories. First, the dynamics of the field-oriented control PMLSM servo drive with a lumped uncertainty, which contains parameter variations, external disturbances, and nonlinear-friction force, is derived. Then, to achieve the required high-control performance, the ICSMC is developed. In this approach, a radial-basis function-network (RBFN) estimator with accurate approximation capability is employed to estimate the lumped uncertainty directly. Moreover, the adaptive-learning algorithms for the online training of the RBFN are derived using the Lyapunov theorem to guarantee the closed-loop stability. Furthermore, the FPGA chip is adopted to implement the developed control and online learning algorithms for possible low-cost and high-performance industrial applications using PMLSM. Finally, some experimental results are illustrated to show the validity of the proposed control approach. © 2010 IEEE. 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


Tsai J.-L.,National Taiwan University of Science and Technology
Information Technology and Control | Year: 2010

In 2004, Yang et al. proposed an efficient user identification scheme with key distribution. The scheme provides user anonymity, so it is possible for the user to anonymously login the remote server. Unfortunately, Mangipudi and Katti found that Yang et al.'s scheme suffers from a Denial-of-Service (DoS) attack and then proposed an improvement of Yang et al.'s scheme. However, Hsu and Chuang demonstrated that Mangipudi-Katti's scheme is vulnerable to an identity disclosure attack, and further proposed a novel user identification scheme with key distribution preserving user anonymity for distributed computer networks. They claimed that their scheme can achieve the following advantages: (1) user anonymity, (2) key distribution, (3) mutual authentication, and (4) key confirm. In this study, the author shows that Hsu-Chuang's scheme is vulnerable to three impersonation attacks. Then, the improvement of Hsu-Chuang's scheme is proposed. Source


Guo J.-M.,National Taiwan University of Science and Technology
Digital Signal Processing: A Review Journal | Year: 2010

Block truncation coding is an efficient compression technique while offering good image quality. Nonetheless, the blocking effect inherent in BTC causes severe perceptual artifact in high compression ratio applications. In this study, the ordered dither block truncation coding (ODBTC) is proposed to solve this problem, where the dither array look up table (LUT) approach is proposed to significantly reduce the complexity of the BTC. Moreover, a novel progressive coding scheme is presented for efficiently displaying ODBTC images. The ODBTC utilizes the characteristic of the bit-interleaved bit map to determine the transmitting order and then progressively reconstructs the ODBTC image. In addition, the progressive ODBTC can provide higher compression ratio by toggling and entropy coding treatments. The experimental results demonstrate high-quality reconstructions while maintaining low transmitted bit rates. © 2009 Elsevier Inc. All rights reserved. Source


Kuo Y.-L.,National Taiwan University of Science and Technology
Journal of Computational and Theoretical Nanoscience | Year: 2012

The r-refinement of the finite element method locates the positions of nodes to increase accuracy based on a mesh with a given number of elements and a given set of nodal variables. In contrast to the h- and p-refinements, the r-refinement does not increase the number of degrees of freedom to increase the accuracy of approximated solutions. This paper presents the application of the enhanced r -refinement, which incorporates with the h- or p-refinements, to two-dimensional elastic problems based on the error minimization of some certain physical quantities. The results demonstrate the adaptive meshes with the minimum errors and provide the selection guidelines of the meshes. Copyright © 2012 American Scientific Publishers All rights reserved. Source


Tsao Y.-C.,National Taiwan University of Science and Technology
International Journal of Production Economics | Year: 2015

Numerous manufacturers use brand advertising or make related promotional efforts to differentiate their product from other products on the market and stimulate demand. In the presence of manufacturer promotional efforts, cooperative promotion is the practice of a retailer sharing the manufacturer's promotional cost to stimulate sales. The retailer is interested in knowing how the promotional cost-sharing policy affects the channel members' decisions and, consequently, the profits. In this study, we considered a decentralized supply chain in which a risk-neutral manufacturer sells a single product to a risk-neutral retailer under manufacturer promotional efforts and demand uncertainty. The manufacturer determines the optimal wholesale price and promotional efforts and the retailer determines the optimal order quantity and retail price, both of whom are seeking to maximize their own profits. We demonstrated that the promotional cost-sharing policy motivates the manufacturer to increase promotional efforts and the retailer to order more products. However, the retailer is not willing to share the manufacturer's promotional cost when the retail price is exogenous because their profit will decrease. On the contrary, the retailer is willing to share the manufacturer's promotional cost only when the retail price is endogenous. © 2015 Elsevier B.V. All rights reserved. Source


Lee C.-L.,National Taitung University | Pan T.-M.,National Taiwan University of Science and Technology
Applied Microbiology and Biotechnology | Year: 2012

Monascus species has been used as the traditional food fungus in Eastern Asia for several centuries. Monascus- fermented products are gradually developed as the popular functional food for the prevention of cardiovascular disease, but we know that culture condition affects the hypolipidemic effect of Monascus-fermented product. In the past, the cholesterol-lowering agent-monacolin K-is regarded as the most important hypolipidemic agent. Two natural yellow pigments-monascin and ankaflavin-are also proven as novel hypolipidemic agents in recent years. However, the hypolipidemic effect of Monascus-fermented product should contribute from monacolin K, monascin, ankaflavin, and other unknown functional ingredients. In addition to hypolipidemic effect, the safety concern of Monascus-fermented product is involved in the levels of mycotoxin-citrinin. The hypolipidemic effect and the production of these functional metabolites or mycotoxin are influenced by many factors such as the choice of culture substrates, carbon and nitrogen source, pH value, extra nutrients, and so on. Therefore, this review focused on the effect of various culture conditions and nutrients on the functional metabolites production, hypolipidemic effect as well as citrinin concentration, and further organized the fermentation technologies used by previous studies for the promotion of hypolipidemic effect and safety. © Springer-Verlag 2012. Source


Cheng K.-H.,National Chiao Tung University | Tsai C.-C.,National Taiwan University of Science and Technology
Computers and Education | Year: 2014

Previous studies on augmented reality (AR) book learning have not provided an in-depth examination of the learning process, especially the interaction involved in child-parent shared book reading. Choosing an AR picture book to introduce its artistic work, this study aimed to explore how children and parents read the book through a series of analyses of behavioral patterns and cognitive attainment. A total of 33 child-parent pairs voluntarily participated in this study. Based on the indicators of the child-parent reading behaviors generated through content analysis, four behavioral patterns of AR picture book reading were identified: parent as dominator, child as dominator, communicative child-parent pair, and low communicative child-parent pair. The relationships between the child-parent reading behaviors and the children's cognitive attainment were further identified. Specifically, the child-parent behaviors of "parent as dominator" and "low communicative child-parent pair" were likely associated with simple description of the appearance of the artistic work by the children (low-level cognitive attainment). Conversely, the "child as dominator" and "communicative child-parent pair" behaviors resulted in the children explaining the artistic work they had seen or using their imagination to describe the content of the book (high-level cognitive attainment). © 2013 Elsevier Ltd. All rights reserved. Source


Rad R.M.,University of Malaya | Wong K.,University of Malaya | Guo J.-M.,National Taiwan University of Science and Technology
IEEE Transactions on Image Processing | Year: 2014

Conventionally, data embedding techniques aim at maintaining high-output image quality so that the difference between the original and the embedded images is imperceptible to the naked eye. Recently, as a new trend, some researchers exploited reversible data embedding techniques to deliberately degrade image quality to a desirable level of distortion. In this paper, a unified data embedding-scrambling technique called UES is proposed to achieve two objectives simultaneously, namely, high payload and adaptive scalable quality degradation. First, a pixel intensity value prediction method called checkerboard-based prediction is proposed to accurately predict 75% of the pixels in the image based on the information obtained from 25% of the image. Then, the locations of the predicted pixels are vacated to embed information while degrading the image quality. Given a desirable quality (quantified in SSIM) for the output image, UES guides the embedding-scrambling algorithm to handle the exact number of pixels, i.e., the perceptual quality of the embedded-scrambled image can be controlled. In addition, the prediction errors are stored at a predetermined precision using the structure side information to perfectly reconstruct or approximate the original image. In particular, given a desirable SSIM value, the precision of the stored prediction errors can be adjusted to control the perceptual quality of the reconstructed image. Experimental results confirmed that UES is able to perfectly reconstruct or approximate the original image with SSIM value > 0.99 after completely degrading its perceptual quality while embedding at 7.001 bpp on average. © 2013 IEEE. Source


Zhang J.,National Taiwan Normal University | Sung Y.-T.,National Taiwan Normal University | Hou H.-T.,National Taiwan University of Science and Technology | Chang K.-E.,National Taiwan Normal University
Computers and Education | Year: 2014

Based on kinesthetic learning style theory and interviews regarding teachers' experiences applying traditional astronomy teaching methods, a mobile digital armillary sphere (MDAS) using augmented reality (AR) was developed for use during astronomical observation instruction. The MDAS enables visual processes and limb movements similar to those that would occur in actual outdoor experiences to be employed in the classroom, thereby overcoming existing instructional limitations. A quasi-experimental design method was adopted, and 200 fifth-grade students were selected as participants. The use of the MDAS in astronomical observation courses affected students' learning effectiveness and interest. The experimental results indicated that using the MDAS system during outdoor observation activities effectively enhanced both the students' learning of astronomical observation content and their performance of astronomical observation skills. In addition, use of the MDAS effectively increased students' interest in astronomical observations and learning, which had a substantial effect on retention. © 2014 Elsevier Ltd. All rights reserved. Source


Tao T.,Taipei Chengshih University of Science and Technology | Su S.-F.,National Taiwan University of Science and Technology
IEEE Transactions on Fuzzy Systems | Year: 2014

In this paper, a novel control scheme adopted from moment control is proposed. In the proposed approach, an adaptive fuzzy system is employed to learn the effective moment. It is easy to see that such an approach can avoid wild guessing for the effective moment, and as shown in our simulation, can have nice control performance. In traditional adaptive fuzzy control approaches, bounds of system functions are required to facilitate supervisory control so as to have the robust control property. It can be expected that when those bounds used in the supervisory controller are not proper, the output may not be able to follow the reference trajectory satisfactorily. With the proposed moment adaptive fuzzy control, the bound needed is only the supremum of the control variance between two consecutive steps. It is much easier to predict. In our study, in order to further relax this requirement, another adaptive system is employed to estimate the residue of the moment adaptive fuzzy control system. It is called residue compensation in this paper. It can be found that with residue compensation, the approach does not need a supervisory controller, but still can quickly track the reference in a satisfactory fashion. Various simulations are conducted to demonstrate the effectiveness of the proposed approaches. © 1993-2012 IEEE. Source


Muntohar A.S.,Muhammadiyah University of Yogyakarta | Liao H.-J.,National Taiwan University of Science and Technology
Natural Hazards | Year: 2010

Shallow slope failure due to heavy rainfall during rainstorm and typhoon is common in mountain areas. Among the models used for analyzing the slope stability, the rainwater infiltration model integrated with slope stability model can be an effective way to evaluate the stability of slopes during rainstorm. This paper will propose an integrated Green-Ampt infiltration model and infinite slope stability model for the analysis of shallow type slope failure. To verify the suitability of the proposed model, seven landslide cases occurred in Italy and Hong Kong are adopted in this paper. The results indicate that the proposed model can be used to distinguish failed and not-yet failed slopes. In addition, the proposed model can be used as the first approximation for estimating the occurrence time of a rainfall-induced shallow landslide and its depth of sliding. © 2010 Springer Science+Business Media B.V. Source


Hsiao C.-H.,Kainan University | Tang K.-Y.,National Taiwan University of Science and Technology
Library Hi Tech | Year: 2014

Purpose: The current study aims to investigate college students' behavioral intentions to adopt e-textbooks for their studies according to well-known theoretical intention-based models. Design/methodology/approach: This paper empirically assesses five theoretical models of technology acceptance, including the theory of planned behavior (TPB), the technology acceptance model (TAM), the decomposed TPB model (DTPB), the combined model of TAM and TPB (C-TAM-TPB), and the unified theory of acceptance and use of technology (UTAUT). The survey methodology and structural equation modeling (SEM) were employed to examine and compare these five models. Moreover, explanatory power, goodness-of-fit indices, and model parsimony were taken into consideration in the model comparisons. Findings: Both TPB and TAM provided less effective but adequate predictive behavioral power. However, TPB appeared to be more parsimonious than TAM and the other models. By focusing on specific beliefs of attitude, social and control influences, DTPB shares many of the same advantages as TPB and TAM, but is less parsimonious. Similarly, C-TAM-TPB, an augmented version of TAM that incorporates social influences and behavioral control, is superior to TPB and TAM in terms of its explanatory power of behavioral intention to use e-textbooks. Overall, however, the results indicated that UTAUT appeared to be the best model in terms of the metrics of parsimonious fit and explanatory power. Originality/value: Theoretical comparison of different models is important. This is believed to be the first study to present model comparisons by investigating undergraduates' intention to adopt e-textbooks as tools for their on-campus learning in Taiwan. © Emerald Group Publishing Limited. Source


Tsai H.-C.,National Taiwan University of Science and Technology
Journal of Sound and Vibration | Year: 2010

The exact dynamic analysis of plane frames should consider the effect of mass distribution in beam elements, which can be achieved by using the dynamic stiffness method. Solving for the natural frequencies and mode shapes from the dynamic stiffness matrix is a nonlinear eigenproblem. The Wittrick-Williams algorithm is a reliable tool to identify the natural frequencies. A deflated matrix method to determine the mode shapes is presented. The dynamic stiffness matrix may create some null modes in which the joints of beam elements have null deformation. Adding an interior node at the middle of beam elements can eliminate the null modes of flexural vibration, but does not eliminate the null modes of axial vibration. A force equilibrium approach to solve for the null modes of axial vibration is presented. Orthogonal conditions of vibration modes in the Bernoulli-Euler plane frames, which are required in solving the transient response, are theoretically derived. The decoupling process for the vibration modes of the same natural frequency is also presented. © 2010 Elsevier Ltd. All rights reserved. Source


Yu V.F.,National Taiwan University of Science and Technology | Dat L.Q.,National Economics University
Applied Soft Computing Journal | Year: 2014

Ranking fuzzy numbers is a very important decision-making procedure in decision analysis and applications. The last few decades have seen a large number of approaches investigated for ranking fuzzy numbers, yet some of these approaches are non-intuitive and inconsistent. In 1992, Liou and Wang proposed an approach to rank fuzzy number based a convex combination of the right and the left integral values through an index of optimism. Despite its merits, some shortcomings associated with Liou and Wang's approach include: (i) it cannot differentiate normal and non-normal fuzzy numbers, (ii) it cannot rank effectively the fuzzy numbers that have a compensation of areas, (iii) when the left or right integral values of the fuzzy numbers are zero, the index of optimism has no effect in either the left integral value or the right integral value of the fuzzy number, and (iv) it cannot rank consistently the fuzzy numbers and their images. This paper proposes a revised ranking approach to overcome the shortcomings of Liou and Wang's ranking approach. The proposed ranking approach presents the novel left, right, and total integral values of the fuzzy numbers. The median value ranking approach is further applied to differentiate fuzzy numbers that have the compensation of areas. Finally, several comparative examples and an application for market segment evaluation are given herein to demonstrate the usages and advantages of the proposed ranking method for fuzzy numbers. © 2013 Elsevier B.V. All rights reserved. Source


Chiang T.H.C.,National Central University | Yang S.J.H.,National Central University | Hwang G.-J.,National Taiwan University of Science and Technology
Computers and Education | Year: 2014

Inquiry learning has been developing for years and many countries have incorporated inquiry learning into the scope of K-12 education. Educators have indicated the importance of engaging students in knowledge-sharing activities during the inquiry learning process. In this study, a location-based augmented reality (AR) environment with a five-step guiding mechanism is developed to guide students to share knowledge in inquiry learning activities. To evaluate the effectiveness of the proposed approach in terms of promoting the knowledge sharing behaviors of students, an experiment has been conducted in an elementary school natural science course. The participants were 57 fourth-grade students from an elementary school in Northern Taiwan, divided into an experimental group of 28 students who learned with the AR-based approach and a control group of 29 students who learned with the conventional in-class mobile learning approach. The students' learning behaviors, including their movements in the real-world environment and interactions with peers, were recorded. Accordingly, the learning patterns and interactions of the two groups were analyzed via lag-sequential analysis and quantitative content analysis. It was found that, in comparison with the conventional inquiry-based mobile learning activity, the AR-based inquiry learning activity is able to engage the students in more interactions for knowledge construction. The findings of this study provide guidance for helping teachers develop effective strategies and learning designs for conducting inquiry-based learning activities. © 2014 Elsevier Ltd. All rights reserved. Source


Chen C.-Y.,National Taiwan University | Wo A.M.,National Taiwan University | Jong D.-S.,National Taiwan University of Science and Technology
Lab on a Chip - Miniaturisation for Chemistry and Biology | Year: 2012

We present a microfluidic device to generate either statically spatial or dynamically temporal logarithmic concentrations. The temporal logarithmic concentration generator was also integrated with planar patch-clamp chips for dose-response assays on ion channels. Proposed serial dilution principle controls the flow pattern at each branching point via designing the flow resistance of microchannels. Simple and linear ratios of the flow resistance results in desired logarithmic concentration at outlets, where the concentrations can be dynamically altered by different combination of valve actuations, were demonstrated. Single-cell pharmacology on ion channels was implemented by sequentially applying logarithmic drug concentrations to patched cells. Inhibitory activity of potassium channels of human embryonic kidney cells was examined by tetraethylammonium solutions. Resulted IC 50 and Hill slope reveal excellent agreement with assays from manually prepared drug concentrations showing the practicability and preciseness of the present approach. Applications include cellular analysis under various drugs and/or logarithmic concentrations at the single-cell level. © 2012 The Royal Society of Chemistry. Source


Wang F.-K.,National Taiwan University of Science and Technology
Quality and Reliability Engineering International | Year: 2015

Process yield plays an important role in many manufacturing industries for measuring process performance. However, gauge measurement errors have significant effect on process capability analysis. In this study, we present a method based on the yield index to evaluate the process yield of nonlinear profiles in the presence of gauge measurement errors. The results indicate that the presence of gauge measurement errors in the data leads to different behaviors of the yield index estimator according to the existence of the gauge variability. Our proposed test procedure can be easily used to determine whether or not manufacturing processes meet the quality requirements when gauge measurement errors are considered. A real example from a manufacturing process is used to demonstrate the applications of the proposed method. © 2015 John Wiley & Sons, Ltd. Source


Wang F.-K.,National Taiwan University of Science and Technology
Quality and Reliability Engineering International | Year: 2015

The exponentially weighted moving average (EWMA) model has been successfully used in acceptance sampling plans. The EWMA model provides the quality information of the current lot and the preceding lots. In addition, a multiple dependent state (MDS) sampling plan considers the quality information of the preceding lots. In this study, we present two new sampling plans for linear profiles. One is based on EWMA model with yield index using the single sampling plan, and the other is based on EWMA model with yield index using the MDS sampling plans. The plan parameters are determined by a nonlinear optimization approach. As the smoothing parameter value equals to one, the first proposed plan becomes the traditional single sampling plan. In addition, we compare the proposed plans with the traditional single sampling plan. The results indicate that the MDS sampling plan based on EWMA model with yield index with smaller value of smoothing parameter performs better than the traditional single sampling plan and the single sampling plan based on EWMA model with yield index in terms of the sample size required. One real example is used to illustrate the proposed plan. © 2015 John Wiley & Sons, Ltd. Source


Kuo R.J.,National Taiwan University of Science and Technology | Chao C.M.,National Taipei University of Technology | Chiu Y.T.,National Taipei University of Technology
Applied Soft Computing Journal | Year: 2011

In the area of association rule mining, most previous research had focused on improving computational efficiency. However, determination of the threshold values of support and confidence, which seriously affect the quality of association rule mining, is still under investigation. Thus, this study intends to propose a novel algorithm for association rule mining in order to improve computational efficiency as well as to automatically determine suitable threshold values. The particle swarm optimization algorithm first searches for the optimum fitness value of each particle and then finds corresponding support and confidence as minimal threshold values after the data are transformed into binary values. The proposed method is verified by applying the FoodMart2000 database of Microsoft SQL Server 2000 and compared with a genetic algorithm. The results indicate that the particle swarm optimization algorithm really can suggest suitable threshold values and obtain quality rules. In addition, a real-world stock market database is employed to mine association rules to measure investment behavior and stock category purchasing. The computational results are also very promising. © 2010 Elsevier B.V. All rights reserved. Source


Fan N.-C.,National Tsing Hua University | Cheng F.-Y.,National Cheng Kung University | Ho J.-A.A.,National Taiwan University of Science and Technology | Ho J.-A.A.,National Tsing Hua University | Yeh C.-S.,National Cheng Kung University
Angewandte Chemie - International Edition | Year: 2012

Light-controlled: Biodegradable nanoparticles encapsulating an anticancer drug (red dots in picture) have been synthesized that carry photocaged folate groups on the surface. Upon irradiation the photocaging group (green) is removed and the free folate group, a tumor-homing agent, binds to folate receptors on cell surfaces, thus leading to specific targeting and cellular uptake. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Hung I.-C.,National Sun Yat - sen University | Yang X.-J.,National Sun Yat - sen University | Fang W.-C.,National Sun Yat - sen University | Hwang G.-J.,National Taiwan University of Science and Technology | Chen N.-S.,National Sun Yat - sen University
Computers and Education | Year: 2014

Engaging students in reflection during real-world observation and inquiry activities has been recognized as an important issue for improving students' learning achievement and motivation. Many studies in the literature have adopted text-based reflection prompts as an important strategy to promote learning performance, this study argues that using videos as a reflection prompt would be more effective for improving learners' ubiquitous learning experiences and can provide a more sensible scenario that is better fitting the real-world contexts than the text-based prompts. In this study, a context-aware video-based prompt approach is proposed for improving students' reflection levels and satisfaction by providing timely and personalized guidance using mobile, wireless communication and sensing technologies. An experiment was conducted for evaluating the effectiveness of the proposed video-based prompt strategy with 70 participants in two groups. The results show that learners' reflection levels were significantly improved with the use of the proposed approach and that positive attitudes were observed toward the use of video-based prompts in the context-aware ubiquitous learning environment. © 2013 Elsevier Ltd. All rights reserved. Source


Wang F.-K.,National Taiwan University of Science and Technology
Quality and Reliability Engineering International | Year: 2016

When the quality of a process is represented by a relationship between one response variable and one or more independent variables called a multiple linear profile with in statistical control, the process capability analysis is widely used to measure the capability of the process to manufactured item within the required tolerance. In this paper, we propose the difference test statistic to compare two processes for multiple linear profiles with one-sided specifications. The number of profiles required for a designated selection power and confidence level is also provided. The performance of the proposed method is assessed using simulation study. The results provide useful information to practitioners. A real data from the logistic service shows that our method performs well in the application. Copyright © 2014 John Wiley & Sons, Ltd. Source


Kuo F.-R.,National Sun Yat - sen University | Chen N.-S.,National Sun Yat - sen University | Hwang G.-J.,National Taiwan University of Science and Technology
Computers and Education | Year: 2014

Along with the advancement of information and communication technology, researchers have pointed out the necessity and challenges of developing effective instructional strategies to enhance students' web-based problem-solving performance, which refers to the ability of investigating a series of related problems via searching for, abstracting and summarizing information on the web. In this study, a creative thinking strategy is proposed to cope with this problem. Moreover, an experiment was conducted on 80 freshmen from two classes of a university to evaluate the effectiveness of the proposed approach. The experimental results show that the proposed approach improved the students' web-based problem solving performance in comparison with the conventional approach in terms of "problem finding" and "idea finding." Moreover, it was found that the proposed approach could improve the "fact finding" performance of the students with intuitive-type cognitive style. Accordingly, some implications and suggestions are given for educators who attempt to conduct web-based problem-solving activity. © 2013 Elsevier Ltd. Source


Hwang G.-J.,National Taiwan University of Science and Technology | Kuo F.-R.,National Sun Yat - sen University | Chen N.-S.,National Sun Yat - sen University | Ho H.-J.,National University of Tainan
Computers and Education | Year: 2014

Although students could effectively search for web data with proper keywords and select web pages related to the studied core issue, however summarizing or organizing the retrieved information remains a difficult task for them. Concept mapping is known to be an effective knowledge construction tool for helping learners organize important concepts related to a core issue. To address the problem, an integrated concept mapping and web-based problem-solving environment, CM-Quest, has been developed; moreover, an experiment has been conducted to evaluate the effectiveness of the approach on students' learning performance, learning satisfaction and cognitive load in an elementary school social studies course. The results show that the concept map-integrated approach can significantly enhance the students' web-based problem-solving performance, although the students showed lower degrees of technology acceptance and learning satisfaction in comparison with the conventional web-based problem-solving approach. Moreover, it is found that the students in the concept mapping group revealed higher cognitive loads than those in the control group, which could be the factor contributing to the lower technology acceptance degree and learning satisfaction. As a consequence, it is concluded that the integrated concept mapping and web-based problem-solving approach is helpful to students in guiding them to learn in a more effective way. On the other hand, it remains an open issue to find a suitable way of integrating concept maps into the learning process without introducing too much extra cognitive load so as to promote students' acceptance degree of using technology for better learning. © 2013 Elsevier Ltd. All rights reserved. Source


Ching J.,National Taiwan University | Phoon K.-K.,National University of Singapore | Phoon K.-K.,National Taiwan University of Science and Technology
Canadian Geotechnical Journal | Year: 2012

This study explores the possibility of modeling liquidity index, undrained shear strength, remolded undrained shear strength, preconsolidation stress, and vertical effective stress of structured clays (sensitive or quick clays) as a multivariate normal distribution. The literature is replete with correlation equations between two soil parameters. Consistent synthesis of more than two soil parameters through construction of a multivariate probability distribution function is rare, despite obvious practical usefulness of such an approach. This study compiles a large database of structured clays to construct the multivariate probability distribution among the aforementioned five soil parameters. This multivariate distribution is then used to simulate the correlations between soil parameters of interest and to derive useful equations for Bayesian inference. This constructed multivariate distribution and equations are further validated by another independent database of structured clays as well as by empirical equations proposed in the literature. Source


Wang Y.-C.,National Taiwan University | Wang D.-Y.,National Taiwan University | Jiang Y.-T.,National Taiwan Normal University | Chen H.-A.,National Taiwan University | And 5 more authors.
Angewandte Chemie - International Edition | Year: 2013

Calligraphic counter electrodes: An important photovoltaic application using FeS2 nanocrystal (NC) pyrite ink to fabricate a counter electrode as an alternative to Pt in dye-sensitized solar cells is demonstrated. FeS2 NC ink exhibits excellent electrochemical catalytic activity and remarkable electrochemical stability. ITO=indium-doped tin oxide. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Chang T.-H.,National Taiwan University of Science and Technology | Nedic A.,University of Illinois at Urbana - Champaign | Scaglione A.,University of California at Davis
IEEE Transactions on Automatic Control | Year: 2014

Various distributed optimization methods have been developed for solving problems which have simple local constraint sets and whose objective function is the sum of local cost functions of distributed agents in a network. Motivated by emerging applications in smart grid and distributed sparse regression, this paper studies distributed optimization methods for solving general problems which have a coupled global cost function and have inequality constraints. We consider a network scenario where each agent has no global knowledge and can access only its local mapping and constraint functions. To solve this problem in a distributed manner, we propose a consensus-based distributed primal-dual perturbation (PDP) algorithm. In the algorithm, agents employ the average consensus technique to estimate the global cost and constraint functions via exchanging messages with neighbors, and meanwhile use a local primal-dual perturbed subgradient method to approach a global optimum. The proposed PDP method not only can handle smooth inequality constraints but also non-smooth constraints such as some sparsity promoting constraints arising in sparse optimization. We prove that the proposed PDP algorithm converges to an optimal primal-dual solution of the original problem, under standard problem and network assumptions. Numerical results illustrating the performance of the proposed algorithm for a distributed demand response control problem in smart grid are also presented. © 1963-2012 IEEE. Source


Tsai H.-C.,National Taiwan University of Science and Technology
Journal of Sound and Vibration | Year: 2012

The dynamic stiffness method is the exact method for the dynamic analysis of plane frames using the continuous-coordinate system to consider the effect of mass distribution in beam elements. The dynamic stiffness method may create some null modes where the joints of beam element have null deformation. Unlike the Bernoulli-Euler frames, adding an interior node at the middle of the beam elements cannot normalize all the null modes of flexural vibration in the Timoshenko frames. The floating interior-node scheme is proposed to eliminate the null modes of flexural vibration in the Timoshenko frames. Orthogonal properties of vibration modes in Timoshenko plane frames are theoretically derived, through which the equations of motion in beam elements can be transformed into the decoupled equations of motion in terms of mode amplitudes. © 2012 Elsevier Ltd. All rights reserved. Source


Lin Y.-K.,National Taiwan University of Science and Technology
International Journal of Production Economics | Year: 2010

For a single-commodity stochastic flow network, the system capacity is the maximum flow from the source to the sink. We construct a p-commodity stochastic flow network with unreliable nodes, in which branches and nodes all have several possible capacities and may fail, to model a supply chain. Different types of commodities, transmitted through the same network simultaneously, consume the capacities of branches and nodes differently. That is, the capacity weight depends on branches, nodes and types of commodity. We first define the system capacity as a vector and propose a performance index, the probability that the upper bound of the system capacity is a given pattern. Such a performance index can be easily computed in terms of upper boundary states meeting the demand exactly. An efficient algorithm based on minimal cuts is thus presented to generate all upper boundary states. The manager can apply this performance index to measure the transportation level of a supply chain. © 2009 Elsevier B.V. All rights reserved. Source


Hsia C.-H.,Chinese Culture University | Guo J.-M.,National Taiwan University of Science and Technology
Signal Processing | Year: 2014

Moving object detection is a fundamental task on intelligent video surveillance systems, because it provides a focus of attention for further investigation. Thus, video object segmentation, which extracts the shape information of moving object from a video sequence, is a key operation for surveillance system. In this study, the current state-of-the-art in moving objects segmentation for intelligent video surveillance has been surveyed. An efficient modified directional lifting-based 9/7 discrete wavelet transform (MDLDWT) structure is proposed to further reduce the computational cost and preserve the fine shape information in low resolution image. Although perfect moving object detection in a practical environment is a challenging task due to the vague object shape issues in the low resolution configuration, the experimental results document that the proposed low-complexity MDLDWT scheme can provide more precise detection rate for multiple moving objects, and the fine shape information can be effectively preserved for the real-time video surveillance applications in both indoor and outdoor environments. © 2013 Published by Elsevier B.V. All rights reserved. Source


Lin Y.-K.,National Taiwan University of Science and Technology
Expert Systems with Applications | Year: 2010

Network analysis is a usual approach to evaluate the performance of real-life systems such as transportation systems. We construct a multicommodity stochastic flow network with weighted capacity allocation to model the transportation systems. Each arc with cost attribute has several possible capacities. The capacity weight, the consumed quantity of arc capacity by per commodity, varies with the arcs and types of commodity. Nevertheless, the system capacity is not appropriate to be treated as the maximal sum of the commodity. We define the system capacity as a demand vector d if the system fulfills at most d. The main problem of this work is to measure the quality level of a transportation system. We propose a performance index, the probability that the upper bound of the system capacity equals a demand vector d subject to the budget constraint. A novel algorithm based on minimal cuts is presented to generate all maximal capacity vectors meeting exactly the demand d under the budget B. The performance index can then be evaluated in terms of such vectors. © 2009 Elsevier Ltd. All rights reserved. Source


Lin Y.-K.,National Taiwan University of Science and Technology
Information Sciences | Year: 2010

In this paper, a stochastic-flow network is presented to model a computer network in which each arc has various possible capacities and may fail. In order to shorten the transmission time, the transmission protocol allowing the data to be sent through multiple minimal paths simultaneously is utilized for the computer network. However, the minimum transmission time to send a given amount of data is not fixed due to the property of stochastic capacity. Accordingly, the first addressed issue is to evaluate the probability that the network is able to send the data within a time constraint by adopting the transmission protocol. Such a probability is named as transmission reliability that is regarded as a performance indicator to measure the QoS for a computer network. Without knowing all minimal paths in advance, an efficient solution procedure is proposed to calculate transmission reliability. The experimental results of 35 random networks show that the proposed algorithm can be executed efficiently. Moreover, in order to increase transmission reliability, the network administrator decides the routing policy to designate the first and the second priority p minimal paths. The second addressed issue is to evaluate transmission reliability associated with the routing policy. A sort criterion is subsequently presented to find an ideal routing policy. © 2010 Elsevier Inc. All rights reserved. Source


Kuo H.-F.,National Taiwan University of Science and Technology
IEEE Transactions on Nanotechnology | Year: 2014

According to the International Technology Roadmap for Semiconductors report, extreme ultraviolet (EUV) lithography is a key lithography tool for manufacturing devices at the 22-nm node and above. The current findings suggest that the lithographic image affects the critical dimensions (CDs) of wafers used in EUV lithography differently from those used in conventional lithography because of off-axis illumination and reflective optics design. The process windows of line/space (L/S) were explored, using a target CD of 22 nm and illuminating target contact hole (CH) features of a CD of 35 nm by using conventional, annular, dipole, and quasor source shapes. The diffraction amplitudes of the L/S and CH EUV masks and corresponding aerial images were calculated. The results indicate that the dipole is the favorable illumination source shape for printing the L/S features and the quasor is favorable for printing the CH features. In addition, the optimal dipole and quasor illumination settings are reported for the L/S and CH features, respectively. The exposure latitude was 4% and the depth of focus (DOF) was 100 nm to illuminate the L/S feature by using the dipole to print the target at a CD of 22. The exposure latitude was 24% and the DOF was 300 nm to illuminate the CH feature by using the quasor to print the target CD at 35 nm. © 2013 IEEE. Source


Hwang C.-L.,National Taiwan University of Science and Technology | Chiang C.-C.,Tatung University | Yeh Y.-W.,Tatung University
IEEE Transactions on Fuzzy Systems | Year: 2014

The trajectory tracking of uncertain underactuated nonlinear dynamic systems is tackled by an adaptive fuzzy hierarchical sliding-mode control (AFHSMC). First, one of the subsystems is assigned as the first layer sliding surface. Next, a second layer sliding surface from the first layer sliding surface and the sliding surface of another subsystem is constructed. In this paper, the nth layer is supposed to be the top layer (or hierarchical layer) for including the sliding surfaces of all subsystems. Because two nonlinear system functions and the time-varying external disturbance of each subsystem are supposed to be unknown, different online fuzzy models are employed to approximate these nonlinear system functions and the upper bounded functions of external disturbances. Moreover, the upper bound of uncertainties caused by these fuzzy modeling errors is estimated online. Based on these learning fuzzy models and the estimated upper bound of these modeling errors, an AFHSMC is developed. The stability analysis and tracking performance of the closed-loop system are verified by Lyapunov stability theory. Finally, two simulation examples including different amplitudes of external disturbance and comparison with hierarchical sliding-mode control confirm the effectiveness and robustness of the proposed control. © 1993-2012 IEEE. Source


Kuo Y.-C.,Kainan University | Chou J.-S.,National Taiwan University of Science and Technology
Expert Systems with Applications | Year: 2012

Condominium management (CM) businesses rely on continuous improvements to service quality (SQ) to increase consumer satisfaction (CS) and thereby improve operations. Lacking knowledge of SQ and CS results in poor efficiency. To develop cost-effective strategies for improvements, the relationship between SQ and CS must be investigated. This work proposes novel procedures to explore the relationship between identified SQ attributes and CS in the CM business. First, we conduct exploratory factor analysis to cluster intrinsically similar attributes into three constructs and identify significant attributes for subsequent assessment. Furthermore, resident satisfaction scores (RSSs) are computed to assess the relative importance rate (RIR) of investigated attributes by applying an adapted multivariate method to regress the RSSs on the performance of SQ attributes. To facilitate the decision-making process, the service-quality model evolved from the integration of an improved Kano's approach and importance-performance analysis (IPA) is utilized to develop a prioritized strategy for satisfaction improvements in the CM business. © 2011 Elsevier Ltd. All rights reserved. Source


Tu K.-J.,National Taiwan University of Science and Technology
Journal of Performance of Constructed Facilities | Year: 2016

Current sustainable building rating systems typically rate the energy performance of existing buildings by assessing how efficiently they consume energy, relative to similar buildings nationwide. In these rating systems, building type and external benchmark are the two notions typically employed. Alternatively, this study explores the notions of space type and internal benchmark and develops the benchmarking energy efficiency by space type for existing buildings (BEEST-EB) method to assess the energy efficiency of existing buildings. Specifically, core research concepts such as space type, standard operation settings, standard energy consumption, operational effectiveness index, and energy efficiency score are adopted in the BEEST-EB method. An existing building usually consists of different space types, each featuring similar operational characteristics and energy demands. It is therefore proposed that, for each space type, its standard operation settings should be defined and its standard energy consumption should be estimated with energy prediction models such as eQuest, accounting for the energy effects of additional factors such as existing climate and building infrastructure characteristics. The standard energy consumption of a building, revealing the performance of its building infrastructure while operating under standard settings, is regarded as its reasonable internal energy benchmark. The operational effectiveness index of a building is further assessed by calculating the ratio of its actual energy consumption to its standard energy consumption, and used to indicate how effectively the building is operated and managed. Finally, the energy efficiency of a building is evaluated by assessing both its standard energy consumption and operational effectiveness index jointly. Only buildings having high building infrastructure performance and high operational effectiveness simultaneously are rated as highly energy efficient buildings. The Department of Architecture of the national university NTUST in Taiwan is used as a case to demonstrate how the BEEST-EB method is employed to rate its energy efficiency and used as an effective energy management tool. © 2015 American Society of Civil Engineers. Source


Jang S.-L.,National Taiwan University of Science and Technology
IET Microwaves, Antennas and Propagation | Year: 2016

This study describes the design and operation principle of quadrature voltage-controlled oscillator (QVCO) with complementary current-reuse (CR) voltage-controlled oscillators (VCOs). One CR complementary metal-oxide semiconductor (CMOS) VCO consists of a pair of p-type metal-oxide semiconductor field-effect transistors (pMOSFETs) and n-type metal-oxide semiconductor field-effect transistors (nMOSFETs), and an inductor. The other CR VCO consists of a pair of pMOSFET and heterojunction bipolar transistors (HBTs), and one inductor. The two CR VCOs are used to construct differential VCOs, which are subsequently used to build QVCOs coupled via coupling networks. The Bipolar-CMOS (BiCMOS) VCO and QVCO have been implemented with the Taiwan Semiconductor Manufacturing Company, Limited (TSMC) 0.18 μm SiGe BiCMOS technology. The CMOS QVCOs have been implemented with the TSMC 0.18 μm CMOS process. The quadrature phase generation and oscillation frequency equations are derived based on the block diagram of QVCO circuit. © The Institution of Engineering and Technology. Source


Wang F.-K.,National Taiwan University of Science and Technology | Du T.,Chinese University of Hong Kong
Expert Systems with Applications | Year: 2014

In this study, we investigate the forecasting accuracy of motherboard shipments from Taiwan manufacturers. A generalized Bass diffusion model with external variables can provide better forecasting performance. We present a hybrid particle swarm optimization (HPSO) algorithm to improve the parameter estimates of the generalized Bass diffusion model. A support vector regression (SVR) model was recently used successfully to solve forecasting problems. We propose an SVR model with a differential evolution (DE) algorithm to improve forecasting accuracy. We compare our proposed model with the Bass diffusion and generalized Bass diffusion models. The SVR model with a DE algorithm outperforms the other models on both model fit and forecasting accuracy. © 2013 Published by Elsevier Ltd. Source


Cheng M.-Y.,National Taiwan University of Science and Technology | Hoang N.-D.,National University of Civil Engineering
Journal of Computing in Civil Engineering | Year: 2014

Bridges are essential infrastructure of the transportation network. Therefore, maintenance tasks are mandatory to prevent these structures from degradation over time. In practice, funding availability for maintenance projects is often confined and this necessitates prioritization of different bridges that are in need of remedial activities. The writers aim to construct an artificial intelligence (AI) approach, evolutionary fuzzy least-squares support-vector machine (LSSVM) inference model (EFLSIM), for prioritizing bridges based on risk scores (RSs). In EFLSIM, fuzzy logic (FL) is utilized to enhance the capability of approximate reasoning and to deal with subjective information, which is obtained from human judgment. The inference model employs LSSVM as a supervised learning technique to infer the fuzzy input-output mapping relationship. Differential evolution (DE) is integrated into the model to optimize its tuning parameters. Experimental results and comparison illustrates that EFLSIM can successfully absorb and simulate human knowledge in the bridge-assessment process. Additionally, the newly built model has outperformed other benchmark approaches in terms of both reliability and accuracy. A 10-fold cross-validation process has demonstrated that the EFLSIM has achieved more than 38% reduction in RMS error compared to other benchmark methods. Thus, the proposed AI approach is a promising tool to support decision-makers in bridge-maintenance planning. © 2014 American Society of Civil Engineers. Source


Chiang S.-S.,National Chung Hsing University | Pan T.-M.,National Taiwan University of Science and Technology
Applied Microbiology and Biotechnology | Year: 2012

It is well-known that probiotics have a number of beneficial health effects in humans and animals, including the reduction of symptoms in lactose intolerance and enhancement of the bioavailability of nutrients. Probiotics have showed to possess antimutagenic, anticarcinogenic and hypocholesterolemic properties. Further, they were also observed to have antagonistic actions against intestinal and food-borne pathogens, to decrease the prevalence of allergies in susceptible individuals and to have immunomodulatory effects. Typically, the bacteria colonise the intestinal tract first and then reinforce the host defence systems by inducing a generalised mucosal immune response, balanced T-helper cell response, self-limited inflammatory response and secretion of polymeric IgA. Scientific reports showed that the Taiwan native lactic acid bacterium from newborn infant faeces identified as Lactobacillus paracasei subsp. paracasei NTU 101 and its fermented products proved to be effective for the management of blood cholesterol and pressure, prevention of gastric mucosal lesion development, immunomodulation and alleviation of allergies, anti-osteoporosis and inhibition the fat tissue accumulation. This review article describes that the beneficial effects of this Lactobacillus strains and derivative products may be suitable for human and animals. © 2011 Springer-Verlag. Source


Sun C.-L.,National Taiwan University | Hsiao T.-H.,National Taiwan University of Science and Technology
Microfluidics and Nanofluidics | Year: 2013

In this study, we discuss the employment of microscale schlieren technique to facilitate measurement of inhomogeneities in a micromixer. By mixing dilute aqueous ethanol and water in a T-microchannel, calibration procedures are carried out to obtain the relation between the concentration gradients and grayscale readouts under various incident illuminations, concentrations of aqueous ethanol solution, and knife-edge cutoffs. We find that to broaden measuring range with minimal error, the luminous exitance should be tuned to have a reference background with an average grayscale readout of 121, and dilute aqueous ethanol solution with a mass fraction of 0.05 should be used along a 50 % cutoff. For concentration gradients greater than 6.8 × 10-3 or below -2.5 × 10-2 μm-1, the calibration curves show great linearity. Correspondingly, the discernable limit of our microscale schlieren system is 2.3 × 10-5 μm-1 for a positive refractive index gradient and -8.6 × 10-5 μm -1 for a negative refractive index gradient. Once the relation between concentration gradients and grayscale readouts is known, the concentration distribution in a microfluidic can be reconstructed by integrating its microscale schlieren image with appropriate boundary conditions. The results prove that the microscale schlieren technique is able to provide spatially resolved, noninvasive, full-field measurements. Since the microscale schlieren technique is directly linked to the measurement of a refractive index gradient, the present method can be easily extended to other scalar quantifications that are related to the variation of refractive index. © 2013 Springer-Verlag Berlin Heidelberg. Source


Yang C.-H.,National Taiwan University of Science and Technology
Journal of Computational and Theoretical Nanoscience | Year: 2011

A novel strategy to achieve chaos generalized synchronization by GYC partial region stability is proposed. By using the GYC partial region stability theory the Lyapunov function is a simple linear homogeneous function of states and the controllers are simpler and have less simulation error because they are in lower order than that of traditional controllers. Copyright © 2011 American Scientific Publishers. Source


Tsai C.-C.,National Taiwan University of Science and Technology
Educational Technology and Society | Year: 2012

Online peer assessment has been advocated by numerous contemporary educators. This study interviewed forty students who had experienced an online peer assessment activity for learning. Each of these students was asked to complete a research proposal in an educational method course for peer assessment. Using the online peer assessment system, the students, who performed the roles of both authors and reviewers, submitted their proposals, reviewed their peers' work and obtained peers' comments. Based on the interview data, sixty percent of the students could gradually develop views of "epistemic relativism" and "social relativism" through the online peer assessment activity. "Epistemic relativism" refers to recognition of the diversity of knowledge perspectives involved in a research issue, while "social relativism" indicates an understanding of the multiplicity of peer perspectives. These two views, which are perceived as positive impacts of online peer assessment, have rarely been documented in the relevant literature. This study further found that students' epistemological beliefs were related to their views of "epistemic relativism," while their Internet self-efficacy was associated with their views of "social relativism." More sophisticated epistemological beliefs and higher Internet self-efficacy can likely facilitate the development of views regarding "epistemic relativism" and "social relativism". © International Forum of Educational Technology & Society (IFETS). Source


Tseng C.-W.,National Taiwan Ocean University | Chang H.-Y.,National Taiwan Ocean University | Chang J.-Y.,National Taiwan University of Science and Technology | Huang C.-C.,National Taiwan Ocean University
Nanoscale | Year: 2012

In this study, bimetallic platinum/gold nanoparticles (Pt/Au NPs) were found to exhibit peroxidase-like activity, and the deposition of mercury was found to switch the enzymatic activity to a catalase-like activity. Based on this phenomenon, we developed a new method for detecting mercury ions through their deposition on bimetallic Pt/Au NPs to switch the catalytic activity of Pt/Au NPs. Pt/Au NPs could be easily prepared through reduction of Au 3+ and Pt4+ by sodium citrate in a one-pot synthesis. The peroxidase catalytic activity of the Pt/Au NPs was controlled by varying the ratios of Pt to Au. The Pt0.1/Au NPs (prepared with a [Au 3+]/[Pt4+] molar ratio of 9.0/1.0) showed excellent oxidation catalysis for H2O2-mediated oxidation of Amplex® Red (AR) to resorufin. The oxidized product of AR, resorufin, fluoresces more strongly (excitation/emission wavelength maxima ca. 570/585 nm) than AR alone. The peroxidase catalytic activity of Pt0.1/Au NPs was switched to catalase-like activity in the presence of mercury ions in a 5.0 mM tris(hydroxymethyl)aminomethane (Tris)-borate solution (pH 7.0) through the deposition of Hg on the particle surfaces owing to the strong Hg-Au metallic bond. The catalytic activity of Hg-Pt0.1/Au NPs is superior (by at least 5-fold) to that of natural catalase (from bovine liver). Under optimal solution conditions [5.0 mM Tris-borate (pH 7.0), H2O2 (50 mM), and AR (10 μM)] and in the presence of the masking agents polyacrylic acid and tellurium nanowires, the Pt0.1/Au NPs allowed the selective detection of inorganic mercury (Hg2+) and methylmercury ions (MeHg+) at concentrations as low as several nanomolar. This simple, fast, and cost-effective system enabled selective determination of the spiked concentrations of Hg2+ and MeHg+ in tap, pond, and stream waters. This journal is © 2012 The Royal Society of Chemistry. Source


Lin Y.-K.,National Taiwan University of Science and Technology
Computers and Mathematics with Applications | Year: 2011

This paper extends the quickest path problem to a stochastic flow network in which the capacity of each arc is variable. We mainly evaluate the system reliability that d units of data can be sent from the source to the sink under both time threshold T and budget B. In particular, the data are transmitted through multiple disjoint minimal paths simultaneously in order to reduce the transmission time. A simple algorithm is proposed to generate all lower boundary points for (d,T,B), and the system reliability can then be computed in terms of such points by utilizing a union of subsets. Computational complexity in both worst case and average cases show that the proposed algorithm can be executed efficiently. © 2011 Elsevier Ltd. All rights reserved. Source


Cheng M.-Y.,National Taiwan University of Science and Technology | Hoang N.-D.,National University of Civil Engineering
Journal of Computing in Civil Engineering | Year: 2014

In the construction industry, estimating groutability is a crucial task in the planning phase of a grouting project. Hence, establishing an effective groutability prediction model that is simple to implement and can deliver quick responses with high accuracy is a practical need of construction engineers. In this research, a novel instance-based learning approach - Evolutionary Fuzzy k-Nearest Neighbor Inference Model (EFKNIM) - is proposed to forecast the result of grouting activities that employ microfine cement grouts. In the proposed model, the fuzzy k-nearest neighbor algorithm is used to classify grouting activities into two classes: success and failure. Meanwhile, the differential evolution optimization approach is deployed to select the most appropriate tuning parameters of the fuzzy k-nearest neighbor algorithm, namely the neighboring size (k) and the fuzzy strength (m). This integrated framework allows the EFKNIM to operate autonomously without human prior knowledge or tedious processes for parameter setting. An experiment using 240 in situ data samples demonstrates that the newly established groutability prediction model can outperform other benchmark approaches including the k-nearest neighbor, fuzzy k-nearest neighbor, logistic regression and artificial neural network algorithms. © 2014 American Society of Civil Engineers. Source


Mizutani E.,National Taiwan University of Science and Technology
International Journal of Advanced Manufacturing Technology | Year: 2014

The paper by Veeramani and Wang (Int J Adv Manuf Technol 28:541-550, 2006) published in this journal offers a general bid construction scheme for minimizing the job flow time in auction-based manufacturing control and claims the optimality of the procedure. The purpose of this note is to provide a small example, in which their proposed new method fails to produce an optimal solution. We also address efficient correct algorithms so as to protect the readers from mistakenly believing that their new procedure is a better way of computing solutions. © 2013 Springer-Verlag London. Source


Wang F.-K.,National Taiwan University of Science and Technology
Quality and Reliability Engineering International | Year: 2015

A multiple stream process consists of several identical process streams. We present the process yield index SpkM for multiple stream processes with individual observations. An approximate distribution of the estimator of SpkM is derived. A simulation study is conducted to evaluate the performance of the confidence interval using the proposed method and the existing method. The simulation results show that the proposed method outperforms the existing method regarding interval length. We extend this process yield index for the case of subsamples. An approximate distribution for the estimator of Spk,sM is also derived. Two real examples are used to demonstrate the performance of the proposed approach. © 2015 John Wiley & Sons, Ltd. Source


Wang F.-K.,National Taiwan University of Science and Technology
Quality and Reliability Engineering International | Year: 2015

Acceptance sampling plans include a sampling scheme and a set of rules for determining whether an inspection lot from a supplier should be accepted or rejected. In some circumstances, the supplier is allowed to resubmit lots for further inspection when the original inspection result is unacceptable. In this study, two variables sampling plans based on the process-yield index for a process with linear profiles are proposed to deal with lot sentencing. The single sampling plan is a special case of the resubmitted lots sampling plan. The plan parameters are determined using a nonlinear optimization method under the given values of producer's risk, consumer's risk, acceptable quality level, and lot tolerance percent defective. Numerous tables are provided to determine the plan parameters. One real example is used to illustrate our proposed method. © 2015 John Wiley & Sons, Ltd. Source


Hsu H.-L.,Ming Chi University of Technology | Chen C.-P.,Ming Chi University of Technology | Chang J.-Y.,National Taiwan University of Science and Technology | Yu Y.-Y.,Ming Chi University of Technology | Shen Y.-K.,Ming Chi University of Technology
Nanoscale | Year: 2014

In this paper, we describe relationships between the morphologies and the power conversion efficiencies (PCE) of perovskite photovoltaics having a conventional p-i-n heterojunction structure, indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS)/CH 3NH3PbI3-xClx/PC61BM/Al. The PCE of such a device is highly dependent on the morphology of the perovskite film, which is governed by the concentrations of its precursors and the annealing conditions. A two-step annealing process allowed sufficient crystallization of the perovskite material, with a high coverage at a high precursor concentration. Relative to the device prepared using a one-step process (90 °C for 30 min), we observed a 60% increase in PCE for this optimized device. The corresponding devices exhibited extremely high stability after long-term storage (>1368 h) in the dark in a N2-filled glove box, with consistently high PCEs (AM 1.5G, 100 mW cm-2) of up to 9.1%. © 2014 the Partner Organisations. Source


Chen P.-C.,National Taiwan University of Science and Technology
Biochip Journal | Year: 2013

Microfluidics has been developed as an important platform for biochemical/chemical reactions. How to enhance the performance of a microfluidic chemical reactor is one of the core concerns when designing the microfluidic device. In the pressure-driven microfluidics without micromixer, parabolic flow profile dominates the behaviors of the laminar flow as well as the reaction particles such as DNA fragments, proteins, and enzymes. The aim of this study is to elucidate and answer a question: does a groove-shape passive micromixer improve the performance of a continuous flow type microfluidic reactor? Two mold inserts were micro-milled in the experiments, one had regular microchannels and the other one had regular microchannels with groove-shape passive micromixers, and both polymeric chips were manufactured with hot embossing techniques. Multiple experiments were realized on both chips to evaluate the groove-shape passive mixer to the performance of a continuous flow type microfluidic reactor. Polymerase chain reaction (PCR) is a typical example of chemical reaction in microfluidics, a 99 bp DNA fragment from λ-DNA was used as the target in the experiments. In this study, multiple experiments were carried out, analyzed, and concluded that the groove-shape passive mixing is not beneficial to the performance of a continuous flow type microfluidic reactor. The results showed that a regular microfluidic device without mixing had better amplification efficiency of the target DNA fragments, which indicated that using a real-time passive mixing component inside a continuous flow environment, increasing the chance of protein absorption and strengthening shear force to molecules, might cause the negative impact to the PCR reaction performance. © 2013 The Korean BioChip Society and Springer-Verlag Berlin Heidelberg. Source


Juan Y.-K.,National Taiwan University of Science and Technology | Juan Y.-K.,Stanford University | Gao P.,Tongji University | Wang J.,Stanford University
Energy and Buildings | Year: 2010

Energy consumption of buildings accounts for around 20-40% of all energy consumed in advanced countries. Over the last decade, more and more global organizations are investing significant resources to create sustainably built environments, emphasizing sustainable building renovation processes to reduce energy consumption and carbon dioxide emissions. This study develops an integrated decision support system to assess existing office building conditions and to recommend an optimal set of sustainable renovation actions, considering trade-offs between renovation cost, improved building quality, and environmental impacts. A hybrid approach that combines A* graph search algorithm with genetic algorithms (GA) is used to analyze all possible renovation actions and their trade-offs to develop the optimal solution. A two-stage system validation is performed to demonstrate the practical application of the hybrid approach: zero-one goal programming (ZOGP) and genetic algorithms are adopted to validate the effectiveness of the algorithm. A real-world renovation project is introduced to validate differences in energy performance projected for the renovation solution suggested by the system. The results reveal that the proposed hybrid system is more computationally effective than either ZOGP or GA alone. The system's suggested renovation actions would provide substantial energy performance improvements to the real project if implemented. © 2009 Elsevier B.V. Source


Hung C.-M.,National University of Tainan | Hwang G.-J.,National Taiwan University of Science and Technology | Huang I.,National University of Tainan
Educational Technology and Society | Year: 2012

Although project-based learning is a well-known and widely used instructional strategy, it remains a challenging issue to effectively apply this approach to practical settings for improving the learning performance of students. In this study, a project-based digital storytelling approach is proposed to cope with this problem. With a quasiexperiment, the proposed approach has been applied to a learning activity of a science course in an elementary school. A total of 117 Grade 5 students in an elementary school in southern Taiwan were assigned to an experimental group (N = 60) and a control group (N = 57) to compare the performance of the approach with that of conventional project-based learning. A web-based information-searching system, Meta-Analyzer, was used to enable the students to collect data on the Internet based on the questions raised by the teachers, and Microsoft's Photo Story was used to help the experimental group develop movies for storytelling based on the collected data. Moreover, several measuring tools, including the science learning motivation scale, the problem-solving competence scale and the science achievement test, were used to collect feedback as well as evaluate the learning performance of the students. The experimental results show that the project-based learning with digital storytelling could effectively enhance the students' science learning motivation, problem-solving competence, and learning achievement. © International Forum of Educational Technology & Society (IFETS). Source


Chen S.-G.,Tungnan University | Lin Y.-K.,National Taiwan University of Science and Technology
IEEE Transactions on Reliability | Year: 2012

An active research field is the evaluation of the reliability of a complex network. The most popular methods for such evaluation often use Minimal Paths (MP) or Minimal Cuts (MC) of the network. Although there are many algorithms developed to search for MP or MC, most of them are inefficient for searching a large network due to the combinatorial explosion problem. Another disadvantage is that the existing algorithms are applicable to specific counts of source and sink nodes (e.g., one-to-one, one-to-many, and so on). This article proposes a novel approach to search for all MP in a general flow network. The term general means that the approach can be used to search for all MP with multi-sources, multi-sinks in the network. The edges can be directed, undirected, or hybrid (mixed with directed and undirected arcs). Some benchmarks from the well-known algorithms in the literature are examined and compared. Moreover, the comprehensive tests are also performed with the grid networks, as well as the well-known networks in the literature to show the efficiency of the approach. A sample code is provided in the article for quick validation. © 2012 IEEE. Source


Hsu S.-H.,National Taiwan University of Science and Technology
Electronics Letters | Year: 2012

Recently mode division multiplexing has emerged to improve is transmission capacity and spectral efficiency. Interferometry is then utilised to demonstrate the intermodal group delay and intramodal dispersion simultaneously on silicon-on-insulator waveguides for high-speed applications. © 2012 The Institution of Engineering and Technology. Source


Ou Y.-C.,National Taiwan University of Science and Technology | Song J.,State University of New York at Buffalo | Lee G.C.,State University of New York at Buffalo
Earthquake Engineering and Structural Dynamics | Year: 2010

A roller seismic isolation bearing is proposed for use in highway bridges. The bearing utilizes a rolling mechanism to achieve seismic isolation and has a zero post-elastic stiffness under horizontal ground motions, a self-centering capability, and unique friction devices for supplemental energy dissipation. The objectives of this research are to investigate the seismic behavior of the proposed bearing using parametric studies (1) with nonlinear response history analysis and (2) with equivalent linear analysis according to the AASHTO guide specifications, and by comparing the results from both analysis methods (3) to evaluate the accuracy of the AASHTO equivalent linear method for predicting the peak displacement of the proposed bearing during an earthquake. Twenty-eight ground motions are used in the studies. The parameters examined are the sloping angle of the intermediate plate of the bearing, the amount of friction force for supplemental energy dissipation, and the peak ground acceleration levels of the ground motions. The peak displacement and base shear of the bearing are calculated. Results of the studies show that a larger sloping angle does not reduce the peak displacement for most of the parametric combinations without friction devices. However, for parametric combinations with friction devices, it allows for the use of a higher friction force, which effectively reduces the peak displacement, while keeping a self-centering capability. The AASHTO equivalent linear method may underestimate the peak displacement by as much as 40%. Vertical ground motions have little effect on the peak displacement, but significantly increase the peak base shear. Copyright © 2009 John Wiley & Sons, Ltd. Source


Hou H.-T.,National Taiwan University of Science and Technology
Educational Technology and Society | Year: 2012

Instructional activities based on online discussion strategies have gained prevalence in recent years. Within this context, a crucial research topic is to design innovative and appropriate online discussion strategies that assist learners in attaining a deeper level of interaction and higher cognitive skills. By analyzing the process of online discussion in depth using a specific instructional strategy, we may discover the characteristics and limitations of this strategy. This case study utilizes an online discussion activity adopting a role-playing strategy in a college course and conducts an empirical analysis to explore and evaluate both the content structure and behavioral patterns in the discussion process. We propose and adopt a new method of multi-dimensional process analysis that integrates both content and sequential analysis, whereby the dimension of interaction and cognition are analyzed simultaneously. Furthermore, we discuss the patterns, characteristics, and limitations of the roleplaying discussions and provide suggestions as references for teachers who utilize online role-playing discussion activities. © International Forum of Educational Technology & Society (IFETS). Source


Wu P.-H.,National Cheng Kung University | Hwang G.-J.,National Taiwan University of Science and Technology | Su L.-H.,National University of Tainan | Huang Y.-M.,National Cheng Kung University
Educational Technology and Society | Year: 2012

The aim of nursing education is to foster in students the competence of applying integrated knowledge with clinical skills to the application domains. In the traditional approach, in-class knowledge learning and clinical skills training are usually conducted separately, such that the students might not be able to integrate the knowledge and the skills in performing standard nursing procedures. Therefore, it is important to develop an integrated curriculum for teaching standard operating procedures in physical assessment courses. In this study, a context-aware mobile learning system is developed for nursing training courses. During the learning activities, each student is equipped with a mobile device; moreover, sensing devices are used to detect whether the student has conducted the operations on the correct location of the dummy patient's body for assessing the physical status of the specified disease. The learning system not only guides individual students to perform each operation of the physical assessment procedure on dummy patients, but also provides instant feedback and supplementary materials to them if the operations or the operating sequence is incorrect. The experimental results show that the students' learning outcomes are notably improved by utilizing the mobile learning system for nursing training. © International Forum of Educational Technology & Society (IFETS). Source


Cheng T.-H.,National Chiao Tung University | Lin Y.-D.,National Chiao Tung University | Lai Y.-C.,National Taiwan University of Science and Technology | Lin P.-C.,National Chung Cheng University
IEEE Communications Surveys and Tutorials | Year: 2012

Detecting attacks disguised by evasion techniques is a challenge for signature-based Intrusion Detection Systems (IDSs) and Intrusion Prevention Systems (IPSs). This study examines five common evasion techniques to determine their ability to evade recent systems. The denial-of-service (DoS) attack attempts to disable a system by exhausting its resources. Packet splitting tries to chop data into small packets, so that a system may not completely reassemble the packets for signature matching. Duplicate insertion can mislead a system if the system and the target host discard different TCP/IP packets with a duplicate offset or sequence. Payload mutation fools a system with a mutative payload. Shellcode mutation transforms an attacker's shellcode to escape signature detection. This study assesses the effectiveness of these techniques on three recent signature-based systems, and among them, explains why Snort can be evaded. The results indicate that duplicate insertion becomes less effective on recent systems, but packet splitting, payload mutation and shellcode mutation can be still effective against them. © 2012 IEEE. Source


Lian K.L.,National Taiwan University of Science and Technology
IEEE Transactions on Circuits and Systems I: Regular Papers | Year: 2012

An admittance or impedance matrix of a power converter is highly desirable for harmonic analysis of a power system. However, power converters are inherently nonlinear and time-varying systems. Therefore, a small-signal harmonic model needs to be derived. While there have been many methods to obtain the small-signal models of DC-DC converters, most of these methods cannot be directly applied to AC-DC converters. Moreover, while accurate methods exist for obtaining accurate models of open-loop AC-DC converters, there are few existing methods for obtaining accurate models for closed-loop AC-DC converters. This paper proposes an analytical method for obtaining an accurate small-signal harmonic model for a power converter. The proposed method is based on state-variable sensitivity methods, which have been previously used to derive a transfer function of a DC-DC converter. This paper will show what modifications are required to extend it to derive the small-signal harmonic model of a closed-loop AC-DC converter. A small-signal harmonic model of a closed-loop pulse-width modulated (PWM) voltage source converter (VSC) with synchronous $dq$ frame current controllers and a dc voltage controller is derived based on the proposed method. The results are in good agreement with large-signal simulations by means of PSCAD/EMTDC. © 2004-2012 IEEE. Source


Shieh H.-L.,National Taiwan University of Science and Technology
International Journal of Fuzzy Systems | Year: 2014

A robust validity index for fuzzy c-means (FCM) algorithm is proposed in this paper. The purpose of fuzzy clustering is to partition a given set of training data into several different clusters that can then be modeled by fuzzy theory. The FCM algorithm has become the most widely used method in fuzzy clustering. Although, there are some successful applications of FCM have been proposed, a disadvantage of FCM is that the number of clusters must be predetermined. After clustering, it is often necessary to evaluate the fitness of the results obtained by FCM. Such assessment techniques are called cluster validity. In this paper, a new cluster validity index is proposed to evaluate the fitness of clusters obtained by FCM and four examples show the results of proposed index have good performances than other cluster validities. © 2014 TFSA. Source


Wu C.-W.,National Taiwan University of Science and Technology
European Journal of Industrial Engineering | Year: 2012

Process capability indices have been widely investigated as a means of summarising process performance relative to a set of specification limits. However, most research works in the literature were restricted to handle processes with symmetric tolerances. Recently, a generalised capability index has been proposed to measure process performance with asymmetric tolerances. Consequently, in this paper we consider the problem of estimating and testing the generalised index for processes with asymmetric tolerances based on Bayesian approach. The posterior probability p for which the process with an asymmetric tolerance under investigation is capable, is derived. The credibility interval, a Bayesian analogue of the classical lower confidence interval, can also be obtained. Practitioners can use the obtained results to perform capability testing and determine whether their manufacturing processes are capable of reproducing products satisfying the preset process capability requirement whenever the manufacturing tolerance is asymmetric or symmetric. Copyright © 2012 Inderscience Enterprises Ltd. Source


Tsai R.,Chung Yuan Christian University | Huang J.S.,National Taiwan University of Science and Technology
Chemical Engineering Journal | Year: 2010

Suspended dust particles are usually correlated to indoor air quality, filtration processes, and environmental problems. Dealing with air mixed with suspended particles is a matter of great urgency. This paper presents a theoretical study on aerosol particles responding to thermophoresis, electrophoresis and the particle deposition rate onto a vertical flat wall with wall heat flux in a porous medium. The non-Darcian model is employed to analyze this process. The flow is modeled as a two-dimensional, incompressible, steady-state laminar mixed convection flow. The particle transport mechanisms are promoted by convection, Brownian diffusion, thermophoresis and electrophoresis. Similarity analysis is used to transform the governing equations for continuity, momentum, energy and concentration into a system of partial differential equations. Using numerical techniques, the particle concentration profiles and deposition velocities are obtained to improve the particle filtration technology and remove contaminants from the air. © 2009 Elsevier B.V. All rights reserved. Source


Lin C.-M.,National Taiwan University of Science and Technology
Journal of Thermal Spray Technology | Year: 2012

This study determines the optimal processing parameters for vacuum plasma spraying boron carbide (B 4C), employing an integrated approach based on the Taguchi design method, a neural network, and a genetic algorithm (GA). The proposed method comprises two stages. In the first stage, the Taguchi design method is used to establish a preliminary solution for the optimal set of processing parameters. In the second stage, the experimental results acquired from the Taguchi trials are used to construct a neural network model of the spraying process. A GA is then used to establish the optimal combination of processing parameters. The experimental results show that the coating void content of the specimen prepared using the processing parameters identified by the GA is significantly lower than that of the specimen prepared using the processing parameters identified by the Taguchi method alone. © 2012 ASM International. Source


Kono H.,University of Massachusetts Medical School | Chen C.-J.,National Taiwan University of Science and Technology | Ontiveros F.,University of Massachusetts Medical School | Rock K.L.,University of Massachusetts Medical School
Journal of Clinical Investigation | Year: 2010

Necrosis stimulates inflammation, and this response is medically relevant because it contributes to the pathogenesis of a number of diseases. It is thought that necrosis stimulates inflammation because dying cells release proinflammatory molecules that are recognized by the immune system. However, relatively little is known about the molecular identity of these molecules and their contribution to responses in vivo. Here, we investigated the role of uric acid in the inflammatory response to necrotic cells in mice. We found that dead cells not only released intracellular stores of uric acid but also produced it in large amounts postmortem as nucleic acids were degraded. Using newly developed Tg mice that have reduced levels of uric acid either intracellularly and/or extracellularly, we found that uric acid depletion substantially reduces the cell death-induced inflammatory response. Similar results were obtained with pharmacological treatments that reduced uric acid levels either by blocking its synthesis or hydrolyzing it in the extracellular fluids. Importantly, uric acid depletion selectively inhibited the inflammatory response to dying cells but not to microbial molecules or sterile irritant particles. Collectively, our data identify uric acid as a proinflammatory molecule released from dying cells that contributes significantly to the cell death-induced inflammatory responses in vivo. Source


Tien W.-H.,National Taiwan University of Science and Technology
Measurement Science and Technology | Year: 2016

The color-coded 3D micro particle tracking velocimetry system (CC3DμPTV) is a volumetric velocimetry technique that uses the defocusing digital particle image velocimetry (DDPIV) approach to reconstruct the 3D location of the particle. It is suited for microscopic flow visualization because of the single camera configuration. However, several factors limit the performance of the system. In this study, the limitation of the CC3DμPTV is discussed in detail and a new concept of a multi-camera 3D μ-PTV system is proposed to improve the performance of the original CC3DμPTV system. The system utilizes two dichroic beam splitters to separate the incoming light into 3 spectral ranges, and image with three monochrome image sensors. The use of a color-matched light source, off-center individual pinhole and monochrome image sensors allow the system to achieve better sensitivity and optical resolution. The use of coherent lasers light sources with high-speed cameras improves the velocity measurement dynamic range. The performance of the proposed multi-spectral system is first evaluated with a simulation model based on the finite element method (FEM). The performance is also compared numerically with the CC3DμPTV system. The test results show significant improvements on the signal to noise ratio and optical resolution. © 2016 IOP Publishing Ltd. Source


Sung M.-T.,Tatung University | Chang M.-H.,Tatung University | Ho M.-H.,National Taiwan University of Science and Technology
Journal of Power Sources | Year: 2014

The present work investigates the effect of cathode electrocatalysts composed of Pt nanowires (Pt-NWs) fabricated by electrospinning method and commercial Pt-loaded carbon black (Pt/C) on the oxygen reduction reaction (ORR) in a proton exchange membrane fuel cell. Pt nanowires are prepared by heating electrospun polyvinyl pyrrolidone (PVP)-Pt composite fibers at high temperatures in air atmosphere. Cathode catalyst layers with different mixing ratios of Pt-NWs and Pt/C are tested to explore their activities toward ORR. The results show that the conventional Pt/C mixed with a small amount of Pt-NWs exhibits better catalytic performance than the pure Pt/C catalysts. Under the same Pt loading of 0.5 mg cm-2, the case of composite electrocatalyst of 0.1 mg cm-2 Pt-NWs and 0.4 mg cm-2 Pt/C presents the best catalytic activities which can be rationalized by enhanced electrochemical surface area and exchange current density in the catalyst layer. The effect of Nafion content is also evaluated and the results show that the optimal content of Nafion ionomer is 30 wt% using such a composite electrocatalyst in cathode catalyst layer.© 2013 Elsevier B.V. All rights reserved. Source


Lin Y.-K.,National Taiwan University of Science and Technology
Physica A: Statistical Mechanics and its Applications | Year: 2010

This paper constructs a revised stochastic flow network to model a realistic computer network in which each arc has a lead time and a stochastic capacity. The minimum time to send a specified amount of data through the network is thus uncertain. Hence, this paper mainly proposes an approach for evaluating the system reliability that d units of data can be transmitted through k minimal paths simultaneously within the time threshold T. The idea of lower boundary points for (d, T), the minimal system states satisfying the demand d within the time threshold T, is proposed firstly. All system states meeting the time and demand requirements can be represented as the union of subsets generated from all lower boundary points for (d, T), and thus the system reliability is computed quickly. © 2009 Elsevier B.V. All rights reserved. Source


Annamalai S.K.,Vellore Institute of Technology | Palani B.,Vellore Institute of Technology | Chandrasekara Pillai K.,National Taiwan University of Science and Technology
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2012

A highly redox active and stable nano copper species immobilized functionalized-multiwalled carbon nanotube (f-MWCNT)+chitosan (CHIT) film coated glassy carbon electrode (Cuf-MWCNT+CHIT/GCE) was fabricated using a new preparation procedure, different from the conventional Cu 2++MWCNT+CHIT bulk electro-codeposition coupled glassy carbon surface activation method, for selective and sensitive amperometric estimation of H 2O 2 at -100mV vs Ag/AgCl in physiological solution. Several copper modified film electrodes with nano copper species immobilized into films made of single component or different combinations of CNT and CHIT (i.e., Cuf-MWCNT+CHIT/GCE, CuSWCNT+CHIT/GCE, Cuf-MWCNT/GCE, CuMWCNT/GCE, CuCHIT/GCE and Cu/GCE) were characterized by cyclic voltammetry in a blank pH 7 phosphate buffer solution (PBS), and only the Cuf-MWCNT+CHIT/GCE showed well-defined redox peak with an half-wave potential (E 1/2) of -85mV vs Ag/AgCl for the matrix immobilized Cu 2+/Cu + redox species with very good film stability and pronounced leaching resistance to copper. Transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray analysis, X-ray photoelectron spectroscopy were used to give a complete characterization of the Cuf-MWCNT+CHIT/GCE. Effect of potential scan rate and pH on the redox response of the Cuf-MWCNT+CHIT/GCE was studied to probe the mechanism of Cu 2+/Cu + electron transfer process. The Cuf-MWCNT+CHIT/GC electrode showed effective electrocatalytic reduction of H 2O 2 in pH 7 PBS. Amperometric i-t method of H 2O 2 detection yielded a calibration plot linear up to 125μM with a current sensitivity of 0.463AM -1cm -2. The newly developed Cuf-MWCNT+CHIT/GC electrode displayed remarkable tolerance to co-existing interferents, such as cysteine, ascorbic acid, uric acid and nitrite at the H 2O 2 detection potential in pH 7 PBS. The ability of the sensor electrode for routine analyses was demonstrated by the detection of H 2O 2 present in simulated milk samples with appreciable recovery values. © 2011 Elsevier B.V. Source


Chen R.-J.,National United University | Horng S.-J.,National Taiwan University of Science and Technology
Signal Processing: Image Communication | Year: 2010

This paper presents a novel SCAN-CA-based image security system which belongs to synchronous stream cipher. Its encryption method is based on permutation of the image pixels and replacement of the pixel values. Permutation is done by scan patterns generated by the SCAN approach. The pixel values are replaced using the recursive cellular automata (CA) substitution. The proposed image encryption method satisfies the properties of confusion and diffusion as the characteristics of SCAN and CA substitution are flexible. The salient features of the proposed image encryption method are lossless, symmetric private key encryption, very large number of secret keys, key-dependent permutation, and key-dependent pixel value replacement. Simulation results obtained using some color and gray-level images clearly demonstrate the strong performance of the proposed SCAN-CA-based image security system. © 2010 Elsevier B.V. All rights reserved. Source


Ho C.-H.,National Taiwan University of Science and Technology
Journal of Materials Chemistry | Year: 2011

β-In2S3 is a nontoxic window layer material usually used in a thin-film solar cell. Transition metal (TM)-incorporated In2S3 has been proposed to promote conversion efficiency in In2S3 because multi-photon absorption by an intermediate band (IB) would happen in the sulfide. In this paper, band-edge and photoelectric-conversion properties of Nb-substituted In2S 3 have been probed by thermoreflectance (TR), photoconductivity (PC), and photo-voltage-current (Photo V-I) measurements. The crystals of niobium-incorporated In2S3 with different Nb contents of In1.99S3:Nb0.01, In1.995S 3:Nb0.005, and undoped In2S3 were grown by chemical vapor transport (CVT) method using ICl3 as a transport agent. X-ray diffraction measurements showed that the as-grown In 2S3:Nb compounds are β-phase crystals with tetragonal structure. Lattice constants of the β-In2S3:Nb show shrinkage with the increase of the Nb content in the In2S 3. Experimental TR spectra reveal four transition features including direct gap (E0), valence band to donor (EVS), valence band to IB (EIB), and acceptor to IB [Ed(IB)] transitions detected in the Nb-substituted In2S3 compounds. The band gap (E0) shows a reduction and the crystal color changes from fresh red, to red, to dark red with increasing Nb content in the undoped β-In2S3, β-In1.995S 3:Nb0.005, and β-In1.99S 3:Nb0.01. The PC and Photo V-I measurements verified that high photoelectric-conversion efficiency occurred in the β-In 2S3 with higher niobium content. The intermediate band (IB) was formed by Nb substitution with indium in the β-In 2S3 [i.e. detected by EIB≈1.52 eV and E d(IB) ≈ 1.42 eV]. The IB state should mainly dominate the multi-photon absorption capacity and enhance the photoelectric-conversion yield in the indium sulfide. © 2011 The Royal Society of Chemistry. Source


Lin C.-M.,National Taiwan University of Science and Technology
Surface and Coatings Technology | Year: 2013

This study employed gas tungsten arc welding (GTAW) to clad an AISI 316L stainless steel surface with a buffer layer of KMS 309L stainless steel and three subsequent layers of Inconel 52M cladding. Our objective was to identify the optimal cladding parameters required to produce high-quality weldments and investigate the properties of the cladding layers. This study then used these cladding specimens to examine the effects of variation in the dilution rates of several elements on the microstructure and properties of the AISI 316L stainless steel. Our results demonstrate that repeated thermal cycles reduced the hardness of the cladding layer to less than that of the KMS 309L buffer layer and the AISI 316L stainless steel base. This was due to a decrease in overall hardness as the number of cladding layers was increased, resulting from microstructural changes in the AISI 316L stainless steel. Observations of microstructure revealed that increasing the number of cladding layers led to the formation of various solidification morphologies. The primary reason for these changes was an alteration in the composition of the stainless steel (dilution effect) produced by variations in thermal efficiency resulting from the overlapping of layers in the welded cladding. Hot cracking susceptibility tests demonstrate that AISI 316L stainless steel clad with a KMS 309L buffer layer significantly reduced susceptibility to hot cracking through the formation of δ-ferrite precipitates at the interface between the KMS 309L buffer layer and Inconel 52M. As a result, AISI 316L stainless steel clad with a KMS 309L buffer layer showed a significant reduction in susceptibility to hot cracking. © 2013 Elsevier B.V. Source


Hosseinkhani H.,National Taiwan University of Science and Technology
Current Drug Safety | Year: 2012

Three-dimensional (3D) in vitro systems that can mimic organ and tissue structure and function in vivo, will be of great benefit for a variety of biological applications from basic biology to toxicity testing and drug discovery. There have been several attempts to generate 3D tissue models but most of these models require costly equipment, and the most serious disadvantage in them is that they are too far from the mature human organs in vivo. Because of these problems, research and development in drug discovery, toxicity testing and biotech industries are highly expensive, and involve sacrifice of countless animals and it takes several years to bring a single drug/product to the market or to find the toxicity or otherwise of chemical entities. Our group has been actively working on several alternative models by merging biomaterials science, nanotechnology and biological principles to generate 3D in vitro living organs, to be called "Human Organs-on-Chip", to mimic natural organ/tissues, in order to reduce animal testing and clinical trials. We have fabricated a novel type of mechanically and biologically bio-mimicking collagen-based hydrogel that would provide for interconnected mini-wells in which 3D cell/organ culture of human samples in a manner similar to human organs with extracellular matrix (ECM) molecules would be possible. These products mimic the physical, chemical, and biological properties of natural organs and tissues at different scales. This paper will review the outcome of our several experiments so far in this direction and the future perspectives. © 2012 Bentham Science Publishers. Source


Lin S.-C.,National Taiwan University of Science and Technology | Lin P.-H.,Japan National Institute of Information and Communications Technology
IEEE Transactions on Information Forensics and Security | Year: 2013

We consider the secure transmission in ergodic fast Rayleigh fading multiple-input single-output single-antenna-eavesdropper (MISOSE) wiretap channels. We assume that the statistics of both the legitimate and eavesdropper channels are the only available channel state information at the transmitter (CSIT). By introducing a new secrecy capacity upper bound, we prove that the secrecy capacity is achieved by the Gaussian input without prefixing. To attain this result, we form another MISOSE channel for upper-bounding by relaxing the equivocation constraint, and tighten the bound by carefully selecting correlations between the legitimate and eavesdropper channel gains. The resulting upper bound is tighter than the others in the literature which are based on modifying the correlation between the noises at the legitimate receiver and eavesdropper. Next, we fully characterize the secrecy capacity by showing that the optimal channel input covariance matrix is a scaled identity matrix. The key to solve such a stochastic optimization problem is by exploiting the completely monotone property of the secrecy capacity. Finally, we prove that with only statistical CSIT of both channels, the capacity will neither scale with signal-to-noise ratio (SNR) nor the number of antenna. Our numerical results also match these observations and further confirm that having the legitimate CSIT (realizations) is very beneficial to increase the secrecy capacity. © 2005-2012 IEEE. Source


Liu J.-J.,Shih Hsin University | Wang Y.-L.,National Taiwan University of Science and Technology
Information Sciences | Year: 2014

Let F be a set of faulty edges in hypercube Qn with |F|≤3n-8 for n≥5. We prove that there still exists a fault-free Hamiltonian cycle in Qn if the following two conditions are satisfied: (1) the degree of every vertex is at least two, and (2) there do not exist a pair of nonadjacent vertices in a 4-cycle whose degrees are both two after faulty edges are removed. © 2013 Elsevier Inc. All rights reserved. Source


Liu J.S.,National Taiwan University of Science and Technology | Lu L.Y.Y.,Yuan Ze University
Journal of the American Society for Information Science and Technology | Year: 2012

This study enhances main path analysis by proposing several variants to the original approach. Main path analysis is a bibliometric method capable of tracing the most significant paths in a citation network and is commonly used to trace the development trajectory of a research field. We highlight several limitations of the original main path analysis and suggest new, complementary approaches to overcome these limitations. In contrast to the original local main path, the new approaches generate the global main path, the backward local main path, multiple main paths, and key-route main paths. Each of them is obtained via a perspective different from the original approach. By simultaneously conducting the new, complementary approaches, one uncovers the key development of the target discipline from a broader view. To demonstrate the value of these new approaches, we simultaneously apply them to a set of academic articles related to the Hirsch index. The results show that the integrated approach discovers several paths that are not captured by the original approach. Among these new approaches, the key-route approach is especially useful and hints at a divergence-convergence-divergence structure in the development of the Hirsch index. © 2011 ASIS&T. Source


Sheng M.L.,National Taiwan University of Science and Technology | Teo T.S.H.,National University of Singapore
International Journal of Information Management | Year: 2012

There are studies showing that utilitarian (perceived ease of use and perceived usefulness) and hedonic (entertainment and aesthetics) attributes of products are two fundamental resources that ensure brand equity in the mobile domain. However, few studies examine the attributes of products and how and why such resources influence mobile brand equity. In this study, a survey was carried out on 262 mobile users in Taiwan to examine the mediating effects of customer experience on the relationship between product attributes on mobile brand equity. Our findings suggest that utilitarian and hedonic attributes of products affect mobile brand equity through customer experience. In other words, perceived ease of use, perceived usefulness, entertainment, and aesthetics may not be intrinsic value; their value on mobile brand equity is realized through customer experience. However, whereas the effect of perceived ease of use on mobile brand equity is partially mediated, perceived usefulness, entertainment, and aesthetics are fully mediated by customer experience. By showing the differential effects of product attributes on mobile brand equity, this study provides a more refined understanding of the interplay among product attributes, customer experience, and mobile brand equity. The results suggest that by overlooking the mediating role of customer experience, previous research may have provided an overly optimistic view of the value of product attributes in mobile brand equity. © 2011 Elsevier Ltd. All rights reserved. Source


Kuo F.-R.,National University of Tainan | Hwang G.-J.,National Taiwan University of Science and Technology | Lee C.-C.,Fooyin University
Computers and Education | Year: 2012

Fostering problem-solving abilities has long been recognized as an important issue in education; however, past studies have shown that it is difficult and challenging to find effective learning strategies or tools for improving students' problem-solving abilities. To cope with this problem, in this study, a hybrid approach that integrates the cognitive apprenticeship model with the collaborative learning strategy is proposed for conducting web-based problem-solving activities. Students' problem-solving performance is examined in such a hybrid learning context. Furthermore, past studies indicate that cognitive load could affect learners' performance; thus, the influence of cognitive load on students' problem-solving effectiveness with this new approach is investigated in depth. The experimental results show that middle- and low-achievement students in the experimental group gained significant benefits from the hybrid approach in comparison with those who learned with the traditional approach. Accordingly, a discussion of how to accommodate the needs of different learning ability groups is provided. © 2011 Elsevier Ltd. All rights reserved. Source


Liu T.-C.,National Central University | Lin Y.-C.,National Central University | Tsai M.-J.,National Taiwan University of Science and Technology | Paas F.,Erasmus University Rotterdam | Paas F.,University of Wollongong
Computers and Education | Year: 2012

This study investigated split-attention and redundancy effects in a mobile learning environment on leaf morphology of plants as a function of different combinations of media. Eighty-one fifth-grade students were randomly assigned to the following three conditions: texts with pictures embedded in the mobile device (TP condition); texts embedded in the mobile device and real objects that are outside of the mobile device (TO condition); and texts with pictures embedded in the mobile device and real objects that are outside of the mobile device (TPO condition). Differences in performance on comprehension tests and learning efficiency were examined across conditions. The TP condition was expected to perform better than the TO condition due to a split-attention effect. The TP and TO conditions were expected to perform better than the TPO condition due to a redundancy effect. The results indicated no difference between the TP and the TO condition in comprehension and learning efficiency, but the TP and TO conditions performed better than the TPO condition on both measures. The implications of the results for research and design of mobile learning environments are discussed. © 2011 Elsevier Ltd. All rights reserved. Source


Lin C.-C.,National Central University | Tsai C.-C.,National Taiwan University of Science and Technology
International Journal of Computer-Supported Collaborative Learning | Year: 2012

This study aimed to investigate the relationships between college students' behavioral and cognitive engagements while performing an online collective information searching (CIS) activity. The activity aimed to assist the students in utilizing a social bookmarking application to exploit the Internet in a collective manner. A group of 101 college students in Taiwan participated in the research procedure, and performed the CIS activity to glean quality online resources for the given search assignment. The actions taken and annotations and comments made during the activity were recorded as log data, and used as the main resource for later analyses of behavioral and cognitive engagements in the activity. Through cluster analysis of the students' contributions to the CIS activity, four categories of behavioral engagement were identified, namely "Hitchhiker," "Individualist," "Active" and "Commentator," to represent the students' investments in performing the activity. Furthermore, to explore the students' cognitive engagement in the activity, content analysis of the verbal transcripts of their annotations and comments was conducted based on the refined coding framework of the present study. The results of further cluster analysis revealed that the students' cognitive engagement levels could be identified as "Deep" and "Surface." Through comparison of their behavioral and cognitive engagements, the findings revealed that the students with "Active" behavioral engagement tended to exhibit a "Deep" level of cognitive engagement. It is therefore suggested that both behavioral and cognitive engagements are critical to participatory learning with practice in CIS activities. © 2012 International Society of the Learning Sciences, Inc. and Springer Science+Business Media New York. 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


Shen C.,Beijing Jiaotong University | Shen C.,Xidian University | Li W.-C.,National Tsing Hua University | Chang T.-H.,National Taiwan University of Science and Technology
IEEE Transactions on Signal Processing | Year: 2014

This paper considers the transmitter design for wireless information and energy transfer (WIET) in a multiple-input single-output (MISO) interference channel (IFC). The design problem is to maximize the system throughput subject to individual energy harvesting constraints and power constraints. It is observed that the ideal scheme, where the receivers simultaneously perform information detection (ID) and energy harvesting (EH) from the received signal, may not always achieve the best tradeoff between information transfer and energy harvesting, but simple practical schemes based on time splitting may perform better. We therefore propose two practical time splitting schemes, namely the time-division mode switching (TDMS) and time-division multiple access (TDMA), in addition to the existing power splitting (PS) scheme. In the two-user scenario, we show that beamforming is optimal to all the schemes. Moreover, the design problems associated with the TDMS and TDMA schemes admit semi-analytical solutions. In the general K -user scenario, a successive convex approximation method is proposed to handle the WIET problems associated with the ideal scheme, the PS scheme and the TDMA scheme, which are known NP-hard in general. Simulation results show that none of the schemes under consideration can always dominate another in terms of the sum rate performance. Specifically, it is observed that stronger cross-link channel power improves the achievable sum rate of time splitting schemes but degrades the sum rate performance of the ideal scheme and PS scheme. As a result, time splitting schemes can outperform the ideal scheme and the PS scheme in interference dominated scenarios. © 1991-2012 IEEE. Source


Kuo C.,National Taiwan University of Science and Technology | Dai J.S.,Kings College London
Journal of Medical Devices, Transactions of the ASME | Year: 2012

A crucial design challenge in minimally invasive surgical (MIS) robots is the provision of a fully decoupled four degrees-of-freedom (4-DOF) remote center-of-motion (RCM) for surgical instruments. In this paper, we present a new parallel manipulator that can generate a 4-DOF RCM over its end-effector and these four DOFs are fully decoupled, i.e., each of them can be independently controlled by one corresponding actuated joint. First, we revisit the remote center-of-motion for MIS robots and introduce a projective displacement representation for coping with this special kinematics. Next, we present the proposed new parallel manipulator structure and study its geometry and motion decouplebility. Accordingly, we solve the inverse kinematics problem by taking the advantage of motion decouplebility. Then, via the screw system approach, we carry out the Jacobian analysis for the manipulator, by which the singular configurations are identified. Finally, we analyze the reachable and collision-free workspaces of the proposed manipulator and conclude the feasibility of this manipulator for the application in minimally invasive surgery. © 2012 American Society of Mechanical Engineers. Source


Liu G.-Z.,National Cheng Kung University | Liu Z.-H.,National Cheng Kung University | Hwang G.-J.,National Taiwan University of Science and Technology
Computers and Education | Year: 2011

Many English learning websites have been developed worldwide, but little research has been conducted concerning the development of comprehensive evaluation criteria. The main purpose of this study is thus to construct a multi-dimensional set of criteria to help learners and teachers evaluate the quality of English learning websites. These evaluation guidelines are based on web usability, learning materials, functionality of assisting language learning, technology integration, and learner preferences. In order to achieve this goal, the researchers used a rigorous four-phase procedure and utilized both qualitative and quantitative research methods with university students and professors in Design-based Research to construct and refine the evaluation criteria in 2008-2009. Fifty-eight evaluation criteria were refined and finalized. In addition, to cope with the difficulties in applying the derived criteria and explaining what the results indicate, this study presents a practical application by evaluating an English learning website. © 2010 Elsevier Ltd. All rights reserved. Source


Chen T.-T.,National Quemoy University | Leu S.-S.,National Taiwan University of Science and Technology
Safety Science | Year: 2014

Fall or tumble is one of the most common accidents in bridge construction. Failing to implement safety management and training effectively may result in serious occupational accidents. Current site safety management relies mostly on checklist evaluation; however, its effectiveness is limited by the experience and the abilities of the evaluators, which may not consistently achieve the goal of thorough assessment. Recently, several systematic safety risk assessment approaches, such as Fault Tree Analysis (FTA) and Failure Mode and Effect Criticality Analysis (FMECA), have been used to evaluate safety risks at bridge projects. However, these traditional methods ineffectively address dependencies among safety factors at various levels that fail to provide early warnings to prevent occupational accidents. In order to overcome the limitations of the traditional approach, in this paper a fall risk assessment model for bridge construction projects is developed by establishing a Bayesian network (BN) based on Fault Tree (FT) transformation. The model was found to provide much better site safety management ability by enabling better understanding of the probability of fall risks through the analysis of fall causes and their relationships in a BN. The system has been used to analyze and verify safety practices at five cantilever bridge construction projects currently under construction in Taiwan. It was found that BN analysis is consistent with the conventional safety performance assessment. In practice, based upon the BN analysis by inputting prior information about the site safety management, the probabilities of fall risks and their sensitive factors can be effectively assessed. Proper preventive safety management strategies could then be established to reduce the occurrences of fall accidents at the bridge construction projects. © 2014 Elsevier Ltd. Source


Chiu C.-R.,National Taiwan University of Science and Technology | Liou J.-L.,Chung Hua Institution for Economic Research | Wu P.-I.,National Taiwan University | Fang C.-L.,National Taipei University
Energy Economics | Year: 2012

In this paper, we present an alternative analysis framework to evaluate the effects of technology heterogeneities and undesirable output on environmental efficiency measurement. The proposed framework combines the directional distance function and a meta-frontier analysis. It can be used to measure efficiency improvements brought about by enhanced technical management and technological advances. For demonstration purposes, we used the framework to measure the environmental efficiency in 90 countries worldwide for the 2003-2007 period. The results showed that when the meta-technology set is used as the evaluation basis, the average environmental efficiency of high competitiveness countries is greater than that of lower-middle, low, and upper-middle competitiveness countries. The upper-middle competitiveness countries perform worse than the lower-middle and low competitiveness countries because of the excessive labor force usage and carbon dioxide emissions in these countries. We also found that the environmental inefficiency of the meta-frontier for high competitiveness countries can be attributed to managerial failure in the production process, whereas that for upper-middle, lower-middle, and low competitiveness countries can be attributed to technological differences. © 2012 Elsevier B.V. Source


Lee S.W.-Y.,National Changhua University of Education | Tsai C.-C.,National Taiwan University of Science and Technology
Computers in Human Behavior | Year: 2011

This study aims to investigate students' perceptions of three aspects of learning - collaboration, self-regulated learning (SRL), and information seeking (IS) in both Internet-based and traditional face-to-face learning contexts. A multi-dimensional questionnaire was designed to evaluate each aspect in terms of perceived capability, experience, and interest. The analyses explore (1) potential differences of students' perceptions between Internet-based and face-to-face learning environments and (2) potential differences in the three aspects in relation to learners' attributes and the use of the Internet and enrollment in online courses. This study surveyed students in a higher education institute who had had experiences with Internet-based and face-to-face learning. The results showed that students perceived higher levels of collaboration (capability only), SRL (capability and experience) and IS (capability, interest, and experience) in Internet-based learning than in traditional learning environments. In terms of students' education level, graduate students perceived higher levels of capabilities and interests in some of the aspects, than undergraduate students. In addition, for Internet-based learning, significant differences in collaboration and SRL were found derived from time spent on the Internet related to learning; and students' perceptions of collaboration, SRL, and IS were all positively correlated to students' online course-taking experience. Implications for online learning practices and instructor's facilitation are discussed. © 2010 Elsevier Ltd. All rights reserved. Source


Yang C.-I.,Academia Sinica, Taiwan | Chuang P.-H.,Academia Sinica, Taiwan | Chuang P.-H.,National Taiwan University of Science and Technology | Lu K.-L.,Academia Sinica, Taiwan
Chemical Communications | Year: 2011

A homospin ladder-like chain, [Co(Hdhq)(OAc)]n (1; H 2dhq = 2,3-dihydroxyquinoxaline), shows a single-chain-magnet-like (SCM-like) behavior with the characteristics of frequency dependence of the out-of-phase component in alternating current (ac) magnetic susceptibilities and hysteresis loops. © 2011 The Royal Society of Chemistry. Source


Hwang G.-J.,National Taiwan University of Science and Technology | Chang H.-F.,National University of Tainan
Computers and Education | Year: 2011

The advancement of mobile and wireless communication technologies has encouraged an increasing number of studies concerning mobile learning, in which students are able to learn via mobile devices without being limited by space and time; in particular, the students can be situated in a real-world scenario associated with the learning content. Although such an approach seems interesting to the students, researchers have emphasized the need for well-designed learning support in order to improve the students' learning achievements. Therefore, it has become an important issue to develop methodologies or tools to assist the students to learn in a mobile learning environment. Based on this perspective, this study proposes a formative assessment-based approach for improving the learning achievements of students in a mobile learning environment. A mobile learning environment has been developed based on this approach, and an experiment on a local culture course has been conducted in southern Taiwan to evaluate its effectiveness. The experimental results show that the proposed approach not only promotes the students' learning interest and attitude, but also improves their learning achievement. © 2010 Elsevier Ltd. All rights reserved. Source


Lin P.-C.,National Taiwan Normal University | Hou H.-T.,National Taiwan University of Science and Technology | Wang S.-M.,Chinese Culture University | Chang K.-E.,National Taiwan Normal University
Computers and Education | Year: 2013

In recent years, social networking services (SNSs), for example, Facebook, have shown exponential growth in their number of users. Witnessing the popularity of these SNSs, educational researchers have also explored the potential educational value of using SNSs. Despite the few studies that have investigated learners' attitudes toward and the effects of incorporating SNSs in class, limited attention has been paid to examining learners' knowledge and cognitive processes involved in online discussions using SNSs. Although general public interest in life-long learning has been gradually increasing, relatively little attention has been devoted to exploring the application of SNSs in adult and continuing education programs. To promote a better understanding of using SNSs in learning, this study seeks to explore learners' online discussion behaviors in an art course that involved a project-based learning activity using a popular SNS, Facebook, to support students' asynchronous online discussions. The participants in our study included 62 students enrolled in the school of continuing education at a university in northern Taiwan. Adapting the Revised Bloom's Taxonomy as a coding scheme, this study employed a quantitative content analysis (QCA) and lag sequential analysis (LSA) to examine the content and behavioral patterns of students' discussions. The results indicate that the most prominent knowledge dimension in students' discussions is the meta-cognitive knowledge, while the cognitive process is primarily focused on understanding and comprehension. In addition, a moderate proportion of off-topic discussion was found in this study. Considering the different behaviors that may be exhibited by members of varied age and gender, a further analysis based on students' individual differences was conducted. The results showed that, in the context of online discussions, female and older learners are more likely to engage in off-topic discussions. Based on these findings, this study suggests that when conducting online discussion activities using SNSs, instructors should consider the characteristics of adult learners and their individual differences and design their teaching activities accordingly. Implications and limitations of this study are discussed, and pedagogical suggestions for adapting SNSs to teaching activities for adult and continuing education are proposed. © 2012 Elsevier Ltd. All rights reserved. Source


Tung F.-W.,National Taiwan University of Science and Technology
Interactive Learning Environments | Year: 2013

The potential for involving emotions in human-technology interaction has received considerable attention in many fields of design, as it has many implications in the design of educational applications to improve learner-computer interaction. This study attempted to create emotionally supportive learning environments by adding emotional feedback through cues from vocal and facial expression. Faces and voices are powerful sources of emotional information through visual and auditory modalities, the two main components of multimedia. Two quasi-experiments were conducted to investigate the impact of visual and auditory emotional feedback on the instruction of school-age children with regard to their perceived social presence, intrinsic motivation, and performance during the learning process. The independent variables in the first experiment were speech and static facial expression. A total of 173 sixth graders participated in the experiments. Results of the first experiment demonstrated that children preferred the auditory modality of speech to the visual modality of facial expression. In the second experiment, the independent variables were speech and dynamic facial expression. The findings revealed no significant differences between speech and dynamic facial expression, indicating that emotional feedback through audio displays or visual displays could function equally in the social perceptions of children, and help to motivate them in learning activities. Dynamic facial expression and speech work alternately. The findings of this study may help designers to create emotionally supportive learning environments for children, using emotional feedback through speech and facial expression. © 2013 Copyright Taylor and Francis Group, LLC. Source


Lee Y.-J.,National Taiwan University of Science and Technology | Yeh Y.-R.,National Taiwan University | Wang Y.-C.F.,Academia Sinica, Taiwan
IEEE Transactions on Knowledge and Data Engineering | Year: 2013

Anomaly detection has been an important research topic in data mining and machine learning. Many real-world applications such as intrusion or credit card fraud detection require an effective and efficient framework to identify deviated data instances. However, most anomaly detection methods are typically implemented in batch mode, and thus cannot be easily extended to large-scale problems without sacrificing computation and memory requirements. In this paper, we propose an online oversampling principal component analysis (osPCA) algorithm to address this problem, and we aim at detecting the presence of outliers from a large amount of data via an online updating technique. Unlike prior principal component analysis (PCA)-based approaches, we do not store the entire data matrix or covariance matrix, and thus our approach is especially of interest in online or large-scale problems. By oversampling the target instance and extracting the principal direction of the data, the proposed osPCA allows us to determine the anomaly of the target instance according to the variation of the resulting dominant eigenvector. Since our osPCA need not perform eigen analysis explicitly, the proposed framework is favored for online applications which have computation or memory limitations. Compared with the well-known power method for PCA and other popular anomaly detection algorithms, our experimental results verify the feasibility of our proposed method in terms of both accuracy and efficiency. © 1989-2012 IEEE. Source


Hsu C.-K.,National Taiwan Normal University | Hwang G.-J.,National Taiwan University of Science and Technology | Chang C.-K.,National University of Tainan
Computers and Education | Year: 2013

In this paper, a personalized recommendation-based mobile language learning approach is proposed. A mobile learning system has been developed based on the approach by providing a reading material recommendation mechanism for guiding EFL (English as Foreign Language) students to read articles that match their preferences and knowledge levels, and a reading annotation module that enables students to take notes of English vocabulary translations for the reading content in individual or shared annotation mode. To evaluate the effectiveness of the proposed approach, an experiment was conducted on a senior high school English course by assigning three classes of students to two experimental groups and a control group. One experimental group learned with the recommendation system with the individual annotation function, the other experimental group learned with the recommendation system with the shared annotation function, while the students in the control group learned with the individual annotation function, but without the recommendation system. The experimental results show that both experimental groups outperformed the control group, but there was no difference in learning outcome between the two experimental groups in terms of learning achievements. © 2012 Elsevier Ltd. All rights reserved. Source


Chang T.-H.,National Taiwan University of Science and Technology | Alizadeh M.,University of California at Davis | Scaglione A.,University of California at Davis
IEEE Transactions on Smart Grid | Year: 2013

It is anticipated that an uncoordinated operation of individual home energy management (HEM) systems in a neighborhood would have a rebound effect on the aggregate demand profile. To address this issue, this paper proposes a coordinated home energy management (CoHEM) architecture in which distributed HEM units collaborate with each other in order to keep the demand and supply balanced in their neighborhood. Assuming the energy requests by customers are random in time, we formulate the proposed CoHEM design as a multi-stage stochastic optimization problem. We propose novel models to describe the deferrable appliance load [e.g., plug-in (hybrid) electric vehicles (PHEV)], and apply approximation and decomposition techniques to handle the considered design problem in a decentralized fashion. The developed decentralized CoHEM algorithm allow the customers to locally compute their scheduling solutions using domestic user information and with message exchange between their neighbors only. Extensive simulation results demonstrate that the proposed CoHEM architecture can effectively improve real-time power balancing. Extensions to joint power procurement and real-time CoHEM scheduling are also presented. © 2010-2012 IEEE. Source


Chung T.-P.,Jilin University | Liao C.-J.,National Taiwan University of Science and Technology
Applied Soft Computing Journal | Year: 2013

We consider the n-job, k-stage problem in a hybrid flow shop (HFS) with the objective of minimizing the maximum completion time, or makespan, which is an NP-hard problem. An immunoglobulin-based artificial immune system algorithm, called IAIS algorithm, is developed to search for the best sequence. IAIS, which is better fit the natural immune system, improves the existing AIS by the process before/after encounter with antigens. Before encounter with antigens, a new method of somatic recombination is presented; after encounter with antigens, an isotype switching is proposed. The isotype switching is a new approach in artificial immune system, and its purpose is to produce antibodies with the same protection but different function to defense the antigen. To verify IAIS, comparisons with the existing immune-based algorithms and other non-immune-based algorithms are made. Computational results show that IAIS is very competitive for the hybrid flow shop scheduling problem. © 2013 Elsevier B.V. All rights reserved. Source


Tao T.,Taipei Chengshih University of Science and Technology | Su S.-F.,National Taiwan University of Science and Technology
Applied Soft Computing Journal | Year: 2011

In this paper, a novel scheme of incorporating a learning mechanism into previous step supervisory controllers for adaptive fuzzy control is proposed to relax bounds required in the control process. In traditional supervisory adaptive fuzzy control approaches, the use of fuzzy estimators for approximating system functions and a robust supervisory control law are necessary to deal with any possible uncertainties caused in the system. This kind of supervisory controller depends on the robust bounds of system functions so that it can ensure the Lyapunov stability of controlled systems. However, in those approaches, the output may not be able to follow the reference trajectory well if the robust bounds are predicted improperly. In our implementation, CMAC (Cerebellar Model Articulation Controllers) is used as the learning mechanism because of its quick learning capability. Under the Lyapunov stable criterion, the proposed CMAC learning mechanism can improve the output performance and can relax the robust bound limitation so that practical systems can easily be realized. In summary, the proposed approach not only can relax bounds for previous step supervisory controllers in adaptive fuzzy control, but also can significantly improve the control performance of the system. © 2011 Elsevier B.V. All rights reserved. Source


In some higher education courses that focus on case studies, teachers can provide situated scenarios (such as business bottlenecks and medical cases) and problem-solving discussion tasks for students to promote their cognitive skills. There is limited research on the content, performance, and behavioral patterns of teaching using online discussions and integrated situated scenarios. This case study empirically explored the learning process of adopting collaborative online instructional discussion activities for the purpose of problem-solving using situated scenarios in a higher education course. Thirty-two university students carried out problem-solving activities on case scenarios and problem-solving tasks assigned by the teacher on the discussion forum. Two forms of instructional activities were considered: 1) problem-solving in a given scenario and 2) problem-solving when learners play roles in a given scenario. The activities mentioned above were each implemented for a week. Using analytical methods that combined qualitative and quantitative approaches, we conducted quantitative content analysis, qualitative protocol analysis, and cluster analysis. We compared the differences in the quality of discussions, patterns of cognitive structure, and patterns of the clusters of possible discussion behaviors. Our study suggests that, when compared to general situated learning activity, discussions are of better quality when they involve a role-playing activity, which also yields the most diverse options for solutions. However, when learners engage in either approach to situated learning, the cognitive aspects of application, evaluation, and innovation are often still found lacking. Our study discusses the observed behavioral patterns and learning-related limitations of these activities and provides specific recommendations for teachers and researchers. © 2010 Elsevier Ltd. All rights reserved. Source


Chen M.-C.,National Taitung University | Chen J.-L.,National Taiwan University of Science and Technology | Chang T.-W.,National Taiwan University
Computer Communications | Year: 2011

With the enormous market potential of the telematics industry and the rapid development of information technology, automotive telematics has attracted considerable attention for mobile computing and Intelligent Transport Systems (ITSs). However, as a result of varied platform standards, not all telematics services can be used in telematics terminals. The main issues are that most telematics technologies depend on vertical, proprietary, and closed Original Equipment Manufacturer (OEM) platforms. These platforms form islands of non-interoperable technology and prevent third-party service providers from creating valuable services. This study integrates the Open Gateway Service Initiative Vehicle Expert Group (OSGi/VEG) into an Android platform to generate a vehicular Android/OSGi platform that has the advantages of both original platforms. These features include remote management, rich class-sharing, proprietary vehicular applications, security policies, easy management of Application Programming Interface (APIs), and an open environment. This study also integrates a cloud computing mechanism into the Android/OSGi platform, allowing service providers to upload their telematics bundles onto storage clouds using a provisioning server. A management agent in the Android/OSGi platform can simultaneously update its application service modules using remote storage clouds and use visual intelligence to continually change the distinguishing features of applications based on context-awareness without user intervention. To assess the feasibility of the proposed Android/OSGi platform, this study presents a vehicular testbed to determine the functionalities of different telematics applications. Android/OSGi platform applications require less memory and system resources than those on the original Android platform when performing complicated operations. Additionally, the Android/OSGi platform launches telematics services more quickly than the original Android platform. The proposed platform overcomes the problem of frequent non-responsive exceptions in the original Android platform. © 2010 Elsevier B.V. All rights reserved. Source


Hsieh S.-W.,Far East University of Taiwan | Jang Y.-R.,National Sun Yat - sen University | Hwang G.-J.,National Taiwan University of Science and Technology | Chen N.-S.,National Sun Yat - sen University
Computers and Education | Year: 2011

Ubiquitous learning (u-learning), in conjunction with supports from the digital world, is recognized as an effective approach for situating students in real-world learning environments. Earlier studies concerning u-learning have mainly focused on investigating the learning attitudes and learning achievements of students, while the causations such as learning style and teaching style were usually ignored. This study aims to investigate the effects of teaching styles and learning styles on reflection levels of students within the context of u-learning. In particular, we investigated the teaching styles at the dimensions of brainstorming and instruction and recall and the learning styles at the dimensions of active and reflective learning. The experiment was conducted with 39 fifth grader students at an elementary school in southern Taiwan. A u-learning environment was established at a butterfly ecology garden to conduct experiments for natural science courses. The experimental results of one-way ANCOVA show that those students who received a matching teaching-learning style presented a significant improvement in their reflection level. That is, matching the learning styles of students with the appropriate teaching styles can significantly improve students' reflection levels in a u-learning environment. © 2011 Elsevier Ltd. All rights reserved. Source


Hou H.-T.,National Taiwan University of Science and Technology | Wu S.-Y.,National Central University
Computers and Education | Year: 2011

Online discussions have been widely utilized as an educational activity, and much research has been conducted on the process and behaviors involved in asynchronous discussions. However, research on behavioral patterns in learners' synchronous discussions, including the process of social knowledge construction and project coordination is limited. Through the examination of the behavioral patterns and differences between students with high- and low-quality discussions, it may be possible to understand the limitations of knowledge construction in synchronous discussions. Furthermore, these findings may help teachers design and guide synchronous discussions activities. This study is an empirical case study in which college students conducted synchronous discussions based on topics specified by the teacher. The students used a text-based instant messaging (IM) tool in a period of 98 days. Two analytical methods were employed. The coding of the discussion messages was followed by a quantitative content analysis and a lag sequential analysis of behaviors. The social knowledge construction, project coordination, and social interactions in the group discussion were explored. Furthermore, the differences between the behavioral patterns of the high- and low-quality discussion groups were also examined. The findings indicate that although more than half of the discussion messages were off-topic, there were also some knowledge construction behavioral sequences. Furthermore, there were several limitations on the diversity and depth of the knowledge construction in the students' discussions. The high-quality discussion teams performed better than the low-quality discussion teams in terms of participation, diversity in knowledge construction, and coordination. However, they also had more off-topic discussions. In this paper, we discuss these behavioral patterns and provide specific suggestions for teachers regarding how to implement synchronous discussions that are targeted to students' knowledge construction processes. © 2010 Elsevier Ltd. All rights reserved. Source


Chen C.-L.,National Chiao Tung University | Tseng F.S.C.,National Taiwan University of Science and Technology | Liang T.,National Chiao Tung University
Knowledge and Information Systems | Year: 2011

With the rapid growth of text documents, document clustering technique is emerging for efficient document retrieval and better document browsing. Recently, some methods had been proposed to resolve the problems of high dimensionality, scalability, accuracy, and meaningful cluster labels by using frequent itemsets derived from association rule mining for clustering documents. In order to improve the quality of document clustering results, we propose an effective Fuzzy Frequent Itemset-based Document Clustering (F2IDC) approach that combines fuzzy association rule mining with the background knowledge embedded in WordNet. A term hierarchy generated from WordNet is applied to discover generalized frequent itemsets as candidate cluster labels for grouping documents. We have conducted experiments to evaluate our approach on Classic4, Re0, R8, and WebKB datasets. Our experimental results show that our proposed approach indeed provide more accurate clustering results than prior influential clustering methods presented in recent literature. © 2010 Springer-Verlag London Limited. Source


Lee D.-J.,National Taiwan University of Science and Technology | Lee D.-J.,National Taiwan University | Wong B.-T.,National Taiwan University
Bioresource Technology | Year: 2014

Denitrifying sulfide removal (DSR) process simultaneously removes nitrate, sulfide and organic matters in the same reactor. This study isolated eight DSR strains and composed a microbial consortium to reveal the stoichiometry and kinetics of autotrophic, heterotrophic and mixotrophic denitrification (DSR). A novel kinetic diagram based on mass and electron balances was proposed to graphically interpret the system kinetics and identify the accessible regime where DSR reactions can be applied. Demonstration of the use of the proposed diagram showed the easy assessment of DSR system performance by the status on the diagram. © 2014 Elsevier Ltd. Source


Lin P.-H.,National Taiwan University | Lin P.-H.,Japan National Institute of Information and Communications Technology | Lai S.-H.,MStar Semiconductor Inc. | Lin S.-C.,National Taiwan University of Science and Technology | Su H.-J.,National Taiwan University
IEEE Journal on Selected Areas in Communications | Year: 2013

In this paper we consider the secure transmission with multiple-input, single-output, single-antenna eavesdropper (MISOSE) in fast fading channels where the transmitter knows perfect legitimate channel state information but only the statistics of the eavesdropper's channel. For the MISOSE channels, the artificial noise assisted beamforming proposed by Goel and Negi is a promising technique, where the artificial noise is imposed on the null space of the legitimate channel to disrupt the eavesdropper's reception. Here we propose a generalized artificial noise scheme which allows the injection of the artificial noise to the legitimate channel. Although the generalized artificial noise may cause the leakage of artificial noise at the legitimate receiver, the secrecy rate can still be improved since the covariance matrix of it is more flexible than the heuristic one selected by Goel and Negi. To fully characterize the proposed scheme, we investigate the optimization of its secrecy rate. We first derive the conditions under which the beamformers of the message bearing signal and the generalized artificial noise being the same is optimal. Based on this choice, the complicated secrecy rate optimization problem over the covariance matrices of the message-bearing signal and the generalized artificial noise can be reduced to a much simpler power allocation problem. We also develop an efficient algorithm to solve this non-convex power allocation problem. Numerical results show that our generalized artificial noise scheme outperforms Goel and Negi's heuristic selection, especially in the near eavesdropper settings. In particular, with the aid of the proposed scheme, the regime with non-zero secrecy rate is enlarged, which can significantly improve the connectivity of the network. © 1983-2012 IEEE. Source


Hwang G.J.,National Taiwan University of Science and Technology | Wu P.H.,National Cheng Kung University | Zhuang Y.Y.,National University of Tainan | Huang Y.M.,National Cheng Kung University
Interactive Learning Environments | Year: 2013

The advancement of mobile device and wireless communication technologies is having a great influence on the design concept of learning activities. In this study, we attempt to integrate field study into the inquiry-based mobile learning model; moreover, a mobile learning environment that allows students to access both physical and virtual resources is developed accordingly. During the in-field learning activity, the mobile learning system is able to present the learning tasks, guide the students to visit the real-world learning targets for exploration, and provide them with supplementary materials via the mobile devices. The aim of this research focuses on the effects of this mobile learning model on students' cognitive load and learning achievements. The 51 sixth graders who participated in this research were assigned to an experimental and a control group. From the pre and posttests as well as the cognitive load questionnaire, it was found that the students who learned with the inquiry-based mobile learning approach had better learning achievement and less cognitive load than those who learned with the traditional approach. Therefore, it is concluded that the mobile learning model has positive effects on elementary students in local culture learning. © 2013 Copyright Taylor and Francis Group, LLC. Source


Wu H.-K.,National Taiwan Normal University | Lee S.W.-Y.,National Changhua University of Education | Chang H.-Y.,National Kaohsiung Normal University | Liang J.-C.,National Taiwan University of Science and Technology
Computers and Education | Year: 2013

Although augmented reality (AR) has gained much research attention in recent years, the term AR was given different meanings by varying researchers. In this article, we first provide an overview of definitions, taxonomies, and technologies of AR. We argue that viewing AR as a concept rather than a type of technology would be more productive for educators, researchers, and designers. Then we identify certain features and affordances of AR systems and applications. Yet, these compelling features may not be unique to AR applications and can be found in other technological systems or learning environments (e.g., ubiquitous and mobile learning environments). The instructional approach adopted by an AR system and the alignment among technology design, instructional approach, and learning experiences may be more important. Thus, we classify three categories of instructional approaches that emphasize the "roles," "tasks," and "locations," and discuss what and how different categories of AR approaches may help students learn. While AR offers new learning opportunities, it also creates new challenges for educators. We outline technological, pedagogical, learning issues related to the implementation of AR in education. For example, students in AR environments may be cognitively overloaded by the large amount of information they encounter, the multiple technological devices they are required to use, and the complex tasks they have to complete. This article provides possible solutions for some of the challenges and suggests topics and issues for future research. © 2012 Elsevier Ltd. All rights reserved. Source


Lee C.-C.,Fu Jen Catholic University | Liu C.-H.,Asia University, Taiwan | Hwang M.-S.,National Taiwan University of Science and Technology
International Journal of Network Security | Year: 2013

Password authentication is the most important and convenient protocol for verifying users to get the system's resources. Lin et al. had proposed an optimal strong-password authentication protocol (OSPA) which is a one-time password method. It can protect against the replaying attacks, impersonation attacks, and denial of service attacks. However, the authors shall show that the OSPA protocol is vulnerable to the guessing attacks in this paper. Source


Lin J.-W.,Chien Hsin University | Lai Y.-C.,National Taiwan University of Science and Technology
Computers and Education | Year: 2013

Social network awareness (SNA) has been used extensively as one of the strategies to increase knowledge sharing and collaboration opportunities. However, most SNA studies either focus on being aware of peer's knowledge context or on social context. This work proposes online formative assessments with SNA, trying to address the problems of online formative assessment (i.e. lack of individual assistances and low participant rate) and enhance learning effectiveness. This study focuses on being aware both peer's social context and knowledge context for student to promote the opportunity of peer interaction and to select the appropriate helpers to ask for help when facing problems in online assessments. Social-context information particularly includes centrality (i.e. social network position) of a candidate, and social distance (i.e. the shortest distance between the candidate and a seeker) in a sociogram, and nimbus (i.e. willingness to help others) of a candidate. A corresponding system, called Social Network Awareness for Formative Assessments (SNAFA), is further developed. The education experiments particularly focused on the effects of social-context awareness on learning activity and social activity. The results showed that the SNAFA not only increase the participant rate of students on formative assessment and opportunities of knowledge sharing, but also promote learning achievement, compared to the Traditional Formative Assessment (TFA). Meanwhile, centrality, which is represented by two indices: degree and closeness, also plays an important role in the SNAFA environment. More specifically, students with higher centrality (regardless of degree and closeness) 1) are more likely to take advantage of the social network position to ask for help, 2) easily become target helpers that peers seek to, 3) utilize the SNAFA more frequently, and 4) have better learning achievement, compared with those with lower centrality. © 2013 Elsevier Ltd. All rights reserved. Source


Tsao Y.-C.,National Taiwan University of Science and Technology
International Journal of Production Research | Year: 2016

When designing a perishable goods supply chain network under trade credit arrangements, distribution companies must contend with deteriorating inventory and product preservation efforts to maximise profits. Key decisions include locating distribution centres (DCs), assigning retail stores to DCs, joint replenishment cycle time and investing in preservation technology. This paper addresses these factors from the position that as preservation effort increases, preservation technology cost increases and deterioration rate decreases. An algorithm based on piecewise nonlinear optimisation is provided for solving supply chain network design problems efficiently. In contrast to other studies that have used the approximation approach, the proposed approach solves the original problem accurately and efficiently. Numerical studies are conducted to demonstrate the solutions procedures and determine the effects of the parameters on decisions and profits. The results of this study and the proposed modelling approach are useful references for managerial decisions in designing a supply chain network the context of trade credit and inventory deterioration. © 2016 Taylor & Francis Source


Shih Y.-P.,National Taiwan University of Science and Technology | Chen S.-D.,Luren Precision Co.
Mechanism and Machine Theory | Year: 2012

Form grinding is the most popular finishing process for large-size gear because of its high accuracy, efficiency, and flexibility in tooth flank modification. Theoretically, this tooth flank topographical modification is calculated using loaded tooth contact analysis (LTCA), which takes into account the gear tooth, shaft, and housing deflections. Such topographical modification, however, is difficult in the existing gear form grinding method. To simplify production of the ground tooth flank topography, this paper proposes a tooth flank modification grinding method with high-order correction based on the degrees of freedom in the five-axis computer numerical control (CNC) gear profile grinding machine. Each axis of the grinding machine is formulated as a high-order polynomial, and the sensitivity of the polynomial coefficient is derived based on the topographic normal deviation on the gear tooth flank. The ground tooth flank can be approximated to the theoretical tooth flank by adjusting the coefficients of the polynomials based on their sensitivity. We demonstrate the validity of this flank correction method numerically using a helical gear made by the five-axis CNC gear profile grinding machine. © 2011 Elsevier Ltd. All rights reserved. Source


Lee D.-J.,National Taiwan University | Lee D.-J.,National Taiwan University of Science and Technology | Wong B.-T.,National Taiwan University | Adav S.S.,National Taiwan University
Applied Microbiology and Biotechnology | Year: 2014

The strain NSC3T, a novel, facultative, chemolithotrophic, denitrifying, alkaliphilic, sulfide-oxidizing bacterium isolated from a hot spring in Yang-Ming Mountain, Taiwan, was Gram negative, rod shaped, and motile by single polar flagella and grew facultatively by adopting a denitrifying metabolism. The 16S rRNA sequence analysis revealed that strain NSC3T belongs to beta subclass of the Proteobacteria and most closely related to Azoarcus evansii KB740T (95.44 %), Azoarcus toluvorans Td-21T (95.21 %), Azoarcus tolulyticus Tol-4T (95.08 %), and Azoarcus toluclasticus MF63T (94.94 %). The phylogenetic analyses based on 16S rRNA gene sequences indicated that the strain NSC3T formed a distinct lineage in the Betaproteobacteria and that it exhibited the highest level of sequence similarity with species of the genera Azoarcus (95.28-93.13 %). The major fatty acids of the type strain were C16:0 (26.9 %), C16:1w7c (28.9 %), C18:0 (9.6 %), and C18:1w7c/w6c (29.9 %). The DNA G+C content of genomic DNA was 63.7 mol%. On the basis of the 16S rRNA sequence similarity, phenotypic and genotypic characteristics, and chemotaxonomic data, the strain NSC3T could be differentiated from other species of the genus Azoarcus. Therefore, strain NSC3T (equal to BCRC 80111T and DSM 24109T) is proposed as a novel species in genus Azoarcus, for which the name Azoarcus taiwanensis sp nov is proposed. The strain NSC3T is deposited in Bioresource Collection and Research Center, Taiwan, under the reference number BCRC 80111T, and German Collection of Microorganisms and Cell Cultures, Germany (DSMZ), with DSM 24109T. © 2013 Springer-Verlag Berlin Heidelberg. Source


Lin Z.-C.,National Taiwan University of Science and Technology | Wang R.-Y.,Army Academy Roc
International Journal of Advanced Manufacturing Technology | Year: 2014

The paper establishes a new theoretical model for abrasive removal depth for polishing a sapphire wafer using chemical mechanical polishing with a polishing pad that has a cross pattern. The theoretical model uses binary image pixel division to calculate the pixel polishing times. An abrasive contact model for single-pixel multiple abrasive particles, to estimate the contact force between a single abrasive particle and the wafer, is then established. When the contact force is calculated, it is possible to calculate the abrasive depth of a single abrasive particle on the surface of the sapphire wafer. Using this theoretical model, carring a numerical simulation with a slurry of the same concentration, but with different abrasive particle diameters, determines the removal volume and average abrasive removal depth at each pixel position and the surface condition of the wafer. The simulation result is also compared with experimental data, in order to verify that the new model is feasible. © 2014 Springer-Verlag London. Source


Wang F.-K.,National Taiwan University of Science and Technology
Quality and Reliability Engineering International | Year: 2016

To monitor a Weibull process with individual measurements, some methods such as power transformation, inverse erf function, and Box-Cox transformation have been used to transform the Weibull data to a normal distribution. In this study, we conduct a simulation study to compare their performances in terms of the bias and mean square errors. A practical guide is recommended. Additionally, we present the maximum exponentially weighted moving average chart based on the transformation method to monitor a Weibull process with individual measurements. We compare the average run lengths of the proposed chart and the combined individual and moving range charts under the three cases including mean changes, sigma changes, and both mean and sigma changes. It is shown that the proposed control chart outperforms the combined individual and moving range charts for all three cases. Moreover, two examples are used to illustrate the applicability of the proposed control chart. © 2016 John Wiley & Sons, Ltd. Source


Lin Y.-K.,National Taiwan University of Science and Technology
International Journal of Production Economics | Year: 2010

Reducing the transmission time for a flow network is an essential task. The quickest path problem thus arises to find a path with minimum transmission time. More specifically, the capacity of each arc in the network is assumed to be deterministic. Nevertheless, the capacity of each arc is stochastic due to failure, maintenance, etc. Such a network is named as a stochastic-flow network. Hence, the minimum transmission time is not a fixed number. We extend the quickest path problem to a system reliability problem that d units of data are required to be sent from the source to the sink under the time threshold T. The possibility to fulfill such requirements is named as the system reliability. In particular, the data can be transmitted through two disjoint minimal paths simultaneously. A simple algorithm is proposed to generate all lower boundary points for (d,T) and the system reliability can be subsequently computed in terms of such points. Moreover, the optimal pair of paths with highest system reliability can be further obtained. © 2009 Elsevier B.V. All rights reserved. Source


Lee L.-W.,De Lin Institute of Technology | Chen S.-M.,National Taiwan University of Science and Technology
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

This paper presents a new fuzzy decision making method based on likelihood-based comparison relations of hesitant fuzzy linguistic term sets. We also present a similarity measure between hesitant fuzzy linguistic term sets. The proposed method is more simple for fuzzy decision making than the method presented in [18]. It provides us with a useful way for decision making in a fuzzy environment. © 2013 Springer-Verlag. Source


Shih Y.-P.,National Taiwan University of Science and Technology
Mechanism and Machine Theory | Year: 2010

Gear flank modification is an important technique for reducing gear running noise and avoiding edge contact for spiral bevel and hypoid gears. This work proposes a novel ease-off flank modification methodology for spiral bevel and hypoid gears made by a modern Cartesian-type hypoid gear generator. The first step is to obtain the desired ease-off topography by calculating and then synthesizing the ease-off along the contact path from the predesigned transmission error and along the contact line from the predesigned bearing ratio. The second step establishes the ease-off sensitivity matrix that corresponds to the pinion head cutter and the six-axis motion parameters of a hypoid generator based on a mathematical model of a modern Cartesian hypoid generator. Finally, linear regression identifies the corrective machine settings for modifying the pinion tooth flanks so that they approximate the desired ease-off topography. We demonstrate the validity of this flank modification method using a numerical example of the Gleason Triac face-hobbed hypoid gear made by a Cartesian-type CNC machine. This proposed flank modification methodology can serve as a basis for developing a general technique of flank modification for other gear types. © 2010 Elsevier Ltd. All rights reserved. Source


Tseng A.A.,National Taiwan University of Science and Technology
Journal of Vacuum Science and Technology B:Nanotechnology and Microelectronics | Year: 2011

The recent advances of the fabrication technology using atomic force microscopes (AFMs) are reviewed with the focus on its effectiveness and flexibility in patterning three-dimensional (3D) engineering nanostructures. The specific hardware and software requirements, including manipulability, precision, and automation, for enhancing the capability, reliability and repeatability in patterning 3D nanostructures are evaluated. The recent progresses on patterning the one- and two-dimensional nanostructures, which provide the basic building blocks, are first assessed. The truly 3D nanostructures, which were fabricated by two general approaches, layer manufacturing and continuous depth (or height) variation, are then presented to illustrate the efficiency and versatility of the specific patterning technique adopted. The geometric precision and reliability of the features created as well as the patterning principle involved are also studied. Finally, for improving the productivity in patterning 3D structures, the schemes using parallel processing, speed increasing, and larger tips, are elaborated with a recommendation on the areas for future efforts in developing better AFM patterning techniques. © 2011 American Vacuum Society. Source


Hou H.-T.,National Taiwan University of Science and Technology
Computers and Education | Year: 2012

Massively multiple online role-playing games (MMORPGs) are very popular among students. Educational MMORPGs, however, are very rare, as are studies on gamers' behavioral patterns during such games. The current study is an empirical observation and analysis of the behavioral patterns of 100 gamers participating in an educational MMORPG called Talking Island ©. In our study, we recorded and summarized the gaming behaviors demonstrated by these participants over 335 days of observation from December 2009 to October 2010. We coded the recorded behaviors and conducted a frequency analysis, sequential analysis and cluster analysis to explore the behavioral distributions, behavioral-frequency transition and behavior-cluster patterns in the MMORPG. Gender differences in behavioral patterns were also compared and discussed. Based on the results, we discuss the potential and limitations of the game and provide suggestions for future research on and the development of educational MMORPGs. © 2012 Elsevier Ltd. All rights reserved. Source


Hsieh G.-C.,Chung Yuan Christian University | Hsieh H.-I.,National Chiayi University | Tsai C.-Y.,National Taiwan University of Science and Technology | Wang C.-H.,Chung Yuan Christian University
IEEE Transactions on Power Electronics | Year: 2013

This paper presents a two-phased tracking that forms a photovoltaic (PV) power-increment-aided incrementalconductance (PI-INC) maximum power point tracking (MPPT) to improve the tracking behavior of the conventional INCMPPT. The PI-INCMPPTperforms, using either variable-frequency constantduty control (VFCD) or constant-frequency variable-duty control (CFVD), with reference to a collectively called threshold-tracking zone (TTZ), beyond which a power-increment (PI) tracking along the Ppv -Vpv curve executes and within which an INC tracking along the Ipv -Vpv curve toward maximum power point (MPP) does. Delay tracking due to ambiguous conductance-increment detection in the flat portion of the left-hand side of the MPP along the Ipv -Vpv curve will not appear in the PI-INC MPPT by using the PI tracking with clear and correct power-increment detection along the Ppv -Vpv curve. In addition, the merit of INC MPPT to accurately track against the random solar insolation change still retains in the PI-INC MPPT that uses INC tracking toward MPP along the Ipv -Vpv curve when tracking in the TTZ. Modeling and analysis of two typical PV power converters with VFCD and CFVD controls are addressed for implementing the tracking of the PI-INC MPPT in design and experiment. The tracking behavior of PI-INC MPPT and the conventional INCMPPT is assessed and compared through elaborate experimental tests. © 2012 IEEE. Source


Kuo D.-H.,National Taiwan University of Science and Technology | Tsega M.,Bahir Dar University
Japanese Journal of Applied Physics | Year: 2014

Cu2Zn(Sn1-xInx)Se4 bulks with x = 0-0.6 were prepared by a liquid-phase reactive sintering method at 600 °C. Defect chemistry was studied by measuring electrical properties of In-doped CZTSe (In-CZTSe) as a function of dopant concentration. With increasing the x value from 0 to 0.6, the carrier concentration of In-CZTSe increased from 1017 to 1019cm-3 but the hole mobility greatly increased from 1.23cm2V-1 s-1 to a maximum value of 8.0 cm2V-1 s-1 then decreased to about 1.4 cm2V-1 s-1 at x = 0.6. The largely increased carrier concentration and the slightly changed lattice parameters for In-CZTSe with increasing the In content are related to the precipitated In-rich Cu 2BIIBIVSe4 compound and the types of their defects such as InSn and BCu. © 2014 The Japan Society of Applied Physics. Source


Lin F.-J.,National Central University | Hung Y.-C.,National Central University | Hwang J.-C.,National Taiwan University of Science and Technology | Tsai M.-T.,National Central University
IEEE Transactions on Power Electronics | Year: 2013

A Takagi-Sugeno-Kang type fuzzy neural network with asymmetric membership function (TSKFNN-AMF) is proposed in this study for the fault-tolerant control of a six-phase permanent-magnet synchronous motor (PMSM) drive system. First, the dynamics of the six-phase PMSM drive system is described in detail. Then, the fault detection and operating decision method is briefly introduced. Moreover, to achieve the required control performance and to maintain the stability of a six-phase PMSM drive system under faulty condition, the TSKFNN-AMF control, which combines the advantages of a Takagi-Sugeno-Kang type fuzzy logic system and an asymmetric membership function, is developed. The network structure, online learning algorithm using a delta adaptation law, and convergence analysis of the TSKFNN-AMF are described in detail. Furthermore, to enhance the control performance of the proposed intelligent fault-tolerant control, a 32-bit floating-point digital signal processor TMS320F28335 is adopted for the implementation of the proposed fault-tolerant control system. Finally, some experimental results are illustrated to show the validity of the proposed TSKFNN-AMF fault-tolerant control for the six-phase PMSM drive system. © 1986-2012 IEEE. Source


Chung K.-J.,Chung Yuan Christian University | Chung K.-J.,National Taiwan University of Science and Technology
Computers and Mathematics with Applications | Year: 2012

This paper takes the transportation cost into account to develop the new supplier-retailer inventory model under the condition that both supplier and retailer have adopted the two-level trade credit policy. Moreover, this paper presents the integrated total profit per unit time Π(n,T) of two decision variables n (the number of shipments from supplier to retailer per production run, a positive integer) and T (retailer's replenishment cycle length). The main purpose of this paper not only derives the closed-form formulations for the optimal solution ( n*, T*) of Π(n,T) but also simplifies the algorithm to determine the optimal solution described by Su et al. (2007) [36]. Finally, numerical examples are used to compare with those by Su et al. (2007) [36]. © 2012 Elsevier Ltd. All rights reserved. Source


Chung K.-J.,Chung Yuan Christian University | Chung K.-J.,National Taiwan University of Science and Technology | Cardenas-Barron L.E.,Monterrey Institute of Technology
Mathematical and Computer Modelling | Year: 2012

The basic EOQ/EPQ inventory models with backorders have been developed from different perspectives by several researchers. However, the arguments to locate and guarantee the optimal solution are not complete. This paper presents a complete and analytic solution procedure to the EOQ/EPQ inventory models with linear and fixed backorder costs to locate and ensure the optimal solutions. First, the sufficient and necessary conditions for the existences of the optimal solution are developed. Second, in the case if these conditions are not satisfied, then also the optimal solutions are identified for this situation. The final results are two lemmas and four useful theorems to obtain the optimal solutions to both inventory problems. © 2012 Elsevier Ltd. Source


Lin Y.-K.,National Taiwan University of Science and Technology
Computers and Operations Research | Year: 2012

In a single-commodity multistate flow network, the arc capacity is stochastic and thus the system capacity (i.e. the maximum flow from the source to the sink) is not a fixed number. This paper constructs a multicommodity multistate flow network with weighted capacity allocation to model a transportation system. Each arc with cost attribute has several possible capacities. The capacity weight, the consumed amount of arc capacity by per commodity, varies with the arcs and types of commodity. We define the system capacity as a demand vector d if the system fulfills at most d. The addressed problem in this work is to measure the service quality of a transportation system. We propose a performance index, the probability that the upper bound of the system capacity equals a demand vector d subject to the budget constraint. A simple algorithm based on minimal cuts is presented to generate all (d,B)-MC that are the maximal capacity vectors meeting exactly the demand d under the budget B. The proposed performance index can be subsequently evaluated in terms of such (d,B)-MC. © 2010 Elsevier Ltd. All rights reserved. Source


Gu B.,Virginia Polytechnic Institute and State University | Lin C.-Y.,National Taiwan University of Science and Technology | Chen B.F.,Virginia Polytechnic Institute and State University | Dominic J.,Virginia Polytechnic Institute and State University | Lai J.-S.,Virginia Polytechnic Institute and State University
IEEE Transactions on Power Electronics | Year: 2013

This paper presents a zero-voltage-switching (ZVS) full-bridge dc-dc converter combing resonant and pulse-width-modulation (PWM) power conversions for electric vehicle battery chargers. In the proposed converter, a half-bridge LLC resonant circuit shares the lagging leg with a phase-shift full-bridge (PSFB) dc-dc circuit to guarantee ZVS of the lagging-leg switches from zero to full load. A secondary-side hybrid-switching circuit, which is formed by the leakage inductance, output inductor of the PSFB dc-dc circuit, a small additional resonant capacitor, and two additional diodes, is integrated at the secondary side of the PSFB dc-dc circuit. With the clamp path of a hybrid-switching circuit, the voltage overshoots that arise during the turn off of the rectifier diodes are eliminated and the voltage of bridge rectifier is clamped to the minimal achievable value, which is equal to secondary-reflected input voltage of the transformer. The sum of the output voltage of LLC resonant circuit and the resonant capacitor voltage of the hybrid-switching circuit is applied between the bridge rectifier and the output inductor of the PSFB dc-dc circuit during the freewheeling phases. As a result, the primary-side circulating current of the PSFB dc-dc circuit is instantly reset to zero, achieving minimized circulating losses. The effectiveness of the proposed converter was experimentally verified using a 4-kW prototype circuit. The experimental results show 98.6 peak efficiency and high efficiency over wide load and output voltage ranges. © 1986-2012 IEEE. Source


Wang F.-K.,National Taiwan University of Science and Technology
Quality and Reliability Engineering International | Year: 2015

Two indices Cp(circular) and Cpk(circular) based on the functional method have been proposed to measure the process capability of circular profiles. However, these two indices only provide potential capability and a lower bound on the process yield, respectively. In this paper, we develop a new yield index Spk(circular) for circular profiles. This index provides an exact measure of process yield. The asymptotic normal distribution of the estimated index is derived. The statistical inferences such as hypothesis testing, confidence interval, and lower confidence interval can be easily constructed. A simulation study is conducted to assess the performance of the proposed method. The simulation results confirm that the estimates are close to the true value and the coverage rates of the confidence intervals are greater than the 95% lower limit of the stated nominal in most cases. One real data set is used to illustrate the applicability of the proposed method. Copyright © 2013 John Wiley & Sons, Ltd. Source


Tamang J.P.,Sikkim University | Watanabe K.,National Taiwan University of Science and Technology |