Taipei, Taiwan

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.


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Patent
National Taiwan University of Science and Technology | Date: 2016-07-20

A sole cushioning module includes a contacting plate, a base plate, a connecting portion and a first spring leaf. The contacting plate abuts against a sole. The base plate and the contacting plate form a space. The connecting portion connects with the contacting plate and the base plate. The first spring leaf is located within the space. The first spring leaf connects with the base plate. The first spring leaf is curved and forms a first outer curved surface. A first region of the first outer curved surface abuts against the contacting plate. When the contacting plate moves towards the base plate, the contacting plate presses on the first outer curved surface. The first spring leaf deforms, and the first outer curved surface slides relative to the contacting plate. The first region shifts towards an end of the first spring leaf connecting with the base plate.


Patent
National Taiwan University of Science and Technology | Date: 2016-01-05

The disclosure provides a catalyst structure for electrolysis of water. The catalyst structure includes a ferric oxide support and a plurality of cobalt-containing compound catalysts. The plurality of cobalt-containing compound catalysts attach to a surface of the ferric oxide support. The disclosure also provides a method of forming a catalyst structure for electrolysis of water.


Patent
National Taiwan University of Science and Technology | Date: 2016-02-25

An adhesive composition is provided. The adhesive composition includes a solvent and a polyamic acid. The polyamic acid is represented by the following Formula I: in which A is pyrenyl, anthryl, benzo[a]pyrenyl, benzo[e]pyrenyl, naphtho[2,3-a]pyrenyl, dibenzo[a,e]pyrenyl, dibenzo[a,h]pyrenyl or naphthyl; n is 0 to 10; X is greater than 0 and less than 1.


Patent
National Taiwan University of Science and Technology | Date: 2015-11-05

A catalyst for a fuel cell and a manufacturing method thereof are provided. The manufacturing method includes the following steps. A first mixture is mixed with a solvent to form a mixture solution, wherein the first mixture includes a nitrogen-containing precursor, a sulfur-containing precursor, a non-noble metal-containing precursor, and a carbon support. The solvent in the mixture solution is removed to form a second mixture. A thermal treatment is performed on the second mixture.


Sun C.-Y.,Chang Gung University | Sun C.-Y.,Chang Gung Memorial Hospital | Chang S.-C.,National Taiwan University of Science and Technology | Wu M.-S.,Chang Gung University | Wu M.-S.,Chang Gung Memorial Hospital
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.


Hsu C.-H.,National Taiwan University of Science and Technology | Wang F.-K.,National Taiwan University of Science and Technology | Tzeng G.-H.,Kainan University | Tzeng G.-H.,National Chiao Tung University
Resources, Conservation and Recycling | Year: 2012

Environmentally conscious manufacturing and product recovery (ECMPRO) has become an obligation of manufacturers, and it has been extended to be the policy and strategy of businesses. Producing recyclable products and using recycled materials are optimal strategies for ECMPRO. Vendor selection (VS) is one of the multiple criteria decision-making (MCDM) problems in strategic supply chain management. The purpose of this article is to propose how the best selection to conduct the recycled materials can be implemented for enhancing and increasing the efficiency of using resources in the manufacturing process through recycled materials VS. Aluminum composite panel (ACP) is a global product, and ACP companies in Taiwan use recycled materials in more than 80% for their products on a quantity basis. Therefore, we selected the ACP industry of Taiwan as an empirical model to study VS and to reveal methods of improving gaps in each criterion for achieving the aspired levels of performance. We use the MCDM model combining DEMATEL-based on ANP (called DANP) with VIKOR to solve the recycled materials VS problems of multiple dimensions and criteria that are interdependent, instead of the independent assumption of an analytic hierarchy process, for mimicking the real-world scenario. © 2012 Elsevier B.V.


Tsai P.-F.,National Taiwan University of Science and Technology | Ma C.-Y.,Taipei Chengshih University of Science and Technology | Wu J.S.-B.,National Taiwan University of Science and Technology
Food Chemistry | Year: 2013

This study was to isolate the anti-leukaemic component from edible mushroom Hypsizygus marmoreus (Peck) Bigelow. Crude protein was extracted from the basidioma, and then purified with DEAE-Sepharose CL-6B ion exchange chromatography followed by Sephacryl S-300 gel filtration. A protein which exerted high growth inhibitory effect on human leukaemic U937 cells and sufficient toxicological safety on normal human white blood cells was isolated and named HM-3A. Electrophoresis showed HM-3A approximately 52 kDa in size. N-terminal analysis found the amino acid sequence ATTQWKTSAA and confirmed HM-3A a novel protein. High-performance anion-exchange column chromatography revealed HM-3A a glycoprotein with galactose as the major monosaccharide. Haemagglutination assay proved it non-lectin. We suggest that HM-3A is worth further investigation for antitumour use. © 2013 Elsevier Ltd.


Chang W.Z.,National Taiwan University of Science and Technology | Chu J.P.,National Taiwan University of Science and Technology | Wang S.F.,National Taipei University of Technology
Applied Physics Letters | Year: 2012

In addition to beneficial ∼3 orders of magnitude in the resistance ratio, the amorphous HoScO x film exhibits excellent resistive switching (RS) properties of low electrical stress, thin thickness (36 nm), and simple process without forming or annealing, making it potentially useful for nonvolatile memory applications. Obvious oxygen effects are seen: no apparent RS property is detected in the near-stoichiometric film with 57.6% at. oxygen, whereas distinct RS characteristics are observed in the oxygen-deficient (50.7 at. %) film. The RS property obtained is thought to be dominated by the high oxygen vacancy concentration, which serves as the filamentary conduction in the sample. © 2012 American Institute of Physics.


Kuo D.-H.,National Taiwan University of Science and Technology | Tsega M.,National Taiwan University of Science and Technology | Tsega M.,Bahir Dar University
Materials Research Bulletin | Year: 2014

Effects of the Cu variation in CuxZnSnSe4 (CZTSe) bulks with x = 1.4-2.2 on the morphological, structural, and electrical properties has been investigated. Dense CZTSe pellets with grains of 2-5 μm were obtained. All CZTSe pellets showed a p-type behavior with a carrier concentration of 1016-1019 cm-3. CZTSe at x = 1.8 and 2.0 has a high mobility above 25 cm2/V s and an un-favored hole concentration above 1018 cm-3. Although CZTSe at x = 1.6 has a low hole concentration of 1.5 × 1017 cm-3, its mobility is below 2 cm2/V s. The contradiction has made the CZTSe solar cell device with a low efficiency. The explanation, based upon vacancies and antisite defects, for the changes in electrical property is supported by the data from lattice parameter. The study in bulk CZTSe and its defects is helpful as they are applied to the fabrication of thin-film solar cell devices.© 2013 Elsevier Ltd. All rights reserved.


Cheng F.-C.,National Taiwan University of Science and Technology | Huang S.-C.,National Taipei University of Technology | Ruan S.-J.,National Taiwan University of Science and Technology
IEEE Transactions on Systems, Man and Cybernetics Part C: Applications and Reviews | Year: 2011

In this paper, we propose a novel background subtraction approach in order to accurately detect moving objects. Our method involves three important proposed modules: a block alarm module, a background modeling module, and an object extraction module. The block alarm module efficiently checks each block for the presence of either a moving object or background information. This is accomplished by using temporal differencing pixels of the Laplacian distribution model and allows the subsequent background modeling module to process only those blocks that were found to contain background pixels. Next, the background modeling module is employed in order to generate a high-quality adaptive background model using a unique two-stage training procedure and a novel mechanism for recognizing changes in illumination. As the final step of our process, the proposed object extraction module will compute the binary object detection mask through the applied suitable threshold value. This is accomplished by using our proposed threshold training procedure. The performance evaluation of our proposed method was analyzed by quantitative and qualitative evaluation. The overall results show that our proposed method attains a substantially higher degree of efficacy, outperforming other state-of-the-art methods by Similarity and F1 accuracy rates of up to 35.50 and 26.09, respectively. © 2010 IEEE.


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.


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.


Wang Y.-R.,St. John's 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.


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.


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.


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.


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.


Cheng K.-H.,National Chiao Tung University | Cheng K.-H.,National Taiwan University of Science and Technology | Tsai C.-C.,National Taiwan University of Science and Technology
Journal of Science Education and Technology | Year: 2013

Augmented reality (AR) is currently considered as having potential for pedagogical applications. However, in science education, research regarding AR-aided learning is in its infancy. To understand how AR could help science learning, this review paper firstly has identified two major approaches of utilizing AR technology in science education, which are named as image-based AR and location-based AR. These approaches may result in different affordances for science learning. It is then found that students' spatial ability, practical skills, and conceptual understanding are often afforded by image-based AR and location-based AR usually supports inquiry-based scientific activities. After examining what has been done in science learning with AR supports, several suggestions for future research are proposed. For example, more research is required to explore learning experience (e.g., motivation or cognitive load) and learner characteristics (e.g., spatial ability or perceived presence) involved in AR. Mixed methods of investigating learning process (e.g., a content analysis and a sequential analysis) and in-depth examination of user experience beyond usability (e.g., affective variables of esthetic pleasure or emotional fulfillment) should be considered. Combining image-based and location-based AR technology may bring new possibility for supporting science learning. Theories including mental models, spatial cognition, situated cognition, and social constructivist learning are suggested for the profitable uses of future AR research in science education. © 2012 Springer Science+Business Media, LLC.


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.


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.


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.


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.


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.


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.


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.


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.


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.


Chen J.-K.,National Taiwan University of Science and Technology | Pai P.-C.,National Taiwan University of Science and Technology | Chang J.-Y.,National Taiwan University of Science and Technology | Fan S.-K.,National Chiao Tung University
ACS Applied Materials and Interfaces | Year: 2012

In this work, we focus on the fabrication of the nanoassemblies consisting of the poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) brushes and gold nanoparticles (AuNPs). The employed process involves grafting of the PDMAEMA chains on an underlying substrate in a brush conformation followed by the immobilization of surface functionalized AuNPs by means of physical interaction (electrostatic attraction, entanglement, and hydrogen bonding). Atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and UV-vis spectroscopy have been employed to characterize the prepared PDMAEMA-AuNP nanoassemblies. Polymer brushes possessing various thicknesses have been found to suppress the nanoparticles' aggregation and, hence, facilitate the surface coverage. Furthermore, we patterned the PDMAEMA-AuNP nanoassemblies as an one-dimensional periodic relief grating (OPRG). The subwavelength structure of OPRG has the optical features including artificial refractive index, form birefringence and resonance and band gap effects. A mean refractive index of the PDMAEMA-AuNP nanoassemblies can be controlled by the filling factors of the OPRG structure, so that a desired distribution of refractive index of the polymer brushes-gold OPRG under various stimuli can be realized. The employed approach is simple and highly versatile for the modification of surfaces with a wide range of NPs. © 2012 American Chemical Society.


Kuo R.J.,National Taiwan University of Science and Technology | Wang Y.C.,RMIT University | Tien F.C.,National Taipei University of Technology
Journal of Cleaner Production | Year: 2010

In recent years, with the raising of awareness in environmental protection and sustainable development in enterprises, the green issue has become more and more critical in supply chain management. This study intends to develop a green supplier selection model which integrates artificial neural network (ANN) and two multi-attribute decision analysis (MADA) methods: data envelopment analysis (DEA) and analytic network process (ANP). It is called ANN-MADA hybrid method. ANN-MADA hybrid method considers both practicality in traditional supplier selection criteria and environmental regulations. It also overcomes traditional DEA drawbacks, limitations of data accuracy and decision-making units (DMUs) amounts constraint. The model evaluation results of an international well-known camera manufacturer indicate that the ANN-MADA hybrid method outperforms two other hybrid methods, ANN-DEA and ANP-DEA. It was also discovered that ANN-MADA has better power of discrimination and noise-insensitivity in evaluating green suppliers' performances. © 2010 Elsevier Ltd. All rights reserved.


Show K.-Y.,University Tunku Abdul Rahman | Lee D.-J.,National Taiwan University | Lee D.-J.,National Taiwan University of Science and Technology | Lee D.-J.,Xinjiang Institute of Ecology and Geography | Pan X.,Xinjiang Institute of Ecology and Geography
Biotechnology Advances | Year: 2013

Biological removal of carbon, nitrogen and sulfur is drawing increasing research interest in search for an efficient and cost-effective wastewater treatment. While extensive work on separate removal of nitrogen and sulfur is well documented, investigation on simultaneous denitrifying sulfide removal has only been reported recently. Most of the work on denitrifying sulfide removal has been focusing on bioreactor performance, loading and operating conditions. Nonetheless, underlying principles elucidating the biochemical reactions and the mechanisms of the microbial degradation are yet to be established. In addition, unstable denitrifying sulfide removal which is a major operating problem that hinders practical application of the process, is yet to be resolved. This paper provides a review on the state-of-the-art development of simultaneous biological removal of sulfur, nitrogen and carbon. Research on bioreactor operation and performance, reactor configurations, mechanisms and modeling work including the use of mass balance analysis and artificial neural networks is delineated. An in-depth discussion on the microbial community and functional consortium is also provided. Challenges and future work on simultaneous biological removal of nitrogen-sulfur-carbon are also outlined. © 2012 Elsevier Inc.


Cheng K.-H.,National Chiao Tung University | Liang J.-C.,National Taiwan University of Science and Technology | Tsai C.-C.,National Taiwan University of Science and Technology
Internet and Higher Education | Year: 2015

Although the effectiveness of online peer assessment for writing performance has been documented, some students may not perceive or attain learning benefits due to receiving certain types of feedback messages. This study therefore aims to explore the role of feedback messages in students' writing performance. The feedback messages given by 47 undergraduate students in a three-round online peer assessment review were firstly examined by a series of content analyses regarding the affective, cognitive, and metacognitive aspects of the comments. The influences of the feedback messages on the students' performance progression during the three rounds of review were then explored. The results show that cognitive feedback (e.g.,direct correction) was more helpful for the students' writing learning gains than was affective feedback (e.g., praising comments) and metacognitive feedback (e.g., reflecting comments). However, this effect on the students' performance progression decreased in the last stage of the activity. © 2015 Elsevier Inc. All rights reserved.


Yu V.F.,National Taiwan University of Science and Technology | Chi H.T.X.,National Taiwan University of Science and Technology | Shen C.-W.,National Central University
Applied Soft Computing Journal | Year: 2013

Although numerous research studies in recent years have been proposed for comparing and ranking fuzzy numbers, most of the existing approaches suffer from plenty of shortcomings. In particular, they have produced counter-intuitive ranking orders under certain cases, inconsistent ranking orders of the fuzzy numbers' images, and lack of discrimination power to rank similar and symmetric fuzzy numbers. This study's goal is to propose a new epsilon-deviation degree approach based on the left and right areas of a fuzzy number and the concept of a centroid point to overcome previous drawbacks. The proposed approach defines an epsilon-transfer coefficient to avoid illogicality when ranking fuzzy numbers with identical centroid points and develops two innovative ranking indices to consistently distinguish similar or symmetric fuzzy numbers by considering the decision maker's attitude. The advantages of the proposed method are illustrated through several numerical examples and comparisons with the existing approaches. The results demonstrate that this approach is effective for ranking generalized fuzzy numbers and overcomes the shortcomings in recent studies. © 2013 Elsevier B.V. All rights reserved.


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.


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.


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.


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.


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.


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.


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.


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.


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.


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.


Wu S.-H.,National Chiao Tung University | Chiu L.-K.,National Chiao Tung University | Lin K.-Y.,Ministry of Justice | Chang T.-H.,National Taiwan University of Science and Technology
IEEE Transactions on Wireless Communications | Year: 2013

A hybrid architecture is presented for downlink beamforming (BF) with phased antenna arrays (PAA) in indoor 60 GHz spatial division multiple access (SDMA) channels. To manage the multiple access and inter-symbol interferences (MAI/ISI) encountered in SDMA with limited feedbacks, a cost-effective time-domain hybrid BF (HBF) method is presented to exploit the directivity provided by PAA in radio frequency (RF) beam patterns and the spatial diversity offered by multiple baseband processing modules. To maintain signal qualities under unpredictable MAI/ISI in wireless multimedia streaming to which indoor 60 GHz radio mainly applies, robust beamformers are designed to maintain the signal to interference-plus-noise ratio (SINR) for each user with minimum total transmit power. The percentages in which the target SINRs can be satisfied with the proposed HBF schemes are found sensitive to uncertainties in the phase shifters of PAA. Two kinds of robust formulations are thus proposed to jointly combat the MAI, ISI and phase uncertainties. Robust beamformers with semi closed-form expressions can be obtained with a nonlinear kind of them, whose SINR satisfaction ratio can attain 80% or more by extensive simulations in an indoor two-user 60 GHz environment if RF beam patterns of the users do not highly overlap in space. © 2013 IEEE.


Wei C.-H.,National Taiwan University of Science and Technology | Cheng R.-G.,National Taiwan University of Science and Technology | Tsao S.-L.,National Chiao Tung University
IEEE Transactions on Vehicular Technology | Year: 2013

Machine-type communication (MTC) is a crucial service for next-generation cellular networks. Mass access to the network by MTC devices may result in the overload of radio access networks (RANs) and degrade the service quality of human-to-human communication. Group paging is one of the mechanisms proposed to alleviate the RAN-overload problem. This paper presents an analytical model based on a recursive contending-users estimation (RCE) method proposed in the literature to derive the performance metrics of collision probability, access success probability, average access delay, statistics of preamble transmissions, statistics of access delay, and utilization of random-access opportunities (RAOs) for group paging with various combinations of group sizes and reserved radio resources in a paging access interval. The optimal group size and required RAOs are subsequently derived based on the given target access success probability. Numerical results demonstrate that the proposed model can accurately estimate the performance of group paging. © 2013 IEEE.


Kuo R.J.,National Taiwan University of Science and Technology | Syu Y.J.,Vanguard International Semiconductor Corporation | Chen Z.-Y.,De Lin Institute of Technology | Tien F.C.,National Taipei University of Technology
Information Sciences | Year: 2012

Although the algorithms for cluster analysis are continually improving, most clustering algorithms still need to set the number of clusters. Thus, this study proposes a novel dynamic clustering approach based on particle swarm optimization (PSO) and genetic algorithm (GA) (DCPG) algorithm. The proposed DCPG algorithm can automatically cluster data by examining the data without a pre-specified number of clusters. The computational results of four benchmark data sets indicate that the DCPG algorithm has better validity and stability than the dynamic clustering approach based on binary-PSO (DCPSO) and the dynamic clustering approach based on GA (DCGA) algorithms. Furthermore, the DCPG algorithm is applied to cluster the bills of material (BOM) for the Advantech Company in Taiwan. The clustering results can be used to categorize products which share the same materials into clusters. © 2012 Elsevier Inc. All rights reserved.


Lu C.-C.,National Taipei University of Technology | Yu V.F.,National Taiwan University of Science and Technology
Computers and Industrial Engineering | Year: 2012

This study proposes an alternative to the conventional empirical analysis approach for evaluating the relative efficiency of distinct combinations of algorithmic operators and/or parameter values of genetic algorithms (GAs) on solving the pickup and delivery vehicle routing problem with soft time windows (PDVRPSTW). Our approach considers each combination as a decision-making unit (DMU) and adopts data envelopment analysis (DEA) to determine the relative and cross efficiencies of each combination of GA operators and parameter values on solving the PDVRPSTW. To demonstrate the applicability and advantage of this approach, we implemented a number of combinations of GA's three main algorithmic operators, namely selection, crossover and mutation, and employed DEA to evaluate and rank the relative efficiencies of these combinations. The numerical results show that DEA is well suited for determining the efficient combinations of GA operators. Among the combinations under consideration, the combinations using tournament selection and simple crossover are generally more efficient. The proposed approach can be adopted to evaluate the relative efficiency of other meta-heuristics, so it also contributes to the algorithm development and evaluation for solving combinatorial optimization problems from the operational research perspective. © 2012 Elsevier Ltd. All rights reserved.


Shih Y.-P.,National Taiwan University of Science and Technology | Chen S.-D.,Luren Precision Co.
Journal of Manufacturing Science and Engineering, Transactions of the ASME | Year: 2012

To reduce form grinding errors, this paper proposes a free-form flank topographic correction method based on a five-axis computer numerical control (CNC) gear profile grinding machine. This correction method is applied not only to the five-axis machine settings (during grinding) but also to the wheel profile (during wheel truing). To achieve free-form modification of the wheel profile, the wheel is formulated as B-spline curves using a curve fitting technique and then normal correction functions made up of four-degree polynomials are added into its working curves. Additionally, each axis of the grinding machine is formulated as a six-degree polynomial. Based on a sensitivity analysis of the polynomial coefficients (normal correction functions and CNC machine settings) on the ground tooth flank and the topographic flank errors, the corrections are solved using the least squares method. The ground tooth flank errors can then be efficiently reduced by slightly adjusting the wheel profile and five-axis movement according to the solved corrections. The validity of this flank correction method for helical gears is numerically demonstrated using the five-axis CNC gear profile grinding machine. © 2012 American Society of Mechanical Engineers.


Wei C.-H.,National Taiwan University of Science and Technology | Cheng R.-G.,National Taiwan University of Science and Technology | Tsao S.-L.,National Chiao Tung University
IEEE Communications Letters | Year: 2012

This paper presents a combinatorial model and approximation formulas to estimate the average number of successful and collided users for a one-shot random access in finite-user multichannel slotted ALOHA systems. The proposed model and approximation can be used to evaluate the performance of group paging for machine-type communication (MTC) in 3GPP LTE. Numerical results demonstrate the applicable range of the approximation formulas and the accuracy of the derived performance metrics. © 1997-2012 IEEE.


Wang K.-J.,National Taiwan University of Science and Technology | Lin Y.S.,National Taiwan University of Science and Technology | Yu J.C.P.,Takming University of Science and Technology
International Journal of Production Economics | Year: 2011

Many industries with multiple-echelon supply chains suffer inventory management with costly deteriorating rates changed along with the time, such as TFT-LCD panel manufacturing industry, IC manufacturing industry, and agricultural industry, to name a few. In addition, highly competitive pressures in business force firms to develop their partnership through strategic alliances. This study assumes that product deterioration is time-sensitive and develops an optimal integrated inventory policy for time-sensitive deteriorating products by taking into account a strategic alliance for a three-echelon supply chain (one producer, one distributor, and one retailer). This study empirically investigates how different deterioration rates in each echelon affect performances of individuals and integrated inventory policies. Sensitivity analysis is given to justify that the impact of changes in deterioration rates of each echelon is significant and the joint cost of the proposed integrated inventory policy is found to be much less than the individual policies. In addition, a compensation policy is applied to evaluate cost reduction and benefit losses under different individual policies. Through the proposed coordination mechanism, the timing and quantities of deliveries can be determined optimally in cooperation with up-/down-stream members to achieve a minimum overall cost. Furthermore, the proposed integrated inventory policy can contribute to a significant cost reduction of such supply chains, and facilitate strategic alliance among the parties in the supply chain. © 2010 Elsevier B.V. All rights reserved.


Lu M.-T.,National Chiao Tung University | Lin S.-W.,National Taiwan University of Science and Technology | Tzeng G.-H.,National Taipei University | Tzeng G.-H.,Kainan University
Decision Support Systems | Year: 2013

The use of radio frequency identification (RFID) technology has progressed tremendously in recent years. In the healthcare industry, the decision to adopt RFID technology is a problem requiring a multi-criteria decision analysis that involves both qualitative and quantitative factors. The evaluation of this decision may be based on imprecise information or uncertain data. Furthermore, there can be significant dependence and feedbacks between the different criteria and alternatives. However, most conventional decision models cannot capture these complex interrelationships. As a result, in this study we develop a general evaluation framework for industry evaluation, improvement and adoption of RFID. We use a hybrid Multiple Criteria Decision Making (MCDM) method known as DDANPV that combines DEMATEL (decision making trial and evaluation laboratory), DANP (DEMATEL-based ANP), and VIKOR to evaluate the factors that influence the adoption of RFID. Specifically, we study the adoption of RFID in Taiwan's healthcare industry. We find that technology integration is the most influential criterion and the strongest driver in the adoption of RFID of Taiwan's healthcare industry. © 2013 Elsevier B.V.


Grant
Agency: Cordis | Branch: FP7 | Program: CP-IP | Phase: EeB.NMP.2011-3;EeB-NMP.2011-1 | Award Amount: 7.13M | Year: 2012

The project aims at developing new technology routes to integrate waste materials in the production cycle of concrete, for both ready-mixed and pre-cast applications, resulting in an innovative light-weight, eco-compatible and cost-effective construction material, made by all-waste raw materials and characterized by low embodied energy and CO2 and by improved ductility and thermal insulation performances. The target of low embodied energy and CO2 will be mainly achieved through working on the binders side, while the target of energy efficiency (heat insulation) will be mainly achieved through working on the aggregates side. The use of lightweight recycled aggregates will allow making the target material lightweight and heat-insulating. The focus will be on waste materials that, for quantity, distribution and characteristics are also a social problem but, on the other hand, are available in quantities enough for feeding the concrete industry. On the binder side the aim is the complete replacement of cement by waste materials of high silicon dioxide content, e.g., municipal incinerator ash, ash disposed from coal-fired thermal power plants, and/or in combination with by-products such as ferronickel slag and natural or man-made pozzolans like -silica and metakaolin. Properties regulators will be studied, consisting of highly active products that will regulate the performance of the binder, taking into account the waste raw materials variability, in order to achieve and stabilize the required properties of final products. The innovative solutions set-up at material level will then be employed to develop innovative concepts of modular building components. The project results, while setting-up a novel low-cost material for producing energy-efficient buildings components, will also contribute to solving the issue of waste pressure on towns and to reducing the consumption of not-renewable natural raw materials.


Cheng F.-C.,National Taiwan University of Science and Technology | Huang S.-C.,National Taipei University of Technology | Ruan S.-J.,National Taiwan University of Science and Technology
IEEE Transactions on Broadcasting | Year: 2011

Background subtraction involves generating the background model from the video sequence to detect the foreground and object for many computer vision applications, including traffic security, human-machine interaction, object recognition, and so on. In general, many background subtraction approaches cannot update the current status of the background image in scenes with sudden illumination change. This is especially true in regard to motion detection when light is suddenly switched on or off. This paper proposes an illumination-sensitive background modeling approach to analyze the illumination change and detect moving objects. For the sudden illumination change, an illumination evaluation is used to determine two background candidates, including a light background image and a dark background image. Based on the background model and illumination evaluation, the binary mask of moving objects can be generated by the proposed thresholding function. Experimental results demonstrate the effectiveness of the proposed approach in providing a promising detection outcome and low computational cost. © 2011 IEEE.


Grant
Agency: Cordis | Branch: FP7 | Program: CP-IP | Phase: EeB.NMP.2013-6 | Award Amount: 5.93M | Year: 2013

EcoShopping project aims to build a holistic retrofitting solution for commercial buildings to reduce primary energy consumption down to less than 80kWh/m2 per year and increase the share of RES (Renewable Energy Sources) more than 50% compared to the state of the art. The approach will be systemic by developing (1). Novel thermal insulation solutions using cost effective materials to further reduce the thermal losses and lower the energy consumption. (2). Easy to install and cascadable daylighting technologies based on the NLIS system to reduce energy billing and improve comfort. (3). HVAC Retrofitting systemic approach based on RES direct powered DC variable speed heat pump and harnessing the Building Thermal Mass for reducing the energy consumption. (4). Integrated solution way based on the Intelligent Automation Unit (IAU) concept and Mobile Robot. The project intends to use and integrate available products and technologies along with a network of low-cost equipment to accurately monitor the environmental and occupancy parameters to have a better control of the BAM and full exploitation of the Building Thermal Mass, which serves as a Thermal Battery and stores the RES directly without using battery, tank or other expensive storage material and simplifying the system structure. The purpose is to reduce the energy consumption without losing comfort for users and providing, at the same time, higher energy performance, security and healthy, automatic and reliable services to visitors, building operators and owners. For this the development of the IAU and the extension of Mobile Robot plays an important role, in concept of accurate control, demand reduction, user oriented and friendly service, building security etc.


Chu H.-C.,Soochow University of Taiwan | Hwang G.-J.,National Taiwan University of Science and Technology | Tsai C.-C.,National Taiwan University of Science and Technology | Tseng J.C.R.,Chung Hua University
Computers and Education | Year: 2010

The advancement of wireless and mobile technologies has enabled students to learn in an environment that combines learning resources from both the real world and the digital world. Although such an approach has been recognized as being innovative and important, several problems have been revealed in practical learning activities. One major problem is owing to the lack of proper learning strategies or tools for assisting the students to acquire knowledge in such a complex learning scenario. Students might feel excited or engaged when using the mobile devices to learn in the real context; nevertheless, their learning achievements could be disappointing. To deal with this problem, this study presents a mobile learning system that employs Radio Frequency Identification (RFID) technology to detect and examine real-world learning behaviors of students. This study also utilizes each student's responses from a two-tier test (i.e., multiple-choice questions in a two-level format) to provide personalized learning guidance (called two-tier test guiding, T 3G). The experimental results from a natural science course of an elementary school show that this innovative approach is able to improve the learning achievements of students as well as enhance their learning motivation. © 2010 Elsevier Ltd. All rights reserved.


Wu H.-Y.,National Chiayi University | Lin Y.-K.,National Taiwan University of Science and Technology | Chang C.-H.,VaNung University
Evaluation and Program Planning | Year: 2011

This study aims at developing a set of appropriate performance evaluation indices mainly based on balanced scorecard (BSC) for extension education centers in universities by utilizing multiple criteria decision making (MCDM). Through literature reviews and experts who have real practical experiences in extension education, adequate performance evaluation indices have been selected and then utilizing the decision making trial and evaluation laboratory (DEMATEL) and analytic network process (ANP), respectively, further establishes the causality between the four BSC perspectives as well as the relative weights between evaluation indices. According to this previous result, an empirical analysis of the performance evaluation of extension education centers of three universities at Taoyuan County in Taiwan is illustrated by applying VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR). From the analysis results, it indicates that "Learning and growth" is the significant influential factor and it would affect the other three perspectives. In addition, it is discovered that "Internal process" perspective as well as "Financial" perspective play important roles in the performance evaluation of extension education centers. The top three key performance indices are "After-sales service", "Turnover volume", and "Net income" The proposed evaluation model could be considered as a reference for extension education centers in universities to prioritize their improvements on the key performance indices after performing VIKOR analyses. © 2010 Elsevier Ltd.


Kuo Y.-L.,National Taiwan University of Science and Technology | Su T.-L.,St. Mary's College | Kung F.-C.,Kainan University | Wu T.-J.,National Taiwan University of Science and Technology
Journal of Hazardous Materials | Year: 2011

An optimal condition applied to the Taguchi method with an L 9 orthogonal array for preparing a visible-light driven nitrogen-modified TiO 2 (N-TiO 2) photocatalyst by a simple hydrolysis method has been examined for material characteristics and a photodecolorization test of methyl blue (MB) under various visible light source (fluorescent and blue LED lamps) irradiations. Results of the material characterization showed that the absorption of prepared N-TiO 2 powder exhibited a significant extension into visible light regimes with an optical bandgap (Eg) of around 2.96eV, which subsequently improved the visible-light photocatalytic activity of N-TiO 2 samples. The superior photocatalytic properties, the pseudo first-order reaction rate constants (k) and photodecolorization efficiency (η%) of a N-TiO 2 photocatalyst during the photodecolorization test of methyl blue (MB) under two different visible light irradiations were very evident compared to those for pure TiO 2. For photodecolorization of practical dyeing from the waste water from the dyeing and finishing industry, a higher photodecolorization efficiency of N-TiO 2 powder toward Direct blue-86 (DB-86) (Direct Fast Turquoise Blue GL) dye was also achieved. © 2011 Elsevier B.V.


Chen S.-M.,National Taiwan University of Science and Technology | Chen S.-M.,National Taichung University of Education | Chang Y.-C.,National Taiwan University of Science and Technology
IEEE Transactions on Fuzzy Systems | Year: 2011

In this paper, we propose a weighted fuzzy interpolative reasoning method for sparse fuzzy rule-based systems. It is based on a genetic algorithm (GA)-based weight-learning technique. The proposed method can deal with fuzzy rule interpolation with weighted antecedent variables. It also can deal with fuzzy rule interpolation based on polygonal membership functions and bell-shaped membership functions. We also propose a GA-based weight-learning algorithm to automatically learn the optimal weights of the antecedent variables of the fuzzy rules. Furthermore, we apply the proposed weighted fuzzy interpolative reasoning method and the proposed GA-based weight-learning algorithm to deal with the truck backer-upper control problem, the computer activity prediction problem, multivariate regression problems, and time series prediction problems. Based on statistical analysis techniques, the experimental results show that the proposed weighted fuzzy interpolative reasoning method by the use of the optimally learned weights that were obtained by the proposed GA-based weight-learning algorithm has statistically significantly smaller error rates than the existing methods. © 2006 IEEE.


Chen S.-M.,National Taiwan University of Science and Technology | Chen S.-M.,National Taichung University of Education | Chien C.-Y.,National Taiwan University of Science and Technology
Expert Systems with Applications | Year: 2011

In this paper, we present a new method, called the genetic simulated annealing ant colony system with particle swarm optimization techniques, for solving the traveling salesman problem. We also make experiments using the 25 data sets obtained from the TSPLIB (http://comopt.ifi.uni-heidelberg.de/ software/TSPLIB95/) and compare the experimental results of the proposed method with the methods of Angeniol, Vaubois, and Texier (1988), Somhom, Modares, and Enkawa (1997), Masutti and Castro (2009) and Pasti and Castro (2006). The experimental results show that both the average solution and the percentage deviation of the average solution to the best known solution of the proposed method are better than the methods of Angeniol et al. (1988), Somhom et al. (1997), Masutti and Castro (2009) and Pasti and Castro (2006). © 2011 Elsevier Ltd. All rights reserved.


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.


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.


Chen S.-M.,National Taiwan University of Science and Technology | Cheng S.-H.,Chienkuo Technical University | Lin T.-E.,National Taiwan University of Science and Technology
Information Sciences | Year: 2015

In this paper, we present a new method for group decision making using group recommendations based on interval fuzzy preference relations and consistency matrices. First, the proposed method constructs the collective consistency matrix, the weighted collective preference relation, and the group collective preference relation. Then, it constructs a consensus relation for each expert and calculates the group consensus degree of all experts. If the group consensus degree is smaller than a predefined threshold value, then it marks the consensus values in each consensus relation which are smaller than the group consensus degree and modifies the interval fuzzy preference values corresponding to the marked consensus values. The above process is performed repeatedly, until the group consensus degree is larger than or equal to the predefined threshold value. Finally, based on the group collective preference relation, it calculates the score of each alternative for ranking the preference order of the alternatives. The proposed method can overcome the drawbacks of the existing methods for group decision making. It provides us with a useful way for group decision making using group recommendations based on interval fuzzy preference relations and consistency matrices. © 2014 Elsevier Inc.


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.


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.


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.


Kuo C.,National Taiwan University of Science and Technology | Dai J.S.,King's 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.


Tsai M.-J.,National Taiwan University of Science and Technology | Hou H.-T.,National Taiwan University of Science and Technology | Lai M.-L.,National Chiayi University | Liu W.-Y.,National Taiwan University of Science and Technology | Yang F.-Y.,National Taiwan Normal University
Computers and Education | Year: 2012

This study employed an eye-tracking technique to examine students' visual attention when solving a multiple-choice science problem. Six university students participated in a problem-solving task to predict occurrences of landslide hazards from four images representing four combinations of four factors. Participants' responses and visual attention were recorded by an eye tracker. Participants were asked to think aloud during the entire task. A 4 (options) × 4 (factors) repeated measures design, two paired t-tests and effect sizes analyses were conducted to compare the fixation duration between chosen and rejected options and between relevant and irrelevant factors. Content analyses were performed to analyze participants' responses and think aloud protocols and to examine individual's Hot Zone image. Finally, sequential analysis on fixated LookZones was further utilized to compare the scan patterns between successful and unsuccessful problem solvers. The results showed that, while solving an image-based multiple-choice science problem, students, in general, paid more attention to chosen options than rejected alternatives, and spent more time inspecting relevant factors than irrelevant ones. Additionally, successful problem solvers focused more on relevant factors, while unsuccessful problem solvers experienced difficulties in decoding the problem, in recognizing the relevant factors, and in self-regulating of concentration. Future study can be done to examine the reliability and the usability of providing adaptive instructional scaffoldings for problem solving according to students' visual attention allocations and transformations in a larger scale. Eye-tracking techniques are suggested to be used to deeply explore the cognitive process during e-learning and be applied to future online assessment systems. © 2011 Elsevier Ltd. All rights reserved.


Huang R.-H.,Fu Jen Catholic University | Yang C.-L.,Fu Jen Catholic University | Cheng W.-C.,National Taiwan University of Science and Technology
International Journal of Production Economics | Year: 2013

Recently, the companies reduce the manufacturing costs and increase capacity efficiency in the competitive environment. Therefore, to balance workstation loading, the hybrid production system is necessary, so that, the flexible job shop system is the most common production system, and there are parallel machines in each workstation. In this study, the due window and the sequential dependent setup time of jobs are considered. To satisfy the customers' requirement, and reduce the cost of the storage costs at the same time, the sum of the earliness and tardiness costs is the objective. In this study, to improve the traditional ant colony system, we developed the two pheromone ant colony optimization (2PH-ACO) to approach the flexible job shop scheduling problem. Computational results indicate that 2PH-ACO performs better than ACO in terms of sum of earliness and tardiness time. © 2012 Elsevier B.V.


Chen S.-M.,National Taiwan University of Science and Technology | Chen S.-M.,National Taichung University of Education | Lee L.-W.,National Taiwan University of Science and Technology
IEEE Transactions on Systems, Man, and Cybernetics: Systems | Year: 2012

In this paper, we present a new method for interval linguistic labels aggregation and consensus measure for autocratic decision making using group recommendations based on the proposed interval linguistic labels ordered weighted average (ILLOWA) operator and the likelihood-based comparison relations of interval linguistic labels. We propose the ILLOWA operator to aggregate interval linguistic labels. We propose the concepts of likelihood-based comparison relations of interval linguistic labels. Based on the proposed ILLOWA operator and likelihood-based comparison relations of interval linguistic labels, we propose a new method for interval linguistic labels aggregation and consensus measure for autocratic decision making using group recommendations. The proposed method can overcome the drawbacks of Ben-Arieh and Chen's method. It provides us with a useful way for interval linguistic labels aggregation and consensus measure for autocratic decision making using group recommendations. © 2006 IEEE.


Grant
Agency: Cordis | Branch: H2020 | Program: RIA | Phase: EEB-04-2016 | Award Amount: 5.12M | Year: 2016

The overall goal of the RE4-Project is to promote new technological solutions for the design and development of structural and non-structural pre-fabricated elements with high degree of recycled materials and reused structures from partial or total demolition of buildings. The developed technology will aim at energy efficient new construction and refurbishment, thus minimizing environmental impacts. The RE4-Project targets the demonstration of suitable design concepts and building elements produced from CDW in an industrial environment, considering perspective issues for the market uptake of the developed solutions. The technical activities will be supported by LCA and LCC analyses, certification and standardization procedures, demonstration activities, professional training, dissemination, commercialisation and exploitation strategy definition, business modelling and business plans. The overarching purpose is to develop a RE4-prefabricated energy-efficient building concept that can be easily assembled and disassembled for future reuse, containing up to 65% in weight of recycled materials from CDW (ranging from 50% for the medium replacement of the mineral fraction, up to 65% for insulating panels and concrete products with medium mineral replacement coupled with the geopolymer binder). The reusable structures will range from 15-20% for existing buildings to 80-90% for the RE4-prefabricated building concept.


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.


Han Y.S.,National Taiwan University of Science and Technology | Zheng R.,University of Houston | Mow W.H.,Hong Kong University of Science and Technology
Proceedings - IEEE INFOCOM | Year: 2012

Due to the use of commodity software and hardware, crash-stop and Byzantine failures are likely to be more prevalent in today's large-scale distributed storage systems. Regenerating codes have been shown to be a more efficient way to disperse information across multiple nodes and recover crash-stop failures in the literature. In this paper, we present the design of regeneration codes in conjunction with integrity check that allows exact regeneration of failed nodes and data reconstruction in the presence of Byzantine failures. A progressive decoding mechanism is incorporated in both procedures to leverage computation performed thus far. The fault tolerance and security properties of the schemes are also analyzed. © 2012 IEEE.


Liu Y.-H.,National Taiwan University of Science and Technology | Hsieh C.-H.,National Taiwan University of Science and Technology | Hsieh C.-H.,TPV Technology Ltd. | Luo Y.-F.,Industrial Technology Research Institute of Taiwan
IEEE Transactions on Energy Conversion | Year: 2011

Lithium-ion (Li-ion) batteries have emerged as the major power source for todays electronic products because they can offer advantages such as high energy density, low maintenance requirement, high open-circuit voltage, low self-discharge rate, and lack of memory effect. The performance and lifespan of Li-ion batteries are closely related to the quality of the charging pattern. Therefore, an optimal charging pattern is essential for Li-ion batteries to achieve shorter charging time and longer cycle life. In this paper, a Taguchi-based algorithm is presented. Consecutive orthogonal array techniques are utilized to determine the optimal charging pattern for the five-step constant current charging method. The problem formulation, implementation procedure, and parameter setting method are described and explained in detail. Experimental results show that the obtained charging pattern is capable of charging the Li-ion batteries to 95 capacity. Comparing to the conventional constant currentconstant voltage method, the benefits of the obtained pattern are faster and safer charging and longer battery cycle life. © 2011 IEEE.


Lee D.-J.,Fudan University | Lee D.-J.,National Taiwan University of Science and Technology | Show K.-Y.,University Tunku Abdul Rahman | Su A.,Yuan Ze University
Bioresource Technology | Year: 2011

Biohydrogen is regarded as an attractive future clean energy carrier due to its high energy content and environmental-friendly conversion. While biohydrogen production is still in the early stage of development, there have been a variety of laboratory- and pilot-scale systems developed with promising potential. This work presents a review of literature reports on the pure hydrogen-producers under anaerobic environment. Challenges and perspective of biohydrogen production with pure cultures are also outlined. © 2011 Elsevier Ltd.


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

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


Show K.-Y.,University Tunku Abdul Rahman | Lee D.-J.,National Taiwan University of Science and Technology | Lee D.-J.,National Taiwan University | Chang J.-S.,National Cheng Kung University
Bioresource Technology | Year: 2013

Biofuels are viewed as promising alternatives to conventional fossil fuels because they have the potential to eliminate major environmental problems created by fossil fuels. Among the still developing biofuel technologies, biodiesel production from algae offers a greater prospect for large-scale practical use, as algae are capable of producing much more yield than other biofuels. While research on algae-based biofuel is still in its developing stage, extensive work on laboratory- and pilot-scale algae harvesting systems with promising prospects has been reported. This paper presented a discussion of the literature review on recent advances in algae separation, harvesting and drying for biofuel production. The review and discussion focus on destabilization of algae, algae harvesting technologies and algae drying processes. Challenges and prospects of algae harvesting are also outlined. © 2012 Elsevier Ltd.


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.


Hwang C.-L.,National Taiwan University of Science and Technology | Bui L.A.-T.,National Taiwan University of Science and Technology | Lin K.-L.,National Ilan University | Lo C.-T.,National Taiwan University of Science and Technology
Cement and Concrete Composites | Year: 2012

Reservoir sediment, as the main material, was blended with municipal solid waste incinerator (MSWI) fly ash (including cyclone ash and scrubber ash) to manufacture lightweight aggregates (LWAs) using a pelletizing disk, and then sintering in a rotary kiln. The selected LWA was used as coarse aggregate for producing self-consolidating lightweight concrete (SCLWC). The results show that the maximum content of MSWI fly ash should be less than 30%. LWA with specific gravity in the range of 0.88-1.69 g/cm 3 and crushing strength as high as 13.43 MPa can be produced. SCLWCs showed excellent flow-ability without bleeding or segregation. The 28-day compressive strengths of the SCLWCs ranged between 25 and 55 MPa. The electrical resistivity and ultrasonic pulse velocity of the SCLWCs satisfied the required values of 8.5 kΩ cm and 3600 m/s, respectively. Therefore, the SCLWCs produced in this study have good corrosion resistance and can be classified as good quality. © 2012 Elsevier Ltd. All rights reserved.


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.


Siriviriyanun A.,National Taiwan University of Science and Technology | Imae T.,National Taiwan University of Science and Technology | Nagatani N.,Okayama University of Science
Analytical Biochemistry | Year: 2013

The presented approach provides the advanced development of effective, rapid, and versatile electrochemical sensors for a small amount of analytes on potential, cheap, and disposable printed chips. The electrocatalytic activity of this biosensor revealed the feasible detection of hydrogen peroxide at low potential (∼0.09 V) and the detection of a biocontaminant inhibitor (organophosphorus pesticide) in a wide range of concentrations. This efficiency comes from the chemical immobilization of catalysts (Pt nanoparticles) and electron transfer-enlarging materials (carbon nanotubes) on an electrode. Especially, dendrimers raise the stable conjugation of enzymes (acetylcholinesterase/choline oxidase/peroxidase) as well as nanoparticles and carbon nanotubes on an electrode. © 2013 Elsevier Inc. All rights reserved.


Yeh A.-I.,National Taiwan University of Science and Technology | Huang Y.-C.,National Taiwan University of Science and Technology | Chen S.H.,National Ilan University
Carbohydrate Polymers | Year: 2010

The effect of particle size on enzymatic hydrolysis of cellulose has been investigated. The average size of microcrystalline cotton cellulose has been reduced to submicron scale by using a media mill. The milled products were further subjected to hydrolysis using cellulase. High cellulose concentration (7%) appeared to retard the size reduction and resulted in greater particles and smaller specific surface areas than those at low concentration (3%) with the same milling time. Initial rate method was employed to explore the rate of enzymatic hydrolysis of cellulose. The production rate of cellobiose was increased at least 5-folds due to the size reduction. The yield of glucose was also significantly increased depending upon the ratio of enzyme to substrate. A high glucose yield (60%) was obtained in 10-h hydrolysis when the average particle size was in submicron scale. © 2009 Elsevier Ltd. All rights reserved.


Dumcenco D.O.,National Taiwan University of Science and Technology | Kobayashi H.,Japan Advanced Institute of Science and Technology | Liu Z.,Japan Advanced Institute of Science and Technology | Huang Y.-S.,National Taiwan University of Science and Technology | Suenaga K.,Japan Advanced Institute of Science and Technology
Nature Communications | Year: 2013

The alloying behaviour of materials is a well-known problem in all kinds of compounds. Revealing the heteroatomic distributions in two-dimensional crystals is particularly critical for their practical use as nano-devices. Here we obtain statistics of the homo-and heteroatomic coordinates in single-layered Mo 1-x W x S 2 from the atomically resolved scanning transmission electron microscope images and successfully quantify the degree of alloying for the transition metal elements (Mo or W). The results reveal the random alloying of this mixed dichalcogenide system throughout the chemical compositions (x=0 to 1). Such a direct route to gain an insight into the alloying degree on individual atom basis will find broad applications in characterizing low-dimensional heterocompounds and become an important complement to the existing theoretical methods. © 2013 Macmillan Publishers Limited. All rights reserved.


Lee D.-J.,National Taiwan University of Science and Technology | Chen Y.-Y.,National Taiwan University | Show K.-Y.,University Tunku Abdul Rahman | Whiteley C.G.,Rhodes University | Tay J.-H.,Fudan University
Biotechnology Advances | Year: 2010

Aerobic granulation is drawing increasing global interest in a quest for an efficient and innovative technology in wastewater treatment. Developed less than two decades ago, extensive research work on aerobic granulation has been reported. The instability of the granule, which is one of the main problems that hinder practical application of aerobic granulation technology, is still to be resolved. This paper presents a review of the literature in aerobic granulation focusing on factors that influence granule formation, granule development and their stability in the context of sludge granulation. The review attempts to shed light on the potential of developing granules with adequate structural stability for practical applications. The possibilities and perspective of using stored granule as inoculums for rapid startup, and as microbial supplement to enhance treatment of bioreactor systems are also discussed. © 2010 Elsevier Inc.


Tsai S.-J.,University of Massachusetts Lowell | Huang R.F.,National Taiwan University of Science and Technology | Ellenbecker M.J.,University of Massachusetts Lowell
Annals of Occupational Hygiene | Year: 2010

Tsai et al. (Airborne nanoparticle exposures associated with the manual handling of nanoalumina and nanosilver in fume hoods. J Nanopart Res 2009; 11: 147-61) found that the handling of dry nanoalumina and nanosilver inside laboratory fume hoods can cause a significant release of airborne nanoparticles from the hood. Hood design affects the magnitude of release. With traditionally designed fume hoods, the airflow moves horizontally toward the hood cupboard; the turbulent airflow formed in the worker wake region interacts with the vortex in the constant-flow fume hood and this can cause nanoparticles to be carried out with the circulating airflow. Airborne particle concentrations were measured for three hood designs (constant-flow, constant-velocity, and air-curtain hoods) using manual handling of nanoalumina particles. The hood operator's airborne nanoparticle breathing zone exposure was measured over the size range from 5 nm to 20 μm. Experiments showed that the exposure magnitude for a constant-flow hood had high variability. The results for the constant-velocity hood varied by operating conditions, but were usually very low. The performance of the air-curtain hood, a new design with significantly different airflow pattern from traditional hoods, was consistent under all operating conditions and release was barely detected. Fog tests showed more intense turbulent airflow in traditional hoods and that the downward airflow from the double-layered sash to the suction slot of the air-curtain hood did not cause turbulence seen in other hoods.


Grant
Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: EeB.ENV.2011.3.1.5-1 | Award Amount: 3.59M | Year: 2011

The refurbishing to an energy efficient standard leads to tight buildings (whole envelope: windows, walls, etc.) and affects the indoor climate. In case of refurbishing the inhabitants or users are not adapted to this new situation. Therefore the air exchange rates could be lower than required if no mechanical ventilation is installed or the system performance is not optimised. Then, in trying to increase the energy performance of buildings, the indoor environment quality is often degraded due to the lack of exchange with the outdoor environment. People in Europe spend more than 90 % of their time indoors (living, working, and transportation). In more than 40 % of the enclosed spaces, people suffer from health- and comfortable related complains and illness. Already in 1984 the WHO reported an increased frequency in buildings with indoor climate problems. The complexity of the problem and the fact of building related symptom clusters were later described as Sick Building Syndrome. The main objective of the project is to develop innovative solutions for better monitoring the indoor environment quality and to investigate active and passive systems for improving it. The focus lies on cost-effective solutions to ensure a wide application of the developed systems. The project is based on three main objectives: - Development of monitoring systems (wireless and/or partly wired) to detect insufficient comfort and health parameter. It is foreseen to develop a modular version for allowing normal end users making a quick check of the indoor air quality. - Development of control systems for indoor environments which could be based on passive elements like cost effective photo catalytic materials or PCMs and active systems which control the air flow rates based on the monitoring data. - Modelling of indoor environments for the assessment and validation of monitoring data and to optimise with respect to energy efficiency the control parameters and systems.


Air-conditioning is a rapidly growing electrical end-use in EU. A/C systems reduce temperature of the ambient air while removing humidity. However such combined air conditioning/dehumidification is generally inefficient. A promising approach is represented by Hybrid Liquid Desiccant (HLD) systems, where the latent load is removed by a liquid desiccant dehumidifier, while the sensible load is removed by a conventional vapor compression air cooler. The heat required for regeneration of the liquid desiccants needs however to be provided by outer sources like natural gas or solar collectors. Furthermore almost all metal alloys are corroded by the most effective liquid desiccants. HLD systems are therefore not penetrating the market. Our goal is to develop an innovative HLD system in the range 100-200 kW, where waste heat from the condenser is used for regeneration of the desiccants. The energy demand by this process is 55% of the conventional technique. In cases of severe humid environments, like swimming pools, or kitchens, the energy savings can achieve easily levels of 65%-70%. Several innovative components have to be developed, namely: - Two multifunctional heat exchangers with high corrosion resistance for either water vapour absorption from the air flow or desiccant regeneration; - Development of a liquid-liquid heat exchanger with high corrosion resistance for desiccant regeneration process pre-heat (liquid-liquid desiccant). Based on the promising results of the FP7 Thermonano project, thermally conductive polymer nano-composites will be considered as material for these components and shaped into innovative engineered heat exchange surface. The partners foresee an initial market worth up to 180 MEuro by 2020, generating/maintaining 4000 job opportunities for skilled operators and installers. The partners expect that the intended HVAC solution will allow cumulative savings on energy bill of at least 60 MEuro with a pay-back time below 2 years in case of 50% use.


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.


Whiteley C.G.,National Taiwan University of Science and Technology | Lee D.-J.,National Taiwan University of Science and Technology | Lee D.-J.,National Taiwan University
Biotechnology Advances | Year: 2015

The ubiquitous bacterial cyclic di-guanosine monophosphate (c-di-GMP) emerges as an important messenger for the control of many bacterial cellular functions including virulence, motility, bioluminescence, cellulose biosynthesis, adhesion, secretion, community behaviour, biofilm formation and cell differentiation. The synthesis of this cyclic nucleotide arises from external stimuli on various signalling domains within the N-terminal region of a dimeric diguanylate cyclase. This initiates the condensation of two molecules of guanosine triphosphate juxtaposed to each other within the C-terminal region of the enzyme. The biofilm from pathogenic microbes is highly resistant to antimicrobial agents suggesting that diguanylate cyclase and its product - c-di-GMP - are key biomedical targets for the inhibition of biofilm development. Furthermore the formation and long-term stability of the aerobic granule, a superior biofilm for biological wastewater treatment, can be controlled by stimulation of c-di-GMP. Any modulation of the synthetic pathways for c-di-GMP is clearly advantageous in terms of medical, industrial and/or environmental bioremediation implications. This review discusses the structure and reaction of individual diguanylate cyclase enzymes with a focus on new directions in c-di-GMP research. Specific attention is made on the molecular mechanisms that control bacterial exopolysaccharide biofilm formation and aerobic granules. © 2014 Elsevier Inc.


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.


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.


Chen L.-Y.,National Taiwan University of Science and Technology | Yin Y.-T.,National Taiwan University of Science and Technology | Chen C.-H.,Protrustech Corporation Ltd | Chiou J.-W.,National Taiwan University
Journal of Physical Chemistry C | Year: 2011

In this study, ZnO nanowire arrays were prepared using a hydrothermal method. During growth, polyethyleneimine (PEI) and ammonia were added to adjust the structure and optical properties of the ZnO nanowires. Emission analysis revealed visible photoluminescence emissions from ZnO nanowires produced under various growth conditions. To correlate the relationship between visible emissions and structural defects in ZnO nanowires, we employed X-ray absorption spectroscopy (XAS) to characterize the coordination number and bond length of the ZnO nanowires. On the basis of analytical results, we determined that the red emission is attributed to interstitial zinc defects (Zni) and the yellow emission is attributed to interstitial oxygen defects (Oi). © 2011 American Chemical Society.


Chien H.-W.,National Taiwan University | Kuo W.-H.,National Taiwan University of Science and Technology | Wang M.-J.,National Taiwan University of Science and Technology | Tsai S.-W.,Chung Gang University | Tsai W.-B.,National Taiwan University
Langmuir | Year: 2012

A simple technique was developed to fabricate tunable micropatterned substrates based on mussel-inspired surface modification. Polydopamine (PDA) was developed on polydimethylsiloxane (PDMS) stamps and was easily imprinted to several substrates such as glass, silicon, gold, polystyrene, and poly(ethylene glycol) via microcontact printing. The imprinted PDA retained its unique reactivity and could modulate the chemical properties of micropatterns via secondary reactions, which was illustrated in this study. PDA patterns imprinted onto a cytophobic and nonfouling substrates were used to form patterns of cells or proteins. PDA imprints reacted with nucleophilic amines or thiols to conjugate molecules such as poly(ethylene glycol) for creating nonfouling area. Gold nanoparticles were immobilized onto PDA-stamped area. The reductive ability of PDA transformed silver ions to elemental metals as an electroless process of metallization. This facile and economic technique provides a powerful tool for development of a functional patterned substrate for various applications. © 2012 American Chemical Society.


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.


Chang L.-K.,National Taiwan University of Science and Technology | Chuang J.-Y.,National Taiwan University of Science and Technology | Nakao M.,Kumamoto University | Liu S.-T.,Chang Gung University
Nucleic Acids Research | Year: 2010

Epstein-Barr virus (EBV) expresses two transcription factors, Rta and Zta, during the immediate-early stage of the lytic cycle. The two proteins often collaborate to activate the transcription of EBV lytic genes synergistically. This study demonstrates that Rta and Zta form a complex via an intermediary protein, MCAF1, on Zta response element (ZRE) in vitro. The interaction among these three proteins in P3HR1 cells is also verified via coimmunoprecipitation, CHIP analysis and confocal microscopy. The interaction between Rta and Zta in vitro depends on the region between amino acid 562 and 816 in MCAF1. In addition, overexpressing MCAF1 enhances and introducing MCAF1 siRNA into the cells markedly reduces the level of the synergistic activation in 293T cells. Moreover, the fact that the synergistic activation depends on ZRE but not on Rta response element (RRE) originates from the fact that Rta and Zta are capable of activating the BMRF1 promoter synergistically after an RRE but not ZREs in the promoter are mutated. The binding of Rta-MCAF1-Zta complex to ZRE but not RRE also explains why Rta and Zta do not use RRE to activate transcription synergistically. Importantly, this study elucidates the mechanism underlying synergistic activation, which is important to the lytic development of EBV. © The Author(s) 2010. Published by Oxford University Press.


Shi Y.-C.,National Taiwan University of Science and Technology | Liao V.H.-C.,National Taiwan University | Pan T.-M.,National Taiwan University of Science and Technology
Free Radical Biology and Medicine | Year: 2012

Monascin is a major yellow compound from red mold dioscorea. We investigated monascin to test whether this compound acts as an antidiabetic and antioxidative stress agent in diabetic rats and Caenorhabditis elegans. The mechanisms by which monascin exerts its action in vivo were also examined. Streptozotocin (STZ)-induced diabetic rats were given monascin at 30 mg/kg/day and sacrificed after 8 weeks. Blood glucose and serum insulin, triglyceride, total cholesterol, and high-density lipoprotein and antioxidative enzymes in the pancreas of rats were measured. In addition, monascin was evaluated for stress resistance and potential associated mechanisms in C. elegans. Throughout the 8-week experimental period, significantly lowered blood glucose, serum triglyceride, and total cholesterol and higher high-density lipoprotein levels were observed in monascin-treated rats. Monascin-treated rats showed higher serum insulin level, lower reactive oxygen species production, and higher activities of glutathione peroxidase, superoxide dismutase, and catalase in the pancreas compared to diabetic control rats. In addition, monascin significantly induced the hepatic mRNA levels of FOXO3a, FOXO1, MnSOD, and catalase in STZ-induced diabetic rats. Monascin-treated C. elegans showed an increased survival rate during oxidative stress and heat stress treatments compared to untreated controls. Moreover, monascin extended the life span under high-glucose conditions and enhanced expression of small heat shock protein (sHSP-16.2), superoxide dismutase (SOD-3), and glutathione S-transferase (GST-4) in C. elegans. Finally, we showed that monascin affected the subcellular distribution of the FOXO transcription factor DAF-16, whereas it was unable to enhance oxidative stress resistance in the daf-16 deletion mutant in C. elegans. Mechanistic studies in rats and C. elegans suggest that the protective effects of monascin are mediated via regulation of the FOXO/DAF-16-dependent insulin signaling pathway by inducing the expression of stress response/antioxidant genes, thereby enhancing oxidative stress resistance. © 2011 Elsevier Inc.


Chen S.-C.,National Taiwan University of Science and Technology | Lin S.-W.,Chang Gung University | Chou S.-Y.,National Taiwan University of Science and Technology
Applied Soft Computing Journal | Year: 2011

Data-mining algorithms have been used in many classification problems. Among them, the decision tree (DT), back-propagation network (BPN), and support vector machine (SVM) are popular and can be applied to various areas. Nevertheless, different problems may require different parameter values when applying DT, BPN or SVM. If parameter values are not set well, results may turn out to be unsatisfactory. Further, a dataset may contain many features; however, not all features are beneficial for classifications. Therefore, a scatter search (SS) approach is proposed to obtain the better parameters and select the beneficial subset of features to attain better classification results. The above classification algorithms have their respective advantages and disadvantages, and suitability is influenced by the characteristics of the problem. If the algorithms can function together in a so-called ensemble, it is expected that better results can be obtained. Therefore, this study adapts ensemble to further enhance the classification accuracy rate. In order to evaluate the performance of the proposed approach, datasets in UCI (University of California, Irvine) were applied as the test problem set. The corresponding results were compared to several well-known, published approaches. The comparative study shows that the proposed approach improved the classification accuracy rate in most datasets. Thus, the proposed approach can be useful to both practitioners and researchers. © 2010 Elsevier B.V. All rights reserved.


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.


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.


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.


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.


Liu Y.-F.,National Taiwan University of Science and Technology | Guo J.-M.,National Taiwan University of Science and Technology | Lee J.-D.,Chang Gung University
IEEE Transactions on Image Processing | Year: 2011

This study proposes a method which can generate high quality inverse halftone images from halftone images. This method can be employed prior to any signal processing over a halftone image or the inverse halftoning used in JBIG2. The proposed method utilizes the least-mean-square (LMS) algorithm to establish a relationship between the current processing position and its corresponding neighboring positions in each type of halftone image, including direct binary search, error diffusion, dot diffusion, and ordered dithering. After which, a referenced region called a support region (SR) is used to extract features. The SR can be obtained by relabeling the LMS-trained filters with the order of importance. Moreover, the probability of black pixel occurrence is considered as a feature in this work. According to this feature, the probabilities of all possible grayscale values at the current processing position can be obtained by the Bayesian theorem. Consequently, the final output at this position is the grayscale value with the highest probability. Experimental results show that the proposed method offers better visual quality than that of Mese-Vaidyanathan's and Chang 's methods in terms of human-visual peak signal-to-noise ratio (HPSNR). In addition, the memory consumption is also superior to Mese-Vaidyanathan's method. © 2011 IEEE.


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.


Chiu C.-W.,National Taiwan University of Science and Technology | Hong P.-D.,National Taiwan University of Science and Technology | Lin J.-J.,National Taiwan University
Langmuir | Year: 2011

Nanohybrids of silver nanoparticles (AgNPs) supported on mica clay were synthesized by in situ reduction of silver nitrate in an aqueous solution. The required mica platelets of high aspect ratio were previously prepared by the exfoliation of mica clay stacks in a multilayered structure through an ionic exchange reaction with poly(oxypropylene)-amine-salt. The exfoliated nanoscale mica platelets (Mica) are polydispersed such that each platelet is 300-1000 nm in width and 1 nm in thickness. These platelets possess ionic charges in the form of ≡SiO-Na+ at 120 mequiv/100 g and are suitable for supporting AgNPs in the process of in situ reduction of silver nitrate. Transmission electronic microscopy revealed the formation of AgNPs with a narrow size distribution of ca. 8 nm in diameter on the rim of individual Mica platelets. However, the pristine layered Mica structure without exfoliation failed to produce a fine AgNP distribution but instead generated particles larger than 30 nm and some precipitates. Characterization by differential scanning calorimetry and field emission scanning electron microscopy revealed that the fine AgNPs on Mica platelets exhibited a low melting temperature of 110 °C. The AgNP/Mica nanohybrid not containing an organic dispersant is considered to be a "naked" silver particle. © 2011 American Chemical Society.


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.


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

Type 2 diabetes is a major health concern and a rapidly growing disease with a modern etiology, which produces significant morbidity and mortality. The optimal management of type 2 diabetes aims to control hyperglycemia, hypertension, and dyslipidemia to reduce overall risks. Diabetes and its complications usually develop as oxidative stress increases. Monascus-fermented rice, also called red mold rice or red mold dioscorea are used in China to enhance food color and flavor. Red mold-fermented products are popular health foods that are considered to have antiobesity, antifatigue, antioxidation, and cancer prevention effects. This review article describes the antidiabetic and antioxidative stress effects on humans and animals of red mold-fermented products or their secondary metabolites. © 2012 Springer-Verlag.


Ching J.,National Taiwan University | Liao H.-J.,National Taiwan University of Science and Technology | Lee J.-Y.,National Taiwan University of Science and Technology
Geotechnique | Year: 2011

This paper gives a brief introduction on the background and current status of rainfall-induced landslides along a mountain road (Route T-18) in Taiwan and presents a detailed analysis based on the Gaussian process model for predicting locations and occurrence times of future landslides using post Chi-Chi earthquake historical data. Based on inherent and man-made features of failed and not-failed slopes, locations of possible future landslides owing to rainfall along Route T-18 are predicted. Together with historical rainfall data, a rainfall fragility graph is established. The analysis results show that the Gaussian process model is effective in predicting landslide potentials and probabilities. Comparisons of the Gaussian process analysis and the discriminant function analysis are made, which show that the former outperforms the latter in many respects. The results are valuable for predicting where and when landslides would occur along Route T-18 in future heavy rainfalls.


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.


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.


Chen Y.,CAS National Center for Nanoscience and Technology | Xi J.,Tsinghua University | Dumcenco D.O.,National Taiwan University of Science and Technology | Liu Z.,Japan National Institute of Advanced Industrial Science and Technology | And 5 more authors.
ACS Nano | Year: 2013

Band gap engineering of atomically thin two-dimensional (2D) materials is the key to their applications in nanoelectronics, optoelectronics, and photonics. Here, for the first time, we demonstrate that in the 2D system, by alloying two materials with different band gaps (MoS2 and WS 2), tunable band gap can be obtained in the 2D alloys (Mo 1-xWxS2 monolayers, x = 0-1). Atomic-resolution scanning transmission electron microscopy has revealed random arrangement of Mo and W atoms in the Mo1-xWxS2 monolayer alloys. Photoluminescence characterization has shown tunable band gap emission continuously tuned from 1.82 eV (reached at x = 0.20) to 1.99 eV (reached at x = 1). Further, density functional theory calculations have been carried out to understand the composition-dependent electronic structures of Mo 1-xWxS2 monolayer alloys. © 2013 American Chemical Society.


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.


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.


Liu Y.-F.,National Taiwan University of Science and Technology | Guo J.-M.,National Taiwan University of Science and Technology | Lee J.-D.,Chang Gung University
IEEE Transactions on Image Processing | Year: 2011

Former research on inverse halftoning most focus on developing a general-purpose method for all types of halftone patterns, such as error diffusion, ordered dithering, etc., while fail to consider the natural discrepancies among various halftoning methods. To achieve optimal image quality for each halftoning method, the classification of halftone images is highly demanded. This study employed the least mean-square filter for improving the robustness of the extracted features, and employed the naive Bayes classifier to verify all the extracted features for classification. Nine of the most well-known halftoning methods were involved for testing. The experimental results demonstrated that the classification performance can achieve a 100% accuracy rate, and the number of distinguishable halftoning methods is more than that of a former method established by Chang and Yu. © 2011 IEEE.


Lin C.-K.,National Taiwan Ocean University | Liu T.-H.,National Taiwan University of Science and Technology | Yu J.-T.,National Taiwan University | Fu L.-C.,National Taiwan University | Hsiao C.-F.,National Taiwan University of Science and Technology
IEEE Transactions on Industrial Electronics | Year: 2014

A model-free predictive current control (PCC) of interior permanent-magnet synchronous motor (IPMSM) drive systems based on a current difference detection technique is proposed. The model-based PCC (MBPCC) of IPMSM requires knowledge of parameters such as resistance, q-axis inductance, and extended back EMF. This paper develops a new model-free approach that alleviates the need for excessive prior knowledge about the system and only utilizes the stator currents as well as the current differences corresponding to different switching states of the inverter. Despite the salient difference of the proposed approach, it adopts a measure similar to that in the MBPCC approach to obtain the next switching state of the inverter by minimizing a cost function. It is noteworthy that the proposed method is easy to implement due to its simplicity and free of any multiplication operation. For comparison purposes, a digital signal processor, TMS320LF2407, is used to execute the two aforementioned current control techniques. Several experimental results show that the proposed method can significantly improve the current-tracking performance. © 1982-2012 IEEE.


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.


Lin Y.-C.,National Taiwan University | Lin Y.-C.,National Taiwan University of Science and Technology | Chen Y.-C.,National Taiwan University
Materials and Design | Year: 2012

Titanium nitrides (TiNs) powder was used as a material to resist wear; it was then clad onto a Ti-6Al-4V substrate by gas tungsten arc welding (GTAW). During the cladding process, the TiN. x reinforcing phase was formed in situ within the clad layer. Since the TiN. x reinforcing phase exists within the clad layer, the hardness of the clad layer is double that of the substrate. Wear test results reveal that the wear resistance of TiN clad layer is up to ten times more resistant than the Ti-6Al-4V substrate. From the worn surface analysis, the primary wear mechanism of the Ti-6Al-4V specimen exhibited oxidation wear combined with adhesive wear, and the TiN clad layer specimen exhibited abrasive wear. This investigation also discusses the mechanism for forming the clad layer microstructure. During solidification of the clad layer, the motion of the liquid-solid interface caused the oval TiN. x phase to cluster, producing a dendritic appearance. © 2011 Elsevier Ltd.


Wu S.-H.,National Taiwan University of Science and Technology | Ou C.-Y.,National Taiwan University | Ching J.,National Taiwan University | Hsein Juang C.,Clemson University
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2012

Spatial variability of soil undrained shear strength is usually not rigorously considered in the design of basal heave for deep excavations. In this study, the slip circle method is employed to investigate how the required safety-factor against basal heave was affected by spatial variability in the context of reliability-based design. The nonstationary random field model is adopted to model spatial variability of undrained shear strength. Results show that the required safety-factor obtained with the consideration of spatial variability is much smaller than that without the consideration. Parametric studies show that the vertical scale of fluctuation has a significant influence on the required safety-factor: the longer the scale of fluctuation, the larger the required safety-factor. For target failure probabilities of 0.01 and 0.001, the corresponding required safety factors are in the ranges of 1.4-1.9 and 1.6-2.4, respectively, for the average value of vertical scale of fluctuation of 2.5 m. Design charts are provided for the ease of implementation, and an example of reliability-based design for basal stability is given for demonstration. © 2012 American Society of Civil Engineers.


Lin C.-Y.,National Taiwan University of Science and Technology | Liu Y.-C.,International Games System Co.
IEEE/ASME Transactions on Mechatronics | Year: 2012

This paper presents precision tracking control and constraint handling of mechatronic servo systems using model predictive control. The current study revisits integral model predictive control, a common technique used in industrial process applications, from a motion control perspective for step tracking and constraint handling. To improve the control performance for periodic signal tracking, this paper integrates an internal model-based repetitive control law with the model predictive controller and transforms the original problem to a quadratic programming problem to deal with the given constraints. The current study applies the aforesaid controls to a piezoactuated system, implemented at a 10-kHz sampling rate. This research analyzes and discusses the experimental results of several controller design parameters affecting the control performance. Asymptotic error tracking and constraint handling results particularly demonstrate the effectiveness and potential of the model predictive controller for the servo design of fast mechatronic systems. © 1996-2012 IEEE.


Yao C.-Y.,National Taiwan University of Science and Technology | Willson Jr. A.N.,University of California at Los Angeles
IEEE Transactions on Signal Processing | Year: 2012

This correspondence presents a method for designing linear-phase square-root (SR) FIR digital filters that alleviate the effect of receiver timing jitter. We take a newly conceived parameter, the roughness of the analog/FIR-SR filter impulse response, into account. We show that the error-performance of a system employing a matched SR filter pair, in the presence of receiver timing jitter, is more strongly related to how well the roughness parameter is minimized, than it is to the maximizing of the eye width caused by the Nyquist pulse. Design examples validate the proposition that the proposed method can lead to improved error performance of a high-order QAM communication system in the presence of receiver clock jitter. © 2011 IEEE.


Adav S.S.,National Taiwan University | Lee D.-J.,National Taiwan University of Science and Technology
Journal of the Taiwan Institute of Chemical Engineers | Year: 2011

Extracellular polymeric substances (EPS) play essential role in determining efficiencies of sludge bio-granulation processes. Extraction methods and analysis technique on EPS from phenol degrading aerobic granules were examined. High pressure size exclusion chromatography (HPSEC) and excitation-emission matrix (EEM) spectroscopy were used to characterize the EPS extracted from phenol-fed aerobic granules using both physical and chemical extraction protocols. Ultrasound followed by chemical extraction using formaldehyde or formamide with NaOH effectively extracted EPS from aerobic granules of compact interior. The chemical composition, apparent molecular weight and EEM characteristic peaks revealed diverse nature of loosely bound, tightly bound and pellet fractions of the EPS. Chromatographic fingerprints of extracted EPS were compared. © 2011.


Lee J.-D.,Chang Gung University | Chiou Y.-H.,Chang Gung University | Guo J.-M.,National Taiwan University of Science and Technology
Information Sciences | Year: 2013

Data hiding is one of the protective techniques for authentication or secret communication through a public and open channel such as the Internet. In this study, a novel lossless data hiding by embedding secret data into a Vector Quantization (VQ)-compressed image is proposed to achieve secret communication and data compression simultaneously. The correlation of neighboring blocks of a VQ-compressed image is explored. It is shown that the neighboring blocks of a VQ-compressed image normally have high mutual correlation. Thus, this scheme employs the neighboring processed compression indices to generate specific sub-codebooks required for encoding and hiding data simultaneously. Since the sizes of sub-codebooks are smaller than that of the original VQ codebook, the encoded size of each index can be significantly reduced. As a result, a great deal of extra free space can be created. Moreover, the original VQ-compressed images can be perfectly recovered after data extraction. To evaluate the effectiveness of this approach, various test images are employed in the experiments. As documented in the experimental results, it is shown that the performance of the proposed scheme is superior to the former schemes in terms of compression ratio, embedding rate, execution time, and embedding capacity. © 2012 Elsevier Inc. All rights reserved.


Patent
National Taiwan University of Science, Technology and National Taiwan University | Date: 2013-12-09

A dielectric constant measurement circuit includes a dielectric constant sensor, an oscillator controlling circuit, a waveform converting circuit, and a counting readout circuit. The oscillator controlling circuit generates an oscillation waveform according to the response of the dielectric constant sensor to a dielectric material. The waveform converting circuit converts the oscillation waveform into frequency division square waves. The counting readout circuit includes a switching counter, a switching circuit, a reference current source, and a current integrator. The reference current source charges the current integrator through the switching circuit controlled by the frequency division square waves, and the switching counter counts the number of the turned-on states of the switching circuit and stops counting the number of the turned-on states when a value of the output voltage from the current integrator reaches a value of the reference voltage, and the number of the turned-on states is related to the oscillation frequency.


Zheng S.,Sloan Kettering Cancer Center | Vuong B.Q.,Sloan Kettering Cancer Center | Vuong B.Q.,City College of New York | Vaidyanathan B.,Sloan Kettering Cancer Center | And 3 more authors.
Cell | Year: 2015

Transcription through immunoglobulin switch (S) regions is essential for class switch recombination (CSR), but no molecular function of the transcripts has been described. Likewise, recruitment of activation-induced cytidine deaminase (AID) to S regions is critical for CSR; however, the underlying mechanism has not been fully elucidated. Here, we demonstrate that intronic switch RNA acts in trans to target AID to S region DNA. AID binds directly to switch RNA through G-quadruplexes formed by the RNA molecules. Disruption of this interaction by mutation of a key residue in the putative RNA-binding domain of AID impairs recruitment of AID to S region DNA, thereby abolishing CSR. Additionally, inhibition of RNA lariat processing leads to loss of AID localization to S regions and compromises CSR; both defects can be rescued by exogenous expression of switch transcripts in a sequence-specific manner. These studies uncover an RNA-mediated mechanism of targeting AID to DNA. © 2015 Elsevier Inc.


Prahas D.,National Taiwan University of Science and Technology | Liu J.C.,National Taiwan University of Science and Technology | Ismadji S.,Widya Mandala Surabaya Catholic University | Wang M.-J.,National Taiwan University of Science and Technology
Journal of Environmental Engineering (United States) | Year: 2012

Tetramethylammonium hydroxide (TMAH) is widely used in manufacturing thin-film transistor liquid crystal displays (TFT-LCD) and semiconductors. Because of its toxicity and nitrogen content, TMAH-containing wastewater has to be properly treated before discharge. In this study, several commercial activated carbons were characterized and used for TMAH adsorption. Activated carbon with micropores showed higher adsorption capacity for TMAH. The adsorption kinetics could be represented by pseudo-second-order model, and the Langmuir model fitted the adsorption of TMAH on activated carbon under different pH adsorption well. Higher pH was favorable for TMAH adsorption, while there was no TMAH adsorption at pH 4.7±0.2. The adsorption was spontaneous and exothermic. Exhausted carbon could be easily regenerated by 0.1 N HCl, with no considerable reduction in performance even after five cycles of adsorption-desorption. It was proposed that electrostatic interaction was the main mechanism of TMAH adsorption on the activated carbon. © 2012 American Society of Civil Engineers.


Hwang G.-J.,National Taiwan University of Science and Technology | Wu P.-H.,National Taipei University of Education
International Journal of Mobile Learning and Organisation | Year: 2014

The use of mobile technologies in learning has attracted much attention from researchers and educators in the past decade. However, the impacts of mobile learning on students' learning performance are still unclear. In particular, some schoolteachers still doubt the effectiveness of using such new technologies in school settings. In this study, a survey has been conducted by reviewing the 2008-2012 publications in seven well-recognised Social Science Citation Index (SSCI) journals of technology-enhanced learning to investigate the applications and impacts of mobile technology-enhanced learning. It is found that mobile learning is promising in improving students' learning achievements, motivations and interests. In addition, from the survey, it is found that smartphones and tablet PCs have gradually become widely adopted mobile learning devices in recent years, which could affect the adoption of sensing technologies in the future. Accordingly, several open issues of mobile learning are addressed. Copyright © 2014 Inderscience Enterprises Ltd.


Chou J.-S.,National Taiwan University of Science and Technology | Lin C.,Public Construction Commission
Journal of Computing in Civil Engineering | Year: 2013

Proactively forecasting disputes in the initiation phase of public-private partnership (PPP) projects can considerably reduce the effort, time, and cost of managing potential claims. This comprehensive study compared classification models for PPP project dispute problems. Performance comparisons included four machine learners, four classification and regression trees, two multivariate statistical techniques, and combinations of techniques that have performed best according to a historical database. Experimental results indicate that an ensemble technique (i.e., SVMs+ANNs+C5.0) provides better cross-fold prediction accuracy (84.33%) compared with all other individual classification models. Notably, SVM (support vector machine) is the best single model for classifying dispute propensity in terms of overall performance measures. This study demonstrates the efficiency and effectiveness of data-mining techniques for early prediction of dispute propensity in PPP projects pertaining to public infrastructure services. The modeling results provide proactive-warning and decision-support information needed for managing potential disputes before disputes occur. © 2013 American Society of Civil Engineers.


Chen S.-M.,National Taiwan University of Science and Technology | Chang Y.-C.,National Taiwan University of Science and Technology | Pan J.-S.,Harbin Institute of Technology
IEEE Transactions on Fuzzy Systems | Year: 2013

In this paper, we present a new method for fuzzy rules interpolation for sparse fuzzy rule-based systems based on interval type-2 Gaussian fuzzy sets and genetic algorithms. First, we present a method to deal with the interpolation of fuzzy rules based on interval type-2 Gaussian fuzzy sets. We also prove that the proposed method guarantees to produce normal interval type-2 Gaussian fuzzy sets. Then, we present a method to learn optimal interval type-2 Gaussian fuzzy sets for sparse fuzzy rule-based systems based on genetic algorithms. We also apply the proposed fuzzy rules interpolation method and the proposed learning method to deal with multivariate regression problems and time series prediction problems. The experimental results show that the proposed fuzzy rules interpolation method using the optimally learned interval type-2 Gaussian fuzzy sets gets higher average accuracy rates than the existing methods. © 1993-2012 IEEE.


Yang W.-J.,National Taiwan University of Science and Technology | Chung K.-L.,National Taiwan University of Science and Technology | Mark Liao H.-Y.,Academia Sinica, Taiwan
Information Sciences | Year: 2012

A reversible data hiding algorithm which uses prediction errors in the color difference domain for mosaic images with the Bayer color filter array (CFA) is proposed. Furthermore, the proposed algorithm can be extended to deal with the digital time delay and integration (DTDI) mosaic images and Lukac and Plataniotis (LP) mosaic images. Experimental results on CFA, DTDI, and LP mosaic images demonstrate that the proposed algorithm can achieve high embedding capacity while maintaining good image quality. © 2011 Elsevier Inc. All rights reserved.


Wang J.-G.,National Taiwan University of Science and Technology | Lin C.-J.,National Chin - Yi University of Technology | Chen S.-M.,National Taiwan University of Science and Technology
Expert Systems with Applications | Year: 2010

As the high growth of population of vehicles, the traffic accidents are becoming more and more serious in recent years. Most occurrences of the car accidents results from the distraction, inattention and driving fatigue of the driver. Hence, in order to avoid the driver being in danger as much as possible. In the lane detection, in order to enhance lane boundary information and to suitable for various light conditions all day, we combine the self-clustering algorithm (SCA), fuzzy C-mean and fuzzy rules to process the spatial information and Canny algorithms to get good edge detection. In the lane departure warning, the system uses instantaneous information from the lane detection to calculate angle relations of the boundaries. The system sends a suitable warning signal to drivers, according to degree different of the departure. These experiments have been successfully evaluated on the PC platform of 3.2-GHz CPU and the average frame rate is up to 14 fps. Crown Copyright © 2009.


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.


Chern T.-S.,National Taiwan University of Science and Technology | Tseng K.-H.,National Pingtung University of Science and Technology | Tsai H.-L.,National Taiwan University of Science and Technology
Materials and Design | Year: 2011

The purpose of this study is to investigate the effects of the specific fluxes used in the tungsten inert gas (TIG) process on surface appearance, weld morphology, angular distortion, mechanical properties, and microstructures when welding 6mm thick duplex stainless steel. This study applies a novel variant of the autogenous TIG welding, using oxide powders (TiO2, MnO2, SiO2, MoO3, and Cr2O3), to grade 2205 stainless steel through a thin layer of the flux to produce a bead-on-plate joint. Experimental results indicate that using SiO2, MoO3, and Cr2O3 fluxes leads to a significant increase in the penetration capability of TIG welds. The activated TIG process can increase the joint penetration and the weld depth-to-width ratio, and tends to reduce the angular distortion of grade 2205 stainless steel weldment. The welded joint also exhibited greater mechanical strength. These results suggest that the plasma column and the anode root are a mechanism for determining the morphology of activated TIG welds. © 2010 Elsevier Ltd.


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.


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.


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.


Hu C.,Academia Sinica, Taiwan | Lin S.-Y.,National Taiwan University of Science and Technology | Chi W.-T.,Academia Sinica, Taiwan | Charng Y.-Y.,Academia Sinica, Taiwan | Charng Y.-Y.,National Taiwan University of Science and Technology
Plant Physiology | Year: 2012

The duplication and divergence of heat stress (HS) response genes might help plants adapt to varied HS conditions, but little is known on the topic. Here, we examined the evolution and function of Arabidopsis (Arabidopsis thaliana) mitochondrial GrpE (Mge) proteins. GrpE acts as a nucleotide-exchange factor in the Hsp70/DnaK chaperone machinery. Genomic data show that AtMge1 and AtMge2 arose from a recent whole-genome duplication event. Phylogenetic analysis indicated that duplication and preservation of Mges occurred independently in many plant species, which suggests a common tendency in the evolution of the genes. Intron retention contributed to the divergence of the protein structure of Mge paralogs in higher plants. In both Arabidopsis and tomato (Solanum lycopersicum), Mge1 is induced by ultraviolet B light and Mge2 is induced by heat, which suggests regulatory divergence of the genes. Consistently, AtMge2 but not AtMge1 is under the control of HsfA1, the master regulator of the HS response. Heterologous expression of AtMge2 but not AtMge1 in the temperature-sensitive Escherichia coli grpE mutant restored its growth at 43°C. Arabidopsis T-DNA knockout lines under different HS regimes revealed that Mge2 is specifically required for tolerating prolonged exposure to moderately high temperature, as compared with the need of the heat shock protein 101 and the HS-associated 32-kD protein for short-term extreme heat. Therefore, with duplication and subfunctionalization, one copy of the Arabidopsis Mge genes became specialized in a distinct type of HS. We provide direct evidence supporting the connection between gene duplication and adaptation to environmental stress. © 2011 American Society of Plant Biologists.


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.


Lin H.-W.,National Taiwan University of Science and Technology | Lin Y.-L.,National Chin - Yi University of Technology
Computers in Human Behavior | Year: 2013

Although much research in the past has pointed out that SimCity offers many learning opportunities, few have focused on how these were derived from game attributes and the personal value they offered. In this research, the means-end chain theory and ladder interview were chosen as the approach to explore the structure of SimCity's game attribute - learning effect - terminal value chain from learners' perspective. Findings from the study indicate that through attributes such as Construction of simulated city, Become the mayor, Offer incidents of simulated disasters and Table of information overview, learners were able to benefit from the learning effects of Cultivate imagination and creativity, Cultivate problem-solving ability, Strengthen sense of responsibility, Increase planning experience, Cultivate organizational thinking, Strengthen leadership decision-making and Improve control ability in their pursuit of values such as Sense of achievement, Fun and enjoyment of life, Self-fulfillment and Self-respect. The research has taken one step further to explore the differences in value hierarchies for respondents of different majors and levels of education for a discussion in management significance. The findings revealed the key points that learners focus on when playing digital educational games and provide useful guidelines for improvements and teaching strategies for digital educational game developers and educators. © 2013 Elsevier Ltd. All rights reserved.


Chung K.-J.,Chung Yuan Christian University | Chung K.-J.,National Taiwan University of Science and Technology
International Journal of Systems Science | Year: 2013

An inventory problem involves a lot of factors influencing inventory decisions. To understand it, the traditional economic production quantity (EPQ) model plays rather important role for inventory analysis. Although the traditional EPQ models are still widely used in industry, practitioners frequently question validities of assumptions of these models such that their use encounters challenges and difficulties. So, this article tries to present a new inventory model by considering two levels of trade credit, finite replenishment rate and limited storage capacity together to relax the basic assumptions of the traditional EPQ model to improve the environment of the use of it. Keeping in mind cost-minimisation strategy, four easy-to-use theorems are developed to characterise the optimal solution. Finally, the sensitivity analyses are executed to investigate the effects of the various parameters on ordering policies and the annual total relevant costs of the inventory system. © 2013 Taylor & Francis Group, LLC.


Yang M.-C.,National Taiwan University of Science and Technology | Wang Y.-C.F.,Academia Sinica, Taiwan
IEEE Transactions on Multimedia | Year: 2013

Learning-based approaches for image super-resolution (SR) have attracted the attention from researchers in the past few years. In this paper, we present a novel self-learning approach for SR. In our proposed framework, we advance support vector regression (SVR) with image sparse representation, which offers excellent generalization in modeling the relationship between images and their associated SR versions. Unlike most prior SR methods, our proposed framework does not require the collection of training low and high-resolution image data in advance, and we do not assume the reoccurrence (or self-similarity) of image patches within an image or across image scales. With theoretical supports of Bayes decision theory, we verify that our SR framework learns and selects the optimal SVR model when producing an SR image, which results in the minimum SR reconstruction error. We evaluate our method on a variety of images, and obtain very promising SR results. In most cases, our method quantitatively and qualitatively outperforms bicubic interpolation and state-of-the-art learning-based SR approaches. © 2012 IEEE.


Liao J.-J.,Institute of Business Administration | Huang K.-N.,St. John's University Taiwan | Chung K.-J.,Chung Yuan Christian University | Chung K.-J.,National Taiwan University of Science and Technology
International Journal of Production Economics | Year: 2012

This study attempts to determine economic order quantity for deteriorating items with two-storage facilities (one is an owned warehouse and the other is a rented warehouse) where trade credit is linked to order quantity. As assumed herein, payment delays depend on the quantity ordered, when the order quantity is less than that at which a payment delay is permitted, the payment for the items must be made immediately. Otherwise, the fixed trade credit period is permitted. Furthermore, if the order quantity exceeds the owned warehouse capacity, it will be necessary to rent a warehouse which results in an additional rental cost. Otherwise, renting a warehouse is unnecessary. The problem discussed in this study involves how retailers decide whether to rent an additional warehouse to hold more items and thus obtain a trade credit period. First, a deterministic inventory model is developed for deteriorating items under the above situation. Second, this study demonstrates that the total cost function per unit time is convex via a rigorous proof. Third, five theorems are developed to optimize the replenishment cycle time and the order lot-size. Finally, numerical examples are used to illustrate these theorems and sensitivity analysis of the optimal solution with respect to the parameters of the system is carried out and some important managerial insights are obtained. © 2012 Elsevier B.V. All rights reserved.


Grant
Agency: Cordis | Branch: FP7 | Program: CP-IP | Phase: EeB.NMP.2013-5 | Award Amount: 9.79M | Year: 2013

Despite recent evolutions of tools/practices in the Architecture Engineering, Construction and Facility Management have already resulted in considerable advances, some limitations remain, related to the complexity and variability of building life cycles, addressing building end user awareness and participation, lack of new business models, life cycle fragmentation, limited interoperability of the ICT supports. The main objective of HOLISTEEC is thus to design, develop, and demonstrate a BIM-based, on-the-cloud, collaborative building design software platform, featuring advanced design support for multi-criteria building optimization. This platform will account for all physical phenomena at the building-level, while also taking into account external, neighbourhood-level influences. The design of this platform will rely on actual, field feedback and related business models / processes, while enabling building design & construction practitioners to take their practices one step forward, for enhanced flexibility, effectiveness, and competitiveness. HOLISTEEC main assets are: (i) an innovative feedback /loop design workflow (ii) a multi-physical, multi-scale simulation engine; (iii) A unified data model for Building and Neighbourhood Digital Modeling (iv) a full-fledged open software infrastructure for building design tools interoperability leveraging available standards; (v) innovative and flexible user interfaces. HOLISTEEC is expected to have a direct impact at a marco level on the construction sector as a whole, through the following aspects: improved overall process efficiency, improved stakeholders collaboration and conflict resolution, lifecycle cost reduction, reduction of errors and reworks. These impacts will be quantitatively evaluated during the demonstration and validation phase of the project, where the proposed design methodology and tools will be extensively applied to four real construction projects, in parallel to standard design approaches.


Patent
Chung Yuan Christian University, National Taiwan University of Science and Technology | Date: 2013-01-17

A lithium battery, including an anode, a cathode, an electrolyte solution and a package structure. The anode includes a material having an oxygen-containing functional group. The cathode and the anode are configured separately, and a housing region is defined between the cathode and the anode. The electrolyte solution is disposed in the housing region, and the electrolyte solution includes water and an additive. The package structure covers the anode, the cathode and the electrolyte solution.


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.


Chen C.-Y.,National Cheng Kung University | Yeh K.-L.,National Cheng Kung University | Aisyah R.,National Cheng Kung University | Lee D.-J.,National Taiwan University of Science and Technology | Chang J.-S.,National Cheng Kung University
Bioresource Technology | Year: 2011

Microalgae have the ability to mitigate CO2 emission and produce oil with a high productivity, thereby having the potential for applications in producing the third-generation of biofuels. The key technologies for producing microalgal biofuels include identification of preferable culture conditions for high oil productivity, development of effective and economical microalgae cultivation systems, as well as separation and harvesting of microalgal biomass and oil. This review presents recent advances in microalgal cultivation, photobioreactor design, and harvesting technologies with a focus on microalgal oil (mainly triglycerides) production. The effects of different microalgal metabolisms (i.e., phototrophic, heterotrophic, mixotrophic, and photoheterotrophic growth), cultivation systems (emphasizing the effect of light sources), and biomass harvesting methods (chemical/physical methods) on microalgal biomass and oil production are compared and critically discussed. This review aims to provide useful information to help future development of efficient and commercially viable technology for microalgae-based biodiesel production. © 2010 Elsevier Ltd.


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.


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.


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.


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.


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.


Shih J.-L.,National University of Tainan | Chuang C.-W.,National Taiwan University of Science and Technology | Hwang G.-J.,National Taiwan University of Science and Technology
Educational Technology and Society | Year: 2010

This study presents a mobile exploration activity that guides elementary students to learn during a social science activity with digital support from mobile devices and wireless communications. The students are situated in both the real world and the virtual world to extend their learning experiences. The learning activities between the field and the digital system not only demonstrate the practices of mobile learning, which emphasizes learning that happens close to real life, but also provides digital learning content to facilitate students' field studies. To enhance the learning performance of the students, an inquiry-based mobile learning approach is employed to assist the students in constructing their own knowledge by taking cognitive load into consideration. To evaluate the effectiveness of the innovative approach, 33 fifth grade students were arranged to carry out investigations in the Peace Temple of southern Tainan with the inquiry-based mobile learning system. Through pre- and post- class questionnaires as well as observations and focus group interviews, descriptive quantitative and qualitative data were collected and analyzed. The results show significant positive results in terms of the students' learning. © International Forum of Educational Technology & Society (IFETS).


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.


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).


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).


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.


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.


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.


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.


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.


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.


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.


Tsai P.-S.,National Taiwan University of Science and Technology | Tsai C.-C.,National Taiwan University of Science and Technology | Hwang G.-J.,National University of Tainan
Internet and Higher Education | Year: 2011

This study aimed to explore the correlates among teachers' epistemological beliefs concerning Internet environments, their web search strategies and search outcomes. The sample of this study included 105 teachers from 63 grades 1 to 9 schools in Taiwan. The results show that the teachers with more advanced epistemological beliefs concerning Internet environments could utilize more sophisticated web search strategies (i.e. less irrelevant information-selecting) to filter and organize the information than those with less advanced beliefs. Also, the sophistication of epistemological beliefs was positively correlated to the search outcomes for open-ended questions. Hence, epistemological beliefs concerning Internet environments play an important role in web-based learning. © 2010 Elsevier Inc.


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.


Hwang G.-J.,National Taiwan University of Science and Technology | Chu H.-C.,Soochow University of Taiwan | Lin Y.-S.,National University of Tainan | Tsai C.-C.,National Taiwan University of Science and Technology
Computers and Education | Year: 2011

Previous studies have reported the importance and benefits of situating students in a real-world learning environment with access to digital-world resources. At the same time, researchers have indicated the need to develop learning guidance mechanisms or tools for assisting students to learn in such a complex learning scenario. In this study, a grid-based knowledge acquisition approach is proposed and a Mindtool is developed to help students organize and share knowledge for differentiating a set of learning targets based on what they have observed in the field. An experiment has been conducted in an elementary school Natural Science course for differentiating different species of butterflies. Forty-one fifth-grade students have been assigned to a control group and an experimental group to compare the effect of the conventional approach and that of the proposed approach. The experimental results show that the proposed approach not only improves students' learning achievements, but also significantly enhances their ability of identifying species in the field. © 2011 Elsevier Ltd. All rights reserved.


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.


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.


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.


Chang H.-H.,University of Taipei | Chen K.-L.,National Taiwan University of Science and Technology | Tsai Y.-P.,National Taiwan University of Science and Technology | Lee W.-J.,University of Texas at Arlington
IEEE Transactions on Industry Applications | Year: 2012

Based upon the analysis of load signatures, this paper presents a nonintrusive load monitoring (NILM) technique. With a characterizing response associated with a transient energy signature, a reliable and accurate recognition result can be obtained. In this paper, artificial neural networks, in combination with turn-on transient energy analysis, are used to improve recognition accuracy and computational speed of NILM results. To minimize the distortion phenomenon in current measurements from the hysteresis of traditional current transformer (CT) iron cores, a coreless Hall CT is adopted to accurately detect nonsinusoidal waves to improve NILM accuracy. The experimental results indicate that the incorporation of turn-on transient energy algorithm into NILM significantly improve the recognition accuracy and the computational speed. © 2011 IEEE.


Tsigie Y.A.,National Taiwan University of Science and Technology | Huynh L.H.,Can Tho University | Ahmed I.N.,National Taiwan University of Science and Technology | Ju Y.-H.,National Taiwan University of Science and Technology
Bioresource Technology | Year: 2012

The yeast Yarrowia lipolytica Po1g is one of the oleaginous microorganisms with a potential for biodiesel production. Sub-critical water (SCW) treatment has been known as an effective method for increasing the amount of extractable lipids in microorganisms. In this work, the amount of neutral lipids and fatty acid profiles in neutral lipids extracted from Y. lipolytica Po1g with and without SCW pre-treatment were investigated. The effects of temperature (125, 150 or 175 °C), amount of water (20, 30 or 40. mL/g biomass) and time (10, 20 or 30. min) showed that maximum neutral lipid (42.69%, w/w) could be achieved at 175 °C using 20. mL water for 20. min. The maximum neutral lipid from unpretreated samples was 23.21%. No difference in fatty acid profiles was observed, but long chain fatty acids were observed in higher amount in SCW pretreated samples. SCW pretreatment increased biodiesel yield twofold. © 2012 Elsevier Ltd.


Tsigie Y.A.,National Taiwan University of Science and Technology | Wang C.-Y.,National Taiwan University of Science and Technology | Truong C.-T.,Can Tho University | Ju Y.-H.,National Taiwan University of Science and Technology
Bioresource Technology | Year: 2011

This study investigated the possibility of utilizing detoxified sugarcane bagasse hydrolysate (DSCBH) as an alternative carbon source to culture Yarrowia lipolytica Po1g for microbial oil and biodiesel production. Sugarcane bagasse hydrolysis with 2.5% HCl resulted in maximum total sugar concentration (21.38g/L) in which 13.59g/L is xylose, 3.98g/L is glucose, and 2.78g/L is arabinose. Detoxification of SCBH by Ca(OH) 2 neutralization reduced the concentration of 5-hydroxymethylfurfural and furfural by 21.31% and 24.84%, respectively. Growth of Y. lipolytica Po1g in DSCBH with peptone as the nitrogen source gave maximum biomass concentration (11.42g/L) compared to NH 4NO 3 (6.49g/L). With peptone as the nitrogen source, DSCBH resulted in better biomass concentration than d-glucose (10.19g/L), d-xylose (9.89g/L) and NDSCBH (5.88g/L). The maximum lipid content, lipid yield and lipid productivity of Y. lipolytica Po1g grown in DSCBH and peptone was 58.5%, 6.68g/L and 1.76g/L-day, respectively. © 2011 Elsevier Ltd.


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.


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.


Liu Y.-H.,National Taiwan University of Science and Technology | Chen J.-H.,National Taiwan University of Science and Technology | Huang J.-W.,Industrial Technology Research Institute of Taiwan
Solar Energy | Year: 2014

Photovoltaic generation systems (PGSs) frequently experience partially shaded conditions (PSCs). Because PSC creates several peak values on the power-to-voltage characteristic curve, developing an algorithm that facilitates tracking global maximum power point (GMPP) is crucial. Therefore, this study introduced a two-stage GMPP tracking algorithm. In the first stage, this study developed the segmentation rules after performing extensive simulations on existing products. During the second stage, this study proposed a novel variable step-size perturb and observe method to increase the speed of searching for GMPP. The presented method feature advantages, such as simple structures, high tracking speeds, enhanced tracking accuracy, improved success rate, and easy integration with original PGS firmware. To verify the correctness of the proposed method, this study developed a 2. kW PGS prototype, which was used in subsequent simulations and experiments to assess method performance. © 2014 Elsevier Ltd.


Chien M.-C.,Industrial Technology Research Institute of Taiwan | Huang A.-C.,National Taiwan University of Science and Technology
Robotica | Year: 2012

To the best of our knowledge, this is the first paper focus on the adaptive impedance control of robot manipulators with consideration of joint flexibility and actuator dynamics. Controller design for this problem is difficult because each joint of the robot has to be described by a fifth-order cascade differential equation. In this paper, a backstepping-like procedure incorporating the model reference adaptive control strategy is employed to construct the impedance controller. The function approximation technique is applied to estimate time-varying uncertainties in the system dynamics. The proposed control law is free from the calculation of the tedious regressor matrix, which is a significant simplification in implementation. Closed-loop stability and boundedness of internal signals are proved by the Lyapunov-like analysis with consideration of the function approximation error. Computer simulation results are presented to demonstrate the usefulness of the proposed scheme. © Copyright Cambridge University Press 2011.


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.


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.


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.


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.


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.


Vempaty A.,Syracuse University | Han Y.S.,National Taiwan University of Science and Technology | Varshney P.K.,Syracuse University
IEEE Transactions on Information Theory | Year: 2014

In this paper, we consider the task of target localization using quantized data in wireless sensor networks. We propose a computationally efficient localization scheme by modeling it as an iterative classification problem. We design coding theory based iterative approaches for target localization where at every iteration, the fusion center (FC) solves an M-ary hypothesis testing problem and decides the region of interest for the next iteration. The coding theory based iterative approach works well even in the presence of Byzantine (malicious) sensors in the network. We further consider the effect of non-ideal channels. We suggest the use of soft-decision decoding to compensate for the loss due to the presence of fading channels between the local sensors and FC. We evaluate the performance of the proposed schemes in terms of the Byzantine fault tolerance capability and probability of detection of the target region. We also present performance bounds, which help us in designing the system. We provide asymptotic analysis of the proposed schemes and show that the schemes achieve perfect region detection irrespective of the noise variance when the number of sensors tends to infinity. Our numerical results show that the proposed schemes provide a similar performance in terms of mean square error as compared with the traditional maximum likelihood estimation but are computationally much more efficient and are resilient to errors due to Byzantines and non-ideal channels. © 2013 IEEE.


Wang W.-Y.,National Taiwan Normal University | Chen M.-C.,National Taiwan University of Science and Technology | Su S.-F.,National Taiwan University of Science and Technology
Automatica | Year: 2012

This paper proposes a novel method for identification and robust adaptive control of an anti-lock braking system with an active suspension system by using the hierarchical Takagi-Sugeno (T-S) fuzzy-neural model. The goal of a conventional ABS control system is to rapidly eliminate tracking error between the actual slip ratio and a set reference value in order to bring the vehicle to a stop in the shortest time possible. However, braking time and stopping distance can be reduced even further if the same control system also simultaneously considers the state of the active suspension system. The structure learning capability of the proposed hierarchical T-S fuzzy-neural network is exploited to reduce computational time, and the number of fuzzy rules. Thus, this proposed controller is applied to achieve integrated control over the anti-lock braking system (ABS) with the active suspension system. Our simulation results, presented at the end of this paper, show that the proposed controller is extremely effective in integrated control over the ABS and the active suspension system. © 2012 Elsevier Ltd. All rights reserved.


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.


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.


Nguyen-Duy K.,National Taiwan University of Science and Technology | Liu T.-H.,National Taiwan University of Science and Technology | Chen D.-F.,National Changhua University of Education | Hung J.Y.,Auburn University
IEEE Transactions on Industrial Electronics | Year: 2012

The matrix converter system is becoming a very promising candidate to replace the conventional two-stage ac/dc/ac converter, but system reliability remains an open issue. The most common reliability problem is that a bidirectional switch has an open-switch fault during operation. In this paper, a matrix converter driving a speed-controlled permanent-magnet synchronous motor is examined under a single open-switch fault. First, a new fault-detection method is proposed using only the motor currents. Second, a novel fault-tolerant switching strategy is presented. By treating the matrix converter as a two-stage rectifier/inverter, existing modulation techniques for the inverter stage can be reused, whereas the rectifier stage is modified by control to counteract the fault. However, the proposed techniques require no additional hardware devices or circuit modifications to the matrix converter. Experimental results show that the proposed method can maintain the motor speed with a maximum ripple of 2%a fivefold improvement over the uncompensated system. The proposed method therefore offers a very economical and effective solution for the matrix converter fault tolerance problem. © 2011 IEEE.


Young C.-M.,National Taiwan University of Science and Technology | Chu N.-Y.,National Taiwan University of Science and Technology | Chen L.-R.,National Changhua University of Education | Hsiao Y.-C.,National Changhua University of Education | Li C.-Z.,National Changhua University of Education
IEEE Transactions on Industrial Electronics | Year: 2013

In this paper, a single-phase multilevel inverter with battery balancing is proposed. The input of each individual inverter is directly connected to a battery. The combination of batteries can be controlled according to the batteries' voltages to implement the battery-balancing function. The operational principle of the proposed system is first described, and then, the design equation is derived. Experiments show that the battery-balancing discharge function is achieved. Finally, a prototype is designed and implemented to verify the feasibility and excellent performance. © 2012 IEEE.


Liu Y.-H.,National Taiwan University of Science and Technology | Liu C.-L.,National Taiwan University of Science and Technology | Huang J.-W.,Industrial Technology Research Institute of Taiwan | Chen J.-H.,National Taiwan University of Science and Technology
Solar Energy | Year: 2013

Photovoltaic (PV) generation systems (PGSs) have become an attractive option among renewable energy sources because they are clean, maintenance-free and environmental friendly. For PGSs, a simple and fast maximum power point tracking (MPPT) algorithm is essential. Although the static tracking efficiency of conventional MPPT method is usually high, it drops noticeably in case of rapidly changing irradiance conditions. In this paper, two fast and accurate digital MPPT methods for fast changing environments are proposed. By using piecewise line segments or cubic equation to approximate the maximum power point (MPP) locus, two high-speed, low-complexity MPPT techniques can be developed. To make the developed system more convenient for common PGS users, neural network (NN)-based program which can be used to calculate the parameters of the emulated MPP locus is also developed and embedded into the proposed digital MPPT system. Theoretical derivation and detailed design procedure will be provided in this paper. The advantages of the proposed system include low computation requirement, fast tracking speed and high static/dynamic tracking efficiencies. To validate the effectiveness and correctness of the proposed methods, simulation and experimental results of a 230. W PV system will also be provided. © 2012 Elsevier Ltd.


Patent
National Taiwan University of Science, Technology and Industrial Technology Research Institute of Taiwan | Date: 2014-06-10

A preparation method of an oligomer-polymer is provided. A maleimide is reacted with a barbituric acid to form a first oligomer-polymer. The first oligomer-polymer is then reacted with a phenylsiloxane oligomer to form a second oligomer-polymer. The phenylsiloxane oligomer is a compound represented by formula 1: Ph-Si(OH)_(x)O_(y )formula 1, wherein x is 0.65 to 2.82 and y is 0.09 to 1.17.


Liu S.-Y.,National Taiwan University of Science and Technology | Perng Y.-H.,National Taiwan University of Science and Technology | Ho Y.-F.,Chaoyang University of Technology
Renewable and Sustainable Energy Reviews | Year: 2013

Global warming or environmental issues in countries with effective energy applications and management of environmental resources have become key concerns. Energy is an important factor for countries to achieve sustainable development. Therefore, we need to actively seek renewable energy technology innovations, assess for optimization of resource inputs and strategize to proceed with effective energy strategic planning. Presently, international renewable energy technologies have been undergoing gradual and steady development. Taiwan is highly vulnerable in energy security, but geographic conditions for the development of solar energy applications have created a considerable advantage. However, the total installed solar energy capacity is far less than might be expected. Consequently, this study proceeds to explore the main resistance and key factors that affect renewable energy application concerning Taiwan buildings. Through the evaluation decision-making system model and expert decision-making groups giving evaluation values and feedback, the study found the main influences and key factors, and propose strategies for energy development in the future to improve the quality and quantity of renewable energy applications and competitiveness of national energy. This research, in addition to providing references to relevant environmental energy systems for deployment and technological research and development, also provides developing and underdeveloped countries access to applications of solar energy technology assessment and forecasts for the future. © 2013 Elsevier Ltd.


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.


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.


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.


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.


Chen T.-H.,National Pingtung Institute of Commerce | Tsao Y.-C.,National Taiwan University of Science and Technology
International Journal of Production Economics | Year: 2014

Most research in economic manufacturing/order quantity management assumes that all products are of perfect quality and are produced at a constant production rate. One result of this assumption is that the number of units produced in a given period is constant, which is not the case in real life. Most production systems produce items which are of perfect quality along with some that are of imperfect quality. Defective items, as well as the learning effect, affect production and inventory costs, thereby shaping the performance of the manufacturer-retailer chain. The present study uses the Nash, Stackelberg, and cooperation games to model an imperfect production system to investigate the combined effects of lot-sizing size integration, the learning effect, imperfect production, and the rework process on a manufacturer-retailer channel. This study also demonstrates the optimal properties of the proposed models, develops a search algorithm for obtaining optimal solutions, and conducts a numerical study to seek structural and quantitative insights into the structure of the proposed models. In addition it analyzes the sensitivity of the solutions in relation to the major parameters. © 2014 Elsevier B.V. All rights reserved.


Patent
KingLab Laboratory Equipment Co., Win Chiang Stainless Steel Co., National Taiwan University of Science and Technology | Date: 2014-10-03

The present invention provides an intelligent air curtain fume hood, which includes cabinet, inclined air curtain module, intelligent window control module and processing module. Feature of the present invention is that the inclined air curtain module is the use of inclined air flow field distribution generated during the operation of shelter in the work space, and with variable air volume theory in order to reduce the gas leaking chance to further achieve security and energy saving effect.


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.

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