National Penghu University of Science and Technology

www.npu.edu.tw
Ma-kung, Taiwan

National Penghu University of Science and Technology is a public university located in Magong City, Penghu, Taiwan. It is one of the few higher education institutions located off the Taiwanese mainland. Wikipedia.


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Hsu M.-H.,National Penghu University of Science and Technology
Composite Structures | Year: 2010

The vibration responses of orthotropic plates on nonlinear elastic foundations are numerically modeled using the differential quadrature method. The differential quadrature technique is utilized to transform partial differential equations into a discrete eigenvalue problem. Numerical results and those from literature closely correspond to each other. Numerical results demonstrate that elastically restrained stiffness, plate aspect ratio and foundation stiffness significantly impact the dynamic behavior of orthotropic plates. © 2009 Elsevier Ltd. All rights reserved.


Chuang M.-L.,National Penghu University of Science and Technology
IEEE Transactions on Microwave Theory and Techniques | Year: 2010

This study presents a modified shunt-stub dual-band impedance transformer. The load impedances can be complex and unequal at two uncorrelated frequencies. The proposed transformer has two parts; each part is composed of a two-section transmission line. Similar to the single-stub matching network at a single frequency, a two-section transmission line is connected to the load and transforms the load impedances to normalized unit conductance at the two designated frequencies simultaneously. The resulting susceptances are then canceled out simultaneously by a two-section shunt stub at the two frequencies. The required nonlinear simultaneous equations are derived and solved to obtain the physical parameters of transmission lines. Rearranging the simultaneous equations to construct an objective function with only one unknown variable makes it easier to solve the equations. This approach avoids high-impedance transmission lines by choosing the characteristic impedance of each transmission line first. Return losses for various load impedances are simulated to validate the proposed structures. Good agreements between numerical and measured results validate the proposed structure. Copyright © 2010 IEEE.


Wang Y.-J.,National Penghu University of Science and Technology
Applied Soft Computing Journal | Year: 2014

In this paper, financial performance of Taiwan container shipping companies are evaluated by fuzzy multi-criteria decision-making (FMCDM). In the evaluating problem, we first apply grey relation analysis to partition financial ratios into several clusters and find representative indices from the clusters. Then the representative indices are considered as evaluation criteria on financial performance assessment of Taiwan container shipping companies, and an FMCDM method called fuzzy technique for order preference by similarity to ideal solution (fuzzy TOPSIS) is utilized to evaluate financial performance. By fuzzy TOPSIS, financial performances of container shipping companies are ranked, and thus a container shipping company can realize its finance competitive strength and weakness between container shipping companies. © 2014 Elsevier B.V.


Wang Y.-J.,National Penghu University of Science and Technology
Applied Soft Computing Journal | Year: 2014

In past, fuzzy multi-criteria decision-making (FMCDM) models desired to find an optimal alternative from numerous feasible alternatives under fuzzy environment. However, researches seldom focused on determination of criteria weights, although they were also important components for FMCDM. In fact, criteria weights can be computed through extending quality function deployment (QFD) under fuzzy environment, i.e. fuzzy quality function deployment (FQFD). By FQFD, customer demanded qualities expressing the opinions of customers and service development capabilities presenting the opinions of experts can be integrated into criteria weights for FMCDM. However, deriving criteria weights in FQFD may be complex and different to multiply two fuzzy numbers in real world. To resolve the tie, we will combine FQFD with relative preference relation on FMCDM problems. With the relative preference relation on fuzzy numbers, it is not necessary multiplying two fuzzy numbers to derive criteria weights in FQFD. Alternatively, adjusted criteria weights will substitute for original criteria weights through relative preference relation. Obviously, adjusted criteria weights are clearly determined and then utilized in FMCDM models. © 2013 Elsevier B.V. All rights reserved.


Generally, classical multi-criteria decision-making (MCDM) methods were extended to encompass uncertainty and vagueness of messages under fuzzy environment for solving decision-making problems, especially for technique for order preference by similarity to ideal solution (TOPSIS). In the fuzzy extension of TOPSIS, fuzzy numbers comparison and aggregation based on fuzzy preference relation are important issues to compute distance values between alternatives and ideal (or anti-ideal) solution or rank feasible alternatives, because lots of messages are reserved by fuzzy preference relation. However, fuzzy preference relation on pair-wise comparison is commonly too complex to calculate. To avoid the drawback, we use a relative preference relation improved from fuzzy preference relation in the fuzzy extension of TOPSIS for computing distance values between alternatives and ideal (or anti-ideal) solution, or obtaining relative closeness coefficients of alternatives. Thus the relative preference relation on fuzzy numbers will be associated with TOPSIS under fuzzy environment to develop a fuzzy multi-criteria decision-making (FMCDM) model. Through the association above, FMCDM problems can be easily solved by the model. Further, we compare the proposed model with other methods to demonstrate the model's feasibility and rationality. © 2014 Elsevier Inc. All rights reserved.


Chen J.-L.,National Penghu University of Science and Technology
Computers and Education | Year: 2011

Discerning what influences a student's acceptance of e-learning is still unclear and has not been well investigated. On the basis of the expectancy-value theory, much effort has been put into identifying the effectual factors regarding the technological expectancy of students. However, aside from technological usage, the adoption of an e-learning system still must consider learning behavior. Thus, researchers should take into consideration both technological and learning expectancies of students while investigating e-learning acceptance. Following mainstream literature on information system acceptance, this study postulates that a student's behavioral intention to accept an e-learning system is determined both by his or her technological expectancy and educational compatibility. Four primary factors, that is, performance expectancy, effort expectancy, social influence, and facilitating conditions, specified in the Unified Theory of Acceptance and Use of Technology (UTAUT) are used to reflect the technological expectancy of students. Further, educational compatibility, which refers the congruence of e-learning systems with the unique leaning expectancies of students, is integrated with the UTAUT to form a new theoretical model for e-learning acceptance. An empirical survey is conducted to examine the proposed model. A total of 626 valid samples were collected from the users of an e-learning system. The findings show that both technological expectancy and educational compatibility are important determinants of e-learning acceptance. However, educational compatibility reveals a greater total effect on e-learning acceptance than does technological expectancy. Implications and practical guidelines for both e-learning developers and practitioners are subsequently presented. © 2010 Elsevier Ltd. All rights reserved.


Liao Y.-H.,National Penghu University of Science and Technology
IEEE Transactions on Power Electronics | Year: 2014

This paper presents a novel simplified pulse width modulation (PWM) strategy for the bidirectional ac/dc single-phase converter in a microgrid system. Then, the operation mechanism of the novel simplified PWM is clearly explained. The number of switchings of the proposed simplified PWM strategy is one-fourth that of the conventional unipolar PWM and bipolar PWM. Based on the novel simplified PWM strategy, a feasible feedforward control scheme is developed to achieve better rectifier mode and inverter mode performance compared with the conventional dual-loop control scheme. The proposed simplified PWM strategy with the proposed feedforward control scheme has lower total harmonic distortion than the bipolar PWM and higher efficiency than both unipolar and bipolar PWMs. Furthermore, the proposed simplified PWM operated in the inverter mode also has larger available fundamental output voltage V AB than both the unipolar and bipolar PWMs. A prototype system is constructed and the control scheme is implemented using FPGA Spartan-3E XC3S250E. Both simulation and experimental results verify the validity of the proposed PWM strategy and control scheme. © 2013 IEEE.


Patent
National Penghu University of Science and Technology | Date: 2011-07-11

A simplified multilevel DC converter circuit structure comprises a dual input DC power supply, a power control module and an AC side low-pass filter, wherein each of the dual input DC power supply supplies half of the rated DC voltage to the power control module, and the power control module is composed of six power switches, and different switching combinations of each power switch are controlled to convert a DC voltage to an output of an AC voltage, and two of the power switches of the power control module perform a low-frequency switching twice every cycle of the output voltage, and the withstand voltage is equal to the input voltage, and the remaining power switches perform the switching by a high frequency, and the withstand voltage is only half of the input voltage, such that a multilevel voltage can be outputted, and a low harmonic AC waveform can be outputted from the AC side low-pass filter.


Patent
National Penghu University of Science and Technology | Date: 2013-01-30

A boomerang wind blade includes a blade body having a protruding front edge and a recess rear edge. Both sides of the center of the blade body are two wing parts bent at an angle. The wing shape of one wing part is round at the front edge and tapering towards the rear edge. The wing shape of the other wing part is round at the rear edge and tapering towards the front edge. The device with a boomerang wind blade has a shaft fixed to the center of the two wing parts of the blade body to rotate as the blade body is driven by wind. The device also has at least one generator coupled with the shaft to generate electrical power.


Chen J.-L.,National Penghu University of Science and Technology
Information and Management | Year: 2012

Computing the value of IT investments and clarifying how the portfolio of IT/IS resources affect a firm's performance and sustainable competitive advantage are critical issues today. We attempted to develop an effective measurement technique and use organizational theory to discover the strategic role of IT-enabled resources in the firm's competitive agenda. Based on a resource-based view of the firm, we proposed a way to evaluate the synergistic effect of such resources on the firm's capabilities, as they, influence the firms' strategic objectives and improve its financial performance. The technological, human, and organizational resources work together to generate sub-additive cost and super-additive value synergies. Operations, R&D, and marketing capabilities allow firms to implement a business strategy that reflects its customer needs. A survey was conducted to check our framework. Our findings should provide valuable decision guides for practitioners when choosing a portfolio of IT/IS resources for implementing business strategies. © 2012 Elsevier B.V.

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