Kai-chao Yao

Prof. Kai-chao Yao

orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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12 December 2014 in Energies
Verified
Journal Article
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Wei-Tzer HuangWei-Tzer Huang
Wei-Tzer Huang
KYKai-chao Yao
Kai-chao Yao
CWChun-Ching Wu
Chun-Ching Wu
This paper proposes a simple and efficient approach for the optimal dispatch in a medium-voltage microgrid (MG) with various types of distributed generation (DG). The fuel costs generated by these DGs are determined using quadratic and linear functions dependent on the types of DGs. Instead of using the traditional Lagrange multiplier method for power system economic dispatch, the proposed direct search method (DSM) approach is able to handle several inequality constraints without introducing any multipliers and furthermore it can solve the non-derivative problems or the fuel cost functions being much more complicated. Accordingly, the DSM is proposed for determining the optimal dispatch of MGs with various types of DG to minimize generation costs under grid-tied and autonomous operations. Results demonstrate that the proposed DSM is a highly suitable and simple approach to determining the optimal dispatch in medium-voltage MGs with various types of DG.

21 June 2024 in Mathematics
Verified
Journal Article
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KYKai-chao Yao
Kai-chao Yao
DCDyi-Cheng Chen
Dyi-Cheng Chen
CPChih-Hsuan Pan
Chih-Hsuan Pan
CLCheng-Lung Lin
Cheng-Lung Lin
In the industrial era, production equipment serves as an essential mother machine. In the global manufacturing industry, components such as laptop computers, mobile phones, and automotive parts all strive for aesthetic appearance. Taiwan’s machine tool industry plays a significant role globally. Faced with the constantly changing market environment, the development and competitive advantage of CNC machines are crucial topics for manufacturers. Domestic manufacturers of computer numerical control machines should move towards the integration of automated equipment to accommodate various advanced parts processing procedures. Smart manufacturing will become the trend of the industry in the future. This study invited experts from academia, industry, and research institutions to conduct expert interviews. Their opinions were compiled and analyzed, supplemented by fuzzy Delphi analysis to establish the development trends of various modules. The feasibility and demand of the product’s functional technology for industrial development were analyzed under three research dimensions and eight technical items. A total of 26 key sub-technical items were identified, achieving an expert consensus level of over 80. Furthermore, the importance ranking was analyzed using the fuzzy analytic hierarchy process, and the consistency tests were passed with C.I. < 0.1 and C.R. < 0.1. Finally, the obtained importance ranking of the hierarchical structure was used to predict the future development of computer numerical control machines through a technology roadmap, helping manufacturers use it as a reference model for future development trends to enhance market competitiveness.

28 March 2024 in Sustainability
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Journal Article
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HHHsi-Huang Hsieh
Hsi-Huang Hsieh
KYKai-chao Yao
Kai-chao Yao
CWChing-Hsin Wang
Ching-Hsin Wang
CCChih-Han Chen
Chih-Han Chen
SHShu-Hua Huang
Shu-Hua Huang
The use of a circular economy (CE) in a supply chain is conducive to remanufacturing. It can not only make the supply chain innovative but can also further ease resource consumption and lower pollution, thereby reducing carbon emissions. However, most current research remains focused on the concept of integrating circular economy supply chains (CESCs); few studies have carried out practical research in industry, and research addressing issues regarding the rubber recycling industry is even rarer. Therefore, this study refined the existing framework by screening out key factors that a CESC applies to remanufacturing products. This study conducted an expert questionnaire survey using the FDM to select key factors. Since the 30 respondents selected for this study are all experts in related fields, the reliability and stability of the method and results can be ensured. Meanwhile, this study adopted the fuzzy DEMATEL method to rank the importance of the five selected aspects and nineteen criteria and clarified cause-and-effect relationships between the criteria. The results show that important aspects, including “the circular business model” and “enhancing the resource value in the supply chain”, are both classified as cause groups; there are four main criteria that need to be highlighted, namely, “optimizing the production process”, “effectively tracking and recycling products”, “redesigning remanufactured rubber products”, and “improving resource efficiency”. Therefore, when related industries build CESCs to manufacture remanufactured products, these criteria need to be considered first. This study combined a CESC with remanufactured products, constructed a new framework to expand the related literature, and further analyzed the rubber industry and the underlying rubber recycling industry. Accordingly, related industries can refer to the new framework and key factors to develop production strategies for remanufactured products when implementing a CESC.

27 January 2022 in Mathematics
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Journal Article
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KYKai-chao Yao
Kai-chao Yao
Jian-yuan LaiJian-yuan Lai
Jian-yuan Lai
Wei-Tzer HuangWei-Tzer Huang
Wei-Tzer Huang
Jui-Che TuJui-Che Tu
Jui-Che Tu
In the face of an ever-changing global market, companies able to launch new products meeting consumer needs faster than their competitors may not only gain a larger market share, but also shorten the development cycle to reduce costs. However, there are currently no universal design strategies and tools for evaluating the design of consumer products. Therefore, the purpose of this study is mainly to formulate a systematic and innovative product design strategy and evaluation tool, so that designers can use them to select the key factors when designing consumer products and design products that meet customer needs in the shortest development cycle. First of all, this study was designed to sort out general design methods and influencing factors in consumer product design based on theoretical analysis and expert interviews. Next, a questionnaire survey of 15 design-related experts and scholars was conducted, and the most important design methods and design factors were selected using the Fuzzy Delphi Method (FDM). After that, the analytical network process (ANP) method was used to obtain the priority weight of each design factor, and select the optimal product design strategy, QTPCP, and the deciding elements that affect consumer demand for products, including 2 dimensions, 11 design elements, and 38 design factors, making theoretical contributions to product design management. The design strategies and evaluation tools developed according to the conclusions are helpful in comprehensive planning and design selection for products of different natures, and make practical contributions, enabling product developers or designers to efficiently select the optimal product design when faced with different new product designs.

11 February 2018 in Energies
Verified
Journal Article
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Wei-Tzer HuangWei-Tzer Huang
Wei-Tzer Huang
KYKai-chao Yao
Kai-chao Yao
MCMing-Ku Chen
Ming-Ku Chen
FWFeng-Ying Wang
Feng-Ying Wang
CZCang-Hui Zhu
Cang-Hui Zhu
YHYuan-Hsiang Ho
Yuan-Hsiang Ho
The expression and calculation of transmission loss (TL) play key roles for solving the power system economic dispatch (ED) problem. ED including TL must compute the total TL and incremental transmission loss (ITL) by executing power flow equations. However, solving the power flow equations is time-consuming and may result in divergence by the iteration procedure. This approach is unsuitable for real-time ED in practical power systems. To avoid solving nonlinear power flow equations, most power companies continue to adopt the TL formula in ED. Traditional loss formulas are composed of network parameters and in terms of the generator’s real power outputs. These formulas are derived by several assumptions, but these basic assumptions sacrifice accuracy. In this study, a new expression for the loss formula is proposed to improve the shortcomings of traditional loss formulas. The coefficients in the new loss formula can be obtained by recording the power losses according to varying real and reactive power outputs without any assumptions. The simultaneous equations of the second-order expansion of the Taylor series are then established. Finally, the corresponding coefficients can be calculated by solving the simultaneous equations. These new coefficients can be used in optimal real and reactive power dispatch problems. The proposed approach is tested by IEEE 14-bus and 30-bus systems, and the results are compared with those obtained from the traditional B coefficient method and the load flow method. The numerical results show that the proposed new loss formula for ED can hold high accuracy for different loading conditions and is very suitable for real-time applications.

23 April 2023 in Machines
Verified
Journal Article
Open access
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KYKai-chao Yao
Kai-chao Yao
Wei-Tzer HuangWei-Tzer Huang
Wei-Tzer Huang
JXJing-Ran Xu
Jing-Ran Xu
SHShu-Hua Huang
Shu-Hua Huang
CTChin-Tang Tsai
Chin-Tang Tsai
CLChun-Chung Liao
Chun-Chung Liao
This study investigated the application of the TRIZ innovation system method to bicycle handlebars and used a satisfaction survey to evaluate whether the bicycle handlebars met the users’ requirements, in order to reduce the cost and time needed for product development. First, we conducted a literature search and expert consultation, to explore the improvement requirements for handlebar design and bicycle motion injury; then, we used a contradiction matrix and the invention principle of the TRIZ method for analysis and design; and finally we used a human–machine system and the human measurement method of human factor engineering to analyze the user and bicycle handlebar operation and related dimensional definitions, as a reference for the design and to make a prototype bicycle handlebar. The SERVQUAL questionnaire was developed to compare the differences between the designed bicycle handlebar prototype and commercially available bicycle handlebars, and a practical analysis of the design was conducted using a two-dimensional quality model (Kano model) and the important–performance analysis method (IPA). Research results: 1. Innovative design of the bicycle handlebars: the development of height adjustment slots, front and rear angle design, front and rear swivel left and right extension mechanism, the user can clearly determine the current position and adjust to the most comfortable position to avoid waist, cervical vertebrae, and arm injuries. 2. Satisfaction assessment of bicycle handlebar innovation design: analyse the importance and satisfaction of bicycle handlebar innovation design, determine the production time and mass production value of the product, use questionnaires to conduct IPA and Kano model cross-analysis matrix, in order to reduce the time and cost required for product development.