싱가폴 국립대학교(NUS) Woei Wan Tan 교수 인터뷰

Woei Wan Tan,최기흥 한국공학교육학회 2013 Ingenium(人材니움) Vol.20 No.4

WoeiWan Tan graduated with the Bachelor of Engineering (Electrical, Honours) degree and theMaster of Engineering degree from the National University of Singapore. After earning the Doctor of Philosophy degree from the University of Oxford for her work on self-learning neurofuzzy control of nonlinear systems, she joined the National University of Singapore where she is currently an Associate Professor. She is also serving as an Associate Head (Undergraduate Programmes) in the Department of Electrical & Computer Engineering, and as an Assistant Dean for the Faculty of Engineering External Relations Office. Her recent research interests are theoretical development of type-2 fuzzy systems, and the application of type-2 fuzzy systems to intelligent modelling, control and fault diagnosis. She also has interests in engineering education research, promotion of engineering education and experience with outcome-based accreditation processes.

싱가폴 국립대학교(NUS) Woei Wan Tan 교수 인터뷰

( Woei Wan Tan ),최기흥 한국공학교육학회(구 한국공학교육기술학회) 2013 공학교육동향 Vol.20 No.4

A Study of the Impact Deformation and Fracture Behaviour of Austenitic Manganese Steel

Woei Shyan Lee,Bo Kai Wang 대한금속ᆞ재료학회 2006 METALS AND MATERIALS International Vol.12 No.6

Cultivating creative problem solvers: the PBL style

Woei Hung 서울대학교 교육연구소 2015 Asia Pacific Education Review Vol.16 No.2

After decades of research, we now know that creativity is a multidimensional construct that involves variables from the domains of personality, environment, and cognition. A construct with such level of complexity, as we know from past research, cannot be effectively learned through traditional lecture-based instruction. Rather, the formation of this type of ability is a cultivation process. Problem-based learning (PBL) is an instructional method that holds promise for cultivating students’ creativity. The characteristics of PBL provide well-aligned instructional affordance for not only fostering students’ development of necessary ability, knowledge, and skills for creativity to occur, but also providing a learning environment that supports the cultivation process. In this paper, an analysis of the characteristics of creativity as well as a description of the main features of PBL will be discussed. Furthermore, the details of the alignment between PBL’s affordance and the characteristics of creativity will also be provided.

Maximum Voltage Point Tracking for Partially-Shaded PV Modules

Woei-Luen Chen,Zih-Shan Lai,Wen-Hsuan Huang 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

The output power of a photovoltaic (PV) string would decline drastically when a few of the PV modules in the string are subject to partial shading conditions (PSC). To restore part of power loss caused by the PSC, the output currents of the series PV modules should match to each other. In achieving this, a micro-converter is disposed at the terminal of each PV module and behaves like a current transformer. Once the best current of the PV string is determined, the micro-converter must contribute not only compatible current but as large terminal voltage as possible. An algorithm of maximum voltage point tracking (MVPT) is presented to maximize the micro-converter terminal voltage so that the operating point of the series PV modules can go toward respective maximum power points (MPP) and guarantee the power peak uniqueness. The experimental results show that the proposed MVPT for each PV module is autonomous and capable of tracking global maximum power point (GMPP) for a PV string.

Development of microporous substrates of polyamide thin film composite membranes for pressure-driven and osmotically-driven membrane processes: A review

Woei Jye Lau,Gwo-Sung Lai,Jian-xin Li,Stephen Gray,Yunxia Hu,Nurasyikin Misdan,PEI SEAN GOH,Takeshi Matsuura,Ihsan Wan Azelee,Ahmad Fauzi Ismail 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.77 No.-

Polyamide thinfilm composite (TFC) membranes are state-of-the-art membranes with superiorpermeability and selectivity, and are widely used in various membrane-based processes for desalination,wastewater treatment and other separation applications. Over the past 15 years, there has been growinginterest among membrane scientists to study the role of the polymeric substrates and perform in-depthanalyses on how changes in the substrate physicochemical properties could affect polyamide layer structureand thus membrane performance. Recent advancements in new polymeric materials development andnanomaterial synthesis have led to opportunities for new generation substrate development. Consideringthe importance of TFC membranes for industrial separation process, this review will give a state-of-the-artaccount of the subject matter by emphasizing substrates made by different techniques and variousmaterials. More specifically, the article will review the roles of the developed substrates on thephysiochemical properties of polyamide selective layer and further their influences on TFC membraneperformance for both pressure-driven (nanofiltration/reverse osmosis) and osmotically-driven (forwardosmosis/pressure retarded osmosis) processes, aiming to stimulate progress in thefield. A framework forbetter understanding the substrate development to fulfill the industrial requirements of TFC membraneapplication will also be presented in this review before ending with future perspectives.

Dynamic Symmetrical Components Analysis and Compensation for Unbalanced Distribution Systems

Woei-Luen Chen,Bing-Syuan Lin,Meng-Jie Wang 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

The short circuit fault and the unbalanced three-phase loads are the common reasons causing unbalanced voltage distortion (UVD) in the distribution system. In the past, the decline in electric motor performance and life cycle was a well-known fact caused by UVD. However, the UVD deserves more attention in recent years due to the rapid growth of the wind power penetration in the distribution system. The wind power system operated under the UVD suffers not only the pulsation torque but also penetrates unbalanced current and consequently deteriorates the UVD of the distribution system. This paper presents an approach to dynamically resolve the symmetrical components from the three-phase instantaneous voltages in order to clarify the degree of the UVD for compensation. The vector representation for the symmetrical components involves the information of angular frequency into the steady-state phasor, which can push much of the complexity down on the controller design for compensating the UVD. A dynamic voltage restorer (DVR) is employed as a voltage compensator in the series path of the feeder for refining the percent voltage unbalance of the UVD. The impact of the UVD reduction on a grid-tied 3-kW squirrel cage induction generator (SCIG) shows the effectiveness of the proposed approach.

Design of the PID Controller for Hydro-turbines Based on Optimization Algorithms

Jau-Woei Perng,Yi-Chang Kuo,Kuan-Chung Lu 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.7

In this study, multiple objective particle swarm optimization (MOPSO), genetic algorithm, bees, and reinforcement learning (RL) are used to calculate the rise time (tr), integral square-error, integral of time-multipliedsquared-error, integral absolute error, and integral of time multiplied by absolute error of the system transfer function and then we use a fuzzy algorithm on MOPSO, GA, bees, and RL based on the frequency sensitivity margin of a water turbine governor to optimize the proportional gain (kp) and integral gain (ki) and calculate the relative collapsing frequency response values. The MOPSO algorithm returned the optimal result. The radial basis function (RBF) neural network curve is obtained from the MOPSO algorithm with three variables (i.e., kp, ki, kd = 0.6 and grid frequency deviations values), and finally we identify and predict three variable values near the RBF neural network curve through deep learning. The result of the grid frequency deviation is close to 0, and the gain response time is better for damping the frequency oscillations in different operating conditions.

Chemical Composition and Antimicrobial Efficacy of Helminthostachys zeylanica against Foodborne Bacillus cereus

Tong Woei Yenn,Leong Chean Ring,Khairul Azly Zahan,Muhammad Sharir Abdul Rahman,Wen-Nee Tan,Bintul Jauza’ Shaik Alaudin 한국생약학회 2018 Natural Product Sciences Vol.24 No.1

Helminthostachys zeylanica is a rare plant grows in lightly shaded areas. The fern was traditionally used as antipyretic and antiphlogistic agents. This study was aimed to evaluate the antibacterial potential of H. zeylanica on foodborne Bacillus cereus. The chemical composition of its ethanolic extract was also determined. The plant samples were collected at Kampung Kebun Relong, Kedah, Malaysia. The ethanolic extract showed significant inhibitory activity on B. cereus with a sizeable clear zone detected on disc diffusion assay. On broth microdilution assay, the MIC of the extract on B. cereus was 6.25 mg/ml and the MBC was 12.5 mg/ml. The inhibitory activity of the extract on B. cereus was bactericidal. In the growth dynamic study, the antibacterial efficacy of the extract was concentration dependent, where a lower colony forming unit count was obtained with increased extract concentration. The SEM micrograph of extract treated B. cereus cells showed invaginations of cell wall. The bacterial cell structure collapsed after 24 h exposure to the extract. The GCMS analysis of the extract showed that the major constituents of the extract were phenol (36.26%) and quercetin (29.70%). This study is important as it shows the potential use of H. zeylanica as an effective agent to control B. cereus related infections.

Enhancement of Anti-candidal Activity of Endophytic Fungus Phomopsis sp. ED2, Isolated from Orthosiphon stamineus Benth, by Incorporation of Host Plant Extract in Culture Medium

Tong Woei Yenn,Chong Chai Lee,Darah Ibrahim,Latiffah Zakaria 한국미생물학회 2012 The journal of microbiology Vol.50 No.4

This study examined the effect of host extract in the culture medium on anti-candidal activity of Phomopsis sp. ED2,previously isolated from the medicinal herb Orthosiphon stamineus Benth. Interestingly, upon addition of aqueous host extract to the culture medium, the ethyl acetate extract prepared from fermentative broth exhibited moderate anticandidal activity in a disc diffusion assay. The minimal inhibitory concentration of this extract was 62.5 μg/ml and it only exhibited fungistatic activity against C. albicans. In the time-kill study, a 50% growth reduction of C. albicans was observed at 31.4 h for extract from the culture incorporating host extract. In the bioautography assay, only one single spot (Rf 0.59) developed from the extract exhibited anti-candidal activity. A spot with the a similar Rf was not detected for the crude extract from YES broth without host extract. This indicated that the terpenoid anti-candidal compound was only produced when the host extract was introduced into the medium. The study concluded that the incorporation of aqueous extract of the host plant into the culture medium significantly enhanced the anti-candidal activity of Phomopsis sp. ED2.