Maximization of Transmission System Loadability with Optimal FACTS Installation Strategy

Ya-Chin Chang,Rung-Fang Chang 대한전기학회 2013 Journal of Electrical Engineering & Technology Vol.8 No.5

Instead of building new substations or transmission lines, proper installation of flexible AC transmission systems (FACTS) devices can make the transmission networks accommodate more power transfers with less expansion cost. In this paper, the problem to maximize power system loadability by optimally installing two types of FACTS devices, namely static var compensator (SVC) and thyristor controlled series compensator (TCSC), is formulated as a mixed discrete-continuous nonlinear optimization problem (MDCP). To reduce the complexity of the problem, the locations suitable for SVC and TCSC installations are first investigated with tangent vector technique and real power flow performance index (PI) sensitivity factor and, with the specified locations for SVC and TCSC installations, a set of schemes is formed. For each scheme with the specific locations for SVC and TCSC installations, the MDCP is reduced to a continuous nonlinear optimization problem and the computing efficiency can be largely improved. Finally, to cope with the technical and economic concerns simultaneously, the scheme with the biggest utilization index value is recommended. The IEEE-14 bus system and a practical power system are used to validate the proposed method.

Maximization of Transmission System Loadability with Optimal FACTS Installation Strategy

Chang, Ya-Chin,Chang, Rung-Fang The Korean Institute of Electrical Engineers 2013 Journal of Electrical Engineering & Technology Vol.8 No.5

Instead of building new substations or transmission lines, proper installation of flexible AC transmission systems (FACTS) devices can make the transmission networks accommodate more power transfers with less expansion cost. In this paper, the problem to maximize power system loadability by optimally installing two types of FACTS devices, namely static var compensator (SVC) and thyristor controlled series compensator (TCSC), is formulated as a mixed discrete-continuous nonlinear optimization problem (MDCP). To reduce the complexity of the problem, the locations suitable for SVC and TCSC installations are first investigated with tangent vector technique and real power flow performance index (PI) sensitivity factor and, with the specified locations for SVC and TCSC installations, a set of schemes is formed. For each scheme with the specific locations for SVC and TCSC installations, the MDCP is reduced to a continuous nonlinear optimization problem and the computing efficiency can be largely improved. Finally, to cope with the technical and economic concerns simultaneously, the scheme with the biggest utilization index value is recommended. The IEEE-14 bus system and a practical power system are used to validate the proposed method.

Fitness Sharing Particle Swarm Optimization Approach to FACTS Installation for Transmission System Loadability Enhancement

Chang, Ya-Chin The Korean Institute of Electrical Engineers 2013 Journal of Electrical Engineering & Technology Vol.8 No.1

Proper installation of Flexible AC Transmission Systems (FACTS) devices in existing transmission networks can enable power systems to accommodate more power transfer with less network expansion cost. The problem to maximize transmission system loadability by determining optimal locations and settings for installations of two types of FACTS devices, namely static var compensator (SVC) and thyristor controlled series compensator (TCSC), is formulated as a mixed discrete-continuous nonlinear optimization problem (MDCP). For solving the MDCP, in the paper, the proposed method with fitness sharing technique involved in the updating process of the particle swarm optimization (PSO) algorithm, can diversify the particles over the search regions as much as possible, making it possible to achieve the optimal solution with a big probability. The modified IEEE-14 bus network and a practical power system are used to validate the proposed method.

An 8-Week Low-Intensity Progressive Cycling Training Improves Motor Functions in Patients with Early-Stage Parkinson’s Disease

Hsiu-Chen Chang,Chin-Song Lu,Wei-Da Chiou,Chiung-Chu Chen,Yi-Hsin Weng,Ya-Ju Chang 대한신경과학회 2018 Journal of Clinical Neurology Vol.14 No.2

Background and Purpose The effects of high-intensity cycling as an adjuvant therapy forearly-stage Parkinson’s disease (PD) were highlighted recently. However, patients experience difficultiesin maintaining these cycling training programs. The present study investigated the efficacyof cycling at a mild-to-moderate intensity in early-stage PD. Methods Thirteen PD patients were enrolled for 16 serial cycling sessions over a 2-month period. Motor function was assessed using the Unified Parkinson’s Disease Rating Scale part III(UPDRS III) and Timed Up and Go (TUG) test as primary outcomes. The Montreal CognitiveAssessment (MoCA), modified Hoehn and Yahr Stage (mHYS), total UPDRS, Falls EfficacyScale, New Freezing of Gait Questionnaire, Schwab and England Activities of Daily Living, 39-item Parkinson’s Disease Questionnaire, Patient Global Impression of Change, and gait performancewere assessed as secondary outcomes. Results The age and the age at onset were 59.67±7.24 and 53.23±10.26 years (mean±SD), respectively. The cycling cadence was 53.27±8.92 revolutions per minute. The UPDRS III scoreimproved significantly after 8 training sessions (p=0.011) and 16 training sessions (T2) (p=0.001) in the off-state, and at T2 (p=0.004) in the on-state compared to pretraining (T0). TheTUG duration was significantly shorter at T2 than at T0 (p<0.05). The findings of MoCA, totalUPDRS, double limb support time, and mHYS (in both the off- and on-states) also improvedsignificantly at T2. Conclusions Our pioneer study has demonstrated that a low-intensity progressive cycling exercisecan improve motor function in PD, especially akinesia. The beneficial effects were similarto those of high-intensity rehabilitation programs.

The effectiveness of using the barcode information system to check the property and equipment of outpatient clinics

Ya-Wen Chang,Chin-Ling Lee 한국간호과학회 2023 한국간호과학회 학술대회 Vol.2023 No.11

A Robust and Removable Watermarking Scheme Using Singular Value Decomposition

( Ya-feng Di ),( Chin-feng Lee ),( Zhi-hui Wang ),( Chin-chen Chang ),( Jianjun Li ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.12

Digital watermarking techniques are widely applied to protect the integrity and copyright of digital content. In a majority of the literature for watermarking techniques, the watermarked image often causes some distortions after embedding a watermark. For image-quality-concerned users, the distortions from a watermarked image are unacceptable. In this article, we propose a removable watermarking scheme that can restore an original-like image and resist signal-processing attacks to protect the ownership of an image by utilizing the property of singular value decomposition (SVD). The experimental results reveal that the proposed scheme meets the requirements of watermarking robustness, and also reestablishes an image like the original with average PSNR values of 59.07 dB for reconstructed images.

Effect of Active Synthetic 2-Substituted Quinazolinones on Anti-Platelet Aggregation and the Inhibition of Superoxide Anion Generation by Neutrophils

Chang, Fang-Rong,Wu, Chin-Chung,Hwang, Tsong-Long,Patnam, Ramesh,Kuo, Reen-Yen,Wang, Wei-Ya,Lan, Yu-Hsuan,Wu, Yang-Chang The Pharmaceutical Society of Korea 2003 Archives of Pharmacal Research Vol.26 No.7

Quinazolinones, 2-substituted and 3-substituted, mainly synthesized by microwave irradiation, were subjected to anti-platelet aggregation and inhibition of superoxide anion generation assays. Interestingly, 2-phenyl-4-quinazolinone (4) exhibited significant inhibitory activities toward platelet aggregation and neutrophil activation, and it might therefore serve as a prototype lead compound.

A Robust and Removable Watermarking Scheme Using Singular Value Decomposition

Di, Ya-Feng,Lee, Chin-Feng,Wang, Zhi-Hui,Chang, Chin-Chen,Li, Jianjun Korean Society for Internet Information 2016 KSII Transactions on Internet and Information Syst Vol.10 No.12

Digital watermarking techniques are widely applied to protect the integrity and copyright of digital content. In a majority of the literature for watermarking techniques, the watermarked image often causes some distortions after embedding a watermark. For image-quality-concerned users, the distortions from a watermarked image are unacceptable. In this article, we propose a removable watermarking scheme that can restore an original-like image and resist signal-processing attacks to protect the ownership of an image by utilizing the property of singular value decomposition (SVD). The experimental results reveal that the proposed scheme meets the requirements of watermarking robustness, and also reestablishes an image like the original with average PSNR values of 59.07 dB for reconstructed images.

Research on the Critical Factors Affecting Taiwan Secondary School Teachers' Initial Acquisition of Formal Teaching Position

Tien, Shiaw-Wen,Chiu, Chung-Ching,Tsai, Chih-Hung,Chung, Yi-Chan,Chang, Ya-Chin The Korean Society for Quality Management 2007 The Asian Journal on Quality Vol.8 No.3

This research treated the secondary school teachers as the research scale and the research targets included the following: secondary school (employ unit), center of teacher education, and qualified teachers. In terms of these three groups of people, the topics of exploration focused on the perception of suitable teachers, perception of evaluation standard during the process of teacher examination and the relationship among teacher examination systems. The research was managed by two phases: the first phase referred to literature reorganization, expert interview, the qualities and conditions of suitable teachers, important evaluation standard during the process of teacher examination and teacher examination system used; the second phase included questionnaire survey, employ school acquisition, the perception of centers of teacher education and qualified teachers toward the suitability condition and examination evaluation standard in the first phase and teacher examination system used. This research found out that as to the perception of suitable teachers, through data collection, there were six factors reorganized. The levels of their importance were as follows: education devotion, teaching capacity, class management, capacity to guide special students, capacity to communicate with the parents and the will to undertake administrative works. Noticeably, employee unit and centers of teacher education apparently valued class management more, compared with trained teachers; as to evaluation standard of examination, the analytical result found out that the perception of three groups were different in terms of the views toward educational works, written examination data, candidate's age, club experience at school and capacity to use multimedia support teaching materials. This research further proposed six suggestions for centers of teacher education and trained teachers: (l) employ schools considerably valued educational devotion; (2) trained teachers tended to neglect the importance of class management; (3) employee unit considerably cared about the new teachers' competence to use multimedia support teaching materials; however, trained teachers did not have the same view; (4) employee unit considerably cared about new teachers' views toward educational works as well as the candidates' ages; (5) generally speaking, trained teachers neglected the importance of club experience at school; (6) the data revealed that written examination data was not relatively important in terms of teacher examination.

Interleukin-20 targets podocytes and is upregulated in experimental murine diabetic nephropathy

Yu-Hsiang Hsu,Hsing-Hui Li,Junne-Ming Sung,Wei-Yu Chen,Ya-Chin Hou,Yun-Han Weng,Wei-Ting Lai,Chih-Hsing Wu,Ming-Shi Chang 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Interleukin (IL)-20, a proinflammatory cytokine of the IL-10 family, is involved in acute and chronic renal failure. The aim of this study was to elucidate the role of IL-20 during diabetic nephropathy development. We found that IL-20 and its receptor IL-20R1 were upregulated in the kidneys of mice and rats with STZ-induced diabetes. In vitro, IL-20 induced MMP-9, MCP-1, TGF-β1 and VEGF expression in podocytes. IL-20 was upregulated by hydrogen peroxide, high-dose glucose and TGF-β1. In addition, IL-20 induced apoptosis in podocytes by activating caspase-8. In STZ-induced early diabetic nephropathy, IL-20R1-deficient mice had lower blood glucose and serum BUN levels and a smaller glomerular area than did wild-type controls. Anti-IL-20 monoclonal antibody (7E) treatment reduced blood glucose and the glomerular area and improved renal functions in mice in the early stage of STZ-induced diabetic nephropathy. ELISA showed that the serum IL-20 level was higher in patients with diabetes mellitus than in healthy controls. The findings of this study suggest that IL-20 induces cell apoptosis of podocytes and plays a role in the pathogenesis of early diabetic nephropathy.