Study on an Optimal Control Method for Energy Injection Resonant AC/AC High Frequency Converters

Su, Yu-Gang,Dai, Xin,Wang, Zhi-Hui,Tang, Chun-Sen,Sun, Yue The Korean Institute of Power Electronics 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.2

In energy injection resonant AC-AC converters, due to the low frequency effect of the AC input envelope and the low energy injection losses requirement, the constant and steady control of the high frequency AC output envelope is still a problem that has not been solved very well. With the aid of system modeling, this paper analyzes the mechanism of the envelope pit on the resonant AC current. The computing methods for the critical damping point, the falling time and the bottom value of the envelope pit are presented as well. Furthermore, this paper concludes the stability precondition of the system AC output. Accordingly, an optimal control method for the AC output envelope is put forward based on the envelope prediction model. This control method can predict system responses dynamically under different series of control decisions. In addition, this control method can select best series of control decisions to make the AC output envelope stable and constant. Simulation and experimental results for a contactless power transfer system verify the control method.

Study on an Optimal Control Method for Energy Injection Resonant AC/AC High Frequency Converters

Yu-Gang Su,Xin Dai,Zhi-Hui Wang,Chun-Sen Tang,Yue Sun 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.2

In energy injection resonant AC-AC converters, due to the low frequency effect of the AC input envelope and the low energy injection losses requirement, the constant and steady control of the high frequency AC output envelope is still a problem that has not been solved very well. With the aid of system modeling, this paper analyzes the mechanism of the envelope pit on the resonant AC current. The computing methods for the critical damping point, the falling time and the bottom value of the envelope pit are presented as well. Furthermore, this paper concludes the stability precondition of the system AC output. Accordingly, an optimal control method for the AC output envelope is put forward based on the envelope prediction model. This control method can predict system responses dynamically under different series of control decisions. In addition, this control method can select best series of control decisions to make the AC output envelope stable and constant. Simulation and experimental results for a contactless power transfer system verify the control method.

A Shared Channel Design for the Power and Signal Transfers of Electric-field Coupled Power Transfer Systems

Yu-Gang Su,Wei Zhou,Aiguo Patrick Hu,Chun-Sen Tang,Rong Hua 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

Electric-field coupled power transfer (ECPT) systems have been proposed as an alternative wireless power transfer (WPT) technology in recent years. With the use of capacitive plates as a coupling structure, ECPT systems have many advantages such as design flexibility, reduced volume of the coupling structure and metal penetration ability. In addition, wireless communications are effective solutions to improve the safety and controllability of ECPT systems. This paper proposes a power and signal shared channel for electric-field coupled power transfer systems. The shared channel includes two similar electrical circuits with a band pass filter and a signal detection resistor in each. This is designed based on the traditional current-fed push-pull topology. An analysis of the mutual interference between the power and signal transmission, the channel power and signal attenuations, and the dynamic characteristic of the signal channel are conducted to determine the values for the electrical components of the proposed shared channel. Experimental results show that the designed channel can transfer over 100W of output power and data with a data rate from 300bps to 120 kbps.

A Shared Channel Design for the Power and Signal Transfers of Electric-field Coupled Power Transfer Systems

Su, Yu-Gang,Zhou, Wei,Hu, Aiguo Patrick,Tang, Chun-Sen,Hua, Rong The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

Electric-field coupled power transfer (ECPT) systems have been proposed as an alternative wireless power transfer (WPT) technology in recent years. With the use of capacitive plates as a coupling structure, ECPT systems have many advantages such as design flexibility, reduced volume of the coupling structure and metal penetration ability. In addition, wireless communications are effective solutions to improve the safety and controllability of ECPT systems. This paper proposes a power and signal shared channel for electric-field coupled power transfer systems. The shared channel includes two similar electrical circuits with a band pass filter and a signal detection resistor in each. This is designed based on the traditional current-fed push-pull topology. An analysis of the mutual interference between the power and signal transmission, the channel power and signal attenuations, and the dynamic characteristic of the signal channel are conducted to determine the values for the electrical components of the proposed shared channel. Experimental results show that the designed channel can transfer over 100W of output power and data with a data rate from 300bps to 120 kbps.

Microvascular autologous submandibular gland transplantation in severe cases of keratoconjunctivitis sicca

Su, Jia-Zeng,Cai, Zhi-Gang,Yu, Guang-Yan Korean Association of Maxillofacial Plastic and Re 2015 Maxillofacial Plastic Reconstructive Surgery Vol.37 No.-

Dry eye syndrome is a relatively common disease of the tears and ocular surfaces that results in discomfort, visual disturbance, and tear film instability with possible damage to the ocular surfaces. Microvascular submandibular gland (SMG) transfer offers a surgical alternative for a permanent autologous substitution of tears using the basal secretion of a transplanted SMG. Long-term follow-up reveals that this technique is a lasting and effective solution for patients with severe dry eye syndrome. The uncomfortable symptoms were relieved, and the frequency of use of pharmaceutical tear substitutes was reduced. Objective examination showed significant improvement in tear film and some features of ocular surface such as breakup time of tear film and corneal staining. Patients may suffer from obstruction of Wharton's duct or epiphora after surgery. Activation of secretion-related receptors could improve the early hypofunction of the denervated SMG and prevent the duct obstruction. Reduction surgery, partial SMG transplantation, uses of atropine gel or Botulinum toxin A could be the choices of treatment for epiphora.

고관절 골성 강직에서의 전환 인공고관절 전치환술

유명철 ( Yu Myeong Cheol ),조윤제 ( Jo Yun Je ),김강일 ( Kim Gang Il ),전영수 ( Jeon Yeong Su ),이영호 ( Lee Yeong Ho ),하정한 ( Ha Jeong Han ) 대한고관절학회 2003 Hip and Pelvis Vol.15 No.1

병원 영상의학과 응급검사실의 검사가운 개선을 위한 연구

최유진(Yu-jin Choi),장동혁(Dong-hyuk Jang),강현수(Hyeon-su Gang),김대중(Dae-jung Kim),이신원(Sin-won Lee) 대한영상의학기술학회 2017 대한영상의학기술학회 논문지 Vol.2017 No.1

목 적 : 병원 영상의학과 응급검사실의 검사가운 현황 및 문제점을 파악하여 개선안을 마련하는데 도움을 주고자 하였다. 대상 및 방법 : 2016년 9월 1일부터 31일까지 일부병원 응급의료센터에 내원하여 영상의학과 응급검사실을 이용한 검사건수를 표본조사하고 성별, 연령대별, 탈의가 필요했던 검사 등으로 구분하여 분석하였다. 서울과 경기지역 대학병원급 20개 병원을 선정하여 검사용 가운 여부와 현황을 조사하였으며, 일부 병원 방사선사 48명을 대상으로 이와 관련된 인식을 설문조사를 하였다. 결 과 : 연구 기간의 총 검사 건수는 2953건 이었으며, 이 가운데 탈의가 필요한 검사건수는 남자가 1143명(38.7%), 여자는 1217명(41.2%) 이었다. 응급실에 검사용 가운이 준비되어 있지 않은 경우는 9개 병원(45%) 이었으며, 6개 병원(30%)에서 방사선사가 주사선을 처리하고 있었다. 가운이 없는 병원 가운데 5개 병원(55%)에서 방사선사가 주사선을 처리하고 있었다(p<0.005). 방사선사의 주사선 연결뚜껑 교체는 47명(97.9%)이 잘못된 것으로 인식하고 있었으며, 21명(43.8%)이 불법의료행위라고 하였다. 남자 방사선사 34명(87.2%)은 여성의 탈의에 도움을 준 경험이 있고, 38명(97.4%)은 성추행 관련 오해를 의식하며 근무한다고 하였다. 결 론 : 응급검사실 이송 전 검사가운의 착용으로 감염 등 안전사고 예방이 가능하며 응급 환자의 검사 대기시간 감소 및 기타 서비스의 제공에도 도움을 줄 수 있는 것으로 생각된다. Purpose : To identify the status and problem of examination gowns at the emergency laboratory under the Dept. of Radiology and help put forward a reform plan. SUBJECT and METHOD : The test cases from the patients who visited the emergency medical center of some hospitals and used the emergency laboratory under the Dept. of Radiology, from September 1 to 31, 2016, were sampled and then analyzed according to gender, age, and whether to undress. A total of 20 university hospital-scale hospitals were selected across Seoul and Gyeonggi Province to identify whether to have examination gowns and the present status of their use. In addition, a survey of the awareness about examination gowns was conducted on 48 Radiological technologist working at some hospitals. Result : A total of 2,953 test cases were used over the period of this study. The number of tests in need of undressing was 1,143 (38.7%) in males and 1,217 (41.2%) in females. There were 9 hospitals (45%) which did not have examination gowns in the emergency room, and 6 hospitals (30%) where Radiological technologist were in charge of handling scanning lines. Among the hospitals without gowns, to be specific, there were 5 hospitals hospitals (55%) where Radiological technologist were in charge of handling scanning lines (p<0.005). When it comes to the awareness about Radiological technologist replacing the lock injection cap, 47 radiologists (97.9%) answered that it was wrong, and 21 Radiological technologist (43.8%) answered that it was an illegal medical treatment. Meanwhile, 34 male Radiological technologist (87.2%) said that they had experience of helping female patients undress, and 38 male Radiological technologist (97.4%) said that they were always mindful of misunderstandings related to sexual harassment when they worked. CONCLUSION : It is evaluated that wearing an examination gown before moving to the emergency laboratory can prevent any safety accident such as infection, and help to reduce the waiting time of emergency patients and provide other services.

Theoretical Studies on Mechanism and Kinetics of the Hydrogen-Abstraction Reaction of CF_3CH_2CHO with OH Radicals

Cheng-gang Ci,Hong-bo Yu,Su-qin Wan,Jing-yao Liu,Chia-Chung Sun 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.4

The hydrogen abstraction reaction of CF_3CH_2CHO + OH has been studied theoretically by dual-level direct dynamics method. Two stable conformers, trans- and cis-CF_3CH_2CHO, have been located, and there are four distinct OH hydrogen-abstraction channels from t-CF_3CH_2CHO and two channels from c-CF_3CH_2CHO. The required potential energy surface information for the kinetic calculation was obtained at the MCG3-MPWB//M06-2X/aug-cc-pVDZ level. The rate constants, which were calculated using improved canonical transitionstate theory with small-curvature tunneling correction (ICVT/SCT) were fitted by a four-parameter Arrhenius equation. It is shown that the reaction proceeds predominantly via the H-abstraction from the -CHO group over the temperature range 200-2000 K. The calculated rate constants were in good agreement with the experimental data between 263 and 358 K.

ERRATUM Bull. Korean Chem. Soc. 2011, Vol. 32, No. 4, pp 1187~1194

Cheng-gang Ci,Hong-bo Yu,Su-qin Wan,Jing-yao Liu,Chia-Chung Sun 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.7

Shaking Table Test on Seismic Responses of a Monolithic Precast Concrete Shear Wall Structure

Chao-gang Qin,Guoliang Bai,Ya-zhou Xu,Ning Fen Su,Tao Wu,Zhong Liang Li,Yu Zhe Sun 대한토목학회 2018 KSCE Journal of Civil Engineering Vol.22 No.10

To examine the seismic performance of Monolithic Precast Concrete Shear Wall (MPCSW) structure, a 1/5-scaled twelve-story model is designed and investigated by shaking table test, and connections between the precast elements and their impact on seismic performance of the overall model are comprehensively inspected and analyzed. Based on the testing results, the structural responses are divided into elastic stage and plastic stage, and the variations of dynamic characteristics, cracking and failure pattern, seismic responses of the model are accordingly presented. The experimental results indicate that most of critical cracks of the MPCSW model locate on the coupling beams and horizontal connections of precast concrete shear walls, and the fundamental frequency exhibits a successively decreasing trend during the entire testing process. Furthermore, The MPCSW model is designed in accordance with Chinese codes meets the requirement for the seismic fortification intensity of eight, and shows an adequate safety margin to resist collapse in the case of 0.90 g.