Modular DC Solid State Transformer with Fault-Tolerant Function

Xiangqi Meng,Yanbing Jia,Chunguang Ren,Xiaoqiang Lin,Baifu Zhang 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

A modularized control method with faulttolerant function is proposed under the condition that a module of DC solid state transformer (DCSST) fails due to input short circuit. The decoupling control strategy is deduced by establishing the mathematic model of the DCSST. The maximum input voltage is selected as the reference voltage by adding diodes at the input side. The proposed system can automatically adjust the input voltage reference to keep the output voltage stability for the module in DCSST with short-circuit fault. Simulation and experiment results show that the proposed control method can decouple the output voltage and the input average voltage, maintain the output voltage stable and improve the reliability of the system when a short circuit occurs in a module of DCSST.

A Comparative Study of Korea and Qingdao’s Long-term Care Insurance Policy and its Enlightenment

김근홍(Kim Keunhong),맹상기(MENG Xiangqi) 한국노년학회 2018 한국노년학 Vol.38 No.3

본 연구의 목적은 정책 비교를 통한 한국의 장기요양보험 제도가 중국 청도의 장기요양보험 시스템 구축에 미치는 영향과 시사점을 검토하는데 있다. 중국과 한국의 문화배경, 생활습관 및 인구구조 등 다양한 측면에서 매우 유사하여 한국 장기요양보험의 성공적인 경험은 중국 청도의 장기요양보험 제도를 구축하는 데 큰 도움이 될 것으로 판단된다. 이에 본 연구는 문헌연구를 통해 Gilbert & Terrell의 사회복지정책분석 프레임워크에서 청도와 한국의 장기요양보험 정책을 비교해 보았다. 정책비교를 통해 청도의 현재 시범 정책 문제점들로 입법 지원 부족, 재정 독립 그리고 심사 기준 등이 명확하지 않고 인적자원 부족을 논의하였다. 이에 다양한 차원에서의 정책비교를 통해 법제 지원, 평가기준 상세화, 혜택범주 확대화, 서비스네트워크 강화, 재원 최적화를 위해 청도의 장기요양보험 개선 제안들을 결론으로 제시해 보았다. The purpose of this study is to explore the enlightenment of the Korean long-term care insurance policy on Qingdao’s long-term care insurance policy through policy comparison. China and Korea are very similar in terms of cultural background, living habits, and population structure. Therefore, the successful experience of Korean long-term care insurance has great implications for Qingdao even China to build a long-term care insurance system. Through the literature review, this article compares the long-term care insurance policy implemented by Qingdao City and Korea in Gilbert & Terrell’s social welfare policy analysis framework. With the comparison this article discusses about the existing problems of the current pilot policy system in Qingdao, such as lack of legislation support and financial independence, assessment standards are not detailed, and human resources are insufficient. The author raises five suggestions to improve Qingdao’s long-term care policy as the conclusion of this paper: legislation support, detailed assessment standard, expand categories of benefits, enrich delivery network, optimize financing sources.

The Introduction of Long-term Care Insurance (LTCI) in China and Lessons from the Policy in South Korea: Focusing on the LTCI Pilot Programs of Shandong Province in China

Keun-hong Kim,Xiangqi Meng,Eun-whee Kang,Koung-won Seo,Song-hee Lee,Soon-deok Lee 한국사회적질학회 2021 사회적질연구 Vol.5 No.3

중국은 1979년 이후로 한자녀정책을 주요 정책으로 추진해왔고, 이로 인해 저출산 사회로 전환되었 다. 또한 발전된 보건과 의료기술로 노인들의 수명이 급격히 늘어나면서 중국의 고령화율 역시 급증하 였다. 이렇듯 수발이 필요한 고령인구는 급증하였으나, 현재 중국에는 이들을 돌볼 돌봄인력이나 인프 라가 턱없이 부족한 상태이다. 본 연구는 이러한 노인수발 문제를 해결하기 위한 제도적 해법으로 노인 장기요양보험에 주목한다. 본 연구는 중국 노인장기요양보험제도의 도입과정과 시범사업 등을 살펴본 후, 노인장기요양보험제도 도입의 선도국가인 한국으로부터 어떤 정책교훈을 얻을 수 있는지 살펴보았 다. 본 연구는 연구를 수행함에 있어 주로 문헌연구 분석을 사용하였다. 본 연구는 두 가지 의의를 갖는다. 첫째, 중국 노인장기요양보험제도의 시범사업을 개관함으로써 그 흐름은 물론 그에 관한 기초 자료를 제공하고 있다. 둘째, 중국의 노인수발 문제를 연구함에 있어 기존 연구들에서 찾아볼 수 없는 비교사회정책학적 접근법, 특히 동아시아 사회복지에 대한 비교연구를 수행하였다. China implemented the one-child policy in 1979 and has experienced its various negative effects since then. In particular, the social phenomenon during the transition of its society to an aging one is a representative example of the negative effects. During its transition to an aging society, China has been in a situation where it has had to deal with problems related to the elderly and family support that some East Asian countries such as Japan and South Korea has also experienced. With this as background, this study tried to focus on long-term care insurance for the elderly as an institutional solution for solving various problems that arose during its transition to an aging society. Specifically, the introduction process of long-term care insurance system for the elderly in China was examined, and some implications were obtained from the policies in South Korea, which is known as an advanced country regarding this system. Through various related literature and prior research, the study summarized the background to the introduction of the long-term care insurance system for the elderly in China, the progress of the trial program of the long-term care insurance system for the elderly in China, the expansion of the trial program, and implications of the long-term care insurance system for the elderly in South Korea. The implications of this study are as follows: First, this research is significant in that it will show how the pilot operation of China's long-term care insurance system flowed along with basic related data. Second, it is meaningful as South Korea’s long-term care insurance system was explored as an institutional way to address problems related to providing support for the elderly in China.

Mutant IDH1 Enhances Temozolomide Sensitivity via Regulation of the ATM/CHK2 Pathway in Glioma

Lin Lin,Jinquan Cai,Zixiao Tan,Xiangqi Meng,Ruiyan Li,Yang Li,Chuanlu Jiang 대한암학회 2021 Cancer Research and Treatment Vol.53 No.2

Purpose Isocitrate dehydrogenase 1 (IDH1) mutations are the most common genetic abnormalities in low-grade gliomas and secondary glioblastomas. Glioma patients with these mutations had better clinical outcomes. However, the effect of IDH1 mutation on drug sensitivity is still under debate. Materials and MethodsIDH1-R132H mutant cells were established by lentivirus. IDH1-R132H protein expression was confirmed by western blot. The expression of ataxia telangiectasia mutated (ATM) signaling pathway and apoptosis-related proteins were detected by immunofluorescence and western blot. Temozolomide (TMZ) induced cell apoptosis was detected by flow cytometry. Tumor cell proliferation was detected by Cell Counting Kit-8. In vivo nude mice were used to confirm the in vitro roles of IDH1 mutation.ResultsWe established glioma cell lines that expressed IDH1-R132H mutation stably. We found that TMZ inhibited glioma cells proliferation more significantly in IDH1 mutant cells compared to wild type. The IC50 of TMZ in IDH1-R132H mutant group was less than half that of wild-type group (p < 0.01). TMZ significantly induced more DNA damage (quantification of γH2AX expression in IDH1 mutation vs. wild type, p < 0.05) and apoptosis (quantification of AnnexinV+propidium iodide–cells in IDH1 mutation versus wild type, p < 0.01) in IDH1 mutant gliomas compared to wild-type gliomas. The ATM-associated DNA repair signal was impaired in IDH1 mutant cells. Inhibiting the ATM/checkpoint kinase 2DNA repair pathway further sensitized IDH1 mutant glioma cells to chemotherapy. We found that IDH1 mutation significantly inhibited tumor growth in vivo (the tumor size was analyzed statistically, p < 0.05). Moreover, we confirmed that gliomas with IDH1 mutation were more sensitive to TMZ in vivo compared to wild type significantly and the results were consistent with the in vitro experiment. ConclusionThese results provide evidence that combination of TMZ and ATM inhibitor enhances the antitumor effect in IDH1 mutant gliomas.

Unified coordination control strategy for DC solid‑state transformer in DC microgrid

Yanbing Jia,Pei Zhao,Jinjie Tian,Xiangqi Meng,Han Wu 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.8

The existing control strategies of DC solid-state transformer (DCSST) are based on DC distribution system, which is mainly concentrated on one side voltage stability control without considering the change of control objectives under different conditions. Thus, they are unsuitable for multiterminal and multisource DC microgrid. The coordinated control strategy of DCSST in multiterminal and multisource DC microgrid is studied in this paper. The DCSST circuit models based on the series–parallel structure of dual active full bridge converter are established, and the basic control modes are analyzed: control low voltage mode and control high voltage mode. Combined with the characteristics of DC bus voltage fluctuation and the operation conditions of DCSST, a unified coordinated control strategy is proposed. Experimental results show that the proposed control strategy can correctly identify the different power states of the two sides of the system, control the power exchange between the two sides of the system, and maintain the stable operation of the whole DC system.

노인복지기관 종사자의 윤리경영수준 인식에 대한 영향 요인 연구

임효순(Lim HyoSoon),김혜욱(Kim HyeWook),주현아(Joo HyeonAah),김성현(Kim SungHyun),맹상기(MENG XIANGQI) 한국노년학회 2018 한국노년학 Vol.38 No.3

본 연구는 노인복지기관의 윤리경영 수준 제고를 위한 기초자료를 제공하고자 노인복지기관 종사자의 일반적 특성과 기관 특성이 노인복지기관 종사자의 윤리경영수준 인식에 미치는 영향을 고찰하였다. 이를 위하여 편의 표집으로 조사한 서울시 및 경기도의 노인복지관에 종사하는 종사자 245명을 대상으로 구조화된 자기 기재방법 설문지를 이용하여 설문조사를 수행하였다. 독립변인인 일반적 특성 요인, 기관 특성 요인과 종속변수인 윤리경영수준 인식을 빈도분석, 백분율, 평균 등의 기술 통계분석을 통해 파악하였으며 각 독립변인별 윤리경영수준 인식의 차이를 t-test, ANOVA를 통해 비교ㆍ분석하였다. 또한 각각의 독립변인들이 윤리경영수준 인식에 미치는 영향을 다중회귀분석을 통해 파악하였다. 연구결과 일반적 특성에서는 여성보다 남성이, 교육수준이 높을수록 기관 특성에서는 윤리교육경험이 적을수록, 기관이 윤리적인 근무환경일수록 자신이 종사하고 있는 기관의 윤리경영수준을 높게 인식하는 것으로 조사되었다. 이러한 결과를 토대로 노인복지기관에서 윤리경영수준 인식을 제고하기 위해서는 무엇보다 기관 내의 실제적인 윤리적 근무환경과, 종사자를 대상으로 하며 구체적인 실천에까지 이르도록 하는 단계별 심화 윤리경영교육이 필요함을 확인할 수 있었다. 끝으로 본 연구는 소형화, 민영화 등 빠르게 변화하고 있는 노인복지 실천현장의 윤리경영수준 인식 제고를 위한 실천적 함의를 제시하였다는 점에서 연구의 의의를 지닌다고 하겠다. The purpose of this study is to investigate the effects of staffs’ general characteristics and institutional characteristics on the staff members’ recognition of the level of ethical management in the elderly welfare institutions and to provide basic materials for raising standard of ethical management in the elderly welfare institutions. For this purpose, we conducted a questionnaire survey using structured self-filling-type questionnaires for 245 staffs of elderly welfare institutions in Seoul and Gyeonggi-do. This study sets general characteristics of staffs and institutional characteristics as the independent variables and the staff members’ recognition of the level of ethical management as the dependent variable. The variables are investigated through the descriptive statistics such as frequency, percentage and average analysis, and the difference of effect on the staff members’recognition of ethical management in the elderly welfare institutions by each independent variable was analysed by t-test, ANOVA and multiple regression analysis. The results of the study shows that in terms of general characteristics of staffs, the higher male to female ratio and the higher educational level; and in institutional characteristics, the less experience in basic ethics education and the better ethical working environment of the institution are the positive factors for that the staff members estimate the level of ethical management of their workplace high. Based on these results, for making staff members recognize the level of ethical management in the elderly welfare institutions higher, we should create actual atmosphere of the ethical working environment in the institution and implement not formal but step-by-step intensive ethics education that make employees can apply it in the real situations. In conclusion, this study gives the practical suggestions for improving the staff members’ recognition of ethical management level in the practice field of elderly welfare on the fast-changing trends including downsizing and privatization.

The Formation Process and Current Issues of Regional Centers for Children

Ji-young Won,Bum-ki Park,Hee-kyung Kim,Soon-deok Lee,Mi-hye Lee,Xiangqi Meng 한국사회적질학회 2019 사회적질연구 Vol.3 No.2

Since the amendment of Child Welfare Law in 2003, the regional centers for children have been a part of the child welfare system, providing child-care services for families in poverty. In Korea, the regional centers for children were established during the poverty movement in the 1970s and have been developed as childcare providers for poor children since the financial crisis. However, the identity of regional centers for children is being threatened as the universal perspective on caring and the public values of caring services are being strengthened. There has raised a controversy around the role of regional centers for children that provide child-care services for vulnerable families. In addition, the survival of the regional centers for children is being threatened due to some issues regarding the content of their program as it is similar to those of other child-care agencies, the lack of cooperation among the ministries of government addressing public needs for child-care services, the poor working conditions of center employees, and the poor quality of services. The purpose of this study is to examine the formation process of the regional centers for children. After that, we discuss the current issues of the regional centers for children and seek alternatives that can settle the problems and respond properly to social changes.