Method for Protection of Single‑Line‑Ground Fault of Distribution System with DG Using Distance Relay and Directional Relay

Jung‑Hun Lee,Min‑Su Park,Hong‑Seon Ahn,Kyung‑Won Park,Jun‑Seok Oh,Seung‑Gyu Jeon,Dong‑Kyu Kim,Jae‑Eon Kim 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.4

When large scales DG are connected to the distribution system of unidirectional power currents, bi-directional power currents are formed, making it impossible to use conventional overcurrent protection methods alone to detect and isolate fault sections for ground and short-circuit faults. To solve these problems, this study proposed the method of protection against single-line-ground fault of common neutral line multi-contact local power distribution system using distance relay and directional relay. The proposed protection method was applied to the common neutral multi-ground distribution system to validate the protection against single-line-ground fault through the PSCAD/EMTDC software package and efectively detect and isolate only the zone of single-line-ground fault without malfunctions.

3-Trolley Portainer Crane 운전 시뮬레이터의 개발

정민포,김규년,정태동,최제헌,김종훈 울산대학교 1994 공학연구논문집 Vol.25 No.2

항만에서, 빠른 시간내에 많은 양의 컨테이너 박스를 운반하는것이 곧 비용 절감이다. 이를 위해서는 크레인의 성능을 미리 예측을 할 수 있어야 한다. 특히 새로운 크레인을 제작할때, 실제 시험을 해본후 그 성능을 알아내기란 어려운 실정이다. 따라서, 컴퓨터상에서 이를 미리 시뮬레이션하여 그 성능을 알아낸다면 여러면에서 비용절감의 효과를 얻을수 있다. 본 연구에서는 기존의 하나의 Trolley에 의해 운전되는 크레인보다 더 나은 성능을 위해 설계된 3-Trolly Portainer Crane을 시뮬레이션하는 소프트웨어를 개발했다. 이것은 3개의 Torolley가 동시에 작동하여 하나일때보다 더 빠른 시간에 작업을 완수할수가 있다. 이 사실을 시뮬레이션을 통해 증명하고, 다양한 결과 자료를 이용해서 실제 이 크레인의 제작에도 상당히 도움이 될수 있다. 또한, 3개가 동시에 움직여서 각 구간별 소요시간의 측정이 문제가 되지만, 이것을 하나의 task로 미리 계산할 수 있는 방법을 고안, 적용하여 완수 하였다. In the port, it is a reduction of cost to load or unload many containers quickly. To do so, we should predict the performance of crane. Therefore, if we could simulate a crane operation and estimate the performance by the computer system, we can obtain a benefit of cost. In this study, we developed an operation simulator system of the 3-Trolley Portainer Crane which is designed for more efficeincy. Conceptually, the 3-Trolley Portainer Crane is operated concurrently by 3 trolleys, so it is faster than 1-Trolley Portainer Crane. We proved that through the simulation. It will be useful to manufactrue 3-Trolley Portainer Crane with many results from this software system. Also, the problem that must be calculated in parallel is solved by a single calculation method which we developed.

고효율 폐페인트의 재활용 기술 개발

정재헌,김정수,김종민,김영한,이상록,장상목 동아대학교 공과대학부설 생산기술연구소 1997 生産技術硏究所硏究論文集 Vol.2 No.1

In this study, the equipment and method to recyle waste-paint, were developed and investigated. The efficiency of drying and pulverizing the waste-paint were improved via vescosity reducing process and microwave energy source with a blast of hot air. This method may be useful to recyle the waste-paint, rubber and plastics.

정신분열병 환자의 인지과제수행에서 삼차원적 시공간-운동 방해자극 처리의 특성

정혜정,김재진,박성혁,전종희,김지혜,염태호,이장한,김선일,구정훈,조원근,안석균,이홍식 大韓神經精神醫學會 2003 신경정신의학 Vol.42 No.2

Objectives : Abnormalities of cognitive responses to verbal and visual distracter in schizophrenia have been demonstrated in numerous studies but little is known about three dimensional visuospatial-motor distracter processing. The purpose of this study was to investigate the vulnerability of patients with schizophrenia to three dimensional visuospatial-motor distracter. Methods : 14 patients with schizophrenia and 14 normal volunteers were assessed on three dimensional maze tasks requiring on working memory and reasoning ability in the virtual reality environment. Performances were compared according to with- or without-distracter conditions. Results : Patients with schizophrenia showed significantly lower performances than normal control group on cognitive flexibility, simple motor function or motor control and motor coordination, working memory span and delayed performance times. The performance index tended to be more deteriorated, but not significantly, in with-distracter condition than in Without-distracter condition in schizophrenia. Conclusions : Patients with schizophrenia tend to be vulnerable to visuospatial-motor distracter which simulate the real world of three dimensional environment.

수입각증후군에 의한 급성 복증 1례

정은욱,지삼룡,이영태,박지훈,김동기,제인수,채두근,박성재,박은택,이연재,이상혁,설상영,정정명 白中央醫療院 2005 仁濟醫學 Vol.26 No.1

Afferent loop syndrome is an uncommon complication of a gastrectomy and Billroth Ⅱ reconstruction. It may cause symtoms at any time from the first postoperative day to many years after the gastrectomy. Afferent loop syndrome is characterized by abdominal pain, vomiting and elevation of serum amylase. Thus, it is difficult to differentiate afferent loop syndrome from other cause of acute pancreatitis. However, the history of gastrectomy can be an important clue for diagnosing afferent loop syndrome. We experienced one case of chronic afferent loop syndrome with acute pancreatitis. After appropriate management, the abdominal pain disappeared and serum amylase level decreased. We report this case with a review of relevant literatures.

우라늄 이온의 선택흡착

정종헌,김준수,오원진,유재형,유승곤 한국공업화학회 2002 응용화학 Vol.6 No.1

Uranium-containing aqueous wastes have been treated by electrosorption on a carbon electrode composed of activated carbon fibers(ACFs) in a continuous flow-through cell. Effective uranium (VI) removal is accomplished when a negative potential in the range of -0.3 to -0.9V (vs. Ag/AgCI) is applied to the carbon electrode. For a feed concentration of 350mg/l, the concentration of U(VI) in the cell effluent is reduced to less than lmg/l. Electrosorption capacity over 552 mg_uranium/g_ACF is reached.

여가레크리에이션 프로그램 참여자의 몰입수준과 생활만족도 분석

정훈,남재화 龍仁大學校 體育科學硏究所 2005 體育科學硏究論叢 Vol.15 No.1

The purpose of this study is to clarify the commitment level and Life satisfaction of leisure-recreation program participants. To accomplish the purpose of this study, the adults over twenty years old were established as population and the 242 subjects who participate in leisure-recreation program operated in Korea were selected by the stratified cluster random sampling method. The survey questionnaires were used to collect data. To verify about Commitment Level, we applied the survey questionnaires developed by Scanlan(1993) and standardized by Jung Yong-gak(1996). To verify about satisfaction, we applied the survey questionnaires developed by Dinner, Emmonson, Larsen and Griffin(1985) and translated by Lee Jong-gil(1992). Within a certain period of the inquiry formality leisure-recreation program participants made out survey questionnaires as self-administration method. The statistical methods utilized in this study for analyzing the collected data were reliability analysis, descriptive statistics, standard multiple regression analysis. From the analysis of this study, the following conclusions were obtained: Firstly, leisure-recreation program participants's participation level partially influence on commitment level. Secondly, leisure-recreation program participants's participation period partially influence on life satisfaction. Thirdly, leisure-recreation program participants's commitment level is correlated to life satisfaction.

저전압/고용량 DRAM 회로를 위한 Half-VDD 전압 발생기 설계

이재형,우엄찬,박무훈,최중경,하판봉,김영희 국립7개대학공동논문집간행위원회 2005 공업기술연구 Vol.5 No.-

A half-VDD voltage generator(VHDD) using PMOS pull-up and NMOS pull-down transistors, and each of the gate voltage is able to swing at CMOS voltage level was newly proposed. Designed with these, pull-up current was made to be proportional to (VDD-|V_(TP)|)^2 and pull-down current was made to be proportional to (VDD-|V_(TN)|)^2. Also, being turned on pull-up and pull-down transistors at the same time was prevented by using short-circuit current protection circuit. Test chips which were designed by using 0.35μm CMOS twin-well process technology were fabricated and the result of measurement was suitable for low-boltage DRAMs.

혈관과증식을 동반한 구개부 선방세포암의 치험례

김상중,심재환,박정훈,이원학,이정구 대한악안면성형재건외과학회 2000 Maxillofacial Plastic Reconstructive Surgery Vol.22 No.6

Vascular lesions of the oral and maxillofacial area is interesting to clinicians because it is difficult in management and has poor prognosis. There have been attempt to classify vascular lesion and recently new classification is introduced that have two basic entities, 1) hemangioma, 2) vascular malformation. It is useful that evaluation of lesion, treatment planning and predicting on prognosis. But vascular lesion is still difficult to clinicians about treatment. A case of acidic cell carcinoma combined with hypervascularity arising on the hard palate in a 28-year-old woman is reported. We mistook it for vascular lesion because of hypervascularity. The clinical and histologic feature are described. Literatures about neovascularization of tumor & acidic cell carcinoma are reviewd, too. And we attempt to solve the problem of hypervascularity.

청소년의 스포츠 활동유형과 대인관계 성향의 관계

김재현,박정훈 한국학교체육학회 2001 한국학교 체육학회지 Vol.11 No.1

본 연구에서는 청소년의 스포츠 활동유형과 대인관계 성향이 어떤 관계가 있는지를 분석하고자 하였다. 연구의 대상은 2001년 현재 서울, 경기도 지역에 재학중인 중학교 청소년으로서 스포츠 활동 청소년을 모집단으로 설정한 다음 유충 집락 무선 표집법(stratified cluster random sampling)을 이용하여 표본을 추출하였다 본 연구에서 표집한 유효 표본 수는 총 116명이었으나 실제 분석에 사용된 자료 중 불성실하게 응답한 자료로 판단되거나 조사내용의 일부가 누락된 24명의 설문지를 제외한 92명의 자료를 분석하었었다. 자료분석을 위하여 본 연구에서 사용한 통계분석기법은 조사대상의 일반적 특성을 알아보기 위하여 기술통계를 실시하였고, 스포츠 활동유형과 대인관계 성향의 차이를 알아보기 위하여 공변량 분석과 중분류 분석을 실시하였다. 이와 같은 자료수집, 분석과정 및 논의를 통하여 얻어진 본 연구의 결론은 다음과 같다. 스포츠 활동유형과 대인관계 성향의 하위요인 중 사회 관계성향에서 개인 스포츠 활동 청소년이 단체 스포츠 활동 청소년에 비하여 높게 나타났으나, 역할성향 및 표현성향에서는 유의한 차이가 없었다. The purpose of this study was to investigate the relationship between the type of youth's sports activity and interpersonal-related disposition and to provide a basis for the development of personality education policy about youth. The researcher sampled 92 students middle schools in Seoul and Kyonggi province. The data collected from the questionnaires were conducted by statistical analysis methods such as multiple classification analysis, ANOVA correlation analysis and multiple regression analysis. The conclusions of this study, verifying the hypotheses about the relationships between the type of youth's spore activity and interpersonal-related disposition were as follows; The youths who play personal sports activity were higher than the youths who play group sports activity in the social relationship propensity out of the subordinate of interpersonal-related disposition but there was no difference in role propensity and expression propensity.