Study on Reliability Improvement of Voltage Transformers by Increasing Voltage Factor

Tae‑Sik Kong,Hee‑Dong Kim,Hung‑Sok Park,Soo‑Hoh Lee,Soon‑Yong Kim,Pil‑Bum Joung,Jin‑Yeub Park 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.3

Voltage transformers (VTs) must be highly reliable as they are essential components of the electric power industry. VT failures can cause a signifcant impact for important facilities such as nuclear power plants. In fact, VTs which passed the international standard, were damaged and sometimes resulted in the shutdown of the nuclear power plants. In order to improve the reliability, VTs with various iron core was studied. The electromagnetic feld simulation, a saturation characteristics test, and an overvoltage breakdown test were conducted. The result shows that the magnetic fux density signifcantly afects the reliability of VTs. To increase the reliability of VTs, it is required to reduce the magnetic fux density by increasing the knee-point and voltage factor. Owing to limited installation space, increasing the size of the iron core is difcult. Instead, VT by decreasing the thickness of the conductor and increasing the number of turns, it was possible to reduce the magnetic fux density without the size change. Therefore, improved VTs were obtained by decreasing the thickness of the conductor and increasing the number of turns, and the improved reliability was verifed through a comparison test with existing VTs. The fabricated VTs shows a signifcantly higher saturation voltage and breakdown time than existing VTs. Thus, by proposed VTs can contribute the stable operation of the nuclear power plant and improve the manufacturer’s quality.

춘천지역 도시열섬의 특성과 대기질에 미치는 영향

이종범,김용국,김태우 江原大學校 附設 環境硏究所 1994 環境硏究 Vol.11 No.-

An observational study of urban heat is1and was carried out using field data obtained during 6 day in May and August 1992 in Chunchon(Population size 180,000). Air temperature was measured at 04 points along two sampling routes by thermisters attached to cars, Both routes cover urban and rural area and across the center of urban area, Continuous observation of air sonde was performed to clarify heights of nocturnal boundary layer(NBL) at the center of urban area. Surface meteorological observations were performed at both urban and rural site. This study showed that heat island Phenomena was obvious1y observed at the urbanized area during the night time With low wind Speed. The average NBL heights extended to about 100 meters, but varied with meteorological conditions. After sunset the air temperature decreased with time at both sites and cooling rate at the urban site was Heater than the rural site. The maximum heat island intensity was 7.5°C at 21 LST May 4. Using the two meteorological data gets obtained from urban and rural sites, the air Pollutant concentration was calculated by Gaussian plume model which can obtain not only horizontal distribution of concentration but also vertical distribution. The result indicated that the concentration resulted from urban meteorological data set was lower than that from rural meteorological data set. It was also calculated that the air pollutant extended to higher level in urban meteorological data set than that in rural meteorological data set.

Micrococcineae에 속하는 식물 연관 방선균

김태수,한지혜,김승범 충남대학교 생물공학연구소 2012 생물공학연구지 Vol.18 No.-

공동주택 유지관리 FCI 모니터링에 관한 연구

범성우,정영한,박태근 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1

After the 1980' s governmental housing business policy was vigorously attained, demand of apartment housing is still on the increase, but systematic maintenance is not following this current incerase trend. A promotion about the realization on the importance of maintenance due to life-time degradation of apartment housing and a plan of life-long practice of maintenance established together with longterm stratergy for maintance upkeep must be imperative. Purpose of this study presents application plan about FCI from rifle cycle viewpoint of building. Expect that is used laying plan that is middle part of a song miracle in actuality and expense arbor in the mountains of longtimer line plan of apartment house. As administration subject establishes well-timed repair time and more strategic budget, may behave better maintenance.

편측안면경련에 대한 미세혈관압술시 수술시야 확보를 위한 방법으로서 소뇌피질동맥 박리술 - 수 술 수 기 -

김범태,임수빈,장재칠,신윈한,최순관,변박장 대한신경외과학회 1998 Journal of Korean neurosurgical society Vol.27 No.11

서울·경기지역 일식체인 레스토랑의 선택속성에 관한 연구

윤태환,이수범,윤혜현 한국식생활문화학회 2004 韓國食生活文化學會誌 Vol.19 No.1

The specific purposes of this study are that ; 1) to investigate the distinguished selection attributes on performance of Japanese chain restaurant according to general characteristics of the respondent ; 2) to find out relationships between selection attributes on performance for Japanese restaurant and customer's satisfaction. Frequency analysis, one-way ANOVA, reliability analysis, factor analysis, multiple regression were used to analyze the data. Total 350 questionnaires were distributed and 312 were replied(89.14%). Selection attributes on performance for Japanese chain restaurant was divided into 7 factors. There are Factor1 "Store Image & Kindness", Factor2 "Sanitation & Taste", Factor3 "Approximation & Children's Menu", Factor4 "Delivery & Business Hours", Factor5 "Food Quantity & Korean Food", Factor6 "Service & Parking", Factor7 "Price & Publicity", Monthly income, eating-out expense per once and type of companion have significant influences on selection attributes for performance. Customer's total satisfaction is significantly affected by selection attributes on performance. Factor7 "Price & Publicity" has the most significant influence on customer's satisfaction. We expect that the result can be used to provide basic information to plan marketing strategies, and take improved customer's satisfaction for Japanese chain restaurant.

동안신경 상분지만을 침범한 토로사-헌트 증후군 1예

성기범,이태경,박선아,안무영 대한평형의학회 2003 Research in Vestibular Science Vol.2 No.2

GIS와 항공정사사진을 이용한 산림정보 관리시스템 구축

김준범,조명희,권태호,김인호,조윤원,신동호 한국지리정보학회 2004 한국지리정보학회지 Vol.7 No.2

우리나라 산림행정 업무의 대부분은 서류 및 대장에 의존하고 있는 실정으로 신속, 정확하고 다양한 업무 처리를 위해서는 첨단의 공잔정보기술을 이용한 과학적인 산림정보 관리시스템의 개발이 시급하다. 특히 지리정보시스템(GIS)과 항공사진 활용기술의 도입은 산림이용기본계획이나 산지개발, 산림자원 관리 및 산림보호 정책 등의 의사결정지원에 효율적으로 기여할 수 있을 것이다. 본 연구에서는 GIS와 항공사진(1998년도 촬영)을 기반으로 주요 산림정보인 수치지도, 수치임상도, 임야도 및 관련 속성데이터 둥을 가공하여 DBMS(data base management system) 내에 저장하였으며, 이를 기반으로 세부 응용시스템인 지번별 임야정보 검색, 산지이용개발 정보관리, 법정제한림 정보관리, 산림자원 정보검색 등의 인터페이스를 개발함으로써 산림 관련 실무자가 산림정보의 종합적인 공간분석 및 질의 검색이 가능한 산림정보 관리시스템을 구축하였다. 본 시스템의 구축으로 산림의 효율적 관리는 물론, 경제적인 산림자원 및 임산업 육성과 쾌적한 산림환경을 조성할 수 있을 뿐만 아니라 관련 부서들 간의 표준화된 공간 자료 공유와 과학적인 정보체계의 연동으로 산림자원 관리를 위한 집약된 공간 및 전자 정보화 인프라 구축의 기반을 마련할 것으로 사료된다. Recently in order to more effectively and scientifically process forest official tasks, which have been focused on documents and inventories, they should be applied with the up-to-date spatial information technologies. Especially, the forest resource information management based on GIS (geographic information system) and aerial orthophoto is expected not only to play an important role as DSS (decision support system) for domestic forest conservation policy and forestry development industry but also to service forest resource information toward people such as the owners of a mountain rapidly. In this study, the important forest information such as digital topography map, digital forest type map, digital forest cadastral map, digital aerial photographs and attribute data were first reprocessed and constructed in DBMS (data base management system). In addition, forest officials could analyze and retrieve forest information by using detail sub-application systems such as forest cadastral retrieval, forest land development information management, reserved forest information management and forest resource information retrieval. For this, the user interface is developed by using Visual Basic 6.0 and MapObjects 2. 1 of ESRI based on CBD (component based development) technology. The result of developing this system will not only perform constructing economical forest and better environment but also be the foundation of domestic spatial technology for forest resource management.

PC를 이용한 소아과 퇴원환자 관리시스템

하태선,이태수,차은종,박범수,한헌석,채수일 충북대학교 의과대학 충북대학교 의학연구소 1993 忠北醫大學術誌 Vol.3 No.1

본원 소아과 입원환자의 퇴원요약 기록을 전산관리하는 시스템을 개발하였다. 소아과 환자관리에 적합하도록 퇴원요약지를 설계하였고 개인용 컴퓨터를 사용하여 관리하도록 구성하였다. 주 기억장치 4MB와 보조기억 장치 120MB HDD을 장착한 PC-386DX 시스템을 기반으로 개발하였고 소프트웨어로는 FoxPro v2.0을 사용하였다. pull-down menu 방식과 window방식을 적용하여 비전문가라 할지라도 손쉽게 사용할수 있도록 하였고 정보입력 및 수정시 사용자 편의를 최대한 반영하고자 하였다. "AND"와 "OR"연산자를 사용하여 다양한 검색이 가능하였다. 본 시스템은 현재 본원 소아과에서 실무에 적용하고 있으며 향후 통계분석과 임상연구에 크게 활용할 수 있으리라 생각된다. A PC-based system was developded to manage discharge summary records of pediatric patients. It is based on a PC-386DX system equipped with 4MB memory and 120MB HDD, and its software was written in FOXPRO V2.0. Any users unfamiliar with computer can make an easy access to the data through pull-down menu and windows system. Logical operators of "AND" and/or "OR" enabled a flexible and various search conditions. The present system is being under clinical use in the Department of Pediatrics, and warrants future applications to statistical analysis as well as clinical research projects.

금합금의 프라이머 처리가 교정용 브라켓의 접착에 미치는 영향

류동범,권태엽,권용훈,김교한 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.3

The purpose of this study was to compare the bonding strength and the interfacial micromorphology of two surface modification of gold alloys in direct bonding of orthodontic brackets. Flat tab of cast gold alloys (n= 120) were subjected to either of two surface treatments: 1.50㎛ aluminum oxide sandblasting, and 2. sandblasting plus adhesive primer for noble metal. Orthodontic brackets (RMO Co.) were bonded directly with Superbond C&B (Sun Medical Co. Ltd.), or Transbond XT (3M Unitek), or Ortho One (Bisco). All specimens were stored in distilled water at 37℃ for 24 hours, and then the tensile bond strength testing was performed in a Instron test machine. Bond failure sites were classified by a modified Adhesive Remnant Index (ARI) system. The results showed that sandblasting plus adhesive primer for noble metal produced stronger bonds to gold alloy than sandblasting only in all cases (Superbond C&B, Transbond XT, Ortho One). Superbond provided significantly stronger bonds to gold alloy than the others. Bond failure of Superbond to sandblast only and sandblast plus adhesive primer for noble metal to gold alloy occurred at the bracket/adhesives interface, whereas bond failure of the others occurred at the gold/adhesive interface. The clinical implications of these findings are discussed.