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.

Micrococcineae에 속하는 식물 연관 방선균

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

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.

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

隔板을 가진 水平環狀空間에서 自然對流에 관한 實驗的 硏究

鄭泰鉉,金善政,李範澈,權純錫 동아대학교 공과대학 부설 한국자원개발연구소 1988 硏究報告 Vol.12 No.2

Natural convection from a horizontal annulus with spacers has been studied on the effects of Rayleigh numbers and position of spacers by experimental method. In case of vertical spacers, the maximum local Nusselt number appears at θ=150° in a conducting tube and θ=30° in a cylinder. The local spacer Nusselt numbers show positive values on the lower spacer, but negative values on the upper spacer. In case of horizontal spacers, the flow over the spacer is more active than that of under the spacer as the Rayleigh number increase. The maximum local Nusselt number appears at θ=180° In a tube and at θ=0° in a cylinder. The local spacer Nusselt number show positive values on the upward surface of spacer, but negative values on the downward surface of spacer. The mean tube Nusselt numbers and mean cylinder Nusselt numbers with vertical spacer are increased 11% And 2.7%, respectively by those of horizontal spacer.

박복되는 현훈으로 발현한 보크트-고야나기-하라다 증후군 1예

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

수술의 함정 : 중심성 신경세포종 2례 2 Cases of Central Neurocytoma

김범태,주교성,장채칠,신원한,최순관,변박장 대한신경외과학회 1999 Journal of Korean neurosurgical society Vol.28 No.3

하악골에 발생한 골막 골육종

김태우,김승범,권혁찬,문선재,윤정훈,김형준,차인호,육종인,김진 대한악안면성형재건외과학회 2002 Maxillofacial Plastic Reconstructive Surgery Vol.24 No.1

Periosteal osteosarcoma is a distinct entity of malignant bone tumor with characteristic clinical, morphological, and histological features within the group of juxtacortical osteosarcoma. Periosteal osteosarcoma is predominantly located in the tubular long bones, and extremely rarely involving the jaws. A case of periosteal osteosarcoma of the right mandible is presented. A 27-year-old woman complained of the gingival swelling and bleeding tendency of the right posterior mandible. Clinical examination revealed a reddish brown strawberry-like swelling on the affected mucosa, which measured 1.5㎝×1.5㎝. The tumor was located on the lingual cortex of the mandible and extended into the surrounding soft tissues. Microscopically, the tumor consisted exclusively of atypical chondroblastic cells with a small osteoblastic area. A minimal bone marrow involvement was noted and the adjacent cortex was free of tumor. These findings suggested that the tumor originated from the periosteal cambium layer, which lies between the periosteal fibrous layer and the cortex of mandible.

忠北大學校 附設 平生體育硏究所

金泰完,金昌範,張鳳愚,金奎鎭 忠北大學校 平生體育硏究所 1985 平生體育硏究所 論文集 Vol.1 No.-

This study is based on the written inquiry about STAI as a measuring tool, which spielberger developed as a anxiety measure to examine what relationship is between the ability in athletic sports and anxiety. The female or male 153 players 918 to 21 years old) became the subject of this written inquire. Trait anxiety was measured by Form x-2 of STAI (State-Trait Anxiety Inventory) while state anxiety was measured by Form x-1. And then, we compared the records in everyday practices with those in games, and used these records as an ability in games. We tried to clarify the relationship between the ability in games and the anxiety. The subjects for the measurement is divided in the three groups of the athletics track sports; a short, a middle, a long-distance race, and the three groups of the athletics field sports; running, jumping and throw. Analysis-the correlation with the state-trait anxiety we measured the records of athletic sports, examined the influence that anxiety exerts on the ability in game, and compared and analyzed the level of anxiety in each event. We have received these results as the following. 1. The influence that anxiety exerts on the athletics records. The events of athletic sports the relation between the anxiety in everday life and the records in that time shows its correlation(r=-0.374, r=-0.361) only in 100m running, but this is not connected with the other events. But except the midium distance events all of the women and men players are connected with the relation detween the anxiety in game and the records. So, because the level of anxiety in the game affects the records in the game, the players need to practice the psychological control of themselves and a little anxiety is needed as a stimulant in everyday practices. 2. Anxiety and records in usual time and game. In events of athletic track sports there was a deep relation, except the event of women distance running (r=0.365), between the anxieties in normal times and in game; (0.50,r<0.70). And the event of men 100M running practicing records in normal times and those in games was not considered here. Therefore, the higher anxiety one has in normal times, the higher his anxiety tends to go up in games; the records in practicing times generally corespond to those in games though such relation is not always applied to the event of 100M running. 3. Anxiety in track and field athletic sports. There was no difference of anxiety in the events of track and field athletic sports between men and women players. Anxiety in games showed the difference in the mean value in all games and their players.