1×3행렬구조ㅡㄹ 갖는 매트릭스형 초전도 한류기의 자장유무에 따른 퀜치특성 분석

吳金坤(Kum-Gon Oh),趙鎔善(Yong-Sun Cho),崔孝祥(Hyo-Sang Choi) 대한전기학회 2008 전기학회논문지 P Vol.57 No.3

We investigated the quench characteristics accordance with increase of turns and applied voltage of matrix-type superconducting fault current limiter (SFCL) with 1×3 matrixes. The matrix-type SFCL consists of the trigger part to apply magnetic field and the current-limiting part to limit fault current. The fault current limiting characteristics according to the increase of magnetic field and applied voltage were nearly same. This is because the application of magnetic field hasnot an affect on total impedance of SFCL. When number of turns of reactor increased, the voltage difference between two superconducting units in the current-lirniting part according was decreased. The resistance difference generated in two superconducting units also was decreased. Therefore, we confirmed that the differences of critical behaviors between superconducting units by application of magnetic field were decreased. By this results, we could be decided the optimum number of turns of reactor to apply magnetic field.

매트릭스형 초전도 한류기의 임피던스에 따른 회복특성 분석

오금곤(Kum-Gon Oh),김덕구(duck-gu Kim),정병익(Byung-Ik Jung),조용선(Yong-Sun Cho),최효상(Hyo-Sang Choi) 한국조명·전기설비학회 2009 한국조명·전기설비학회 학술대회논문집 Vol.2009 No.10월

초전도 한류소자의 병렬연결에 따른 자속구속형 초전도 한류기의 특성 분석

吳金坤(Kum-Gon Oh),鄭柄益(Byung-Ik Jung),崔孝祥(Hyo-Sang Choi) 대한전기학회 2008 전기학회논문지 P Vol.57 No.2

We investigated the operating characteristics of the flux-lock type superconducting fault current limiter(SFCL) with the parallel connection between the primary and secondary windings which are connected with two superconducting units in series. The parallel connection for current level increase of the flux-lock type SFCL is necessary to apply the SFCL into the power system.[1-7] The resistance generated in superconducting units was dependent upon the winding direction of the primary and the secondary coils, which can reduce the power burden. The resistance of the superconducting elements in the subtractive polarity winding is higher than that of the additive polarity winding. The fault current limiting effect of the subtractive polarity winding is better than that of the additive polarity winding. From this results, we confirmed that the power capacity of the flux-lock type SFCL could be increased by the parallel connection of the superconducting units.

전력계통의 지락사고에 대한 매트릭스형 초전도 한류기의 동작특성

오금곤(Kum-Gon Oh),조용선(Yong-Sun Cho),최효상(Hyo-Sang Choi),오성보(Seong-Bo Oh),김덕구(Deog-Goo Kim) 한국조명·전기설비학회 2009 조명·전기설비학회논문지 Vol.23 No.10

전력 계통 내에서 발생하는 과도한 고장전류의 억제를 위한 가장 이상적인 방안은 초전도 한류기이다. 초전도 한류기의 전력계통 적용을 위해 본 논문에서는 전력계통 내에서 발생하는 1선, 2선, 3선 지락사고를 모의하여 매트릭스형 초전도 한류기의 동작 특성 및 소비전력을 분석하였다. 모든 지락사고에 대해 매트릭스형 초전도 한류기는 사고 초기에는 85[%] 이상, 1주기 이후에는 95[%] 이상 고장전류를 제한시킬 수 있다는 것을 확인하였다. 또한 초전도 소자간의 임계특성의 차이를 줄여줌으로써 소비전력이 균등해진다는 것을 확인하였다. It is very important for power stability to suppress the excessive fault current happened frequently in the real power grid. The superconducting fault current limiter (SFCL) is one of the most effective ways to reduce the fault current among the facilities developed so far. In this paper, we have investigated the operating characteristics of the power grid with the SFCL according to three types such as the single, double and triple line-to-ground faults. In addition, we analyzed the consumption power of the superconducting units based on the working data of the SFCL. We confirmed that the fault current could be limited lower than its peak value to 85 percentage in initial fault condition and to 95 percentage after one cycle in the matrix-type SFCL. The consumption powers of the superconducting units were almost equal by reduction of the difference of the critical current between superconducting units element.

學校周邊騷音에 대한 學生意識構造 조사 : 대구지역 고등학교 2학년을 대상으로

금경호,김복련,서양곤 경상대학교 환경보전연구소 2000 環境保全硏究所報 Vol.8 No.-

The purpose of this study was to investigate the students' consciousness against noise around nine high schools in Taegu City. It was carried out to make up and analyze a question of noise. The results are summarized as follows : 1. Two schools whose Leq was below 50㏈(A) showed comparatively little noise pollution from noise measurement of schools. Four schools, though their Leq was a little more than 50㏈(A), were supposed to have little complaint about noise because their TNI value was less than 50. Three schools was estimated to have extreme discontentment about noise because their Leq was more than 60㏈(A), so exceeded environmental standard value(50㏈(A)) and their TNI exceeded 70. 2. In questionaire, 61.2% of respondents answered that noise around school was very severe. The main sources of noise were street traffic(45.7%). In season the noise of summer was most severe(81.0%) The responsibility of noise was given to school(21.0%) and community(30.1%). The questionaire showed that damage to study was 56.2% in class, 24.8% in examination. The response to noise during class showed that most students studied bearing noise but 12.3% students gave up studying. About physical damage, 10% students answered 'a little severe' or 'severe', so physical damage was not serious. About mental damage, 30% students-answered 'a little severe' or 'severe', so three times large as the physical damage. As the result, today noise around school in Daegu cause great damage to students in school life, especially study and its psychological effect. Therefore, to live in a good sound environment the study of counterplans to noise around school must be continued.

Effects of Compatibilizer on Mechanical, Morphological, and Rheological Properties of Polypropylene/Poly(acrylonitrile-butadiene-styrene) Blends

Kum, Chong-K.,Sung, Yu-Taek,Kim, Yong-Su,Lee, Hyung-Gon,Kim, Woo-Nyon,Lee, Heon-Sang,Yoon, Ho-Gyu The Polymer Society of Korea 2007 Macromolecular Research Vol.15 No.4

The effects of a compatibilizer on polypropylene (PP)/poly(acrylonitrile-butadiene-styrene) (ABS) blends were studied. Blends of the PP/ABS, with PP-g-SAN copolymer as a compatibilizer, were prepared using a twin screw extruder. The flexural and impact strength of the PP/ABS blends with the PP-g-SAN copolymer increased significantly with PP-rich compositions on the addition of the PP-g-SAN copolymer at 3 phr. The increase in the mechanical properties of the PP/ABS/PP-g-SAN blend may have been due to the toughening effects of the ABS in the PP-rich compositions. In the morphology study of the PP/ABS/PP-g-SAN (80/20) blend with the PP-g-SAN copolymer, the minimum droplet size, $5.1{\mu}m$, was observed with the addition on phr of the PP-g-SAN copolymer. The complex viscosity of the PP/ABS/PP-g-SAN (80/20) blends increased with the addition of3 phr of the PP-g-SAN copolymer. From the above mechanical properties, morphology and complex viscosity results for the PP/ABS blends, it is suggested that the compatibility is more increased with the PP-rich composition (PP:ABS=80/20 wt%) of the PP/ABS blend on the addition of 3 phr of the PP-g-SAN copolymer.

비정질 Se/전극 A1 소자의 경일변화에 따른 광전특성

오금곤,임양수,김대곤 조선대학교 동력자원연구소 1993 動力資源硏究所誌 Vol.15 No.2

Photoconductive characteristics with aging variation in a-Se/Al sample had been investigated. When the samples were kept in air, their capacitance first decreased and then increased. But their photocurrent, photovoltage and dark EMF increased gradually with time. It was also observed the photocapacitance effect to verify trap formation. As the results, it was found that Al^+3 ion has ralated to be Se crystallization by migrating into a-Se and form trap in a-Se. According to he experimential result, structural change of the a-Se layer with time was confirmed by X-ray diffraction.

두개의 GIA 자동문합기를 이용한 Hirschsprung씨 질환의 근치술 3예

최금자,김원곤 梨花女子大學校 醫科大學 醫科學硏究所 1983 EMJ (Ewha medical journal) Vol.6 No.4

Hirschsprung's disease is a congenital abnormality characterized by chronic constipation secondary to the absence of myenteric parasympathetic nerve ganglia in the distal large intestine. The definitive operative treatment for Hirschsprung's disease is divided into three main classes- Swenson abdominal pull-through operation, Duhamel retrorectal pull-through operation, and Soave endo-rectal pull-through operation. But each of these technics has one or more frequent complications or operative difficultes. Recently, the gastrointestinal stapling device is employed to cut away the common wall between the rectum and pulled-through colon of the Duhamel procedure for Hirschsprung's disease. The authors performed three Duhamel procedures for Hirschsprungs disease using two GIA Autosutures at Ewha Womans University Hospital during recent several months, and are presenting with review of the world literatures.

환경에서의 오존이용 전망

김병호,금경호,서양곤 경상대학교 환경보전연구소 2001 環境保全硏究所報 Vol.9 No.-

Ozone was first used to disinfect water supplies in France in the early 1900s. Its use increased and eventually spread into several Western European countries. Today nearly 1,000 ozone disinfection installations exist (primarily in Europe), almost entirely for treating water supplies. A common use for ozone at these installations is to control taste-producing, odor-producing and color-producing agents. Ozone can also be used in wastewater treatment for odor control and in advanced wastewater treatment for the removal of soluble refractory organics, in lieu of the carbon-adsorption process. Ozone is also very effective virucide and is generally believed to be more effective than chlorine. Ozonation does not produce dissolved solids and is not affected by the ammonium ion or pH influent to the process. For these reasons, ozonation is considered a alternative to either chlorination of hypochlorination, especially where dechlorination may be required.

Identification of alpha-Gal and non-Gal epitopes in pig corneal endothelial cells and keratocytes by using mass spectrometry.

Kim, Yun-Gon,Oh, Joo Youn,Gil, Geun-Cheol,Kim, Mee Kum,Ko, Jung Hwa,Lee, Sukmook,Lee, Hyun Ju,Wee, Won Ryang,Kim, Byung-Gee IRL Press 2009 Current eye research Vol.34 No.10

<P>PURPOSE: To investigate the expression of alpha-Gal or unidentified non-Gal antigens in pig corneal endothelial cells and keratocytes, we performed the qualitative and quantitative analysis by using mass spectrometry. METHODS: The N-glycans from common adult pig corneal endothelial cells and keratocytes cultured in vitro were directly analyzed by using mass spectrometric approaches. In addition, immunochemical staining was added to confirm the non-Gal antigen expression in pig corneal cells. RESULTS: Totally, 34 of the sialylated N-glycans from pig corneal endothelial cells and 27 from pig keratocytes were identified and observed to contain nonhuman sialic acid, NeuGc as well as NeuAc. In addition, we were able to detect 25 of alpha-galactosylated N-glycan structures (22.2% of total) from the pig corneal endothelial cells and 18 of that (17.5% of total) from the pig keratocytes by using mass spectrometric approaches. On immunofluorescent staining, the expression of sialylated glycans was also observed. CONCLUSIONS: As well as alpha-Gal epitopes, several promising non-Gal antigens were widely expressed on both pig corneal endothelial cells and keratocytes. The detailed structural information of the alpha-Gal and non-Gal epitopes would be a tremendous value to develop a new strategy for the successful corneal xenotransplantation in future.</P>