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.

비용편익분석기법을 이용한 최적 낙석방지공법 평가 연구

박태순,노순미 서울産業大學校 2005 논문집 Vol.54 No.2

This study applied the cost-benefit theory in order to evaluate the financial reasonability of several methods relevant to the rockfall mitigation. The railroad line for the financial analysis is four lines having risks of rockfall, which are Young-dong line, Jung-sun line, Tae-baek line, and Joong-ang line. The significant conditions of study are 20m' section about each line based on the rockfall energy from 50kJ to lOOOkJ. This study has carried out the economical analysis such as Benefit-Cost Ratio(B/C), Net Present Value(NPV)', and Internal Rate of Return (IRR) through above mentioned conditions when various methods of the rockfall prevention including fences, walls, tunnels, and ring nets were constructed. As a result, this result shows what is the most efficient way in the aspects of economical efficiency. 본 연구는 낙석 저감에 관련된 여러 방법에서 경제적 합리성을 평가하기 위해 비용-편익 이론을 적용하였다. 경제성 분석을 위한 철도노선은 영동성, 정선선, 태백선, 중앙선으로 낙석의 위험을 갖고 있는 4개의 노선을 대상으로 하였다. 연구를 위한 중요한 조건은 50KJ에서 1000KJ의 낙석에너지를 갖고 있으며, 각 노선의 20m구간을 적용하였다. 낙석방지책, 낙석방지 옹벽, 피암터널과 링네트공법 등의 다양한 낙석방지공법이 실행될 때, 위에서 언급한 조건을 통해 편익-비용비(B/C), 순현재가치(NPV), 내부할인율(IRR)과 같은 경제성 분석을 수행하였다. 본 연구는 경제적인 효율성 측면에서 어떤 공법이 가장 효율적인 공법인지를 보여준다.

특집 : 고전기사와 일상성(日常性)의 문제 ; 기조발표 : 공시적 관점에서 본 고전시가와 일상성의 문제

양태순 ( Tae Soon Yang ) 한국시가학회 2010 韓國 詩歌硏究 Vol.29 No.-

일상성에 내포된 의미를 가운데 현대라는 시간, 산업사회에서의 도시라는 공간, 진정한 삶을 위해서는 벗어나야 할 굴레라는 부정적인 인식 등은 근대 이전 우리 선인들의 일상과는 무관한 것으로 보인다. 그러나 그 이외의 의미를, 예컨대 하이데거가 말한 잡담·호기 심·애매함이 현대 일상성의 존재양식이라는 것, 레비나스가 말한 향유를 통한 일상적 주체의 확립, 르페브르가 말한 현대의 일상성은 양식이 부재한 소비와 광고의 사회를 특징으로 한다는 것 등은 고전시가에도 적용될 수 있을 것이다. 하이데거에 의하면 우리들의 일상적인 삶의 존재양식은 잡담과 호기심, 그리고 애매함으로 표현된다는 점은 고전시가 〈쌍화점>, <사룡>, <사룡〉류의 시조들에서 확인되었다. 레비나스가 일상성의 토대라고 한 집이라는 거주공간이, 송순의 시조와 오규원의 현대시에서는 자연과 분리 단절된 공간이 아니라 함께 하는 공간으로 표현되었다. 요컨대 그들의 작품에서 자연세계는 소유물화되지 않았던 것이다. 양식이 부재한 현대의 일상성은 소비와 광고의 사회라는 르페브르의 진술을 바탕으로 고전시가인 〈한림별곡〉과 함민복의 현대시 〈광고의 나라〉를 대비시켜 본 결과, 전자의 경우 당대인의 삶과 문학작품에 형식과 주제의 양면에 걸쳐 양식이 있었는데 반해, 후자의 경우 그것이 부재함을 확인하였다. 본 연구를 통해 현대의 일상성이라는 개념을 가지고도 고전시가를 보다 정밀하게 분석 할 수 있음을, 그리고 일상성의 개념에 기댈 때 고전시가와 현대시 사이에도 공통점이 발견된다는 점을 확인할 수 있었다. 요컨대 일상성의 측면에서 보더라도 고전시가는 현대시의 토대가 되고 있음이 검증되었다고 하겠다. Some meanings of dailiness such as the modern times, the city town places of industrial society, the negative recognition that we have to get rid of the dailiness for our true life have nothing to do with Korean predecessors. But the others such as chitchat, curiosity, obscurity which were referred to as the being mode of dailiness by M. Heidegger and establishment of subjectivity through possession which was referred by Emmanuel Lvinas and the absence of style in modern dailiness which was referred to as characteristic of the society of consumption and advertisement by Henri Lefebvre will be applied to the Korean old poetry. Chitchat, curiosity, obscurity which were referred to as the being mode of dailiness by M. Heidegger were certified in the Korean old poetry <Ssanghwajeom> <Saryong> <Saryongryu Sijo> A house which Emmanuel Lvinas referred to as the foundation of dailiness was not the place cut off from natural world but the place connected with it in Song Soon`s old poetry Sijo and Ohgyuwon`s modern poetry. In the final analysis, the natural world in their works did not come into their possession. Both old poetry <Hanlimbyeolgok> and Ham minbok`s modern poetry represented the characteristic of the society of consumption and advertisement, but the former involve style of the form and theme, on the other hand the latter didn`t.

재무정보의 유용성 추세에 관한 사례연구

이장순(Jang-Soon Lee),문태형(Tae-Hyoung Mun) 한국무역연구원 2022 무역연구 Vol.18 No.6

Purpose – This study compares the financial statements of major Korean and US companies in order to solve the limitations of drawing conclusions only through inferences through statistical analysis without drawing conclusions from previous studies by Mun Tae-hyoung and Lee Jang-soon (2018). Design/Methodology/Approach – For companies listed on the Korean stock market, in order to confirm the correlation between net income, net asset value, and the market capitalization of financial statements, first, the growth rate of the Korean KOSPI and the US DJGI was compared, and then similar indicators of representative companies are compared. Findings – As a result of comparison, the profitability of similar companies in the US was higher than that of Korean companies, and it was possible to verify that this was caused by the fact that US companies had higher profitability than Korean companies in previous studies. However, in the comparison of total capital and tangible and intangible assets, some obtained the same results as the inferences of previous studies, but some showed results that did not match such inferences. Research Implications – Lev & Gu (2016), in their book “The End of Accounting and the Path Forward for Investors and Managers”, suggest that intangible assets, the most important assets in modern companies, are not shown in financial statements as one of the reasons for the end of accounting. This study confirms the claim that it is not. To this end, it is thought that the meaning of this study can be given by examining the differences in the accounting methods between Korea and the United States.

한국산 약용식물의 화장품천연소재로서 응용에 관한연구

안봉전,이진태,이순애,곽재훈,박정미,이진영,박태순,손준호 경산대학교 생명자원개발연구소 2003 생명자원과 산업 Vol.7 No.-

Biological activities and application of sanguisorbae officinalis L. were investigated. In the enzymological physiological activities, the electron donating ability(EDA) was 54.92% in 10 ppm and it was over 90% over 50ppm and SOD-like activity was high as 65.36% in 1000 ppm, it was gradual increased. As inhibitory effect of xanthine oxidase, it was 17.90% in 200 ppm and a little low as 36.89% in 500 ppm and inhibitory effect of tyrosinase, it was a little low as 20.45% below 1000 ppm. As the result of measuring the lipid oxidation, all the concentrations of medical ion treatments had the ability to keep it from acidification and metal ion blocking effects about the lipid oxidation promoting factors(Fe^(2+) and Cu^(2+)), Fe^(2+) was better than Cu^(2+) and all concentrations of medical ion treatments was 40% in 50ppm. When it was applied into normal skin-softener it showed safe effect so that we can expect that as the natural material of cosmetics.

위절제술 환자의 표준진료지침 개발 및 적용 효과

김은희,김철규,이순교,김순덕,이혜옥,권정순,이경미,이민미,심순미,유용만,신종식,강은희,이상일,김병식,오성태,육정환,박수길 한국의료QA학회 2003 한국의료질향상학회지 Vol.10 No.2

Background : Gastric cancer is the most common malignant tumor in Korea. surgical operation is one of the major treatment modalities for gastric cancer patients. Therefore, gastrectomy is one of the most common procedures in General Surgery. There were variation in length of hospital stay and medical treatment for gastrectomy between three surgeons at Asan Medical Center. Clinical pathways have received considerable attention as a tool for recucing the medical practice variation, increasing the efficiency of care process, and improving the quality of care. The aim of this study was to evaluate the effect of a clinical pathway for gastrectomy in gastric cancer patients. Methods : The clinical pathway for gastrectomy was developed and implemented by a multidisciplinary group in Asan Medical Center. A computerized clinical pathway program was developed and revised after a pilot test. A total of 145 patients underwent gastrectomy by three surgeons at Asan Medical Center. We compared the length of hospital stay, patient satisfaction, and unplanned readmission rate between the pre-pathway group(n=67) and the post-pathway group(n=78). We also investigated the degree of satisfaction among the physicians and nurses who were main end-users of the clinical pathway. Results : The clinical pathway was applied to all target patients. The average length of hospital stay was shortened from 12.7days to 10.6days(p<0.01). The degree of patient satisfaction with the care process changed from 90.3% to 89.2% after the implementation of the clinical pathway, but the difference was of satistically significant(p=0.761). Unplanned readmission rate was 2.9% in the pre-pathway group. More than 90% of physicians and nurses answered that the clinical pathway had been a useful tool in their medical practice. Conclusions : The findings of the study demonstrated that implementation of the clinical pathway for gastrectomy produced substantial reduction in the length of hospital stay while improving the quality of patient outcomes. The computerized clinical pathway program can be used as one of the powerful patient management tools for reducing the practice variations and increasing the efficiency of care process in Korea hospital settings.

IEEE 802.11기반의 애드 혹 네트워크의 효율적인 공간적 재사용에 관한 연구

김태경,홍순필,김은성 순천향대학교 산업기술연구소 2006 순천향 산업기술연구소논문집 Vol.12 No.1

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소아청소년기에 치수치료를 받은 제1대구치의 술전 상태 조사

이순영,이경호,노홍석,정태성,김신 大韓小兒齒科學會 2011 大韓小兒齒科學會誌 Vol.38 No.4

제1대구치는 막중한 역할을 함에도 불구하고, 청소년 이전에 건강을 상실하는 경우가 드물지 않다. 본 연구는 청소년기 이 전에 치수치료를 받게 된 제1대구치의 우식 및 수복 상태와 분포를 파악할 목적으로 시도되었다. 최근 5년간 부산대학교 치 과병원에서 치수치료를 받은 18세 이하 106명 환자의 135개 제1대구치를 대상으로 의무기록에 대한 조사를 시행하여 다음 과 같은 결과를 얻었다. 1. 평균 연령은 11.9세(남 11.5세, 여 12.5세)였고 유의한 성차를 보였으며(p<0.05), 악별로는 상악 47개, 하악 88개로 하악 치아가 더 많았다. 2. 치수 치료 전 치료 기왕력이 없는 치아는 74개, 치수 또는 수복 치료를 받은 치아는 61개였다. 그 중 재치수치료를 받게 된 경우는 22개로 치수절제술-치수절단술의 순이었으며, 단순 수복치료를 받았던 치아는 39개로 복합레진-아말감-GI- 인레이-수복물 탈락 후 미치료-열구전색 및 주조 전장관의 순이었다. 3. 병소 위치가 분류 가능한 73개의 병소 중에서는 근심면 병소가 22개, 교합면 혹은 협설면 병소 39개, 원심면 병소가 12 개를 차지하였다. In clinical dentistry, it is not difficult to meet the permanent first molars with severe coronal caries lesions in children or adolescents. The circumstances surrounding the first molars of children and adolescents are so immature and imperfect compared with those of adults. So we thought it significant to understand the status of these teeth at the moment of endodontic treatment and immediate cause of it. 106 patients with 135 permanent molars necessitating endodontic treatment in childhood and adolescence were included in this study, and the dental records and radiographs were examined. 1. The mean age was 11.9 year (male 11.5, female 12.5) and the result shows significant difference between gender(p<0.05). The mandibular teeth took more than half percentage than maxillary teeth. 2. Of 135 teeth, 45.2 percent of teeth had history of dental treatment previously and 16.3 percent of teeth showed necessity of re-endodontic treatment. 3. Of 73 teeth, 22 teeth had mesial-wall cavity causing endodontic treatment, 39 had occlusal cavity, and 12 had distal cavity.

고온에 노출된 콘크리트 미세조직의 특성

태순호,이병곤 社團法人 韓國火災 ·消防學會 1998 한국화재소방학회논문지 Vol.12 No.4

고온에 노출된 콘크리트 미세조직의 변화가 강도에 미치는 영향을 규명하기 위하여 현재 건설현장에서 가장 많이 이용하고 있는 배합비와 쇄석으로 시험체를 제작하여 고온에 노출시킨 후 SEM/EDX, XRD 및 DSC-TG로 분석하여 각 온도별로 강도와 미세조직 특성을 분석하였다. Very often, whether accidentally or intentionally set fire, according as building are elevated, varied or complicated day by day. It is of primary importance that we have a treatment of fire damaged structure. In general, strength and elasticity modulus of heated concrete are reduced. Product background of cement, sand and coarse aggregate differ from country to country, so that thermal behaviour of concrete make a difference in high temperature. To cope with demand, this paper is a study on relation to microstructure and strength reduction. In consequence of experiments, concrete exposed to high temperature are estimating the reduction of mechanical properties in comparison with microstructure characteristics which are abtained from the SEM/EDX, XRD and DSC-TG analysis of heated specimens under various temperature.

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