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.

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.

천안지역 일부 다중이용시설의 포름알데히드 농도에 관한 연구

전혜리(Hye-li Jeon),조수연(Su-yeon Jo),조혜란(Hye-ran Jo),조태진(Tae-Jjn Cho),박종안(Jong-an Park),손부순(Bu-soon Son) 대한환경위생공학회 2009 대한환경위생공학회지 Vol.24 No.2

This study was conducted at a Terminal, a Parking Lot, an Underground shopping center, a Funeral hall and a Hospital waiting room of Cheon An area in August 2008 to examine the concentration level of HCHO(formaldehyde). The concentration level of the remodeled sites were 39.4 ± 12.0 ㎍/㎥ in the terminal, 32.7 ± 7.3 ㎍/㎥ in the parking, and 97.8 ± 29.4 ㎍/㎥ in the underground shopping center. The underground shopping center had the highest level and followed by the terminal and the parking. On the contrary, the site remodeling had the level of 17.7 ± 12.4 ㎍/㎥ in the funeral hall and 17.9 ± 0.6 ㎍/㎥ in the hospital waiting room. The funeral hall had highest level than that of the hospital waiting room. Both the remodeled sites and the not remodeled site had concentration level of HCHO below the standard level, but it was higher in the remodeled sites. There were no relations among the HCHO, the temperature and the humidity in facilities of Cheon An area.

법랑질 형성부전증 환아의 치험례

박희숙,김태완,김영진,김현정,남순현 大韓小兒齒科學會 2008 大韓小兒齒科學會誌 Vol.35 No.3

Amelogenesis imperfecta is a group of hereditary defects of enamel, unassociated with any other generalized defects. It is classified into 14 subtypes according to different clinical and genetic features. According to its clinical features, it is classified into hypoplastic type, hypocalcified type and hypomaturation type. However, these features tend to co-exist often. Dental features associated with amelogenesis imperfecta include quantitative and qualitative enamel deficiencies, pulpal calcification, root malformations, abnormal eruption, impaction of permanent teeth, progressive resorption of root and crown, congenital missing teeth and anterior and posterior open bite occlusions. The first case patient is a 16 month-old child with discoloration of deciduous teeth. All of her deciduous and permanent dentition has shown amelogenesis imperfecta. The restorational, orthodontic and recent prosthodontic treatments have been completed. Another patient is a 9 year and 3 month-old child with amelogenesis imperfects in both deciduous and permanent dentition. The restoration has been done and the prosthodontic treatment is planned after the completion of growth. Above cases indicate that amelogenesis imperfecta occurs both in deciduous and permanent dentition, and it requires the long term treatment and care. 법랑질 형성부전증(amelogenesis imperfecta)은 전신질환과 관련없이 법랑질에 결함을 나타내는 유전질환이다. 법랑질 형성부전증은 발현되는 증상과 유전 양상에 따라 14가지의 아류형으로 분류된다(Witkop, 1989). 임상적으로는 크게 형성부전형(hypoplastic type), 저석회화형(hypocalcified type), 성숙부전형(hypomaturation type)으로 나누어진다. 하지만 이들은 때로 혼재된 양상으로 나타난다. 법랑질 형성부전증은 법랑질이 질적으로나 양적으르 부족하며 치수 석회화, 치근 형태 이상, 맹출 장애와 영구치의 매복, 점진적인 치근의 흡수, 선천적 치아 결손, 그리고 전치부나 구치부의 개교합 등의 문제점을 나타낸다. 첫 번째 증례는 만 1세 4개월때 유전치부의 치아색 이상을 주소로 내원한 환자로 그 후 모든 유치 및 영구치에서 법랑질 형성부전증이 관찰되어 수복 술식, 교정적 치료 및 최근 보철 치료까지 완료하였다. 두 번째 증례는 만 9세 3매월된 환아로 유치 및 영구치에서 법랑질 형성부전증이 관찰되었다. 수복 치료가 시행되었고 보철 치료는 성장 완료 후 시행하기로 계획하였다. 본 증례들을 통하여 법랑질 형성부전증은 유치 및 영구치 모두에 발생할수 있으며 장기간의 치료 및 관리가 필요하다는 것을 알 수 있었다.

Benzanilide류의 Carbonyl Stretching Frequency에 대한 치환기의 영향(Ⅰ)

박용태,홍순영 경북대학교 1971 生産技術 Vol.5 No.-

The carbonyl stretching frequencies of substituted benzanilides in the solid phase have been determined. Substituents in benzoyl ring give a good correlation with σ^+. This means that direct resoance interaction is significant for the carbonyl streching. The equation ν=12.11σ^++1650.4, was obtained, making it possible to calculate the carbonyl stretching frequencies for benzanilides. Using the σ^+ values for substituents, it was found that the electron transmission ability of benzanilides is twice as great as that of Chalcones.

소아 간질 아동 어머니의 양육 스트레스 및 부모효능감

박수빈,유한익,전정원,최순호,왕희령,김건우,김진용,고태성 大韓神經精神醫學會 2007 신경정신의학 Vol.46 No.6

Objectives : While parents who foster children with epilepsy would have considerable parenting diSiculties, the parenting stress and sense of competence have not been investigated. We investigated matemal parenting stress, Parenting satisfaction and sense of parenting competence in children with seizure disorders, and the associations with seizure-related variables. Methods : Mothers of 79 children with seizure disorders (41 boys, 38 girls ; mean age, 9.9±2.3 years) and 79 healthy comparison subjects matched for age and sex were recruited for this study. The Korean version of the Parenting Stress Index (K-PSI-SF) and the Parenting Sense of Competence (K-PSOC) were used to assess parenting stress, parenting satisfaction and parenting effcacy. Results : Mothers of children with seizure disorders showed higher scores on stress related to difficult child and child leaming and parenting anxiety compared to mothers of healthy children. In addition, scores on stress related to parental-child interaction and child leaming were significantly associated with parental economic status. Scores on stress from parental-child interaction was also correlated with seizure severity, and stress from child leaming was correlated with seizure type. Sense of parenting competence and anxiety scores were correlated with patemal educational status, respectively. Conclusion : These fndings suggest that mothers of children with epilepsy have greater parenting stress and anxiety and social and seizure-associated factors may affect the parenting stress and anxiety.

중심관이 있는 고효율 축상 유입식 싸이클론 집진기 수치해석적 연구

박지영,장동순,엄태인 忠南大學校 産業技術硏究所 1994 산업기술연구논문집 Vol.9 No.2

A numerical study has been performed in order to investigate the performance of two different shapes of axial-vane type cyclones. The first is a standard type and the other is the one with a central body of the form of an annular tube. Numerical calculations are made using a well-known Patanker's methodology. That is, a control-volume based finite difference method is employed together with the power-law scheme for the descretization of the convection term appeared in governing equation. The pressure-velocity coupling is resolved by the use of the revised version of SIMPLE, say SIMPLEC. The Reynolds stresses are closed using the standard k-ε model. The general pattern of fluid motion is resolved together with the particle trajectory behavior for 8 different particle sizes as a function of swirl strength and central body. The calculation data are in good agreement with the empirical knowledge, for instance, the effect of swirl intensity. The cyclone with a central body shows a high removal efficiency of particulate but more pressure drop than a standard one. Further discusstions are made in detail.

급성대동맥박리증에서 수술전 경식도심초음파도의 역할

박성훈,원태희,원용순,한재진,안재호,이귀용 梨花女子大學校 醫科大學 醫科學硏究所 1999 EMJ (Ewha medical journal) Vol.22 No.1

급성대동맥박리증은, 특히 상행대동맥을 침범한 경우, 응급수술을 요하는 질환으로서 수술전 대동맥판의 손상여부, 질환의 범위, 내벽파열부위의 위치 및 가지혈관의 상태등을 파악하여 수술계획을 수립하여야 한다. 저자들은 상행대동맥을 침범한 3례의 급성대동맥박리증 환자에서 전산화단층촬영과 함께 수술전 또는 필요에 따라 수술후 경식도심초음파도를 시행하여 환자의 치료에 도움을 받았기에 문헌고찰과 함께 보고하는 바이다. Acute type A arotic dissection is a condition which requires emergency surgery. Surgeons want to know not only the extent of the disease but also the exact site of intimal tear as well as the presence of side branch involvement to plan the extent of surgery. Various non-invasive diagnostic tools(transthoracic and transesophageal echocardiography, conventional and spiral computed tomography and magnetic resonance imaging) and invasive angiography are available for the evaluation of the extent of dissection, site of intimal tear and side branch involvement. Each technique has its advantage and disadvantage. Especially, MRI has been accepted as a gold standard for the diagnosis of aortic dissection, but it is immobile and sometimes it cannot give us the information about the small intimal tear site. Transesophageal echocardiography has the advantage of movability and high resolution in addition to the ability of providing comprehensive information about the cardiac function. Because of these advantages, it has been widely utilized for the evaluation of patients with aortic dissection. We performed preoperative transesophageal echocardiography in addition to computed tomography in 3 cases of acute type A aortic dissection and report these cases with the review of articles.

제주도 마래사상충 자충의 정기출현성 분석을 위한 수학적 검토

박영일,강신영,이순형,심태섭 중앙대학교 의과대학 의과학연구소 1981 中央醫大誌 Vol.6 No.2

The different periodicity of microfilariae of Brugia malayi in the blood has been observed by many investigators in the various areas. This study was undertaken to determine the periodicity of microfilaria in Cheju area, where malayan filariasis is endemic, and to compare author's results with that of calculating result from the data reported by Kim(1971). In this study, 9 microfilaria positive cases in Cheju area were analysed. For the mathematical analysis of periodicity pattern in the microfilaria positive cases in Cheju area, the model of Aikat & Das (1976) was applied to the observed data. The periodicity of the present data was distinctly nocturnal pattern in which the peak hour of microfilaria density was 01:37 a. m. and periodicity index was calculated to be 90.13% by using above mathematical model, while the inland area of Korea, the peak hour was at 00:34 a. m. and periodicity index was calculated to be 128.86%. On the base of the above mathematical analysis, it was clearly shown that there was almost no difference in peak hour and periodicity index between the two areas. Also it is certain that the periodicity pattern of Brugia malayi in Korea is tangibly nocturnal and is closely similar to that in the Penang strain of Malaya and Kerala strain of India.

체육고등학교 유도선수들의 일반적 특성에 따른 만족도 연구

박순진,윤익선,김태훈 龍仁大學校 武道硏究所 2002 武道硏究所誌 Vol.13 No.1

This study is to investigate and clarify Life and Athletic Satisfaction of Physical Education Highschool Judo Athletes, based on 12 Physical Education Highschool Judo teams that are registered on Korean Judo Federation of Korean Sports Council in 2002. Among the physical Education Highschool Judo teams, 3 male teams and 3 female teams with winning experience over 3 times for 2 years, 2000-2001 and 3 male teams and 3 female teams without winning experience during the same period, and the responses of the 216 persons were applied to analyze actually. This study brings the follow conclusions by using statistical analysis such as reliability analysis, t-test, one-way ANOVA, correlation analysis, regression analysis, etc. First, Life satisfaction in accordance with the background factors depends on school grades and athletic career significantly. Second, Athletic satisfaction in accordance with the background factors depends on athletic career. Third, Life satisfaction in accordance with the background factors shows a positive correlation in winning prize or not(r=.211*), school grades(r=.212*), and athletic career(r=.268*), and a negative correlation between genders(r=-.265*). Also, athletic satisfaction in accordance with the background factors shows a positive correlation in winning prize or not(r=.200*) and athletic career(r=.158*), and a negative correlation between genders(r=.-336*). Forth, In accordance with the background factors school grades(β=.123) and athletic career(β=.217) effect on life satisfaction and the former (β=.-102) and the latter (β=.200) on athletic satisfaction.