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.

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.

용액법에 의한 나노세공 TiO₂의 합성(Ⅰ)

박태순,김호건 한양대학교 이학기술연구소 2006 이학기술논문지 Vol.9 No.-

금속염을 이용한 용액 침전법과 Alkoxide를 이용한 Sol-Gel법에 의하여, 나노세공 TiO₂ 분말을 합성하고 이를 촉매담체로서 사용하기 위해 수열처리를 통하여 물성을 조절하였다. 분말합성시 용액침전법에서는 70℃, 0.55M의 조건으로, Sol-Gel법에서는 실온(25℃)에서 pH 10의 조건으로 합성하였고 반응시간은 3시간으로 동일하게 하였다. 합성된 분말의 수열처리는 80∼200℃에서 3∼24시간동안 진행하였다. 합성된 분말의 결정상 및 미세구조를 확인하기 위하여 XRD, FT-IR, SEM 등의 기기를 사용하였다. TiO₂ powders with nanopores were synthesized via aqueous precipitation methods using metal salts and via Sol-Gel methods using alkoxide. To use these TiO₂ powders as biocatalyst supports, their physical properties were controlled through hydrothermal treatments. In the aqueous precipitation methods, TiO₂ powders were synthesized under the conditions: reaction temperature 70℃, reaction time 3hours and metal salt concentration 0.55M. In the Sol-Gel methods, TiO₂ powders were synthesized under the conditions: reaction temperature 25℃ reaction time 3hours and solution pH10. The conditions for hydrothermal treatment are as following: temperature 80∼200℃ and heat treatment time 3∼24hours. For the charactenzation of the obtained powders, XRD, FT-IR and SEM techniques were used.

트랙타 부착 대형이앙기 개발 및 재배적 실용성

박성태,장익주,정창화,김상열,김재현,문헌팔,양세준,김순철 한국국제농업개발학회 2002 韓國國際農業開發學會誌 Vol.14 No.3

쌀 생산비를 줄이고 대경지 규모화 영농에 적응할 수 있는 농기계 개발을 목적으로 연구개발한 대규모 경지적응 트랙터 부착 대형벼이앙기의 구성과 특징 및 개발시작기의 재배적 실용성 평가결과를 요약정리하면 다음과 같다. 1. 트랙터 부착 12조 대형벼이앙기는 크게 바퀴자국 제거로타리, 문짝형 정지판, 이앙장치부 등으로 구성되어 있다. 2. 트랙터 부착 12조 이앙기는 트랙터 동력을 이용하여 로타리, 정지 및 이앙작업이 동시에 이루어 질 수 있도록 개발하였다. 3. 바퀴자국을 없애는 날은 기존의 로타리 날을 교체하면 되도록 반달형 날로 제작하였다. 4. 이앙기는 이동시는 접을 수 있도록 설계 제작되어 대형화가 가능하므로 기존 6조 승용이앙기에 비하여 이앙작업 능력이 1.5배 이상이었다. 5. 트랙터 부착 대형벼이앙기는 트랙터와 같은 큰 동력원을 이용할 수 있으므로 측조시비기, 긴매트모 탑재 등 다양한 작업기 및 기능을 추가로 부착 가능하도록 설계되었다. 6. 트랙터 부착 대형벼이앙기는 어린모 및 중묘이앙시 결주율은 3.0∼4.3%로 기계이앙기 결주 허용범위 5% 미만이었다. 하지만 무경운 논에서는 이앙작업은 가능하나 부묘율이 다소 높은 점은 보완이 필요하다. To develop a labor saving rice cultivation technology, a new tractor attached rice transplanter has been developed for large scale farming and its field performance was evaluated. The rice transplanter consists of three major parts such as rotary for removing tractor tire furrow, door-shaped soil leveling plate and transplanting equipment. The rice transplanter is operated using the power of the tractor and performs rotary, harrow and seedling transplanting simultaneously. A half moon shaped rotary blade was found to be very efficient to remove tire furrow developed during seedling transplanting and the original rotary blade can be replaced easily with existed rotary blade. The seedling transplanting part of the transplanter was designed to fold into small size and the transplanting efficiency of the transplanter was found to be 1.5 times higher than that of the conventional riding type six row transplanter. Since the transplanter is operated through a strong power of the tractor, the additional attachment such as fertilizer application apparatus and long mat rice seedling carrier is possible. Based on the field performance of the transplanter, although the missing hill percentage showed roughly with 3.0∼4.3% for 10-day and 30-day old seedlings but the percentage is less than 5% which is maximum missing hill permit in the transplanting rice. Seedling transplanting in no-tillage field condition is acceptable but floating seedling percentage is still high and thus further technology improvement for minimizing floating seedling percontage is needed.

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.

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.

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.

브로콜리 줄기의 callus배양 및 항노화 효과

박태진 ․ 이상민 ․ 조준환 ․ 남수호․ 신주은 ․ 김대환 ․ 이인순 ․ 박흠대 대구대학교 산업기술연구소 2018 産業技術硏究 Vol.29 No.2

Broccoli (Brassica oleracea var. italica) is well known of excellent antioxidant food so that we researched on its anti-aging and callus differentiation from the tissue of broccoli stem by MS medium with exo-phytohormone as IAA, kinetin. The functional materials of callus tissue were extracted with water and 70% EtOH after 16 days progressed callus formation. As a result, callus differentiation and formation were showed higher efficiency at B5 condition medium (0.1 mg/L IAA, 0.4 mg/L). The callus cultured on B3, B6 and B7 medium were observed the reaction of enzymatic browning to callus tissue. The anti-aging effect on the extract was experiment with DPPH radical scavenging and catalase(CAT). The activity of DPPH radical scavenging was showed high value in water extract of B1, B6, B8, B9 and was increased depending on sample concentration. However, in case of the extract of 70% EtOH, DPPH activity was showed different effect depending on the sample kind. CAT activity was found the highest enzyme unit in the extract of natural broccoli and B1(no add exo-phytohormone). It is to express that a broccoli itself is great food for anti-aging. Therefore, callus formation of broccoli considers having no economic efficiency to do development of anti-aging product.