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.

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.

Hand Ball 競技에 있어서의 Shoot에 대한 分析

朴淳哲,孫泰烈 成均館大學校 1980 論文集 Vol.27 No.-

Purpose The main purpose of this study is to analysis of the shooting tendency in distance, angle, and form in Hand Ball game. Subjects To this end, the resercher has selected 35 games from the participating teams including 9 teams of male college, 9 teams of Female college……, and 8 teams of male high school, 9 teams of female. high school in the 60th National Sports Festival Hand-Ball Came held in Dae-Jun October 1979. Methods The researcher of this study classify the measurement into the following categories; 1. Distsnction of the Shooting Distance 2. Distinction of the Shooting Angle 3. Distinction of the Shooting Form Results The Results May Summarized as Follows; 1. The times of shooting; Male College 746 Female college 654 Male High School 597 Female High School 429 2. The Point rate of the shooting; Male College 47.31% Female College 45.56% Male High School 46.90% Female High School 42.65% 3. The point rate of the penalty-throw; Victoried Game's M. 72% Defeated Game's M. 55%

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.

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.

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.

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.