A Study on Electrical Characteristics of Outdoor Termination with Viscosity of Insulating Oil

Jin‑Wook Choe,Seok‑Hyun Nam,Jin‑Gyu Kim 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.3

Outdoor terminations connecting overhead transmission lines and power cables comprise a stress relief cone, which is made of silicone rubber, and insulating oil in a composite or porcelain insulator. The lower the insulating oil viscosity, the greater is its ease of injection. However, the swelling and the degree of change in the electrical properties of the silicone rubber increase with a decrease in the insulating oil viscosity. Therefore, the efect of the expected change in the electrical proper‑ ties of the silicone rubber on the outdoor termination quality should be examined before choosing the insulating oil. In this study, specimens made of insulating and semiconducting silicone rubber were made to swell by impregnating them with three types of insulating oils with diferent viscosities. The AC breakdown strength of the swollen insulating specimens and the volume resistivity and relative permittivity of the semiconducting specimens were measured. The Weibull statistical analysis showed that the lower the insulating oil viscosity, the lower was the AC breakdown strength in overlapping con‑ fdence intervals. The volume resistivity and relative permittivity of the semiconducting specimens changed considerably with a change in the viscosity of the insulating oil. In particular, the volume resistivity of the specimen impregnated with the lowest viscosity insulating oil was 1.57×106 Ω m, indicating loss of semiconducting properties. Furthermore, the efect of changes in the electrical characteristics of the specimens on the outdoor termination quality was examined by performing an electric feld analysis. Compared with the other oils, impregnation with the lowest viscosity insulating oil resulted in the electric feld strength at the edge of the outer semiconducting layer increasing by 15.7%.

2007년 대한감염학회 권장 성인 예방접종 권장안

강진한,김홍빈,손장욱,이상오,정문현,정희진,최영화,최정현,최준용,최희정 대한감염학회 2008 감염과 화학요법 Vol.40 No.1

In 2007, the Korean Society of Infectious Diseases recommended an immunization schedule for adults residing in Korea. This recommendation includes four categories: standard immunization for healthy persons, supplementary immunization for persons with underlying illnesses, recommendations for health-care personnel and for international travelers. The Standard Immunization Schedule consists of universal vaccination (tetanus-diphtheria/tetanus-diphtheria-pertussis (Td/Tdap); hepatitis A vaccine for persons aged 20s; human papilloma virus vaccine for women under 26 years old; meningococcal vaccine for military recruits and college students in dormitories; influenza vaccination for persons aged 50 years or more and pregnant women; and pneumococcal vaccination for persons aged 65 years or more) and catch-up vaccination (hepatitis A vaccine for persons aged 30s; hepatitis B vaccine, varicella and MMR vaccines for persons who have uncertain specific immunities). The Supplementary Immunization Schedule recommends 4 vaccines, i.e., pneumococcal, influenza, meningococcal, and Haemophilus influenzae type b, appropriate to the underlying illnesses, and confirmation of the presence of antibodies to hepatitis A and hepatitis B. The Recommendation for Health-Care Personnel includes universal vaccination (influenza and pertussis) and catch-up vaccination (hepatitis B, measles-mumps-rubella and varicella for seronegative health-care personnel). The Recommended Immunization for International Travelers focuses reinforcement of vaccinations for healthy persons and includes certain immunizations necessary for international travel (yellow fever, meningococcal, plaque, tick-borne encephalitis, and cholera). These guidelines can be seen at www.ksid.or.kr.

이차성 기질화 폐렴이 동반된 피부근염 1예

박철연,권정석,정진욱,이충기,현대성,최정윤 영남대학교 의과대학 2008 Yeungnam University Journal of Medicine Vol.25 No.2

Dermatomyositis is characterized by progressive, symmetric, Proximal muscle weakness and a nonsuppurative inflammatory myopathy of unknown etiology involving predominantly skeletal muscles. It is also characterized by typical skin lesions. Interstitial lung disease has a poor prognosis when it is associated with dermatomyositis. Organizing pneumonia is a disease in which granulation tissue fills the lumina of terminal and respiratory bronchioles and extends into the distal airspaces. The cryptogenic nature of the process is appreciated in that organizing pneumonia patterns of injury can be seen in secondary forms of the disease (secondary organizing pneumonia). Organizin pneumonia has been reported to occur in 5~10% in dermatomyositis-polymyositis patients Anti-histidyl tRNA synthetase antibody (anti-Jo-1) is a Predictive disease marker that is reported to occur in up to 70% of patients. We describe a 49-year-old male dermatomyosits patient who presented with organizing pneumonia and was found to have negative anti-Jo-1 antibody.

申櫶(1811~1884)의 생애와 활동

최진욱(Choe Jin-Wook) 호서사학회 2010 역사와 담론 Vol.0 No.57

Sin H?n worked as a central bureaucrat active in dealing with the Western powers during the Opening-Ports period. He not only proposed the maritime defense plan influenced by the movement of people, the degree of the external pressure, and the accumulation of experience, but also practiced it. Taught by such famous Sirhak scholars as Ch?ng Yagyong (1762-1836) and Kim Ch?ngh?i (1786-1856), Sin gained a nick name of Confucian General due to his great knowledge of Confucianism while displaying the Sirhak trend. He also befriended such prominent figures as Monk Ch'o?i (1786-1866), in endeavor to reform the Buddhism at that time, and Kang Wi (1820-1884) who asserted the necessity of opening-door policy. The broad friendship helped equip Sin with a flexible way of thinking and a deeper understanding of international affair. And, the first three years of his civil service at the court of Prince Hyomy?ng (1809-1830) motivated him to maintain reform policy even when he served as a high-ranking official in government. As the internal and external problems escalated in the 1860s, Sin started suggesting a series of pragmatic policies according to the realty of Chos?n. His plans characterized the constructive and pragmatic reformulation of the Sirhak discourse on national defence. They also included some basic contents from the maritime defense plan of a Qing scholar Wei Yuan (1794-1856). Right after the French Disturbance of 1866, Sin proposed a memorial addressing comprehensively military defence plans, most of which were accepted by the court. He also emphasized the importance of firearms and artillerymen and tried to make some new weapons, including floating mine and moving breech-loading cannon, in the similitude of the Western ones. Meanwhile, he advocated a radical state policy that required a certain degree of concession from the ruling class in order to encourage the voluntary participation of common people which was the essential part in battle. As well known, Sin attended the Treaty of Kanghwa as the representative of Chos?n in 1876. He took no passive or disgraceful attitude in the process. Although the draft of the treaty was made by the Japanese side, its final agreement came to reach under the leadership of the Chos?n side. The experiences of Sin and other diplomatic experts in the treaty became integral to the direction of the Enlightenment Policy of Chos?n in the future.

Real-world effectiveness of a single conventional disease-modifying anti-rheumatic drug (cDMARD) plus an anti-TNF agent versus multiple cDMARDs in rheumatoid arthritis: a prospective observational study

( Min Wook So ),( Sang-hyon Kim ),( Dong Wook Kim ),( Yoon-kyoung Sung ),( Jung-yoon Choe ),( Sang-il Lee ),( Jin-wuk Hur ),( Hye-soon Lee ),( Sang-heon Lee ),( Jin Ran Kim ) 대한류마티스학회 2024 대한류마티스학회지 Vol.31 No.2

Objective: The objective of this prospective, observational multicenter study (NCT03264703) was to compare the effectiveness of single conventional disease-modifying anti-rheumatic drug (cDMARD) plus anti-tumor necrosis factor (TNF) therapy versus multiple cDMARD treatments in patients with moderate-to-severe rheumatoid arthritis (RA) following cDMARD failure in the real-world setting in South Korea. Methods: At the treating physicians’ discretion, patients received single cDMARD plus anti-TNF therapy or multiple cDMARDs. Changes from baseline in disease activity score 28-joint count with erythrocyte sedimentation rate (DAS28-ESR), corticosteroid use, and Korean Health Assessment Questionnaire (KHAQ-20) scores were evaluated at 3, 6, and 12 months. Results: Of 207 enrollees, the final analysis included 45 of 73 cDMARD plus anti-TNF and 91 of 134 multiple-cDMARD recipients. There were no significant between-group differences (BGDs) in ANCOVA-adjusted changes from baseline in DAS28-ESR at 3, 6 (primary endpoint), and 12 months (BGDs -0.18, -0.38, and -0.03, respectively). More cDMARD plus anti-TNF than multiple-cDMARD recipients achieved a >50% reduction from baseline in corticosteroid dosage at 12 months (35.7% vs 14.6%; p=0.007). Changes from baseline in KHAQ-20 scores at 3, 6, and 12 months were significantly better with cDMARD plus anti-TNF therapy than with multiple cDMARDs (BGD -0.18, -0.19, and -0.19 points, respectively; all p≤ 0.024). Conclusion: In the real-world setting, relative to multiple cDMARDs, single cDMARD plus anti-TNF therapy significantly improved quality-of-life scores and reduced corticosteroid use, with no significant BGD in disease activity, in RA patients in whom previous cDMARD therapy had failed.

팽윤에 의한 실리콘 고무 특성 변화에 관한 연구

최진욱(Jin-Wook Choe),남석현(Seok-Hyun Nam),김진규(Jin-Gyu Kim) 대한전기학회 2019 전기학회논문지 Vol.68 No.9

In order to build underground the transmission line, it is necessary to install outdoor terminations that connect overhead transmission lines and underground power cables. The inside of the outdoor termination is filled with insulating oil and a stress relief cone made of silicone rubber is assembled at the end of outer semiconducting layer. Insulating oil is heated to lower viscosity prior to injection, which requires additional equipments and more time. It is necessary to examine the influence of impregnated silicone rubber on the use of low-viscosity insulating oil that can be injected without heating. In this paper, we investigated how much silicone rubber swells depending on the viscosity of three different insulating oils. The mechanical and electrical properties such as tensile strength, elongation, volume resistivity, relative permittivity, etc., of the fully swollen silicone rubber were measured. In addition, the chemical analyzes of the fully swollen silicone rubber through FTIR and TGA were performed.

에폭시 몰딩에 의한 부스바 온도 저감 효과에 관한 연구

최진욱(Jin-Wook Choe),이웅엽(Woong-Yeop Lee),남석현(Seok-Hyeon Nam),김진규(Nam?Jin-Gyu Kim) 한국조명·전기설비학회 2018 조명·전기설비학회논문지 Vol.32 No.11

As the number of large buildings and factories that consume a lot of electric power is increased, the use of bus ducts that can flow high current is increasing. The NSPB which is mainly used to connect the transformer and the switchboard has a structure in which a three-phase bus bars are spaced apart in a single metal enclosure. The bus bars are made of bare conductors or conductors coated with an epoxy powder or a heat-shrinkable tube. Bus ducts are required to have insulation characteristics for voltage, temperature characteristics due to current and mechanical characteristics due to short-circuit electromagnetic force. In this paper, temperature characteristics of epoxy molded bus bars were investigated through experiments. The maximum temperature change of the conductor with epoxy molding, the maximum conductor temperature change with the number of conductors and the space when the epoxy molding volume was the same and the maximum conductor temperature change with increasing current were compared.

J-Tube 내부 해저케이블의 열적 스트레스 조건에 따른 절연특성 분석 연구

최진욱(Jin-Wook Choe),이승원(Seong-Won Lee),권익수(Ik-Su Kwon),김해종(Hae-Jong Kim) 한국신재생에너지학회 2023 한국신재생에너지학회 학술대회논문집 Vol.2023 No.6

MV급 하이브리드 NSPB 개발

최진욱(Jin-Wook Choe),이웅엽(Woong-Yeop Lee),남석현(Seok-Hyeon Nam),김진규(Jin-Gyu Kim) 대한전기학회 2019 대한전기학회 학술대회 논문집 Vol.2019 No.7

The Influence of Face Shields on the Quality of Colonoscopy in the Era of the COVID-19 Pandemic

Lee Jin Wook,Lee Hyo Jeong,Kim Dae Sung,Yoon Jiyoung,Hong Seung Wook,Hwang Ha Won,Lee Jong-Soo,Kim Gwang-Un,Lee Sinwon,Choe Jaewon,Park Jin Hwa,Yang Dong-Hoon,Byeon Jeong-Sik 거트앤리버 소화기연관학회협의회 2022 Gut and Liver Vol.16 No.3

Background/Aims: The worldwide coronavirus disease 2019 pandemic has led endoscopists to use personal protective equipment (PPE) for infection prevention. This study aimed to investigate whether wearing a face shield as PPE affects the quality of colonoscopy. Methods: We reviewed the medical records and colonoscopy findings of patients who underwent colonoscopies at Asan Medical Center, Korea from March 10 to May 31, 2020. The colonoscopies in this study were performed by five gastroenterology fellows and four expert endoscopists. We compared colonoscopy quality indicators, such as withdrawal time, adenoma detection rate (ADR), mean number of adenomas per colonoscopy (APC), polypectomy time, and polypectomy adverse events, both before and after face shields were added as PPE on April 13, 2020. Results: Of the 1,344 colonoscopies analyzed, 715 and 629 were performed before and after the introduction of face shields, respectively. The median withdrawal time was similar between the face shield and no-face shield groups (8.72 minutes vs 8.68 minutes, p=0.816), as was the ADR (41.5% vs 39.8%, p=0.605) and APC (0.72 vs 0.77, p=0.510). Polypectomy-associated quality indicators, such as polypectomy time and polypectomy adverse events were also not different between the groups. Quality indicators were not different between the face shield and no-face shield groups of gastroenterology fellows, or of expert endoscopists. Conclusions: Colonoscopy performance was not unfavorably affected by the use of a face shield. PPE, including face shields, can be recommended without a concern about colonoscopy quality deterioration.