원전 사고처리 지원시스템(ECAS) 개발

최영환,김영미,고한옥,Choi, Young Hwan,Kim, Yopng Mi,Ko, Han Ok 한국압력기기공학회 2009 한국압력기기공학회 논문집 Vol.5 No.2

In this study, Event Corrective Action Supporting System (ECAS) is developed for the accident evaluation in nuclear power plant. The ECAS system can be used in supporting regulator and/or operator under event situation in nuclear power plants. The ECAS system consists of 5 modules including failure location module, failure analysis module, failure integrity evaluation module, system vulnerability evaluation module, and reporting and operating experience feedback module. The ECAS system will be used as sub module of Knowledge-Based Event Evaluation Network (K-EvENT) which is developing for the against the accident in nuclear power plants.

고강도 콘크리트를 사용한 각형 CFT 기둥의 축력-모멘트 상관곡선

최영환,김강수,최성모,이상섭,Choi, Young Hwan,Kim, Kang Su,Choi, Sung Mo,Lee, Sangsup 한국강구조학회 2007 韓國鋼構造學會 論文集 Vol.19 No.6

본 논문은 55 MPa 이하 강도의 콘크리트를 사용한 CFT 기둥에 대한 P-M 상관곡선을 제안한 선행연구의 후속연구로서, 2005 AISC에서 새롭게 포함된 55 MPa 이상의 고강도 콘크리트를 사용한 정방형 CFT 기둥의 P-M 설계식을 제안하였다. 선행연구에서 제안한 개념을 적용하여 고강도 콘크리트를 사용한 CFT에서의 최대모멘트와 최대모멘트시의 압축력을 구하기 위해 강관의 폭두께비(b/t)와 강관의 항복강도에 대한 콘크리트의 상대강도(fck/Fy)를 중요 변수로 총 36개의 대상단면을 선정하여 Fiber Analysis를 통한 변수해석을 수행하였다. 강관의 응력-변형율 관계는 완전탄소성으로 가정하였고 콘크리트는 고강도 콘크리트에 적용가능한 Sakino의 모델을 이용하였다. 변수해석으로부터 얻어진 결과로부터 상기의 두 변수를 이용하여 고강도 콘크리트를 사용한 각형 CFT 기둥의 설계에 쉽게 사용할 수 있는 설계식을 제안하였다. 기존의 실험결과와 비교한 결과 본 논문에서 제시하는 방법은, 2005 AISC에서 제시하는 방법에 비해 보다 더 쉽고 간단하게 사용될 수 있는 것으로 나타났다. In this study, a new design equation was presented for square CFTs with high-strength concrete subjected to axial compression and bending. In a previous study, a design equation for square CFTs with normal strength concrete was proposed. A parametric study by fiber analysis was performed taking the width-to-thickness ratio (b/t) and the relative concrete strength to the yield strength of the steel tube (fck/Fy) as the main parameters of this study to determine the maximum moment and the axial load at the maximum moment. A new constitutive model for concrete was adopted for fiber analysis in order to take into account the effect of high-strength concrete. The results of the parametric study were embedded into the method which was presented in the previous study to formulate a new design equation that can be easily used for estimating the strength of square CFTs with high-strength concrete.

국내 가압경수형 원자로에 대한 가압열충격 기준온도 평가

최영환,박정순,정명조,Choi, Young Hwan,Park, Jeong Soon,Jhung, Myung Jo 한국압력기기공학회 2010 한국압력기기공학회 논문집 Vol.6 No.2

The evaluation method for the failure frequency of reactor vessel under pressurized thermal shock(PTS) is developed using probabilistic fracture mechanics. The probabilistic reactor integrity evaluation code, named R-PIE code, is developed. The validity and uncertainty of the R-PIE code is investigated. The reactor failure frequencies under PTS for Kori-1 nuclear power plant and other type of domestic nuclear power plants are evaluated. The reference PTS temperature for domestic nuclear power plants is obtained for the rule making against PTS failure.

콘크리트 충전 각형강관 기둥의 폭두께비 제한에 관한 연구

최영환,Choi, Young-Hwan 한국강구조학회 2012 韓國鋼構造學會 論文集 Vol.24 No.4

구조적 우수성이 입증된 콘크리트 충전 강관 (CFT) 시스템은 폭두께비가 큰 강관을 사용할 때 더욱 경제적인 설계가 될 수 있다. 하지만, 현재 국내외의 규준에서는 CFT에 사용할 수 있는 강관의 폭두께비를 제한하고 있어 건설 재료를 보다 더 효율적으로 활용할 수 있는 가능성을 미리 차단하고 있다. 본 연구에서는 폭두께비 60, 70, 80, 90, 100를 갖는 각형 단주 CFT에 대해 압축실험을 실시하여 CFT에서의 좌굴 후 내력을 확인하였고 기존의 규준에서 제시한 폭두께비 제한치를 완화한 식을 제시하였다. The concrete-filled steel tube (CFT) that has an excellent performance can be more economically used when the steel tube has a large width-to-thickness ratio. However, the international provisions such as American Institute of Steel Construction (AISC) limit the use of a slender plate in CFT members, resulting in a less optimal use of CFT. This study verifies the post buckling strength of CFT columns through the experimental program for Hollow Steel Sections (HSS) and CFTs with a with-to-thickness ratio ranged 60 to 100. The study also proposes a relaxed limitations of with-to-thickness ratio compared to the one specified in the current standards.

원전사고 평가를 위한 원전 사건유형분석 시스템(ETAS) 개발

최영환,김영미,Choi, Young Hwan,Kim, Young Mi 한국압력기기공학회 2009 한국압력기기공학회 논문집 Vol.5 No.2

In this study, Event Type Analysis System (ETAS) is developed for the accident evaluation in nuclear power plant. The ETAS system can be used in supporting regulator and/or operator under event situation in nuclear power plants. The ETAS system can categorize the all transient events to 3 categories such as Down-2000, Down-2173, and Slow Fluctuation. We develop the program structure for ETAS system and web-based ETAS system. The ETAS system will be used as sub module of Knowledge-Based Event Evaluation Network (K-EvENT) which is developing for the against the accident in nuclear power plants.

원주방향균열이 존재하는 원전 배관계통의 파괴거동에 관한 실험적 연구(I) - 직관부에서의 균열거동 평가 -

최영환,박윤원,Choi, Young-Hwan,Park, Youn-Won,Wilkowski, Gery 대한기계학회 1999 大韓機械學會論文集A Vol.23 No.7

The purpose of this study is to investigate experimentally the effects of both seismic loading and crack length on the fracture behavior of piping system with a circumferential crack in nuclear power plants. The experiments were performed using both large scale piping system facility and 4 points bending test machine under PWR operating conditions. The difference in the load carrying capacities between cracked piping and non-cracked piping was also investigated using the results from experiments and numerical calculations. The results obtained from the experiments and estimation are as follows : (1) The safety margin under seismic loading is larger than those under quasi static loading or simple cyclic loading. (2) There was no significant effect of crack length on tincture behavior of piping system with both a surface crack and a through-wall crack. (3) The load carrying capacity in cracked piping was reduced by factors of 7 to 46 compared to non-cracked piping.

호중구 감소된 급성 림프구성 백혈병환아에서 발생한 Pneumocystis carinii 폐렴 1례

최영환,민기식,김종완,김광남,유기양,Choi, Young Hwan,Min, Ki Sik,Kim, Jong Wan,Kim, Kwang Nam,Ryoo, Ki Yang 대한소아감염학회 1997 Pediatric Infection and Vaccine Vol.4 No.1

Pneumocystis carinii pneumonia mainly occurs in immunocompromised patients and it is also known of major cause of death in children with acute lymphoblastic leukemia. After consolidation chemotherapy, acute lymphoblastic leukemia children is developed Pneumocystis carinii pneumonia frequently no an opportunistic infection but there were no controlled studies which have been performed to evaluate the usefulness of corticosteroid in Pneumocystis carinii pneumonia with acute lymphoblastic leukemia. We experienced a case of Pneumocystis carinii pneumonia in acute lymphoblastic leukemia with febrile neutropenic 6 years old girl. She was treated with trimethoprim-sulfamethoxazole and prednisone. We report this case with brief review of related literature.

감마인터페론이 말초혈액 단핵구의 IgE 생성능과 FceRII 표현에 미치는 영향

최영환(Young Hwan Choi),강천일(Cheon Il Kang),서영익(Young Ik Seo),황윤근(Youn Keun Hwang),강문수(Moon Soo Kang),이종명(Jong Myung Lee),김능수(Nung Soo Kim) 대한내과학회 1994 대한내과학회지 Vol.46 No.1

N/A tendency to decrease after 3days culture of PBMCs with IFN- y in both allergic asthmatics ad healthy individuals. And significant reduction was observed at the concentration of IFN-y 1000 IU/ml in healthy individuals. 3) In case of allergic asmatics, the IgE levels in supernatants of 6days' PBMCs culture with IFN-Υ were significantly lower than those of spontaneous culture. 4) The IgE levels in supernatants of 6 days PBMCs culture with PHA and INF-Υ were significantly higher than those of IFN-Υ only. Conclustion: In asymptomatic patients with allergic asthma, culture of PBMCs with IFN-Υ showed dosedependent reduction. in IgE production and FcεRII expression. These findings may suggest that IFN-Υ is deeply involved in both IgE production and FceRII expression of PBMCs.

기초연기 교육과정에서 발성 이전 단계의 호흡훈련 방법 연구

최영환(Young-Hwan Choi) 한국콘텐츠학회 2015 한국콘텐츠학회논문지 Vol.15 No.5

배우로서 좋은 화술을 구사하기 위해 자연스런 호흡과 발성이 전제되어야 하는데 이 논문에서는 발성 이전 단계인 호흡 훈련 방법에 초점을 맞추어 논구하고 있다. 기존의 호흡과 발성훈련에 대한 연구는 성악, 요가, 단전호흡, 의학적 관점에서 접근한 것이 주류를 이룬 반면에, 배우의 연기훈련의 일환으로 되어진 연구는 그 중요성에 비해 상대적으로 많지 않다. 더구나 그러한 연구도 대체적으로 호흡과 발성, 화술을 전반적으로 다루는 연구가 대부분이다. 따라서 본 연구자는 이 논문에서 연구 법위를 좁혀 발성 이전 단계의 호흡훈련, 특히 배우의 상상력과 이미지를 통해 극 속에서 존재할 법한 다양한 상황 속에서 자연스럽게 호흡하는 훈련법을 집중적으로 연구하였다. An actor should be well-trained at the natural breathing and phonation in order for a good diction. This thesis is focused on the breathing training method at the pre-phonation stage. The past research on the breathing and phonation training was generally for vocal music, yoga, or those which were approached by the medical view point, whereas there are not so many researches which are approached for an acting training even though it is quite important for actors. In addition, such researches have been given an overview of breathing, phonation and diction. Therefore, this thesis which is focused on the breathing training at the pre-phonation stage suggests the natural breathing training method through the imagination and image in the various situations which could exist in the drama.

소개글: 아쉬운 교량들-아치교

최영환(Young Hwan Choi) 한국강구조학회 2006 韓國鋼構造學會誌 Vol.18 No.1