발톱에 발생한 역행조갑 환자의 치험례

최석민,김철한,강상규,탁민성,Choi, Seok-Min,Kim, Chul-Han,Kang, Sang-Gue,Tark, Min-Seong 대한성형외과학회 2010 Archives of Plastic Surgery Vol.37 No.2

Purpose: Retronychia is the embedding of the nail into proximal nail fold. Retronychia starts with disruption of the longitudinal growth of the nail. With the growth of a new nail, the old one is pushed upwards and backwards. This leads to embedding of the top nail into the ventral aspect of the proximal nail fold and results with chronic paronychia. We present a case of retronychia that was rarely reported in the literature. Methods: A 46-year old female presented with a 3-month history of painful right first, 2nd, 3rd toenail changes. Although she was initially treated with broad spectrum antibiotics, she did not response to therapy. Later, she presented to our department because of progressively worsening pain that impaired her walking. Physical examination revealed with proximal nail fold erythema, painful swelling, yellowish nail discoloration, and distal onycholysis. Bacterial and fungus culture showed no organism. Treatment was surgical nail avulsion under local anesthesia. Results: The postoperative course was uneventful. 10 months later, the patient had a normal growing nail and was free of symptoms. Conclusion: We report a case of retronychia on toenail. Retronychia is a proximal nail plate ingrowth into the proximal nail fold which is associated with multiple generations of nail plate misaligned beneath the proximal nail. Management consisted of simple avulsion of superimposed nail. Retronychia is suspected with a persistent paronychia, particularly in the setting of trauma. Avulsion of the top nail confirms the diagnosis and may be curative if the underlying nail appears healthy.

가스터빈 블레이드 삼각 내부 냉각 유로 종횡비에 따른 열전달 특성

최석민(Seok Min Choi),최승영(Seungyeong Choi),박희승(Hee Seung Park),조형희(Hyung Hee Cho) 대한기계학회 2021 大韓機械學會論文集B Vol.45 No.3

본 연구에서는 가스터빈 블레이드 전단부의 삼각 내부 유로의 종횡비에 따른 유동 및 열전달 특성에 대하여 분석하였다. 종횡비 1:0.5, 1:1, 1:2의 세 가지 유로 형태를 수치해석을 통해 비교하였다. Re=10,000인 조건에서 해석을 수행하였다. 결과를 살펴보면 종횡비가 작은 유로에서 이차유동의 발생이 더 크게 나타나는 것을 확인하였다. 이로 인해 leading edge 부근에서 국소적으로 높은 열전달이 나타나는 것을 확인하였다. 하지만 종횡비 1:1의 유로에서 이차 와류와 요철에 의한 주유동의 열전달 강화 효과가 복합적으로 잘 나타나게 되어 평균적으로 높은 열전달 분포를 보이는 것을 확인하였다. 이로 인해 열성능계수도 가장 높게 나타나는 것을 확인하였다. 따라서 가스터빈 블레이드 전연부의 내부유로의 형태는 종횡비 1:1이 가장 적합하다고 판단된다. This study investigated the flow and heat transfer characteristics of the triangular internal passage of the leading edge of a gas turbine blade with respect to the aspect ratio. Aspect ratios of 1:0.5, 1:1, and 1:2 were compared using numerical simulations. The simulations were conducted under the condition of Re = 10,000. The results demonstrated that the 1:0.5 aspect ratio case exhibited higher strength of the secondary flow. Therefore, relatively high heat transfer distributions were observed near the leading edge region. However, the 1:1 aspect ratio case exhibited higher average heat transfer distributions owing to the complex effect of the main flow by the rib and secondary flow. Therefore, the thermal performance ratio is the highest at the 1:1 aspect ratio channel, and we conclude that the 1:1 aspect ratio is suitable for the internal passage of the blade leading edge.

방열판을 이용한 배열회수보일러 케이싱 열응력 감소 방안

최석민(Seok Min Choi),손호성(Ho-Seong Sohn),한솔(Sol Han),김풍일(Poongil Kim),한봉기(Bong Gi Han),조형희(Hyung Hee Cho) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.6

초등학교 창의성 교육 접근 방식에 대한 비판적 검토

최석민 ( Seok Min Choi ) 한국초등교육학회 2006 초등교육연구 Vol.19 No.2

A common approach of creativity seems to have been that creativity can be directly cultivated in a separated course. But in this approach there are several points to be critically examined. a) Creativity cannot be promoted solely by training the cognitive skills. Increasingly, researchers are focusing on the social and contextual factors that promote creative activity. b) Creativity may be something habitual rather than substantial. so it may not be a substance to be imbued but an attitude or habit to be practiced. c) Creativity would have to be practiced amid with other aspects of thinking or educational values. d) The generalized view of creativity should be viewed according to its specific context. A specific context, may require a specific knowledge base for the creativeness in that area. Teaching of creativity is not to be confined to a specific period or area of teaching. It may instead have to be diffused over all the subject areas of teaching. But their programs wouldn`t necessarily have to be called those of creativity education. It would have to fall under the rubric of the good learning. It would also have to be emphasized as one, only one, -- not the one -- element of good learning. It would have to be under the umbrella of holistic learning, for the overall educational interest as well as its specific effect. In conclusion, the infusion model of education might be successfully adopted as one of the dominant approaches in teaching creative thinking. Hallman`s research on Dewey`s concept of the creativity and Csikszentmihalya`s in-depth analysis of the ninety-one exceptional individuals support it.

배열회수보일러 케이싱 파손방지를 위한 열응력 저감 Heat Sink 설치 효과

최석민(Seok Min Choi),김선호(Seon Ho Kim),김풍일(Poongil Kim),고석재(Seok Jae Ko),정희봉(Hee Bong Chung),한봉기(Bong Gi Han),조형희(Hyung Hee Cho) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11

This study investigate thermal stress on the HRSG casing adopting heat sink by experimental data and numerical simulation. Heat sink is adopted on the HRSG casing to reduce the thermal stress. Thermocouples are installed on the operating HRSG casing to measure the temperature. Measured data shows that temperature gradient is rapid on the middle section of the HRSG casing. On the middle section, the temperature gradient is average 100℃ and it will cause extreme thermal stress. By numerical simulation we found out the local temperature data and measeared the thermal stress on the HRSG casing. Thermal stress on the middle section of HRSG casing is the highest and we can easily assume that the breakages are frequently happens on that position. So, we installed the heat sink on the vulnerable position on the HRSG casing to reduce the thermal stress. By installing the heat sink, we can reduce the peak thermal stress by 10% on the vulnerable position. As a result, heat sink can reduce the thermal stress on the HRSG casing.

가스터빈 블레이드 내부 배열별 핀-휜 지름 변경에 따른 냉각 성능 특성 변화

최석민(Seok Min Choi),김정주(Jeong Ju Kim),김태현(Taehyun Kim),조형희(Hyung Hee Cho) 대한기계학회 2021 大韓機械學會論文集B Vol.45 No.1

가스터빈 블레이드의 핀-휜 배열의 국소 냉각 성능을 조절하기 위하여 핀-휜의 지름 변경에 따른 효과를 분석하였다. 엇갈림 배열 핀-휜이 설치된 내부 유로의 3열의 지름이 다른 경우의 유동 및 열전달 특성 변화를 수치해석을 통해 분석하였다. 엇갈림 배열의 핀-휜이 설치된 기존 형상, 3열의 핀-휜 지름이 20% 증가된 형상, 3열의 핀-휜 지름이 40% 증가된 형상을 각각 비교하였다. 수치해석 결과 핀-휜 배열의 지름이 증가하는 경우 내부 유동의 유속이 가속되었으며, 3열의 핀-휜 지름이 향상된 영역의 국소 열전달 분포가 기존 형상에 비해 증가하는 것을 확인하였다. 또한 바닥면의 평균 열전달 분포가 증가하는 것을 확인하였다. 반면 증가된 지름의 크기로 인해 압력손실은 증가하였으나, 열성능계수는 1.2x 형상에서 0.4% 가량 증가하였다. 이를 통해 향후 가스터빈 핀-휜 냉각 유로 설계 시 핀-휜 지름 크기변경을 통해 냉각성능을 국소적으로 조절할 수 있는 것으로 판단된다. The effect of different diameters of pin-fin array was analyzed to control the cooling performance of internal passage of the gas turbine. Numerical simulations were conducted to determine the flow and thermal characteristics of two different diameter of pin-fin array effect. A staggered pin-fin array with same pin-fin diameter, 1.2x pin-fin array with 20% large pin-fin diameter at the bottom 2 array, and 1.4x pin-fin array with 40% large pin-fin diameter at the bottom 2 array were compared. The results showed that higher velocity was observed in large pin-fin array cases and different local heat transfer distributions were observed near large pin-fin arrays. Furthermore, the heat transfer distributions on the endwall increased. The friction factor increased owing to the installation of larger pin-fin, and thermal performance factor was increased to 0.4% in 1.2x pin-fin array. Therefore, installation of larger diameter pin-fin will be helpful in controlling the cooling performance of pin-fin array internal passage of gas turbine blades.

조류에 의한 해상태양광 패널의 기울임 각도 변화에 따른 풍하중 특성 분석

최석민(Seok-Min Choi),박창대(Chang-Dae Park),조성훈(Sung-Hoon Cho),이가람(Ga-Ram Lee),임병주(Byung-Ju Lim) 한국태양에너지학회 2023 한국태양에너지학회 학술대회논문집 Vol.2023 No.4

듀이의 문제해결과 비판적 사고의 관계

최석민 ( Seok Min Choi ) 한국교육철학회 2004 교육철학 Vol.25 No.-

The purpose of this study is to analyze the interrelationship between Dewey`s reflective problem-solving and critical thinking The conclusions are as follows Above all, even though Dewey believed the generalizability of critical thinking, It`s not logically natural to take It as a method of teaching. In Dewey`s view, the notion of methods isolated from subject-matter is responsible for the false conceptions of discipline and interest. Secondly, the it`s useless to tell the relationships of inclusion between problem-solving and critical thinking in that, as usual, researchers on this issue are inclined to analyze them by their own perspectives. So, in tins research, after examining both conceptions through the medium of reflectivenes, the conclusion is that they are co-extensive in their usages. Thirdly, Ennis urged that Dewey`s view on thinking is totally subjective, psychological one in that the inquirer believes what he wants to believe. But the characteristics of Dewey`s reflective inquiry are far tram in Dewey claimed that one should acquire the ability to supplement the narrowness of his experience by utilizing the experiences of others It means what Ennis called `Dewey`s subjectivism` could be considered as much the same objective efforts as Ennis does in the practical thinking process In conclusion, granted that Dewey was not a servant of subjectivism and the general principles on critical thinking could be changable according to the contexts, the infusion model of education might be successfully adopted as one of the dominant approaches in teaching thinking

창의성 교육의 원리탐색: 몰입의 원리

최석민 ( Seok Min Choi ) 한국교육철학회 2004 교육철학 Vol.26 No.-

A common approach of creativity seems to have been that, after being fully conceptualized, creativity can be cultivated. But creativity can be achieved by meeting the conditions of the idealistic problem-solving or by living the processes of the immersion. Dewey seems to indicate exactly this point when he says that the first stage of experience called thinking is experience. Experience as interest seems to be the context for the activation of creativity. But it may not be that experience is for creativity; rather, creativity for experience. So, Creativity seems not something to be handed down but practiced. It may not be forced but lured. That is because, in Dewey`s view, the qualities of immersion and creativity could be identical, in that both have the same attributes of the good life. So to speak, immersion is the additional name of a state "fully involved in the very process of purpose orientated activity", it could make possible the creative re-construction of one`s present belief system. Hallman`s research on Dewey`s concept of the creativity and Csikszentmihalya`s in-depth analysis of the ninety-one exceptional individuals support it. As Dewey said, unending growing-striving-growing-striving continuation makes us more ideal creative citizen.

송전선로에 있어서 Mutual Coupling을 고려한 디지털 거리계전기의 신뢰도 향상

최석민(Choi Seok-min),이재규(Lee Jae-gyu),유석구(You Seok-Ku) 대한전기학회 1997 대한전기학회 학술대회 논문집 Vol.1997 No.7