신경회로망에 의한 전동기 결함 진단

최원호(WONHO CHOI),민성식(SEONGSIK MIN),조규복(KYUBOK CHO) 대한전기학회 1991 대한전기학회 학술대회 논문집 Vol.1991 No.11

레이노 현상의 진단적 접근

최원호 ( Wonho Choi ),김현숙 ( Hyun-sook Kim ) 대한내과학회 2019 대한내과학회지 Vol.94 No.5

Raynaud's phenomenon (RP) is a reversible vasospasm that is aggravated by cold or emotional stress. Before confirming RP, it is essential to consider other possible causes including compressive neuropathy, sensori-neuropathy, thyroid disease, hematologic conditions and offending drugs. RP is typically characterized by the three-step color change that turns pallor (white), cyanosis (blue), and then erythema (red) of reperfusion. Once RP is diagnosed, it is important to determine whether it is primary or secondary RP. To distinguish primary from the secondary RP, the specialized tests performing in clinical practice are antinuclear antibody (ANA) and nailfold capillary microscopy (NFC). The combination of ANA and NFC is most helpful for discriminating secondary RP due to autoimmune rheumatic disease. Thereby, normal findings of NFC in primary RP distinguished from secondary RP should be understood. Patients with primary RP usually improves with symptomatic treatment focused on lifestyle modification and patient education, but those with secondary RP should be treated together with associated disease or causes. (Korean J Med 2019;94:431-437)

극대면적 UV-NIL 장비 개발

최원호(Wonho Choi),신윤혁(Yoon hyuk Shin),강인구(Ingoo Kang),임홍재(Hong Jae Yim),장시열(Siyoul Jang),정재일(Jay Il Jeong),이기성(Kee Sung Lee),임시형(Si-Hyung Lim) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.5

A UV Nano Imprint Lithography (UV-NIL) machine has been developed for micro/nanoscale patterning in an extremely large area like ~300×400 ㎟, To get high pattern fidelity, residual layer thickness uniformity, and an air bubble free layer in the large area, the UV-NIL machine has several main components including a silicon rubber uniform pressurizer, a large area UV-LED module, a vacuum pump, etc. Contact and structural analyses have been performed using commercial FEM packages like LS-DYNA and ANSYS. The developed machine has been tested and its performance indices such as pattern fidelity, residual layer thickness uniformity, etc have been measured.

예비 과학 교사 대상의 실험 수업에서 문제 발견 및 해결 경험의 효과

최원호 ( Choi Wonho ) 부산대학교 과학교육연구소 2017 교사교육연구 Vol.56 No.1

본 연구에서는 문제 발견 및 해결 경험을 강조한 실험 수업을 사범대 재학 예비 과학 교사들에게 실시하였다. 문제 발견 및 해결 경험을 강조한 실험 수업에 참여하면서 학생들은 연구 문제를 새롭게 설정하고 그에 맞는 실험 방법을 설계하는 경험, 연구 문제에 근거하여 결론을 작성하는 경험을 가졌다. 실험 수업 후, 참여 학생들은 기존 형식대로 실험 보고서를 능숙하게 작성하면서도 실험 수업 과정에서 문제 발견 및 해결을 어려워하는 학생과, 문제 발견 및 해결에 익숙하게 사용하여 실험 보고서를 작성하는 학생으로 구분되었다. 이 연구의 실험 수업에 참여한 학생들은 이전 형식의 실험 수업과 문제 해결을 강조한 본 연구의 실험 수업에 대한 느낌이 많이 달랐다고 응답하였다. 학생들은 문제 해결을 강조한 본 연구의 실험 수업에서 이론과 실제가 다름을 알게 되어 과학의 잠정성을 이해하는 기회를 가졌고, 새로운 연구 문제를 도출하고 탐구 과정을 설계하는 경험을 통해 문제 해결 능력 향상의 기회를 가졌다고 응답하였다. 연구에 참여한 학생과 교수자는 문제 발견 및 해결 경험을 강조한 이런 형태의 실험 수업이 예비 과학 교사의 과학적 소양 함양에 효과적일 것이라고 응답하였다. In this research we executed an experiment-based science class focused on the experiences of problem finding and solving for the apprentice science teacher. Students who joined the experiment-based class learned how to create a new inquiry problem, develop a new inquiry process, and how to write a conclusion based on the inquiry problem. After the experiment-based class, half of the students were could generate inquiry reports with the form as usual but had difficulty in creating a problem and problem solving during the experiment-based class. On the other hand, the other half of the students were successful at creating problem and solving and could write inquiry reports. Students who joined this study responded that the style of the experiment-based class of this study was different to their previous experiment-based classes. They responded that they had a choice to understand the changeability of science by recognizing that theory was different from real life and they also had a choice to increase the ability of problem solving through the experience in which they made new inquiry problem and new inquiry process in this experiment class. Students and instructor who joined this study responded that experiment-based class focused on the experiences of problem creation and problem solving like this would be effective to increase scientific literacy of apprentice science teachers.

레이저 원격 용접기술 적용을 위한 차체 설계기술 및 용접지그 개발

최원호(Wonho Choi),이재수(Jaesoo Lee),김대근(Daegeun Kim),박기영(Kiyoung Park) 한국자동차공학회 2007 한국자동차공학회 지부 학술대회 논문집 Vol.- No.-

The objective of the research which it sees applies Laser Remote Welding technique in mass production line to be, from data base securities against the material variable, a process variable from Laser welding processes and the mechanical quality of the welding region it leads and body plan techniques and welding jig techniques of optimum about under establishing site to apply. And to keep up the body parts quality of top, simultaneously decrease of the material and weight because decrease of welding places, the mobile path of the robot against the assembly parts of complicated form, the product and the welding gun avoid with each other interference cause by reduced a production cycle time, also to diminish the duplication investment of body assembly equipment and the increase of assembly line caused by, it confront in a strategy module of productivity improvement and the automobile part, with the result that it strengthens the competitive power of the enterprise.

Reference Evapotranspiration Calculator Software를 이용한 기상관측소 기준증발산 추정

최원호(Choi Wonho),최민하(Choi Minha),오현제(Oh Hyunje),박주양(Park Jooyang) 대한토목학회 2010 대한토목학회논문집 B Vol.30 No.2B

Reference Evapotranspiration Calculator Software (REF-ET)는 ASCE 및 FAO 기준증발산량을 포함한 총 17개의 FAO Penman-Monteith (PM) 방정식의 연산을 동시에 수행할 수 있는 프로그램으로서, 본 연구에서는 REF-ET에 대한 상세한 소개와 함께 기상관측소의 관측지료를 이용하여 REF-ET의 효용성을 논하였다. REF-ET는 각종 PM 방정식들에 대한 시일 월 단위 모의와 지역적 특성의 반영 및 결측자료에 대한 보정 등이 가능하다. REF-ET를 이용하여 서울 기상관측소의 29년간 증발산량을 모의한 결과, 일복사량에 주로 좌우되는 FAO24-Rd 식과 1957-Makk 식의 상관계수가 각각 0.89와 0.88로 높게 나타났으며, 이는 소형증발접시를 이용한 기준증발산량 관측값이 공기 동력학적 증발량만을 주로 반영하기 때문인 것으로 사료된다. 또한 RMSE/bias 분석을 통해 기준증발산 방정식들에 의한 계산값이 증발접시로부터의 기준증발산량에 비해 다소 과대평가되는 현상을 나타내었으나, 이 경우에도 1957-Makk 식이 가장 정확한 것으로 나타났다. 일단위 시계열 분석시 1957-Makk 식은 여름철의 증발산량을 저평가하는 경향을 나타내었으나, 전체적으로 1.06 ㎜/day의 오차로 증발산량을 모의 가능하였다. 차후 기상관측자료의 정확도를 높이는 연구들과 REF-ET를 병행한다면, 해당 지역 및 기간에 대한 증발산량 모의 및 관련 특성인자를 파악하는 연구에 활용도가 높을 것으로 기대된다. The Reference Evapotranspiration Calculator Software (REF-ET) supports computational guidelines for the reference evapotranspiration using seventeen FAO Penman-Monteith (PM) equations simultaneously such as the ASCE and FAO standardized forms. The REF-ET can conveniently consider missing data predictions and regional site characterizations, when reference ET is computed on monthly, daily, and hourly time steps. The applicability of the REF-ET was estimated to simulate the reference ET using hourly weather data from Seoul weather station for 29 years. The result found that the FAO24-Rd and 1957-Makk equations closely concerned with solar radiation parameter which were the most highly correlated to reference ET computed by pan coefficient. In addition, the 1957-Makk equation was identified as the most correct computational method for reference ET by analysis of bias and root mean square error. The 1957-Makk equation could predict the reference ET within the error of less than 1.06 ㎜/day, though all the other equations tended toward overestimation of predicting the reference ET in comparison with refecence ET of pan. The results of this study suggest that the REF-ET will be applicable to support reference ET estimation for a variety of field condition and time-scale.

극대면적 UV-NIL 공정에서의 균일 가압 시스템 개발

최원호(Wonho Choi),신윤혁(Yoon-Hyuk Shin),여민구(Minku Yeo),임홍재(Hong Jae Yim),신동훈,장시열(Siyoul Jang),정재일(Jay Il Jeong),이기성(Kee Sung Lee),임시형(Si-Hyung Lim) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

Ultraviolet-nanoimprint lithography (UV-NIL) is promising technology for cost effectively defining micro/nano scale structure at room temperature and low pressure. In addition, this technology is fascinating because of it's possibility for high-throughput patterning without complex processes. However, to acquire good micro/nano patterns using this technology, there are some challenges such as uniformity and fidelity of patterns, etc. In this paper, we have focused on uniform contact mechanism and performed contact mechanics analysis. The dimension of the flexible sheet to get adequate uniform contact area has been obtained from contact mechanics simulation. Based on this analysis, we have made a uniform pressurizing device and confirmed its uniform pressurized zone using a pressure sensing paper.

샌드위치 판재의 성형성을 고려한 차체 부품의 개발

최원호(Wonho Choi),최보성(Bosung Choi),이덕영(Dug Young Lee),황우석(Woo Seok Hwang) 한국자동차공학회 2012 한국 자동차공학회논문집 Vol.20 No.4

구조 공진회피에 의한 변압기 소음저감

崔沅鎬(Wonho Choi),金振(Jin Kim),石皓壹(Hoil Suk) 대한전기학회 2005 전기학회논문지C Vol.54 No.12

CAE를 통한 하이브리드 용접 후 차체부품 변형예측

최보성(Bosung Choi),황재현(Jaehyun Hwang),백일기(Ilki Baek),최원호(Wonho Choi),이덕영(Dugyoung Lee),안장호(Jangho Ahn) 한국자동차공학회 2009 한국자동차공학회 부문종합 학술대회 Vol.2009 No.4

In recent years, laser-arc hybrid welding has begun to be adopted for assembly welding of automotive bodies and parts, because hybrid welding process can weld lapped steel sheets that have a lager pap than is possible with laser welding. But if the gap is wide, burn-through occurs, and, if the gap is excessive, the two sheets cannot be welded together. For this reason, the gap is very important for hybrid welding. In this paper, to predict the twist deformation by hybrid welding when brackets are welded in B pillar of passenger car, the residual stress using CAE is analyzed and the deformation results of CAE is compared with welded panel.