저온용 무연솔더 조성 개발의 필요성과 대표 조성의 특성

이종현,강남현,이창우,김정한,Lee, Jong-Hyun,Kang, Nam-Hyun,Lee, Chang-Woo,Kim, Jeong-Han 대한용접접합학회 2006 대한용접·접합학회지 Vol.24 No.2

전자 패키징 Interconnect 소재로의 카본 나노튜브의 활용

이종현,Lee, Jong-Hyun 한국마이크로전자및패키징학회 2009 마이크로전자 및 패키징학회지 Vol.16 No.3

Carbon nanotube(CNT)s have been considered as one of the most unique materials due to the their superior mechanical, thermal and electrical properties. Therefore, numerous studies have been performed for the utilization of CNTs. This review article focuses on the recent research trends on the utilization of CNTs for new interconnect materials in electronics packaging. Major contents mentioned are the direct interconnection technology using CNTs and the main properties of polymer/CNTs composite materials. This article is aimed at the reviewing of important results from the recent studies and providing the straightforward understanding of the results through the mutual analysis and a industrial viewpoint.

건설현장 관리자 안전 리더십이 근로자 안전 태도와 행동에 미치는 효과 : 자기 고양 편향을 중심으로

이종현,문광수,Lee, Jong Hyun,Moon, Kwangsu 한국안전학회 2020 한국안전학회지 Vol.35 No.2

This study examined the effects of perceptual differences of safety leadership between managers and workers on workers' safety attitudes and behavior in two construction sites. In addition, the mediating role of safety attitude between safety leadership and safety behavior across discrepancy level of safety leadership. This study was conducted on two first-tier construction companies within the 100th place in 2019. Two companies were similar in size(100 - 150 billion won) and process from the basement frame finishing stage to start of the ground structure of apartment. In A Site, 40 managers and 73 workers, 42 managers and 77 workers in B site participated the survey on managers' safety leadership, and workers' safety attitude and behavior. The results showed that there was no significant difference between the safety leadership scores assessed by the manager and workers at site B. However, the safety leadership scores assessed by the managers were significantly higher than that by the workers at site A. The workers' safety attitudes and behaviors at site B were higher than those of workers at site A. Moreover, Site B was significantly higher in the effects of safety leadership on safety behavior than Site A. At site B, safety leadership had a significant influence on safety behavior even after controlling the safety attitude of workers. At site A, safety leadership had no significant effect on safety behavior after controlling safety attitude. These findings suggest that there is managers' self-serving bias on safety leadership in site A and that this bias of leadership can negatively affect workers' safety attitude and behaviors. In addition, it can be seen that if the self-serving bias on safety leadership occurs, the manager's safety leadership has less influence on workers' safety behavior.

솔더 나노입자를 사용한 TSV Interconnection 기술

이종현,윤종호,현창용,Lee, Jong-Hyun,Yoon, Jong-Ho,Hyun, Chang-Yong 대한용접접합학회 2011 대한용접·접합학회지 Vol.29 No.3

흰쥐를 이용한 실험적 맥락막신생혈관 모델에서 유리체강내 양막 주입의 효과

이종현,정재림,홍사민,고형준,Jong Hyun Lee,Jae Lim Chung,Samin Hong,Hyoung Jun Koh 대한안과학회 2008 대한안과학회지 Vol.49 No.7

Purpose: To evaluate the effects of an intravitreal amniotic membrane (AM) injection on a rat model of laser-induced choroidal neovascularization (CNV). Methods: Intravitreal injection of AM (12.5 µg/mL) into the left eyes and phosphate-buffered saline into the fellow eyes of 15 rats was performed immediately after laser injury. At week 2, after angiography, the rats were sacrificed, and histopathologic analysis was performed. Angiographic and histopathologic assessments of the effects of AM injection on CNV growth were compared between the two groups. Results: CNV thickness was found to have increased more in the AM treatment group (141.54±8.12 µm) than in the experimental control group (65.23±16.90 µm) (p=0.010). Conclusions: Intravitreal AM injection demonstrated histopathologic pro-angiogenic properties in a rat model of CNV. J Korean Ophthalmol Soc 49(7):1154-1158, 2008

MGrid Portal : 분자 시뮬레이션 그리드 포탈

이종현(Lee Jong Hyun0 Kim),김동욱(D.W. Lee),이건영(K.Y. Jeong),정갑주(K.J. Hwang),황선태(S.T. Park),박형우(H.W.) 한국정보과학회 2004 한국정보과학회 학술발표논문집 Vol.31 No.1A

그리드 컴퓨팅은 다양한 이기종 분산 컴퓨팅 환경에서 다양한 소프트웨어들에 대한 설치, 운영, 업그레이드, 유지보수 등이 요구된다. 이러한 환경에서 응용 소프트웨어(특히, 레가시 소프트웨어) 지원은 매우 어려운 작업이다. 웹 포탈 기술은 이러한 문제에 대한 효과적 대안이다. 그러나 웹 포털의 경우 다양한 사용자 인터페이스 제공이 난해하여 긴밀한 사용자와 컴퓨터간 상호작용이 요구되는 응용과학 분야 연구에 적용이 어렵다. MGrid 포탈은 BT/NT분야에서 광범위하게 사용되는 연구기법인 분자 시뮬레이션을 지원하도록 설계된 그리드 포탈 시스템으로 분자 시뮬레이션 작업들에 대한 상세한 모니터링 및 통제 기능을 지원하도록 설계되어 있다.

운행 중인 2-Arch 터널의 피난연결통로 신설을 위한 중앙벽체 굴착에 관한 연구

이종현,Lee, Jong-Hyun 한국재난정보학회 2021 한국재난정보학회 논문집 Vol.17 No.3

연구목적: 기시공되어 현재 운행 중인 2-Arch 터널에 대하여 피난연결통로 신설의 필요성이 대두되고 있다. 이에 본 연구는 중앙벽체 굴착에 따른 터널 및 벽체 거동 분석과 안정성 분석에 목적을 두고 있다. 연구방법: 2-Arch 터널과 피난연결통로의 이론적 배경을 설명하고, 3차원의 유한요소 수치해석을 통하여 터널 및 벽체의 거동을 집중적으로 분석하였다. 다양한 지반 조건을 변수로 하여 암반 등급에 따른 매개변수 해석을 수행하였으며, 중앙벽체의 변위와 응력을 집중적으로 분석하였다. 연구결과: 중앙벽체 굴착 시 개구부 중앙에서 가장 큰 침하량을 보였으며, 응력은 첫 번째 굴착 시 가장 크게 발생하였다. 또한 개구부 양 상단에서 응력집중 현상이 발생함을 알 수 있었으며, 허용응력 개념을 고려한 안정성 검토 결과 허용응력을 초과하는 것으로 나타났다. 결론: 터널의 천단변위는 허용기준치 내로 안정성을 확보하였지만, 발생응력은 허용기준치를 초과하는 것으로 나타나 시공 시 적절한 보강공법을 적용하여 갑작스런 응력 해방에 대한 방지가 필요할 것으로 사료된다. Purpose: There is a need to construct an evacuation passageway for the 2-Arch tunnel, which has been constructed and is in operation. Therefore, it aims to analyze tunnel and center wall behaviour and stability due to excavation of the center wall. Method: We describe the theoretical background of 2-Arch tunnel and evacuation passageway, and focused on analyzing the behaviour of tunnel and wall using 3-dimensional finite element analysis. Parametric analysis according to rock rating was performed with various ground conditions, and the displacement and stress of the center wall were intensively analyzed. Result: With the center wall excavation, the largest amount of settlement was shown in the center of the opening, and the stress was greatest during the first excavation. In addition, it was shown that stress concentration occurred at the top of both openings, and stability reviews considering the concept of allowable stress showed that it exceeded the allowable stress. Conclusion: Although the displacement of the tunnel has secured stability within the allowable standard, the generated stress is found to exceed the allowable standard, so it is necessary to prevent sudden stress release by applying appropriate reinforcement methods during construction.

타이어-휠가드 공간의 음장모드와 고주파성 로드노이즈의 상관성 연구

이종현,구요천,이진모,Lee, Jong Hyun,Ku, Yo Cheon,Lee, Jin Mo 한국음향학회 2016 韓國音響學會誌 Vol.35 No.4

타이어와 휠가드 사이의 공간은 타이어 패턴음의 전달경로가 된다. 본 논문에서는 타이어-휠가드 공간에서 발생하는 음향현상을 음장모드 분석과 휠 가드 표면에서 음압분포 가시화를 통해 규명하였다. 타이어 패턴음 저감을 위해 음향학적 댐퍼 역할을 수행하는 캐비티를 휠가드 표면상에 적용하였다. 실내소음은 2 dB(A) 감소하였는데, 본 연구에서 다룬 소음저감방법은 완성차 단계에서 원가/중량의 증가없이 실내음질을 개선하는 효과적인 방안이 될 것이라고 판단된다. The space between tire and wheel guard acts as a path for tire pattern noise transmission. In this study, acoustic phenomenon occurring in the tire-wheel guard space is investigated using acoustic mode analysis and visualization of the sound pressure distribution over the wheel guard surface. We introduced a cavity over the wheel guard surface to reduce the tire pattern noise, where the cavity acts as an acoustic damper. The interior noise was reduced by 2 dB(A), and the noise control measures treated in this study may provide an efficient method to improve interior sound quality without increasing cost and weight at the final stage of the vehicle development.

미용전공 여대생과 비전공 여대생의 체형인식, 신체만족도 및 식습관 비교 연구

이종현,김민선,오주환,Lee, Jong-Hyun,Kim, Min-Sun,O, Ju-Hwan 동아시아식생활학회 2007 동아시아식생활학회지 Vol.17 No.4

This study was carried out to investigate perceptions of body image, body satisfaction, and dietary habits of beauty art major and non-major college students in Gyeonggi province. A total of 312 self-administered questionnaires (beauty art majors=145; non-majors=167) were analyzed. The means for height, weight, and BMI were 161.7 cm, 51.4 kg and 19.7, respectively. There were more majors who were underweight according to BMI classification than non-majors. Sixty-six percent of the subjects had previous weight control experience, and there was no significant difference between the majors and non-majors. The mean score for current body image was 4.61 out of a possible 9 points in the majors, which was significantly lower than 4.95 in the non-majors, and their perception of an ideal body image was thinner than their current body image. Those with more weight control experience had currently heavier perceptions of their body. The mean score for body satisfaction was 2.60 out of a possible 5 points, which was lower than the mean score for their attitudes toward the importance of their bodies. The mean score for dietary habits was 2.80 out of a possible 5 points, and there was no significant difference with dietary habits according to weight control experience or BMI classification. In both the majors and non-majors, there was a significant positive correlation between BMI and perception of current body image (p<0.001, p<0.001), and a negative correlation between BMI and body satisfaction (p<0.01, p<0.001). In the major students, there were significant positive correlations between dietary habits and body satisfaction (p<0.01), and attitudes toward the body importance (p<0.05); therefore, the greater their body satisfaction and body importance, the higher their scores for dietary habits.

공간패널모형을 이용한 국내 초미세먼지 농도에 대한 분석

이종현,김영민,김용구,Lee, Jong Hyun,Kim, Young Min,Kim, Yongku 한국데이터정보과학회 2017 한국데이터정보과학회지 Vol.28 No.3

초미세먼지 (particulate matter 2.5, $PM_{2.5}$)는 분진의 입경이 2.5 이하의 보다 작은 크기의 미세한 입자들을 말하는데, 미세먼지와 달리 대기 중에서 제거가 어렵고 기도나 코 점막에서 걸러지지 않으며, 호흡 시 폐포까지 직접 침투하기 때문에 장기간 노출될 경우, 폐 기능 감소, COPD (chronic obstructive pulmonary disease) 증가, 폐암 발생증가가 있다고 알려져 있다. 현재 국내외에서 초미세먼지에 대해 다양한 연구가 이루어지고 있는데, 초미세먼지의 농도는 기상인자 (풍속, 강우량, 일사량 등)에 영향을 받는 것으로 알려져 있으며, 이산화질소, 오존, 이산화황, 미세먼지 등 대기물질의 농도에도 영향을 받는 것으로 알려져 있다. 특히 우리나라는 점차 증가하고 있는 자동차 수나 오염원으로 인한 초미세먼지외에도 중국으로부터 유입되는 초미세먼지 또한 고려되어야 하는 대상이므로 기상인자 중 풍향과 풍속 또한 어느 정도 큰 영향을 미칠 것으로 판단되며 인접 지역에 대한 영양 또한 고려되어야 할 것이다. 본 연구에서는 초미세먼지 농도에 영향을 미치는 유의한 대기물질 및 기상자료와 초미세먼지 농도의 지역적 특성을 고려한 공간자기상관 행렬에 기초한 공간패널모형을 소개하였고 이를 서울 25개 구에서 관측된 초미세먼지 자료에 적용하였다. 또한 초미세먼지와 대기오염물질의 농도를 통해 서울시에서 발생한 호흡기 질환 환자 수를 분석하여 그의 위해성을 확인하였다. It is well known that the air quality of 92% of the world is known to exceed the standard of WTO and the death caused by air pollution is almost 6 million per year. The $PM_{2.5}$ concentration in Korea is the second most serious among the OECD countries following Turkey. Since the $PM_{2.5}$ has a direct effect on the respiratory system, it has been actively studied in domestic and foreign countries. But current research on the $PM_{2.5}$ is limited in weather factor or air pollutants. In this paper, we consider the influence of spatial neighbor with weather factor or air pollutants using spatial panel model. We applied the proposed method to 25 borough of Seoul in Korea. The result shows a significant effect of spatial neighbor on the $PM_{2.5}$ concentration fields.