표면처리에 따른 평기어 치의 표면거칠기 변화에 관한 연구 ( A Study on the Surface Roughness Variation of Spur Gear Teeth as a function of the Surface Treatment )

유장열,이성철,권오관,정태형 한국트라이볼로지학회 1991 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.7 No.2

전산유체해석과 실측을 이용한 도심내 미기후 특성에 대한 연구

유장열,박민우 한국공간구조학회 2023 한국공간구조학회지 Vol.23 No.1

Microclimate analysis was conducted through actual measurement according to land use status in urban, and CFD analysis was conducted to analyze and predict the microclimate characteristics of urban, and compared and analyzed with the actual measurement results. It was measured in high-rise areas and parks, and the temperature of the park area was 0.4 to 0.6℃ lower, and the relative humidity was 1.0 to 3.0% higher. The correlation coefficient was obtained by comparing the results of the computational fluid analysis with the results of the computational fluid analysis at the actual location located within the CFD analysis area for validation. The seasonal correlation coefficients are all higher than 0.8, so it is judged that they can be applied to microclimate analysis in urban area. The computational fluid analysis was divided into three areas (low-rise, low and high-rise, and high-rise) centered on the A2 point. On average, the low-rise area was 0.1 to 0.4% higher than the high-rise area. In the low and high-rise area and high-rise area, the pith of buildings are wide, so the airflow is smooth, so it is judged that the temperature is relatively low.

扁桃摘出術 및 Adenoid 切除術의 臨床的 考察 : 특히 그 適應症에 關하여

柳章烈 충남대학교 의과대학 지역사회의학연구소 1984 충남의대잡지 Vol.11 No.2

102 cases of tonsillectomy and adenoidectomy experienced at the department of otolaryngology Chungnam National University Hospital between Jan. 1981 and Oct. 1984 were reviewed especiall about the indications of each operation. Results were as follows: 1. Most of tonsillectomy and adenoidectomy were performed between the age of 6 and 10 years. 2. 68 cases (67%) of tonsillectomy and adenoidectomy were performed and 26 cases(25%) of tonsillectomy and adenoidectomy with myringotomy were performed. 3. Indications for tonsillectomy and adenoidectomy were frequent sore throat or frequent upper respiratory infection 50 cases(46%), hearing disturbance 22 cases(21%), mouth breathing 20 cases(20?), nasal obstruction 5 cases(5%) and snoring 3 cases(3%).

쌍곡선포물선 대공간 구조물의 측벽개구율에 따른 지붕의 풍압특성

유장열,유기표,You, Jang-Youl,You, Ki-Pyo 한국공간구조학회 2013 한국공간구조학회지 Vol.13 No.1

There can be diverse causes in the destruction of a large space structure by strong wind such as characteristics of construction materials and changes in internal and external wind pressure of the structure. To evaluate the wind pressure of roof against the large space structure, wind pressure experiment is performed. However, in this wind pressure experiment, peak internal pressure coefficient is set according to the opening of the roof in Korea wind code. In this article, it was tried to identify the change of internal pressure coefficient and the characteristics of wind pressure coefficient acting on the roof by two kinds of opening on the side of the structure with Hyperbolic Paraboloid Spatial Structures roof. When analyzing internal pressure coefficient according to roof shape, it was found that minimum (52%) and maximum (30%~80%) overestimation was made comparing to partial opening type proposed in the current wind load. It is judged that evaluation according to the opening rate of the structure should be made to evaluate the internal pressure coefficient according to load.

자율학습 - 음악과

유장열 한국음악교육학회 1986 음악교육연구 Vol.5 No.-

비산물에 대한 지붕 강판의 내충격 성능 평가

유장열,정다와,유기표 대한건축학회 2024 대한건축학회논문집 Vol.40 No.1

연구의 목적은 비산물에 대한 지붕 강판과 같은 외장재의 내충격 성능을 평가하는 것이다. 미국·일본과 같이 허리케인, 태풍에 빈번히 노출되는 국가에서는 이미 비산물에 대한 외장재 내충격 시험을 실시하고 있다. 우리나라 또한 태풍 및 강풍에 의한 외장재 파손 피해가 많이 발생하고 있다. 따라서 비산물에 의한 내충격 시험이 필요하다고 생각한다. 본 연구에서는 해외 기준을 참고하여 내충격 시험 장치를 개발하고 시험 방법을 확립하였다. 또한 지붕강판에 대한 내충격 시험을 실시하여 그 결과를 나타냈다. 시험 결과, 시험체 관통이 일어나는 최소 임계치는 0.35mm 두께의 강판에 D Type 이상의 가격체를 발사하였을 경우이다. 그리고 지붕 강판의 겹침 부위에서는 1.5골 겹침에 가격체 E Type을 발사하였을 때 관통이 발생했다. 이 때 사용된 볼트 간격을 200mm에서 100mm로 변경하여 가격체 E Type으로 시험해본 결과 관통이 발생하지 않았다. This research aims to assess the impact-resistant performance of cladding materials, such as roof steel sheets, against windborne debris. Countries like the United States and Japan, prone to hurricanes and typhoons, routinely conduct impact tests on exterior materials. Korea,facing damage from typhoons and strong winds, also requires evaluating impact resistance through missile tests. This study develops testequipment based on international standards, establishes a test method, and conducts impact resistance tests on roof steel plates. Followingthese tests, penetration occurred when a missile of type D or higher struck the non-overlapping 0.35mm thick steel plate. At overlappingpoints, an impact with a missile of type E was applied to the 1.5 furrow part. In earlier findings, adjusting bolt spacing from 200mm to100mm at overlapping points prevented penetration, even during a missile impact of type E.

공동주택의 저층 필로티 유무에 따른 풍환경 평가

유장열,채명진,유기표 대한건축학회지회연합회 2018 대한건축학회연합논문집 Vol.20 No.1

Wind occurring within high-rise apartment complexes and in the surrounding area causes inconvenience for pedestrians and residents. This “building wind” that occurs between buildings is significantly affected by the shape and layout of the apartment buildings. In this paper, we measured the changes in wind velocity ratio due to placement of piloti on the floor level of different types of apartment complexes, and we assessed the results against several wind environmental criteria. We evaluated the wind environment of the apartment complexes by conducting wind tunnel tests for 16 different wind directions. For the experiment, we used data obtained from the meteorological observatory in the city of Daejeon, where apartment buildings with piloti are common. This experiment demonstrated an increase in wind velocity of up to 80% in the apartment complexes, depending on the building layouts. The presence of piloti reduced this increase in wind velocity by as much as 40%. The reduction in wind velocity due to piloti varied depending on the layout of the apartment buildings. 고층건물 아파트내부와 주변에서 발생하는 바람에 인해 보행자와 거주자에게 불편을 주고 있다. 이러한 건물들 사이에서 발생하는 빌딩풍은 아파트의 형태와 배치등에 많은 영향을 받게 된다. 본 논문에서는 아파트 저층 필로티 유무에 따른 아파트 단지의 다양한 형태별 풍속비의 변화를 측정한후에 풍환경기준과 비교하여 보았다. 아파트 단지내 풍환경 평가를위하여 풍동실험을 하였다. 실험측정풍향각은 16개 방향에 대해서 실시하였다. 실험대상지는 중정층 아파트가 많이 보급되어 있는 대전의 기상대 데이터를 이용하였다. 풍환경 실험결과 아파트 배치에 따라 단지내 풍속이 최대 80%이상 증가를 하였다. 그리고 필로티의 설치는 이러한 풍속증가를 최대 40%이상 감소를 시키고 있었다. 그러나 필로티도 아파트 단지의 배치에 따라 풍속의 감소효과는 다양하게 나타나고 있었다.

표면처리에 따른 평기어 치의 표면거칠기 변화에 관한 연구 ( A Study on the Surface Roughness Variation of Spur Gear Teeth by the Surface Treatment )

유장열,이성철,권오관,정태형 한국트라이볼로지학회 1991 한국트라이볼로지학회 학술대회 Vol.13 No.-

고층 건물의 개구부형상과 단면적의 변화에 따른 풍응답 특성

유장열,장호면,유기표 대한건축학회지회연합회 2017 대한건축학회연합논문집 Vol.19 No.1

최근에 많은 고층건물에 새로운 재생 가능 에너지를 사용하기 위해 풍력 터빈 시스템을 설치하였다. 특히 풍력 발전기를 건물 내에 설치하여 풍력 발전 시스템을 구축하는 것은 안전한 에너지를 확보하기 위한 매력적인 방법이다. 그러나 대부분의 연구는 풍력 터빈의 효율과 바람에 의한 진동의 반응 효과를 다루었다. 풍력 터빈 설치를 위한 공간 준비는 충분히 고려되지 않았다. 본 연구에서는 고층 건물에 풍력 터빈을 설치할 수 있는 개구부의 모양과 단면적에 변화가 있는 건물에서 발생하는 바람에 의한 진동 반응의 특성에 대해 살펴 았다. 실험을 수행하기 위해 9 개의 풍력 모델이 구축 되었다.실험 결과에 따르면 풍속은 C 형> S 형> R 형의 순서로 개구의 형태에 따라 달라진다. 또한 면적이 감소함에 따라 풍속이 증가했다. Recently, many skyscrapers have installed wind turbine systems to use new renewable energy. In particular, building an integrated wind power generation system by installing a wind power generator inside a building is an attractive method to secure safe energy. However, most studies have dealt with the efficiency of wind turbines and the response effects of wind induced vibration; space preparation for wind turbine installations has not been sufficiently considered. This study reviewed the shapes of openings where wind turbines can be installed in skyscrapers and the characteristics of wind induced vibration responses occurring in the building with changes in across sectional area. Nine wind power models were constructed to carry out the experiment. According to the experimental results, wind speed varied with shape of opening in the order C-type>S-type>R-type. Moreover, wind speed increased as the area was reduced.

관통형과 단부형 필로티 천장부의 피크풍압계수 특성 분석

유장열,김근호,채명진,김영문,유기표,You, Jang-Youl,Kim, Geun-Ho,Chae, Myung-Jin,Kim, Young-Moon,You, Ki-Pyo 한국공간구조학회 2018 한국공간구조학회지 Vol.18 No.2

Various pilotis are installed in the lower part of high rise buildings. Strong winds can generate sudden airflow around the pilotis, which can cause unexpected internal airflow changes and may cause damage to the exterior of the piloti ceiling. The present study investigates the characteristics of peak wind pressure coefficient for the design of piloti ceiling exteriors by conducting wind pressure tests on high rise buildings equipped with penetration-type and end-type pilotis in urban and suburban areas. The minimum peak wind pressure coefficient for penetration-type piloti ceilings ranges from -2.0 to -3.3. Minimum peak wind pressure coefficient in urban areas was 30% larger than in suburban areas. In end-type piloti ceilings, maximum peak wind-pressure coefficient ranges from 0.5 to 1.9, and minimum peak wind-pressure coefficient ranges from -1.3 to -3.6. With changes in building height, peak wind pressure coefficient decreases as the aspect ratio increases. Peak wind-pressure coefficient increases with taller pilotis. On the other hand, when piloti height decreases, the absolute value of the minimum peak wind pressure coefficient increases.