http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
FR4 PCB면적과 Via-hole이 LED패키지에 미치는 열적 특성 분석
김성현,이세일,양종경,박대희,Kim, Sung-Hyun,Lee, Se-Il,Yang, Jong-Kyung,Park, Dae-Hee 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.3
In this study, the heat transfer capability have been improved by using via-holes in FR4 PCB, when the LED lighting is designed to solve the thermal problem. The thermal resistance and junction temperature were measured by changing the dimension of FR4 PCB and size of via hole. As a result, when the dimension was increased initially, the thermal resistance and junction temperature was decreased rapidly, the ones was stabilized after the dimension of 200 $[mm^2]$. Also, the light output was improved up to maximum 17% by formation of via-hole and expansion of dimension in FR4 PCB. Therefore, the thermal resistance and junction temperature could be improved by expansion of PCB dimension and configuration of via-hole ability.
국립공원 관리를 위한 해양생태계 장기 모니터링 프로그램의 발전 방향
이채린(Chae-Lin Lee),유재원(Jae-Won Yoo),정병관(Byungkwan Jeoung),김창수(Chang-Soo Kim),안동식(Dong-Sik Ahn),김성태(Sungtae Kim),성은주(Eun-Ju Sung),김성현(Sung-Hyun Kim),정수영(Su-Yeoung Jeong),박영석(Young-Seuk Park) 국립공원연구원 2021 국립공원연구지 Vol.12 No.2
생태계 변화의 모니터링은 효율적 생태계 관리를 위한 기초 정보 수집을 위해 중요한 과정이다. 많은 생태 현상과 그 과정은 오랜 시간에 걸쳐 진행되므로 국립공원의 지속적인 보전 및 효율적 관리를 위해 생태계 모니터링은 장기적으로 이루어질 필요가 있다. 본 연구는 국내외 장기 모니터링 프로그램 사례 분석을 통해 성공적인 장기 모니터링을 위한 방법으로써, 최적화된 모니터링 설계, 표준화된 운용방안 마련, 인적 자원 및 DATA 관리 체계 수립, 안정적인 재정 마련 및 후속지원 등을 제시하였다. 이를 바탕으로, 현재 10년 넘게 수행되고 있는 ‘HS호 유류유출 사고 해역 장기 모니터링 프로그램’의 발전 방향으로 적응형 모니터링 방식이 적용된 표준화된 프로토콜의 정립, QA/QC와 지속적인 자료 관리, 조사 항목의 연계성 강화 등의 구체적 방안을 제안한다. Monitoring ecosystem changes is an important process for collecting basic information for ecosystem management. Since many ecological phenomena and their processes take place over a long period of time, it is necessary to conduct long-term monitoring of ecosystems for the continuous conservation and efficient management of national parks. This study suggested an optimized monitoring design, standardized operation plan, human resource and data management system, stable financial preparation and follow-up support as methods for successful long-term monitoring through case analysis of domestic and foreign long-term monitoring programs. Based on this, it proposes specific measures such as establishing a standardized protocol with adaptive monitoring methods, continuous data management with QA/QC, and strengthening the linkage of investigation items in the development direction of the “HS oil spill accident long-term monitoring program” that has been conducted for more than a decade.
김성현(Sung-Hyun Kim),정재호(Jaeho Chung),백동천(Dong-Cheon Baek),박종원(Jong-Won Park) 한국산학기술학회 2019 한국산학기술학회논문지 Vol.20 No.2
굴삭기에 부착되는 유압 브레이커는 건물의 파괴 및 분해, 도로 포장재의 파손, 채석장에서의 암석 파단 등에 사용되고 있는 부착작업기의 일종의 건설 장비이다. 따라서 유압브레이커의 성능은 주로 충격량 및 충격 효율에 의해 평가되며, 이는 제조사 및 사용자 모두에게 중요한 요소이다. 본 논문에서는 건설 현장에서 주로 사용되는 20톤급 유압브레이커를 대상으로 상용 프로그램인 SimulationX를 사용하여 유압밸브 및 피스톤의 수압 면적 또는 작동 조건에 따라 유압 브레이커의 충격량 예측을 위한 모델링 및 해석을 진행하였다. 또한, 모델링 및 해석의 신뢰성을 확인하기 위하여 기존 실험 연구의 결과를 통하여 비교 및 검증하였다. 본 연구 결과는 제작 이전의 설계 단계에서 유압 브레이커의 충격량을 예측하고 충격량 향상을 위한 파라미터 연구에 도움이 될 것으로 본다. 또한 제조사 측에서는 본 논문의 결과를 통하여 유압 브레이커의 충격량을 미리 예측함으로서, 시행 착오 방지를 통하여 개발 시간 및 비용을 절감할 수 있을 것으로 예측한다. A hydraulic breaker attached to an excavator is a kind of constructuion equipment which is used for the disassembling of buildings, crashing road pavement, breaking rocks at quarry and etc. Therefore, the performance of the hydraulic breaker is mainly evaluated by the impact quantity and impact efficiency, which is an important factor for both the manufacturer and the user. In this paper, modeling and simulation for the prediction of the impact of the hydraulic breaker was conducted according to hydraulic pressure area and operating conditions of the hydraulic valve and piston using the commercial tools SimulationX for the 20ton hydraulic breaker which is mainly used in construction site. In order to verify the reliability of modeling and simulation, the results of previous experimental studies were compared and verified. The results of this study are expected to be useful for predicting the impact of the hydraulic breaker at the design stage before manufacturing and for studying parameters for improving the impact quantity. In addition, the manufacturer predicts that the development time and cost will be reduced through trial and error prevention by predicting the impact of the hydraulic breaker through the results of this paper.
김성현(Sung-Hyun, Kim),박종원(Jong-Won, Park),이기천(Gi-Chun, Lee),백민혁(Min-Hyeok, Baek),김재훈(Jae-Hoon, Kim) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.5
A truck that can lift the lid of the loading box using hydraulic or pneumatic cylinders. It is called Wingcar in the related industry in the wingbody vehicle by the name which derives from the appearance that the loader cover is opened like a wing In the domestic market, large-sized commercial vehicles with 2.5 tons or more produce about 60.000 units a year, and 30.000 are produced as wing-body vehicles, about 50%. It is known that it is common in Asia, and it is hard to see it in Europe and North America where the curtain side method is mainstream. It is known that the market size of the hydraulic cylinders for wing body automobile is about 10 times as large as the domestic market for the domestic companies to enter the Japanese market. The seal and packing of cylinder produced in Korea, due to the characteristics of maintain the function for a long-term once it is installed and it is difficult to maintenance through exchange, it should be careful in the design. More than 95% of domestic cylinder seals are manufactured using global brands such as BUSAK, MERKEL and NOK, which is a stumbling block to cost reduction. The hydraulic cylinder rod eye has a process of finishing the deformed roundness by welding the rod eye after the rod roughing and post-processing. Comparing the shape of the load eye. the strain of each part according to the thurst of the hydraulic cylinder for the wing body was checked and compared, and the cylinder load eye suitable for the use environment was selected.
김성현(Sung-Hyun Kim),박상규(Sang-Gyu Park) 한국교정복지학회 2020 교정복지연구 Vol.0 No.66
In this study, a study was conducted to explore the factors that affect Self-esteem and Frustration on Youth s Suicidal Ideation. The subjects in this study were 689 Youth s in G city. The Self-esteem scale, the Frustration endurance scale, and the Suicidal Ideation scale were used as the survey tools, and t-test, correlation analysis, and multiple regression analysis were used as the analysis method. Looking at the results of this study, first, according to the gender. Self-esteem and Frustration were found to have a significant correlation with Youth s Suicidal Ideation. Second, Self-esteem was found to have a significant effect on Youth s Suicidal Ideation. Third, it was found that Frustration had a significant effect on Youth s Suicidal Ideation. Through this study, the implications of Youth s Suicide factors and Suicide prevention measures were discussed. 이 연구는 자아존중감과 좌절감이 청소년들의 자살생각에 미치는 요인 탐색하기 위해 연구가 진행되었다. 본 연구대상은 G시 소재 청소년 689명이었다. 조사도구로는 자아존중감척도, 좌절인내력척도, 자살생각척도를 사용하였고, 분석방법으로는 t-검증, 상관분석, 중다회귀분석을 실시하였다. 본 연구의 결과를 살펴보면 첫째, 성별에 따라 자아존중감, 좌절감, 자살생각 등이 유의미한 차이가 있는 것으로 나타났다. 둘째, 자아존중감이 청소년의 자살생각에 유의미한 영향을 미치고 있었다. 셋째, 좌절감이 청소년들의 자살생각에 유의미한 영향을 미치는 것으로 나타났다. 끝으로 본 연구를 통해 청소년들의 자살요인과 자살 예방대책을 마련하는 데 시사점을 논의하였다.
김성현(Sung-Hyun, Kim),박종원(Jong-Won, Park),이기천(Gi-Chun Lee),김재훈(Jae-Hoon, Kim) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.5
The Shear used as attachment for construction machinery, is a device for cutting H beam and steel using shear force. It is used as a selective work device for construction machine such as excavator and is used in cutting work such as scrap iron and H beam structure. It is a reality that requires reliability in the related industries. The method of testing the reliability of Shear is as follows: breaking force test, open width measurement test, arm operation test, turning operation test, low temperature test, high temperature test, humidity and water test, impact test, pressure test, turning life test, But there is no standard for Shear. As a new type of device, it has been difficult to secure the reliability of a product suitable for the actual condition, and the result of the life test has not ben a test capable of securing data for evaluating reliability. To solve the above problems. it is necessary to standardize the reliability evaluation standard of Shear used as a selective work device for a construction machine. Therefore, in order to improve the reliability of Shear, which plays an important role in the field of construction and earth – moving machinery in new marketability, this study has developed a reliability evaluation technique.