http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
전자패키지 신뢰성 예측을 위한 최적 구간중도절단 시험 설계
권대일,신인선,Kwon, Daeil,Shin, Insun 한국마이크로전자및패키징학회 2015 마이크로전자 및 패키징학회지 Vol.22 No.2
Qualification includes all activities to demonstrate that a product meets and exceeds the reliability goals. Manufacturers need to spend time and resources for the qualification processes under the pressure of reducing time to market, as well as offering a competitive price. Failure to qualify a product could result in economic loss such as warranty and recall claims and the manufacturer could lose the reputation in the market. In order to provide valid and reliable qualification results, manufacturers are required to make extra effort based on the operational and environmental characteristics of the product. This paper discusses optimal interval censoring design for reliability prediction of electronic packages under limited time and resources. This design should provide more accurate assessment of package capability and thus deliver better reliability prediction.
권대일,최명진,이승현 사단법인 인문사회과학기술융합학회 2016 예술인문사회융합멀티미디어논문지 Vol.6 No.5
The instability of the North Korea regime, which generates both crises and opportunities in the unification of Korean peninsula, requires understanding and support of the international community. As armistice prolongs, however, the problem of excess obsolete ammunition and surplus ammunitions which will backlog after unification has arisen as both domestic and international concern. This study proposes an effective obsolete ammunitions demilitarization method which is applicable to integration policy in the military dimension. In order to propose an optimal ammunition demilitarization of a unification Korea. First, we derived the possible difficulties in the demilitarization of conventional ammunition. Second, we analyzed the current status of domestic and foreign ammunition demilitarization. Third, we analyzed the level of technology in domestic and foreign ammunition demilitarization. Conclusively, as an environment friendly ammunition demilitarization policy of the unification Korea, we propose the prospect of such munitions demilitarization industry and the joint construction plan of ammunition demilitarization facilities. 북한 체제의 불안정성으로 위기와 기회가 공존하고 있는 현 시점에서 한반도 통일을 위해서는 한국의 독자적인 노력과 국제사회의 이해와 지지가 필요하다. 하지만 분단이 장기화됨에 따라 노후된 탄약과 통일 시 적체될 잉여 탄약은 국내뿐만 아니라 국제적인 문제점으로 부각되고 있다. 이에 따라, 본 연구에서는 군사적 차원에서 통합정책과 관련하여 남북한에 산재되어 있는 노후 탄약을 비군사화 시킬 수 있는 효율적인 방안을 제시하였다. 통일 한국의 탄약비군사화 최적 정책방향 제안을 위해 첫째, 재래식 탄약의 비군사화 간에 발생할 수 있는 문제점을 도출하였으며 둘째, 국내·외 탄약비군사화 정책 및 현실태를 분석하고 셋째, 국내·외 탄약비군사화 기술 수준 분석을 하였다. 이를 근거로 통일한국의 산재되어 있는 노후탄약에 대한 친환경 탄약 비군사화의 효율적인 정책방향으로 정책적 지원 및 사업화 방향, 사업전망 및 수익성 분석 결과, 탄약 비군사화 사업 방향, 남북 협력 사업으로 탄약비군사화 시설의 건설 방안을 제안하였다.
Effect of Humidity Changes on Dimensional Stability of 3D Printed Parts by Selective Laser Sintering
권대일,박은주,하상호,김남훈 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.9
Across many industries, additive manufacturing, also known as 3D printing, is being recognized more and more as an innovative manufacturing technology for the next generation. The automotive industry, especially, has paid huge attention to additive manufacturing, and actively applies it to their design, research, development and manufacturing processes. Selective laser sintering (SLS) in additive manufacturing is emerging and popular, and is often used to produce jigs and fixtures for cost benefits and efficiency in the manufacturing industry. However, the application of additive manufacturing is still limited due to the lack of dimensional stability of 3D printed parts associated with changes in temperature and humidity. This paper examines the effect of humidity changes on the dimensional stability of 3D printed parts made by the SLS process. The test results demonstrated changes in relative humidity may result in design specification violation in terms of dimensional requirement while in use.
권대일(Dae Il Kwon),정영기(Young Gi Jeong),조한샘(Han Saem Cho),박현남(Hyun Nam Park),김동열(Dong Yul Kim),박성수(Sung Soo Park),고한서(Han Seo Ko) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11
A period of winter has shortened and a period of summer has lengthened in Korea because .the climate has become a subtropical climate lately, which is contrary to a temperate climate in past years. Furthermore, a discomfort index is getting higher in summer because of high humidity. Therefore, the use of an air conditioner has increased steadily and the electric usage in summer has highly risen annually. Since this situation is unavoidable to live in Korea, it is required to find efficient methods to develop the air conditioners. One of the methods which was attempted in this study was an improvement of the efficiency for a room air conditioner(RAC) by redesigning the outlet blade. The best design has been selected in this study by examining the change of mass flow rate and direction of the cold air for the improved efficiency after redesigning the outlet blade. A commercial software, FLUENT, has been used to analyze the phenomena. Finally, an existing model has been compared with the redesigned model to confirm the improved efficiency.