http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
오석진 ( Seokjin Oh ),이창민 ( Changmin Lee ) 사단법인 아시아문화학술원 2021 인문사회 21 Vol.12 No.4
2019년 7월 일본의 대한국 수출규제가 시행된 지 2년이 경과하였다. 이에 수출규제의 영향을 보여주는 많은 연구보고서 등이 작성되었으나, 서로 상반된 결과가 제시되어 혼란을 빚고 있다. 본 연구에서는 이러한 논란의 원인을 명확히 함과 동시에, HS코드 기반의 관세청 수출입무역통계를 통해 수출규제 3품목의 수입동향을 분석하였다. 그 결과, 불화수소의 경우 수출규제의 영향으로 수입량이 감소했음을 직접적으로 확인할 수 있었다. 그리고 포토레지스트와 불화폴이미드의 수입량은 전략물자의 특성상 정확히 집어낼 수 없었지만, 현재 양산에는 사용되지 않는 품목이므로 수출규제의 영향이 제한적임을 알 수 있었다. 이에 정부 차원에서 실시하고 있는 수입기업 조사에 관한 통계자료를 공개할 것을 제안함으로써, 일본의 수출규제 영향에 대한 냉철한 현실인식이 필요함을 강조하였다. It has been two years since the export restrictions were enforced in July 2019. Many research reports showing the impact of export restrictions have been published, but conflicting results were revealed. To clarify the cause of this controversy, this study analyzed the import trends of 3 export restrictions items through HS code based trade statistical data of the Korea Customs Service. As a result, In the case of hydrogen fluoride, it was directly confirmed that the import volume decreased due to the impact of export restrictions. In addition, although the import volume of photoresist and fluorinated polyimide could not be accurately pinpointed due to the characteristics of strategic items, it was found that the impact of export restrictions was limited as they are not currently used for mass production. In this regard, it is proposed to promote a correct understanding of the impact of Japan's export restrictions by presenting the statistical data on the import company survey conducted at the government level in detail.
고체추진 추력조절 시스템에 적용가능한 감압률 모델링 방법론 연구
윤지수,허준영,오석진,Yoon, Jisu,Heo, Junyoung,Oh, Seokjin 한국추진공학회 2022 한국추진공학회지 Vol.26 No.4
The depressurization rate in a thrust variable solid rocket motor is the major factor that has the greatest influence on the thrust termination performance. In this study, the depressurization rates range of model solid rocket motor was identified and major factors affecting the depressurization rate were found. It is important for actual system design to understand the depressurization rate of the system that can satisfy the target performance as well as the extinguishing characteristics of the solid propellant. The methodology for obtaining the depressurization rate model in this study is considered to be applicable to the optimal design of the thrust terminable propulsion system.
공압시험용 플러그 노즐의 핀틀 형상 및 작동압력에 따른 유동 특성 분석
김정진(Jeongjin Kim),오석진(Seokjin Oh),허준영(Junyoung Heo),이도형(Dohyung Lee) 한국추진공학회 2019 한국추진공학회지 Vol.23 No.3
The thrust control calculation according to the operation of plug nozzle for cold air test and the analysis of the flow characteristics of the pintle shape and operation pressure are performed. The numerical computation was verified by comparing the flow structure and the coefficient of thrust with the experimental data. It was confirmed that the nozzle throat was formed at the design position on each pintle shape, and thrust control up to 1:8 was achieved only by the stroke change. Finally, although the aerospike nozzle is autonomous, it is unfavorable in the under_expansion condition, if it is designed for a very low nozzle pressure ratio.