http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Turbulent Drag Reduction and Mechanical Degradation of Polyisobutylene in Kerosene
Lim, Sung Taek,Lee, Kiho,Kim, Chul Am,Choi, Hyoung Jin,Kim, Jae Guen,Jhon, Myung S. 한국공업화학회 2002 Journal of Industrial and Engineering Chemistry Vol.8 No.4
We investigated turbulent drag reduction induced by polyisobutylene molecules dissolved in kerosene and their chain degradation under a turbulent flow. Using a rotating disk apparatus, we found that drag reduction efficiency decreased with time due to mechanical degradation of the polyisobutylene molecules. The theoretical equation for molecular degradation based on midpoint scission in a turbulent flow was found to be well fitted to high concentration polymer solutions in a mildly turbulent flow.
문기호(Kiho Moon),이규백(Gyubaek Yi),임알렉산드르(Alexandr Lim),조영민(Youngmin Cho),김용래(Yongrae Kim),최주엽(Juyeop Choi) 한국해양환경·에너지학회 2021 한국해양환경·에너지학회 학술대회논문집 Vol.2021 No.10
최근 신재생에너지 보급 수단인 수상태양광 발전에 대한 회의적인 목소리가 잇따르고 있다. 새똥 때문에 새만금 태양광발전소 실증 설비가 제대로 가동되지 못하고 있다는 보도가 나오는 등, 태양광 패널 표면 오염 중 조류 배설물에 의한 수상태양광 패널오염으로 인한 태양광 발전시스템 출력감소에 대한 이슈가 대두하였다. 이는 조류 배설물에 뒤덮인 새만금호 시험시설이 설치된 곳이 바다란 지리적 특성·기울기·규모 탓으로 추정되며, 새만금개발청에서 "일부러 악조건서 실험 중"이라는 해명도 내어 놓았지만 외국에서는 음파 및 주기적 소음 유발 장치 등 여러 해결책들을 고려하고 있다. 국내에서도 에너지공단 및 전문가들이 조류와 공존할 수 있는 기술개발의 중요성을 인식하고, 조류를 유인할 수 있는 대체 쉼터 형성과 모듈 프레임에 조류가 앉는 것을 방지하는 방안에 대해 강구하고 있으나 “가장 중요한 것은 친환경적 대안을 찾는 것”이라고 결론짓고 있다. 본 논문에서는 논의되고 있는 이슈에 대한 문제점과 지금까지 제시되었던 내용들을 공유하고자 한다. Currently the attitude to floating offshore photovoltaic(PV) power generation and the ways of transmission of renewable energy is skeptical. It has been reported that the Saemangeum PV demonstration facilities are not operating properly due to bird droppings, among the pollution on the surface of the solar panel. Therefore, the issue of reducing the output of PV system owing to contamination of the floating solar panel by bird dropping has been emerged. This is presumed to be in connection with the geographical characteristics, slope, and scale of the sea where the Saemangeum Lake test facility covered with bird droppings were installed, and the Saemangeum Development Administration has explained that it is "intentionally tested under severe conditions", but foreign countries are considering various solutions such as sound waves and periodic noise-causing devices. The Korea Energy Corporation and experts recognize the importance of technology development that can coexist with birds, and are working on the ways to form alternative shelters that can attract birds and prevent birds from sitting in the module frame, but conclude that "the most important thing is to find Eco-friendly alternatives." In this paper, we would like to share the problems of the issues being discussed and the contents presented so far.
Master-slave Teleoperation Control using Time Delay Control
Hae Jin Lim,Jong Kwang Lee,Hyo Jik Lee,Kiho Kim,E-Sok Kang 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10
A Bridge transported Dual arm Servo-Manipulator (BDSM) was designed to use in a hot-cell at Korea Atomic Energy Research Institute (KAERI). The slave of BDSM can handle a 25 kgf payload object in any posture. The position error resulting from gravity force produces the unnecessary force that the operator does not have to feel. Therefore, gravity force for remote tools or repair equipment must be compensated. Time Delay Control (TDC) is one of the effective and robust control methods when uncertain dynamics or unpredictable disturbances exist. TDC uses past observation of the system’s response which is used to cancel the effect of unknown parameters. TDC is applied for a simple one degree of freedom master-slave system, which can improve the position control performance effectively by compensating for gravity force.