http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
이정현,정도현,오승진,정재필 한국마이크로전자및패키징학회 2018 마이크로전자 및 패키징학회지 Vol.25 No.4
Recently, electric semiconductors became an issue because of efficient use of energy and compaction of electronics. Silicon electric semiconductors are difficult to put into it because of its physical limitations. Hence, the study of WBG (Wideband Gap) semiconductors like SiC and GaN began. These devices received attention because it can be miniaturized and worked at high temperatures over 300oC. WBG MOSFET electric semiconductors can show performance like silicon IGBT. This can solve the current problem of IGBT tail. The current study shows the technical principles and issues related to SiC and GaN power semiconductors. WBG devices can achieve high performance compared to silicon, but its performance can’t be fully utilized because of lack in bonding technology. Therefore, this review introduces research on WBG devices and their packaging issues.
이정현,김해동,고광희 한국항공우주학회 2015 한국항공우주학회 학술발표회 논문집 Vol.2015 No.4
인공위성과 지상 안테나 사이의 통신은 지상안테나와 인공위성 사이의 통신 가시권 내에, 전송데이터의 크기 및 전송 속도를 고려한 시간만큼을 지상 안테나에서 Support 함으로써 이루어진다. 다양한 임무를 가진 인공위성 및 지상 안테나가 증가함에 따라, 가시권 충돌이 발생되며, 충돌에 대해 해결하는 알고리즘을 필요로 하게 된다. 가시권 충돌 문제는 Support time 을 가시권에 할당하는 Task scheduling problem 으로 변환 가능하다. 이를 위해서는 기구적 모델링 및 모델링을 기반으로 하는 최적화 알고리즘에 대한 설계가 필요하다. 본 연구에서는 최적화의 추계적 접근법중의 하나인 유전 알고리즘을 이용하여, 다중 위성의 가시권 충돌 해결에 대한 방법론을 제시하였다. The communication between satellites and ground antennas is achieved by ground antenna support considering data size and transmission rate during visibility. As the number of satellites having individual mission increased, the visibility conflict is occurred. Therefore, the algorithm for solving the problem is needed. Visibility conflicts can be converted into a task scheduling problem, which requires the design of the mechanical model and optimization modeling based on it. Genetic algorithm, one of the stochastic optimization approaches, is used for proposing the visibility conflict resolution methodology.
이정현 대한신생아학회 2012 Neonatal medicine Vol.19 No.2
In addition to antibiotic therapy, the administration of supportive care is of utmost importance in sepsis deteriorating to septic shock. Close attention to cardiovascular, respiratory, fluid and electrolyte, hematological, renal and metabolic/nutritional support is essential to optimize the outcome. Firstly, fluid resuscitation is important to attain appropriate heart rate, blood pressure, and refill time. In case of nonresponse to fluid resuscitation, inotropes are used to increase cardiac output, and to improve perfusion of the tissues. Ideally, vasoactive agents, including epinephrine, should be administered by a secure central venous route, but in an emergency,it may be infused through a peripheral route. To improve the imbalance between the need for oxygen and consumption,early intubation and mechanical ventilation should be considered. In newborns with inadequate urine output, hepatomegaly, rale,and 10% weight gain, despite other supportive cares, dialysis or continuous renal replacement therapy should be performed, while on the extracorporeal membrane oxygenation circuit. Central venous access and arterial pressure monitoring are recommended in infants with fluid-refractory shock. Hemodynamic support directed to goals of mixed venous saturation, and cardiac index in newborns is associated with improved survival and neurologic function.
이정현,최수진,고광희 한국항공우주학회 2015 한국항공우주학회 학술발표회 논문집 Vol.2015 No.4
국내에서는 2020 년 달 탐사를 목적으로 기본 연구를 진행 중에 있다. 달 탐사선이 지구 달 전이궤도에 진입하기 전 지구 대기 궤도에 머무르면서, 궤도 결정을 하게 된다. 지구와 달 사이의 궤도 정보는 지상에서 원격 계측 명령을 기반으로 계산이 이루어지며, 계산된 궤도 정보는 탐사선에 송신된다. 하지만, 심우주 통신 상의 제약 조건에 의해, 궤도 정보는 최대한 압축된 형태로 보내져야 한다. 본 논문에서는 B-spline 을 기반으로 하여, 달 탐사선 궤도 데이터의 압축에 대해서 연구하고자 한다. In Korea, the primary research for the moon exploration in 2020 has been studied. Before entering the lunar transfer orbit, the exploration ship is stayed in the parking orbit. The Orbit trajectory between the Earth and moon is calculated in the ground based on telemetry of the ship. However, the orbit trajectory information must be compressed as much as possible due to the visibility constraint on the deep space communication. In this paper, we proposed orbit data compression procedure based on B-spline.