• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.260-261
• /
• 2011

현재 한국전력공사 전력연구원은 IEC 61850 패킷 분석이 가능하고 IEC 61850 통신규격 제정기관인 UCA(Utility Communication Architecture)에서 발행된 클라이언트 적합성 시험절차서(Rev 1.1)에 대한 시험모델링이 가능한 클라이언트 전용의 시험시스템 개발을 완료하였다[1-5]. 본 논문은 IEC 61850 클라이언트 적합성 시험 중 변전자동화의 파일 전송시험과 타임서버관한 시험모델링과 사례를 다루고자 한다.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.1388-1389
• /
• 2011

태양광 발전 시스템은 화석연료를 대체하는 가장 대표적인 신재생 에너지이다. 하지만 신재생 에너지는 발전량이 일정하지 않고, 예측 불가능 하다는 단점이 있다. 이를 보완하기 위해서 기존 태양광 발전 시스템에 에너지 저장장치를 붙인 하이브리드 태양광 발전 시스템이 각광받고 있다. 본 논문에서는 리튬-이온 배터리를 모델링하고, 시스템 시뮬레이션을 통해 타당성을 검토한다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.383-388
• /
• 2004

A piezoelectric actuator yields hysteresis effect due to its composed ferroelectric. Hysteresis nonlinearty is neglected when a piezoelectric actuator moves with short stroke. However when it moves with long stroke and high frequency, the hysteresis nonlinearty can not be neglected. The hysteresis nonlinearty of piezoelectric actuator degrades the control performance in precision position control. In this paper, in order to improve the control performance of piezoelectric actuator, an inverse modeling scheme is proposed to compensate the hysteresis nonlinearty problem. And feedforward - feedback controller is proposed to give a good tracking performance. The Feedforward controller is inverse hysteresis model, Nueral network and PID control is used as a feedback controller. To show the feasibility of the proposed controller and hysteresis modeling, some experiments have been carried out. It is concluded that the proposed control scheme gives good tracking performance

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2003.05a
• /
• pp.98-101
• /
• 2003

The purpose of this research is to investigate the hypersonic reactive flow around hyperbolic shaped ballistic launcher, A numerical study was carried out to compare with the experimental results of hyperbolic shaped model, which were tested in a free piston shock tunnel, T3 in ANU. Freestream condition was 98% $N_2$, 2% $O_2$, and total enthalpy was 8MJ/kg. Also this paper used 2-temperature and 1-temperature model to show the difference of them.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1996.05b
• /
• pp.423-428
• /
• 1996

피동형원자로 AP600을 참조발전소로하여 설정된 1000MWe급 대용량 피동형원자로의 계통개념에 대한 안전계통 성능 평가 및 코드의 적용성 평가를 목적으로 RELAP5/MOD3코드를 사용하여 대형냉각재상실사고를 모의 해석하였다. 피동형 안전계통으로 축압기, CMT IRWST를 모델하였으며 가압기에 연결된 1단계부터 3단계까지의 자동감압밸브계통을 모델링 하고 4단계 자동감압밸브계통은 각 루프의 고온관에 연결되어 있는 것으로 모델링 하였다. 피동형 안전계통의 모델이 향상된 RELAP5/MOD3.2와 그 이전의 코드인 RELAP5/MOD3.1의 냉각재상실사고 모의계산결과 원자로내의 압력변화, 노심냉각수 주입유량 및 핵연료 피복재 온도 거동이 거의 유사하게 나타났으며 1000MWe급 대용량 피동형원자로의 안전계통은 냉각재 상실사고시 충분한 노심냉각능력을 가지는 것으로 분석되었다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2001.10a
• /
• pp.52-54
• /
• 2001

최근 웹에서 XML(extensible markup languag) 문서들이 보편화됨에 따라, 기존의 DBMS를 이용하여 XML 문서를 효율적으로 저장하고 관리하는 방법에 대한 연구가 활발히 진행중이다. 이를 위하여 DTD(document type definition)로부터 데이타베이스 스키마를 생성하는 효율적인 방법이 필요하다. 그러나 지금까지는 대부분의 연구가 풍부한 모델링 기능을 제공하는 객체관계형 DBMS 대신에 관계령 DBMS 관점에서 진행되어왔다. 본 논문에서는 객체관계형 DRMS 인 오디세우스를 위한 XML 스키마 생성를 설계하고 구현한다 첫째. DTD로 부터 관계형 데이타베이스 스키마를 생성하는 기존의 방법을 객체관계형 DBMS의 중요한 모델링 기능인 집합 타입과 참조 타입을 이용하도록 수정한다. 둘째, 수정된 방법을 오디세우스 객체관계명 DBMS에 구현한다. 마기막으로, 구현을 용이하게 할 수 있도록 기존의 방법에서 예로서만 기술된 DTD 단순화 방법에 대만 구제적인 알고리즘을 제시한다.

• Journal of Drive and Control
• /
• v.11 no.3
• /
• pp.1-6
• /
• 2014

In forklifts, the machine performance is largely depended on the transmission performance. The aim of this paper is to develop a complete model of transmission control valve (TMV) system of a typical forklift using AMESim simulation tool. By using the developed TMV model, it becomes easy to investigate the system concept, working principle, and performance. In addition, an optimization on the TMV structure can be achieved by using this model with tunable parameters. Simulations have been carried out in a comparison with the actual experiments to verify the model.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.26 no.6
• /
• pp.1-9
• /
• 2022

This study introduces the calculation model of ionization composition and electrical conductivity for metallic plasma for practical application to modeling and simulation of modern electrical detonators. The present model includes the correction for non-ideality of dense plasma conditions which are expected in electrical explosion of bridge in detonators. The computational results for copper plasma show favorable agreement with experimental data for a wide range of plasma temperature and high density conditions and the model is proper for detonator modeling with good prediction accuracy.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.13 no.6
• /
• pp.528-537
• /
• 2002

In this paper, the extended FDTD is used for the analysis of microwave circuits including active elements. Lumped elements such as R, L, C which are inserted into a microstrip line are analyzed with the FDTD lumped element modeling. Parasitic capacitance and inductance could be obtained using network modeling and so it is sure that FDTD lumped element modeling makes it possible to get more accurate data which include parasite components. Moreover, a balanced mixer using two diodes that are modeled by an extended FDTD is designed and the more exact characteristic of the mixer is acquired than in current circuit simulator.

• Korean Chemical Engineering Research
• /
• v.49 no.2
• /
• pp.230-237
• /
• 2011

In this study, the characteristic of fluid flow in the new type lung assist devices has been established using computational fluid dynamics(CFD). For the modeling, the hollow fiber was ignored, and vertical types and tangential types were used for the model. Which was to analyze the flow characteristics of the fluid flow model when there exists 1 and 2 input/output ports, and when the input/output ports is located at the center of the cylinder and at the tangential direction with the cylinder wall. The modeling results showed that it was possible to eliminate no-flow region(stagnant layer) as shown in the vertical type when an inlet and an outlet were installed on the tangential direction of the cylinder as shown in the tangential type. Also, in the tangential type, vortex-type flow appeared as dominant, and it showed a complicated flow not deviated to one side. When the number of input/output was two, there was no deviated flow, and complicated flows were generated all across the tube. From the test result, it was found that input/output of flow was tangential type and complicated flows with no stagnant layer would be generated when there are two inputs/outputs, respectively.