• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.365-367
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• 1998

This paper shows the form of the optimal solution and how to minimize energy of train driving control. In this paper we consider the case where a train is to be driven by manual operation mode along a straight level track, and with speed limits. Using the constrained optimal technique(Lagrange Function & Kuhn-Tucker equations), we constructed optimal train driving strategy.

• The Transactions of the Korean Institute of Power Electronics
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• v.2 no.1
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• pp.12-25
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• 1997

본 논문은 PNGV 계획에 따른 차세대 전기자동차의 개발을 위하여 고주파 교류 전력분배 시스템을 적용하여 이용할 수 있는 추진력 장치의 구현 가능성에 대한 조사 연구이다. 실행 가능한 관점에서 전력 분배와 에너지원의 결합이 쉽게 이루어 질 수 있고 변환이 가능한 여러 가지 형태의 시스템이 비교 검토되었으며, 현재 기술 수준으로 보아 가까운 장래에 실현 가능한 최적의 시스템 구성은 배터리와 내연기관엔진 및 유도전동기를 이용하는 하이브리드형이 제시되었다. 각 시스템의 원활한 전력수급과 운전특성을 위하여 단상 고주파 교류 전력분배 제어기법을 적용하였으며, 이 시스템의 타당성을 입증하기 위하여 시스템 구성에 따른 모델링과 컴퓨터 시뮬레이션을 실시하였다. 이 결과 차세대 전기자동차용으로 제시된 고주파 교류 전력분배에 의한 하이브리드형 추진력 시스템이 가능하며 운전특성도 우수함을 보여주었다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.568-570
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• 2005

광대역 망에서 범용 TCP를 사용하는 경우 최대 전송 윈도우의 크기가 제한되어 가용한 망 자원이 낭비된다. 이를 해결하는 일반적인 방법은 윈도우 스케일 옵션을 사용하는 것인데 이 경우 송신측의 응용를 수정해야 하는 단점이 있다. 본 논문에서는 이를 해결하기 위하여 송신측을 수정하지 않고 전송 윈도우의 크기를 증가시키는 방법을 제안한다. 이 방법에서는 송수신측 사이에 있는 Snoop 게이트웨이가 망의 상태와 수신측의 처리 능력을 동적으로 파악하여 최적의 윈도우 확대 계수를 결정하고, 이 계수에 상응하는 수의 응답 패킷을 송신측에 전송하여 전송 윈도우 크기가 확대된 효과를 얻는다. 특히, 이 방법은 서로 다른 특성을 갖는 망이 snoop 게이트웨이를 사용하여 2-way 세그먼트 방식으로 연동된 환경에서 부가적인 비용없이 단대단 시맨틱을 유지하면서 성능을 향상시킬 수 있다.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1131-1133
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• 1996

In this paper, we consider the mixed $L_1/H_{\infty}$ problems of finding internally stabilizing controllers which minimize the peak-to-peak gain of a certain closed loop transfer function with $H_{\infty}$-norm constraint on other closed loop transfer function(or vise versa). This problem is a useful framework for designing a controller with the norm constraints upon time and frequency domain. We formulate the mixed $L_1/H_{\infty}$ problem as LMI problems by using the reachable set. This paper offers the sufficient condition for the existence of suboptimal state feedback controller, and shows that suboptimal solution can be obtained by solving a finite-dimensional convex optimization and a line search.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.129-134
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• 1987

In this paper, "Revised two-level costate prediction method" is developed to optimize the quadratic performance of a class of nonlinear dynamic systems. To show the merit, of this algorithm, the proposed algorithm is compared With "The new prediction method" and "Two-level costate prediction method". Advantages of this algorithm are illustrated by applying it to three examples, turbine generator system, fermentation Process, power control system in nuclear reactor.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.214-216
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• 1998

This paper presents the analysis on the voltage problems of Korea electric power system and efficient voltage control actions, when contingencies are considered. This analysis is based on the developed voltage' control techniques. It uses the reactive power-voltage nonlinear characteristics. Therefore, efficient voltage control actions can be obtained. Principal control actions of the program are mainly switched shunt capacitor and generator voltage regulating. This is tested on Korea real power system in future year.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.232-234
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• 1998

In this paper, we are considered various possible disturbance conditions in order to design controller, $H_{\infty}$ optimal controller is successfully designed to control in such as situations. To do this, we are determined weighting function and design parameter $\gamma$ to method of trial and error by Glover-Doyle algorithm. To compare with $H_{\infty}$-PSS and conventional-PSS which is applied in nominal system and load variations, the dynamic characteristics of $H_{\infty}$-PSS controller was verified which has a good response.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.497-504
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• 2003

An optimal design method for hybrid structural control system of building structures subject to earthquake excitation is presented in this paper. Designing a hybrid structural control system nay be defined as a process that optimizes the capacities and configuration of passive and active control systems as well as structural members. The optimal design proceeds by formulating the optimization problem via a multi-stage goal programming technique and, then, by finding reasonable solution to the optimization problem by means of a goal-updating genetic algorithm. The process of the integrated optimization design is illustrated by a numerical simulation of a nine-story building structure subject to earthquake excitation. The effectiveness of the proposed method is demonstrated by comparing the optimally designed results with those of a hybrid structural control system where structural members, passive and active control systems are uniformly distributed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.1
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• pp.167-171
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• 2019

This paper is to consider an issue on the way to initialize the integrator in PID roll controller. A performance index including the 2 norms of roll angle and control signal is introduced to regulate initial roll angle and roll rate in an efficient way. And then we suggest the optimal value to initiate the integrator in PID roll controller by minimizing the performance index. The proposed method shows its effectiveness by showing a demonstrative design example.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.304-306
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• 2007

In this paper, we presents a scheme for the parameter estimation and optimal control scheme for apparatus of container crane system. For parameter estimation, first, we construct the open loop of the container crane system and estimate its parameters based on input-output data, a real-coded genetic algorithm(RCGA) and the model adjustment technique. The RCGA plays an important role in parameter estimation as an adaptive mechanism. For controller design, state feedback gain matrix is searched by another RCGA and the estimated model. The performance of the proposed methods are demonstrated through a set of simulation and experiments of the experimental apparatus.