• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2004년도 가을 학술발표논문집 Vol.31 No.2 (3)
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• pp.622-624
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• 2004

내부 시스템을 통합하는 비즈니스 관점에서 발전하던 웹 서비스가 모든 가정 내 통신과 가전제품을 연결하는 홈 네트워크와 같은 외부 시스템으로의 적용이 확대되면서 정차 보편화 되어가고 있다. 이런 외부 시스템으로의 적용을 위해서는 웹 서비스와 홈 네트워크 장치 간의 정보를 변환하고 제어하는 미들웨어 개발이 필요하다. 본 논문에서는 홈 네트워크의 자동 탐지 및 제어를 위한 UPnP 표준 기술과 서로 다른 플랫폼이나 언어로 작성된 어플리케이션 통합에 대한 표준 메커니즘을 제공하는 웹 서비스 기술을 이용하여 홈 네트워크나 유비쿼터스 환경에서의 분산 어플리케이션 개발 및 연계를 용이하게 하는 미들웨어를 설계 하고 구현하였다. 이 미들웨어를 임베디드 타입으로 개발함으로써 셋탑박스 또는 가정 내 모든 디바이스들에 내장 형태로 구성이 가능해짐으로 확장성을 제공한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 B
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• pp.497-499
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• 1999

This paper considers enhancing the robustness of a MIMO(Multi-Input Multi-Output) predictive control system. The characteristic polynomial matrix of the closed-loop is shown to consist of two factors $P_c$ and T, where $P_c$ is determined by the tuning knobs of the predictive controller and T is an observer or prefilter polynomial matrix. The robust stability condition is derived in terms of $P_c$ and T. A guideline on the selection of T is then presented for open-loop stable processes.

• 제어로봇시스템학회논문지
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• 제17권8호
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• pp.753-759
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• 2011

The HIV (Human Immunodeficiency Virus) causes AIDS (Acquired Immune Deficiency Syndrome). The process of infection and mutation by HIV can be described by a 3rd order state equation. For this HIV model that includes the dynamics of the mutant virus, we present a parameter estimation scheme using two state variables sporadically measured, out of the three, by employing a genetic algorithm. It is assumed that these non-uniformly sampled measurements are subject to random noises. The effectiveness of the proposed parameter estimation is demonstrated by simulations. In addition, the estimated parameters are used to analyze the equilibrium points of the HIV model, and the results are shown to be consistent with those previously obtained.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.313-316
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• 1989

A steady state analysis of a load commutated current source inverter which is widely used in high voltage - high power induction motor drive systems at present is presented and its related results are discussed. This analysis proposes a method by which we can determine the output capacitor playing a dominant role on the performance of the system. It is shown that the capacitance of output capacitors is mainly dependent on the range of frequencies that the inverter is operated in the load commutated state.

• 대한전기학회논문지
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• 제36권7호
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• pp.484-491
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• 1987

A sufficent condition for the robust control of the adaptive control system is presented under the convergence of the parameters of the adaptive system. The plant in the adaptive control system is a stable system which includes the unmodelled dynamics and can be approximated by a minimum phase system. It is shown that modified structure which Kosut and Friedlander suggested satisfies the sufficient condition more easily than the original structure without modification. It is also shown by computer simulation that the modified structure and/ or the adaptation method using the normalized input and output data or filtered input and output data can improve the robustness of the adaptive control system.

• 대한전기학회논문지:전력기술부문A
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• 제51권11호
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• pp.535-543
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• 2002

Modern power grids are becoming more and more stressed with the load demands increasing continually. Therefore large stressed power systems exhibit complicated dynamic behavior when subjected to small disturbance. Especially, it is needed to analyze special conditions which make small signal stability structure varied according to operating conditions. This paper shows that the relation between small signal stability structure varied according to operating conditions. This paper shows that the relation between small signal stability and operating conditions can be identified well using node-focus point and 1:1 resonance point. Also, the weak point which limits operating range is found by the analysis of resonance condition, and it is shown that reactive power compensation may solve the problem in the weak points. The proposed method is applied to test systems, and the results illustrate its capabilities.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.127-129
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• 2001

CAN 통신은 네트워크 시스템 제어를 통한 각종 산업설비에서 제어 및 자동화 관련 장비들간에 데이터 교환을 위한 통신망으로 널리 사용되고 있다. 이러한 CAN통신을 응용하여 실시간 메시지 송수신이 가능한 시스템을 구성하려면 메시지의 특성분류 및 메시지의 증가에 따른 트레픽 발생을 고려해야 한다. CAN의 제한된 속도에 따른 실시간 메시지 전송의 여부는 데드라인을 통한 메시지 설계로 성능을 보장받고 있다. 하지만 이러한 메시지의 송수신에 있어 단순 CAN네트워크 망에 의존한 설계만으로 메시지의 신뢰성을 보장받을 수 없다. 네트워크 상황에 따른 버퍼를 통한 능동적인 메시지 스케줄링 방법을 통하여 성능효과를 보장받을 수 있는 방법을 제안한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.135-137
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• 2009

Mathematical models for describing the Human Immunodeficiency Virus(HIV) infection can be devised to better understand how the HIV causes Acquired Immune Deficiency Syndrome(AIDS). The HIV models can then be used to find clues to curing AIDS from a control theoretical point of view. Some models take Cytotoxic T Lymphocytes(CTL) response to HIV infection into account, and others consider mutants against the drugs. However, to the best of our knowledge, there has been no model developed, which describes CTL response and mutant HIV together. Hence we propose a unified model to consider both of these. On the basis of the resulting model, we also present a Model Predictive Control(MPC) scheme to find an optimal treatment strategy. The optimization is performed under the assumption that the Structured Treatment Interruption(STI) policy is employed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.154-159
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• 1988

In this paper, a hyperstable cascade control scheme for servo drive systems is proposed to reduce the chattering, which is an undesirable property in discontinuously controlled systems. First, a discontinuously controlled hyperstable MRAC scheme is designed with respect to PI speed control system using only output variables, and then a linear position controller is cascaded. It is shown that the above system is asymptotically stable and the chattering is greatly reduced at a constant speed provided that the disturbance torque satisfies a certain condition.

• 제어로봇시스템학회논문지
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• 제2권3호
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• pp.134-141
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• 1996

In this paper, we formulate the mathematical model for a single-stand rolling mill and design control systems for the thickness control at the exit of roll stand and for the tension control of the strip in the process. We propose a thickness controller based on the Internal Model Control structure which can be an effective application when the frequency components of the thickness deviation of the entry strip are known and, show how it can be appropriately combined with BISRA AGC method for a precise thickness control while maintaining the robustness against the modeling error of the mill modulus. It is illustrated by simulations that the proposed thickness control method gives better performance than existing methods and has the robustness against the modeling error of the mill modulus as well.