• 한국경영과학회지
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• 제11권1호
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• pp.36-43
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• 1986

In this study, the fuzzy programming is extended to handle various types of membership functions by transformation of the complicated fuzzy programming problems into the equivalent crisp linear programming problems with single objective. It is well-known that the fuzzy programming problem with linear membership functions (i.e., ramp type) can be easily transformed into a linear programming problem by introducing one dummy variable to minimize the worst unwanted deviation. However, until recently not many researches have been done to handle various general types of complicated linear membership functions which might be more realistic than ramp-or triangular-type functions. In order to handle these complicated membership functions, the goal dividing concept, which is based on the fuzzy set operation (i. e., intersection and union operations), has been prepared. The linear model obtained using the goal dividing concept is more efficient and single than the previous models [4, 8]. In addition, this result can be easily applied to any nonlinear membership functions by piecewise approximation since the membership function is continuous and monotone increasing or decreasing.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.1024-1027
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• 1992

This paper deals with design method of the model following servo system in which optimal regulator probelm is used to design the controllers that make the step/ramp response of the plant be keptclose to a specified ideal step/ramp response of the model. The characteristics of this system is robust in the presence of the specified disturbances or the partameter perturbations of the plant. Especially, by direct feedforward compensator from the reference input the steady state offset of plant output response is excluded and the transient response is improved. Examples are give and the results of the design of the model follwing servo systems are verified by the computer simulation.

• 대한공간정보학회지
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• 제5권2호
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• pp.29-43
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• 1997

ITS 구축을 위한 고속도로축 통합최적제어모형은 진입램프미터링, 진출램프전환율 그리고 인접노면가로 g/C비 결정 등 3가지 제어 변수를 동시에 결정될 수 있도록 구축하였다. 또한 실시간 처리가 가능하도록 당초 비선형문제를 선형문제로 전환하기 위해 교통밀도 관계식을 두 개의 선형함수로 축약하고, SLP알고리즘을 사용한 컴퓨터 알고리즘도 제안하였다.

• 한국전기전자재료학회논문지
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• 제17권10호
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• pp.1125-1131
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• 2004

Misfiring is usually observed at high ambient temperature in plasma display panel (PDP). This leads to bad image quality and limits the productivity of PDP industry. In this paper, experimental observations and improvement on the misfiring at high ambient temperature have been studied. In order to reduce the high ambient temperature misfiring different slope of ramp erase pulse corresponding to the temperature are applied. The experimental results show that the suggested method is quite effective for reducing the high temperature misfiring phenomena.

• 대한교통학회지
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• 제14권4호
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• pp.7-29
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• 1996

The optimal solution obtained by a linear programming model is to maximize the ramp inflow rate. It is argued in this paper that the maximization of inflow rate is different from the maximization of outflow rate under congested conditions. Therefore, this paper proposes a systematic searching procedure from a linear programing formulation to a integer programming : first obtain the optimal solution by a linear programming and then adding weight to linear programming then. solve the optimal solution again by integer programming i.e. The proposed method is an interactive approach. Measure of effectiveness by simulation models regards the real time data(O/D, queue, delay, etc), can be utilized in the proposed interactive process.

• 대한전기학회논문지
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• 제43권7호
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• pp.1186-1192
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• 1994

This paper presents an algorithm to design a robust digital model following servo control system in which optimal linear quadratic regulator problem is used to design the control system that make the step/ramp response of the plant kept close to a specified ideal step/ramp response of the model. The quadratic criterion function for a continuous system is used to design the robust digital servo control system. The feasibility of the design technique is shown by the simulation and the proposed method is applied to the speed control of DC servo motor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.423-425
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• 1998

Resonance effects and nonlinear frictions which generate many problems in control system exist in almost all the servo system. therefore, In this paper, the design procedure which employs $H_{\infty}$ control theory after augmenting with two integrators is proposed to track the ramp input. Limit cycles are unavoidable by the effect of interaction between two integrators and Coulomb friction in these system. The describing function is used to check the limit cycles and decide the coefficients of two integrators to minimize the effect of the limit cycles.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.433-439
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• 2004

This paper reports the grid resolution issues on the supersonic mixing simulation inside the engine for future aerospace vehicles. Unstructured finite volume method is used for the simulations. Three types of grids are used, namely, hybrid unstructured grids composed of prism and tetrahedron cells, locally refined grids, and hexahedral grids. Hexahedral grids are used to take advantage of fine distribution naturally behind the edge of the ramp where the vortex is generated. These latter two grids show much improved evaluations of the vortex motion and the mixing of the injected and the main flows.

• 대한전기학회논문지
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• 제45권4호
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• pp.467-473
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• 1996

This Paper presents a new algorithm to solve Dynamic Economic Dispatch problem. Proposed algorithm is composed of two computational modules; one is dispatch, the other adjusting module. In the dispatch module based on the traditional Static Economic Dispatch method, the power dispatch of each unit is calculated. And in case the results of dispatch module violate ramp rate constraints, Lagrange multipliers are adjusted in the adjusting module. Tests and computer results on test systems are given to show the efficiency of the proposed algorithm. (author). 11 refs., 6 figs., 4 tabs.

• 대한기계학회논문집A
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• 제29권1호
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• pp.115-123
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• 2005

This paper presents the development of an algorithm for position control of feed drives in machine tools. The algorithm is constructed through an experimental method based on proportional control with a ramp input. In the first step of designing, a tracking-error curve is generated with the proportional control, and then an error model is decided to reduce the tracking error, Next, the output signal of the error model is added to the current error signal to yield the actuating error signal. The effectiveness of the proposed scheme is confirmed through simulation and experiments.