• Journal of Institute of Control, Robotics and Systems
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• v.19 no.7
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• pp.583-586
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• 2013

We consider discrete-time LTI (Linear Time-Invariant) systems with constant input delays. The input delay is modeled by a first-order PdE (Partial difference Equation) and a backstepping transformation is employed to design a predictor feedback controller. The backstepping approach results in the construction of an explicit Lyapunov function, with which we prove the exponential stability of the closed-loop system formed by the predictor feedback. The numerical example demonstrates the design of the predictor feedback controller, and illustrates the validity of the exponential stability.

• Journal of Industrial Technology
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• v.29 no.B
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• pp.9-15
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• 2009

In the case of traditional binary encoding technique, it takes long time to converge the optimal solutions and brings about complexity of the systems due to encoding and decoding procedures. However, the ROGAs (real-coded genetic algorithms) do not require these procedures, and the k-means clustering algorithm can avoid global searching space. Thus, this paper proposes a new approach by using their advantages. The proposed method constructs the multiple predictors using the optimal differences that can reveal the patterns better and properties concealed in non-stationary time series where the k-means clustering algorithm is used for data classification to each predictor, then selects the best predictor. After selecting the best predictor, the cluster centers of the predictor are tuned finely via RCGKA in secondary tuning procedure. Therefore, performance of the predictor can be more enhanced. Finally, we verifies the prediction performance of the proposed system via simulating typical time series examples.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.117-121
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• 1990

The control process involving pure time delays presents a continuing challenge to the control system engineer. The nonlinear nature of the delay which can be introduced into the system make the use of conventional control algorithms a poor prospect. The Smith Predictor was developed to alleviate this problem. Unfortunately the quality of control achieved with the Smith Predictor is known to be sensitive to modelling errors. Only recently have researchers attempted to quantify the Smith Predictor controller's robustness to modelling errors. In several studies stability boundaries were plotted as functions of errors in parameters. But the research results address the question of performance of Smith Predictor controllers, In this paper, the Rule based Expert Systems for performance improvement of the Smith Predictor controller are developed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.12
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• pp.1704-1709
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• 2014

In order to increase the performance of multi-core system processor architectures, the multi-thread branch predictor which speculatively fetches and allocates threads to each core should be highly accurate. In this paper, the perceptron based multi-thread branch predictor is proposed for the multi-core processor architectures. Using SPEC 2000 benchmarks as input, the trace-driven simulation has been performed for the 2 to 16-core architectures employing perceptron multi-thread branch predictor extensively. Its performance is compared with the architecture which utilizes the two-level adaptive multi-thread branch predictor.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.10
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• pp.1023-1029
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• 2014

In this paper, we propose an SPDR (Smith Predictor for Disturbance Reduction) scheme to improve the temperature control by reduction of the disturbance in ROT process with measurement delay. The proposed controller is a combination of Astrom's modified Smith predictor with a disturbance reduction controller and a grey predictor. The grey prediction is used to calculate the inverse of the measurement delay and to predict future variations and tendencies of system output. The simulation results demonstrate the successful performance of the proposed disturbance reduction controller and enhance the robustness of the proposed control scheme.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2317-2319
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• 2000

This paper presents a feedback controller for compensation time delay in the distributed control systems. In using network, controllers and sensors are distributed on a communications network, there exist time delays on communication lines between the system components. So, we deal with the controller using Smith predictor controller design issue for such systems. Particularly compensated for the time delay of the plant or controller involved integrator using Modified Smith predictor. Simulation and the results show the good performance for the modified Smith predictor control systems.

• 전기의세계
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• v.31 no.1
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• pp.59-67
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• 1982

This paper suggests easy stabilization methods for linear time-varying systems with delay in the state. While existing methods employ the function space concept, the methods introduced in this paper transform the delay systems into the non-delay systems so that the well known methods for finite dimensional systems can be utilized. Particularly the intervalwise predictor is introduced and shown to satisfy an ordinary system. Control laws stabilizing the non-delay systems satisfied by this predictor will be shown to at least pointwise stabilize the delay systems with the additional strong possibility of true stabilization. In order to combine two steps of the predictor method, first transformation and then stabilization, an intervalwise regulator problem is suggested whose optimal control laws incorporate the intervalwise predictor as an integral part and also at least pointwise stabilize the delay systems. Since the above mentioned methods render the periodic feedback gains for time invariant systems the pointwise predictor and regulator are introduced in order to obtain the constant feedback gains, with additional stability properties. The control laws given in this paper are perhaps simplest and easiest to implement.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1730-1734
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• 2005

In this paper, a new Smith predictor controller for a disturbance adding to input side of a time delay plant is proposed. A disturbance observer is obtained to estimate an input disturbance and the new Smith predictor controller to eliminate the effects of a disturbance is designed using the disturbance observer. As a result, the proposed Smith predictor controller can make a steady state error for step input disturbance zero quickly. The effectiveness and the improved performance of the proposed system are verified by computer simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.12
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• pp.2725-2730
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• 2012

In this paper, for improving the H.264/AVC hardware performance, we propose an inter predictor hardware design using a multi reference frame selector and an implicit weighted predictor. previous reference frame are reused for Low Memory Bandwidth. The size of the reference memory in the predictor was reduced by about 46% and the external memory access rate was reduced by about 24% compared with the one in the reference software JM16.0. We designed the proposed system with Verilog-HDL and synthesized inter predictor circuit using the Magnachip 0.18um CMOS standard cell library. The synthesis result shows that the gate count is about 2,061k and the design can run at 91MHz.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2006.06a
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• pp.176-182
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• 2006

본 연구에서는 기존 Bagging Predictors에 수정을 가한 Modified Bagging Predictors를 이용하여 SOHO 에 대한 부도예측 모델을 제시한다. 대기업 및 중소기업에 대한 기압부도예측 모델에 대한 많은 선행 연구가 있어왔지만 SOHO 만의 기업부도예측 모델에 관한 연구는 미비한 상태이다. 금융기관들의 대출심사시 대기업 및 중소기업과는 달리 SOHO에 대한 대출심사는 이직은 체계화되지 못한 채 신용정보점수 등의 단편적인 요소를 사용하고 있는 것에 현실이고 이에 따라 잘못된 대출로 안한 금융기관의 부실화를 초래할 위험성이 크다. 본 연구에서는 실제 국내은행의 SOHO 데이터 집합이 사용되었다. 먼저 기업부도 예측 모델에서 우수하다고 연구되어진 인공신경망과 의사결정나무 추론 기법을 적용하여 보았지만 만족할 만한 성과를 이쓸어내지 못하여, 기존 기업부도예측 모델연구에서 적용이 미비하였던 Bagging Predictors와 이를 개선한 Modified Bagging Predictors를 제시하고 이를 적용하여 보았다. 연구결과,; SOHO 부도예측에 있어서 본 연구에서 제시한 Modified Bagging Predictors 가 인공신경망과 Bagging Predictors등의 기존 기법에 비해서 성과가 향상됨을 알 수 있었다. 제시된 Modified Bagging Predictors의 유용성을 확인하기 위해서 추가적으로 대수의 공개 데이터 집합을 활용하여 성능을 비교한 결과 Modified Bagging Predictors 가 기존의 Bagging Predictors 에 비해 일관적으로 성과가 향상됨을 알 수 있었다.