• 대한수학회지
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• 제52권5호
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• pp.891-906
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• 2015

In this work we analyze a postprocessing scheme for improving the guaranteed error bound based on the equilibrated fluxes for the P1 conforming FEM. The improved error bound is shown to be asymptotically exact under suitable conditions on the triangulations and the regularity of the true solution. We also present some numerical results to illustrate the effect of the postprocessing scheme.

• Transactions on Control, Automation and Systems Engineering
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• 제3권1호
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• pp.27-31
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• 2001

In this paper, we consider the guaranteed cost filtering design method for time-varying delay system with parameter uncertainties by LMI(Linear Matrix Inequality) approach. The objective is to design a stable guaranteed cost filter which minimizes the guaranteed cost fo the closed loop systems in filtering error dynamics. The sufficient conditions for the existence of filter, the guaranteed cost filter design method, and th guaranteed cost upper bound are proposed by LMI technique in terms of all finding variables. Finally, we give an example to check the validity of the proposed method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.366-370
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• 2003

This paper is on weighted model reduction using structurally balanced truncation. For a given weighted(single or double-sided) transfer function, a state space realization with the linear fractional transformation form is obtained. Then we prove that two block diagonal LMI(linear matrix inequality) solutions always exist, and it is possible to get a reduced order model with guaranteed stability and a priori error bound. Finally, two examples are used to show the validity of proposed weighted reduction method, and the method is compared with other existing methods.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.125-129
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• 1987

The stability margin of the LQ regulator is investigated in the time domain. it is shown that the same guaranteed gain margin as that of the frequency domain analysis can be obtained with simple assumptions for the continuous time systems. It is also shown that the allowable modelling error bound can be expressed in terms of system matrices and Riccati equation solution. Guaranteed qain. margin and the allowable modelling error bound for the discrete time systems are also obtained by the similar procedures. In this case, through the some examples, the gain margin is shown to be less conservative than the frequency domain analysis result.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.836-841
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• 1993

For a class of discrete-time nonlinear systems, an iterative learning control method is proposed and a sufficient condition is derived for the convergence of the output error. The proposed method is shown to be less sensitive to modelling errors and the uniform boundedness of the output error is guaranteed even in the presence of initial state errors. It is illustrated by simulations that the actual output converges to a desired output within the tolerance bound and convergence performance is improved by the presented method.

• 전기전자학회논문지
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• 제13권1호
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• pp.11-18
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• 2009

In this paper, the stability of second order uncertain systems with regulation of PID type controllers is analyzed by using Lyapunov second method for the first time in the time domain. The property of the stability of PID regulation servo systems is revealed in sense of Lyapunov, i.e., bounded stability due to the disturbances and uncertainties. By means of the results of this stability analysis, the maximum norm bound of the error from the output without variation of the uncertainties and disturbances is determined as a function of the gains of the PID control, which make it enable to analyze the effect resulted from the variations of the disturbances and uncertainties using this norm bound for given PID gains. Using the relationship of the error from the output without variation of the uncertainties and disturbances and the PID gain with maximum bounds of the disturbances and uncertainties, the robust gain design rule is suggested so that the error from the output without the variation of the disturbances and uncertainties can be guaranteed by the prescribed specifications as the advantages of this study. The usefulness of the proposed algorithm is verified through an illustrative example.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권11호
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• pp.650-653
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• 2005

In this paper, adaptive high-order neural network controller(AHONNC) is adopted to control an induction servomotor. A algorithm is developed by combining compensation control and high-order neural networks. Moreover, an adaptive bound estimation algorithm was proposed to estimate the bound of approximation error. The weight of the high-order neural network can be online tuned in the sense of the Lyapunov stability theorem; thus, the stability of the closed-loop system can be guaranteed. Simulation results for induction servomotor drive system are shown to confirm the validity of the proposed controller.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.903-905
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• 2003

In this paper, adaptive high-order neural network controller(AHONNC) is adopted to control of an induction servomotor. A algorithm is developed by combining compensation control and high-order neural networks. Moreover, an adaptive bound estimation algorithm was proposed to estimate the bound of approximation error. The weight of the high-order neural network can be online tuned in the sense of the Lyapunov stability theorem; thus, the stability of the closed-loop system can be guaranteed. Simulation results for induction servomotor drive system are shown to confirm the validity of the proposed controller.

• 제어로봇시스템학회논문지
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• 제7권6호
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• pp.465-470
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• 2001

This paper considers a new weighed model reduction method using block diagonal solutions of Lyapunov inequalities. With the input and/or output weighting function, the stability of the reduced order system is guaranteed and an a priori error bound is proposed. to achieve this after finding the solutions of two Lyapunov inequalities and balancing the full order system, we find the reduced order systems using the direct truncation and the singular perturbation approximation. The proposed method is compared with other existing methods using numerical examples.

• 응용통계연구
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• 제15권1호
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• pp.187-199
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• 2002

표본의 크기가 작아 검정 통계량의 근사분포의 정확성이 의심스러울 때, 정확검정이 종종 사용된다. 정확검정의 장점은 1종의 오류 확률이 항상 유의수준보다 작거나 같음을 보장해 준다는 것이다. 본 논문에서는 정확검 정을 만드는 여러방법, 계산 알고리듬, 그리고 상업용 소프트웨어를 살펴보겠다. 그리고 정확검정에서 얻어지는 exact p-value와 원래 우도(true likelihood)에서 얻어지는 true p-value와의 관계도 살펴보겠다.