• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.340-340
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• 2000

This paper aims at deriving an equivalent finite dimensional discrete-time system for H$_{\infty}$ type problem for sampled-data control systems. A widely used ph is based on the lifting technique, but it needs somewhat complicate computation. Instead this paper derives an equivalent finite-dimensional discrete-time system directly from a description of the sampled-data system which is achieved via a closed-loop expression of the worst-case intersample disturbance.

• 한국컴퓨터산업학회논문지
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• 제2권7호
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• pp.967-974
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• 2001

리프팅 기법을 사용하지 않고 최악의 경우에 대한 등가 이산화 절차를 통하여 샘플치 $H{\infty}$ 문제를 다루었다. 이산 문제 특성화를 유도하기 위해서 표준 선형 2차 이론의 결과를 이용하였다. 제안한 방법은 한 번의 행렬 지수함수 풀이만을 필요로 하므로 리프팅 기법에 비해 매우 간단하지만, 리프팅 기법을 사용하여 구한 샘플치 $H{\infty}$ 최적 제어기와의 성능차이가 거의 없었다. 또한, 제안한 방법을 도립진자 모델에 적용하였다

• International journal of advanced smart convergence
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• 제8권1호
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• pp.75-81
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• 2019

Data imbalance problem is common and causes serious problem in machine learning process. Sampling is one of the effective methods for solving data imbalance problem. Over-sampling increases the number of instances, so when over-sampling is applied in imbalanced data, it is applied to minority instances. Under-sampling reduces instances, which usually is performed on majority data. We apply under-sampling and over-sampling to imbalanced data and generate sampled data sets. From the generated data sets from sampling and original data set, we construct a heterogeneous ensemble of classifiers. We apply five different algorithms to the heterogeneous ensemble. Experimental results on an intrusion detection dataset as an imbalanced datasets show that our approach shows effective results.

• 제어로봇시스템학회논문지
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• 제2권2호
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• pp.73-80
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• 1996

This paper proposes a stabilizing controller for the multirate sampled-data systems which have a periodic output measurement scheme. A sufficient condition for maintaining observability in the multirate sampled-data system is derived and a design strategy for disturbance rejection is proposed. The proposed controller has IMC structure, and can be decomposed into the disturbance estimator and the inverse of the fast uniform sampled plant. We assume that the plant is open-loop stable and the disturbance consists of a sum of finite number of sinusoids with different frequencies. An example is presented for illustrations.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.521-521
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• 2000

This paper investigates the problem of robust H$_{\infty}$ filter with FIR(Finite Impulse Response) structure for linear continuous time-varying systems with sampled-data measurements. It is assumed that the system is subject to real time-varying uncertainty which is represented by the state-space model having parameter uncertainty. The robust H$_{\infty}$ FIR filter is proposed for the continuous-time linear parameter uncertain systems. It is also derived from the equivalence relationship between the robust linear H$_{\infty}$ FIR filter and the robust linear H$_{\infty}$ filter with sampled-data measurements.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.85-88
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• 2021

제조 설비에서 짧은 주기로 수집된 제조 데이터는 시간 간격이 일정하지 않은 불규칙 샘플링 시계열이고 값이 불안정하여 큰 분산을 가지는 경우가 많다. 본 논문에서는 단순이동평균법을 이용하여 불규칙 시계열의 시간 간격을 일정하게 보정함과 동시에 값의 분산을 줄이는 보정 기법을 제안하고, 제안된 보정 기법이 생산 설비의 이상탐지의 성능 향상에 효과가 있음을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1209-1212
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• 1996

In this paper, we design a stabilizing controller with disturbance rejection properties for multirate sampled-data systems which have periodic output measurement scheme. We assume that the plant is open-loop unstable and the disturbance consists of a sum of finite number of sine waves with different frequencies. A sufficient condition for maintaining observability in multirate sampled-data systems is derived. The proposed controller has an IMC structure and can be decomposed into the filtered-disturbance estimator and the inverse of the fast uniform sampled model of the pre-stabilized plant. An example is presented for illustrations.

• 전기의세계
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• 제26권2호
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• pp.84-88
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• 1977

In this paper we apply the maximum principle to design of time optimal nonlinear sampled-data control systems. We introduce the general design procedures and the mathematical formalas for time optimal processes and trajectories. Then we show the application of the technique to determine the optimal control signal, control sequence, switching time and sampling period to the given 4th order process.

• 전기학회논문지
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• 제56권7호
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• pp.1177-1182
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• 2007

Recently, IEC61850 supports the standardized communication technique in both station bus and process bus, and presents the substation automation model. In this paper, we propose the required techniques to develop the Merging Unit (MU), which is one of the important data acquisition equipment in substation automation, under IEC61850 communication protocol. Especially, we also propose the precision time synchronization technique using GPS(Global Positioning System) for the MU. IEC61850-9-2 SV (Sampled Value) service is applied to the MU which is designed using microprocessor. In order to evaluate the performance of the proposed MU, the playback program, which can reconstruct the transmitted sampled value data on the basis of time information, is developed and the performance of the IEC61850 SV service for MU is verified experimentally.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.708-710
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• 2004

This paper studies a multirate sampled-data control for LTI systems by using the digital redesign (DR) method. In this note, to well tackle the problem associated with both the state matching and the stabilization, our nobel strategy is to minimize the linear quadratic cost function. The main features of the proposed method are that i) the delta-operator-based descretization method is applied to improve the state-matching performance in the fast sampling limit and/or the large input multiplicity; ii) the proposed multirate control scheme can improve the state-matching performance in the long sampling limit; iii) some sufficient conditions that guarantee the stability of the closed-loop discrete-time system and provide a guarantee cost for the cost function can be formulated in the LMIs format; and iv) an optimal sampled-data controller in the sense of minimizing the upper bound of the cost function is also given by means of an LMI optimization procedure.