• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.3
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• pp.14-21
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• 2007

Sight Stabilization system is the control system to preserve Line of Sight for the targets though many nonlinear disturbances and vibrations are generated. In this paper, we identified Stabilization system using RLS algorithm, one of the system identification algorithm and found out the modeling of system. Considering nonlinear operational condition this paper proposes two Knowledge-base controllers - Fuzzy controller, Fuzzy PI Gain Scheduling controller, and simulates the performances of proposed controllers compare with Lead PI controller being used in Sight system of NFIV.

• Journal of Auto-vehicle Safety Association
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• v.14 no.2
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• pp.26-38
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• 2022

This paper proposes multiple RLS and actuator performance index-based adaptive actuator fault-tolerant control and detection algorithms for longitudinal autonomous driving. The proposed algorithm computes the desired acceleration using feedback law for longitudinal autonomous driving. When actuator fault or performance degradation exists, it is designed that the desired acceleration is adjusted with the calculated feedback gains based on multiple RLS and gradient descent method for fault-tolerant control. In order to define the performance index, the error between the desired and actual accelerations is used. The window-based weighted error standard deviation is computed with the design parameters. Fault level decision algorithm that can represent three fault levels such as normal, warning, emergency levels is proposed in this study. Performance evaluation under various driving scenarios with actuator fault was conducted based on co-simulation of Matlab/Simulink and commercial software (CarMaker).

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.78-80
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• 1998

본 논문은 일차원의 시계열 데이터를 입력을 하여 위상공간 재구성 과정을 거쳐 다차원 위상공간상에서 프랙탈 차원을 계산하는 효율적인 방법을 제안한다. 프랙탈 차원의 추정에 소요되는 계산량을 줄이기 위해 로그 연산을 비트 연산으로 대체하고, 거리계산의 순서를 바꿈으로써 위상공간의 차원에 무관한 상수 시간의 계산복잡도를 가지는 알고리즘을 구현하였다. 또한 최소절단자승 추정기법을 적용하여 로그-로그 그래프 상에서의 기울기 추정을 함으로써 프랙탈 차원의 추정치에 대한 정확도를 높였다. 참값이 알려진 시계열 데이터에 대한 차원 추정 실험을 통하여 제안된 방법의 정확성을 보였다.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.285-289
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• 1988

This paper suggests the way to improve the impulse response characteristics in 1-D and 2-D FIR digital filters design. The proposed a Least Square($L_2$) error algorithm of kaiser window is the better than $L_2$ error of the Remez Exchange(R.E.)algorithm.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.305-308
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• 1988

Pole assignment controller with variable forgetting factor is generalizaed to allow the output and/or input variance to be reduced. The algorithm can give significant reductions in variance for little extra computational effort and is presented for servo-tracking using leat-squares estimation. Moreover, the use of a variable forgetting factor with correct choice of information bound can avoid 'blowing-up' of the covariance matrix of the estimates and subsequent unstable control.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.28A no.9
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• pp.671-679
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• 1991

In adaptive antenna, several models are known according to a prior knowledge about jammer signal. Among those, Frost model with contraint is generally used however it has the problem that convergence speed is slow and that stability is not good. To improve such problems, this paper proposes constrained NLMS algorithm using LS method. In addition, the result obtained by applying this algorithm to Duvall antenna model is compared with that of Frost model.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.208-210
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• 1998

A high speed digital distance relaying algorithm based on a modified least square error method is proposed. To obtain stable phasor values very Quickly, first, a lowpass filter which has very short transient period and no overshoot is used. Secondly, the conventional least square error method is modified to the one having the data window of 3 samples by applying a FIR filter which removes the DC-offset component in current relaying signals.

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.196-198
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• 2007

전력계통에서 상태추정은 신뢰도 높은 제어를 위해 매우 중요한 역할을 한다. 최근에는 상태추정 문제를 위해 가중최소자승법과 fast decoupled 방법이 많이 쓰이고 있다. 그러나 이런 알고리즘들은 지역해로 수렴하기 쉬운 단점이 있다. 이런 문제점을 극복하기 위해 PSO와 같은 heuristic한 방법을 이용한다. 본 논문에서는 전력계통에서 상태추정의 최적해를 구하기 위한 방법으로 PSO 알고리즘을 제안한다. 제안한 PSO알고리즘의 유용함을 증명하기 위해 IEEE-118모선 시스템에 적용해 보고, 그 결과로부터 전력계통의 상태 추정에 PSO 알고리즘의 적용가능성을 증명하였다.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.3
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• pp.87-95
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• 1998

This paper presents the method for the automatic tuning of a design weighting polynomial parameter of a generalized minimum-variance stochastic self tuning controller which adapts to changes in the system parameters with time delays and noises. The self tuning effect is achieved through the recursive least square algorithm at the parameter estimation stage and also through the Robbins-Monro algorithm at the stage of optimizing a design weighting polynomial parameters. The proposed self tuning method is simple and effective compared with other existing self tuning methods. The computer simulation results are presented to illustrate the procedure and to show the performance of the control system.

• Sleep Medicine and Psychophysiology
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• v.6 no.1
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• pp.52-60
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• 1999

Objectives: With the object of finding the appropriate conditions and algorithms for dimensional analysis of human EEG, we calculated correlation dimensions in the various condition of sampling rate and data aquisition time and improved the computation algorithm by taking advantage of bit operation instead of log operation. Methods: EEG signals from 13 scalp lead of a man were digitized with A-D converter under the condition of 12 bit resolution and 1000 Hertz of sampling rate during 32 seconds. From the original data, we made 15 time series data which have different sampling rate of 62.5, 125, 250, 500, 1000 hertz and data acqusition time of 10, 20, 30 second, respectively. New algorithm to shorten the calculation time using bit operation and the Least Trimmed Squares(LTS) estimator to get the optimal slope was applied to these data. Results: The values of the correlation dimension showed the increasing pattern as the data acquisition time becomes longer. The data with sampling rate of 62.5 Hz showed the highest value of correlation dimension regardless of sampling time but the correlation dimension at other sampling rates revealed similar values. The computation with bit operation instead of log operation had a statistically significant effect of shortening of calculation time and LTS method estimated more stably the slope of correlation dimension than the Least Squares estimator. Conclusion: The bit operation and LTS methods were successfully utilized to time-saving and efficient calculation of correlation dimension. In addition, time series of 20-sec length with sampling rate of 125 Hz was adequate to estimate the dimensional complexity of human EEG.