• Title/Summary/Keyword: Least Squares Algorithm

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Adaptive Filter for Noise Cancellation of ECG's (심전도 신호의 잡음 제거를 위한 적응 필터)

  • Lee, Jae-Joon;Song, Chul-Gyu;Lee, Je-Suk;Lee, Myoung-Ho
    • Proceedings of the KOSOMBE Conference
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    • v.1992 no.05
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    • pp.186-189
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    • 1992
  • Adaptive fliter for noise cancellation of ECG is proposed. An adaptive noise canceller using the least mean squares algorithm is used to reduce unwanted noise. The adaptive noise canceller minimizes the mean-square error between a primary input, which is the noisy ECG, and a reference input, which is either noise that is correlated in some way with the noise in the primary input or a signal that is correlated only with ECG in the primary input.

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On-line Static Load Modeling using Measurement Data (측정데이터를 이용한 실시간 정적 부하모델링)

  • Park, Sang-Hyun;Chung, Dong-Hyun;Kang, Sang-Gyun;Lee, Byong-Joon;Kwon, Sae-Hyuk
    • Proceedings of the KIEE Conference
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    • 2006.11a
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    • pp.282-284
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    • 2006
  • In this paper, Static load models are developed using measurement based approach which is fundamental for on-line load modeling. The measurement data can be acquired from PMU(phasor measurement units). On the assumption that we have on-line measurement data, a scheme which is for Static load model capable to apply SCADA/EMS is developed. The Least Squares criterion is used for minimizing between measured and simulated data. In this manner, On-line Static load modeling algorithm can be developed. In this paper, a scheme that simple Static load model is applied for On-line load modeling is studied.

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The development of semi-active suspension controller based on error self recurrent neural networks (오차 자기순환 신경회로망 기반 반능동 현가시스템 제어기 개발)

  • Lee, Chang-Goo;Song, Kwang-Hyun
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.8
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    • pp.932-940
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    • 1999
  • In this paper, a new neural networks and neural network based sliding mode controller are proposed. The new neural networks are an mor self-recurrent neural networks which use a recursive least squares method for the fast on-line leammg. The error self-recurrent neural networks converge considerably last than the back-prollagation algorithm and have advantage oi bemg less affected by the poor initial weights and learning rate. The controller for suspension system is designed according to sliding mode technique based on new proposed neural networks. In order to adapt shding mode control mnethod, each frame dstance hetween ground and vehcle body is estimated md controller is designed according to estimated neural model. The neural networks based sliding mode controller approves good peiformance throllgh computer sirnulations.

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Design of an Adaptive Robust Controller Based on Explorized Policy Iteration for the Stabilization of Multimachine Power Systems (다기 전력 시스템의 안정화를 위한 탐색화된 정책 반복법 기반 적응형 강인 제어기 설계)

  • Chun, Tae Yoon;Park, Jin Bae
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.11
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    • pp.1118-1124
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    • 2014
  • This paper proposes a novel controller design scheme for multimachine power systems based on the explorized policy iteration. Power systems have several uncertainties on system dynamics due to the various effects of interconnections between generators. To solve this problem, the proposed method solves the LQR (Linear Quadratic Regulation) problem of isolated subsystems without the knowledge of a system matrix and the interconnection parameters of multimachine power systems. By selecting the proper performance indices, it guarantees the stability and convergence of the LQ optimal control. To implement the proposed scheme, the least squares based online method is also investigated in terms of PE (Persistency of Excitation), interconnection parameters and exploration signals. Finally, the performance and effectiveness of the proposed algorithm are demonstrated by numerical simulations of three-machine power systems with governor controllers.

Multiple Model Prediction System Based on Optimal TS Fuzzy Model and Its Applications to Time Series Forecasting (최적 TS 퍼지 모델 기반 다중 모델 예측 시스템의 구현과 시계열 예측 응용)

  • Bang, Young-Keun;Lee, Chul-Heui
    • Journal of Industrial Technology
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    • v.28 no.B
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    • pp.101-109
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    • 2008
  • In general, non-stationary or chaos time series forecasting is very difficult since there exists a drift and/or nonlinearities in them. To overcome this situation, we suggest a new prediction method based on multiple model TS fuzzy predictors combined with preprocessing of time series data, where, instead of time series data, the differences of them are applied to predictors as input. In preprocessing procedure, the candidates of optimal difference interval are determined by using con-elation analysis and corresponding difference data are generated. And then, for each of them, TS fuzzy predictor is constructed by using k-means clustering algorithm and least squares method. Finally, the best predictor which minimizes the performance index is selected and it works on hereafter for prediction. Computer simulation is performed to show the effectiveness and usefulness of our method.

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Identification of DC-Link Capacitance for Single-Phase AC/DC PWM Converters

  • Pu, Xing-Si;Nguyen, Thanh Hai;Lee, Dong-Choon;Lee, Suk-Gyu
    • Journal of Power Electronics
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    • v.10 no.3
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    • pp.270-276
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    • 2010
  • In this paper, a capacitance estimation scheme for DC-link capacitors for single-phase AC/DC PWM converters is proposed. Under the no-load condition, a controlled AC current (30[Hz]) is injected into the input side, which then causes AC voltage ripples at the DC output side. Or, a controlled AC voltage can be directly injected into the DC output side. By extracting the AC voltage/current and power components on the DC output side using digital filters, the capacitance value can be calculated, where the recursive least squares (RLS) algorithm is used. The proposed methods can be simply implemented with software only and additional hardware is not required. From the experiment results, a high accuracy estimation of capacitances less than 0.85% has been obtained.

AN APPROACH TO WALSH FUNCTIONS FOR OPTIMAL CONTROL OF DETERMINISTIC SYSTEMS (확정계의 최적제어를 위한 WALSH함수 접근)

  • Ahn, Doo-Soo;Bae, Jong-Il;Lee, Myung-Kyu;Kim, Jong-Boo;Lee, Seung
    • Proceedings of the KIEE Conference
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    • 1989.07a
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    • pp.116-120
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    • 1989
  • The optimal control problem of linear Lumped Parameter Systems (LPS) and Distributed Parameter Systems (DPS) is studied by employing the technique of Walsh functions (WF). By the using the elegant operational properties of WF, a direct computational algorithm for evaluating the optimal control and trajectory of LPS and DPS is developed. Without the need of solving the traditional matrix Riccati equation, the WF approach in shown very simple in form and convenient for use of a computer. The approximation is in the sense of least squares employing WF as the basis and the results are in the piecewise constant and discrete form.

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Evolutionary Computation Approach to Wiener Model Identification

  • Oh, Kyu-Kwon;Okuyama, Yoshifumi
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.33.1-33
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    • 2001
  • We address a novel approach to identify a nonlinear dynamic system for Wiener models, which are composed of a linear dynamic system part followed by a nonlinear static part. The aim of system identification here is to provide the optimal mathematical model of both the linear dynamic and the nonlinear static parts in some appropriate sense. Assuming the nonlinear static part is invertible, we approximate the inverse function by a piecewise linear function. We estimate the piecewise linear inverse function by using the evolutionary computation approach such as genetic algorithm (GA) and evolution strategies (ES), while we estimate the linear dynamic system part by the least squares method. The results of numerical simulation studies indicate the usefulness of proposed approach to the Wiener model identification.

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Development and Evaluation of Stitching Algorithm With five Degrees of Freedom for Three-dimensional High-precision Texture of Large Surface (대면적/고정밀 3차원 표면형상의 5자유도 정합법 개발 및 평가)

  • Lee, Dong-Hyeok;Ahn, Jung-Hwa;Cho, Nham Gyoo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.23 no.2
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    • pp.118-126
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    • 2014
  • In this paper, a new method is proposed for the five-degree-of-freedom precision alignment and stitching of three-dimensional surface-profile data sets. The control parameters for correcting thealignment error are calculated from the surface profile data for overlapped areas among the adjacent measuring areas by using the "least squares method" and "maximum lag position of cross correlation function." To ensure the alignment and stitching reliability, the relationships betweenthe alignment uncertainty, overlapped area, and signal-to-noise level of the measured profile data are investigated. Based on the results of this uncertainty analysis, an appropriate size is proposed for the overlapped area according to the specimen's surface texture and noise level.

Large deflection analysis of point supported super-elliptical plates

  • Altekin, Murat
    • Structural Engineering and Mechanics
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    • v.51 no.2
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    • pp.333-347
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    • 2014
  • Nonlinear bending of super-elliptical plates of uniform thickness under uniform transverse pressure was investigated by the Ritz method. The material was assumed to be homogeneous and isotropic. The contribution of the boundary conditions at the point supports was introduced by the Lagrange multipliers. The solution was obtained by the Newton-Raphson method. The influence of the location of the point supports on the central deflection was highlighted by sensitivity analysis. An approximate relationship between the central deflection and the super-elliptical power was obtained using the method of least squares. The critical points where the maximum deflection may develop, and the influence of nonlinearity were highlighted. The nonlinearity was found to be sensitive to the aspect ratio. The accuracy of the algorithm was validated by comparing the central deflection with the solutions of elliptical and rectangular plates.