• Title/Summary/Keyword: recursive

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FPGA Implementation of Recursive DFT based Phase Measurement Algorithm (DFT 연산 FPGA 모들에 기반한 위상 측정 앨고리즘의 구현)

  • Ahn Byoung-Sun;Kim Byoung-Il;Chang Tae-Gyu
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.3
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    • pp.191-193
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    • 2005
  • This paper proposes a phase measurement algorithm which is based on the recursive implementation of sliding-DFT. The proposed algorithm is designed to have a robust behavior against the erroneous factors of frequency drift, additive noise, and twiddle factor approximation. Four channel power-line phase measurement system is also designed and implemented based on the time-multiplexed sharing architecture of the proposed algorithm. The proposed algorithm's features of phase measurement accuracy and its robustness against the finite wordlength effects can provide a significant impact especially for the ASIC or microprocessor based embedded system applications where the enhanced processing speed and implementation simplicity are crucial design considerations.

A Study on Design of Neural Network for the Prediction of EEG with Chaotic Characteristics (카오스 특성을 갖는 뇌파신호의 예측을 위한 신경회로망 설계에 관한 연구)

  • Shin, Chang-Yong;Kim, Taek-Soo;Park, Sang-Hui
    • Proceedings of the KOSOMBE Conference
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    • v.1995 no.05
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    • pp.265-269
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    • 1995
  • In this study, we present a training method of radial basis function networks based on recursive modified Gram-Schmidt algorithm for single step prediction of chaotic time series. With single step predictions of Mackey-Glass time series and alpha-rhythm EEG which has chaotic characteristics, the radial basis function network trained by this method is compared with one trained by a classical non-recursive method and the radial basis function model proposed by X.D. He and A. Lapedes. The results show the effectiveness of the training method.

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Analysis of Electrohydraulic Left Ventricular Asistant Device using Recursive Parameter Estimation Algorithm (파라메타 추정 알고리듬을 이용한 전기유압식 좌심실 보조 장치의 해석)

  • Lee, Dong-Joon;Lee, Sang-Woo;Kim, Hee-Chan;Min, Byung-Goo
    • Proceedings of the KOSOMBE Conference
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    • v.1995 no.05
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    • pp.117-119
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    • 1995
  • 서울대학교 의공학과에서는 부분적인 심부전 판자의 보조 및 치료장비로 전기유압식 좌심실 보조 장치를 개발하고 있다. 이 장비의 경우 인체의 좌심방 및 대동맥에 직접 연결되므로 실제적으로 좌심실 보조 장치의 박출량을 센서를 통하여 알아내는 데에는 여러가지 어려움이 따른다. 이러한 필요성에 비추어 전기유압식 좌심실 보조 장치의 박출량을 시스템을 ARX모델로 모델링하여 RLS(Recursive Least Square) 알고리듬을 이용하여 추정하였다. 그 결과 비교적 높은 정착도로 박출량이 추정됨을 볼 수 있었다. 하지만, ARX모델의 특성상 원래 본 연구의 시작과정에서 분석한 시스템의 동적 특성을 완전하게 반영할 수 없었다. 앞으로 시스템의 파라미터 추정 과정에서 이미 주어진 동적 특성은 고정시키고 나머지 파라미터들만을 추정하는 알고리듬을 개발하는 것도 흥미로운 과제라 할 수 있다.

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Vehicle Mass and Road Grade Estimation for Longitudinal Acceleration Controller of an Automated Bus (자율주행 버스의 종방향 제어를 위한 질량 및 종 경사 추정기 개발)

  • Jo, Ara;Jeong, Yonghwan;Lim, Hyungho;Yi, Kyongsu
    • Journal of Auto-vehicle Safety Association
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    • v.12 no.2
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    • pp.14-20
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    • 2020
  • This paper presents a vehicle mass and road grade estimator for developing an automated bus. To consider the dynamic characteristics of a bus varying with the number of passengers, the longitudinal controller needs the estimation of the vehicle's mass and road grade in real-time and utilizes the information to adjust the control gains. Discrete Kalman filter is applied to estimate the time-varying road grade, and the recursive least squares algorithm is adopted to account for the constant mass estimation. After being implemented in MATLAB/Simulink, the estimators are evaluated with the dynamic model and experimental data of the target bus. The proposed estimators will be applied to complement the algorithm of the longitudinal controller and proceed with algorithm verification.

Diagnostics of Rotating Machinery using Recursive Bayesian Estimation (재귀 베이시안 추정을 이용한 회전기기 진단)

  • Oh, Joon-Seok;Sohn, Seok-Man;Kim, Hee-Soo;Lee, Seung-Cheol;Bae, Yong-Chae
    • KEPCO Journal on Electric Power and Energy
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    • v.6 no.1
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    • pp.49-52
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    • 2020
  • Since power plant is an important system to provide electricity, it is necessary to monitor it in order to operate safely. Much information related with machine diagnosis exists in written form instead of digital data. So, it causes difficulties of analyzing and finding solutions. Rulebased expert system can provide flexible and effective solutions to users. In this paper, Recursive Bayesian Estimation is applied in order to increase accuracy of solutions.

Nonlinear Neural Networks for Vehicle Modeling Control Algorithm based on 7-Depth Sensor Measurements (7자유도 센서차량모델 제어를 위한 비선형신경망)

  • Kim, Jong-Man;Kim, Won-Sop;Sin, Dong-Yong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.525-526
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    • 2008
  • For measuring nonlinear Vehicle Modeling based on 7-Depth Sensor, the neural networks are proposed m adaptive and in realtime. The structure of it is similar to recurrent neural networks; a delayed output as the input and a delayed error between the output of plant and neural networks as a bias input. In addition, we compute the desired value of hidden layer by an optimal method instead of transfering desired values by backpropagation and each weights are updated by RLS(Recursive Least Square). Consequently, this neural networks are not sensitive to initial weights and a learning rate, and have a faster convergence rate than conventional neural networks. This new neural networks is Error Estimated Neural Networks. We can estimate nonlinear models in realtime by the proposed networks and control nonlinear models.

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Curve Fitting with Recursive Ball Curve (Ball 곡선을 이용한 Fitting 알고리즘)

  • Lee, A-Ri;Choe, Yeong-Geun
    • The KIPS Transactions:PartA
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    • v.8A no.1
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    • pp.42-47
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    • 2001
  • In this paper, we present a curve fitting algorithm using a ball curve. Our algorithm is recursive method for fitting, which is not a traditional ball function but a continuous ball function. This algorithm consists of two steps. The first step, it is classified the composite corner points to joint points until selected from the given data set. The second step is the curve fitting. The basis function for curve fitting is use to ball function. Also, the weighted least square method, to insert knot, is an efficient method for piecewise ball curve and ball curve segments will be smoothly connected at all composit points. The proposed algorithm will be applied to represent image representation, like fonts, digital image and GIS.

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On the Complex-Valued Recursive Least Squares Escalator Algorithm with Reduced Computational Complexity

  • Kim, Nam-Yong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.5C
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    • pp.521-526
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    • 2009
  • In this paper, a complex-valued recursive least squares escalator filter algorithm with reduced computational complexity for complex-valued signal processing applications is presented. The local tap weight of RLS-ESC algorithm is updated by incrementing its old value by an amount equal to the local estimation error times the local gain scalar, and for the gain scalar, the local input autocorrelation is calculated at the previous time. By deriving a new gain scalar that can be calculated by using the current local input autocorrelation, reduced computational complexity is accomplished. Compared with the computational complexity of the complex-valued version of RLS-ESC algorithm, the computational complexity of the proposed method can be reduced by 50% without performance degradation. The reduced computational complexity of the proposed algorithm is even less than that of the LMS-ESC. Simulation results for complex channel equalization in 64QAM modulation schemes demonstrate that the proposed algorithm has superior convergence and constellation performance.

Autonomous Adaptive Digital Over Current Relay (계통변화를 고려한 자율 적응형 과전류 계전기)

  • 윤준석;최면송;이승재;현승호
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.52 no.8
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    • pp.444-449
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    • 2003
  • In this paper present Autonomous Adaptive Digital Over Current Relay for distribution networks which acts autonomous setting using the short circuit impedance measured by relay of power systems. Automation of relay setting is one of the basic requirements for distribution automation, although manual relay setting is used at present. The short circuit impedance from a power source in distribution networks essential for the Autonomous Relay Setting changes frequently in distribution networks. In this paper the short circuit impedance is calculated with voltage and current measured in real time operation of digital relay using the Recursive Least Squares. A new method of digital relay setting is introduced using the the short circuit impedance and load current.

Convergence analysis of stochastic recursive algorithms (DI기법에 의한 스토케스틱 순환적 알고리즘의 수렴분석)

  • Choo, Youn-Seok
    • Proceedings of the KIEE Conference
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    • 1995.07b
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    • pp.901-903
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    • 1995
  • The ordinary differential equation (ODE) method has been widely used for the convergence analysis of stochastic recursive algorithms. The principal objective of this method is to associate to a given algorithm a differential equation with continuous righthand side. Usually some assumptions should be imposed to get such a differential equation. If any of assumptions fails, then the ODE method cannot be used. Recently a new method using differential inclusions (DIs) was introduced in [3], which is useful to deal with those cases. The DI method shares the same idea with the ODE method, but it is different in that a differential inclusion is identified instead of a differential equation with continuous righthand side. In this paper, we briefly review the DI method and then analyze a Robbins and Monro (RM)-type algorithm. Our focus is placed on the projected algorithm.

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