• 제목/요약/키워드: back propagation algorithm

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위치제어계에서 모먼텀 항을 갖는 신경망 알고리듬 의한 PID 제어기 설계 (A Design PID Controller by Neural Network algorithm with Momentum term in Position control system)

  • 박광현;허진영;하홍곤
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2001년도 추계종합학술대회
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    • pp.380-385
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    • 2001
  • 본 논문에서는 기존의 역전파 알고리즘(Back-propagation Algorithm)의 문제점인 지역 최소점(Local Minimum point) 빠질 위험을 제거함과 동시에 학습속도(learning-speed)를 빠르게 하기 위해서 모먼팀을 갖는 PID 역전파 알고리듬(PIDBPMT: PID Back-Propagation algorithm with Momentum Term)을 제안하여 모먼텀 항을 갖는 신경망 PID 제어기를 설계하였다. 그 제어기를 D.C 서보 모터를 구동원으로 하는 위치제어계에서 적용하여 시뮬레이션으로 그 성능을 검정하였다.

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A Simple Approach of Improving Back-Propagation Algorithm

  • Zhu, H.;Eguchi, K.;Tabata, T.;Sun, N.
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 ITC-CSCC -2
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    • pp.1041-1044
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    • 2000
  • The enhancement to the back-propagation algorithm presented in this paper has resulted from the need to extract sparsely connected networks from networks employing product terms. The enhancement works in conjunction with the back-propagation weight update process, so that the actions of weight zeroing and weight stimulation enhance each other. It is shown that the error measure, can also be interpreted as rate of weight change (as opposed to ${\Delta}W_{ij}$), and consequently used to determine when weights have reached a stable state. Weights judged to be stable are then compared to a zero weight threshold. Should they fall below this threshold, then the weight in question is zeroed. Simulation of such a system is shown to return improved learning rates and reduce network connection requirements, with respect to the optimal network solution, trained using the normal back-propagation algorithm for Multi-Layer Perceptron (MLP), Higher Order Neural Network (HONN) and Sigma-Pi networks.

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역전달 신경회로망을 이용한 심전도 파형의 부정맥 분류 (Classification of ECG Arrhythmia Signals Using Back-Propagation Network)

  • 권오철;최진영
    • 대한의용생체공학회:의공학회지
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    • 제10권3호
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    • pp.343-350
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    • 1989
  • A new algorithm classifying ECG Arrhythmia signals using Back-propagation network is proposed. The base-line of ECG signal is detected by high pass filter and probability density function then input data are normalized for learning and classifying. In addition, ECG data are scanned to classify Arrhythmia signal which is hard to find R-wave. A two-layer perceptron with one hidden layer along with error back-propagation learning rule is utilized as an artificial neural network. The proposed algorithm shows outstanding performance under circumstances of amplitude variation, baseline wander and noise contamination.

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Levenberg-Marquardt 알고리즘의 지반공학 적용성 평가 (Evaluation for Applications of the Levenberg-Marquardt Algorithm in Geotechnical Engineering)

  • 김영수;김대만
    • 한국지반환경공학회 논문집
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    • 제10권5호
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    • pp.49-57
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    • 2009
  • 본 연구에서는 Levenberg-Marquardt(LM) 알고리즘 인공신경망을 통하여 지반공학 문제 중의 하나인 압축지수를 예측하였고, 예측된 결과는 현재 지반공학에 널리 사용되고 있는 Back Propagation(BP) 알고리즘 인공신경망의 예측 결과와 비교하여 LM 알고리즘의 지반공학 적용성을 평가하였다. 또한 두 알고리즘에 의한 예측치는 기존에 제안된 압축지수의 경험식들에 의하여 산정된 결과들과 비교를 통하여 예측결과의 정확성을 확인하였다. 경험식에 의한 압축지수의 산정치는 전반적으로 BP 알고리즘과 LM 알고리즘 인공신경망에 의한 예측치에 비하여 더 큰 오차를 나타냈다. LM 알고리즘에 의한 압축지수의 예측치는 BP 알고리즘의 예측치와 비교할 때 정확도는 비슷하나 수렴속도에서 더 좋은 결과를 보여 LM 알고리즘의 지반공학 적용성은 우수한 것으로 나타났다.

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Identification of Partial Discharge Defects based on Back- Propagation Algorithm in Eco-friendly Insulation Gas

  • Sung-Wook Kim
    • Journal of information and communication convergence engineering
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    • 제21권3호
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    • pp.233-238
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    • 2023
  • This study presents a method for identifying partial discharge defects in an eco-friendly gas insulated system using a backpropagation algorithm. Four partial discharge (PD) electrode systems, namely, a free-moving particle, protrusion on the conductor, protrusion on the enclosure, and voids, were designed to simulate PD defects that can occur during the operation of eco-friendly gas-insulated switchgear. The PD signals were measured using an ultrahigh-frequency sensor as a nonconventional method based on IEC 62478. To identify the types of PD defects, the PD parameters of single PD pulses in the time and frequency domains and the phase-resolved partial discharge patterns were extracted, and a back-propagation algorithm in the artificial neural network was designed using a virtual instrument based on LabVIEW. The backpropagation algorithm proposed in this paper has an accuracy rate of over 90% for identifying the types of PD defects, and the result is expected to be used as a reference database for asset management and maintenance work for eco-friendly gas-insulated power equipment.

Back Propagation 알고리즘을 이용한 산업용 로봇의 견실 제어 (Robust Control of Industrial Robot Based on Back Propagation Algorithm)

  • 윤주식;이희섭;윤대식;한성현
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2004년도 춘계학술대회 논문집
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    • pp.253-257
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    • 2004
  • Neural networks are works are used in the framework of sensor based tracking control of robot manipulators. They learn by practice movements the relationship between PSD(an analog Position Sensitive Detector) sensor readings for target positions and the joint commands to reach them. Using this configuration, the system can track or follow a moving or stationary object in real time. Furthermore, an efficient neural network architecture has been developed for real time learning. This network uses multiple sets of simple back propagation networks one of which is selected according to which division(corresponding to a cluster of the self-organizing feature map) in data space the current input data belongs to. This lends itself to a very training and processing implementation required for real time control.

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Implementation of Speed Sensorless Induction Motor drives by Fast Learning Neural Network using RLS Approach

  • Kim, Yoon-Ho;Kook, Yoon-Sang
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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    • pp.293-297
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    • 1998
  • This paper presents a newly developed speed sensorless drive using RLS based on Neural Network Training Algorithm. The proposed algorithm has just the time-varying learning rate, while the wellknown back-propagation algorithm based on gradient descent has a constant learning rate. The number of iterations required by the new algorithm to converge is less than that of the back-propagation algorithm. The theoretical analysis and experimental results to verify the effectiveness of the proposed control strategy are described.

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적응 역전파 신경회로망의 은닉 층 노드 수 설정에 관한 연구 (On the set up to the Number of Hidden Node of Adaptive Back Propagation Neural Network)

  • 홍봉화
    • 정보학연구
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    • 제5권2호
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    • pp.55-67
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    • 2002
  • 본 논문에서는 학습계수를 발생한 오차에 따라서 적응적으로 갱신할 수 있는 학습알고리즘에 은닉 노드의 수를 다양하게 변화시킬 수 있는 적응 역 전파(Back Propagation) 알고리즘을 제안하였다. 제안한 알고리즘은 국소점을 벗어날 수 있는 것으로 기대되고, 수렴환경에 알맞은 은닉 노드의 수를 설정할 수 있다. 모의실험에서는 두 가지의 학습패턴을 가지고 실험하였다. 하나는 X-OR 문제에 대한 학습과 또 다른 하나는 $7{\times}5$ 도트 영문자 폰트에 에 대한 학습이다. 두 모의실험에서 국소 점으로 안주할 확률은 감소하였다. 또한, 영문자 폰트 학습에서의 신경회로망은 기존의 역 전파 알고리즘과 HNAD 알고리즘에 비하여 약 41.56%~58.28%정도 학습효율이 향상됨을 고찰하였다.

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역전파 알고리즘을 이용한 웨이퍼의 다이싱 상태 모니터링 (Monitoring of Wafer Dicing State by Using Back Propagation Algorithm)

  • 고경용;차영엽;최범식
    • 제어로봇시스템학회논문지
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    • 제6권6호
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    • pp.486-491
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    • 2000
  • The dicing process cuts a semiconductor wafer to lengthwise and crosswise direction by using a rotating circular diamond blade. But inferior goods are made under the influence of several parameters in dicing such as blade, wafer, cutting water and cutting conditions. This paper describes a monitoring algorithm using neural network in order to find out an instant of vibration signal change when bad dicing appears. The algorithm is composed of two steps: feature extraction and decision. In the feature extraction, five features processed from vibration signal which is acquired by accelerometer attached on blade head are proposed. In the decision, back-propagation neural network is adopted to classify the dicing process into normal and abnormal dicing, and normal and damaged blade. Experiments have been performed for GaAs semiconductor wafer in the case of normal/abnormal dicing and normal/damaged blade. Based upon observation of the experimental results, the proposed scheme shown has a good accuracy of classification performance by which the inferior goods decreased from 35.2% to 6.5%.

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Back-propargation 알고리즘을 이용한 컨테이너 식별자 인식에 관한 연구 (A study on the container identifier recognization using back-propagation algorithm)

  • 이만형;황대훈
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 하계종합학술대회논문집
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    • pp.944-947
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    • 1998
  • 오늘날 항만에서의 컨테이너 처리를 하지 못하고 있는 가운데 자동화 처리를 위해서는 식별자의 인식이 가장 큰 문제점을 해결하기 위해 항만에서 컨테이너의 식별자 인식에 신경망 알고리즘의 하나인 back-propagation을 사용하여 기존의 식별자 인식 방법보다 신속하고 정확한 처리가 가능하도록 구현하였다.

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