• 제목/요약/키워드: Backpropagation Neural Network

검색결과 449건 처리시간 0.026초

Computation of Noncentral F Probabilities using Neural Network Theory (신경망이론을 이용한 비중심 F분포 확률계산)

  • 구선희
    • Journal of the Korea Society of Computer and Information
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    • 제1권1호
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    • pp.83-94
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    • 1996
  • The test statistic in ANOVA tests has a single or doubly noncentral F distribution and the noncentral F distribution is applied to the calculation of the power functions of tests of general linear hypotheses. In this paper. the evaluation of the cumulative function of the single noncentral F distribution is applied to the neural network theory. The neural network consists of the multi-layer perceptron structure and learning process has the algorithm of the backpropagation. Numerical comparisons are made between the results obtained by neural network theory and the Patnaik's values.

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An Auto-tuning of PID Controller using Fuzzy Performance Measure and Neural Network for Equipment System (전력설비시스템을 위한 퍼지 평가함수와 신경회로망을 사용한 PID제어기의 자동동조)

  • ;李壽欽
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • 제13권2호
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    • pp.195-195
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    • 1999
  • This paper is Proposed a new method to deal with the optimized auto-tuning for the PID controller which is used to the process-control in various fields. First of all, in this method, 1st order delay system with dead time which is modelled from the unit step response of the system is Pade-approximated, then initial values are determined by the Ziegler-Nickels method. So we can find the parameters of PID controller so as to minimize the fuzzy criterion function which includes the maximum overshoot, damping ratio, rising time and settling time. Finally, after studying the parameters of PID controller by Backpropagation of Neural-Network, when we give new K, L, T values to Neural-Network, the optimized parameter of PID controller is found by Neural-Network Program.

A Control Method of DC Servo Motor Using a Multi-Layered Neural Network (다층 신경회로망을 이용한 DC Servo Motor 제어방법)

  • Kim, S.W.;Kim, J.S.;Ryou, J.S.;Lee, Y.J.
    • Proceedings of the KIEE Conference
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    • 대한전기학회 1995년도 하계학술대회 논문집 B
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    • pp.855-858
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    • 1995
  • A neural network has very simple construction (input, output and connection weight) and then it can be robusted against some disturbance. In this paper, we proposed a neuro-controller using a Multi-Layered neural network which is combined with PD controller. The proposed neuro-controller is learned by backpropagation learning rule with momentum and neuro-controller adjusts connection weight in neural network to make approximate dynamic model of DC Servo motor. Computer Simulation results show that the proposed neuro-controller's performance is better than that of origianl PD controller.

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A Study on the Stabilization Control of an Inverted Pendulum Using Learning Control (학습제어를 이용한 도립진자의 안정화제어에 관한 연구)

  • 황용연
    • Journal of Advanced Marine Engineering and Technology
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    • 제23권2호
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    • pp.168-175
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    • 1999
  • Unlike a general inverted pendulum system which is moved on the cart the proposed inverted pendulum system in this paper has an inverted pendulum which is moved on the two-degree-of-freedom parallelogram link. The dynamic equation of the pendulum system activated by the DD(Direct Drive)motor includes many nonlinear terms and has the high degree of freedoms. The problem is followed hat the exact mathmatical equations can not be analized by a general linear theory However the neural network trained by a simple learning method can control the dynamic system with hard nonlinearities. Learning procedure is the backpropagation algorithm with super-visory signal. The plant inputs obtained by the designed neural network in this paper can stabilize the pendu-lem and get the servo control. Experiment results have proce the effectiveness of the designed neural network controller.

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Modeling of RF Sputtering Process for ZnO Thin film Deposition using Neural Network (신경회로망을 이용한 RF 스퍼터링 ZnO 박막 증착 프로세스 모델링)

  • Lim, Keun-Young;Lee, Sang-Keuk;Park, Choon-Bae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • 제19권7호
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    • pp.624-630
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    • 2006
  • ZnO deposition parameters are not independent and have a nonlinear and complex property. To propose a method that could verify and predict the relations of process variables, neural network was used. At first, ZnO thin films were deposited by using RF magnetron sputtering process with various conditions. Si, GaAs, and Glass were used as substrates. The temperature, work pressure, and RF power of the substrate were $50\sim500^{\circ}C$, 15 mTorr, and $180\sim210W$, respectively : the purity of the target was ZnO 4 N. Structural properties of ZnO thin films were estimated by using XRD (0002) peak intensity. The structure of neural network was a form of 4-7-1 that have one hidden layer. In training a network, learning rate and momentum were selected as 0.2, 0.6 respectively. A backpropagation neural network were performed with XRD (0002) peak data. After training a network, the temperature of substrate was evaluated as the most important parameter by sensitivity analysis and response surface. As a result, neural network could capture nonlinear and complex relationships between process parameters and predict structural properties of ZnO thin films with a limited set of experiments.

A Study on the Bayesian Recurrent Neural Network for Time Series Prediction (시계열 자료의 예측을 위한 베이지안 순환 신경망에 관한 연구)

  • Hong Chan-Young;Park Jung-Hoon;Yoon Tae-Sung;Park Jin-Bae
    • Journal of Institute of Control, Robotics and Systems
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    • 제10권12호
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    • pp.1295-1304
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    • 2004
  • In this paper, the Bayesian recurrent neural network is proposed to predict time series data. A neural network predictor requests proper learning strategy to adjust the network weights, and one needs to prepare for non-linear and non-stationary evolution of network weights. The Bayesian neural network in this paper estimates not the single set of weights but the probability distributions of weights. In other words, the weights vector is set as a state vector of state space method, and its probability distributions are estimated in accordance with the particle filtering process. This approach makes it possible to obtain more exact estimation of the weights. In the aspect of network architecture, it is known that the recurrent feedback structure is superior to the feedforward structure for the problem of time series prediction. Therefore, the recurrent neural network with Bayesian inference, what we call Bayesian recurrent neural network (BRNN), is expected to show higher performance than the normal neural network. To verify the proposed method, the time series data are numerically generated and various kinds of neural network predictor are applied on it in order to be compared. As a result, feedback structure and Bayesian learning are better than feedforward structure and backpropagation learning, respectively. Consequently, it is verified that the Bayesian reccurent neural network shows better a prediction result than the common Bayesian neural network.

An inverse dynamic torque control of a six-jointed robot arm using neural networks (신경회로를 이용한 6축 로보트의 역동력학적 토크 제어)

  • 조문증;오세영
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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    • pp.1-6
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    • 1990
  • Neural network is a computational model of ft biological nervous system developed ID exploit its intelligence and parallelism. Applying neural networks so robots creates many advantages over conventional control methods such as learning, real-time control, and continuous performance improvement through training and adaptation. In this paper, dynamic control of a six-link robot will be presented using neural networks. The neural network model used in this paper is the backpropagation network. Simulated control of the PUMA 560 am shows that it can move a high speed as well as adapt to unforseen load changes and sensor noise. The results are compared with the conventional PD control scheme.

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Dynamic Control of A Sik-link Robot Using Neural Networks (신경회로를 이용한 6축 Robot의 Dynamic Control)

  • Joe, Moon-Jeung;Oh, Se-Young
    • Proceedings of the KIEE Conference
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    • 대한전기학회 1990년도 하계학술대회 논문집
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    • pp.500-503
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    • 1990
  • Neural network is a computational model of the biological nervous system developed to exploit its intelligence and parallelism. Applying neural networks to robots creates many advantages over conventional control methods such as learning, real-time control, and continuous performance improvement through training and adaptation. In this paper, dynamic control of a six-link robot will be presented using neural networks. The neural network model used in this paper is the backpropagation network. Simulated control of the PUMA 560 arm shows that it can move at high speed as well as adapt to unforseen load changes. The results are compared with the conventional PD control scheme.

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A Design of the Fuzzy Neural Network Image Recognizer

  • Kim, Dae-Su
    • Journal of the Korean Institute of Intelligent Systems
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    • 제2권3호
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    • pp.50-57
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    • 1992
  • Neural networks have become more popular recently and are now being applied to numerous fiedls. One of the major applications of neural networks is image recognition. Various image recognition system have been proposed so far, but there is no definite solution yet. In this paper, we propose a design of Fuzzy Neural Network Image Recognizer(FNNIR). Our model uses a fuzzy neural network model, named SONN[KIM90]. This model returns the information of the number of clusters and cluster and cluster center values for a given image data ste. Unlike the well-kinwn backpropagation technique, we do not need retraining for new data. Our newly designed image recongitionsystem FNNIR that uses fuzzy merger is proposed and experimented for a sample color image.

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A study on EMG pattern recognition based on parallel radial basis function network (병렬 Radial Basis Function 회로망을 이용한 근전도 신호의 패턴 인식에 관한 연구)

  • Kim, Se-Hoon;Lee, Seung-Chul;Kim, Ji-Un;Park, Sang-Hui
    • Proceedings of the KIEE Conference
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    • 대한전기학회 1998년도 하계학술대회 논문집 G
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    • pp.2448-2450
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    • 1998
  • For the exact classification of the arm motion this paper proposes EMG pattern recognition method with neural network. For this autoregressive coefficient, linear cepstrum coefficient, and adaptive cepstrum coefficient are selected for the feature parameter of EMG signal, and they are extracted from time series EMG signal. For the function recognition of the feature parameter a radial basis function network, a field of neural network is designed. For the improvement of recognition rate, a number of radial basis function network are combined in parallel, comparing with a backpropagation neural network an existing method.

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