• Title/Summary/Keyword: neural network.

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Influence of Rainfall observation Network on Daily Dam Inflow using Artificial Neural Networks (강우자료 형태에 따른 인공신경망의 일유입량 예측 정확도 평가)

  • Kim, Seokhyeon;Kim, Kyeung;Hwang, Soonho;Park, Jihoon;Lee, Jaenam;Kang, Moonseong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.61 no.2
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    • pp.63-74
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    • 2019
  • The objective of this study was to evaluate the influence of rainfall observation network on daily dam inflow using artificial neural networks(ANNs). Chungju Dam and Soyangriver Dam were selected for the study watershed. Rainfall and dam inflow data were collected as input data for construction of ANNs models. Five ANNs models, represented by Model 1 (In watershed, point rainfall), Model 2 (All in the Thiessen network, point rainfall), Model 3 (Out of watershed in the Thiessen network, point rainfall), Model 1-T (In watershed, area mean rainfall), Model 2-T (All in the Thiessen network, area mean rainfall), were adopted to evaluate the influence of rainfall observation network. As a result of the study, the models that used all station in the Thiessen network performed better than the models that used station only in the watershed or out of the watershed. The models that used point rainfall data performed better than the models that used area mean rainfall. Model 2 achieved the highest level of performance. The model performance for the ANNs model 2 in Chungju dam resulted in the $R^2$ value of 0.94, NSE of 0.94 $NSE_{ln}$ of 0.88 and PBIAS of -0.04 respectively. The model-2 predictions of Soyangriver Dam with the $R^2$ and NSE values greater than 0.94 were reasonably well agreed with the observations. The results of this study are expected to be used as a reference for rainfall data utilization in forecasting dam inflow using artificial neural networks.

Force tracking impedance control of robot by learning of robot-environment dynamics (로봇-작업환경 동역학의 학습에 의한 로봇의 힘 추종 임피이던스 제어)

  • 신상운;최규종;김영원;안두성
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.548-551
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    • 1997
  • Performance of force tracking impedance control of robot manipulators is degraded by the uncertainties in the robot and environment dynamic model. The purpose of this paper is to improve the controller robustness by applying neural network. Neural networks are designed to learn the uncertainties in robot and environment model for compensating the uncertainties. The proposed scheme is verified through the simulation of 20DOF robot manipulator.

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Adaptive controls for non-linear plant using neural network (신경회로망을 이용한 비선형 플랜트의 적응제어)

  • 정대원
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.215-218
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    • 1997
  • A dynamic back-propagation neural network is addressed for adaptive neural control system to approximate non-linear control system rather than static networks. It has the capability to represent the approximation of nonlinear system without mathematical analysis and to carry out the on-line learning algorithm for real time application. The simulated results show fast tracking capability and adaptive response by using dynamic back-propagation neurons.

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A Neural Network Based Handwritten-Charater Recognition using Binary Wavelet Transform (이진 웨이브렛 변환을 이용한 신경회로망의 필기체 문자 인식)

  • Lee, Jung-Moon;You, Kyoung-San
    • Journal of Industrial Technology
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    • v.17
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    • pp.331-338
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    • 1997
  • In this paper, we propose a new neural pattern recognition from wavelet transform. We first analysis in BFT(Binary Field Transform) in character image. The proposed neural network and wavelet transform is able to improve learning time and scaling. The ability and effectiveness of identifying image using the proposed wavelet transform will be demonstrated by computer simulation.

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Nondestructive Spot Weld Quality Monitoring by an Artificial Neural Networks in Comparison with Regression Method (저항 점용접에서 비파괴 용접질 검사를 위한 인공신경회로망의 응용기법과 회귀법과의 비교)

  • 최용범;김상필;홍태민;이준희;장희석
    • Proceedings of the KWS Conference
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    • 1993.05a
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    • pp.115-119
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    • 1993
  • Many qualitive analyses of sampled process variables have been attempted to predict nugget size in resistance spot welding process. In this paper, dynamic resistance and electrode movement signal which is a good indicative of the nugget size was examined by introducing an artificial neural network estimator. An artificial neural feedforward network with back-propagation of error was applied for the estimation of the nugget size. To assess the advantage of this method. results have been compared with conventional regression method.

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Linear/nonlinear system identification and adaptive tracking control using neural networks (신경회로망을 이용한 선형/비선형 시스템의 식별과 적응 트래킹 제어)

  • 조규상;임제택
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.5
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    • pp.1-9
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    • 1996
  • In this paper, a parameter identification method for a discrete-time linear system using multi-layer neural network is proposed. The parameters are identified with the combination of weights and the output of neuraons of a neural network, which can be used for a linear and a nonlinear controller. An adaptive output tracking architecture is designed for the linear controller. And, the nonlinear controller. A sliding mode control law is applied to the stabilizing the nonlinear controller such that output errors can be reduced. The effectiveness of the proposed control scheme is illustrated through simulations.

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Sliding Manifold Tuning Method Using Wavelet Neural Network (웨이브릿 신경회로망을 활용한 슬라이딩 매니폴드 조정기법)

  • 홍석우;전홍태
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2000.11a
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    • pp.195-198
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    • 2000
  • Sliding mode control method is popularly used for robustness to distrurbance and variance of systems internal parameter. However, one of the serious problem of this method is Chattering which occurs in neighborhood of sliding manifold. Another problem is that we cannot expect robustness before system starts sliding mode. A new tuning method of sliding manifold which changes the parameter of sliding manifold dynamically using Wavelet Neural Network is proposed in this paper. We can expect the better performance in sliding mode control by the wavelet neural networks excellent property of approximating arbitrary function for multi-resolution analysis and decrease chattering drastically.

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Neural Networks and Logistic Models for Classification: A Case Study

  • Hwang, Chang-Ha
    • Journal of the Korean Data and Information Science Society
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    • v.7 no.1
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    • pp.13-19
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    • 1996
  • In this paper, we study and compare two types of methods for classification when both continuous and categorical variables are used to describe each individual. One is neural network(NN) method using backpropagation learning(BPL). The other is logistic model(LM) method. Both the NN and LM are based on projections of the data in directions determined from interconnection weights.

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Particle Sizing Using Light Scattering and Neural Networks (산란이론과 신경회로에 의한 입자크기계측)

  • 남부희;이상재;박민현;이영진;이석원;류태우;방병렬
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.6
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    • pp.447-453
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    • 2000
  • Using the scattering theory of laser light, we analyze the particle sizing method. The scattered profile measured by the photodetector is sampled, scale conditioned by a 32 channel analog-to-digital converter, and is analyzed with the transform matrix from the light energy signals to the weights of the particle sizes. The particle size distribution is classified using the Hopfield neural network method as well as the conventional nonnegative least square method.

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신경망을 이용한 차동조향 이동로봇의 추적제어

  • 계중읍;김무진;이영진;이만형
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.3
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    • pp.90-101
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    • 2000
  • In this paper, we propose a controller for differentially steered wheeled mobile robots. The controller uses input-output linearization algorithm and artificial neural network to stabilize the dynamic model and compensate uncertainties. The proposed neural network part has 6 inputs, 1 hidden layer, 2 torque outputs and features fast online learning and good performance on structure error learning basis. Simulation results show that the proposed controller perform precisely tracking of reference path and is robust to uncertainties.

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