• Title/Summary/Keyword: Back-propagation neural networks

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Comparison of the BOD Forecasting Ability of the ARIMA model and the Artificial Neural Network Model (ARIMA 모형과 인공신경망모형의 BOD예측력 비교)

  • 정효준;이홍근
    • Journal of Environmental Health Sciences
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    • v.28 no.3
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    • pp.19-25
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    • 2002
  • In this paper, the water quality forecast was performed on the BOD of the Chungju Dam using the ARIMA model, which is a nonlinear statistics model, and the artificial neural network model. The monthly data of water quality were collected from 1991 to 2000. The most appropriate ARIMA model for Chungju dam was found to be the multiplicative seasonal ARIMA(1,0,1)(1,0,1)$_{12}$, model. While the artificial neural network model, which is used relatively often in recent days, forecasts new data by the strength of a learned matrix like human neurons. The BOD values were forecasted using the back-propagation algorithm of multi-layer perceptrons in this paper. Artificial neural network model was com- posed of two hidden layers and the node number of each hidden layer was designed fifteen. It was demonstrated that the ARIMA model was more appropriate in terms of changes around the overall average, but the artificial neural net-work model was more appropriate in terms of reflecting the minimum and the maximum values.s.

Design of Real-Time Newral-Network Controller Based-on DSPs of a Assembling Robot (DSP를 이용한 조립용 로봇의 실시간 신경회로망 제어기 설계)

  • 차보남
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.10a
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    • pp.113-118
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    • 1999
  • This paper presents a new approach to the design of neural control system using digital signal processors in order to improve the precision and robustness. Robotic manipulators have become increasingly important n the field of flexible automation. High speed and high-precision trajectory tracking are indispensable capabilities for their versatile application. The need to meet demanding control requirement in increasingly complex dynamical control systems under significant uncertainties, leads toward design of intelligent manipulation robots. The TMS320C31 is used in implementing real time neural control to provide an enhanced motion control for robotic manipulators. In this control scheme, the networks introduced are neural nets with dynamic neurons, whose dynamics are distributed over all the network nodes. The nets are trained by the distributed dynamic back propagation algorithm. The proposed neural network control scheme is simple in structure, fast in computation, and suitable for implementation of real-time control. Performance of the neural controller is illustrated by simulation and experimental results for a SCARA robot.

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Hydrological Forecasting Based on Hybrid Neural Networks in a Small Watershed (중소하천유역에서 Hybrid Neural Networks에 의한 수문학적 예측)

  • Kim, Seong-Won;Lee, Sun-Tak;Jo, Jeong-Sik
    • Journal of Korea Water Resources Association
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    • v.34 no.4
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    • pp.303-316
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    • 2001
  • In this study, Radial Basis Function(RBF) Neural Networks Model, a kind of Hybrid Neural Networks was applied to hydrological forecasting in a small watershed. RBF Neural Networks Model has four kinds of parameters in it and consists of unsupervised and supervised training patterns. And Gaussian Kernel Function(GKF) was used among many kinds of Radial Basis Functions(RBFs). K-Means clustering algorithm was applied to optimize centers and widths which ate the parameters of GKF. The parameters of RBF Neural Networks Model such as centers, widths weights and biases were determined by the training procedures of RBF Neural Networks Model. And, with these parameters the validation procedures of RBF Neural Networks Model were carried out. RBF Neural Networks Model was applied to Wi-Stream basin which is one of the IHP Representative basins in South Korea. 10 rainfall events were selected for training and validation of RBF Neural Networks Model. The results of RBF Neural Networks Model were compared with those of Elman Neural Networks(ENN) Model. ENN Model is composed of One Step Secant BackPropagation(OSSBP) and Resilient BackPropagation(RBP) algorithms. RBF Neural Networks shows better results than ENN Model. RBF Neural Networks Model spent less time for the training of model and can be easily used by the hydrologists with little background knowledge of RBF Neural Networks Model.

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The analysis of EEG under color stimulation and the quantization of emotion using learning neural network (색 자극에 대한 뇌전위 분석과 신경망 학습을 통한 인간 감성의 정량화에 관한 연구)

  • 김희선;이창구;김성중
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1628-1630
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    • 1997
  • The purpose of this study is to see the method of the analysis of EEG(Electroencephalography) whcih is a nonlinear system, to quantize human emotion under color stimulation using the analysis of EEG. The result of this study would be used clinical study and development fo image instruments with color. In this study, the method of the analysis of EEG is power spectrum using FFT(Fast Fourier Transform) and the modelling of EEG under color stimulation base on back propagation Neural Networks ond of AI(Artfical Intellignece) skills. First, input layer make a match to relative power which get analyzing s in 4 channels, and output layer make a match to color stimulation which is measured human emotion. Finally, weights of each neurons determine by learing back porpagation Neural Networks.

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A Study on the Forecasting of Daily Streamflow using the Multilayer Neural Networks Model (다층신경망모형에 의한 일 유출량의 예측에 관한 연구)

  • Kim, Seong-Won
    • Journal of Korea Water Resources Association
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    • v.33 no.5
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    • pp.537-550
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    • 2000
  • In this study, Neural Networks models were used to forecast daily streamflow at Jindong station of the Nakdong River basin. Neural Networks models consist of CASE 1(5-5-1) and CASE 2(5-5-5-1). The criteria which separates two models is the number of hidden layers. Each model has Fletcher-Reeves Conjugate Gradient BackPropagation(FR-CGBP) and Scaled Conjugate Gradient BackPropagation(SCGBP) algorithms, which are better than original BackPropagation(BP) in convergence of global error and training tolerance. The data which are available for model training and validation were composed of wet, average, dry, wet+average, wet+dry, average+dry and wet+average+dry year respectively. During model training, the optimal connection weights and biases were determined using each data set and the daily streamflow was calculated at the same time. Except for wet+dry year, the results of training were good conditions by statistical analysis of forecast errors. And, model validation was carried out using the connection weights and biases which were calculated from model training. The results of validation were satisfactory like those of training. Daily streamflow forecasting using Neural Networks models were compared with those forecasted by Multiple Regression Analysis Mode(MRAM). Neural Networks models were displayed slightly better results than MRAM in this study. Thus, Neural Networks models have much advantage to provide a more sysmatic approach, reduce model parameters, and shorten the time spent in the model development.

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A number detection and recognition through a neural network (신경망을 통한 숫자 검출 및 인식)

  • Cho, Hyun-Gu;Kim, Nam-Ho;Kim, Chan-Soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.10a
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    • pp.981-984
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    • 2007
  • Character recognition is one field of pattern recognition which comes true the ability of the human being with the computer. In this paper, we performed a comparative study on mostly used method of number detection and recognition. Also number recognition from hazard brain the human being with the model. We research about fundamental principle and back propagation algorithm for studying of neural networks.

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Multi-temporal Remote-Sensing Imag e ClassificationUsing Artificial Neural Networks (인공신경망 이론을 이용한 위성영상의 카테고리분류)

  • Kang, Moon-Seong;Park, Seung-Woo;Lim, Jae-Chon
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2001.10a
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    • pp.59-64
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    • 2001
  • The objectives of the thesis are to propose a pattern classification method for remote sensing data using artificial neural network. First, we apply the error back propagation algorithm to classify the remote sensing data. In this case, the classification performance depends on a training data set. Using the training data set and the error back propagation algorithm, a layered neural network is trained such that the training pattern are classified with a specified accuracy. After training the neural network, some pixels are deleted from the original training data set if they are incorrectly classified and a new training data set is built up. Once training is complete, a testing data set is classified by using the trained neural network. The classification results of Landsat TM data show that this approach produces excellent results which are more realistic and noiseless compared with a conventional Bayesian method.

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The Azimuth and Velocity Control of a Movile Robot with Two Drive Wheel by Neutral-Fuzzy Control Method (뉴럴-퍼지제어기법에 의한 두 구동휠을 갖는 이동 로봇의 자세 및 속도 제어)

  • 한성현
    • Journal of Ocean Engineering and Technology
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    • v.11 no.1
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    • pp.84-95
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    • 1997
  • This paper presents a new approach to the design speed and azimuth control of a mobile robot with drive wheel. The proposed control scheme uses a Gaussian function as a unit function in the fuzzy-neural network, and back propagation algorithm to train the fuzzy-neural network controller in the frmework of the specialized learning architecture. It is proposed a learning controller consisting of two neural network-fuzzy based on independent reasoning and a connection net with fixed weights to simple the neural networks-fuzzy. The performance of the proposed controller is shown by performing the computer simulation for trajectory tracking of the speed and azimuth of a mobile robot driven by two independent wheels.

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Performance Evaluation of Linear Regression, Back-Propagation Neural Network, and Linear Hebbian Neural Network for Fitting Linear Function (선형함수 fitting을 위한 선형회귀분석, 역전파신경망 및 성현 Hebbian 신경망의 성능 비교)

  • 이문규;허해숙
    • Journal of the Korean Operations Research and Management Science Society
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    • v.20 no.3
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    • pp.17-29
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    • 1995
  • Recently, neural network models have been employed as an alternative to regression analysis for point estimation or function fitting in various field. Thus far, however, no theoretical or empirical guides seem to exist for selecting the tool which the most suitable one for a specific function-fitting problem. In this paper, we evaluate performance of three major function-fitting techniques, regression analysis and two neural network models, back-propagation and linear-Hebbian-learning neural networks. The functions to be fitted are simple linear ones of a single independent variable. The factors considered are size of noise both in dependent and independent variables, portion of outliers, and size of the data. Based on comutational results performed in this study, some guidelines are suggested to choose the best technique that can be used for a specific problem concerned.

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Input Signal Estimation About Controller Using Neural Networks (신경망을 이용한 제어기에 인가된 입력 신호의 추정)

  • Son Jun-Hyeok;Seo Bo-Hyeok
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.8
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    • pp.495-497
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    • 2005
  • Recently Neural Network techniques have widely used in adaptive and learning control schemes for production systems. However, generally it costs a lot of time for learning in the case applied in control system. Furthermore, the physical meaning of neural networks constructed as a result is not obvious. And this method has been used as a learning algorithm to estimate the parameter of a neural network used for identification of the process dynamics of s signal input and signal output system and it was shown that this method offered superior capability over the conventional back propagation algorithm. This controller is designed by using three-layered neural networks. The effectiveness of the proposed Neural Network-based control scheme is investigated through an application for a production control system. This control method can enable a plant to operate smoothy and obviously as the plant condition varies with any unexpected accident. This paper goal estimate input signal about controller using neural networks.