• Title/Summary/Keyword: neural network.

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Transient Stability Control of Power System using Passivity and Neural Network (시스템의 수동성과 신경망을 이용한 전력 시스템의 과도 안정도 제어)

  • Lee, Jung-Won;Lee, Yong-Ik;Shim, Duk-Sun
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.8
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    • pp.1004-1013
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    • 1999
  • This paper considers the transient stability problem of power system. The power system model is given as interconnected system consisting of many machines which are described by swing equations. We design a transient stability controller using passivity and neural network. The structure of the neural network controller is derived using a filtered error/passivity approach. In general, a neural network cannot be guaranteed to be passive, but the weight tuning algorithm given here do guarantee desirable passivity properties of the neural network and hence of the closed-loop error system. Moreover proposed controller shows good robustness by simulation for uncertainties in parameters, which can not be shown in the speed gradient method proposed by Fradkov[3,7].

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Feature Extraction of Letter Using Pattern Classifier Neural Network (패턴분류 신경회로망을 이용한 문자의 특징 추출)

  • Ryoo Young-Jae
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.2
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    • pp.102-106
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    • 2003
  • This paper describes a new pattern classifier neural network to extract the feature from a letter. The proposed pattern classifier is based on relative distance, which is measure between an input datum and the center of cluster group. So, the proposed classifier neural network is called relative neural network(RNN). According to definitions of the distance and the learning rule, the structure of RNN is designed and the pseudo code of the algorithm is described. In feature extraction of letter, RNN, in spite of deletion of learning rate, resulted in the identical performance with those of winner-take-all(WTA), and self-organizing-map(SOM) neural network. Thus, it is shown that RNN is suitable to extract the feature of a letter.

Control of an Inverted Pendulum Using Neural Network Predictor (신경망 예측기를 이용한 인버티드 펜듈럼의 제어)

  • Moon, Hyeong-Sug;Lee, Kyu-Yul;Kang, Young-Ho;Kim, Lark-Kyo
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.1031-1033
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    • 1996
  • Now is an automation age. Therefore it is required that machine can do work which was done by men. Artificial Neural Network was developed by the necessity of this purpose. This paper shows a Predictive Control with a Neural Network. The Neural Network learns an Inverted Pendulum in various situations. Then, it has a power to predict the next state after accept the current state. And the Neural Network directs the Bang-Bang Controller to give input to a plant. It seems like that a human expert looks the state of a plant and then controls the plant. It is used a Feedforward Neural Network and shown control state according to the learning. We could get a satisfactory results after complete learning.

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A Study on Rainfall Prediction by Neural Network (神經網理論에 의한 降雨豫測에 관한 硏究)

  • 오남선;선우중호
    • Water for future
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    • v.29 no.4
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    • pp.109-118
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    • 1996
  • The neural network is a mathematical model of theorized brain activity which attempts to exploit the parallel local processing and distributed storage properties. The neural metwork is a good model to be applied for the classification problem, large combinatorial optimization and nonlinear mapping. A multi-layer neural network is constructed to predict rainfall. The network learns continuourvalued input and output data. Application of neural network to 1-hour real data in Seoul metropolitan area and the Soyang River basin shows slightly good predictions. Therefore, when good data is available, the neural network is expected to predict the complicated rainfall successfully.

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Interval type-2 fuzzy radial basis function neural network (Interval 제 2 종 퍼지 radial basis function neural network)

  • Choe, Byeong-In;Lee, Jeong-Hun
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2006.11a
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    • pp.19-22
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    • 2006
  • Type-2 fuzzy 이론은 기존의 퍼지 이론보다 패턴의 불확실성에 대한 제어를 더 향상시킬 수 있다. 반면에 계산 량이 커지는 문제점 때문에 본 논문에서는 type-2 fuzzy set 대신에 secondary membership이 interval의 형태를 갖는 interval type-2 fuzzy set을 기존의 radial basis function(RBF) neural network에 적용시킨 interval type-2 fuzzy RBF neural network를 제안한다. 제안한 알고리즘은 interval type-2 fuzzy membership function에 의하여 패턴들의 불확실성을 좀 더 잘 제어하여 기존의 RBF neural network의 성능을 향상시킬 수 있다. 본 논문에서는 제안한 알고리즘의 타당성을 보이기 위하여 여러 데이터 집합에 대한 분류 결과를 보인다.

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Neural network heterogeneous autoregressive models for realized volatility

  • Kim, Jaiyool;Baek, Changryong
    • Communications for Statistical Applications and Methods
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    • v.25 no.6
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    • pp.659-671
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    • 2018
  • In this study, we consider the extension of the heterogeneous autoregressive (HAR) model for realized volatility by incorporating a neural network (NN) structure. Since HAR is a linear model, we expect that adding a neural network term would explain the delicate nonlinearity of the realized volatility. Three neural network-based HAR models, namely HAR-NN, $HAR({\infty})-NN$, and HAR-AR(22)-NN are considered with performance measured by evaluating out-of-sample forecasting errors. The results of the study show that HAR-NN provides a slightly wider interval than traditional HAR as well as shows more peaks and valleys on the turning points. It implies that the HAR-NN model can capture sharper changes due to higher volatility than the traditional HAR model. The HAR-NN model for prediction interval is therefore recommended to account for higher volatility in the stock market. An empirical analysis on the multinational realized volatility of stock indexes shows that the HAR-NN that adds daily, weekly, and monthly volatility averages to the neural network model exhibits the best performance.

Implementation of Low-cost Autonomous Car for Lane Recognition and Keeping based on Deep Neural Network model

  • Song, Mi-Hwa
    • International Journal of Internet, Broadcasting and Communication
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    • v.13 no.1
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    • pp.210-218
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    • 2021
  • CNN (Convolutional Neural Network), a type of deep learning algorithm, is a type of artificial neural network used to analyze visual images. In deep learning, it is classified as a deep neural network and is most commonly used for visual image analysis. Accordingly, an AI autonomous driving model was constructed through real-time image processing, and a crosswalk image of a road was used as an obstacle. In this paper, we proposed a low-cost model that can actually implement autonomous driving based on the CNN model. The most well-known deep neural network technique for autonomous driving is investigated and an end-to-end model is applied. In particular, it was shown that training and self-driving on a simulated road is possible through a practical approach to realizing lane detection and keeping.

An Implementation of High-Speed Parallel Processing System for Neural Network Design by Using the Multicomputer Network (다중 컴퓨터 망에서 신경회로망 설계를 위한 고속병렬처리 시스템의 구현)

  • 김진호;최흥문
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.30B no.5
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    • pp.120-128
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    • 1993
  • In this paper, an implementation of high-speed parallel processing system for neural network design on the multicomputer network is presented. Linear speedup expandability is increased by reducing the synchronization penalty and the communication overhead. Also, we presented the parallel processing models and their performance evaluation models for each of the parallization methods of the neural network. The results of the experiments for the character recognition of the neural network bases on the proposed system show that the proposed approach has the higher linear speedup expandability than the other systems. The proposed parallel processing models and the performance evaluation models could be used effectively for the design and the performance estimation of the neural network on the multicomputer network.

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Simulator Output Knowledge Analysis Using Neural network Approach : A Broadand Network Desing Example

  • Kim, Gil-Jo;Park, Sung-Joo
    • Proceedings of the Korea Society for Simulation Conference
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    • 1994.10a
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    • pp.12-12
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    • 1994
  • Simulation output knowledge analysis is one of problem-solving and/or knowledge adquistion process by investgating the system behavior under study through simulation . This paper describes an approach to simulation outputknowldege analysis using fuzzy neural network model. A fuzzy neral network model is designed with fuzzy setsand membership functions for variables of simulation model. The relationship between input parameters and output performances of simulation model is captured as system behavior knowlege in a fuzzy neural networkmodel by training examples form simulation exepreiments. Backpropagation learning algorithms is used to encode the knowledge. The knowledge is utilized to solve problem through simulation such as system performance prodiction and goal-directed analysis. For explicit knowledge acquisition, production rules are extracted from the implicit neural network knowledge. These rules may assit in explaining the simulation results and providing knowledge base for an expert system. This approach thus enablesboth symbolic and numeric reasoning to solve problem througth simulation . We applied this approach to the design problem of broadband communication network.

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A New Type of the Elmaln Neural Network (새로운 형태의 Elman 신경회로망)

  • 최우승;김주동
    • Journal of the Korea Society of Computer and Information
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    • v.4 no.1
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    • pp.62-67
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    • 1999
  • The neural network is a static network that consists of a number of layer: input layer, output layer and one or more hidden layer connected in a feed forward way. The popularity of neural network appear to be its ability of learning and approximation capability. The Elman Neural Network proposed the J. Elman, is a type of recurrent network. Is has the feedback links from hidden layer to context layer. So Elman Neural Network is the better performance than the neural network. In this paper. we propose the Modified Elman Neural Network. The structure of a MENN is based on the basic ENN. The recurrency of the network is due to the feedback links from the output layer and the hidden layer to the context layer. In order to certify the usefulness of the proposed method, the MENN apply to the X-Y cartesian tracking system. Simulation shows that the proposed MENN method is better performance than the multi layer neural network and ENN.

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