• Title/Summary/Keyword: Neural-Networks

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Forecasting of Daily Inflows Based on Regressive Neural Networks

  • Shin, Hyun-Suk;Kim, Tae-Woong;Kim, Joong-Hoon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2001.05a
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    • pp.45-51
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    • 2001
  • The daily inflow is apparently one of nonlinear and complicated phenomena. The nonlinear and complexity make it difficult to model the prediction of daily flow, but attractive to try the neural networks approach which contains inherently nonlinear schemes. The study focuses on developing the forecasting models of daily inflows to a large dam site using neural networks. In order to reduce the error caused by high or low outliers, the back propagation algorithm which is one of neural network structures is modified by combining a regression algorithm. The study indicates that continuous forecasting of a reservoir inflow in real time is possible through the use of modified neural network models. The positive effect of the modification using tole regression scheme in BP algorithm is showed in the low and high ends of inflows.

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Neural Network Modeling for the Superheated, Saturated and Compressed Region of Steam Table (증기표의 과열, 포화 및 압축영역의 신경회로망 모델링)

  • Lee, Tae-Hwan;Park, Jin-Hyun
    • Journal of the Korean Society of Mechanical Technology
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    • v.20 no.6
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    • pp.872-878
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    • 2018
  • Steam tables including superheated, saturated and compressed region were simultaneously modeled using the neural networks. Pressure and temperature were used as two inputs for superheated and compressed region. On the other hand Pressure and dryness fraction were two inputs for saturated region. The outputs were specific volume, specific enthalpy and specific entropy. The neural network model were compared with the linear interpolation model in terms of the percentage relative errors. The criterion of judgement was selected with the percentage relative error of 1%. In conclusion the neural networks showed better results than the interpolation method for all data of superheated and compressed region and specific volume of saturated region, but similar for specific enthalpy and entropy of saturated region.

Special-Days Load Handling Method using Neural Networks and Regression Models (신경회로망과 회귀모형을 이용한 특수일 부하 처리 기법)

  • 고희석;이세훈;이충식
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.16 no.2
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    • pp.98-103
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    • 2002
  • In case of power demand forecasting, the most important problems are to deal with the load of special-days. Accordingly, this paper presents the method that forecasting long (the Lunar New Year, the Full Moon Festival) and short(the Planting Trees Day, the Memorial Day, etc) special-days peak load using neural networks and regression models. long and short special-days peak load forecast by neural networks models uses pattern conversion ratio and four-order orthogonal polynomials regression models. There are using that special-days peak load data during ten years(1985∼1994). In the result of special-days peak load forecasting, forecasting % error shows good results as about 1 ∼2[%] both neural networks models and four-order orthogonal polynomials regression models. Besides, from the result of analysis of adjusted coefficient of determination and F-test, the significance of the are convinced four-order orthogonal polynomials regression models. When the neural networks models are compared with the four-order orthogonal polynomials regression models at a view of the results of special-days peak load forecasting, the neural networks models which uses pattern conversion ratio are more effective on forecasting long special-days peak load. On the other hand, in case of forecasting short special-days peak load, both are valid.

Evolving Team-Agent Based on Dynamic State Evolutionary Artificial Neural Networks (동적 상태 진화 신경망에 기반한 팀 에이전트의 진화)

  • Jin, Xiang-Hua;Jang, Dong-Heon;Kim, Tae-Yong
    • Journal of Korea Multimedia Society
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    • v.12 no.2
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    • pp.290-299
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    • 2009
  • Evolutionary Artificial Neural Networks (EANNs) has been highly effective in Artificial Intelligence (AI) and in training NPCs in video games. When EANNs is applied to design game NPCs' smart AI which can make the game more interesting, there always comes two important problems: the more complex situation NPCs are in, the more complex structure of neural networks needed which leads to large operation cost. In this paper, the Dynamic State Evolutionary Neural Networks (DSENNs) is proposed based on EANNs which deletes or fixes the connection of the neurons to reduce the operation cost in evolution and evaluation process. Darwin Platform is chosen as our test bed to show its efficiency: Darwin offers the competitive team game playing behaviors by teams of virtual football game players.

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Inference of Context-Free Grammars using Binary Third-order Recurrent Neural Networks with Genetic Algorithm (이진 삼차 재귀 신경망과 유전자 알고리즘을 이용한 문맥-자유 문법의 추론)

  • Jung, Soon-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.3
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    • pp.11-25
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    • 2012
  • We present the method to infer Context-Free Grammars by applying genetic algorithm to the Binary Third-order Recurrent Neural Networks(BTRNN). BTRNN is a multiple-layered architecture of recurrent neural networks, each of which is corresponding to an input symbol, and is combined with external stack. All parameters of BTRNN are represented as binary numbers and each state transition is performed with any stack operation simultaneously. We apply Genetic Algorithm to BTRNN chromosomes and obtain the optimal BTRNN inferring context-free grammar of positive and negative input patterns. This proposed method infers BTRNN, which includes the number of its states equal to or less than those of existing methods of Discrete Recurrent Neural Networks, with less examples and less learning trials. Also BTRNN is superior to the recent method of chromosomes representing grammars at recognition time complexity because of performing deterministic state transitions and stack operations at parsing process. If the number of non-terminals is p, the number of terminals q, the length of an input string k, and the max number of BTRNN states m, the parallel processing time is O(k) and the sequential processing time is O(km).

The optimum pattern recognition and classification using neural networks (신경망을 이용한 최적 패턴인식 및 분류)

  • Kim, J.H.;Seo, B.H.;Park, S.W.
    • Proceedings of the KIEE Conference
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    • 2004.05a
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    • pp.92-94
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    • 2004
  • We become an industry information society which is advanced to the altitude with the today. The information to be loading various goods each other together at a circumstance environment is increasing extremely. The restriction recognizes the data of many Quantity and it follows because the human deals the task to classify. The development of a mathematical formulation for solving a problem like this is often very difficult. But Artificial intelligent systems such as neural networks have been successfully applied to solving complex problems in the area of pattern recognition and classification. So, in this paper a neural network approach is used to recognize and classification problem was broken into two steps. The first step consist of using a neural network to recognize the existence of purpose pattern. The second step consist of a neural network to classify the kind of the first step pattern. The neural network leaning algorithm is to use error back-propagation algorithm and to find the weight and the bias of optimum. Finally two step simulation are presented showing the efficacy of using neural networks for purpose recognition and classification.

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Time-Series Prediction of Baltic Dry Index (BDI) Using an Application of Recurrent Neural Networks (Recurrent Neural Networks를 활용한 Baltic Dry Index (BDI) 예측)

  • Han, Min-Soo;Yu, Song-Jin
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2017.11a
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    • pp.50-53
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    • 2017
  • Not only growth of importance to understanding economic trends, but also the prediction to overcome the uncertainty is coming up for long-term maritime recession. This paper discussed about the prediction of BDI with artificial neural networks (ANN). ANN is one of emerging applications that can be the finest solution to the knotty problems that may not easy to achieve by humankind. Proposed a prediction by implementing neural networks that have recurrent architecture which are a Recurrent Neural Network (RNN) and Long Short-Term Memory (LSTM). And for the reason of comparison, trained Multi Layer Perceptron (MLP) from 2009.04.01 to 2017.07.31. Also made a comparison with conventional statistics, prediction tools; ARIMA. As a result, recurrent net, especially RNN outperformed and also could discover the applicability of LSTM to specific time-series (BDI).

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A Study on Center Detection and Motion Analysis of a Moving Object by Using Kohonen Networks and Time Delay Neural Networks (코호넨 네트워크 및 시간 지연 신경망을 이용한 움직이는 물체의 중심점 탐지 및 동작특성 분석에 관한 연구)

  • Hwang, Jung-Ku;Kim, Jong-Young;Jang, Tae-Jeong
    • Journal of Industrial Technology
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    • v.21 no.B
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    • pp.91-98
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    • 2001
  • In this paper, center detection and motion analysis of a moving object are studied. Kohonen's self-organizing neural network models are used for the moving objects tracking and time delay neural networks are used for dynamic characteristic analysis. Instead of objects brightness, neuron projections by Kohonen Networks are used. The motion of target objects can be analyzed by using the differential neuron image between the two projections. The differential neuron image which is made by two consecutive neuron projections is used for center detection and moving objects tracking. The two differential neuron images which are made by three consecutive neuron projections are used for the moving trajectory estimation. It is possible to distinguish 8 directions of a moving trajectory with two frames and 16 directions with three frames.

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The Structure of Boundary Decision Using the Back Propagation Algorithms (역전파 알고리즘을 이용한 경계결정의 구성에 관한 연구)

  • Lee, Ji-Young
    • The Journal of Information Technology
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    • v.8 no.1
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    • pp.51-56
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    • 2005
  • The Back propagation algorithm is a very effective supervised training method for multi-layer feed forward neural networks. This paper studies the decision boundary formation based on the Back propagation algorithm. The discriminating powers of several neural network topology are also investigated against five manually created data sets. It is found that neural networks with multiple hidden layer perform better than single hidden layer.

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퍼지신경망에 의한 퍼지 회귀분석: 품질 평가 문제에의 응용

  • 권기택
    • Proceedings of the Korea Association of Information Systems Conference
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    • 1996.11a
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    • pp.211-216
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    • 1996
  • This paper propose a fuzzy regression method using fuzzy neural networks when a membership value is attached to each input-output pair. First, an architecture o fuzzy neural networks with fuzzy weights and fuzzy biases is shown. Next, a cost function is defined using the fuzzy output from the fuzzy neural network and the corresponding target output with a membership value. A learning algorithm is derived from the cost function. The derived learning algorithm trains the fuzzy neural network so 솜 t the level set of the fuzzy output includes the target output. Last, the proposed method is applied to the quality evaluation problem of injection molding

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