• 제목/요약/키워드: Back-propagation network

검색결과 1,105건 처리시간 0.036초

Application of Neural Networks For Estimating Evapotranspiration

  • Lee, Nam-Ho
    • 한국농업기계학회:학술대회논문집
    • /
    • 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
    • /
    • pp.1273-1281
    • /
    • 1993
  • Estimation of daily and seasonal evaportranspiration is essential for water resource planning irrigation feasibility study, and real-time irrigation water management . This paper is to evaluate the applicability of neural networks to the estimation of evapotranspiration . A neural network was developed to forecast daily evapotranspiration of the rice crop. It is a three-layer network with input, hidden , and output layers. Back-propagation algorithm with delta learning rule was used to train the neural network. Training neural network wasconducted usign daily actural evapotranspiration of rice crop and daily climatic data such as mean temperature, sunshine hours, solar radiation, relative humidity , and pan evaporation . During the training, neural network parameters were calibrated. The trained network was applied to a set of field data not used in the training . The created response of the neural network was in good agreement with desired values. Evaluating the neural networ performance indicates that neural network may be applied to the estimation of evapotranspiration of the rice crop.

  • PDF

혼합형 학습규칙 신경 회로망을 이용한 제어 방식 (Control Method using Neural Network of Hybrid Learning Rule)

  • 임중규;이현관;권성훈;엄기환
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국해양정보통신학회 1999년도 춘계종합학술대회
    • /
    • pp.370-374
    • /
    • 1999
  • 본 논문에서는 역전파 알고리즘과 헵 학습규칙의 장점을 최대한 살려 이용하고, 역전파 알고리즘의 문제점인 지역 최소점에 빠지는 경우와 학습시간이 느린 단점과 헵 학습규칙의 문제점인 학습 패턴의 저장능력이 매우 제한되고 선형적 분리가 되지 않는 복잡한 문제에는 적용할 수 없다는 단점등을 개선하기 위하여 혼합형 학습규칙을 제안한다. 제안하는 학습규칙은 입력층과 은닉층에 흔합형 학습규칙과 은닉층과 출력층에 역전파(Back-Propagation) 학습규칙을 적용한 혼합형이다. 제안한 혼합형 학습규칙을 이용한 신경회로망의 유용성을 확인하기 위하여 단일관절 매니플레이터를 이용하여 추종제어에 대한 시뮬레이션을 하여 기존의 역전파 알고리즘을 이용한 직접적응 제어 방식과 제어성능을 비교 검토한 결과 다음과 같은 특성을 확인하였다.

  • PDF

인공신경망기법에 상관계수를 고려한 서울 강우관측 지점 간의 강우보완 및 예측 (Rainfall Adjust and Forecasting in Seoul Using a Artificial Neural Network Technique Including a Correlation Coefficient)

  • 안정환;정희선;박인찬;조원철
    • 한국방재학회:학술대회논문집
    • /
    • 한국방재학회 2008년도 정기총회 및 학술발표대회
    • /
    • pp.101-104
    • /
    • 2008
  • In this study, rainfall adjust and forecasting using artificial neural network(ANN) which includes a correlation coefficient is application in Seoul region. It analyzed one-hour rainfall data which has been reported in 25 region in seoul during from 2000 to 2006 at rainfall observatory by AWS. The ANN learning algorithm apply for input data that each region using cross-correlation will use the highest correlation coefficient region. In addition, rainfall adjust analyzed the minimum error based on correlation coefficient and determination coefficient related to the input region. ANN model used back-propagation algorithm for learning algorithm. In case of the back-propagation algorithm, many attempts and efforts are required to find the optimum neural network structure as applied model. This is calculated similar to the observed rainfall that the correlation coefficient was 0.98 in missing rainfall adjust at 10 region. As a result, ANN model has been for suitable for rainfall adjust. It is considered that the result will be more accurate when it includes climate data affecting rainfall.

  • PDF

초타원 가우시안 소속함수를 사용한 퍼지신경망 모델링 (Fuzzy neural network modeling using hyper elliptic gaussian membership functions)

  • 권오국;주영훈;박진배
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
    • /
    • pp.442-445
    • /
    • 1997
  • We present a hybrid self-tuning method of fuzzy inference systems with hyper elliptic Gaussian membership functions using genetic algorithm(GA) and back-propagation algorithm. The proposed self-tuning method has two phases : one is the coarse tuning process based on GA and the other is the fine tuning process based on back-propagation. But the parameters which is obtained by a GA are near optimal solutions. In order to solve the problem in GA applications, it uses a back-propagation algorithm, which is one of learning algorithms in neural networks, to finely tune the parameters obtained by a GA. We provide Box-Jenkins time series to evaluate the advantage and effectiveness of the proposed approach and compare with the conventional method.

  • PDF

신경회로망을 이용한 AUV의 시스템 동정화 및 응용 (System Idenification of an Autonomous Underwater Vehicle and Its Application Using Neural Network)

  • 이판묵;이종식
    • 한국해양공학회지
    • /
    • 제8권2호
    • /
    • pp.131-140
    • /
    • 1994
  • Dynamics of AUV has heavy nonlinearities and many unknown parameters due to its bluff shape and low cruising speed. Intelligent algorithms, therefore, are required to overcome these nonlinearities and unknown system dynamics. Several identification techniques have been suggested for the application of control of underwater vehicles during last decade. This paper applies the neural network to identification and motion control problem of AUVs. Nonlinear dynamic systems of an AUV are identified using feedforward neural network. Simulation results show that the learned neural network can generate the motion of AUV. This paper, also, suggest an adaptive control scheme up-dates the controller weights with reference model and feedforward neural network using error back propagation.

  • PDF

퍼지-ANN 제어기를 이용한 유도전동기의 속도 추정 및 제어 (Estimation and Control of Speed of Induction Motor using Fuzzy-ANN Controller)

  • 이홍균;이정철;김종관;정동화
    • 대한전기학회논문지:시스템및제어부문D
    • /
    • 제53권8호
    • /
    • pp.545-550
    • /
    • 2004
  • This paper is proposed a fuzzy neural network controller based on the vector controlled induction motor drive system. The hybrid combination of fuzzy control and neural network will produce a powerful representation flexibility and numerical processing capability. Also, this paper is proposed estimation and control of speed of induction motor using ANN Controller. The back propagation neural network technique is used to provide a real time adaptive estimation of the motor speed. The error between the desired state variable and the actual one is back-propagated to adjust the rotor speed, so that the actual state variable will coincide with the desired one. The back propagation mechanism is easy to derive and the estimated speed tracks precisely the actual motor speed. This paper is proposed the theoretical analysis as well as the simulation results to verify the effectiveness of the new method.

신경망을 이용한 냉간 단조품의 기하학적 형상 및 연성파괴 예측 (The Prediction of Geometrical Configuration and Ductile Fracture Using the Artificial Neural network for a Cold Forged Product)

  • Kim, D.J.;Ko, D.C.;Park, J.C.
    • 한국정밀공학회지
    • /
    • 제13권10호
    • /
    • pp.105-111
    • /
    • 1996
  • This paper suggests the scheme to simultaneously accomplish prediction of fracture initiation and geomeytical configuration of deformation in metal forming processes using the artificial neural network. A three-layer neural network is used and a back propagation algorithm is adapted to train the network. The Cookcroft-Lathjam criterion is used to estimate whether fracture occurs during the deformation process. The geometrical configuration and the value of ductile fracture are measured by finite element method. The predictions of neural network and numerical results of simple upsetting are compared. The proposed scheme has successfully predicted the geometrical configuration and fracture initiation.

  • PDF

퍼지-뉴럴 제어기법에 의한 궤도차량의 동적 제어 (Dynamic Control of Track Vehicle Using Fuzzy-Neural Control Method)

  • 한성현;서운학;조길수;윤강섭
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 1997년도 춘계학술대회 논문집
    • /
    • pp.133-139
    • /
    • 1997
  • This paper presents a new approach to the dynamic control technique for track vehicle system using neural network-fuzzy control method. The proposed control scheme uses a Gaussian function as a unit function in the neural network-fuzzy, and back propagation algorithm to train the fuzzy-neural network controller in the framework of the specialized learning architecture. It is propored a learning controller consisting of two neural network-fuzzy based on independent resoning and a connection net with fixed weights to simply the neural network-fuzzy. The performance of the proposed controller is shown by simulation for trajectory tracking of the speed and azimuth of a track vehicle

  • PDF

인공신경망을 이용한 압밀거동 예측 (Estimating a Consolidation Behavior of Clay Using Artificial Neural Network)

  • 박형규;강명찬;이송
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2000년도 가을 학술발표회 논문집
    • /
    • pp.673-680
    • /
    • 2000
  • Artificial neural networks are efficient computing techniques that are widely used to solve complex problems in many fields. In this study, a back-propagation neural network model for estimating a consolidation behavior of clay from soil parameter, site investigation data and the first settlement curve is proposed. The training and testing of the network were based on a database of 63 settlement curve from two different sites. Five different network models were used to study the ability of the neural network to predict the desired output to increasing degree of accuracy. The study showed that the neural network model predicted a consolidation behavior of clay reasonably well.

  • PDF

BP와 PSO형 신경회로망을 이용한 선삭작업에서의 표면조도와 전류소모의 예측 (Prediction of Surface Roughness and Electric Current Consumption in Turning Operation using Neural Network with Back Propagation and Particle Swarm Optimization)

  • ;오수철
    • 한국기계가공학회지
    • /
    • 제14권3호
    • /
    • pp.65-73
    • /
    • 2015
  • This paper presents a method of predicting the machining parameters on the turning process of low carbon steel using a neural network with back propagation (BP) and particle swarm optimization (PSO). Cutting speed, feed rate, and depth of cut are used as input variables, while surface roughness and electric current consumption are used as output variables. The data from experiments are used to train the neural network that uses BP and PSO to update the weights in the neural network. After training, the neural network model is run using test data, and the results using BP and PSO are compared with each other.