• Journal of the Korean Society for Precision Engineering
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• v.14 no.10
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• pp.141-150
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• 1997

분산은 확률모델을 표현하는 유용한 변수중 하나이다. 입력변수에 대한 함수로 표현되는 조건부 분산을 학습하는 신경회로망에 대한 많은 연구가 있어왔다. VALEAN이라는 신경회로망 역시 이러한 많은 연구중 하나인데 이것은 기본적으로 feedforward 다층 퍼셉트론 구조를 가지며 새롭게 제시된 에너지 함수를 사용하고 있다. 이 논문에서는 이 에너지 모델에 의해 결정되는 피드백에러(델타)가 신경망의 transient, steady state에서 미치는 영향을 다루었다. 과도 상태 분석에서는 델타와 수렴성, 안정성에 관한 내용을 다루고 모의 실험을 하였으며 정상 상태 분석에서는 신경회로망의 정상상태 에러의 크기와 델타의 크기사이의 상관관계에 대하여 다루었다. 학습 알고 리듬이 확률적이므로 정상상태 역시 확률적인 상태를 나타낸다. 따라서 델타의 크기에 따른 정상 상태 에러의 최대치는 확률적인 모델을 가지게 된다. 여기서는 이 확률 관계를 분석적으로 규명하고 이에 따라 원하는 신뢰도로 정상 상태 에러를 제어하기 위해 필요한 델타의 크기를 예측할 수 있는 이론적 배경을 마련하게 된다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.9
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• pp.738-744
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• 1990

This paper proposed a real-time memory storage method and an improved sample data method from given data of the speech signal, so, the isolated word recognition system using a back-propagation learning algorithm of the neural netwrok is studied. The recognition rate and the error rate are compared with the new sample data sets generated from small sets of given sample data by the node nunber variatiion of each layer. In this result, the recognition rate of 95.1% was achived.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.503-505
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• 1998

The position control of an induction motor using Feedforward Neural Networks(FNNs) was studied in this paper. A teaching signal was obtained from sliding surface without a particular signal. And the FNNs team through the back propagation algorithm so as to reduce the error between the real position of the motor and the reference value. The structure of a controller was designed simply, for the fast calculating response which is certainly necessary for induction motor position control. And to show the superiority of this controller, 3-phase vector control induction motor whose power capacity is 2.2kw was modeled, and it was simulated.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1997.11a
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• pp.267-270
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• 1997

In this paper, we proposed an optimazation method using Genetic Algorithm for nonlinear system modeling. Fuzzy Neural Network(FNNs) was used as basic model of nonlinear system. FNNs was fused of Fuzzy Inference which has linguistic property and Neural Network which has learning ability and high tolerence level. This paper, We used FNNs which was proposed by Yamakawa. The FNNs was composed Simple Inference and Error Back Propagation Algorithm. To obtain optimal model, parameter of membership function, learning rate and momentum coefficient of FNNs are tuned using genetic algorithm. And we used simplex algorithm additionaly to overcome limit of genetic algorithm. For the purpose of evaluation of proposed method, we applied proposed method to traffic choice process and waste water treatment process, and then obtained more precise model than other previous optimization methods and objective model.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1997.11a
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• pp.176-179
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• 1997

본 논문은 입/출력 관계가 불명확한 가전제품 제어에 인공신경회로망을 응용하여 지능형 제어기를 구현하는 방법에 관한 것이다. 다층신경회로망을 사용하고 Error Back Propagation 학습방법에 의하여 학습되도록 한다. 제어대상물에서 알 수 있는 정보는 입력값과 이에 대응하는 출력값 뿐이며 입력과 출력에 대한 관계를 수학적으로 모델링하기 어려운 경우이다. 인공신경회로망을 이용한 제어를 위하여 Neural Network Emulator(NNE)와 Neural Network Controller(NNC)가 개발되며 각 신경회로망의 초기하중백터는 제어대상에 오프라인 학습으로 결정하고, 자동조절과정에서 온라인 학습하여 새로운 대상제품 상황에 적응하도록 설계되었다. 제안된 지능형 제어시스템은 PC를 이용하여 실시스템에 적용하여 검토되었다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.04a
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• pp.135-140
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• 1998

본 논문에서는 신경회로망에서 가장 널리 쓰이고 있는 오차 역 전파 알고리즘(Error Back-propagation) 을 사용하여 스캐너를 모델링함으로써 스캐너의 원색 재현을 위한 방법을 제시하였다. 이것은 스캐너의 하드웨어적 특성을 고려, 입력된 영상의 원색과 출력물의 색과 일치시키는 방법이다. 우선, 오차 역전파 알고리즘에 대하여 학습 규칙을 살펴보고 학습을 위한 데이터를 추출하기 위해 고르게 분포된 색 샘플들을 계측기로 측정하여 칼라 공간에서의 X, Y, Z 값을 얻어낸다. 그 중에서 표본 샘플을 추출한다. 그리고 이를 스캐너로 스캐닝하여 얻은 R, G, B값을 오차 역전파 알고리즘의 입력값으로, 목표값은 X, Y, Z값을 사용하여 학습시킨다. 학습하는 동안 샘플 색상의 수와 중간층의 수, 노드의 수를 변화시킴으로써 최적의 결과를 얻도록 실험하였다. 결론에서는 서로간의 결과를 분석한다.

• Bulletin of the Korean Chemical Society
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• v.28 no.9
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• pp.1477-1484
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• 2007

Artificial neural networks (ANNs), for a first time, were successfully developed for the prediction partial molar heat capacity of aqueous solutions at infinite dilution for various polar aromatic compounds over wide range of temperatures (303.55-623.20 K) and pressures (0.1-30.2 MPa). Two three-layered feed forward ANNs with back-propagation of error were generated using three (the heat capacity in T = 303.55 K and P = 0.1 MPa, temperature and pressure) and six parameters (four theoretical descriptors, temperature and pressure) as inputs and its output is partial molar heat capacity at infinite dilution. It was found that properly selected and trained neural networks could fairly represent dependence of the heat capacity on the molecular descriptors, temperature and pressure. Mean percentage deviations (MPD) for prediction set by the models are 4.755 and 4.642, respectively.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.1
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• pp.40-45
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• 2016

This paper presents the neuro-fuzzy control method for balancing a two-wheel mobile robot. A two-wheel mobile robot is built for the experimental studies. On-line learning algorithm based on the back-propagation(BP) method is derived for the Takagi-Sugeno(T-S) neuro-fuzzy controller. The modified error is proposed to learn the B-P algorithm for the balancing control of a two-wheel mobile robot. The T-S controller is implemented on a DSP chip. Experimental studies of the balancing control performance are conducted. Balancing control performances with disturbance are also conducted and results are evaluated.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.28B no.11
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• pp.934-940
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• 1991

The multi-layer neural network that has broadly been utilized in designing the controller of robot manipulator possesses the desirable characteristics of learning capacity, by which the uncertain variation of the dynamic parameters of robot can be handled adaptively, and parallel distributed processing that makes it possible to control on real-time. However the error back propagation algorithm that has been utilized popularly in the learning of the multi-layer neural network has the problem of its slow convergencs speed. In this paper, an approach to improve the convergence speed is proposed using fuzzy logic that can effectively handle the uncertain and fuzzy informations by linguistic level. The effectiveness of the proposed algorithm is demonstrated by computer simulation of PUMA 560 robot manipulator.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.11
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• pp.56-65
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• 1993

This paper presents the design consideration of the MFNNs(Multilayer Feed forward Neural Networks) based on the distribution of the given teching patterns. By extracting the feature points from the given teaching patterns, the structure of a network including the netowrk size and interconnection weights of a network is initialized. This network is trained based on the modified version of the EBP(Error Back Propagation) algorithm. As a result, the proposed method has the advantage of learning speed compared to the conventional learning of the MFNNs with randomly chosen initial weights. To show the effectiveness of the suggested approach, the simulation result on the approximation of a two demensional continuous function is shown.