• 제목/요약/키워드: Dynamic neural network

검색결과 784건 처리시간 0.035초

DNU에 의한 비선형 동적시스템의 적응제어 (Adaptive Control of Non-linearity Dynamic System using DNU)

  • 조현섭;김희숙
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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    • pp.533-536
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    • 1998
  • The intent of this paper is to describe a neural network structure called dynamic neural processor(DNP), and examine how it can be used in developing a learning scheme for computing robot inverse kinematic transformations. The architecture and learning algorithm of the proposed dynamic neural network structure, the DNP, are described. Computer simulations are provided to demonstrate the effectiveness of the proposed learning using the DNP.

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신경회로망을 이용한 원자력발전소 증기발생기의 모델링 (Modeling of Nuclear Power Plant Steam Generator using Neural Networks)

  • 이재기;최진영
    • 제어로봇시스템학회논문지
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    • 제4권4호
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    • pp.551-560
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    • 1998
  • This paper presents a neural network model representing complex hydro-thermo-dynamic characteristics of a steam generator in nuclear power plants. The key modeling processes include training data gathering process, analysis of system dynamics and determining of the neural network structure, training process, and the final process for validation of the trained model. In this paper, we suggest a training data gathering method from an unstable steam generator so that the data sufficiently represent the dynamic characteristics of the plant over a wide operating range. In addition, we define the inputs and outputs of neural network model by analyzing the system dimension, relative degree, and inputs/outputs of the plant. Several types of neural networks are applied to the modeling and training process. The trained networks are verified by using a class of test data, and their performances are discussed.

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확률신경망을 이용한 구조물 손상평가-철도교 적용 (Structural Damage Assessment Based on PNN -Application to Railway Bridge)

  • 조효남;이성칠;오달수;최윤석
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2002년도 가을 학술발표회 논문집
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    • pp.321-329
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    • 2002
  • Artificial neural network has been used for damage assessment by many researchers, but there are still some barriers that must be overcome to improve its accuracy and efficiency. The major problems with the conventional neural network are the necessity of many training patterns for neural network teaming process and ambiguity in the relationship of neural network structure to the convergence of solution. In this paper, the PNN is used as a pattern classifier to detect the damages of the railway bridge using dynamic response. The comparison between the mode shape and the natural frequency of structure as training pattern is investigated for approriate selection of the training pattern in the damage detection of railway bridge using the PNN.

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A Video Expression Recognition Method Based on Multi-mode Convolution Neural Network and Multiplicative Feature Fusion

  • Ren, Qun
    • Journal of Information Processing Systems
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    • 제17권3호
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    • pp.556-570
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    • 2021
  • The existing video expression recognition methods mainly focus on the spatial feature extraction of video expression images, but tend to ignore the dynamic features of video sequences. To solve this problem, a multi-mode convolution neural network method is proposed to effectively improve the performance of facial expression recognition in video. Firstly, OpenFace 2.0 is used to detect face images in video, and two deep convolution neural networks are used to extract spatiotemporal expression features. Furthermore, spatial convolution neural network is used to extract the spatial information features of each static expression image, and the dynamic information feature is extracted from the optical flow information of multiple expression images based on temporal convolution neural network. Then, the spatiotemporal features learned by the two deep convolution neural networks are fused by multiplication. Finally, the fused features are input into support vector machine to realize the facial expression classification. Experimental results show that the recognition accuracy of the proposed method can reach 64.57% and 60.89%, respectively on RML and Baum-ls datasets. It is better than that of other contrast methods.

신경회로망을 이용한 밀링 공정의 진동 예측 (Vibration Prediction in Milling Process by Using Neural Network)

  • 이신영
    • 한국공작기계학회논문집
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    • 제12권5호
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    • pp.1-7
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    • 2003
  • In order to predict vibrations occurred during end-milling processes, the cutting dynamics was modelled by using neural network and combined with structural dynamics by considering dynamic cutting state. Specific cutting force constants of the cutting dynamics model were obtained by averaging cutting forces. Tool diameter, cutting speed, fled, axial and radial depth of cut were considered as machining factors in neural network model of cutting dynamics. Cutting farces by test and by neural network simulation were compared and the vibration displacement during end-milling was simulated.

인공신경망을 이용한 MR댐퍼의 동특성 모델링 (Dynamic Characteristics Modeling for A MR Damper using Artifical Neural Network)

  • 백운경;이종석;손정현
    • 한국자동차공학회논문집
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    • 제12권3호
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    • pp.170-176
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    • 2004
  • MR dampers show highly nonlinear and histeretic dynamic behavior. Therefore, for a vehicle dynamic simulation with MR dampers, this dynamic characteristics should be accurately reflected in the damper model. In this paper, an artificial neural network technique was developed for modeling MR dampers. This MR damper model was successfully verified through a random input forcing test. This MR damper model can be used for semi-active suspension vehicle dynamics and control simulations with practical accuracy.

시스템의 불확실성에 대한 신경망 모델을 통한 강인한 비선형 제어 (A Robust Nonlinear Control Using the Neural Network Model on System Uncertainty)

  • 이수영;정명진
    • 대한전기학회논문지
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    • 제43권5호
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    • pp.838-847
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    • 1994
  • Although there is an analytical proof of modeling capability of the neural network, the convergency error in nonlinearity modeling is inevitable, since the steepest descent based practical larning algorithms do not guarantee the convergency of modeling error. Therefore, it is difficult to apply the neural network to control system in critical environments under an on-line learning scheme. Although the convergency of modeling error of a neural network is not guatranteed in the practical learning algorithms, the convergency, or boundedness of tracking error of the control system can be achieved if a proper feedback control law is combined with the neural network model to solve the problem of modeling error. In this paper, the neural network is introduced for compensating a system uncertainty to control a nonlinear dynamic system. And for suppressing inevitable modeling error of the neural network, an iterative neural network learning control algorithm is proposed as a virtual on-line realization of the Adaptive Variable Structure Controller. The efficiency of the proposed control scheme is verified from computer simulation on dynamics control of a 2 link robot manipulator.

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신경망을 이용한 코히런트발전기의 선정 (Identification of coherent generators for dynamic equivalents using artificial neural network)

  • 임성정;한성호;윤용한;김재철
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
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    • pp.3-5
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    • 1993
  • This paper presents a identification techniques of coherent generators for dynamic equivalents using artificial neural networks. In the developed neural network, inputs are the power system parameters which have a property of coherency. Outputs of the neural network are coherency and error indices which are derived from density measure concept. The learning of developed neural network is carried out by means of error back-propagation algorithm. Identification of coherent generators are implemented by proposed grouping algorithm using coherency and error indices. The proposed method is confirmed by simulations for 39-bus New England system.

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궤도차량의 지능제어 및 3D 시률레이터 개발 (Development of a 3D Simulator and Intelligent Control of Track Vehicle)

  • 장영희;신행봉;정동연;서운학;한성현;고희석
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1998년도 춘계학술대회 학술발표 논문집
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    • pp.107-111
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    • 1998
  • This paper presents a now approach to the design of intelligent contorl system for track vehicle system using fuzzy logic based on neural network. 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. Moreover, We develop a Windows 95 version dynamic simulator which can simulate a track vehicle model in 3D graphics space. It is proposed a learning controller consisting of two neural network-fuzzy based of independent reasoning and a connection net with fixed weights to simply the neural networks-fuzzy. The dynamic simulator for track vehicle is developed by Microsoft Visual C++. Graphic libraries, OpenGL, by Silicon Graphics, Inc. were utilized for 3D Graphics. The performance of the proposed controller is illustrated by simulation for trajectory tracking of track vehicle speed.

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순환 신경망을 이용한 보행단계 분류기 (A Gait Phase Classifier using a Recurrent Neural Network)

  • 허원호;김은태;박현섭;정준영
    • 제어로봇시스템학회논문지
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    • 제21권6호
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    • pp.518-523
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    • 2015
  • This paper proposes a gait phase classifier using a Recurrent Neural Network (RNN). Walking is a type of dynamic system, and as such it seems that the classifier made by using a general feed forward neural network structure is not appropriate. It is known that an RNN is suitable to model a dynamic system. Because the proposed RNN is simple, we use a back propagation algorithm to train the weights of the network. The input data of the RNN is the lower body's joint angles and angular velocities which are acquired by using the lower limb exoskeleton robot, ROBIN-H1. The classifier categorizes a gait cycle as two phases, swing and stance. In the experiment for performance verification, we compared the proposed method and general feed forward neural network based method and showed that the proposed method is superior.