• Title/Summary/Keyword: neural network.

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Identification of Dynamic Systems Using a Self Recurrent Wavelet Neural Network: Convergence Analysis Via Adaptive Learning Rates (자기 회귀 웨이블릿 신경 회로망을 이용한 다이나믹 시스템의 동정: 적응 학습률 기반 수렴성 분석)

  • Yoo, Sung-Jin;Choi, Yoon-Ho;Park, Jin-Bae
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.9
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    • pp.781-788
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    • 2005
  • This paper proposes an identification method using a self recurrent wavelet neural network (SRWNN) for dynamic systems. The architecture of the proposed SRWNN is a modified model of the wavelet neural network (WNN). But, unlike the WNN, since a mother wavelet layer of the SRWNN is composed of self-feedback neurons, the SRWNN has the ability to store the past information of the wavelet. Thus, in the proposed identification architecture, the SRWNN is used for identifying nonlinear dynamic systems. The gradient descent method with adaptive teaming rates (ALRs) is applied to 1.am the parameters of the SRWNN identifier (SRWNNI). The ALRs are derived from the discrete Lyapunov stability theorem, which are used to guarantee the convergence of an SRWNNI. Finally, through computer simulations, we demonstrate the effectiveness of the proposed SRWNNI.

Applications of Fuzzy Logic and Neural Network Technology to Flight Control System Design: an Overview (퍼지논리 및 신경회로망 기법을 적용한 비행제어시스템 설계 고찰)

  • 홍성경;김병수
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.2
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    • pp.103-111
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    • 2004
  • In this survey paper, we attempt to introduce the subjects of fuzzy logic and neural network technology for flight control systems based on completed and ongoing research programs other developed countries. Also, it is prepared with intention of providing the reader with an overview of related topics and a basic concepts of fuzzy logic and neural network control. The focus is on relatively practical control schemes realistically applicable in the area of flight control system design that could find its usage in the near future in our country. It is hoped that this paper will serve as a useful reference and even concepts provide solutions far current problems and future designs.

Parity Discrimination by Perceptron Neural Network (퍼셉트론형 신경회로망에 의한 패리티판별)

  • Choi, Jae-Seung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.3
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    • pp.565-571
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    • 2010
  • This paper proposes a parity discrimination algorithm which discriminates N bit parity using a perceptron neural network and back propagation algorithm. This algorithm decides minimum hidden unit numbers when discriminates N bit parity. Therefore, this paper implements parity discrimination experiments for N bit by changing hidden unit numbers of the proposed perceptron neural network. Experiments confirm that the proposed algorithm is possible to discriminates N bit parity.

Combination Tandem Architecture with Segmental Features for Robust Speech Recognition (강인한 음성 인식을 위한 탠덤 구조와 분절 특징의 결합)

  • Yun, Young-Sun;Lee, Yun-Keun
    • MALSORI
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    • no.62
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    • pp.113-131
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    • 2007
  • It is reported that the segmental feature based recognition system shows better results than conventional feature based system in the previous studies. On the other hand, the various studies of combining neural network and hidden Markov models within a single system are done with expectations that it may potentially combine the advantages of both systems. With the influence of these studies, tandem approach was presented to use neural network as the classifier and hidden Markov models as the decoder. In this paper, we applied the trend information of segmental features to tandem architecture and used posterior probabilities, which are the output of neural network, as inputs of recognition system. The experiments are performed on Auroral database to examine the potentiality of the trend feature based tandem architecture. From the results, the proposed system outperforms on very low SNR environments. Consequently, we argue that the trend information on tandem architecture can be additionally used for traditional MFCC features.

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An Integrated Neural Network Model for Domain Action Determination in Goal-Oriented Dialogues

  • Lee, Hyunjung;Kim, Harksoo;Seo, Jungyun
    • Journal of Information Processing Systems
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    • v.9 no.2
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    • pp.259-270
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    • 2013
  • A speaker's intentions can be represented by domain actions (domain-independent speech act and domain-dependent concept sequence pairs). Therefore, it is essential that domain actions be determined when implementing dialogue systems because a dialogue system should determine users' intentions from their utterances and should create counterpart intentions to the users' intentions. In this paper, a neural network model is proposed for classifying a user's domain actions and planning a system's domain actions. An integrated neural network model is proposed for simultaneously determining user and system domain actions using the same framework. The proposed model performed better than previous non-integrated models in an experiment using a goal-oriented dialogue corpus. This result shows that the proposed integration method contributes to improving domain action determination performance.

Hybrid Neural Networks for Pattern Recognition

  • Kim, Kwang-Baek
    • Journal of information and communication convergence engineering
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    • v.9 no.6
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    • pp.637-640
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    • 2011
  • The hybrid neural networks have characteristics such as fast learning times, generality, and simplicity, and are mainly used to classify learning data and to model non-linear systems. The middle layer of a hybrid neural network clusters the learning vectors by grouping homogenous vectors in the same cluster. In the clustering procedure, the homogeneity between learning vectors is represented as the distance between the vectors. Therefore, if the distances between a learning vector and all vectors in a cluster are smaller than a given constant radius, the learning vector is added to the cluster. However, the usage of a constant radius in clustering is the primary source of errors and therefore decreases the recognition success rate. To improve the recognition success rate, we proposed the enhanced hybrid network that organizes the middle layer effectively by using the enhanced ART1 network adjusting the vigilance parameter dynamically according to the similarity between patterns. The results of experiments on a large number of calling card images showed that the proposed algorithm greatly improves the character extraction and recognition compared with conventional recognition algorithms.

3D Grasp Planning using Stereo Matching and Neural Network (스테레오정합과 신경망을 이용한 3차원 잡기계획)

  • Lee, Hyun-Ki;Bae, Joon-Young;Lee, Sang-Ryong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.7
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    • pp.1110-1119
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    • 2003
  • This paper deals with the synthesis of the 3-dimensional grasp planning for unknown objects. Previous studies have many problems, which the estimation time for finding the grasping points is much long and the analysis used the not-perfect 3-dimensional modeling. To overcome these limitations in this paper new algorithm is proposed, which algorithm is achieved by two steps. First step is to find the whole 3-dimensional geometrical modeling for unknown objects by using stereo matching. Second step is to find the optimal grasping points for unknown objects by using the neural network trained by the result of optimization using genetic algorithm. The algorithm is verified by computer simulation, comparing the result between neural network and optimization.

Path planning algorithm of mobile robot using neural network model (신경회로망 모델을 이용한 이동로봇의 경로생성 알고리즘)

  • 차영엽;유창목
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1601-1604
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    • 1997
  • The most important topic in research of mobile robot is path planning in order to avoid with obstacle. In this study the path planning algorithm using a neural network model is proposed. The inputs of neural network are range data which are acquired form laser range finderm and weights are based on difference with goal direction. The thresholds are made by consdiering the marginal distance between mobile robot and obstacle. Consequently the outputs are obtained by multiplying input and weight. The obtained heading directiion enables the mobile robot to approach the goal, without any collision with obstacles around. The effectiveness of the this method of real-time navigation of a mobile robot is estimated by computer simulation in complex environment.

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Image Clustering using Improved Neural Network Algorithm (개선된 신경망 알고리즘을 이용한 영상 클러스터링)

  • 박상성;이만희;유헌우;문호석;장동식
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.7
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    • pp.597-603
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    • 2004
  • In retrieving large database of image data, the clustering is essential for fast retrieval. However, it is difficult to cluster a number of image data adequately. Moreover, current retrieval methods using similarities are uncertain of retrieval accuracy and take much retrieving time. In this paper, a suggested image retrieval system combines Fuzzy ART neural network algorithm to reinforce defects and to support them efficiently. This image retrieval system takes color and texture as specific feature required in retrieval system and normalizes each of them. We adapt Fuzzy ART algorithm as neural network which receive normalized input-vector and propose improved Fuzzy ART algorithm. The result of implementation with 200 image data shows approximately retrieval ratio of 83%.

Motion Analysis with Time Delay Neural Network (시간 지연 신경망을 이용한 동작 분석)

  • Jang, Dong-Sik;Lee, Man-Hee;Lee, Jong-Won
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.4
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    • pp.419-426
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    • 1999
  • A novel motion analysis system is presented in this paper. The proposed system is inspired by processing functions observed in the fly visual system, which detects changes in input light intensities, determines motion on both the local and the wide-field levels. The system has several differences from conventional motion analysis system. First, conventional systems usually focused on matching similar feature or optical flow, but neural network is applied in this system. Back propagation is used by learning method, and Tine Delay Neural Network (TDNN) is also used as analysis method. Second, while conventional systems usually limited on only two frames of sequence, the proposed system accept multiple frames of sequence. The experimental results showed a 94.7% correct rate with a speed of 71.47 milli seconds for real and synthetic images.

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