• Title/Summary/Keyword: Kohonen neural networks

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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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Application of Neural Networks to Short-Term Load Forecasting Using Electrical Load Pattern (전력부하의 유형별 단기부하예측에 신경회로망의 적용)

  • Park, Hu-Sik;Mun, Gyeong-Jun;Kim, Hyeong-Su;Hwang, Ji-Hyeon;Lee, Hwa-Seok;Park, Jun-Ho
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.1
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    • pp.8-14
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    • 1999
  • This paper presents the methods of short-term load forecasting Kohonen neural networks and back-propagation neural networks. First, historical load data is divided into 5 patterns for the each seasonal data using Kohonen neural networks and using these results, load forecasting neural network is used for next day hourly load forecasting. Next day hourly load of weekdays and weekend except holidays are forecasted. For load forecasting in summer, max-temperature and min-temperature data as well as historical hourly load date are used as inputs of load forecasting neural networks for a better forecasting accuracy. To show the possibility of the proposed method, it was tested with hourly load data of Korea Electric Power Corporation(1994-95).

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Flood Stage Forecasting using Class Segregation Method of Time Series Data (시계열자료의 계층분리기법을 이용한 하천유역의 홍수위 예측)

  • Kim, Sung-Weon
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.669-673
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    • 2008
  • In this study, the new methodology which combines Kohonen self-organizing map(KSOM) neural networks model and the conventional neural networks models such as feedforward neural networks model and generalized neural networks model is introduced to forecast flood stage in Nakdong river, Republic of Korea. It is possible to train without output data in KSOM neural networks model. KSOM neural networks model is used to classify the input data before it combines with the conventional neural networks model. Four types of models such as SOM-FFNNM-BP, SOM-GRNNM-GA, FFNNM-BP, and GRNNM-GA are used to train and test performances respectively. From the statistical analysis for training and testing performances, SOM-GRNNM-GA shows the best results compared with the other models such as SOM-FFNNM-BP, FFNNM-BP, and GRNNM-GA and FFNNM-BP shows vice-versa. From this study, we can suggest the new methodology to forecast flood stage and construct flood warning system in river basin.

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An Application of Kohonen Neural Networks to Dynamic Security Assessment (전력계통 동태 안전성 평가에 코호넨 신경망 적용 연구)

  • Lee, Gwang-Ho;Park, Yeong-Mun;Kim, Gwang-Won;Park, Jun-Ho
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.49 no.6
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    • pp.253-258
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    • 2000
  • This paper presents an application of Kohonen neural networks to assess the dynamic security of power systems. The dynamic security assessment(DSA) is an important factor in power system operation, but conventional techniques have not achieved the desired speed and accuracy. The critical clearing time(CCT) is an attribute which provides significant information about the quality of the post-fault system behaviour. The function of Kohonen networks is a mapping of the pre-fault system conditions into the neurons based on the CCTs. The power flow on each line is used as the input data, and an activated output neuron has information of the CCT of each contingency. The trajectory of the activated neurons during load changes can be used in on-line DSA efficiently. The applicability of the proposed method is demonstrated using a 9-bus example.

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Flood Stage Forecasting using Kohonen Self-Organizing Map (코호넨 자기조직화함수를 이용한 홍수위 예측)

  • Kim, Seong-Won;Kim, Hyeong-Su
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.1427-1431
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    • 2007
  • In this study, the new methodology which combines Kohonen self-organizing map(KSOM) neural networks model and the conventional neural networks models such as feedforward neural networks model and generalized neural networks model is introduced to forecast flood stage in Nakdong river, Republic of Korea. It is possible to train without output data in KSOM neural networks model. KSOM neural networks model is used to classify the input data before it combines with the conventional neural networks model. Four types of models such as SOM-FFNNM-BP, SOM-GRNNM-GA, FFNNM-BP, and GRNNM-GA are used to train and test performances respectively. From the statistical analysis for training and testing performances, SOM-GRNNM-GA shows the best results compared with the other models such as SOM-FFNNM-BP, FFNNM-BP, and GRNNM-GA and FFNNM-BP shows vice-versa. From this study, we can suggest the new methodology to forecast flood stage and construct flood warning system in river basin.

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Trajectory Estimation of a Moving Object using Kohonen Networks

  • Ju, Jin-Hwa;Lee, Dong-Hui;Lee, Jae-Ho;Lee, Jang-Myung
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.2033-2036
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    • 2004
  • A novel approach to estimate the real time moving trajectory of an object is proposed in this paper. The object position is obtained from the image data of a CCD camera, while a state estimator predicts the linear and angular velocities of the moving object. To overcome the uncertainties and noises residing in the input data, a Kalman filter and neural networks are utilized. Since the Kalman filter needs to approximate a non-linear system into a linear model to estimate the states, there always exist errors as well as uncertainties again. To resolve this problem, the neural networks are adopted in this approach, which have high adaptability with the memory of the input-output relationship. Kohonen Network(Self-Organized Map) is selected to learn the motion trajectory since it is spatially oriented. The superiority of the proposed algorithm is demonstrated through the real experiments.

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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

  • Kim, Jong-Young;Hwang, Jung-Ku;Jang, Tae-Jeong
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.63.5-63
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    • 2001
  • In this paper, moving objects tracking and dynamic characteristic analysis are studied. Kohonen´s self-organizing neural network models are used for 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.

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Development of Electric Load Forecasting System Using Neural Network (신경회로망을 이용한 단기전력부하 예측용 시스템 개발)

  • Kim, H.S.;Mun, K.J.;Hwang, G.H.;Park, J.H.;Lee, H.S.
    • Proceedings of the KIEE Conference
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    • 1999.07c
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    • pp.1522-1522
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    • 1999
  • This paper proposes the methods of short-term load forecasting using Kohonen neural networks and back-propagation neural networks. Historical load data is divided into 5 patterns for the each seasonal data using Kohonen neural networks and using these results, load forecasting neural network is used for next day hourly load forecasting. Normal days and holidays are forecasted. For load forecasting in summer, max-, and min-temperature data are included in neural networks for a better forecasting accuracy. To show the possibility of the proposed method, it was tested with hourly load data of Korea Electric Power Corporation. (1993-1997)

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Short Term Load Forecasting Using The Kohonen Neural Network (코호넨 신경망을 이용한 단기 전력수요 예측)

  • Cho, Sung-Woo;Hwang, Kab-Ju
    • Proceedings of the KIEE Conference
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    • 1996.11a
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    • pp.447-449
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    • 1996
  • This paper describes an algorithm for short term load forecasting using the Kohonen neural network. Single layer Kohonen neural network presents a lot of advantageous features for practical application. It takes less training time compared to other networks such as BP network, and moreover, its self organized feature can amend the distorted data. The originality of proposed approach is to use a Kohonen map toclassify data representing load patterns and to use directly the information stored in the weight vectors of the Kohonen map to pridict the load. Proposed method was tested with KEPCO hourly record(1993-1995) show better forecasting results compared with conventional exponential smoothing method.

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A Study of Data Mining Techniques in Bankruptcy Prediction (데이터 마이닝 기법의 기업도산예측 실증분석)

  • Lee, Kidong
    • Journal of the Korean Operations Research and Management Science Society
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    • v.28 no.2
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    • pp.105-127
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    • 2003
  • In this paper, four different data mining techniques, two neural networks and two statistical modeling techniques, are compared in terms of prediction accuracy in the context of bankruptcy prediction. In business setting, how to accurately detect the condition of a firm has been an important event in the literature. In neural networks, Backpropagation (BP) network and the Kohonen self-organizing feature map, are selected and compared each other while in statistical modeling techniques, discriminant analysis and logistic regression are also performed to provide performance benchmarks for the neural network experiment. The findings suggest that the BP network is a better choice among the data mining tools compared. This paper also identified some distinctive characteristics of Kohonen self-organizing feature map.