• 제목/요약/키워드: Kohonen

검색결과 165건 처리시간 0.028초

가변적 클러스터 개수에 대한 문서군집화 평가방법 (The Evaluation Measure of Text Clustering for the Variable Number of Clusters)

  • 조태호
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2006년도 가을 학술발표논문집 Vol.33 No.2 (B)
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    • pp.233-237
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    • 2006
  • This study proposes an innovative measure for evaluating the performance of text clustering. In using K-means algorithm and Kohonen Networks for text clustering, the number clusters is fixed initially by configuring it as their parameter, while in using single pass algorithm for text clustering, the number of clusters is not predictable. Using labeled documents, the result of text clustering using K-means algorithm or Kohonen Network is able to be evaluated by setting the number of clusters as the number of the given target categories, mapping each cluster to a target category, and using the evaluation measures of text. But in using single pass algorithm, if the number of clusters is different from the number of target categories, such measures are useless for evaluating the result of text clustering. This study proposes an evaluation measure of text clustering based on intra-cluster similarity and inter-cluster similarity, what is called CI (Clustering Index) in this article.

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

  • 김성원;김형수
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2007년도 학술발표회 논문집
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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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Logistic Regression for Investigating Credit Card Default

  • 양정원;하성호;민지홍
    • 한국산업정보학회:학술대회논문집
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    • 한국산업정보학회 2008년도 추계 공동 국제학술대회
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    • pp.164-169
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    • 2008
  • The increasing late-payment rate of credit card customers caused by a recent economic downturn are incurring not only reduced profit of department stores but also significant loss. Under this pressure, the objective of credit forecasting is extended from presumption of good or bad customers to contribution to revenue growth. As a method of managing defaults of department store credit card, this study classifies credit delinquents into some clusters, analyzes repaying patterns of customers in each cluster, and develops credit forecasting system to manage delinquents of department store credit card using data of Korean D department store's delinquents. The model presented by this study uses Kohonen network, a kind of artificial neural network of data mining techniques to cluster credit delinquents into groups. Logistic regression model is also used to predict repayment rate of customers of each cluster per period. The accuracy of presented system for the whole clusters is 92.3%.

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Kohonen 자기조직화 map 에 기반한 기계-부품군 형성 (Machine-Part Cell Formation based on Kohonen화s Self Organizing Feature Map)

  • 이경미;이건명
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1996년도 추계학술대회 학술발표 논문집
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    • pp.315-318
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    • 1996
  • The machine-part cell formation means the grouping of similar parts and similar machines into families in order to minimize bottleneck machines, bottleneck parts, and inter-cell part movements in cellular manufacturing systems and flexible manufacturing systems. The cell formation problem is knows as a kind of NP complete problems. This paper briefly introduces the cell-formation problem and proposes a cell formation method based on the Kohonen's self-organizing feature map which is a neural network model. It also shows some experiment results using the proposed method. The proposed method can be easily applied to the cell formation problem compared to other meta-heuristic based methods. In addition, it can be used to solve large-scale cell formation problems.

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신경회로망를 이용한 TCSC 적용 LQG 제어에 관한 연구 (A Study on the LQG Control of TCSC Using Neural Network)

  • 김태준;이병하
    • 대한전기학회논문지:전력기술부문A
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    • 제48권3호
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    • pp.212-219
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    • 1999
  • In this paper we present a neural network approach to select weighting matrices of Linear-Quadratic-Gaussian(LQG) controller for TCSC control. The selection of weighting matrices is usually carried out by trial and error. A weighting matrices of LQG control are selected effectively using Kohonen network. It is shown that simulation results in application of this method to three machine nine bus system are satisfactory.

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퍼셉트론 형태의 SOM : SOM의 일반화 (Perceptron-like SOM : Generalization of SOM)

  • 송근배;이행세
    • 한국정보처리학회논문지
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    • 제7권10호
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    • pp.3098-3104
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    • 2000
  • 본 논문에서는 퍼셉트론 형태의 SOM(PSOM)을 정의한다. 그리고 이 PSOM의 출력뉴런의 목표 값을 적당히 설정할 경우 PSOM은 Kohonen's SOM이 됨을 보인다. 이는 PSOM가 SOM의 일반화된 알고리즘임을 시사한다. 또한 클러스터링 문제를 단위 초구면상(Hyperphere)에 분포한 벡터들로 한정할 경우 SOM은 Dot-product SOM(DSOM)과 동등한 알고리즘임을 보인다. 즉, DSOM은 SOM의 특수한 형태이며, 결론적으로, PSOM은 DSOM도 포함하는 알고리즘이다. 본 논문에서는 이를 증명하고 결론을 맺는다.

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

  • 김성원
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2008년도 정기총회 및 학술발표대회
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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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일정적응 이득과 이진 강화함수를 갖는 경쟁 학습 신경회로망 (Competitive Learning Neural Network with Binary Reinforcement and Constant Adaptation Gain)

  • 석진욱;조성원;최경삼
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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    • pp.326-328
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    • 1994
  • A modified Kohonen's simple Competitive Learning(SCL) algorithm which has binary reinforcement function and a constant adaptation gain is proposed. In contrast to the time-varing adaptation gain of the original Kohonen's SCL algorithm, the proposed algorithm uses a constant adaptation gain, and adds a binary reinforcement function in order to compensate for the lowered learning ability of SCL due to the constant adaptation gain. Since the proposed algorithm does not have the complicated multiplication, it's digital hardware implementation is much easier than one of the original SCL.

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코호넬 신경회로망을 이용한 배전시스템의 전압/무효전력 제어게 관한 연구 (A Study on the Voltage/Var Control of Distribution System Using Kohonen Neural Network)

  • 김광원;김종일
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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    • pp.329-331
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    • 1998
  • This paper presents a modified Learning Vector Quantization rule to control shunt capacitor banks and feeder voltage regulators in electric distribution systems with Kohonen Neural Network(KNN). The objective of the KNN is on-line decision of the optimal state of shunt capacitor banks and feeder voltage regulators which minimize $I^{2}R$ losses of the distribution system while maintaining all the bus voltages within the limits. The KNN is tested on a distribution system with 30 buses, 5 on-off switchable capacitor banks and a nine tap line voltage regulator.

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Application of Soft Computing Model for Hydrologic Forecasting

  • Kim, Sung-Won;Park, Ki-Bum
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2012년도 학술발표회
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    • pp.336-339
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    • 2012
  • Accurate forecasting of pan evaporation (PE) is very important for monitoring, survey, and management of water resources. The purpose of this study is to develop and apply Kohonen self-organizing feature maps neural networks model (KSOFM-NNM) to forecast the daily PE for the dry climate region in south western Iran. KSOFM-NNM for Ahwaz station was used to forecast daily PE on the basis of temperature-based, radiation-based, and sunshine duration-based input combinations. The measurements at Ahwaz station in south western Iran, for the period of January 2002 - December 2008, were used for training, cross-validation and testing data of KSOFM-NNM. The results obtained by TEM 1 produced the best results among other combinations for Ahwaz station. Based on the comparisons, it was found that KSOFM-NNM can be employed successfully for forecasting the daily PE from the limited climatic data in south western Iran.

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