• 제목/요약/키워드: Data Clustering

검색결과 2,731건 처리시간 0.033초

Design and Comparison of Error Correctors Using Clustering in Holographic Data Storage System

  • Kim, Sang-Hoon;Kim, Jang-Hyun;Yang, Hyun-Seok;Park, Young-Pil
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1076-1079
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    • 2005
  • Data storage related with writing and retrieving requires high storage capacity, fast transfer rate and less access time in. Today any data storage system can not satisfy these conditions, but holographic data storage system can perform faster data transfer rate because it is a page oriented memory system using volume hologram in writing and retrieving data. System architecture without mechanical actuating part is possible, so fast data transfer rate and high storage capacity about 1Tb/cm3 can be realized. In this paper, to correct errors of binary data stored in holographic digital data storage system, find cluster centers using clustering algorithm and reduce intensities of pixels around centers. We archive the procedure by two algorithms of C-mean and subtractive clustering, and compare the results of the two algorithms. By using proper clustering algorithm, the intensity profile of data page will be uniform and the better data storage system can be realized.

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홀로그래픽 정보 저장 장치에서 클러스터링을 이용한 에러 감소 기법 제안 및 비교 (Design and Comparison of Error Reduction Methods Using Clustering in Holographic Data Storage System)

  • 김상훈;김장현;양현석;박영필
    • 정보저장시스템학회:학술대회논문집
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    • 정보저장시스템학회 2005년도 추계학술대회 논문집
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    • pp.83-87
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    • 2005
  • Data storage related with writing and retrieving requires high storage capacity, fast transfer rate and less access time in. Today any data storage system can not satisfy these conditions, but holographic data storage system can perform faster data transfer rate because it is a page oriented memory system using volume hologram in writing and retrieving data. System architecture without mechanical actuating pare is possible, so fast data transfer rate and high storage capacity about 1Tb/cm3 can be realized. In this paper, to correct errors of binary data stored in holographic digital data storage system, find cluster centers using clustering algorithm and reduce intensities of pixels around centers. We archive the procedure by two algorithms of C-mean and subtractive clustering, and compare the results of the two algorithms. By using proper clustering algorithm, the intensity profile of data page will be uniform and the better data storage system can be realized.

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Comparison of time series clustering methods and application to power consumption pattern clustering

  • Kim, Jaehwi;Kim, Jaehee
    • Communications for Statistical Applications and Methods
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    • 제27권6호
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    • pp.589-602
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    • 2020
  • The development of smart grids has enabled the easy collection of a large amount of power data. There are some common patterns that make it useful to cluster power consumption patterns when analyzing s power big data. In this paper, clustering analysis is based on distance functions for time series and clustering algorithms to discover patterns for power consumption data. In clustering, we use 10 distance measures to find the clusters that consider the characteristics of time series data. A simulation study is done to compare the distance measures for clustering. Cluster validity measures are also calculated and compared such as error rate, similarity index, Dunn index and silhouette values. Real power consumption data are used for clustering, with five distance measures whose performances are better than others in the simulation.

K-means Clustering using Grid-based Representatives

  • Park, Hee-Chang;Lee, Sun-Myung
    • Journal of the Korean Data and Information Science Society
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    • 제16권4호
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    • pp.759-768
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    • 2005
  • K-means clustering has been widely used in many applications, such that pattern analysis, data analysis, market research and so on. It can identify dense and sparse regions among data attributes or object attributes. But k-means algorithm requires many hours to get k clusters, because it is more primitive and explorative. In this paper we propose a new method of k-means clustering using the grid-based representative value(arithmetic and trimmed mean) for sample. It is more fast than any traditional clustering method and maintains its accuracy.

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데이터 마이닝에서 그룹 세분화를 위한 2단계 계층적 글러스터링 알고리듬 (Two Phase Hierarchical Clustering Algorithm for Group Formation in Data Mining)

  • 황인수
    • 경영과학
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    • 제19권1호
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    • pp.189-196
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    • 2002
  • Data clustering is often one of the first steps in data mining analysis. It Identifies groups of related objects that can be used as a starling point for exploring further relationships. This technique supports the development of population segmentation models, such as demographic-based customer segmentation. This paper Purpose to present the development of two phase hierarchical clustering algorithm for group formation. Applications of the algorithm for product-customer group formation in customer relationahip management are also discussed. As a result of computer simulations, suggested algorithm outperforms single link method and k-means clustering.

A Study on a Statistical Matching Method Using Clustering for Data Enrichment

  • Kim Soon Y.;Lee Ki H.;Chung Sung S.
    • Communications for Statistical Applications and Methods
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    • 제12권2호
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    • pp.509-520
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    • 2005
  • Data fusion is defined as the process of combining data and information from different sources for the effectiveness of the usage of useful information contents. In this paper, we propose a data fusion algorithm using k-means clustering method for data enrichment to improve data quality in knowledge discovery in database(KDD) process. An empirical study was conducted to compare the proposed data fusion technique with the existing techniques and shows that the newly proposed clustering data fusion technique has low MSE in continuous fusion variables.

A Stigmergy-and-Neighborhood Based Ant Algorithm for Clustering Data

  • Lee, Hee-Sang;Shim, Gyu-Seok
    • Management Science and Financial Engineering
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    • 제15권1호
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    • pp.81-96
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    • 2009
  • Data mining, specially clustering is one of exciting research areas for ant based algorithms. Ant clustering algorithm, however, has many difficulties for resolving practical situations in clustering. We propose a new grid-based ant colony algorithm for clustering of data. The previous ant based clustering algorithms usually tried to find the clusters during picking up or dropping down process of the items of ants using some stigmergy information. In our ant clustering algorithm we try to make the ants reflect neighborhood information within the storage nests. We use two ant classes, search ants and labor ants. In the initial step of the proposed algorithm, the search ants try to guide the characteristics of the storage nests. Then the labor ants try to classify the items using the guide in-formation that has set by the search ants and the stigmergy information that has set by other labor ants. In this procedure the clustering decision of ants is quickly guided and keeping out of from the stagnated process. We experimented and compared our algorithm with other known algorithms for the known and statistically-made data. From these experiments we prove that the suggested ant mining algorithm found the clusters quickly and effectively comparing with a known ant clustering algorithm.

대용량 데이터 처리를 위한 하이브리드형 클러스터링 기법 (A Hybrid Clustering Technique for Processing Large Data)

  • 김만선;이상용
    • 정보처리학회논문지B
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    • 제10B권1호
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    • pp.33-40
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    • 2003
  • 데이터 마이닝은 지식발견 과정에서 중요한 역할을 수행하며, 여러 데이터 마이닝의 알고리즘들은 특정의 목적을 위하여 선택될 수 있다. 대부분의 전통적인 계층적 클러스터링 방법은 적은 양의 데이터 집합을 처리하는데 적합하여 제한된 리소스와 부족한 효율성으로 인하여 대용량의 데이터 집합을 다루기가 곤란하다. 본 연구에서는 대용량의 데이터에 적용되어 알려지지 않은 패턴을 발견할 수 있는 하이브리드형 신경망 클러스터링 기법의 PPC(Pre-Post Clustrering) 기법을 제안한다. PPC 기법은 인공지능적 방법인 자기조직화지도(SOM)와 통계적 방법인 계층적 클러스터링을 결합하여 두 과정에서는 군집의 내부적 특징을 나타내는 응집거리와 군집간의 외부적 거리를 나타내는 인접거리에 따라 유사도를 측정한다. 최종적으로 PPC 기법은 측정된 유사도를 이용하여 대용량 데이터 집합을 군집화한다. PPC 기법은 UCI Repository 데이터를 이용하여 실험해 본 결과, 다른 클러스터링 기법들 보다 우수한 응집도를 보였다.

범주형 값들이 순서를 가지고 있는 데이터들의 클러스터링 기법 (Clustering Algorithm for Sequences of Categorical Values)

  • 오승준;김재련
    • 산업경영시스템학회지
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    • 제26권1호
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    • pp.17-21
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    • 2003
  • We study clustering algorithm for sequences of categorical values. Clustering is a data mining problem that has received significant attention by the database community. Traditional clustering algorithms deal with numerical or categorical data points. However, there exist many important databases that store categorical data sequences. In this paper, we introduce new similarity measure and develop a hierarchical clustering algorithm. An experimental section shows performance of the proposed approach.

Enhanced Locality Sensitive Clustering in High Dimensional Space

  • Chen, Gang;Gao, Hao-Lin;Li, Bi-Cheng;Hu, Guo-En
    • Transactions on Electrical and Electronic Materials
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    • 제15권3호
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    • pp.125-129
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    • 2014
  • A dataset can be clustered by merging the bucket indices that come from the random projection of locality sensitive hashing functions. It should be noted that for this to work the merging interval must be calculated first. To improve the feasibility of large scale data clustering in high dimensional space we propose an enhanced Locality Sensitive Hashing Clustering Method. Firstly, multiple hashing functions are generated. Secondly, data points are projected to bucket indices. Thirdly, bucket indices are clustered to get class labels. Experimental results showed that on synthetic datasets this method achieves high accuracy at much improved cluster speeds. These attributes make it well suited to clustering data in high dimensional space.