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Yoshiharu Sato

Bio: Yoshiharu Sato is an academic researcher from Hokkaido University. The author has contributed to research in topics: Fuzzy clustering & Correlation clustering. The author has an hindex of 3, co-authored 8 publications receiving 139 citations.

Papers
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Book
01 Jan 1997
TL;DR: The general Fuzzy Clustering Model Using Aggregation Operators for Asymmetric Similarity and its application in 3-way data is described.
Abstract: Contents: Introduction to Fuzzy Clustering.- Fuzzy Clustering for 3-way Data.- Additive Clustering Models.- General Fuzzy Clustering Model Using Aggregation Operators.- Fuzzy Clustering for Asymmetric Similarity.

124 citations

Book ChapterDOI
01 Jan 1998
TL;DR: This paper presents a dynamic clustering model in which clusters are constructed in order to find the features of the dynamical change.
Abstract: This paper presents a dynamic clustering model in which clusters are constructed in order to find the features of the dynamical change.

5 citations

Journal ArticleDOI
TL;DR: The validity of this model is shown both by investigating the features of the asymmetric aggregation operators and through numerical applications.

5 citations

Proceedings ArticleDOI
21 Apr 1998
TL;DR: This paper presents a clustering model which analyzes asymmetric similarity data through several times and shows that the proposed method can capture the properties of time difference and asymmetry between two objects in spite of the numbering of the clusters.
Abstract: This paper presents a clustering model which analyzes asymmetric similarity data through several times. In general, proximity data (for example, mobility data, input-output data, perceptual confusion data, etc.) are observed in an asymmetric form. If such data are obtained over several times, then 3-way data are constructed. In this paper, we focus on the clustering techniques for 3-way data and show that the proposed method can capture the properties of time difference and asymmetry between two objects in spite of the numbering of the clusters.

2 citations

Book ChapterDOI
01 Jan 1998
TL;DR: The aggregation operator is introduced in the model to represent the degree of simultaneous belongingness of the objects to each cluster to generalize the model for an asymmetric similarity data.
Abstract: ADCLUS (ADditive CLUStering) is known as a clustering model which is designated for the purpose of finding the structure of the similarity data. The aim of this paper is to generalize this model from several points of view. The fast point of view is to extend the degree of belongingness of the objects to the continuous value in the interval [0,1], namely to an additive fuzzy clustering model, because the combinatorial optimization is inevitable in the algorithm for ADCLUS. The second point of view is to generalize the model for an asymmetric similarity data. And the third point of view is that we introduce the aggregation operator in the model to represent the degree of simultaneous belongingness of the objects to each cluster.

2 citations


Cited by
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Proceedings ArticleDOI
18 Dec 2006
TL;DR: This work studies various pruning methods to avoid expensive expected distance calculation in the UK-means algorithm, which is based on the traditional K-mean algorithm.
Abstract: We study the problem of clustering data objects whose locations are uncertain. A data object is represented by an uncertainty region over which a probability density function (pdf) is defined. One method to cluster uncertain objects of this sort is to apply the UK-means algorithm, which is based on the traditional K-means algorithm. In UK-means, an object is assigned to the cluster whose representative has the smallest expected distance to the object. For arbitrary pdf, calculating the expected distance between an object and a cluster representative requires expensive integration computation. We study various pruning methods to avoid such expensive expected distance calculation.

260 citations

Journal ArticleDOI
01 Feb 2004
TL;DR: A notion of credal partition is introduced, which subsumes those of hard, fuzzy, and possibilistic partitions, allowing to gain deeper insight into the structure of the data.
Abstract: A new relational clustering method is introduced, based on the Dempster-Shafer theory of belief functions (or evidence theory). Given a matrix of dissimilarities between n objects, this method, referred to as evidential clustering (EVCLUS), assigns a basic belief assignment (or mass function) to each object in such a way that the degree of conflict between the masses given to any two objects reflects their dissimilarity. A notion of credal partition is introduced, which subsumes those of hard, fuzzy, and possibilistic partitions, allowing to gain deeper insight into the structure of the data. Experiments with several sets of real data demonstrate the good performances of the proposed method as compared with several state-of-the-art relational clustering techniques.

244 citations

Journal ArticleDOI
TL;DR: In this paper, Derudder et al. used fuzzy classification analysis to define 22 urban arenas with their core and hybrid memberships, which are constituted by interweaving hierarchical and regional processes.
Abstract: DERUDDER B., TAYLOR P. J., WITLOX F. and C ATALANO G. (2003) Hierarchical tendencies and regional patterns in the world city network: a global urban analysis of 234 cities, Reg. Studies 37, 875–886. Previous explorations of the world city network have tended to focus on analyses of its upper ranks. Using a database on the global strategies of 100 financial and business firms across 234 cities, fuzzy classification analysis is used to define 22 urban arenas. With their " core' and "hybrid' memberships, these arenas are constituted by interweaving hierarchical and regional processes. The results include evaluations of the previously unassessed outer reaches of the world city network.D ERUDDER B., TAYLOR P. J., WITLOX F. et CATALANO G. (2003) Les tendances hierarchiques et les structures regionales du reseau de villes de taille mondiale: une analyse urbano-mondiale de 234 grandes villes, Reg. Studies 37, 875–886. Des etudes anterieures du reseau de villes de taille mondiale ont eu tendance a porter sur une a...

232 citations

01 Jan 1998

199 citations