Patent ID: 7499923
Filing Date: 2009-03-03
Classification: G06F,G06K,Y10S

Abstract:
1. A computer implemented method of clustering documents, each clustering document having one or plural document segments in an input document, said method comprising steps: (a) obtaining a co-occurrence matrix for the input document by using a computer, the co-occurrence matrix is a matrix reflecting occurrence frequencies of terms and co-occurrence frequencies of term pairs, and obtaining an input document frequency matrix for a set of input documents based on occurrence frequencies of terms or term pairs appearing in the set of input documents wherein said step (a) further includes: generating an input document segment vector for each input document segment of said input document segments based on occurrence frequencies of terms appearing in said each input document segment; obtaining the co-occurrence matrix for the input document from input document segment vectors; and obtaining the input document frequency matrix from the co-occurrence matrix for each document; (b) selecting a seed document from a set of remaining documents that are not included in any cluster existing, and constructing a current cluster of an initial state based on the seed document, wherein said selecting and said constructing comprises: (c) making documents, which have document commonality to a current cluster higher than a threshold, belong temporarily to the current cluster; wherein said making comprising: (d) repeating step (c) until number of documents temporarily belonging to the current cluster does not increase; (e) repeating steps (b) through (d) until a given convergence condition is satisfied; and (f) deciding, on a basis of the document commonality of each document to each cluster, a cluster to which each document belongs and outputting said cluster.