Patent ID: 7225120
Filing Date: 2007-05-29
Classification: G06F

Abstract:
1. A method of extracting an important term from an input document including one or plural document segments, comprising the steps of: (a) generating, for the respective document segments, document segment vectors having values relating to occurrence frequencies of terms occurring in the document segments as component values; (b) generating a square sum matrix from the document segment vectors to calculate eigenvectors and eigenvalues of the square sum matrix; (c) selecting and outputting a definite number of eigenvectors and eigenvalues of the square sum matrix; (d) generating, with respect to the terms in the input document, term vectors in which only components corresponding to the terms included in the items have a first binary value and the other components have a second binary value; (e) obtaining a measure of the importance of the terms by using the definite number of eigenvectors, the definite number of eigenvalues, and the term vectors; (f) selecting and outputting the important term of the input document by using the importance; (g) the square sum matrix is calculated as; where: M=the number of the document segments, an m-th document segment vector is d T denotes transpose of a vector, and d