Matsushita Electric Industrial Co., Ltd.

Mitsuaki Inaba

Yuji Kanno

Naohiko Noguchi

Mitsuhiro Sato

Masako Nomoto

Hayashi Ito

Kenji Nagao

Hideki Yasukawa

Yoshio Fukushige

Kazuaki Kurachi

Yuichi Kobayakawa

A searching apparatus includes an index generation portion for generating an index to provide data of the number of documents including the key word and the number of appearances of the key word. Matching degrees between the key word and documents are calculated from the number of documents including the key word and the number of appearances of the key word. A portion of documents are arranged in order of the matching degree in a buffer which are outputted as the searching result. Lower rank documents regarding the matching degree are searched by comparing the lowest matching degree of the neighbour higher ranked document arranged in the buffer. At first time searching, data of the latest edition of the documents stored in a memory is detected and stored and is used to provide second time searching operation to eliminate inconsistency in the searching result between the editions at first and second time searching operations. The index is generated every field of each document. The matching degree of combined field is calculated by logical operation between the two fields. Moreover, an index of combined field may be generated and one of field of the combined field may be omitted. The matching degree of the other field is also obtained by another logical operation.

Document searching apparatus

A system for providing keywords to facilitate a search in a text retrieval system. For each of texts constituting a text base, the system creates a word ID of each of words used in the text and a word occurrence count of a corresponding word. The word occurrence count indicates a number of occurrences of a word in each text. For each of words used in any of the texts constituting the text base, the system creates a total word occurrence count and a containing text count indicative of the number of texts containing the word. For each of words contained in the selected texts, a degree of importance is calculated by using the word occurrence count, the total word occurrence count and the containing text count. The words contained in the selected texts are sorted in order of the degree of importance. At least a part of the sorted words are displayed as related keywords.

Keyword extracting system and text retrieval system using the same

A document retrieval system for searching a document coinciding with a retrieval request the user inputs and further ranking the document in accordance with the degree of coincidence between the document and the retrieval request. In the document retrieval system, a word frequency calculating section finds out the number of documents where a word appears, a frequency of occurrence of the word in a document and obtains a weighting parameter for the word, and a frequency score calculating section obtains a frequency score on the basis of the output of the word frequency calculating section. In addition, a word cooccurrence relation checking section checks word cooccurrence relations of the retrieval request and the document, and a cooccurrence score calculating section calculates a cooccurrence score from the degree of coincidence therebetween. A document score calculating section calculates a document score on the basis of the frequency score and the cooccurrence score. The documents are ranked in order of document score and displayed to the user.

Document retrieval system

A rigidity checking method and apparatus is presented. A composite feature vector is first generated by combining three pairs of coordinates obtained for a feature point of a target object from three pictures of the target object. A covariance matrix of the compound feature vector is calculated by finding a product of a variance matrix comprising a variance of each element of the compound feature vector and the transposed matrix of the variance matrix. The rigidity of the target object is calculated by using the element of the covariance matrix and compared with a predetermined threshold to determine whether the target object is a rigid body. Thus, a rigidity checking is directly achieved from the joint distribution of feature points in the three pictures without assuming the coefficients of a set of constraint equations.

Rigidity checking method and apparatus with the result freed from the

A new type of text search apparatus, capable of finding all occurrence positions of a search string that is an arbitrary character string, within a text which is written as a continous sequence of characters, utilizes for text position reference purposes in an index file, words which each occur (at least once within the text) as the maximum length word, referred to as an extension word, among a set of arbitrarily predefined dictionary words extending from a specific character position. Each such occurrence of a word as an extension word defines one of a set of text position elements, with that set covering all of the character positions of the text. The index file also includes a table which relates each of the extension words to the respective positions at which each of the partial character strings of the word occur within the word. Each occurrence of an arbitrary search string within the text can thereby be expressed as either a partial character string within a single text position element, or as a sequence of partial character strings within a set of sequentially occurring text position elements, so that all such occurrences can be found by utilizing the index file.

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Tokyo, Japan

Mitsuaki Inaba