Hitachi, Ltd.

Tadataka Matsubayashi

Katsumi Tada

Natsuko Sugaya

Yasuhiko Inaba

Takuya Okamoto

Akihiko Yamaguchi

Mikihiko Tokunaga

Yasushi Kawashimo

Yousuke Ushiroji

Yoshifumi Sato

Shinya Yamamoto

Yuichi Ogawa

Katsushi Yako

Michio Iijima

Jugo Noda

Nobuo Kawamura

Norihiro Hara

Kazutomo Ushijima

Takaaki Yayoi

Kentaro Chigusa

Masaki Yotsutani

Yuuki Watanabe

Kazunari Sugiyama

Yasufumi Sato

Tsuyoshi Sudou

Shin′ Ya Yamamoto

Masayuki Hamakawa

Tsuyoshi Sudo

A retrieval apparatusfor searching document data comprises a document storage areafor storing documents to be searched and a document management tablefor storing a data size of a document such that the data size is associated with a document ID for identifying the document. The retrieval apparatusreads out from the document management table data sizes of documents to be searched, and calculates a retrieval document size by adding up the read out data sizes, and calculates an estimated time ttaken for a retrieval process by the index scan method and an estimated time ttaken for the retrieval process by the text scan method, based on the retrieval document size. The retrieval apparatuscompares the estimated times tand t, and decides which method to use for a retrieval process, the index scan method or the text scan method.

Retrieval apparatus, retrieval method and retrieval program

In registering operation of a document to be searched for, a document identifier management table for managing a range of a document identifier stored for each page and a page identifier of the page is created, and an individual-search-server's search range management table for managing the range of the document identifier in charge of each search server is created. In searching operation of each search server of the document to be searched for, the individual-search-server's search range management table is referred to acquire a range of the allocated document identifier. For each index key forming a query term specified as a query condition, the document identifier management table is referred to to acquire the page identifier storing the document identifier of the allocated range. The searching operation is carried out by referring to a page shown by the acquired page identifier.

System and method to enable parallel text search using in-charge index ranges

The present invention realize a high speed retrieval performance in a document retrieval system referring to partial data of documents including structured data such as XML documents and electric mails, without providing further memory. The present invention includes storage means for storing documents to be retrieved onto a disk device, a calculation means for calculating an allocated capacity of the memory, and storage means for saving, onto the memory, partial data of the documents stored on the disk device by the calculated allocated capacity of the memory. The present invention also includes a first retrieval means for retrieving partial data stored on the memory, determining means for determining whether or not to retrieve the documents stored on the disk device based on the result from the first retrieval, and a second means for retrieving the documents stored on the disk device based on the result from the above determination.

Method, program and apparatus for document retrieval system

The technology for changing the nodes in an information retrieving system using a computer. When information items are registered by allocating to n nodes, steps are used to extract index information as a set of pairs of index keys of information items and addresses of information items, divide the index information into m (m&#x3e;n) buckets and produce a partial inverted file to be closed within each of the buckets. Here, m and n are respectively integers of 1 (one) or above. When the allocation of the search-targeted ranges to the nodes is altered, the allocation to the buckets to each of the nodes is changed, and the partial inverted file of each bucket and the inverted file of the existing indexes are merged to produce new indexes, so that the indexes can be produced and updated with high speed.

Information retrieving system

Information that individual elements (characteristic character strings) indicative of characteristics of a registered document appear in the registered document is stored in advance. When calculating similarity of the registered document, a query designated by a searcher is analyzed. The query is represented by a characteristic vector having the individual elements which take the relation between a plurality of words into consideration. Pieces of appearance information of the individual words contained in the query are counted. The counted appearance information is compared with a searching index to calculate similarity between documents.

Method and apparatus for calculating similarity among documents

Retrieval conditions inputted from a plurality of users are registered. According to the retrieval conditions, a retrieval is conducted for a text inputted. As a result of the retrieval, similarity of the text is calculated for each retrieval condition. The text is delivered to users of which the retrieval condition satisfies the similarity.

Method of and an apparatus for retrieving and delivering documents and a recording media on which a program for retrieving and delivering documents are stored

Similar document retrieving method and system for retrieving similar documents from a document database storing plural documents written in different languages with high accuracy while suppressing retrieval noise even when difference is found in the number of registered documents in dependence on the species of description languages. Statistical information concerning the registration-subjected documents is collected on a language-by-language basis upon registration thereof. Upon retrieval of documents similar to a query document, weights of words extracted from the query document are taken into account and on a language-by-language basis by referencing the statistical information.

Method of searching similar document, system for performing the same and program for processing the same

A method for retrieving information from a computer system including a user terminal and a storage area, includes retrieving first information from the storage area using a first search query, the first search query having a first element and a first weight that is associated with the first element. The first search query has been formulated to retrieve target information. The first information includes at least a first data block. Second information is retrieved from the storage area using a second search query. The second search query has the first element, and a second weight that is associated with the first element. The second search query is derived from a relevance feedback provided on the first data block of the first information. An end-search criterion is provided to the user terminal. The end-search criterion provides information as to whether or not to end a first retrieval procedure for the target information. The first retrieval procedure being associated with a search query set, the search query set including a plurality of search queries, each having the first element.

Similarity-based search method by relevance feedback

In document retrieval having the relevance feedback function to modify a searching profile for retrieval on the basis of a user's evaluation to evaluate a search result as pertinent or impertinent, recommencement of the relevance feedback returned to a desired time is permitted. An evaluation inputted by a user, a searching profile modified by the evaluation and a search result based on the searching profile are all saved while making the correspondence between them. When a request for restoration of searching profile is made, a searching profile corresponding to an evaluation designated by the user is restored.

Method and system for retrieving a document and computer readable storage medium

Word boundary identification operations such as morpheme analysis is performed on documents to be registered, and the top positions and the end positions of words are identified. Word boundary information is obtained based on these identification results. Search indexes are created for sub-strings of a predetermined length (n-grams) extracted from the document being registered. The search index includes document identification information as well as occurrence position information which indicates that the string is located at the n-th position from the beginning of the text data, and word boundary information for an n-gram in a document.

Document retrieval method and document retrieval system

A document retrieval method using a computer program includes retrieving a first set of documents using a first query expression generated by the computer program. The first set of documents is provided to a user. An evaluation of the first set of documents is received from the user. The first query expression is changed to a second query expression generated by the computer program based on the evaluation.

Document retrieval method and system and computer readable storage medium

A registration/search method for structured documents where correspondence data is prepared between a fixed-length-string and a string occurrence position within a structured document for all fixed-length-strings in the document and for each structured document. A list of a character and all hierarchical elements containing the character and element lengths is prepared. An occurrence frequency and an occurrence position of a search term is obtained using the plurality of fixed-length-substrings and the occurrence frequency extracting index. A search character is selected from the search term. A hierarchical element containing the search character is obtained using the character from the element length index. A length of the element corresponding to a search range is extracted using the obtained occurrence position. A matching degree for the search term is calculated from the obtained occurrence frequency of the search term and the extracted element length of the element corresponding to the search range.

Registration method and search method for structured documents

A text mining method whereby documents (texts) can be analyzed from a wide variety of visual points. The text mining method includes: distinctive word and/or phrase extraction step of extracting words and/or phrases characteristically emerging in a processing subject document set obtained by taking out whole or a part of a set of documents registered beforehand; definition information setting step of setting definition information including a specified word or phrase or specified bibliography information; coincident word and/or phrase acquisition step of acquiring coincident words and/or phrases coincident in a predetermined range with a word or phrase or bibliography information included in said definition information from among words and/or phrases extracted at said distinctive word and/or phrase extraction step; and multiplex coincident word and/or phrase acquisition step of acquiring coincident words and/or phrases coincident in a predetermined range with an individual word or phrase or bibliography information acquired from each of a plurality of different definition information pieces.

Text mining method and apparatus allowing a user to analyze contents of a document set from plural analysis axes

In a text mining technique, if the system only extracts characteristic words and phrases frequently cooccurring with the respective components of an analysis axis as an analysis condition, similar words and phrases are extracted for any component. To clearly indicate existence of characteristic words and phrases which do not appear as cooccurrence words and phrases for other components of the analysis axis, it is desired to appropriately present distinguishable features between the components to the user. For this purpose, the frequency of appearances of a plurality of characteristic words and phrases in a document satisfying each analysis condition is calculated. As a result, multiple cooccurrence words and phrases and component-cooccurrence words and phrases are discriminatively displayed. It is therefore possible for the user to appropriately analyze the contents of a plurality of documents.

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Yokohama, Japan

Tadataka Matsubayashi