Patents by Inventor Mitsuru Akizawa

Mitsuru Akizawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6094647
    Abstract: A method for making document information searches. In performing a document search with respect to the desired key word, two stages of presearch are carried out. In a first stage of presearch, a character component table in which an existence of character codes for every document is stated with respect to all the character codes contained in the group of document text data of stored documents is generated, and the character component table is searched for all the character strings constituting a desiredly designated search subject key word to thereby extract all the documents each containing all the character codes constituting the search subject key word. In a second stage of presearch, contracted text data for every document in which adjuncts and duplication of repeatedly stated words contained in advance in the text data are eliminated is generated, and the documents each containing the search subject key words by word are extracted from the documents extracted by the first presearch.
    Type: Grant
    Filed: April 11, 1997
    Date of Patent: July 25, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Kanji Kato, Hiromichi Fujisawa, Mitsuo Ooyama, Hisamitsu Kawaguchi, Atsushi Hatakeyama, Noriyuki Kaneoka, Mitsuru Akizawa, Masaaki Fujinawa, Hidefumi Masuzaki, Masaharu Murakami
  • Patent number: 5757983
    Abstract: A document retrieval method and system for retrieving, from a document database storing document data in the form of character codes, a document which contains given search terms and which meets a given search query condition. From documents loaded from the document database, a document containing terms which match the search terms is searched to generate document identification (ID) information including a document identifier of the searched document and containing match terms found to match with the search terms as well as term identifiers of the match terms and position information of the match terms in the searched document. A decision is then made as to whether or not the position information of the match terms satisfies a positional condition specified in the search query condition concerning a positional relation between the search terms, and match information is then generated indicating satisfaction of the search query condition when the positional condition is satisfied.
    Type: Grant
    Filed: August 21, 1995
    Date of Patent: May 26, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Hisamitsu Kawaguchi, Mitsuru Akizawa, Kanji Kato, Atsushi Hatakeyama, Hiromichi Fujisawa
  • Patent number: 5603003
    Abstract: In a computer system having an interface with an I/O bus given disconnect/reconnect functions and a plurality of magnetic disk subsystems connected with the I/O bus, control divides a file at a disk access time with reference to disk management information, file management information and file descriptor translation information to read/write a plurality of such files asynchronously. Thus, high speed file access can be realized by only the plurality of magnetic disk subsystems without requiring any special control hardware. A corresponding relation between subfiles in a virtual directory and the application request file can be taken to construct the directory, thus making the divided storage transparent to the application.
    Type: Grant
    Filed: March 1, 1993
    Date of Patent: February 11, 1997
    Assignees: Hitachi, Ltd., Hitachi Computer Engineering Co., Ltd.
    Inventors: Mitsuru Akizawa, Kanji Kato, Hiroyoshi Suzuki, Toshiyuki Maki, Hirofumi Yamashita, Akira Kito, Hidenori Yamada
  • Patent number: 5548724
    Abstract: A typical structure of a file server system is a file server system having a plurality of file servers connected in parallel on a network and sharing files placed distributedly in the file servers among a plurality of client computers, and there are provided in a specific file server among the plurality of file servers, a load information monitoring device for measuring respective loads of the plurality of file servers and a file access request distributing device for referring to the loads measured by the load information monitoring device so as to select a file server having a light load from the plurality of file servers having light loads, and distributing a file access request transmitted from client computers to the selected file server.
    Type: Grant
    Filed: March 21, 1994
    Date of Patent: August 20, 1996
    Assignees: Hitachi, Ltd., Hitachi Computer Engineering Co., Ltd.
    Inventors: Mitsuru Akizawa, Hirofumi Yamashita, Hisamitsu Kawaguchi, Katsumi Tada, Kanji Kato, Akira Kito, Hidenori Yamada
  • Patent number: 5519857
    Abstract: A method and apparatus for performing a document information search to uncover specified text data containing a given search subject key word from a group of document text data stored in a memory. In the document information search method, two stages of presearch are carried out to perform the document search with respect to a desired subject key word. In a first stage of presearch, a character component table is generated in which the existence of character codes for every document is set forth with respect to all the character codes contained in the group of document text data of stored documents. The character component table is searched for all the character codes comprising a designated search subject key word to thereby extract all documents containing all the character codes comprising the search subject key word. Further, in the presearch step, all texts without the possibility of containing the search subject key word are eliminated.
    Type: Grant
    Filed: November 30, 1992
    Date of Patent: May 21, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Kanji Kato, Hiromichi Fujisawa, Mitsuo Ooyama, Hisamitsu Kawaguchi, Atsushi Hatakeyama, Noriyuki Kaneoka, Mitsuru Akizawa, Masaaki Fujinawa, Hidefumi Masuzaki, Masaharu Murakami
  • Patent number: 5497488
    Abstract: A character string search arithmetic operation is performed at high speed with a small hardware scale processing module, such as a symbol string search module. The search module is connected to a CPU through address and data buses and includes a function definition section for defining a function of the apparatus in accordance with a command from the CPU, a data input/output section for receiving a symbol string to be searched through the data bus and for outputting the result of a search. A search processing section performs the search based on a function defined by the function definition section. A symbol string to be searched for, which is internally stored, is compared with the symbol string data input to the module's data input/output means. A condition holding section holds data indicative of an internal condition corresponding to the result of the search processing. Thereby, the CPU and the symbol string search module can perform the search at high speed.
    Type: Grant
    Filed: March 13, 1995
    Date of Patent: March 5, 1996
    Assignees: Hitachi, Ltd., Hitachi Maxell, Ltd.
    Inventors: Mitsuru Akizawa, Kouki Noguchi, Takehisa Hayashi, Kanji Kato, Hitoshi Matsushima
  • Patent number: 5452451
    Abstract: A parallel comparator for performing a parallel and high-speed processing for collation of partial character strings which are partially taken out of a plurality of character strings of interest to be searched out with a character string to be searched in which document data to be searched is arranged sequentially from a leading character, is provided in a front stage of an automaton executing device. Only when a part of the character string to be searched coincides with the partial character string set in the comparator, the collation of the remaining portion of the character string to be searched is performed by the automaton executing device. Also, it is possible to set "don't care" in which a character at any position in the partial character string is ignored at the time of comparison by the comparator and to set a negation condition in which the comparison by the comparator is made taking the negation of a character at any position in the partial character string.
    Type: Grant
    Filed: December 1, 1994
    Date of Patent: September 19, 1995
    Assignees: Hitachi, Ltd., Hitachi Maxell, Ltd.
    Inventors: Mitsuru Akizawa, Hisamitsu Kawaguchi, Kanji Kato, Atsushi Hatakeyama, Kouki Noguchi, Hiromichi Fujisawa
  • Patent number: 5398206
    Abstract: A semiconductor memory device includes signal lines, a decoder for decoding an inputted address to output the decoded result to some of the signal lines, a matrixed memory array, a part of which being pre-specified as a compensated area, read out means for reading out data from memory cells in an area specified in accordance with a decode signal on the some signal line, a detector for detecting that the address is related with the compensated area from the decode signal on the some signal lines, the compensated area being pre-related with the some signal lines, and a fixed data outputting circuit for merging predetermined data into a predetermined part of the data read out from the memory cells in accordance with the detection signal to output the merged data. The fixed data outputting circuit is controlled by a control circuit in response to a merge control signal to output the data read out from the memory cells without the merging operation.
    Type: Grant
    Filed: February 12, 1991
    Date of Patent: March 14, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Mitsuru Akizawa, Kazuhiko Iwasaki, Kouki Noguchi, Ryuuji Shibata, Noboru Yamaguchi
  • Patent number: 5168533
    Abstract: A method and apparatus for making document information search and a magnetic disk unit to be used for realizing the method and apparatus. In the document information search method, in performing document search with respect to a desired subject key word, two stages of presearch are carried out. In a first stage of presearch (step 402), a character component table (500) in which existence of character codes for every document is stated with respect to all the character codes contained in the group of document text data of stored documents is generated, and the character component table is searched for all the character codes constituting a desiredly designated search subject key word to thereby extract all the documents each containing all the character codes constituting the search subject key word.
    Type: Grant
    Filed: August 9, 1990
    Date of Patent: December 1, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Kanji Kato, Hiromichi Fujisawa, Mitsuo Ooyama, Hisamitsu Kawaguchi, Atsushi Hatakeyama, Noriyuki Kaneoka, Mitsuru Akizawa, Masaaki Fujinawa, Hidefumi Masuzaki, Masaharu Murakami
  • Patent number: 5138669
    Abstract: A range-conditional character string retrieving method and system capable of performing retrieval of a numerical value from a character string at an increased speed by shortening the time taken for generation of finite automaton, range condition retrieval for a character string containing admixedly numeric characters and non-numeric characters such as alphabetic letters and highly intelligent retrieval of a numerical value with designation of preceding and succeeding characters. Given range condition is partitioned in accordance with difference in the digit number between upper and lower limit values, whereon retrieval is performed in each of partitioned ranges in parallel. When a finite automaton transits from a predetermined state to at least two state in dependence on the result of collation of a character string subjected to retrieval, conditions for the state transitions are designated in terms of corresponding codes.
    Type: Grant
    Filed: July 1, 1991
    Date of Patent: August 11, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Takanori Shimura, Hisamitsu Kawaguchi, Kanji Kato, Atsushi Hatakeyama, Mitsuru Akizawa
  • Patent number: 5101376
    Abstract: In associative memory device, a search key is stored in the first storage element and a storage key is stored in the second storage elements, respectively via a first data bus. The search key is supplied to the comparator via a second data bus, and the storage key stored in the second storage element is supplied to the comparator. The comparator compares the search key with the storage key. When the storage key is consistent with the search key, the comparator delivers as the associative operation results a comparison consistency output signal to a priority encoder circuit which outputs code information having a limited bit length. This code information is transferred to CPU via a selector circuit. If the comparator delivers a comparison inconsistency output signal, this signal is directly passed to CPU via the priority encoder circuit, so that the contents of the first storage element is rewritten.
    Type: Grant
    Filed: April 23, 1991
    Date of Patent: March 31, 1992
    Assignees: Hitachi, Ltd., Hitachi Maxell Ltd.
    Inventors: Kouki Noguchi, Mitsuru Akizawa, Kanji Kato
  • Patent number: 5036486
    Abstract: In associative memory device, a search key is stored in the first storage element and a storage key is stored in the second storage elements, respectively via a first data bus. The search key is supplied to the comparator via a second data bus, and the storage key stored in the second storage element is supplied to the comparator. The comparator compares the search key with the storage key. When the storage key is consistent with the search key, the comparator delivers as the associative operation results a comparison consistency output signal to a priority encoder circuit which outputs code information having a limited bit length. This code information is transferred to CPU via a selector circuit. If the comparator delivers a comparison inconsistency output signal, this signal is directly passed to CPU via the priority encoder circuit, so that the contents of the first storage element is rewritten.
    Type: Grant
    Filed: July 9, 1990
    Date of Patent: July 30, 1991
    Assignees: Hitachi, Ltd, Hitachi Maxell, Ltd.
    Inventors: Kouki Noguchi, Mitsuru Akizawa, Kanji Kato