Information search system and information search method using index

A method executed by a computing device for creating an index for conducting a search on a database based on a resource including a text sentence, the method comprising, under control of a processor of the computing device:

• loading a dictionary including a plurality of phrases associated with each other for each specific concept into a memory accessed by the processor;
• receiving an input of the resource via an input interface unit;
• performing text-processing for extracting a plurality of words, as tokens, from the text sentence in the received resource;
• generating a directed graph representing a connection relationship between the extracted plurality of tokens in accordance with the text sentence in order to expand the directed graph in a memory accessed by the processor;
• searching the directed graph with reference to the dictionary based on a search-target-phrase;
• and
• creating an index indicating the association with the resource based on the plurality of tokens in the directed graph in order to register the index in the database,
• wherein the searching the directed graph includes:
• setting at least one token in the directed graph to be the search-target-phrase;
• referring to the dictionary based on the set search-target-phrase;
• and
• if the search-target-phrase is found in the dictionary, locating a location in the directed graph where the search-target-phrase appeared, and
• wherein the generation of the directed graph includes:
• adding to the directed graph a new token that is based on at least one phrase associated with the search-target-phrase found in the dictionary in order to update the directed graph.

An information search method executed by a search apparatus including a search engine, the method comprising, under control of a processor of the search apparatus:

• conducting a search on an index in a database of the search apparatus based on a search query received from a client computer index in order to identify at least one resource from a resource information file based on the result of the search;
• expanding a directed graph being obtained from the identified at least one resource and including a predetermined related phrase that is related to a phrase in the at least one resource in a memory accessed by the processor and identifying, based on the directed graph expanded in the memory, a ground phrase that served as grounds for the at least one resource to be identified and an original phrase, in the at least one resource, that is associated with the ground phrase;
• and
• outputting information, as a search result, indicating the at least one resource, the ground phrase and the original phrase in order to transmit the search result to the client computer.

A recording medium having recorded thereon, in a non-transitory manner, a computer-readable program for causing a computing device to implement a method for creating an index for conducting a search on a database based on a resource including a text sentence, the method comprising:

• loading a dictionary including a plurality of phrases associated with each other for each specific concept in a memory accessed by the processor of the apparatus;
• receiving an input of the resource via an input interface unit;
• performing text-processing for extracting a plurality of words, as tokens, from the text sentence in the received resource;
• generating a directed graph representing a connection relationship between the extracted plurality of tokens in accordance with the text sentence;
• conducting a search on the directed graph with reference to the dictionary based on a search-target-phrase;
• and
• creating an index indicating the association with the resource based on the plurality of tokens in the directed graph,
• wherein the conducting the search on the directed graph includes:
• setting at least one token in the directed graph to be the search-target-phrase;
• referring to the dictionary based on the set search-target-phrase;
• and
• if the search-target-phrase is found in the dictionary, locating a location in the directed graph where the search-target-phrase appeared, and
• wherein the generating the directed graph includes:
• adding to the directed graph a new token that is based on at least one phrase associated with the search-target-phrase found in the dictionary in order to update the directed graph.