Information search method, apparatus, program and computer readable recording medium

摘要

An information search apparatus is provided. The information search apparatus includes: a character string input unit configured to obtain a character string from a client; a character string information search unit configured to obtain information that includes the character string from an index DB; a similarity calculation unit configured to calculate degree of similarity between the character string and searched information; and an output unit configured to output the searched information in descending order of the degree of similarity. In the information search apparatus, the character string information search unit includes a unit configured to, when the input character string contains a plurality of words, search an index DB, based on each word, that stores words and occurrence position information of the words to obtain a distance between occurrence positions of the words, and the similarity calculation unit includes a unit configured to calculate the degree of similarity based on the distance between occurrence positions of the words.

主权项

1. An information search apparatus comprising:
a processor; a memory that stores an index database (DB); a character string input unit configured to obtain a character string from a client; a character string information search unit configured to obtain information that includes the character string from the index DB; a similarity calculation unit, implemented by the processor, configured to calculate degree of similarity between the character string and searched information; and an output unit configured to output the searched information in descending order of the degree of similarity, wherein the index DB stores each word with sentence-based occurrence position information, of each document where the word occurs, that indicates each position of sentences where the word occurs, and when the input character string contains a plurality of words, the character string information search unit searches the index DB, based on each word, to obtain a document d including each word and occurrence positions of each word in the document d, and the similarity calculation unit calculates a degree of agreement score(Q,d,k) between occurrence positions of the words byscore(Q,d,k)⁢∑qi∈Q⁢⁢∑qj∈(Q-qi)⁢⁢1α⁢⁢k+1⁢count⁡(Posd⁡(qi),Posdk⁡(qj))so as to calculate the degree of similarity based on the degree of agreement score (Q,d,k),
wherein Q indicates a set of words obtained by dividing the character string, Posd (qi) indicates an occurrence position of a word qi in the document d, Posdk(qi) indicates a value obtained by subtracting k from an occurrence position of a word qi in the document d, k indicates a counter value, α indicates a coefficient, and Count (Pos,Pos) indicates a function for receiving two pieces of position data and returning a degree of agreement.