Event occurrence place estimation method, computer-readable recording medium storing event occurrence place estimation program, and event occurrence place estimation apparatus

A computer-readable hardware storage medium storing an event occurrence place estimation program for causing a computer to execute a process, the process comprising:

• acquiring a plurality of messages related to a disaster from social media to which the plurality of messages are posted;
• extracting a piece of occurrence place information indicating a plurality of occurrence places of the disaster from the acquired plurality of messages;
• specifying, among from the plurality of messages, a first message which includes information indicating that the first message is reposted in the social media;
• excluding the specified first message from the plurality of messages;
• after the excluding of the specified first message, ranking the occurrence places in descending order according to the number of messages corresponding to each of the occurrence places,
• cumulating, for each of the occurrence places, the number of messages associated with the respective occurrence places to acquire a cumulative composition ratio curve indicating a ratio of the number of messages associated with the respective occurrence places to all of the number of the messages;
• and
• detecting one or more locations effected by the disaster, the detecting including
• identifying, on the cumulative composition ratio curve, a change point where a change rate of the cumulative composition ratio curve becomes similar to an average increase ratio of the cumulative composition ratio curve;
• and
• outputting, on a displayed image, one or more first occurrence places ranked at or higher than the change point of the cumulative composition ratio curve with distinguishing one or more second occurrence places ranked lower than the change point to cause a user to recognize the one or more first occurrence places as the one or more locations effected by the disaster.

An event occurrence place estimation apparatus comprising:

• a hardware processor configured to
• acquire a plurality of messages related to a disaster from social media to which the plurality of messages are posted;
• extract a piece of occurrence place information indicating a plurality of occurrence places of the disaster from the acquired plurality of messages;
• specify, among from the plurality of messages, a first message which includes information indicating that the first message is reposted in the social media,
• exclude the specified first message from the plurality of messages,
• after the specified first message is excluded from the plurality of messages, rank the occurrence places in descending order according to the number of messages corresponding to each of the occurrence places,
• cumulate, the number of messages associated with the respective occurrence places to acquire a cumulative composition ratio curve indicating a ratio of the number of messages associated with the respective occurrence places to all of the number of the messages;
• and
• detect one or more locations effected by the disaster, including
• identify, on the cumulative composition ratio curve, a change point where a change rate of the cumulative composition ratio curve becomes similar to an average increase ratio of the cumulative composition ratio curve;
• and
• output, on a displayed image, one or more first occurrence places ranked at or higher than the change point of the cumulative composition ratio curve with distinguishing one or more second occurrence places ranked lower than the change point to cause a user to recognize the one or more first occurrence places as the one or more locations effected by the disaster.