FORENSIC SYSTEM, FORENSIC METHOD, AND FORENSIC PROGRAM

• US 20150088876A1
• Filed: 10/09/2013
• Published: 03/26/2015
• Est. Priority Date: 10/09/2012
• Status: Active Grant

• Current Assignee: Fronteo, Inc.
• Original Assignee: Ubic, Inc.
• Inventors: Morimoto, Masahiro, Shirai, Yoshikatsu, Takeda, Hideki, Hasuko, Kazumi
• Granted Patent: US 9,396,273 B2
• Time in Patent Office: Days
• US Class Current: 707/728
• CPC Class Codes: G06F 16/00 Information retrieval; Database structures therefor; File system structures therefor
• CPC Class Codes: G06F 16/24578 using ranking
• CPC Class Codes: G06F 16/334 Query execution G06F16/335 takes precedence
• CPC Class Codes: G06F 16/9535 Search customisation based on user profiles and personalisation
• CPC Class Codes: G06Q 10/10 Office automation; Time management
• CPC Class Codes: G06Q 50/18 Legal services

Abstract

A forensic system includes a result information receiving unit that receives result information which is a determination result of connection between a lawsuit and a document group including a predetermined number of documents, which is extracted from document data included in digital information, by a user, an element selection unit that calculates evaluation values of elements which commonly appear in the document group in each result information item from the characteristics of the elements and selects the elements on the basis of the evaluation values, a score calculation unit that calculates a score of each document in the document data from the selected elements included in each document of the document data and the evaluation values of the selected elements, and a recall ratio calculation unit that calculates a recall ratio related to the determination of the connection to the lawsuit on the basis of the score.

Claims

1. A forensic system that acquires digital information recorded in a plurality of computers or servers and analyzes connection of the acquired digital information to a lawsuit, comprising:

a result information receiving unit that receives result information which is a determination result of connection between the lawsuit and a document group including a predetermined number of documents, which is extracted from document data included in the digital information, by a user;

an element selection unit that calculates evaluation values of elements which commonly appear in the document group in each result information item from the characteristics of the elements and selects the elements on the basis of the evaluation values;

a score calculation unit that calculates a score of each document in the document data from the selected elements included in each document of the document data and the evaluation values of the selected elements; and

a recall ratio calculation unit that calculates a recall ratio related to the determination of the connection to the lawsuit on the basis of the score.

2. The forensic system according to claim 1,

wherein the element selection unit selects the elements on the basis of a sum of the evaluation values.

3. The forensic system according to claim 1,

wherein the element selection unit arranges the elements in a descending order of the evaluation values, extracts elements until a sum of the evaluation values of the elements reaches a unique target value, and selects the extracted elements.

4. The forensic system according to claim 1,

wherein the recall ratio calculation unit calculates the recall ratio from a percentage of documents of the document group with a predetermined score or more among the documents whose scores have been calculated.

5. The forensic system according to claim 1,

wherein the recall ratio calculation unit arranges documents whose scores have been calculated in the document data in descending order of the scores, extracts a predetermined percentage of documents in descending order of the scores, and calculates, as the recall ratio, a percentage of the document group in the extracted documents.

6. The forensic system according to claim 1,

wherein the element selection unit calculates the evaluation value on the basis of an amount of transmitted information of the element.

7. The forensic system according to claim 1, further comprising:

an automatic determination unit that determines a connection of a document, which has a score greater than a predetermined threshold value, to the lawsuit.

8. The forensic system according to claim 1, further comprising:

an extraction unit that extracts a document group including a predetermined number of documents from the document data included in the digital information; and

a display unit that displays the extracted document group on a screen.

9. The forensic system according to claim 3, further comprising:

an element re-selection unit that re-selects the elements using the sum of the evaluation values of the elements and a difference between the unique target value and the recall ratio when the recall ratio is less than the unique target value.

10. The forensic system according to claim 9,

wherein, when the recall ratio is less than the unique target value, the element re-selection unit extracts elements from a set of elements except for the elements, which have been extracted from the elements until the sum of the evaluation values of the elements reaches the difference between the unique target value and the recall ratio, until the recall ratio is greater than the unique target value, and selects the extracted elements.

11. The forensic system according to claim 9,

wherein, when the recall ratio is less than the unique target value, the score calculation unit further calculates a second score of each document in the document data, using the elements selected by the element re-selection unit and the evaluation values of the elements selected by the element re-selection unit, and composes the scores and the second scores to re-calculate the score of each document in the document data.

12. The forensic system according to claim 8,

wherein the extraction unit has a function of extracting the document group from the document data using random sampling.

13. A forensic method that acquires digital information recorded in a plurality of computers or servers, analyzes connection of the acquired digital information to a lawsuit, and causes a computer to perform:

a step of receiving result information which is a determination result of connection between the lawsuit and a document group including a predetermined number of documents, which is extracted from document data included in the digital information, by a user;

a step of calculating evaluation values of elements which commonly appear in the document group in each result information item from the characteristics of the elements and selecting the elements on the basis of the evaluation values;

a step of calculating a score of each document in the document data from the selected elements included in each document of the document data and the evaluation values of the selected elements; and

a step of calculating a recall ratio related to the determination of the connection to the lawsuit on the basis of the score.

14. A forensic program that acquires digital information recorded in a plurality of computers or servers, analyzes connection of the acquired digital information to a lawsuit, and causes a computer to implement:

a function of receiving result information which is a determination result of connection between the lawsuit and a document group including a predetermined number of documents, which is extracted from document data included in the digital information, by a user;

a function of calculating evaluation values of elements which commonly appear in the document group in each result information item from the characteristics of the elements and selecting the elements on the basis of the evaluation values;

a function of calculating a score of each document in the document data from the selected elements included in each document of the document data and the evaluation values of the selected elements; and

a function of calculating a recall ratio related to the determination of the connection to the lawsuit on the basis of the score.