System and method for mining of temporal data

• US 7,644,078 B2
• Filed: 02/28/2005
• Issued: 01/05/2010
• Est. Priority Date: 02/28/2005
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Laxman, Srivatsan, Unnikrishnan, Kootaala P., Sastry, Pidaparthy S.
• Primary Examiner(s): Le; Miranda
• Application Number:
  US11/068,498
• Publication Number:
  US 20060195444A1
• Time in Patent Office: 1,772 Days
• Field of Search: 707 1- 10, 707100-102, 707/104.1, 707200-201, 706/58
• US Class Current: 706/20
• CPC Class Codes: G06F 16/2465 Query processing support for facilitating data mining operations in structured databases
• CPC Class Codes: G06F 16/2474 Sequence data queries, e.g. querying versioned data

Abstract

A system for temporal data mining includes a computer readable medium having an application configured to receive at an input module a temporal data series having events with start times and end times, a set of allowed dwelling times and a threshold frequency. The system is further configured to identify, using a candidate identification and tracking module, one or more occurrences in the temporal data series of a candidate episode and increment a count for each identified occurrence. The system is also configured to produce at an output module an output for those episodes whose count of occurrences results in a frequency exceeding the threshold frequency.

Claims

1. A computer-readable storage medium tangibly embodying executable instructions for:

receiving as input a temporal data series comprising events with start times and end times, a set of allowed dwelling times, a threshold frequency of occurrence, and an expiry time, wherein the expiry time provides a criterion for occurrence of an episode;

finding all frequent principal episodes of a particular length in the temporal data series having dwelling times, as determined by the start and end times, within the allowed dwelling times;

in successive passes through the temporal data series;

incrementing the particular length to generate an increased length;

combining frequent principal episodes to create combined episodes of the increased length;

creating a set of candidate episodes from the combined episodes by removing combined episodes which have non-frequent sub-episodes;

identifying one or more occurrences of a candidate episode in the temporal data series, wherein the identifying comprises tracking, with a plurality of automata, whether an occurrence of a candidate episode occurs in the temporal data series;

generating the plurality of automata configured to track whether an occurrence of a candidate episode occurs in the temporal data series, wherein the plurality of automata are configured to track a non-overlapping occurrence of a candidate episode;

incrementing a count for each identified occurrence;

determining frequent principal episodes of the increased length;

setting the particular length to the increased length; and

producing an output for frequent principal episodes, wherein a frequent principal episode is a principal episode whose count of occurrences results in a frequency meeting or exceeding the threshold frequency of occurrence.

2. The computer-readable storage medium of claim 1, wherein the identifying comprises identifying whether a non-interleaved occurrence of a candidate episode occurs in the temporal data series.

3. The computer-readable storage medium of claim 1, wherein the plurality of automata are configured to track a non-interleaved occurrence of a candidate episode.

4. A system for temporal data mining, comprising:

a computer readable storage medium that includes an application configured to;

receive at an input module a temporal data series comprising events with start times and end times, a set of allowed dwelling times, and a threshold frequency of occurrence, wherein the input module receives an expiry time for providing a criterion for occurrence of an episode;

identify using a candidate identification and tracking module one or more occurrences in the temporal data series of a candidate episode having dwelling times, as determined by the start and end times, within the allowed dwelling times,

in successive passes through the temporal data series;

increment the particular length to generate an increased length;

combine frequent principal episodes to create combined episodes of the increased length;

create a set of candidate episodes from the combined episodes by removing combined episodes which have non-frequent sub-episodes;

identifying one or more occurrences of a candidate episode in the temporal data series, wherein the identifying comprises tracking, with a plurality of automata, whether an occurrence of a candidate episode occurs in the temporal data series;

generate using an automata generation module the plurality of automata configured to track whether an occurrence of a candidate episode occurs in the temporal data series, wherein the plurality of automata are configured to track a non-overlapping occurrence of a candidate episode and;

increment a count for each identified occurrence;

determine frequent principal episodes of the increased length;

set the particular length to the increased length; and

produce at an output module an output for those episodes which are principal and whose count of occurrences results in a frequency meeting or exceeding the threshold frequency of occurrence.

5. The system of claim 4, wherein the candidate identification and tracking module identifies whether a non-interleaved occurrence of a candidate episode occurs in the temporal data series.

6. The system of claim 4, wherein the plurality of automata are adapted configured to track a non-interleaved occurrence of a candidate episode.

7. An apparatus for temporal data mining, comprising:

a processor for executing instructions;

a memory device including instructions comprising;

input instructions for receiving a temporal data series comprising events with start times and end times, a set of allowed dwelling times, a threshold frequency of occurrence, and an expiry time, wherein the expiry time provides a criterion for occurrence of an episode;

candidate identification and tracking instructions for identifying one or more occurrences in the temporal data series of a candidate episode having dwelling times, as determined by the start and end times, within the allowed dwelling times,

in successive passes through the temporal data series;

increment the particular length to generate an increased length;

combine frequent principal episodes to create combined episodes of the increased length;

create a set of candidate episodes from the combined episodes by removing combined episodes which have non-frequent sub-episodes;

identify one or more occurrences of a candidate episode in the temporal data series, wherein the identifying comprises tracking, with a plurality of automata, whether an occurrence of a candidate episode occurs in the temporal data series;

instructions for generating a plurality of automata configured to track whether an occurrence of a candidate episode occurs in the temporal data series, wherein the plurality of automata are configured to track a non-overlapping occurrence of a candidate episode;

increment a count for each identified occurrence;

determine frequent principal episodes of the increased length;

set the particular length to the increased length; and

output instructions for producing an output for those episodes which are principal and whose count of occurrences results in a frequency meeting or exceeding the threshold frequency of occurrence.

8. The apparatus of claim 7, wherein the candidate identification and tracking instructions comprise instructions for identifying whether a non-interleaved occurrence of a candidate episode occurs in the temporal data series.

9. The apparatus of claim 7, wherein the plurality of automata are adapted to track a non-interleaved occurrence of a candidate episode.