Anomaly recognition method for data streams
First Claim
1. A computer implemented method of recognizing anomalies in acoustic data representative of an analog waveform, the analog waveform varying in value as a function of time and having a plurality of cycles, the acoustic data comprising a one-dimensional ordered sequence of data elements, each element being representative of a respective analog value, the method comprising:
- using at least one computer with accessible input/output and at least one data store to perform the following steps;
(i) selecting a test group of test elements from the acoustic data;
(ii) selecting a comparison group of comparison elements from the acoustic data;
(iii) performing a comparison between the analog values of the test group and the analog values of the comparison group, the comparison involving the test elements of the test group on the one hand and the comparison elements of the comparison group on the other hand;
(iv) determining as a result of the comparison whether there is a match or a mismatch between the analog values of the test group and the analog values of the comparison group;
(v) repeating steps (ii), (iii), and (iv), incrementing the value of a mismatch counter each time a mismatch is found;
(vi) determining an anomaly measure representative of the anomaly of one or more of the test elements, the anomaly measure being dependent on mismatch counter value and being produced in said at least one data store.
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Accused Products
Abstract
This invention identifies anomalies in a data stream, without prior training, by measuring the difficulty in finding similarities between neighborhoods in the ordered sequence of elements. Data elements in an area that is similar to much of the rest of the scene score low mismatches. On the other hand a region that possesses many dissimilarities with other parts of the ordered sequence will attract a high score of mismatches. The invention makes use of a trial and error process to find dissimilarities between parts of the data stream and does not require prior knowledge of the nature of the anomalies that may be present. The method avoids the use of processing dependencies between data elements and is capable of a straightforward parallel implementation for each data element. The invention is of application in searching for anomalous patterns in data streams, which include audio signals, health screening and geographical data. A method of error correction is also described.
33 Citations
25 Claims
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1. A computer implemented method of recognizing anomalies in acoustic data representative of an analog waveform, the analog waveform varying in value as a function of time and having a plurality of cycles, the acoustic data comprising a one-dimensional ordered sequence of data elements, each element being representative of a respective analog value, the method comprising:
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using at least one computer with accessible input/output and at least one data store to perform the following steps; (i) selecting a test group of test elements from the acoustic data; (ii) selecting a comparison group of comparison elements from the acoustic data; (iii) performing a comparison between the analog values of the test group and the analog values of the comparison group, the comparison involving the test elements of the test group on the one hand and the comparison elements of the comparison group on the other hand; (iv) determining as a result of the comparison whether there is a match or a mismatch between the analog values of the test group and the analog values of the comparison group; (v) repeating steps (ii), (iii), and (iv), incrementing the value of a mismatch counter each time a mismatch is found; (vi) determining an anomaly measure representative of the anomaly of one or more of the test elements, the anomaly measure being dependent on mismatch counter value and being produced in said at least one data store. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A computer program product stored in a computer memory device, the computer program product being configured for, in use, recognizing anomalies in acoustic data representative of an analog waveform varying in value as a function of time and having a plurality of cycles, the acoustic data comprising a one-dimensional ordered sequence of data elements, each element being representative of a respective analog value, the computer program product having:
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computer-readable program means adopted for use with at least one computer with accessible input/output and at least one data store for; selecting a test group of test elements from the acoustic data; selecting a comparison group of comparison elements from the acoustic data; performing a comparison between the analog values of the test group and the analog values of the comparison group, the comparison involving the test elements of the test group on the one hand and the comparison elements of the comparison group on the other hand; determining as a result of the comparison whether there is a match or a mismatch between the analog values of the test group and the analog values of the comparison group; and determining an anomaly measure representative of the anomaly of one or more of the test elements, the anomaly measure being dependent on mismatch counter value and being produced in said at least one data store. - View Dependent Claims (23)
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24. A computer implemented apparatus for recognizing anomalies in acoustic data representative of an analog waveform varying in value as a function of time and having a plurality of cycles, the acoustic data comprising a one-dimensional ordered sequence of data elements, each element being representative of a respective analog value, the apparatus including:
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at least one computer accessible to input/output and at least one data store; means for selecting a test group of test elements from the acoustic data; means for selecting a comparison group of comparison elements from the acoustic data; means for performing a comparison between the analog values of the test group and the analog values of the comparison group, the comparison involving the test elements of the test group on the one hand and the comparison elements of the comparison group on the other hand; means for determining as a result of the comparison whether there is a match or a mismatch between the analog values of the test group and the analog values of the comparison group; and means for determining an anomaly measure representative of the anomaly of one or more of the test elements, the anomaly measure being dependent on mismatch counter value and being produced in said at least one data store. - View Dependent Claims (25)
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Specification