Methods, systems, and apparatus for multi-purpose metering
View Patent ↗Methods and apparatus for multi-purpose metering are disclosed. An example method includes acquiring a rate of data transfer to/from the monitored location and comparing the acquired rate of data transfer to a threshold. The example method also includes setting at least one media monitoring device in a first bandwidth mode when the acquired rate of data transfer exceeds the threshold, and setting the at least one media monitoring device in a second bandwidth mode when the acquired rate of data transfer is below the threshold.
1. A method to match query signatures with reference signatures comprising:
applying a hash function to a plurality of reference signatures and to a plurality of query signatures, the hash function to identify reference index values in a hash table for each of the reference signatures and to identify query index values in the hash table for each of the query signatures;
selecting three adjacent subsets of the query signatures to form first, second and third segments;
calculating time offset values between matching sets of the reference index values and the query index values for each of the first, second and third segments; and
comparing an accumulated number of similar time offset values in the first, second and third segments to identify a first offset value that exceeds a threshold number of occurrences in each one of the segments.
2. A method as defined in claim 1 , wherein an index of the hash table comprises a first linked list, the first linked list comprising at least one of a null pointer, a first reference timestamp associated with a first reference signature, or a plurality of reference timestamps associated with the first reference signature.
3. A method as defined in claim 2 , further comprising advancing a pointer of the hash table to a second linked list when the null pointer is detected.
4. A system to match query signatures with reference signatures comprising:
a reference table comprising a plurality of reference signatures, each of the plurality of reference signatures associated with a reference timestamp;
a query table comprising a plurality of query signatures, each of the plurality of query signatures associated with a query timestamp;
a hash table to store the plurality of reference signatures and associated timestamps, the plurality of reference signatures indexed in the hash table based on a hash function;
a programmed hardware processor to calculate, for each of first, second and third groups of the query system, respective offsets between first and second timestamps, the first and second timestamps for each of the offsets associated with reference signatures and query signatures, respectively, having the same index values; and
a histogram to respectively accumulate first, second and third occurrences of offsets having similar values in the first, second and third segments, the processor to identify a match between the query signatures and the reference signatures having the same index when the accumulated occurrences exceed an occurrence threshold in each one of the first, second and third segments.
5. A system as defined in claim 4 , wherein the first, second and third segments are at least one of overlapping or non-overlapping.
6. A system as defined in claim 5 , wherein the non-overlapping first, second and third segments are temporally adjacent in the query table.
7. A system as defined in claim 4 , further comprising a plurality of linked-lists, each of the plurality of linked-lists associated with an index of the hash table.
8. A system as defined in claim 7 , wherein each of the plurality of linked-lists comprises a null pointer or at least one reference signature, the reference signature having an associated reference timestamp.
9. A system as defined in claim 8 , wherein each one of the reference signatures of the linked list corresponds to a portion of broadcast media.
10. A method as defined in claim 1 , wherein the first segment, the second segment and the third segment represent temporally adjacent query signatures.
11. A method as defined in claim 1 , further comprising using a threshold quantity of similar time offset values from the first, second and third segments to identify the query signatures that match the reference signatures.
12. A method as defined in claim 1 , wherein a portion of the query signatures of the second segment overlap with a portion of the query signatures of at least one of the first, second or third segments to eliminate false positive matches.
13. A method as defined in claim 1 , wherein the first offset value comprises a match between reference media and media detected by household monitoring equipment.
14. A tangible article of manufacture storing machine accessible instructions that, when executed, cause a machine to at least:
apply a hash function to a plurality of reference signatures and to a plurality of query signatures, the hash function to identify reference index values in a hash table for each of the reference signatures and to identify query index values in the hash table for each of the query signatures;
select three adjacent subsets of the query signatures to form first, second and third segments;
calculate time offset values between matching sets of the reference index values and the query index values for each of the first, second and third segments; and
compare an accumulated number of similar time offset values in the first, second and third segments to identify a first offset value that exceeds a threshold number of occurrences in each one of the segments.
15. A tangible article of manufacture as described in claim 14 further comprising instructions to generate an index of the hash table as a first linked list, the first linked list comprising at least one of a null pointer, a first reference timestamp associated with a first reference signature, or a plurality of reference timestamps associated with the first reference signature.
16. A tangible article of manufacture as described in claim 15 further comprising instructions to advance a pointer of the hash table to a second linked list when the null pointer is detected.