1. A method, comprising:
obtaining a first relevance ranking of a taxonomy item in a particular data file using a first search engine;
obtaining a second relevance ranking of the taxonomy item in the particular data file using a second search engine that is different from the first search engine;
receiving a first user-controllable weighting factor to apply to the first relevance ranking obtained using the first search engine;
receiving a second user-controllable weighting factor to apply to the second relevance ranking obtained using the second search engine;
normalizing the first relevance ranking and the second relevance ranking;
responsive to the first relevance ranking satisfying a relevance threshold, obtaining a third relevance ranking based on the first relevance ranking, the first user-controllable weighting factor, the second relevance ranking, and the second user-controllable weighting factor;
storing the particular data file and the third relevance ranking for future use;
obtaining a fourth relevance ranking of the taxonomy item in an additional data file using the first search engine;
obtaining a fifth relevance ranking of the taxonomy item in the additional data file using the second search engine;
obtaining a sixth relevance ranking based on the fourth relevance ranking and the fifth relevance ranking; and
producing search results for the particular data file and the additional data file based on the third relevance ranking and the sixth relevance ranking,
wherein each of the first relevance ranking and the second relevance ranking are not based on data files other than the particular data file.
2. The method of claim 1, wherein the third relevance ranking is based on an average of the first relevance ranking and the second relevance ranking.
3. The method of claim 1, wherein the first relevance ranking is based on metadata of the particular data file.
4. The method of claim 1, wherein the first relevance ranking is based on a full text search of the particular data file.
5. A system comprising:
a processor; and
a memory storing instructions executable by the processor to:
obtain a first relevance ranking of a taxonomy item in a particular data file using a first search engine;
obtain a second relevance ranking of the taxonomy item in the particular data file using a second search engine that is different from the first search engine;
receive a first user-controllable weighting factor to apply to the first relevance ranking obtained using the first search engine;
receive a second user-controllable weighting factor to apply to the second relevance ranking obtained using the second search engine;
normalize the first relevance ranking and the second relevance ranking;
responsive to the first relevance ranking satisfying a relevance threshold, obtain a third relevance ranking based on the first relevance ranking, the first user-controllable weighting factor, the second relevance ranking, and the second user-controllable weighting factor;
store the particular data file and the third relevance ranking for future use;
obtain a fourth relevance ranking of the taxonomy item in an additional data file using the first search engine;
obtain a fifth relevance ranking of the taxonomy item in the additional data file using the second search engine;
obtain a sixth relevance ranking based on the fourth relevance ranking and the fifth relevance ranking; and
produce search results for the particular data file and the additional data file based on the third relevance ranking and the sixth relevance ranking,
wherein each of the first relevance ranking and the second relevance ranking are not based on data files other than the particular data file.
6. A non-transitory computer-readable storage medium storing instructions that, when executed by a processor, cause a computer to:
obtain a first relevance ranking of a taxonomy item in a particular data file using a first search engine;
obtain a second relevance ranking of the taxonomy item in the particular data file using a second search engine that is different from the first search engine;
receive a first user-controllable weighting factor to apply to the first relevance ranking obtained using the first search engine;
receive a second user-controllable weighting factor to apply to the second relevance ranking obtained using the second search engine;
normalize the first relevance ranking and the second relevance ranking;
responsive to the first relevance ranking satisfying a relevance threshold, obtain a third relevance ranking based on the first relevance ranking, the first user-controllable weighting factor, the second relevance ranking, and the second user-controllable weighting factor;
store the third relevance ranking;
obtain a fourth relevance ranking of the taxonomy item in an additional data file using the first search engine;
obtain a fifth relevance ranking of the taxonomy item in the additional data file using the second search engine;
obtain a sixth relevance ranking based on the fourth relevance ranking and the fifth relevance ranking; and
produce search results for the particular data file and the additional data file based on the third relevance ranking and the sixth relevance ranking,
wherein each of the first relevance ranking and the second relevance ranking are not based on data files other than the particular data file.
7. The computer-readable storage medium of claim 6, further comprising instructions that, when executed by the computer, cause the computer to obtain the third relevance ranking based on an average of the first relevance ranking and the second relevance ranking.
8. The computer-readable storage medium of claim 6, further comprising instructions that, when executed by the computer, cause the computer to base the first relevance ranking on whether the taxonomy item or a term related to the taxonomy item appears in metadata of the particular data file.
9. The computer-readable storage medium of claim 6, further comprising instructions that, when executed by the computer, cause the computer to base the first relevance ranking on an imported relevance ranking in the particular data file from a supplier of the particular data file.
10. The method of claim 1, wherein the third relevance ranking is stored as metadata of the particular data file.
11. The method of claim 1, further comprising:
sending a plurality of normalized relevance rankings to a display device to enable a user to compare efficacies of a plurality of search engines.
12. The method of claim 1, wherein the first relevance ranking is included in the particular data file by a supplier of the particular data file.
13. The method of claim 1, wherein the first relevance ranking is based on a frequency that one or more terms associated with the taxonomy item appear in text of the particular data file.
14. The method of claim 1, wherein the first relevance ranking is based on where one or more terms associated with the taxonomy item appear in text of the particular data file.
15. The method of claim 1, wherein the first relevance ranking is based on whether one or more terms associated with the taxonomy item appear in metadata of the particular data file.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An AC motor driving circuit for driving an AC motor from an AC power supply and a DC power supply, which is configured to feed and absorb electric power, the AC motor driving circuit comprising:
a matrix converter configured to perform power conversion between the AC power supply and the AC motor, the matrix converter being connected between an output of the AC power supply and an input of the AC motor;
a power conversion circuit configured to perform power conversion between the DC power supply and the AC motor, the power conversion circuit including a plurality of series connection circuits in each of which a unidirectional switch is connected back-to-back with a diode, and a first bidirectional switch is connected in series with the unidirectional switch, a junction between each unidirectional switch and the respective first bidirectional switch being connected to an input phase of the AC motor, a terminal of each unidirectional switch not connected to the respective first bidirectional switch being connected to a first terminal of the DC power supply, and a terminal of each first bidirectional switch not connected to the respective unidirectional switch being connected to a second terminal of the DC power supply.
2. The AC motor driving circuit according to claim 1, wherein a number of the series connection circuits is the same as a number of the input phases of the AC motor.
3. An electric car driving circuit comprising the AC motor driving circuit according to claim 1, wherein the AC power supply is an AC power generator driven by an internal combustion engine.
4. The AC motor driving circuit according to claim 1, further comprising means for turning off the first bidirectional switches in the power conversion circuit when the matrix converter is operated.
5. The AC motor driving circuit according to claim 4, the matrix converter further comprising second bidirectional switches, wherein one terminal of each of the second bidirectional switches is connected to one of the input phases of the AC motor, and wherein the AC motor driving circuit further comprises means for turning off the second bidirectional switches when the power conversion circuit is operated.
6. The AC motor driving circuit according to claim 5, wherein the DC power supply is charged with electric power regenerated from the AC motor, while the second bidirectional switches in the matrix converter are turned off.
7. The AC motor driving circuit according to claim 5, wherein a first period in which the matrix converter performs power conversion between the AC power supply and the AC motor and a second period in which the power conversion circuit performs power conversion between the DC power supply and the AC motor are controlled in such a time division manner that the unidirectional switches and the first bidirectional switches in the power conversion circuit are turned off during the first period while the second bidirectional switches in the matrix converter are turned off during the second period.
8. The AC motor driving circuit according to claim 7, wherein the first period and second period are controlled using a PWM (Pulse Width Modulation) signal generating circuit.
9. An AC motor driving circuit for driving an AC motor, comprising:
an AC power supply;
a DC power supply configured to feed and absorb electric power;
a matrix converter configured to perform power conversion between the AC power supply and the AC motor, the matrix converter being connected between an output of the AC power supply and an input of the AC motor; and
a power conversion circuit configured to perform power conversion between the DC power supply and the AC motor, the power conversion circuit including a plurality of series connection circuits in each of which a unidirectional switch is connected back-to-back to a diode, and a first bidirectional switch is connected in series with the unidirectional switch, a junction between the unidirectional switch and the respective first bidirectional switch being connected to an input phase of the AC motor, a terminal of each unidirectional switch not connected to the respective first bidirectional switch being connected to a first terminal of the DC power supply, and a terminal of each first bidirectional switch not connected to the respective unidirectional switch being connected to a second terminal of the DC power supply.
10. The AC motor driving circuit according to claim 9, wherein a number of the series connection circuits is the same as a number of the input phases of the AC motor.
11. An electric car driving circuit comprising
the AC motor driving circuit according to claim 9, wherein the AC power supply is an AC power generator driven by an internal combustion engine.
12. The AC motor driving circuit according to claim 9, further comprising means for turning off the first bidirectional switches in the power conversion circuit when the matrix converter is operated.
13. The AC motor driving circuit according to claim 12, the matrix converter further comprising second bidirectional switches, wherein one terminal of each of the second bidirectional switches is connected to one of the input phases of the AC motor, and wherein the AC motor driving circuit further comprises means for turning off the second bidirectional switches when the power conversion circuit is operated.
14. The AC motor driving circuit according to claim 13, wherein the DC power supply is charged with electric power regenerated from the AC motor, while the second bidirectional switches in the matrix converter are turned off.
15. The AC motor driving circuit according to claim 13, wherein a first period in which the matrix converter performs power conversion between the AC power supply and the AC motor and a second period in which the power conversion circuit performs power conversion between the DC power supply and the AC motor are controlled in such a time division manner that the switches and the first bidirectional switches in the power conversion circuit are turned off during the first period while the second bidirectional switches in the matrix converter are turned off during the second period.
16. The AC motor driving circuit according to claim 15, wherein the first period and second period are controlled using a PWM (Pulse Width Modulation) signal generating circuit.