1. A question answering system comprising:
a similar-question generation unit that selects a feature word from an input question to generate a transformational question in which the feature word is replaced with another word;
a first search unit that executes a first search process based on the transformational question generated by the similar-question generation unit;
a second search unit that selects a word included in a first search result acquired by executing the first search process as an extension word and executes a second search process with using the selected extension word; and
an answer selection unit that analyzes a correspondence relation among extension words included in a second search result acquired by executing the second search process, determines the feature word and a constructive part of an answer equivalent word in the second search result based on an analysis result, and selects for display a word determined to be an answer; and
a display unit that displays the selected word.
2. The question answering system according to claim 1, wherein the answer selection unit analyzes the correspondence relation among the extension words based on HTML format data, which is acquired as the second search result acquired, determines the feature word and the constructive part of the answer equivalent word in the second search result based on the analysis result, and selects the word determined to be the answer.
3. The question answering system according to claim 1 wherein:
the similar-question generation unit generates a transformational question pattern 1, which is a similar question to the input question, without changing the feature word making up the input question,
the first search unit executes a search process based on the transformational question pattern 1, and
if no answer is acquired as a result of the search process based on the transformational question pattern 1,
the similar-question generation unit generates as the transformational question a transformational question pattern 2 in which the feature word making up the input question is replaced with a same-group word belonging to the same group in a thesaurus as the feature word;
the first search unit executes the first search process based on the transformational question pattern 2; and
the second search unit selects the word included in the first search result acquired by executing the first search process as the extension word and executes the second search process with using the selected extension word.
4. The question answering system according to claim 1, wherein:
the second search unit selects (a) a same-group word, which is selected from words included in the first search result and belongs to the same group as the feature word, and (b) an answer equivalent word in the transformational question as the extension words, and
the second search unit executes the second search process with using the selected extension words.
5. The question answering system according to claim 1, further comprising:
a first storage unit that stores question patterns; and
a second storage unit that stores transformational patterns of the question patterns stored in the first storage unit, wherein:
the similar-question generation unit compares the input question with the question patterns stored in the first storage unit to select a question pattern corresponding to the input question, and
the similar-question generation unit generates the transformational question corresponding to the selected question pattern, based on the transformational patterns stored in the second storage unit.
6. The question answering system according to claim 1, further comprising:
a third storage unit that stores group classification information of feature words, which are acquired from input questions as proper nouns, wherein:
the similar-question generation unit generates the transformational question in which the feature word making up the input question with a same-group word belonging to the same group as the feature word, with using the classification information stored in the third storage unit.
7. The question answering system according to claim 1, wherein the similar-question generation unit generates the transformational question in which the feature word is replaced with the other word, based on a predetermined rule.
8. The question answering system according to claim 1 further comprising:
a syntactic and semantic analysis unit that executes syntactic and semantic analysis on the input question, wherein:
the similar-question generation unit generates a question pattern based on a analysis result acquired by executing the syntactic and semantic analysis, and
the first search unit executes a search process based on the question pattern generated by the similar-question generation unit.
9. A data search method comprising:
selecting a feature word from an input question;
generating a transformational question in which the feature word is replaced with another word;
executing a first search process based on the transformational question generated;
selecting a word included in a first search result acquired by executing the first search process as an extension word;
executing a second search process with using the selected extension word;
analyzing a correspondence relation among extension words included in a second search result acquired by executing the second search process;
determining the feature word and a constructive part of an answer equivalent word in the second search result based on an analysis result;
selecting a word determined to be an answer; and
displaying the selected word.
10. The data search method according to claim 9, wherein the analyzing comprises analyzing the correspondence relation among the extension words based on HTML format data, which is acquired as the second search result acquired.
11. The data search method according to claim 9, further comprising:
generating a transformational question pattern 1, which is a similar question to the input question, without changing the feature word making up the input question,
executing a search process based on the transformational question pattern 1, and
if no answer is acquired as a result of the search process based on the transformational question pattern 1,
generating as the transformational question a transformational question pattern 2 in which the feature word making up the input question is replaced with a same-group word belonging to the same group as the feature word;
executing the first search process based on the transformational question pattern 2;
selecting the word included in the first search result acquired by executing the first search process as the extension word; and
executing the second search process with using the selected extension word.
12. The data search method according to claim 9, wherein the selecting of the word included in the first search result as the extension word comprises selecting (a) a same-group word, which is selected from words included in the first search result and belongs to the same group as the feature word, and (b) an answer equivalent word in the transformational question as the extension words.
13. The data search method according to claim 9 wherein:
the generating of the transformational question comprises:
comparing the input question with question patterns stored in a first storage unit to select a question pattern corresponding to the input question, and
generating the transformational question corresponding to the selected question pattern, based on transformational patterns stored in a second storage unit.
14. The data search method according to claim 9, wherein the generating of the transformational question comprises generating the transformation question in which the feature word making up the input question with a same-group word belonging to the same group as the feature word, with using classification information stored in a third storage unit.
15. The data search method according to claim 9, wherein the generating of the transformational question comprises generating the transformation question in which the feature word is replaced with the other word, based on a predetermined rule.
16. The data search method according to claim 9, further comprising:
executing syntactic and semantic analysis on the input question;
generating a question pattern based on a analysis result acquired by executing the syntactic and semantic analysis; and
executing a search process based on the question pattern generated.
17. A computer program stored in a computer readable medium, the computer program causing a computer to execute a data search process comprising:
selecting a feature word from an input question;
generating a transformational question in which the feature word is replaced with another word;
executing a first search process based on the transformational question generated;
selecting a word included in a first search result acquired by executing the first search process as an extension word;
executing a second search process with using the selected extension word;
analyzing a correspondence relation among extension words included in a second search result acquired by executing the second search process;
determining the feature word and a constructive part of an answer equivalent word in the second search result based on an analysis result; and
selecting a word determined to be an answer.
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. A sheet stacking apparatus, comprising:
a tray on which sheets are stacked;
an aligning member which aligns sheets, wherein the aligning member aligns the sheets stacked on sheets previously stacked on the tray with a displacement in an aligning direction of the aligning member with respect to the sheets previously stacked;
a moving unit which moves the tray so that the tray is lowered with an increase in the number of the stacked sheets;
a support unit which supports the aligning member so that the aligning member is lowered within a predetermined distance with the aligning member being in contact with a top surface of the sheets previously stacked as the tray is lowered by the moving unit; and
a changing unit which changes the aligning operation of the aligning member between a first state in which the aligning member is in contact with the top surface of the sheets previously stacked and a second state in which the number of the sheets stacked on the sheets previously stacked exceeds a predetermined number, the aligning member being spaced away from the top surface of the sheets previously stacked when the number of the sheets stacked on the sheets previously stacked exceeds the predetermined number,
wherein
the aligning member performs the aligning operation every time a first number of sheets are stacked on the tray in the first state,
the aligning member performs the aligning operation every time a second number of sheets are stacked on the tray in the second state, and
the first number is larger than the second number.
2. A sheet stacking apparatus according to claim 1, wherein in the second state, the aligning member performs the aligning operation every time a sheet is stacked.
3. A sheet stacking apparatus according to claim 1, wherein in the first state, if the aligning member is not spaced away from the top surface of the sheets previously stacked after all sheets to be stacked on the sheets previously stacked are discharged, the aligning member performs the aligning operation after all sheets are discharged.
4. A sheet stacking apparatus according to claim 1, further comprising:
a conveying unit which conveys sheets to be stacked on the tray,
wherein the conveying unit conveys a subsequent sheet to the tray with the position of the subsequent sheet being changed in an aligning direction of the aligning member with respect to a position of a preceding sheet conveyed.
5. An image forming apparatus, comprising:
an image forming unit which forms an image on a sheet;
a tray on which image-formed sheets are stacked;
an aligning member which aligns sheets, wherein the aligning member aligns the sheets stacked on sheets previously stacked on the tray with a displacement in an aligning direction of the aligning member with respect to the sheets previously stacked;
a moving unit which moves the tray so that the tray is lowered with an increase in the number of the stacked sheets;
a support unit which supports the aligning member so that the aligning member is lowered within a predetermined distance with the aligning member being in contact with a top surface of the sheets previously stacked as the tray is lowered by the moving unit; and
a changing unit which changes the aligning operation of the aligning member between a first state in which the aligning member is in contact with the top surface of the sheets previously stacked and a second state in which the number of the sheets stacked on the sheets previously stacked exceeds a predetermined number, the aligning member being spaced away from the top surface of the sheets previously stacked when the number of the sheets stacked on the sheets previously stacked exceeds the predetermined number,
wherein
the aligning member performs the aligning operation every time a first number of sheets are stacked on the tray in the first state,
the aligning member performs the aligning operation every time a second number of sheets are stacked on the tray in the second state, and
the first number is larger than the second number.
6. An image forming apparatus according to claim 5, wherein in the second state, the aligning member performs the aligning operation every time a sheet is stacked.
7. An image forming apparatus according to claim 5, wherein in the first state, if the aligning member is not spaced away from the top surface of the sheets previously stacked after all sheets to be stacked on the sheets previously stacked are discharged, the aligning member performs the aligning operation after all sheets are discharged.
8. An image forming apparatus according to claim 5, further comprising:
a conveying unit which conveys sheets to be stacked on the tray,
wherein the conveying unit conveys a subsequent sheet to the tray with the position of the subsequent sheet being changed in an aligning direction of the aligning member with respect to a position of a preceding sheet conveyed.
9. A sheet stacking apparatus, comprising:
a tray on which sheets are stacked;
an aligning member which aligns sheets, wherein the aligning member aligns the sheets stacked on sheets previously stacked on the tray with a displacement in an aligning direction of the aligning member with respect to the sheets previously stacked;
a moving unit which moves the tray so that the tray is lowered with an increase in the number of the stacked sheets;
a support unit which supports the aligning member so that the aligning member is lowered within a predetermined distance with the aligning member being in contact with a top surface of the sheets previously stacked as the tray is lowered by the moving unit; and
a changing unit which changes the aligning operation of the aligning member between a first state in which the aligning member is in contact with the top surface of the sheets previously stacked and a second state in which the number of the sheets stacked on the sheets previously stacked exceeds a predetermined number, the aligning member being spaced away from the top surface of the sheets previously stacked when the number of the sheets stacked on the sheets previously stacked exceeds the predetermined number,
wherein
the aligning member does not perform the aligning operation in the first state,
the aligning member performs the aligning operation in the second state.
10. A sheet stacking apparatus according to claim 9, wherein in the second state, the aligning member performs the aligning operation every time a sheet is stacked.
11. A sheet stacking apparatus according to claim 9, wherein in the first state, if the aligning member is not spaced away from the top surface of the sheets previously stacked after all sheets to be stacked on the sheets previously stacked are discharged, the aligning member performs the aligning operation after all sheets are discharged.
12. A sheet stacking apparatus according to claim 9, further comprising:
a conveying unit which conveys sheets to be stacked on the tray,
wherein the conveying unit conveys a subsequent sheet to the tray with the position of the subsequent sheet being changed in an aligning direction of the aligning member with respect to a position of a preceding sheet conveyed.
13. An image forming apparatus, comprising:
an image forming unit which forms an image on a sheet;
a tray on which image-formed sheets are stacked;
an aligning member which aligns sheets, wherein the aligning member aligns the sheets stacked on sheets previously stacked on the tray with a displacement in an aligning direction of the aligning member with respect to the sheets previously stacked;
a moving unit which moves the tray so that the tray is lowered with an increase in the number of the stacked sheets;
a support unit which supports the aligning member so that the aligning member is lowered within a predetermined distance with the aligning member being in contact with a top surface of the sheets previously stacked as the tray is lowered by the moving unit; and
a changing unit which changes the aligning operation of the aligning member between a first state in which the aligning member is in contact with the top surface of the sheets previously stacked and a second state in which the number of the sheets stacked on the sheets previously stacked exceeds a predetermined number, the aligning member being spaced away from the top surface of the sheets previously stacked when the number of the sheets stacked on the sheets previously stacked exceeds the predetermined number,
wherein,
the aligning member does not perform the aligning operation in the first state, and
the aligning member performs the aligning operation in the second state.
14. An image forming apparatus according to claim 13, wherein in the second state, the aligning member performs the aligning operation every time a sheet is stacked.
15. An image forming apparatus according to claim 13, wherein in the first state, if the aligning member is not spaced away from the top surface of the sheets previously stacked after all sheets to be stacked on the sheets previously stacked are discharged, the aligning member performs the aligning operation after all sheets are discharged.
16. An image forming apparatus according to claim 13, further comprising:
a conveying unit which conveys sheets to be stacked on the tray,
wherein the conveying unit conveys a subsequent sheet to the tray with the position of the subsequent sheet being changed in an aligning direction of the aligning member with respect to a position of a preceding sheet conveyed.