JP2010186214A - Retrieval device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retrieval method for achieving highly precise retrieval while suppressing the load of an operation in a user. <P>SOLUTION: A query accepting part 11 accepts a query for retrieval, and transmits it to a first retrieval engine 41 and second retrieval engines 42 to 44. The first retrieval engine 41 obtains a first retrieval result on the basis of the query, and the second retrieval engines 42 to 44 obtain a second retrieval result on the basis of the query. A ranking adjusting part 13 changes the ranking of the first retrieval result on the basis of the similarity of the first retrieval result and the second retrieval result. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for retrieving data related to a query. In particular, the present invention relates to a search technique suitable for Web search.

  Patent Document 1 below discloses a Web search technique using a query. In this technique, various types of documents (generally including text and images) existing in the Web are acquired in advance by a technique called crawling and stored in a database. At the time of accumulation, indexing considering the ease of search is performed.

  In this technique, when a user inputs a query to the user terminal, the search engine searches the database based on the query and returns a similar Web document to the user terminal as a search result.

  Further, in this technique, search results in different categories (for example, news, discussion groups, images, etc.) are acquired based on one query. Then, the search result in each category is presented to the user.

  In this technique, the user can access search results belonging to the category by specifying the category of interest. However, this technology does not display search results in each category in an integrated manner.

  On the other hand, Patent Literature 2 below describes a technique for performing a search using a composite media document as a query. In this technique, features are automatically extracted from a composite media document (a document including text and images) designated by a user, and a database is searched using the extracted features as a key. A composite media document similar to the query is acquired by previously recording in the database the composite media document to be searched and the features extracted therefrom.

  However, if a search key is automatically extracted from a composite media document having various information, search noise tends to increase. For this reason, when implementing this technique, it is considered that a device for suppressing search noise is required.

  In a general web search, a character string is input as a search key. However, in the technique of Patent Document 2, a composite media document including various contents must be input as a search key. Then, the user cannot perform a search unless preparing a composite media document similar to the document to be searched, and the search operation becomes complicated. Also, a search apparatus that accepts such a composite media document as a search key lacks versatility because the form of the query is significantly restricted.

JP-T-2007-517317 (paragraphs 0039 and 0040) JP 2000-148793 A

  The present invention has been made in view of the above situation. One of the objects of the present invention is to provide a search device or method that enables high-precision search in accordance with a user's search intention while keeping the operation burden on the user low.

  The present invention is configured as described in any of the following items.

(Item 1)
A query reception unit, a search result acquisition unit, a ranking adjustment unit, and a search result output unit;
The query reception unit is configured to receive a query for search sent from a user terminal and send the query to the first search engine and the second search engine, respectively.
The first search engine is configured to generate a ranked first search result by searching a Web document based on the query.
The second search engine is configured to generate a second search result by searching multimedia data based on the query.
The multimedia data includes an image or sound,
The search result acquisition unit is configured to acquire the first search result in the first search engine and the second search result in the second search engine, respectively.
The ranking adjustment unit is configured to calculate a similarity between the first search result from the first search engine and the second search result from the second search engine, and to calculate the similarity according to the calculated similarity. It is configured to perform processing for generating a third search result by changing the ranking in one search result,
The search result output unit displays the first search result ranked by the first search engine in parallel with the third search result whose ranking has been changed by the ranking adjustment unit. A search apparatus comprising: a process for generating a display document; and a process for outputting the display document to the user terminal.

  According to the present invention, the first search result obtained by the first search engine can be ranked using the second search result obtained by the second search engine. Thereby, in this invention, the improvement of search accuracy can be expected, and the burden on the operator can be kept low. There can be a plurality of second search engines.

(Item 2)
A plurality of the second search engines exist,
The ranking adjustment unit
Integrating respective similarities between the first search result by the first search engine and the plurality of second search results by the plurality of second search engines, and based on the integrated similarity The search device according to item 1, wherein the search device is configured to perform ranking.

(Item 3)
The search device according to item 1 or 2, wherein the second search engine is any one of an image search engine, a video search engine, and a product search engine, or a combination thereof.

(Item 4)
The ranking adjustment unit
A process of referring to the second search result by the second search engine according to the type of content included in the search result by the first search engine;
When the degree of similarity with the second search result by the second search engine is high, the processing for increasing the rank of the first search result by the first search engine is performed. The search device according to any one of the above.

(Item 5)
The search device according to any one of items 1 to 4, wherein the search result by the first search engine includes any one of text, image, and sound, or a combination thereof.

(Item 6)
A first search engine and a second search engine receiving a common query for search;
The first search engine generating a ranked first search result by searching a web document based on the query;
The second search engine generates a second search result by searching multimedia data based on the query;
Wherein the multimedia data includes images or sounds;
Calculating a similarity between the first search result obtained by the first search engine and the second search result obtained by the second search engine;
Generating a third search result by changing the ranking in the first search result according to the calculated similarity;
Generating a display document for displaying in parallel the first search result ranked by the first search engine and the third search result whose ranking has been changed by the ranking adjustment unit. When;
And a step of outputting the display document to a user terminal.

(Item 7)
A computer program that causes a computer to execute the steps according to item 6.

  This computer program is stored in an appropriate recording medium (for example, an optical recording medium such as a CD-ROM or a DVD disk, a magnetic recording medium such as a hard disk or a flexible disk, or a magneto-optical recording medium such as an MO disk). Can be stored. This computer program can be transmitted via a communication line such as the Internet.

  According to the present invention, it is an object of the present invention to provide a search device or method that enables high-precision search while keeping a burden of operation on a user low.

It is a block diagram which shows the basic composition of the search device which concerns on one Embodiment of this invention. 3 is a flowchart for explaining a basic operation in the search device of FIG. 1. It is explanatory drawing for demonstrating the basic operation | movement in the search device of FIG. It is a flowchart for demonstrating the ranking method in the search device of FIG. It is explanatory drawing for demonstrating the ranking method in the search device of FIG. It is explanatory drawing for demonstrating the ranking method in the search device of FIG. It is explanatory drawing for demonstrating the ranking method in the search device of FIG. FIG. (A) shows a search result by the Web search engine. Figure (b) shows the reranked search results. It is explanatory drawing for demonstrating the modification 1 regarding calculation of a multimedia similarity. It is explanatory drawing for demonstrating the modification 2 regarding calculation of a multimedia similarity.

(Device configuration of this embodiment)
A search device according to an embodiment of the present invention will be described with reference to the accompanying drawings. The apparatus according to the present embodiment performs a Web search using a query.

  The search device of this embodiment is implemented as a search mediation server 1 (see FIG. 1). The search mediation server 1 includes a query reception unit 11, a search result acquisition unit 12, a ranking adjustment unit 13, and a search result output unit 14.

  The search mediation server 1 is connected to the Internet 2. Further, a user terminal 3 for sending a query to the search mediation server 1 and a search execution server 4 for executing a search are further connected to the Internet 2. These nodes can be connected by a network other than the Internet.

(Description of search mediation server 1)
The query acceptance unit 11 of the search mediation server 1 accepts a query for search sent from the user terminal 3, and a first search engine (Web search engine) and a second search engine (other search engines) to be described later. ) And send to each. The first search engine is configured to generate a ranked first search result by searching a Web document based on the query. The second search engine is configured to generate a second search result by searching multimedia data based on the query. Details of these search engines will be described in detail later as operations of the present embodiment. Note that the multimedia data in the present embodiment includes images or sounds.

  The search result acquisition unit 12 is configured to acquire a first search result in the first search engine and a second search result in the second search engine, respectively. The search result acquisition unit 12 will be described in detail later.

  The ranking adjustment unit 13 calculates the rank in the first search result based on the process of calculating the similarity between the first search result by the first search engine and the second search result by the second search engine, and the calculated similarity. By changing the attachment, the third search result is generated. This will be described in detail later.

  The search result output unit 14 displays a display document for displaying in parallel the first search result ranked by the first search engine and the third search result whose ranking has been changed by the ranking adjustment unit. The process of generating and the process of outputting the display document to the user terminal 3 are performed.

(Description of user terminal 3)
The user terminal 3 is for receiving an input of a query by a user and sending the input query to the search server 1.

  The user terminal 3 includes a terminal main body 31, an input unit 32, and a display unit 33.

  The terminal body 31 includes a CPU, a network interface, an input / output interface, and the like, and can control the operation of the user terminal 3. As such a terminal body 31, a normal personal computer can be used.

  The input unit 32 is a part for a user to input a command to the terminal main body 31. For example, a keyboard or a mouse can be used as the input unit 32. In the present embodiment, the user can input a query using the input unit 32.

  The display unit 33 can display the search result (that is, the display document) returned from the search mediation server 1 to the user. As the display unit 33, for example, various displays and printers can be used.

(Description of search execution server)
The search execution server 4 includes a Web search engine 41, an image search engine 42, a moving image search engine 43, and a product search engine 44. Each of the search engines 41 to 44 is configured to acquire a search result based on a given query.

  The Web search engine 12 searches for Web documents. A specific example of the Web search engine is Yahoo (registered trademark) search. As an example of Web search, there is a method in which Web documents with indexes are accumulated in a database, and Web documents are searched based on the similarity between a query and an index. An example of an index is text extracted from a Web document.

  The image search engine 42 searches for images on the Internet. A specific example is Yahoo (registered trademark) image search. As an example of the image search, there is a method in which an indexed image is stored in a database and the image is searched based on the similarity between the query and the image. An example of the index is a word (so-called tag or label) representing the feature of the image. However, the stored image can be searched using the feature amount of the image.

  The video search engine 43 searches for videos on the Internet. A specific example is Yahoo (registered trademark) video search. As an example of the moving image search, there is a method in which a moving image with an index is accumulated in a database and the moving image is searched based on the similarity between the query and the moving image. An example of the index is a word (so-called tag or label) representing the feature of the moving image. However, it is also possible to search the stored moving image using the feature amount of the image and sound constituting the moving image.

  The product search engine 44 searches for information including any of text, images, and sounds on a sales site on the Internet. A specific example is Yahoo (registered trademark) product search. As an example of product search, Web documents for product sales are stored in an indexed state in a database, and Web products for product sales are searched based on the similarity between the query and the index. There is something. An example of the index is text extracted from a Web document for sale of merchandise. However, the product search engine may perform a search based on image or audio information included in a Web document for product sales.

  Each of the search engines 41 to 44 includes databases 411 to 441 that store data to be searched. Each database 411 to 441 stores data collected by crawling on the Internet in advance. Alternatively, each database 411 to 441 stores data collected by the service provider. The data stored in each of the databases 411 to 441 is provided with an index for performing an efficient search. For example, when text is used as a query, an image search label is generally registered in a database in a state corresponding to the image. Similarly, such labeling can be performed when the search target is a moving image or audio. Since the configuration of such databases 411 to 441 may be the same as that in a conventional search engine, detailed description thereof is omitted. In the present embodiment, the Web search engine 41 corresponds to an example of a first search engine, and the other search engines 42 to 44 correspond to an example of a second search engine.

(Ranking adjuster 13)
The ranking adjustment unit 13 is configured to change the ranking in the first search result with respect to the first search result by the Web search engine 41 according to the similarity with the second search result by the other search engines 42 to 44. ing. The result of changing the ranking corresponds to an example of the third search result in the present invention. In this way, in this embodiment, the first search is performed based on the process of calculating the similarity between the first search result by the first search engine and the second search result by the second search engine, and the calculated similarity. By changing the ranking in the results, the third search result is generated.

  More detailed operation of the ranking adjustment unit 13 will be described later.

(Operation of this embodiment)
Next, the operation of the search mediation server 1 according to the present embodiment will be described with reference mainly to FIG. 2 and FIG.

(Step SA-1 in FIG. 2)
First, the user inputs a query using the input unit 32 of the user terminal 3. In this embodiment, text is used as the query. The query input at the user terminal 3 is sent to the query reception unit 11 of the search mediation server 1 via the Internet 2 (step SB-1 in FIG. 3).

(Step SA-2 in FIG. 2)
Next, the query receiving unit 11 sends a query to each search engine 41 to 44 of the search execution server 4.

(Step SA-3 in FIG. 2)
The search engines 41 to 44 that have received the query acquire search results according to their search algorithms (steps SB-2 and SB-3 in FIG. 3). Since the search processing in each search engine may be the same as that of a conventional search engine, detailed description is omitted.

  Thereby, a list of search results can be acquired corresponding to the search in each of the search engines 41 to 44. In this embodiment, a search result by the Web search engine 41 is referred to as a first search result, and a search result by the other search engines 42 to 44 is referred to as a second search result. Each search result is sent to the search result acquisition unit 12 of the search mediation server 1 via the Internet 2.

(Step SA-4 in FIG. 2)
After acquiring the first search result and the second search result, the search result acquisition unit 12 sends these search results to the ranking adjustment unit 13. Next, the ranking adjustment unit 13 adjusts the ranking for the first search result by the Web search engine 41 (step SB-4 in FIG. 3). This adjustment may be referred to as “re-ranking”.

  The detailed reranking procedure will be described in more detail with reference to FIGS.

(Step SC-1 in FIG. 4)
First, the multimedia similarity between the first search result by the Web search engine 41 and the second search results by the other search engines 42 to 44 is calculated.

  FIG. 5 shows a list of first search results by the Web search engine 41 (FIG. 5A), a list of second search results by the image search engine 42 (FIG. 5B), and a second list by the video search engine 43. A list of search results (FIG. (C)) and a list of second search results by the product search engine 44 (FIG. (D)) are shown.

  In each search result list, as shown in FIG. 5, ranking is performed according to the algorithm of each search engine. FIG. 5 shows search results for the top N items (N is an arbitrary natural number). The value of N may be different or the same for each search engine.

  In the example of FIG. 5, the first order search result (so-called Web document) by the Web search engine includes one text and two images. The second ranking search result (so-called Web document) includes two moving images and one text.

  Here, it is assumed that one item in the search list by the Web search engine 41 includes two images and one moving image as contents, as shown in FIG. In this case, the search result by the image search engine 42 (FIG. 6B) and the search result by the moving image search engine 43 (FIG. 6C) are referred to corresponding to the included content. This will be described in detail below.

  First, for the image, the similarity between the image included in the search result by the Web search engine 41 and the image as the search result by the image search engine 42 is calculated (FIG. 6D). Specifically, in this embodiment, the similarity between each image in the Web search result and each image in the image search result is calculated. Then, the average of the obtained maximum similarity is used as the image similarity.

  That is, the image similarity in this embodiment is as follows. Here, Max {} means a function for selecting the maximum value, and similarity () means a function for calculating similarity.

  Image similarity = [MAX {similarity (image A, image 1), similarity (image A, image 2), similarity (image A, image 3), similarity (image A, image 4)} + MAX {similarity Degree (image B, image 1), similarity (image B, image 2), similarity (image B, image 3), similarity (image B, image 4)}] / 2.

  Similarly, the moving image similarity is calculated as follows (FIG. 6E).

  Movie similarity = MAX {similarity (movie A, movie 1), similarity (movie A, movie 2)}.

  Each similarity can be calculated by an existing calculation method. For example, in the case of image data, a technique of extracting visual feature amounts such as color, shape, and texture from image data and calculating a similarity is common. Therefore, a detailed description of the similarity calculation method is omitted (reference: "Content-based Multimedia Information Retrieval: State of the Art and Challenges", ACM Transactions on Multimedia Computing, Communications, and Applications, 2 (1): 1-19, Feb. 2006.). Each similarity value is preferably normalized with respect to the maximum similarity in each medium (for example, by text or image type).

  In this embodiment, the multimedia similarity is calculated as follows.

  Multimedia similarity = (image similarity + moving image similarity) / 2.

  That is, the multimedia similarity is calculated as an average of the obtained similarities. Such multimedia similarity calculation is performed for each search result by the Web search engine. Even when speech or text is included in the searched items, the multimedia similarity can be calculated in the same manner.

(Step SC-2 in FIG. 4)
Next, the ranking adjustment unit 13 rearranges the rankings of the first search results by the Web search engine 41 based on the obtained multimedia similarity. FIG. 7A shows a state before rearrangement, and FIG. 7B shows a state after rearrangement. The state in which the rankings are rearranged corresponds to the third search result in the present invention.

Such processing is
“The ranking adjustment unit ranks the first search result according to the process of calculating the similarity between the first search result by the first search engine and the second search result by the second search engine, and the calculated similarity. The process of generating the third search result by changing
It corresponds to an example.

(Step SA-5 in FIG. 2)
Next, the search result output unit 14 in the search mediation server 1 displays in parallel the first search result ranked by the Web search engine 41 and the third search result whose ranking has been changed by the ranking adjustment unit 13. A display document is generated for this purpose. An example of generating a display document is shown in FIG. In FIG. 7, the part of FIG. 7A corresponds to the first search result, and the part of FIG. 7B corresponds to the third search result. The display document preferably displays a link or URL (not shown) for accessing the original Web site from which each item was acquired.

  Thus, by displaying the first search result and the third search result in parallel, the user can easily understand the search result. In addition, since the third search result is displayed in a pair with the first search result, when the search result is displayed as a list by URL, title, or the like, the ranking includes the images, sounds, and videos related to the query. It is easy to check the changed website.

  Further, the search result output unit 14 outputs the generated display document toward the user terminal 3. The user terminal 3 displays the display document (that is, the search result) sent from the search mediation server 1 by appropriate software such as a browser. The user can access desired information by an appropriate means such as clicking a URL attached to the search result.

  In this embodiment, the query is expanded to each search engine, and the same query is used for output based on the similarity between the first search result by the Web search engine and the second search result by another search engine. The ranking of the third search result is determined. In addition, the ranking of the third search result is adjusted in consideration of the similarity between the multimedia data included in the first search result and the multimedia data included in the second search result. For this reason, according to the present embodiment, it is possible to acquire an accurate search result according to the user's search intention while suppressing search noise to a low level.

  Further, in the present embodiment, the query can be automatically developed in the search engine, and the search results can be automatically integrated, so that there is an advantage that the operation burden on the user can be kept low.

(Modification 1 in similarity calculation)
In the following, another processing procedure in the calculation of the multimedia similarity will be described with reference to FIG.

((A) of FIG. 8)
First, as in the above-described embodiment, the first search result by the Web search engine 41 is acquired, and the results of the top K items are acquired as a list on the system side. In the illustrated example, up to the top four are acquired as a list.

((B) of FIG. 8)
Next, similar to the above-described embodiment, the similarity between the second search result obtained by each of the search engines 42 to 44 and the first search result is calculated. In the example of FIG. 8B, the similarity between the image search result (second search result), the video search result (second search result), and the product search result (second search result) and the first search result is calculated. Each example is shown. In this example, “none” is described when there is no corresponding content in the first search result. For example, in the item (1) as the Web search result, there is no moving image (see FIG. 8A), so “None” is described in the “moving image similarity” item.

((C) in FIG. 8)
Next, the similarity in each medium (image, moving image, product in the above example) is converted into a rank (rank). Here, the highest similarity is rank = 1, the next similarity is rank = 2, and so on. When the similarity is “none”, the rank is set to “K + 1” in this example. “K” is the number of items in the web search result list (that is, the first search result), and in this example, K = 4. Further, an average rank is calculated for each item (see the rightmost column in FIG. 8C). It can be considered that this average rank corresponds to the multimedia similarity.

((D) in FIG. 8)
Next, the items in the Web search result list are sorted in the order of the average rank. This sort is called re-ranking here. A low rank indicates a high similarity in this example.

  It can be said that the result of re-ranking in this way represents the ranking based on the multimedia similarity. In the case of this method, even if the Web search result is not high in individual similarity with each media, the search result list after re-ranking (that is, the first search result) is included by including many media (images, videos, products). (3 search results) tend to be higher.

  The method of the first modification has an advantage that re-ranking using multimedia similarity can be performed without performing normalization of similarity.

(Modification 2 in similarity calculation)
In the following, still another processing procedure for calculating the multimedia similarity will be described with reference to FIG.

((A) of FIG. 9)
First, as in the first modification, the first search result by the Web search engine 41 is acquired, and the results of the top K items are acquired as a list on the system side. In the illustrated example, up to the top four are acquired as a list.

((B) of FIG. 9)
Next, similar to the first modification described above, the similarity with the second search result obtained by each of the search engines 42 to 44 is calculated.

((C) of FIG. 9)
Next, as in the first modification, the similarity in each medium (image, moving image, product in the above example) is converted into a rank (rank). However, in the second modification, when the similarity is “none”, the rank is also set to “none”. Further, an average rank is calculated for each item (see the rightmost column in FIG. 9C). It can be considered that this average rank corresponds to the multimedia similarity.

((D) in FIG. 9)
Next, the items in the Web search result list (first search result) are sorted in the order of the average rank, that is, reranked. A low rank indicates a high degree of similarity. It can be said that the result of re-ranking in this way represents the ranking based on the multimedia similarity.

  In the case of the method of the second modification, even if many media are not included, a web page having a high similarity to a certain media tends to be higher in the search result list after re-ranking (third search result). .

  The method of the second modification also has an advantage similar to that of the first modification in that re-ranking using multimedia similarity is possible without normalizing the similarity.

  The operations of the above-described embodiments can be implemented by incorporating appropriate computer software into the computer.

  The contents of the present invention are not limited to the above embodiment. In the present invention, various modifications can be made to the specific configuration within the scope of the claims.

  For example, each component described above may exist as a functional block, and may not exist as independent hardware. As a mounting method, hardware or computer software may be used. Furthermore, one functional element in the present invention may be realized by a set of a plurality of functional elements, and a plurality of functional elements in the present invention may be realized by one functional element.

  Moreover, the functional element may be arrange | positioned in the position physically separated. In this case, the functional elements may be connected by a network. It is also possible to realize functions or configure functional elements by grid computing.

  In this embodiment, text is used as a query, but other queries such as images can be used as long as they can be used as search keys.

  Furthermore, in the present embodiment, a search engine for images, moving images, and products is used as the second search engine other than the Web search engine (first search engine), but instead of or in addition to this, Search engines for other media such as music, news, blogs and maps can also be used.

1 Search mediation server (search device)
DESCRIPTION OF SYMBOLS 11 Query reception part 12 Search result acquisition part 13 Ranking adjustment part 14 Search result output part 3 User terminal 31 Terminal main body 32 Input part 33 Display part 4 Search execution server 41 Web search engine (1st search engine)
42 Image search engine (second search engine)
43 Video search engine (second search engine)
44 Product search engine (second search engine)

Claims (7)

A query reception unit, a search result acquisition unit, a ranking adjustment unit, and a search result output unit;
The query reception unit is configured to receive a query for search sent from a user terminal and send the query to the first search engine and the second search engine, respectively.
The first search engine is configured to generate a ranked first search result by searching a Web document based on the query.
The second search engine is configured to generate a second search result by searching multimedia data based on the query.
The multimedia data includes an image or sound,
The search result acquisition unit is configured to acquire the first search result in the first search engine and the second search result in the second search engine, respectively.
The ranking adjustment unit is configured to calculate a similarity between the first search result from the first search engine and the second search result from the second search engine, and to calculate the similarity according to the calculated similarity. It is configured to perform processing for generating a third search result by changing the ranking in one search result,
The search result output unit displays the first search result ranked by the first search engine in parallel with the third search result whose ranking has been changed by the ranking adjustment unit. A search apparatus comprising: a process for generating a display document; and a process for outputting the display document to the user terminal. A plurality of the second search engines exist,
The ranking adjustment unit
Integrating respective similarities between the first search result by the first search engine and the plurality of second search results by the plurality of second search engines, and based on the integrated similarity The search device according to claim 1, wherein the search device is configured to perform ranking. The search device according to claim 1, wherein the second search engine is any one of an image search engine, a video search engine, and a product search engine, or a combination thereof. The ranking adjustment unit
A process of referring to the second search result by the second search engine according to the type of content included in the search result by the first search engine;
The process of increasing the rank of the first search result by the first search engine when the degree of similarity with the second search result by the second search engine is high. 4. The search device according to any one of 3 above. The search device according to any one of claims 1 to 4, wherein the search result by the first search engine includes any one of text, image and sound, or a combination thereof. A first search engine and a second search engine receiving a common query for search;
The first search engine generating a ranked first search result by searching a web document based on the query;
The second search engine generates second search results by searching multimedia data based on the query;
Wherein the multimedia data includes images or sounds;
Calculating a similarity between the first search result obtained by the first search engine and the second search result obtained by the second search engine;
Generating a third search result by changing the ranking in the first search result according to the calculated similarity;
Generating a display document for displaying in parallel the first search result ranked by the first search engine and the third search result whose ranking has been changed by the ranking adjustment unit. When;
And a step of outputting the display document to a user terminal.   A computer program for causing a computer to execute the steps according to claim 6.

Images