JP2009129178A - Information retrieval system and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retrieval system for efficiently presenting a proper content to a user from evaluation of the user and a state of the content. <P>SOLUTION: When the user requests content retrieval, a user terminal 10-1 transfers inquiry to user terminals 10-2 to 10-4, retrieves the content, performs processing by use of evaluation information stored in a content individual information storage device 11, and displays it. When the user terminal retrieves and acquires the content, correction of the evaluation information is performed, a latest state of the content is transmitted, and a network 100 is reconfigured by use of a difference of the evaluation information to improve efficiency of the retrieval. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an information search system and program, and more particularly to an information search system and program in which a plurality of node devices perform peer-to-peer (P2P) type communication.

In recent years, content information (hereinafter referred to as content) is shared using a peer-to-peer information sharing / search system via a network such as the Internet. However, peer-to-peer type content sharing is often inconvenient for content providers in terms of content management because the content is distributed and requires a large capacity storage device and high-performance processing device for each node. Therefore, there are many problems such as being unable to use in a small information terminal such as a portable terminal. Therefore, in content distribution, a large amount of content is held in the server device, the content is distributed in response to requests from a plurality of client devices, and the target content is searched from the large amount of content held in the server device. An information distribution / retrieval system using a peer-to-peer type information retrieval system can be easily considered as a means for specifying the information.
As an example of an information search system, first, a search system that refers to data listing summary information (content name and type) that outlines the content held in each server device is prepared, and search is performed using the summary information as a condition. Means for doing this are known. There is also known a system that stores not only the content summary information but also evaluation information of each user for the content, which is used as a reference when the user searches for the content. These are mainly used to search for content in a server device of a specific content provider.

  In addition, a search engine device is used when searching for content across a plurality of server devices. The search engine device collects content index information (hereinafter referred to as an index) from a plurality of server devices, and searches the index information to obtain a large amount of information held across the server devices of a plurality of content providers. Search for content at once. Furthermore, the display order of the search results can be changed according to the content evaluation information. However, in a search system using a search engine device, the service depends on a single server device.

  In order to solve this problem, an information sharing / retrieval system using a peer-to-peer technology as described in Non-Patent Document 1 and Non-Patent Document 2 has been devised. In a peer-to-peer search system, instead of managing content index information with a single server device, an index is distributed and stored using a distributed information storage system disclosed in Non-Patent Document 1. Further, a method of performing information retrieval using a broadcast represented by Gnutella shown in Non-Patent Document 2 is considered.

  First, with reference to FIG. 1 and FIG. 2, the P2P network comprised of many user terminals is demonstrated. Here, FIG. 1 is a block diagram of a peer-to-peer network. FIG. 2 is a flowchart illustrating a procedure for joining a peer-to-peer network.

  In FIG. 1, the P2P network 100 is composed of 13 user terminals 10. An initial node management server 30 is connected to the P2P network 100. The initial node management server 30 holds a plurality of user terminal connection information DBs 31 of the P2P network. The user terminal 10A who wishes to newly join the P2P network 100 first accesses the initial node management server 30, acquires information on the initial node (initially connected user terminal), and participates in the P2P network 100. In FIG. 1, in the P2P network 100, the user terminals 10 establish communication with a maximum of three user terminals.

  In FIG. 2, the user terminal 10A newly participating in the P2P network 100 determines whether or not the user terminal 10 that has already participated in the P2P network 100 holds information (S501). Since the normal step 501 is NO, the user terminal 10A accesses the initial node management server 30 and acquires initial node information (S502). The case where step 501 is YES is when the IP address of the initial node is set in advance in the user terminal 10A.

  The user terminal 10A connects to the user terminal 10 set as the initial node (S503). The user terminal 10A determines whether the connection is successful (S504). When YES, the user terminal 10A acquires information on the connected user terminal 10 (S505). When NO in step 504, the user terminal 10A jumps in step 505. The user terminal 10A determines whether the terminal connection number is the upper limit (S506). The user terminal 10A ends when YES, and determines whether there is terminal information set in another initial node when NO (S507). The user terminal 10A returns to step 503 when YES, and ends when NO.

  As a problem in performing information search in such a network using P2P, there is a point that a large amount of search results are responded to a search request, and the user is forced to find necessary information. In order to improve this, Patent Document 1 discloses a P2P information sharing technique for transmitting information for recommending information using evaluation of distribution information in response to a request from a node device. In order to prevent an increase in the load on the network due to a large number of search requests, Patent Document 2 discloses a technique for reducing communication load by rearranging terminals having similar preferences close to each other on the P2P network. Disclosure.

  Furthermore, Patent Document 3 discloses a P2P information search technique that increases the search efficiency by determining the transfer destination of a search request based on the evaluation of a node device.

JP 2007-213332 A JP 2005-115453 A JP 2005-018217 A CLARKE, A distributed decentralized information storage and retrieval system, 1999.http: //citeseer.ist.psu.edu/clarke99distributed.html M. Ripeanu, 2 others, Mapping the gnutella network: Properties of large-scale peer-to-peer systems and implications for system design. IEEE Internet Computing Journal, 6 (1), 2002

The conventional P2P type information retrieval system is intended to retrieve information shared and distributed among nodes, and there are the following problems in the use of retrieving content stored in a server.
First, the content stored in the server changes its state due to deletion or congestion, but when the content state changes, the latest state cannot be reflected in the search result. This is because the index information of the content once generated circulates without changing for a long time and is used for searching.

  Furthermore, there is a problem that the search result of the content cannot be appropriately displayed according to the subjective preference of the user for the content.

  The present invention provides an information search system and a program suitable for a content search system using P2P capable of appropriately evaluating and rearranging content straddling a plurality of server devices searched using evaluation information for content. . In addition, an information search system and program suitable for a content search system using P2P that can reflect the latest state of the content in the search result and can perform different operations depending on the state of the content are provided. Furthermore, an information search system and program suitable for a content search system that can easily reach necessary information from distributed and shared information are provided.

  The above-described problem is that a distribution device that holds content, identification information that indicates the location and content of the content held by the distribution device, and that communicates with each other through a network to search for content based on a predetermined condition. The user terminal further stores individual information composed of content usage information and preference information of the user who acquired the content, and is transmitted and received mutually when searching for the content. Information that updates the usage information and preference information that is held from the information and individual information that is transmitted and received when the content is acquired, and displays the content search results based on the updated usage information and preference information This can be achieved by a search system.

  In addition, the computer includes a storage unit that stores individual information including content usage information and preference information of a user who has acquired the content, a table update unit that updates usage information and preference information based on the received individual information, Based on the updated usage information and preference information, this can be achieved by a program for functioning as a search processing unit that displays a search result of content.

  According to the present invention, content information suitable for a user can be extracted from a large amount of content information searched on a P2P network. Further, the search operation can be changed according to the state of the content. In addition, the search efficiency is improved and the load on the network is reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings using examples. The same reference numerals are assigned to substantially the same parts, and the description will not be repeated.

  The configuration of the content search system will be described with reference to FIG. Here, FIG. 3 is a hardware block diagram illustrating the configuration of the content search system. In FIG. 3, the content distribution system 200 includes a P2P network 100 and two content distribution servers 20.

  The P2P network 100 is composed of four user terminals 10. Here, the user terminal 10-1 is P2P connected to the user terminal 10-2. The user terminal 10-2 is P2P connected to the user terminals 10-1 and 10-3. Similarly, the user terminal 10-3 is P2P connected to the user terminals 10-2 and 10-4. Further, the user terminal 10-4 is P2P connected to the user terminal 10-3.

  Each of the user terminals 10 includes a content individual information storage device 11. Each of the content distribution servers 20 includes a content storage device 21. The content distribution server 20 and the user terminal 10 are connected via a communication network such as the Internet, and communicate as necessary. The user terminals 10 constitute a peer-to-peer network 100 and can communicate with each other. However, direct P2P communication is possible between the user terminal 10-1 and the user terminal 10-2 connected by a solid line, between the user terminal 10-2 and the user terminal 10-3, and between the user terminal 10-3 and the user. It is between the terminal 10-4.

  Each of the content distribution servers 20 holds a content storage device 21 for storing the content. The content distribution server 20 provides content held in the content storage device in response to a content acquisition request from the user terminal 10. In addition, the content distribution server 20 registers content in the content storage device 21 in response to a content registration request from the user terminal 10.

  The content distribution server 20 is embodied by an information processing apparatus that holds communication means. Specifically, the information processing apparatus has an Internet communication function and a Web server function and holds multimedia contents.

  The user terminal 10 registers the content with the content distribution server 20 in order to publish the content, acquires the content from the content distribution server 20, and reproduces the content.

  The content identification information table, content usage information table, and content preference information table will be described with reference to FIG. Here, FIG. 4A is a content identification information table. FIG. 4B is a content usage information table. FIG. 4C is a content preference information table. These tables are held by the content individual information storage device 11 of the user terminal 10.

  In FIG. 4A, the content identification information table 210 stores content identification information. The content identification information table 210 includes a content name (Name) 211, a location identifier (URI) 212 indicating the location where the content exists, a content ID (Content ID) 213 uniquely assigned to the content, and a file type indicating the type of content. (File Type) 214. The content identification information table 210 includes information necessary for acquiring specific content from the content distribution server and content attribute information serving as a search key when searching for content. The content identification information is generated by the content distribution server 20 when the content is registered, and is fixed to a specific content and is not changed.

  In FIG. 4B, the content usage information table 220 stores content usage information. The content usage information table 220 includes a content ID (Content ID) 221 associated with the content identification information table 210, an acquisition count (Play Count) 222 that is a value of the lower bound (Lower Bound) of the number of times content acquisition has been successful, The content is composed of an acquisition failure count (Failed Count) 223 that is a lower limit value of the number of times content acquisition has failed and a last access date / time (Access Time) 224 to the content. The content usage information table 220 includes objective evaluation information when content is acquired from the content distribution server 20.

  When the user terminal 10 tries to acquire the content, the user terminal 10 changes the content usage information held and reflects the content usage information in the content usage information table 220. For this reason, in the different user terminals 10-1 and 10-2, the content usage information included in the content individual information for the same content does not match.

  In FIG.4 (c), the content preference information table 230 hold | maintains content preference information. The content preference information table 230 includes a content ID (Content ID) 231 associated with the content identification information table 210, a preference rate (Favorite Rate) 232 that holds evaluation information for the user's content, and the user who acquired the content. It is comprised from the evaluation score (Critique Rate) 233 holding the average score of evaluation information. The content preference information table 230 holds subjective evaluation information of the user who acquired the content for the content. When the user terminal 10 acquires content, the user terminal 10 changes the content preference information to be held and reflects the content preference information in the content preference information table 230. For this reason, the content usage information held by the different user terminals 10-1 and 10-2 does not match the content preference information 230 even if the corresponding content identification information matches.

  With reference to FIG. 5, the functional block of a user terminal is demonstrated. Here, FIG. 5 is a functional block diagram of the user terminal. In FIG. 5, the user terminal 10 includes a control device 300, an input device 16, an output device 17, and an external storage device 14. In addition, the control device 300 includes a control unit 290, a communication device 15, an input / output interface (I / F) 280, a reception processing unit 260, a transmission processing unit 270, a content identification information table 210, and content usage information. It comprises a table 220, a content preference information table 230, and a P2P connection destination table 240.

  The input device 16 is a mouse, a keyboard, or the like, and transmits a user input to the control device 300. The output device 17 is a display or the like and displays the processing result. The external storage device 14 holds a content database. The external storage device 14 may be included in the control device 300. The control unit 290 controls the entire control device 300. The communication device 15 connects the control device 300 to the other user terminal 10 and the content distribution server 20. The input / output interface (I / F) 280 is an interface with the input device 16, the output device 17, and the external storage device 14. The reception processing unit 260 executes reception processing from the communication device 15. The transmission processing unit 270 executes transmission processing to the communication device 15. The content identification information table 210, the content usage information table 220, and the content preference information table 230 are as described in FIG. The P2P connection destination table 240 holds IP addresses of other user terminals that are P2P connected.

  The control unit 290 is a content registration processing unit that controls content registration processing to the distribution server 20, a content request processing unit that controls content request processing to the distribution server 20, and content transmission / reception that controls content transmission / reception processing with the distribution server 20. A processing unit, an individual information transmission / reception unit that controls transmission / reception of individual information with other user terminals 10, a P2P connection determination processing unit that controls P2P connection and P2P connection disconnection with other user terminals, and content search and ranking It functions as a search processing unit and a table update processing unit that controls the update of each table 210-240.

  The hardware configuration of the user terminal will be described with reference to FIG. Here, FIG. 6 is a hardware block diagram of the user terminal. In FIG. 6, the user terminal 10 includes a central control device 12 connected to the internal communication line 19, a memory 13, an external storage device 14, a communication device 15 connected to the user terminal 10 and the content distribution server 20, It comprises an output device 17 such as a display device and an input device 16 such as a keyboard. The central processing unit 12 executes a program on the memory 13 to realize the functional block of the user terminal 10 described with reference to FIG. The external storage device 14 and the memory 13 constitute a content individual information storage device 11.

  With reference to FIG. 7, content registration processing by the content search system will be described. Here, FIG. 7 is a sequence diagram of a registration process between the two user terminals and the content distribution server. In FIG. 7, the user terminal 10-1 transmits the prepared content to the content distribution server 20 (S101).

  Upon receiving the content transmission, the content distribution server 20 generates a content ID 213 in the content identification information (S102). The content ID 213 avoids duplication of values by calculating a hash of the content using a hash function and adding server-specific information. The content distribution server 20 stores the content and the content ID 213 in the content storage device 11 (S103). The content distribution server 20 transmits the content ID 213 and the location identifier 212 indicating the content storage location to the user terminal 10-1 (S104).

Upon receiving the content ID 213 and the location identifier (URI) 212, the user terminal 10-1 receives input of additional information such as the content name 211 and the file type 214 from the user, and generates content identification information (S106). The content usage information corresponding to the content identification information and the content preference information are generated in the initial state and stored as individual content information (S107). Since the content registered here has never been used, there is no value in some information (last access date 224, preference 232, evaluation score 233) included in the content usage information and content preference information.
Next, the user terminal 10-1 transmits the content individual information to the user terminal 10-2 connected by P2P (S108).

  The content search process will be described with reference to FIG. Here, FIG. 8 is a sequence diagram of search processing between user terminals. In FIG. 8, the user terminal 10-1 includes the content individual information storage device 11 as to whether or not there is content having attribute information that matches attribute information such as the content name and file type input by the user. The content individual information is searched (S111), and the search result is displayed (S112). Furthermore, in order to confirm whether the corresponding information exists in the content individual information held by the other user terminal 10-2, the user terminal 10-1 is connected to the user terminal 10-1 through a P2P network. A content search request is transmitted to 10-2 (S113).

  When the user terminal 10-2 receives the content search request, the user terminal 10-2 searches the content individual information to be held in order to check whether there is content that matches the search request (S114). Here, since the content that matches the search request is hit, the user terminal 10-2 transmits the content individual information to the user terminal 10-1 (S116). The user terminal 10-2 further transfers a content search request to the other connected user terminal 10-3 (S117). Here, by following an algorithm such as limiting the search transfer to a certain number of times, the search request is prevented from being transferred within the P2P network 100 indefinitely.

The user terminal 10-1 that has received the content individual information updates the content individual information (S118), and redisplays the search result (S119).
Receiving the content search request, the user terminal 10-3 searches the content individual information for information that matches the search condition (S121). In this case, since the search is a hit, the user terminal 10-3 transmits the content individual information to the user terminal 10-2 (S122). The user terminal 10-2 that has received the content individual information transfers the content individual information to the user terminal 10-1 (S123).

  The user terminal 10-1 and the user terminal 10-2 that have received the content individual information update the content information, respectively (S124, S126). The user terminal 10-1 displays the search result again (S127) and ends.

  In updating the content individual information (S118, S126), the user terminal 10-1 receives the content individual information searched in the user terminal 10-1 and the content returned from the user terminal 10-2 or 10-3. The content IDs 213 in the content identification information included in the individual information are compared to determine whether the same content individual information exists.

  When it is determined that the content individual information including the content identification information that is not held is received, the user terminal 10-1 receives the content individual information as the content identification information table 210, the content usage information table 220, and the content preference information table 230. Add to In addition, when there is a content identification information overlapping among the search results searched from the received content individual information and the individual information of the user terminal 10-1, the user terminal 10-1 is included in the content individual information. Content usage information and content preference information are integrated based on individual integration rules.

  The integration rules are as follows: (1) For the acquisition count 222 and the acquisition failure count 223 included in the content usage information table 220, the lower bound value of the number of acquisition times of the specific content (at least the value acquired so far) and the lower bound value of the acquisition failure count, respectively. Therefore, in order to be closer to the total number of times that the user terminals 10-1, 10-2, 10-3, and 10-4 have actually acquired the content, the maximum number of acquisition counts 222 and the acquisition failure count 223 is the maximum. Retrieve the value and save it. (2) The last access date and time 224 holds a newer date and time as a new value. (3) Since the evaluation score 233 is the average score of the users who have evaluated the content, the average is taken after weighting with the number of evaluated users. Here, content evaluation is performed at the time of content acquisition, which will be described later. Therefore, the number of users who have evaluated content can be approximated by the acquisition count 222. Therefore, the content individual information evaluation point 233 is weighted by the same individual information acquisition count 222, and a weighted average of the plurality of content individual information evaluation points 233 is acquired and held as a new value. (4) Further, the preference 232 always maintains the value held by the user terminal, and is not updated by the search result.

  Further, in the redisplay of the search results (S119, S127), the user terminal 10-1 displays the content search results in a rearranged order based on a specific algorithm based on various information in the content individual information. Specifically, a value with a large acquisition count 222 is determined to be highly popular content and is displayed at a higher level, and a value with a large acquisition failure count 223 is determined to be lower due to congestion. To display. Also, the newest access date and time 224 is displayed at a higher level. The rearrangement process can also define the priority according to the user's preference.

  In this way, content search results can be processed effectively by using not only summary information fixed for each content but also additional information that is variable depending on the access and evaluation of the content of the user and is different depending on the user. it can. That is, processing such as finding popular content can be performed.

  The content acquisition process will be described with reference to FIG. Here, FIG. 9 is a sequence diagram for explaining content acquisition processing between the three user terminals and the content distribution server. In FIG. 9, the user terminal 10-1 analyzes the location identifier 212 of the acquired content identification information, specifies the logical position of the content distribution server 20-1 and the content, and sends a content acquisition request to the content distribution server 20. -1 is transmitted (S131).

  The content distribution server 20-1 receives the content acquisition request, and reads the content and the content ID from the content storage device 21 (S132). Here, authentication processing and billing processing of the user terminal 10-1 may be performed as necessary. The content distribution server 20-1 transmits the read content and content ID to the user terminal 10-1 (S133).

  The user terminal 10-1 receives the content, compares the content ID received at the same time with the content and the content ID 213 of the content identification information table 210. If they match, the user terminal 10-1 determines that the content is correct and reproduces the content (S134). A dedicated player for playing video files and music files may be used for playing the content.

  When acquiring the content, the user terminal 10-1 updates the held content usage information table 220 according to the acquisition result (S136). Specifically, when the content acquisition is successful, the user terminal 10-1 increments the acquisition count 222 corresponding to the content in the content usage information table 220 by 1, and updates the last access date 224 to the current time. . When the content acquisition fails, the user terminal 10-1 increases the acquisition failure count 223 by one.

  In addition, the user terminal 10-1 updates information corresponding to the corresponding content in the content preference information table 230 to be held according to the user's input. Specifically, the user terminal 10-1 sets a value representing the evaluation for the content acquired by the user in the preference 232 of the content preference information table 230. Furthermore, since the evaluation score 233 is an average of the evaluations of all users of the content, the user terminal 10-1 updates based on the set favorability 232. The user terminal 10-1 approximates the total number of users of the content by the acquisition count 222, weights the evaluation score 233, calculates a weighted average with the favorableness 232, and updates the evaluation score 233.

  Next, the user terminal 10-1 transmits the updated entry in the content individual information to the connected user terminal 10-2 (S137). The other user terminal 10-2 that has received the content individual information updates the content individual information to be held (S138), and transfers the received content individual information to the user terminal 10-3 (S139). In this way, the update information of the content individual information is transmitted, but this also sets a limit on the number of transfer times to prevent unlimited transmission.

  In this way, when the content is acquired, the information updated according to the state of the content is transmitted to other user terminals, so that the latest information on the content can be transmitted and appropriate action can be taken. In FIG. 9, the update of the individual content information of the user terminal 10-3 is omitted in order to avoid complexity.

  The user terminals 10-1 to 10-4 configuring the peer-to-peer network 100 share the content individual information to be held, and change the configuration of the peer-to-peer network based on the shared information. This network reconfiguration process will be described with reference to FIG. Here, FIG. 10 is a sequence diagram illustrating network reconfiguration processing between user terminals.

  In FIG. 10, the user terminal 10-2 transmits content individual information to the user terminal 10-3 when content acquisition is performed and when a content search request is received from the user terminal 10-3 (S151).

  The user terminal 10-3 that has received the content individual information updates the content individual information (S152), and determines whether or not to continue the connection based on the content preference information (S153). At this time, the user terminal 10-1 transmits the content individual information to the user terminal 10-2 (S156). The user terminal 10-2 that has received the content individual information transfers the content individual information of the user terminal 10-1 to the user terminal 10-3 (S157).

  The user terminal 10-3 that has received the content individual information updates the content individual information (S158), and determines whether or not to start a connection based on the content preference information (S159). Since the determination in step 153 is “No”, the user terminal 10-3 transmits disconnection to the user terminal 10-2 (S160). Since the connection start necessity determination in step 158 is “necessary”, the user terminal 10-3 transmits the start of a new connection to the user terminal 10-1 (S161) and ends.

  According to this embodiment, the network is rearranged so that user terminals that are close to each other are logically close to each other, the search efficiency is increased, and the network load can be reduced. Moreover, the reliability of the evaluation point 233 is increased by gathering evaluations of users who are close to each other.

  With reference to FIG. 11, the content registration process of a user terminal is demonstrated. Here, FIG. 11 is a flowchart of the content registration processing of the user terminal. The user terminal 10 transmits the content, content name, and file type to the content distribution server 20 and registers the content (S201). The user terminal 10 determines whether the registration is successful (S202). When the result is No, the user terminal 10 ends, and when the result is Yes, the user terminal 10 adds the content ID and URI returned from the content distribution server 20 to generate content identification information (S203). The user terminal 10 generates content individual information from the content identification information, and sets initial values for the content usage information and the content preference information (S204). The user terminal 10 determines whether there is another connected user terminal (S206). When the result is No, the user terminal 10 ends. When the result is Yes, the user terminal 10 transmits the content individual information to another connected user terminal (S207), and the process ends.

  With reference to FIG. 12, the content search process of a user terminal is demonstrated. Here, FIG. 12 is a flowchart of the content search process of the user terminal. In FIG. 12, when the user terminal 10 receives a content search condition from the user (S211), the user terminal 10 compares the stored content individual information with the search condition (S212). The user terminal 10 determines whether it matches the search condition (S213). In the case of Yes, the user terminal 10 rearranges the matched list of content individual information based on the content usage information and the content preference information, and displays it as a search result (S214). Next, the user terminal 10 determines whether there is another connected terminal 10 (S216). When No in step 213, the user terminal 10 jumps to step 214 and transitions to step 216.

  When Yes in step 216, the user terminal 10 transmits a search request to the other connected terminal 10 (S217). The user terminal 10 receives the content individual information from the other terminal 10 as a search request response (S218). The user terminal 10 compares the received content individual information with the content identification information of the content identification information held (S219). The user terminal 10 determines whether the identification information is the same (S221). In the case of Yes, the user terminal 10 updates the content usage information and the content preference information of the content individual information (S222), updates the content search result by adding a response from another terminal (S223), and ends.

  When No in step 216, the user terminal 10 ends as it is. When No in step 221, the user terminal 10 adds the received content individual information to the content individual information table (S 224), and transitions to step 223.

  With reference to FIG. 13, the content search and transfer process of the user terminal will be described. Here, FIG. 13 is a flowchart of the content search and transfer process of the user terminal. In FIG. 13, the user terminal 10 receives a content search request from the connected terminal (S231), and searches for individual content information to be held (S232). The user terminal 10 determines whether the search condition is met (S233). When they match (Yes). The user terminal 10 responds to the terminal that made the search request as a search result with the matched content individual information (S234), and compares the transfer count of the search request with the transfer upper limit value (S236). When they do not match in step 233 (No), the user terminal 10 jumps to step 234 and transitions to step 236.

  The user terminal 10 determines whether it is below the upper limit (S237). When the result is Yes, the user terminal 10 determines whether there is another connection terminal (S238). In the case of Yes, the user terminal 10 adds 1 to the transfer count of the search request (S239), transfers the search request to the other connection terminal (S241), and ends. When step 237 or step 238 is No, the user terminal 10 ends the process.

  With reference to FIG. 14, the content acquisition process of a user terminal is demonstrated. Here, FIG. 14 is a flowchart of the content acquisition process of the user terminal. In FIG. 14, the user terminal 10 transmits a content acquisition request to the content distribution server 20 based on the content identification information (S251). The user terminal 10 determines whether the content acquisition is successful (S252). In the case of Yes, the user terminal 10 adds 1 to the Play Count 222 of the content usage information and updates it (S253), and updates the Access Time 224 of the content usage information to the current date and time (S254).

  The user terminal 10 reproduces the content (S256) and asks the user to evaluate the content (S257). The user terminal 10 determines whether or not a user evaluation has been input (S258). In the case of Yes, the Favorite Rate 232 of the content preference information is updated by user evaluation, and the Critical Rate 233 is updated based on the Favorite Rate 232 and the Play Count 222 (S259). The user terminal 10 determines whether there is another connected terminal (S261). When No in step 252, the user terminal 10 updates the content usage information Failed Count 223 by adding 1 (S 262), and transitions to step 261. Further, when No in step 258, the user terminal 10 directly proceeds to step 261.

  When Yes in step 261, the user terminal 10 transmits the updated content individual information to the other connected user terminal (S263), and ends. When No in step 261, the user terminal 10 ends as it is.

  With reference to FIG. 15, the network reconfiguration process of the user terminal will be described. Here, FIG. 15 is a flowchart of network reconfiguration processing of the user terminal. In FIG. 15, the user terminal 10 receives content individual information from another connected user terminal (S <b> 271). The user terminal 10 determines whether the reception of the content individual information is a response to the transmission of the content search request (S272). When No, the user terminal 10 determines whether there is a connection terminal (S273). In the case of Yes, the user terminal 10 transfers the content individual information to the third user terminal being connected (S274). The user terminal 10 compares the received content individual information with the held content individual information (S276). When the result in Step 272 is Yes, the user terminal 10 transfers the individual content information responded to the requesting user terminal (S277), and proceeds to Step 276. When No in step 273, the user terminal 10 directly proceeds to step 276.

The user terminal 10 determines whether there is the same identification information (S278). When Yes, the user terminal 10 updates the content usage information and the content preference information of the content individual information (S281). The user terminal 10 compares the Favorite Rate Favorite Rate 232 (S282). The user terminal 10 determines whether the value is close (S283). If Yes, it is determined whether or not the content individual information received in step 271 is directly connected to the user terminal of the transmission source (S284). When No, the user terminal 10 starts direct connection with the user terminal that is the source of the content individual information (S286), and ends. When No in step 278, the user terminal 10 adds the content individual information received in step 271 as new information to the content individual information table (S279), and ends. When No in step 283, the user terminal 10 determines whether it is directly connected to the user terminal that is the source of the content individual information received in step 271 (S287). Is terminated (S288) and the process ends.
The determination of the close value in step 283 may be an absolute value (4 or more) or a relative value (within the user's best 5).

  A specific reconfiguration process of the P2P network will be described with reference to FIGS. 16 and 17. Here, FIG. 16 is a diagram for explaining the disconnection of the P2P connection. FIG. 17 is a diagram for explaining the start of a new P2P connection. The step numbers in FIGS. 16 and 17 are based on FIG.

  In FIG. 16, the user terminal 10-2 holds a content preference information table 230-2, and the user terminal 10-3 holds a content preference information table 230-3. In FIG. 16, information (evaluation point 233) that is not necessary for this processing in the content preference information is omitted in order to avoid complexity. The user terminal 10-3 transmits the content individual information including the preference information of the Content ID aaaaaa to the user terminal 10-2 (S151). The user terminal 10-2 that received the content individual information compares the Favorite Rate Favorite Rate 232 of the content ID aaaaaa held with the preference information Favorite Rate 232 of the received content individual information, and compares the user terminal 10-3 with the user terminal 10-3. Judge that the taste does not suit. As a result, the user terminal 10-2 disconnects the existing connection with the user terminal 10-3 (S160).

  In FIG. 17, the user terminal 10-2 holds a content preference information table 230-2, the user terminal 10-3 holds a content preference information table 230-3, and the user terminal 10-1 holds content preference information. The table 230-1 is held. In FIG. 17, information (evaluation point 233) that is not necessary for this processing in the content preference information is omitted in order to avoid complexity.

  The user terminal 10-1 transmits content individual information including the preference information of Content ID aaaaaa to the user terminal 10-3 (S156). The user terminal 10-3 that has received the content individual information transfers the received content individual information to the user terminal 10-2 (S157). The user terminal 10-2 that has received the content individual information compares the Favorite Rate Favorite Rate 232 of the content ID aaaaaa held with the preference information Favorite Rate 232 of the received content individual information, and compares the user terminal 10-1 It is judged that the taste is suitable. As a result, the user terminal 10-2 starts a new connection connection with the user terminal 10-1 (S161).

  According to the embodiment described above, content information suitable for the user can be extracted from a large amount of content information searched on the P2P network. In addition, since the change in the state of the content can be notified by the additional information, the search operation can be changed according to the state of the content. Furthermore, since the network is rearranged so that users with similar preferences are approached, there is an effect that search efficiency is improved and the load on the network is reduced.

It is a block diagram explaining a peer-to-peer network. It is a flowchart explaining the joining procedure to a peer-to-peer network. It is a hardware block diagram explaining the structure of a content search system. It is a figure explaining a content identification information table, a content utilization information table, and a content preference information table. It is a functional block diagram of a user terminal. It is a hardware block diagram of a user terminal. It is a sequence diagram of a registration process between two user terminals and a content distribution server. It is a sequence diagram of the search process between user terminals. It is a sequence diagram explaining the content acquisition process between two user terminals and a content delivery server. It is a sequence diagram explaining the network reconfiguration process between user terminals. It is a flowchart of the content registration process of a user terminal. It is a flowchart of the content search process of a user terminal. It is a flowchart of the content search transfer process of a user terminal. It is a flowchart of the content acquisition process of a user terminal. It is a flowchart of the network reconfiguration process of a user terminal. It is a figure explaining the cutting | disconnection of P2P connection. It is a figure explaining the start of new P2P connection.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... User terminal, 11 ... Content individual information storage device, 12 ... Central control device, 13 ... Memory, 14 ... External storage device, 15 ... Communication device, 16 ... Input device, 17 ... Output device, 19 ... Internal communication line, DESCRIPTION OF SYMBOLS 20 ... Content delivery server, 21 ... Content storage apparatus, 100 ... Peer-to-peer network, 200 ... Content delivery system, 210 ... Content identification information table, 220 ... Content use information table, 230 ... Content preference information table, 240 ... P2P connection destination table , 260 ... reception processing unit, 270 ... transmission processing unit, 280 ... input / output I / F, 290 ... control unit, 300 ... control device.

Claims (4)

A plurality of users who hold content and a user who holds identification information indicating the location and content of the content held by the distribution device, and searches for content based on a predetermined condition by communicating with each other through a network In an information retrieval system consisting of terminals,
The user terminal further accumulates individual information consisting of content usage information and preference information of the user who acquired the content, and when acquiring the individual information and content that are transmitted and received with each other when searching for the content The usage information and the preference information to be held are updated from the individual information transmitted / received to / from each other, and a content search result is displayed based on the updated usage information and the preference information. Information retrieval system. The information search system according to claim 1,
The information retrieval system, wherein the usage information includes a success count and a failure count of a content acquisition request. The information search system according to claim 1 or 2,
The user terminal compares the preference information when the individual information is transmitted / received to / from other user terminals, and logically approaches user terminals having similar preference information. An information retrieval system characterized by reconfiguring a network. Computer
An individual information storage unit comprising content usage information and preference information of the user who acquired the content,
A table updating unit for updating the usage information and the preference information based on the received individual information;
A search processing unit for displaying a content search result based on the updated usage information and preference information;
Program to function as.

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