Apparatus for retrieving and presenting digital data

1. An apparatus for retrieving and presenting digital data, comprising:

a network that includes plural data archives each containing a plurality of multimedia digital data;

a terminal configured to be connected to the network;

a database of digital data retrieval information comprising predetermined item information added to each of digital data that can be presented over the network;

retrieval unit configured to retrieve digital data corresponding to retrieval conditions based on item information specified by a keyword input by a terminal user, using the database, and extracts the retrieved digital data;

communication quality determination unit configured to measure a throughput in bits per second of a network path from a data archive containing the retrieved digital data to the terminal, divide a volume of the extracted digital data by the throughput to calculate a time it takes to download each of the extracted digital data from the data archive to the terminal and to generate scores in order from a low end of values calculated relative to the individual extracted digital data, thereby determining communication quality of the extracted digital data; and

information presentation unit configured to present the extracted digital data in an order in accordance with a priority specified by the user, based on a matching property with the item information and on the communication quality.

2. An apparatus for retrieving and presenting digital data according to claim 1 , wherein the information presentation unit beforehand stores therein information on classes of digital data that can be handled by the terminal, filters out digital data that cannot be handled by the terminal from the digital data extracted presented in the order, and presents the digital data having the digital data filtered out in an order in accordance with a priority specified by the user.

3. An apparatus for retrieving and presenting digital data according to claim 1 , wherein the information presentation unit is configured to present the extracted digital data in an order by a procedure comprising:

using scores n k prepared in order from a high end of matching property based on a matching standard relative to item information specified by the terminal user with respect to each of digital data m jk extracted by the retrieval unit, in which m jk means a k-th data m in a j-th archive, and j and k are natural numbers, respectively, and using scores n q prepared through division of a volume of each digital data m jk by a throughput Th j from the j-th data archive containing the extracted digital data m jk to the terminal to calculate a time it takes to download each of the extracted digital data from the archive containing the extracted digital data to the terminal, thereby enabling the scores to have score numbers in order from a low end of values calculated; and

obtaining values from formula w k n k +w q n q with respect to a level of importance w q of the communication quality and a level of importance w k of the item information, wherein 0≦w k , w q ≦100 and w k +w q =100, to present the digital data m jk in order from a high end of the obtained values.

4. An apparatus for retrieving and presenting digital data according to claim 1 , wherein the multimedia digital data include text, voice, still images and video.