Research topics

• Search technology for efficient retrieval of useful information from a huge data space
• Data mining technology to extract interesting rules from huge volumes of data
• Data visualization techniques to visualize huge volumes of data intelligibly
• Advanced database/storage management mechanisms to manage huge volumes of data

Very Large scale web solutions

The Web has become a very important source of information, and is accumulating vass amounts of information. We have been collecting and archiving all the web pages of Japan for over 5 years. We are developing a Web Warehouse as well as various tools to detect its spatial properties and time-series behavior.

Our research includes extracting cybercommunities through analysis of link structures on the web, extracting global user behavior patterns by mining web access logs, and ultrahigh-speed crawling. We are also pursuing content-mining which adds new values by synthesizing information collected from the web with information from other domains.

Web Structure Mining

• Web Community Chart
• Max flow algorithm based Cyber Community Extraction
• Search Results Clustering

Web Contents Mining

• Location Based Search

Web Log Mining

• Access Log Analysis and Visualization

Large scale storage solutions

Today, with the progress of data-mining technology, information is becoming to be considered as an asset, and the role of storage in computer systems has increased remarkably. Also, higher reliablility for data-retention and advanced management mechanisms for huge volumes of data are demanded.

Especially after 9.11, the U.S. SEC has made a policy statement for business continuity, and highly reliable storage systems are strongly demanded as a social infrastructure.

By integrating database technology and storage technology we are developing next generation high-performance storage systems. This is realized by combining highly reliable, fast recovery storage and upper application layer's knowledge.

• SAN-connected PC cluster
• Autonomic DBMS
• iSCSI

Petabyte-class global environment digital library

We are constructing a digital library of global environment information such as satellite data. Our research includes large scale data archiving, metadata management, and grid computing.

• Data Archive
• Visualization/Mining

Core database technologies

Databases have evolved from an static system which stores information to a system which manages information that changes in real time, and provides information in close coordination with applications. We are developing new core technologies to match these usage changes.

• Spatial P2P and GRIDs
• Publish/Subscribe