テイレベルヘイレツショリケイサンキQA-1ノカイハツ

京都大学0048新制・課程博士工学博士甲第2295号工博第635号新制||工||455(附属図書館)6185UT51-54-X31京都大学大学院工学研究科数理工学専攻(主査)教授 萩原 宏, 教授 津田 孝夫, 教授 長谷川 利治学位規則第5条第1項該当Kyoto UniversityDA

Application of matrix clustering to web log analysis and access prediction

Matrix clustering is a new data mining method which extracts a dense sub-matrix from a large sparse binary matrix. We propose an e cient algorithm named the ping-pong algorithm which enables real-time mining of a large sparse matrix. This article describes the application of matrix clustering to Web usage mining. Matrix clustering can be applied to Web access log analysis by representing relationships between pages and users in a binary matrix. An experiment with a practical WWW access log shows that page clusters can be extracted by applying matrix clustering. The extracted page clusters are compared with those obtained by association rule mining. The result shows that matrix clustering is more powerful in nding various types of page clusters. The page clusters extracted by matrix clustering can be applied to web access prediction. We have also compared the matrix clustering with association rule mining and sequence pattern mining with respect to access prediction. The result shows that matrix clustering has a higher hit rate than these methods when the session length is long.

Report on the survey of freshwater planarians and the water analysis in the Suyoshi River,

The Suyoshi River is a first-class river running from Suyoshi, the eastern hill side of Nagaoka city through the central aerea of the city to join the Shinano-gawa River. The creature having correlationship with the emvironmental factor such as water qualities are known as indicator organizms. Planarian is one of the indicator organisms in freshwater emvironment. This paper reports the survey about the distribution of aquatic indicator organizms, mainly planarians and the water qualities in the Suyoshi River. Cl-, Na+, K+ and Ca2+ at downstream sampling sites were higher than at upstream sites. NO3 -N was 0.19mg/L at sampling site No.4. Three spieces of freshwater planarians; Phagocata vivida, Dugesia japonica and Girardia tigrina were found in the Suyoshi River by different distribution. G. tigrina is the first foreign planarian spieces reported in Niigata Prefecture. This survey was conducted with pre-laboratorial (Prelab) students during May to October in 2016