Keita Sugihara, Nanzan
Keita Sugihara graduated from Osaka University, Japan, with an engineering degree. He
holds Masterʼs degree and Ph. D. in arts and sciences from Nagoya University, Japan.
Previously, he has worked as a Postdoctoral Research Fellow of Japan Society for the
Promotion of Science (JSPS). Currently, he is working as an Assistant Professor in the
Faculty of Science and Engineering at Nanzan University. His research interests
include algorithms for ranking the nodes in a
graph and social network analysis. He holds an
internationally pending patent for an algorithm
related internet search engines and this patent
has been established in Japan. Dr. Sugihara is a
member of Information Processing Society of
Japan (IPSJ), Japanese Society for Engineering
Education (JSEE), Institute of Electrical and
Electronics Engineers (IEEE), Association for
Computing Machinery (ACM) and International
Network for Social Network Analysis (INSNA).
Speech Title: Beyond Google's PageRank: Using Complex Numbers in Node Ranking Calculations
Abstract: The first part of this presentation introduces web information retrieval and Google’s PageRank. This part of the talk focuses on how PageRank determines the score of a website on the Internet on the basis of its hyperlink relations. Furthermore, the characteristics of Google’s widely used algorithm and the problems associated with PageRank are emphasized.
The second part of the talk covers basic graph theory to introduce the Hermitian centrality score, which is immune to the problems experienced by PageRank. The proposed algorithm uses complex numbers and the complex plane to calculate the score of a site. This algorithm can reproduce the ranking results of PageRank well, and the Hermitian centrality score can systematically change the score of a site.