The Hong Kong University of Science and Technology
Department of Computer Science and Engineering


PhD Thesis Defence


"Full-Text Keyword Search in Meta-search and P2P Networks"

By

Miss Jing Zhao


Abstract

Due to the information growth, distributed systems, such as peer-to-peer
(P2P) systems or meta-search systems, have become a popular and to some
extent revolutionary solution to large-scale data sharing. They offer
advantages such as autonomy, flexibility for peers to join and leave the
system freely, scalability without the need of powerful and expensive
processors, and robustness against single-peer failures. However, the
"open nature" of P2P systems and their lack of centralized control pose
difficult challenges to full-text search, which can be implemented in
centralized systems with powerful search ability and high precision.

We study keyword query methods in meta-search and P2P networks. For
meta-search, we propose server ranking approaches in which each search
engine's document collection is divided into clusters based on the index
terms. Furthermore, we keep the term correlation information in a cluster
descriptor to improve the server ranking quality. For P2P networks, we
propose an efficient and scalable technique to support partial-match
queries. A distributed index structure, called the distributed pattern
tree (DPTree), is used to record frequent query patterns, i.e.,
combinations of keywords, learnt from the query history at each node in
the network. Using this index, a query can identify its best matching
patterns quickly and data lookup can be done in logarithmic time with
respect to the network size.


Date:			Friday, 19 January 2007

Time:			10:00a.m.-12:00noon

Venue:			Room 3501
			Lifts 25-26

Chairman:		Prof. Inchi Hu (ISMT)

Committee Members:	Prof. Dik Lun Lee (Supervisor)
		  	Prof. Qiong Luo (Supervisor)
		  	Prof. Frederick Lochovsky
			Prof. Wilfred Ng
			Prof. Danny Tsang (ECE)
			Prof. Wang-Chien Lee (Comp. Sci. & Engg.,
    					     The Pennsylvania State Univ.)


**** ALL are Welcome ****