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


PhD Thesis Defence


"On Processing Spatial Queries in Mobile Client/Server
Environments"

By

Miss Manli Zhu


Abstract

With the advent of wireless communication, portable computing and location
sensing technologies, location-based data-intensive applications have been
developed in various areas. Location-based applications make use of
location information to support spatial queries (e.g., finding the nearest
hotel for a user or displaying all restaurants in the geographic area
around him). In this thesis, we study the processing of spatial queries in
mobile environments, where users can issue spatial queries to the server
while they are moving. Due to the mobility of users, the server must have
the ability not only to produce results that are valid with respect to
their current locations but to update the results as the users move to new
locations. Coupled with the large number of users anticipated in mobile
environments, the server must be able to handle high workload and as such
needs efficient query processing methods. Considering the uniqueness of
mobile client/server environments, this thesis i) studies the region in
which the user can move without affecting the result of a window query and
thus reduce the communication cost for checking the result validity on the
server, ii) introduces the top-k spatial join and proposes an efficient
query processing algorithm for it, iii) studies the problem of continuous
monitoring k-closest pair query over moving objects, aiming at reducing
the communication cost and speeding up the monitoring process, and iv)
discusses the real-time parallel processing of window queries on spatial
databases.


Date:			Wednesday, 26 January 2005

Time:			3:00p.m.-5:00p.m.

Venue:			Room 3006
			Lift 3

Chairman:		Prof Sudipto Dasgupta (FINA)

Committee Members: 	Prof. Dik-Lun Lee (Supervisor)
		   	Prof. Frederick Lochovsky
		   	Prof. Dimitrios Papadias
		   	Prof. David Bodoff (ISMT)
		   	Prof. Kian-Lee Tan (Comp. Sci.,
					    National Univ. of Singapore)


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