PhD Thesis Proposal Defence


"Supporting Mobile Clients with Spatial and Continuous Spatial Queries"

By Mr. Haibo Hu


Abstract:

Answering (continuous) spatial queries is a fundamental service in
real-life mobile systems. Though indexing and query processing techniques have
been extensively studied for spatial database systems (SDBMS), little
research has been conducted at the client side. In this proposal, we solve some
fundamental problems in supporting these thin-clients for evaluating and
monitoring spatial and continuous spatial queries. Mobile devices have
scarce battery power, low wireless bandwidth, vulnerable network
connectivity, and error-prone location sensors, and above all, they are
in large scale and moving continuously. In light of these constraints, we
tackle three problems in particular: location imprecision, query caching
and location update. More specifically, we propose:
(1) the range nearest neighbor (RNN) query as a generalization of
traditional point nearest neighbor (PNN) queries, where the query input
is approximated by a range; (2) an innovative "proactive caching" model
that supports all types of spatial queries and efficiently reuses the cache
at the object level; (3) a generic framework to monitor continuous spatial
queries with a query-aware update scheme for the mobile clients. All
these techniques effectively reduce CPU, storage and communication cost of the
clients for spatial query processing.


Date:     		Tuesday, 25 January 2005

Time:                   2:00p.m.-4:00p.m.

Venue:                  Room 2504
			lifts 25-26

Committee Members:      Prof. Dik-Lun Lee (Supervisor)
                        Dr. Dimitris Papadias (Chairperson)
			Dr. Qiong Luo
			Prof. Lionel Ni


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