ON BOOSTING SPATIAL COMPUTATIONS FOR LOCATION-BASED SERVICES

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


PhD Thesis Defence


Title: "ON BOOSTING SPATIAL COMPUTATIONS FOR LOCATION-BASED SERVICES"

By

Mr. Cheng LONG


Abstract

Nowadays, location-based services (LBSs), which refer to those services that 
are based on location (or spatial) data, are broadly used in our daily life. 
Some popular types of LBS include “search-nearby” which searches objects (e.g., 
restaurants, hotels and shops) near a location, “spatial crowdsourcing” which 
allows people to post tasks to be performed at a location (these people are 
called “requesters”) and people to pick some tasks to perform (these people are 
called “workers”), and “trace tracking” which records the trace of a movement 
(e.g., the moving trace of a hiker). Each type of LBS usually relies on some 
computation based on spatial data (which is termed as spa- tial computation). 
For example, the “search-nearby” service relies on spatial keyword query to 
find all objects that are near a given query location and contain a given query 
keyword, the “spatial crowdsourcing” service relies on spatial matching to 
match between tasks and workers, and the “trace tracking” service relies on 
trajectory data management.

In this thesis, we introduce three techniques for boosting the spatial 
computations that are central to LBSs, namely the collective spatial keyword 
query which is one type of spatial keyword query and finds a set of spatial 
objects that cover all the given query keywords and have the smallest distance 
from the query location, worst-case optimized spatial matching which matches 
two sets of spatial objects with the smallest worst-case cost, and 
direction-preserving trajectory which simplifies the trajectory while 
preserving the direction information embedded in the trajectory data.


Date:			Tuesday, 23 June 2015

Time:			3:00pm - 5:00pm

Venue:			Room 2132A
 			Lift 19

Chairman:		Prof. Zhigang Li (MAE)

Committee Members:	Prof. Raymond Wong (Supervisor)
 			Prof. Wilfred Ng
 			Prof. Dimitris Papadias
 			Prof. Xueqing Zhang (CIVL)
 			Prof. Mohamed Mokbel (Univ. of Minnesota)


**** ALL are Welcome ****