This paper discusses the role of granularity in judgments about spatio-temporal location and relations. It distinguishes three aspects of spatio-temporal granularity: the granularity with which location is approximated, the granularity which arises as a function of the degree to which we recognize or trace over changes of location, and granularity as it affects our apprehension of spatio-tempor...

In this paper we address the issue of locating hierarchical facilities in the presence of congestion. Two hierarchical models are presented, where lower level servers attend requests first, and then, some of the served customers are referred to higher level servers. In the first model, the objective is to find the minimum number of servers and their locations that will cover a given region with...

We propose several methods to speed up the facility location, and the single link and the complete link clustering algorithms. The local search algorithm for the facility location is accelerated by introducing several space partitioning methods and a parallelisation on the CPU of a standard desktop computer. The influence of the cluster size on the speedup is documented. The paper further prese...

An efficient stateless routing is possible because geographical routing protocol has many advantages of location information in mobile Ad-Hoc networks (MANETs). Such routing protocol, however, is significantly dependent on the existence of scalable location management services. In this paper, we propose a hierarchical location management (HLF) scheme considering the population of mobile nodes b...

Services for locating mobile objects are often organized as a distributed search tree. The advantage of this approach is that the service can scale as a system grows in size and number of objects. However, a potential problem is that high-level nodes may become a bottleneck affecting the scalability of the service. A traditional solution is to also distribute the location information managed by...

In this paper, we propose a novel approach to expand queries by exploring both location information and topic information of the queries. Users at different locations tend to have different vocabularies, while the different expressions coming from different vocabularies may relate to the same topics. Thus these expressions are identified as location sensitive and can be used for query expansion...

IP mobility can be handled at different layers of the protocol stack. Mobile IP has been developed to handle mobility of Internet hosts at the network layer. As an alternative solution, a number of transport layer mobility protocols have been proposed, for example, MSOCKS and TCP connection migration solution in the context of TCP, and M-SCTP and mobile SCTP in the context of SCTP. More recentl...

An important issue in the design of a mobile computing system is how to manage the location information of mobile clients. In the existing commercial cellular mobile computing systems, a twotier architecture is adopted (Mouly and Pautet, 1992). However, the two-tier architecture is not scalable. In the literatures (Pitoura and Samaras, 2001; Pitoura and Fudos, 1998), a hierarchical database str...