For many applications of location-based services, such as friend finding, buddy tracking,information sharing and cooperative caching in ad hoc networks, it is often important to be able to identify whether the positions of a given set of moving objects are within close proximity. To compute these kinds of proximity relations among large populations of moving objects, continuously available location position information of these objects must be correlated against each other to identify whether a given set of objects are in the specified proximity relation. In this dissertation, we state this problem, referring to it as the location constraint matching problem, both in the Euclidean space and the road network space. In the Euclidean space, we present an adaptive solution to this problem for various environments. We also study the position uncertainty associated with the constraint matching. For the road network space, where the object can only move along the edges of the road network, we propose an efficient algorithm based on graph partitioning, which dramatically restricts the search space and enhances performance. Our approaches reduce the constraint processing time by 80% for Euclidean space and by 90% for road network space respectively. The logical combination of individual constraints with conjunction, disjunction and negation results in more expressive constraint expressions than are possible based on single constraints. We model constraint expressions with Binary Decision Diagrams (BDD). Furthermore, we exploit the shared execution of constraint combinations based on the BDD modeling. All the algorithms for various aspects of the constraint processing are integrated in the research prototype L-ToPSS (Location-based Toronto Publish/Subscribe System). Through experimental study and the development of an analytical model, we show that the proposed solution scales to large numbers of constraints and large numbers of moving objects.

For many applications of location-based services, such as friend finding, buddy tracking,information sharing and cooperative caching in ad hoc networks, it is often important to be able to identify whether the positions of a given set of moving objects are within close proximity. To compute these kinds of proximity relations among large populations of moving objects, continuously available location position information of these objects must be correlated against each other to identify whether a given set of objects are in the specified proximity relation. In this dissertation, we state this problem, referring to it as the location constraint matching problem, both in the Euclidean space and the road network space. In the Euclidean space, we present an adaptive solution to this problem for various environments. We also study the position uncertainty associated with the constraint matching. For the road network space, where the object can only move along the edges of the road network, we propose an efficient algorithm based on graph partitioning, which dramatically restricts the search space and enhances performance. Our approaches reduce the constraint processing time by 80% for Euclidean space and by 90% for road network space respectively. The logical combination of individual constraints with conjunction, disjunction and negation results in more expressive constraint expressions than are possible based on single constraints. We model constraint expressions with Binary Decision Diagrams (BDD). Furthermore, we exploit the shared execution of constraint combinations based on the BDD modeling. All the algorithms for various aspects of the constraint processing are integrated in the research prototype L-ToPSS (Location-based Toronto Publish/Subscribe System). Through experimental study and the development of an analytical model, we show that the proposed solution scales to large numbers of constraints and large numbers of moving objects.

Ce travail est consacré à l'analyse des outils et méthodes de prévention et de pilotage des conflits d'usage dans les pays en voie de développement, et plus particulièrement à l'étude des conflits liés à l'installation de nouvelles infrastructures, qui ont provoqué l'expropriation d'habitations et d'exploitations agricoles ainsi que la disparition de nombreuses ressources productives dans les espaces ruraux. L'étude se fonde sur le cas du barrage de Chotiari, au Pakistan, avec une analyse de l'impact du projet sur les ressources naturelles et socio-économiques de la région, ainsi que des racines de ce conflit. Une attention particulière est accordée au réseau d'acteurs utilisateurs de l'espace, ainsi qu'à la violation des droits de propriété, qui a provoqué des asymétries de pouvoir et conduit à la montée des conflits d'usage de l'espace. Notre recherche montre que les conflits résultant du lancement de ce projet résultent de causes structurelles (tels que des décisions unilatérales, l'absence d'études et d'expertises scientifiques et techniques, la corruption, l'importance d'intérêt internationaux et l'absence de politique nationale d'intégration) comme de facteurs plus locaux (comme le népotisme, la diversité ethnique et l'illettrisme). Par ailleurs, les déplacements forcés de populations locales ont conduit à une multiplication des oppositions et des confrontations. Pour finir nous tirons de ces résultats un certain nombre de recommandations en termes de prévention et de pilotage des conflits, fondées sur la mobilisation des relations de proximité. / This research discusses the tools of land use conflict analysis and methods for their prevention and management, on the basis of existing conflicts created by infrastructural projects in developing countries. Such conflicts have entailed expropriation of homes, farm businesses and other productive resources in rural settings. Specifically, we use data from the case of Chotiari water reservoir project in Pakistan, where we put stress on project impacts on socio-economic and natural resource values in the region, by highlighting root causes of the conflicts with response to land use decision. We also paid attention on the network of actors over land use and property right violation, which have created dissimilar power distribution and significant land use conflicts. Through this research we show that conflicts created by the project have resulted from structural factors (unilateral decision, lack of technical and scientific investigation, corruption, international interest, and non-existence of national resettlement policy) and proximate factors (nepotism, ethnic diversity/disarray, and illiteracy). Moreover, forceful displacement of local population has led for multiplication of the confrontations. From these results, we provide helpful insights and information for the recommendations in terms of land use conflict prevention and management, mainly based on proximity relations analysis.