Monitoring using Heterogeneous Autonomous Agents.

This dissertation studies problems involving different types of autonomous agents observing objects of interests in an area. Three types of agents are considered: mobile agents, stationary agents, and marsupial agents, i.e., agents capable of deploying other agents or being deployed themselves. Objects can be mobile or stationary. The problem of a mobile agent without fuel constraints revisiting stationary objects is formulated. Visits to objects are dictated by revisit deadlines, i.e., the maximum time that can elapse between two visits to the same object. The problem is shown to be NP-complete and heuristics are provided to generate paths for the agent. Almost periodic paths are proven to exist. The efficacy of the heuristics is shown through simulation. A variant of the problem where the agent has a finite fuel capacity and purchases fuel is treated. Almost periodic solutions to this problem are also shown to exist and an algorithm to compute the minimal cost path is provided. A problem where mobile and stationary agents cooperate to track a mobile object is formulated, shown to be NP-hard, and a heuristic is given to compute paths for the mobile agents. Optimal configurations for the stationary agents are then studied. Several methods are provided to optimally place the stationary agents; these methods are the maximization of Fisher information, the minimization of the probability of misclassification, and the minimization of the penalty incurred by the placement. A method to compute optimal revisit deadlines for the stationary agents is given. The placement methods are compared and their effectiveness shown using numerical results. The problem of two marsupial agents, one carrier and one passenger, performing a general monitoring task using a constrained optimization formulation is stated. Necessary conditions for optimal paths are provided for cases accounting for constrained release of the passenger, termination conditions for the task, as well as retrieval and constrained retrieval of the passenger. A problem involving two marsupial agents collecting information about a stationary object while avoiding detection is then formulated. Necessary conditions for optimal paths are provided and rectilinear motion is demonstrated to be optimal for both agents.PhDAerospace EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/111439/1/jfargeas_1.pd

Agents mobiles coopérants pour les environnements dynamiques

A partir de l'étude de la mobilité dans les paradigmes de programmation pour les systèmes distribués et des différents architectures réseaux, et principalement celles sans-fils, nous avons pu identifier le problème de la gestion des unités mobiles (PDA, smartphone, ...) lorsque l'on souhaite les intégrer dans Internet. Leurs déplacements introduisent un fort dynamisme matériel qui ne permet plus d'utiliser les techniques classiques d'un internet et d'obtenir un système gérant globalement la localisation de toutes les unités. Cette absence de gestion globale remet en cause les méthodes classiques de conception fondées sur un système offrant une représentation stable de l'environnements. Dans ce contexte, nous avons étudié la conception basée sur les agents mobiles, programmes se déplaçant de site en site de manière autonome, afin de démontrer leur utilité dans des environnements dynamiques à l'échelle d'Internet, et ce, en l'absence d'un système capable de gérer la localisation globale. ABSTRACT : From the study of programming paradigms used in distributed systems and recent network architectures, especially wireless ones, we distinguish the problem of mobile unit management (PDA, smartphone, ...) when they are involved in the Internet. Their mobility introduces a high physical dynamism which leads to reconsider design patterns used in an intranet. Such systems do not allow to provide a global view of the distribution. This absence of global view implies to revisit classical design approaches based upon a system supplying a stable context representation. Therefore, we have studied a design approach based upon mobile agents, namely programs moving from site to site in an autonomous way. We demonstrate their usefulness in such dynamic environments at large scale in the Internet, in which there exits non global location service

Mobile agents for testing web services in next generation networks

Web services are emerging as the standard paradigm for program-to-program interactions on Internet. They are gaining more and more momentum and are expected to play a key role in Next Generation Networks. For these reasons, their management is becoming critical. Fault management is one of the most challenging areas of network and service management. It includes fault detection, isolation and repair. This paper proposes a Web service-based architecture for detecting faults in Web services. The architecture is rooted in passive testing. Passive testing consists of observing and analyzing messages the component under test exchanges with its environment. The passive testers of our architecture are designed as Web services. The components of the architecture are presented and the potential interfacing technologies are evaluated. This evaluation has led us to the selection of mobile agents