Programmation par objets et parallélisme de données dans Paladin

Nous proposons d'exprimer la parallélisation par distribution des données et le modèle d'exécution SPMD à l'aide des mécanismes de la programmation par objets. Nous montrons qu'il est possible, en utilisant un langage à objets séquentiel, de développer des composants logiciels réutilisables décrivant à la fois la distribution des données et des algorithmes manipulant ces données de manière efficace. Pour illustrer notre propos, nous décrivons la bibliothèque \Paladinpunct, conçue selon cette approche et dédiée au calcul d'algèbre linéaire sur machine parallèle

Combinatorial Optimization Algorithms for Radio Network Planning

An extended version of this paper was published in the Journal of Theoretical Computer Science (TCS), Special Issue on Combinatorics and Computer Science, 265(1):235-245, 2001. See http://hal.archives-ouvertes.fr/hal-00346034/fr/International audienc

Content-based communication in disconnected mobile ad hoc networks

In content-based communication, information flows to-wards interested hosts rather than towards specifically set destinations. This new style of communication perfectly fits the needs of applications dedicated to information shar-ing, news distribution, service advertisement and discovery, etc. In this paper we address the problem of supporting content-based communication in partially or intermittently connected mobile ad hoc networks (MANETs). The protocol we designed leverages on the concepts of opportunistic net-working and delay-tolerant networking in order to account for the absence of end-to-end connectivity in disconnected MANETs. The paper provides an overview of the protocol, as well as simulation results that show how this protocol can perform in realistic conditions. 1

Combinatorial Optimization Algorithms for Radio Network Planning

Special Issue on Combinatorics and Computer ScienceInternational audienceThis paper uses a realistic problem taken from the telecommunication world as the basis for comparing different combinatorial optimization algorithms. The problem recalls the minimum hitting set problem, and is solved with greedy-like, Darwinism and genetic algorithms. These three paradigms are described and analyzed with emphasis on the Darwinism approach, which is based on the computation of epsilon-nets

Embedding Data Parallelism in Sequential Object Oriented Languages

International audience[Excerpt from the introduction] The spreading of Distributed Memory Parallel Computers (DMPCs) is hampered by the fact that writing or porting application programs to such architectures is a difficult, time-consuming and error-prone task. Nowadays software environments for commercially available DMPCs mainly consist of libraries of routines to handle communications between processes. We believe that the reuse of carefully designed software components could help to manage the complexity of concurrent programming. Our approach aims at embedding the scalable data parallelism programming model in an OOL. This approach is orthogonal to those where objects can be made active and invocations of methods result in actual message passing communications (sometimes referred to as functional parallelism, because the definition of processes is determined by the decomposition into sub-tasks). We believe that functional parallelism does not allow an easy and efficient mapping of large scale computing algorithms onto the very high number of processors that are made available in a DMPC. [...

POM: a Virtual Parallel Machine Featuring Observation Mechanisms

International audienceWe describe in this paper a Parallel Observable virtual Machine (POM), which provides a homogeneous interface upon the communication kernels of parallel architectures. POM was designed so as to be ported easily and eciently on numerous parallel platforms. It provides sophisticated features for observing distributed executions

Disruption-Tolerant Wireless Biomedical Monitoring for Marathon Runners: a Feasibility Study

International audienceOff-the-shelf wireless sensing devices open a wide range of perspectives for tetherless biomedical monitoring. Yet most applications considered to date imply either indoor realtime data streaming or ambulatory data recording. Disruption-tolerant networking is a means to cope with challenging situations where continuous end-to-end connectivity between communicating devices cannot be guaranteed. In this paper we investigate the possibility of using this approach to remotely monitor the cardiac activity of runners during a marathon race, using off-the shelf sensing devices and a limited number of base stations deployed along the marathon route. Preliminary experiments show that such a scenario is indeed viable, although special attention must be paid to balancing the requirements of ECG monitoring with the constraints of episodic, low-rate transmissions

Biomedical Monitoring of Non-Hospitalized Subjects using Disruption-Tolerant Wireless Sensors

International audienceThe proliferation of private, corporate and community Wi-Fi hotspots in city centers and residential areas opens up new opportunities for the collection of biomedical data produced by sensors carried by mobile non-hospitalized subjects. In this paper we investigate the possibility of using these many hotspots as gateways for biomedical data transmission. A disruption-tolerant application is presented, that can record biomedical data while the subject is not in the range of a Wi-Fi hotspot, and upload recorded data to a remote monitoring center whenever a hotspot is located nearby. Results of a field trial are presented, with a scenario involving a subject wearing an ECG-enabled sensor, walking in the streets of a residential area

Polymorphic Matrices in Paladin

International audienceScientific programmers are eager to take advantage of the computational power offered by Distributed Computing Systems (DCSs), but are generally reluctant to undertake the porting of their application programs onto such machines. The DCS commercially available today are indeed widely believed to be difficult to use, which should not be a surprise since they are traditionally programmed with software tools dating back to the days of punch cards and paper tape. We claim that provided modern object oriented technologies are used, these computers can be programmed easily and efficiently. In EPEE, our Eiffel Parallel Execution Environment, we propose to use a kind of parallelism known as data-parallelism, encapsulated within classes of the Eiffel sequential object-oriented language, using the SPMD (Single Program Multiple Data) programming model. We describe our method for designing with this environment Paladin, an object-oriented linear algebra library for DCSs. We show how dynamic binding and polymorphism can be used to solve the problems set by the dynamic aspects of the distribution of linear algebra objects such as matrices and vectors