Search results for "Distributed computing"
showing 10 items of 622 documents
HOW SMART DOES AN AGENT NEED TO BE?
2005
The classic distributed computation is done by atoms, molecules or spins in vast numbers, each equipped with nothing more than the knowledge of their immediate neighborhood and the rules of statistical mechanics. These agents, 1023 or more, are able to form liquids and solids from gases, realize extremely complex ordered states, such as liquid crystals, and even decode encrypted messages. We will describe a study done for a sensor-array "challenge problem" in which we have based our approach on old-fashioned simulated annealing to accomplish target acquisition and tracking under the rules of statistical mechanics. We believe the many additional constraints that occur in the real problem ca…
Code Interoperability and Standard Data Formats in Quantum Chemistry and Quantum Dynamics: The Q5/Q5cost Data Model
2014
Code interoperability and the search for domain-specific standard data formats represent critical issues in many areas of computational science. The advent of novel computing infrastructures such as computational grids and clouds make these issues even more urgent. The design and implementation of a common data format for quantum chemistry (QC) and quantum dynamics (QD) computer programs is discussed with reference to the research performed in the course of two Collaboration in Science and Technology Actions. The specific data models adopted, Q5Cost and D5Cost, are shown to work for a number of interoperating codes, regardless of the type and amount of information (small or large datasets) …
A grid ant colony algorithm for the orienteering problem
2005
In this paper we propose a distributed ant colony algorithm to solve large scale orienteering problem instances. Our approach is based on a multi-colony strategy where each colony works in an independent portion (cluster) in the original graph. This results in no need for communicating pheromones information among colonies and in increasing speedup. We have implemented our algorithm as a .NET Web services infrastructure following a grid computing philosophy and we provide some promising experimental results to show the feasibility and effectiveness of our approach
On the coupling between agent internal and agent/ environmental dynamics: Development of spatial representations in evolving autonomous robots
2008
In this article we describe how a population of evolving robots can autonomously develop forms of spatial representation which allow them to self-localize and to discriminate different locations of their environment by integrating sensory-motor information over time. The evolving robots also display a remarkable ability to generalize their skill in new environmental conditions that they have never experienced before. The analysis of the obtained results indicates that the evolved robots come up with simple and robust solutions that exploit quasi-periodic limit cycle dynamics emerging from the coupling between the robot/environmental dynamics and a robot's internal dynamics. More specifical…
Ontonuts: Reusable Semantic Components for Multi-agent Systems
2009
The volumes of data in information systems are growing drastically. The systems become increasingly complex in trying to handle heterogeneity of ubiquitous components, standards, data formats, etc. According to the vision of Autonomic Computing, the complexity can be handled by introducing self-manageable components able to "run themselves." Agent Technology fits this vision, whereas interoperability among autonomic components can be tackled by Semantic Technologies. The problem of efficient heterogeneous data sharing, exchange and reuse within such systems plays a key role. We present an approach of constructing semantic capabilities (self-descriptive functional components) for software ag…
Specification and Implementation of Multicast Congestion Control Stair Protocol: Use Case with Multimedia Ubiquitous Networks
2008
Ubiquitous and efficient multicast data delivery service is essential to the success of large-scale group communication applications. In this framework, congestion control through ubiquitous networks is a hot topic for multicast real time protocols. In this paper, authors present specification and implementation of simulate TCP's AIMD with rate-based (STAIR), a multicast congestion control mechanism. Authors have enhanced this approach because they have modeled it using Unified Modeling Language with real time extensions (UML-RT) as a formal specification tool. More to the point point, they introduce a multimedia ubiquitous network which they have used as a reference model to promote their …
Software Requirements for Ubiquitous Ad Hoc Mobile Networks: An Example of a Bluetooth Application
2009
In contrast with the simple and elegant concept of global computing, also called ubiquitous computing - where daily life objects get now computing capacity and interact among them to provide a wide range of services to users - a major difficulty is arising with the software engineering process to develop applications for these devices. This article discusses the additional parameters that should be taken into account when designing and developing software for ubiquitous devices in ad-hoc networks. In these networks the mobility of the devices could increase the complexity of the requirements to be considered. As a case study, we present a Bluetooth application that has been developed to ful…
Availability in BitTorrent Systems
2007
In this paper, we investigate the problem of highly available, massive-scale file distribution in the Internet. To this end, we conduct a large-scale measurement study of BitTorrent, a popular class of systems that use swarms of actively downloading peers to assist each other in file distribution. The first generation of BitTorrent systems used a central tracker to enable coordination among peers, resulting in low availability due to the tracker's single point of failure. Our study analyzes the prevalence and impact of two recent trends to improve BitTorrent availability: (i) use of multiple trackers, and (ii) use of Distributed Hash Tables (DHTs), both of which also help to balance load be…
Tracking control of network distributed systems in presence of variable time delay and loss of information
2006
This paper deals with the control of network distributed systems which has been at the centre of interest in a wide area of research in the last few year. The control of such systems is very difficult because the communication networks inevitably introduce variable time delays and possible lost of samples. In particular, it is proposed an extension of the approach, derived in the contest of the optimal stochastic regulator problem [1], [2], to the remote tracking problem considering a distributed control system in which the signals from the transducers to the controller and from the controller to the actuator are transmitted through a communication network with variable delays and possible …
Skeletons for parallel image processing: an overview of the SKiPPER project
2002
International audience; This paper is a general overview of the SKIPPER project, run at Blaise Pascal University between 1996 and 2002. The main goal of the SKIPPER project was to demonstrate the appli- cability of skeleton-based parallel programming techniques to the fast prototyping of reactive vision applications. This project has produced several versions of a full-fledged integrated pa- rallel programming environment (PPE). These PPEs have been used to implement realistic vi- sion applications, such as road following or vehicle tracking for assisted driving, on embedded parallel platforms embarked on semi-autonomous vehicles. All versions of SKIPPER share a common front-end and reperto…