Search results for " computing"
showing 10 items of 2075 documents
Multipath extensions to the DYMO routing protocol
2007
Multipath routing is a technique that can improve performance, specially in mobile ad hoc networks. Due to traffic dispersion it can perform load balancing; minimize the energy consumed by nodes or prevent traffic analysis. In this work we focus on enhancing the DYMO protocol to support multipath routing. We study the impact of traffic dispersion on both UDP and TCP traffic when varying a set of parameters.
Simulation-based Evaluation of DMAMAC - A Dual-Mode Adaptive MAC Protocol for Process Control
2015
Control systems automation is widely used in many industrial domains and have strong requirements on delay, throughput, robustness, and reliability. In the domain of networked control systems, the medium of communication is increasingly involving wireless communication along-side conventional wired communication. Issues ranging from energy efficiency and reliability to low-bandwidth have to be addressed to enable the transition to increased use of wireless communication. In earlier work, we have proposed the Dual-Mode Adaptive MAC (DMAMAC) protocol relying on a combination of Time Division Multiple Access (TDMA) and Carrier Sense Multiple Access (CSMA). The DMAMAC protocol is able to dynami…
Resource Self-management under an SLA within a Cloud Networking Environment
2015
International audience; Today, cloud networking is one of the recent research areas in the cloud computing research communities. The main drawback of cloud networking consists in the lack of Quality of Service (QoS) guarantee and management in conformance with a corresponding Service Level Agreement (SLA). In this paper, we propose a framework for self-establishing an end-to-end SLA between a Cloud Service User (CSU) and several Cloud Service Providers (CSPs) in a cloud networking environment (inter-cloud Broker and Federation architecture). Then, we propose the self-management of cloud resources under the established SLA using specific autonomic cloud managers. We simulate our proposed fra…
PTNet: An efficient and green data center network
2017
International audience; In recent years, data centers have witnessed an exponential growth for hosting hundreds of thousands of servers as well as to accommodating a very large demand for resources. To fulfill the required level of demand, some approaches tackled network aspects so to host a huge number of servers while others focused on delivering rapid services to the clients by minimizing the path length between any two servers. In general, network devices are often designed to achieve 1:1 oversubscription. Alternatively, in a realistic data center environment, the average utilization of a network could vary between 5% and 25%, and thus the energy consumed by idle devices is wasted. This…
New Optimization and Security Approaches to Enhance the Smart Grid Performance and Reliability
2016
International audience; Nowadays, the Smart Grid (SG) is becoming smarter thanks to the integration of different information and communication technologies to enhance the reliability and efficiency of the power grid. However, several issues should be met to ensure high SG performance. Among these issues, we cite the problem of electric vehicles (EVs) integration into the SG to avoid electricity intermittence due to the important load that EVs can create. Another issue is the SG communication network security that can be attempted by malicious intruders in order to create damages and make the power grid instable. In this context, we propose at a first level a Bayesian game-theory model that …
Comparative Study of the Mobile Learning Architectures
2016
International audience; With the emergence of mobile devices (Smart Phone, PDA, UMPC, game consoles, etc.), learning is changing from electronic learning (e-Learning) to mobile learning (m-learning). In fact, due to the mobility feature, it seems that the m-learning have to be adapted with the change within the context. Several researches addressed this issue and implemented a mobile learning environment to prove its usefulness and feasibility in various domains. In this article, we conduct a comparative study between a list of mobile learning architectures and methods that are presented in the literature. The performance of these architectures is evaluated based on several criteria, such a…
Extending CSG with projections: Towards formally certified geometric modeling
2015
We extend traditional Constructive Solid Geometry (CSG) trees to support the projection operator. Existing algorithms in the literature prove various topological properties of CSG sets. Our extension readily allows these algorithms to work on a greater variety of sets, in particular parametric sets, which are extensively used in CAD/CAM systems. Constructive Solid Geometry allows for algebraic representation which makes it easy for certification tools to apply. A geometric primitive may be defined in terms of a characteristic function, which can be seen as the zero-set of a corresponding system along with inequality constraints. To handle projections, we exploit the Disjunctive Normal Form,…
Une approche Web sémantique et combinatoire pour un système de recommandation sensible au contexte appliqué à l'apprentissage mobile
2014
National audience; Au vu de l'émergence rapide des nouvelles technologies mobiles et la croissance des offres et besoins d'une société en mouvement en formation, les travaux se multiplient pour identifier de nouvelles plateformes d'apprentissage pertinentes afin d'améliorer et faciliter le processus d'apprentissage à distance. La prochaine étape de l'apprentissage à distance est naturellement le port de l'e-learning (apprentissage électronique) vers les nouveaux systèmes mobiles. On parle alors de m-learning (apprentissage mobile). La recherche d'informations dans le domaine du m-learning peut être définie comme une activité dont la fi-nalité est de localiser et de délivrer des contenus d'a…
Ontology and protocol secure for SCADA: Int. J. of Metadata, Semantics and Ontologies, 2014 Vol.9, No.2, pp.114 - 127
2014
International audience; In this work, we present a semantic cyber security system and we study its semantic intelligent systems vulnerabilities, focusing on the semantic attacks. For resolving semantic problems we propose a security global solution for the new generation of SCADA systems. The proposed solution aims at protecting critical semantic SCADA processes from the effects of major failures and semantic vulnerabilities in the modern IT-SCADA network. We used a security block in the global network access point, security protocols deployed in different network (OSI) levels and security ontologies deployed in security devices. We used our mixed coordinates (ECC) cryptography solution, th…
NoC based virtualized FPGA as cloud Services
2016
International audience; Web-based applications are increasingly demanding many computationally intensive services. On the other hand, FPGA-based hardware accelerators(HwAcc) provide good performance in accelerating computationally intensive applications. In addition, some FPGAs support a dynamic partial reconfig-uration (DPR) techniques to virtualize and share the FPGA underlying hardware resources in time multiplexing during run-time to save resource and power consumption. Integrating FPGA in a cloud environment is an indispensable way to improve efficiency and provide acceleration services to demanding users. More importantly, in recent years it was proved that FPGA resources deployed in …