Search results for "Tribute"
showing 10 items of 1455 documents
On the Characterization of Distributed Virtual Environment Systems
2003
Distributed Virtual Environment systems have experienced a spectacular growth last years. One of the key issues in the design of scalable and cost-effective DVE systems is the partitioning problem. This problem consists of efficiently assigning clients (3-D avatars) to the servers in the system, and some techniques have been already proposed for solving it.
Cooperative Medium Access Control in Wireless Networks: The Two-Hop Case
2009
Cooperative communication has been recently proposed as a powerful means to improve network performance in wireless networks. However, most existing work focuses solely on one-hop source-destination cooperation. In this paper, we propose a novel cooperative MAC mechanism that is specially designed for two-hop cooperation communications where the source node and the destination node cannot hear each other directly. In this case, cooperative communication is operated in a two-hop manner and transmit-diversity is achieved by the reception of the same data packet forwarded through multiple relays towards a single destination. The proposed scheme employs an efficient relay selection algorithm to…
An optimal energy efficient cooperative retransmission MAC scheme in wireless networks
2011
While the benefits of cooperative diversity have been well studied in the literature, cooperative MAC protocol design has also attracted much attention recently. In the single-relay Cooperative Automatic Repeat reQuest (C-ARQ) protocol, the best relay node is selected in a distributed manner by relays using different backoff time before packet retransmission. However, this relay selection scheme does not work efficiently in a dense network scenario, due to possible high collision probability among different contending relays. In this paper, we propose an optimized relay selection scheme to maximize system energy efficiency by reducing collision probability. The energy efficiency performance…
Improving big-data automotive applications performance through adaptive resource allocation
2019
In automotive applications, connected vehicles (CVs) can collect various information (external temperature, speed, location, etc.) and send them to a central infrastructure for exploitation in a wide range of applications: Eco-Driving, fleet management, environmental monitoring, etc. Such applications are known to generate a massive volume of data that is processed in real or near real time (i.e., data streams) depending on the target application requirements. To handle this data volume, big data architectures, based on stream computing paradigm, are usually adopted. Within this paradigm, data are continuously processed by a set of operators (elementary operations) instances. Further, a str…
Two memorial congresses in tribute of Omar Prakash, MD, PhD
1994
Both memorial congresses presented the large field of computing and technology in anaesthesia and intensive care. Many of the contributors were personal friends of Omar and the spirit of Dr. Omar Prakash was present during these congresses. Quite certainly, he would have enjoyed both of the two occasions. They proved that the idea Dr. Omar Prakash first sparked in early eighties, of international meetings for scientists to come to meet friends and interchange ideas, is going strong. In fact, people spontaneously reached agreement that this tradition of Memorial congresses should be continued in the future. Whenever such a congress is to be arranged, you will see it being announced in this v…
Trust-based framework for security enhancement of P2PSIP communication systems
2009
Today, Peer-to-Peer SIP based communication systems have attracted much attention from both academia and industry. The decentralized nature of P2P might provide the distributed peer-to-peer communication system without help of the traditional SIP server. However, it comes to the cost of reduced trustworthiness and may cause security problems, e.g. privacy leaks, unpredictable availability, etc. In this paper, we investigate on P2PSIP security issues and propose a subjective based trust model that offers trust services during P2PSIP session establishment. The main issues considered in this model include opinion calculation, opinion maintenance, data confidentiality and integrity, message rou…
Grid production with the ATLAS Event Service
2018
ATLAS has developed and previously presented a new computing architecture, the Event Service, that allows real time delivery of fine grained workloads which process dispatched events (or event ranges) and immediately streams outputs. The principal aim was to profit from opportunistic resources such as commercial cloud, supercomputing, and volunteer computing, and otherwise unused cycles on clusters and grids. During the development and deployment phase, its utility also on the grid and conventional clusters for the exploitation of otherwise unused cycles became apparent. Here we describe our experience commissioning the Event Service on the grid in the ATLAS production system. We study the …
Proactive Future Internet: Smart Semantic Middleware for Overlay Architecture
2009
Some initiatives towards Future Internet, e.g., GENI, DARPA's Active Networks, argue the need for programmability of the network components. Some other initiatives extend this with argumentation for declarative networking, where the behavior of a network component is specified using some high-level declarative language, with a software-based engine implementing the behavior based on that specification. Our Proactive Future Internet (PROFI) vision follows these initiatives targeting also the following two problems: interoperability of the network elements programmed by different organizations, and the need for flexible cooperation among network elements, including coordination, conflict reso…
A Multi-Relay Cooperative Automatic Repeat Request Protocol in Wireless Networks
2010
This paper proposes a Multi-relay Cooperative Automatic Repeat ReQuest protocol (MC-ARQ) for IEEE 802.11 based wireless networks. The proposed distributed relay selection scheme not only selects the best relays but also solves the collision problem among multiple contending relays, by sorting the relays in the network according to their instantaneous channel quality with the destination node. No prior information or explicit signaling among relay nodes is required. Both analytical and simulation results show that significant benefits can be achieved with the MC-ARQ protocol, compared with both the recently proposed PRCSMA scheme and the original non-cooperative DCF scheme.
A comparison study of evolutive algorithms for solving the partitioning problem in distributed virtual environment systems
2004
Fast Internet connections and the widespread use of high performance graphic cards are making Distributed Virtual Environment (DVE) systems very common nowadays. However, there are several key issues in these systems that should still be improved in order to design a scalable and cost-effective system. One of these key issues is the partitioning problem. This problem consists of efficiently assigning clients (3D avatars) to the servers in the system. In this paper, we present a comparison study of different modern heuristics for solving the partitioning problem in DVE systems, as an alternative to the ad hoc heuristic proposed in the literature. Performance evaluation results show that some…