Search results for "Distributed computing"
showing 10 items of 622 documents
Integration Issues of Distributed Generators Considering Faults in Electrical Distribution Networks
2014
In the recent years there is a great interest in integration of distributed generation (DG) units at distribution level; this integration leads to planning as well as operational challenges. Some possibilities to handle grid planning issues are addressed in this paper. Effects on grid protection, fault current level, and voltage profile are investigated and described for different types of DG units; the classification of DG units is based on their terminal characteristics in terms of real and reactive power delivering capability. Different scenarios for mis-coordination problems caused by DG interconnection are discussed. The effect of the DG on the voltage profile of a distribution network…
Cost-Effective Congestion Management for Interconnection Networks Using Distributed Deterministic Routing
2010
The Interconnection networks are essential elements in current computing systems. For this reason, achieving the best network performance, even in congestion situations, has been a primary goal in recent years. In that sense, there exist several techniques focused on eliminating the main negative effect of congestion: the Head of Line (HOL) blocking. One of the most successful HOL blocking elimination techniques is RECN, which can be applied in source routing networks. FBICM follows the same approach as RECN, but it has been developed for distributed deterministic routing networks. Although FBICM effectively eliminates HOL blocking, it requires too much resources to be implemented. In this …
VEF Traces: A Framework for Modelling MPI Traffic in Interconnection Network Simulators
2015
Simulation is often used to evaluate the behaviour and measure the performance of computing systems. Specifically, in high-performance interconnection networks, the simulation has been extensively considered to verify the behaviour of the network itself and to evaluate its performance. In this context, network simulation must be fed with network traffic, also referred to as network workload, whose nature has been traditionally synthetic. These workloads can be used for the purpose of driving studies on network performance, but often such workloads are not accurate enough if a realistic evaluation is pursued. For this reason, other non-synthetic workloads have gained popularity over last dec…
Efficient Switches with QoS Support for Clusters
2007
Current interconnect standards providing hardware support for quality of service (QoS) consider up to 16 virtual channels (VCs) for this purpose. However, most implementations do not offer so many VCs because they increase the complexity of the switch and the scheduling delays. We have shown that this number of VCs can be significantly reduced, because it is enough to use two VCs for QoS purposes at each switch port. In this paper, we cover the weaknesses of that proposal and, not only we reduce VCs, but we also improve performance due to the flexibility assigning buffer memory.
On the development of a communication-aware task mapping technique
2004
Clusters have become a very cost-effective platform for high-performance computing. In these systems, although currently existing networks actually provide enough bandwidth for the existing applications and workstations, the trend is towards the interconnection network becoming the system bottleneck. Therefore, in the future, scheduling strategies will have to take into account the communication requirements of the applications and the communication bandwidth that the network can offer. One of the key issues in these strategies is the task mapping technique used when the network becomes the system bottleneck.In this paper, we propose a communication-aware mapping technique that tries to mat…
Formal verification of a Cooperative Automatic Repeat reQuest MAC protocol
2012
Author's version of an article published in the journal: Computer Standards & Interfaces. Also available from the publisher at: http://dx.doi.org/10.1016/j.csi.2011.12.001 Cooperative communications, in which a relay node helps the source node to deliver its packets to the destination node, are able to obtain significant benefits in terms of transmission reliability, coverage extension and energy efficiency. A Cooperative Automatic Repeat reQuest (C-ARQ) MAC protocol has been recently proposed to exploit cooperative diversity at the MAC layer. in this paper, we validate the integrity and the validity of the C-ARQ protocol using formal methods. The protocol logic is modeled in SDL and implem…
Distributed estimation and control of water distribution networks by logical consensus
2014
In this study we present a methodology for backflow detec- tion through the interpretation of results from a network of Automatic Meter Reading. The approach is based on the so– called logical consensus theory and consists of a distributed failure detection and system reconfiguration. The effective- ness of the proposed method is showed through simulation within a prototypical water distribution network.
A Design Theory for Secure Information Systems Design Methods
2006
Many alternative methods for designing secure information systems (SIS) have been proposed to ensure system security. However, within all the literature on SIS methods, there exists little theoretically grounded work that addresses the fundamental requirements and goals of SIS design. This paper first uses design theory to develop a SIS design theory framework that defines six requirements for SIS design methods, and second, shows how known SIS design methods fail to satisfy these requirements. Third, the paper describes a SIS design method that does address these requirements and reports two empirical studies that demonstrate the validity of the proposed framework. peerReviewed
P2PRealm - Peer-to-Peer Network Simulator
2006
Peer-to-peer realm (P2PRealm) is an efficient peer-to-peer network simulator for studying algorithms based on neural networks. In contrast to many simulators, which emphasize on detailed network simulation, the speed of simulation in P2PRealm is essential, because neural networks require a time consuming training phase. Efficiency has been obtained by optimizing training loops inside the simulator, using Java native interface (JNI) as well as distributing the simulator to hundreds of workstations using the P2PDisCo platform. In this paper we describe the architecture of P2PRealm and its input/output interfaces. Also, we present the mechanisms used for internally optimizing the implementatio…
A New Environment for Distributed Multiple Vehicles Dynamics Control and Simulation
2007
Although there are many simulation softwares, the 3D multi-vehicle field needs further study. This paper describes a lightweight, full portable software environment for development, simulation and control of vehicles. This environment simulates ground wheeled vehicles and their environment. Multi vehicle study can be done adding the vehicle mathematical model and the 3D graphical model. The scenario is displayed as a 3D virtual reality environment in which all the objects are rendered using a combination of 3D primitive and/or pre-built 3D objects loaded from file. Since the software is made up of a set of multi-treading object-oriented Java classes, there are many advantages as portability…