Computer simulation is the most common approach to studying wireless ad-hoc routing algorithms. The results, however, are only as good as the models the simulation uses. One should not underestimate the importance of ...
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ISBN:
(纸本)0769521118
Computer simulation is the most common approach to studying wireless ad-hoc routing algorithms. The results, however, are only as good as the models the simulation uses. One should not underestimate the importance of validation, as inaccurate models can lead to wrong conclusions. In this paper we use direct-execution simulation to validate radio models used by ad-hoc routing protocols, against real-world experiments. This paper documents a common testbed that supports direct execution of a set of ad-hoc routing protocol implementations in a wireless network simulator The testbed reads traces generated from real experiments, and uses them to drive direct-execution implementations of the routing protocols. Doing so we reproduce the same network conditions as in real experiments. By comparing routing behavior measured in real experiments with behavior computed by the simulation, we are able to validate the models of radio behavior upon which protocol behavior depends. We conclude that it is possible to have fairly accurate results using a simple radio model, but the routing behavior is quite sensitive to one of this model's parameters. The implication is that one should i) use a more complex radio model that explicitly models point-to-point path loss, or ii) use measurements from an environment typical of the one of interest, or iii) study behavior over a range of environments to identify sensitivities.
The paper presents a new architecture for systems based on run-time reconfigured shared memory processor clusters meant for implementation using network on chip technology. Clusters constitute local data exchange sub-...
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ISBN:
(纸本)0769522106
The paper presents a new architecture for systems based on run-time reconfigured shared memory processor clusters meant for implementation using network on chip technology. Clusters constitute local data exchange sub-networks, which dynamically connect processors with shared memory modules. The sub-networks enable exposure of data from one processor's data cache for reading by other processors to their data caches. This inter-processor data exchange paradigm, called "communication on the fly", enables direct communication between processor data caches. Dual-ported data caches are assumed to enable parallel reading and writing data between the caches and memory modules. In the proposed architecture, programs are executed according to a cache-controlled macro data flow execution model. Computational tasks are so defined, as to eliminate re-loading of data caches during task execution. A special program macro-data flow graph representation enables modeling of program behaviour for different architectural and program structure assumptions. simulation results of symbolic execution of program graphs of matrix multiplication are presented in the paper. They show suitability of the proposed architecture for very fine grain parallel computations.
Large complex system simulation in various fields of science and engineering requires tremendous computational resources;however sequential execution algorithms badly limited its performance. So recently there has bee...
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ISBN:
(纸本)3540240764
Large complex system simulation in various fields of science and engineering requires tremendous computational resources;however sequential execution algorithms badly limited its performance. So recently there has been a great deal of interest in parallel and distributedsimulation, which runs on multiple processors to accelerate simulation. This paper begins with introduction of synchronization mechanisms. The emphasis of this paper is to provide and describe the implementation of the flexible cycle algorithm. This improved algorithm solves some fatal problems of conservative or optimistic algorithms, resulting in the best of both methods. Finally we also analyze how to compute the performance parameter M of this algorithm in detail.
The paper deals with simulation and analysis tools of control system with distributed inputs and outputs based on TCP/IP and UDP/IP protocols. These protocols are not strictly prepared for industrial control applicati...
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The proceedings contain 190 papers. The special focus in this conference is on Grid Application, Peer to Peer Computing and Grid Architectures. The topics include: A computer systems approach to grid research;problems...
ISBN:
(纸本)3540219889
The proceedings contain 190 papers. The special focus in this conference is on Grid Application, Peer to Peer Computing and Grid Architectures. The topics include: A computer systems approach to grid research;problems of and mechanisms for instantiating virtual organizations;making grid computing real for high performance and enterprise computing;scientific issues, methodology, and practice in china;enabling scientific study of dynamic grid behavior;on-demand business collaboration enablement with services computing;a research on the framework of grid manufacturing;implementation of grid-enabled medical simulation applications using workflow techniques;a new overlay network based on can and chord;a distributed media service system based on Globus data-management technologies;a web-GIS based urgent medical rescue CSCW system for SARS disease prevention;a model for adapting service-oriented grid applications;conceptual framework for recommendation system based on distributed user ratings;the design and implementation of the gridlab information service;a new navigation method for web users;application availability measurement in computational grid;research and application of distributed fusion system based on grid computing;an efficient and self-configurable publish-subscribe system;the implementation of the genetic optimized algorithm of air craft geometry designing based on grid computing;the design of adaptive platform for visual-intensive applications over the grid;some grid automata for grid computing;the granularity analysis of MPI parallel programs;integration of the distributedsimulation into the OGSA model and an extendable grid simulation environment based on gridsim.
The proceedings contain 26 papers. The special focus in this conference is on Membrane Computing. The topics include: Proton pumping P systems;a binary data structure for membrane processors;parsing with active P auto...
ISBN:
(纸本)354020895X
The proceedings contain 26 papers. The special focus in this conference is on Membrane Computing. The topics include: Proton pumping P systems;a binary data structure for membrane processors;parsing with active P automata;universality of minimal symport/antiport;collapsing hierarchies of parallel rewriting P systems without target conflicts;evolution and observation;tiling rectangular pictures with P systems;simulating boolean circuits with P systems;P systems running on a cluster of computers;implementing in prolog an effective cellular solution to the knapsack problem;a petri net view;P systems generating hexagonal picture languages;a membrane system for the leukocyte selective recruitment;P systems with cutting/recombination rules assigned to membranes;the number of membranes matters;an agent-based behavioural model of monomorium pharaonis colonies;can hyperbolic geometry be of help for P systems;a linear-time solution to the knapsack problem using P systems with active membranes;a reconfigurable hardware membrane system;P systems and petri nets;simulation of mobile ambients by P systems;computing partial recursive functions by transition P systems;P systems with external input and learning strategies;a distributedsimulation of transition P systems and about splicing P systems with immediate communication and non-extended splicing P systems.
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