The objective of this paper is to present a feasible and efficient methodology that improves client mobility management under ubiquitous information service network. We base our system on the Open Integrated Service N...
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ISBN:
(纸本)0818682272
The objective of this paper is to present a feasible and efficient methodology that improves client mobility management under ubiquitous information service network. We base our system on the Open Integrated Service Network Architecture and propose a hybrid infrastructure with facilities of both a centralized Network Management Center (NMC) and a distributed Home Base Node (HEN). We also have criteria for choosing a HEN with minimum cost by computing the expected registration cost and location tracking cost according to users characteristics and called frequencies. Running a simulation, results show that our methodology is able to save up to 40% of the cost comparing to that of IS-41 when the value of Call-Mobility Ratio (CMR) is in the range of (1, 100), which means either clients are called with high frequencies or are moving with low mobilities. As the value of CMR goes down to the range of (0.01, 1), which means either clients are called with low-frequencies or are moving with high mobilities we may save up to 50% cost.
Edge detection and shape detection in digital images are very computationally intensive problems. parallel algorithms can potentially provide significant speedups while preserving the quality of the result obtained. H...
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Edge detection and shape detection in digital images are very computationally intensive problems. parallel algorithms can potentially provide significant speedups while preserving the quality of the result obtained. Hough and Radon Transforms are projection-based transforms which are commonly used for edge detection and shape detection respectively. We propose in this paper various new parallel algorithms which exploit both task and data parallelism available in Hough and Radon transforms algorithms. A memory scalable aggressive task parallel algorithm is shown to be the most optimal algorithm in terms of memory scalability and performance on an IBM SP2.
The proceedings contain 18 papers. The special focus in this conference is on Modeling Techniques and Tools for Computer Performance Evaluation. The topics include: A performability modeling environment tool;dependabi...
ISBN:
(纸本)9783540631019
The proceedings contain 18 papers. The special focus in this conference is on Modeling Techniques and Tools for Computer Performance Evaluation. The topics include: A performability modeling environment tool;dependability evaluation and the optimization of performability;design and implementation of a network computing platform using JAVA;storage alternatives for large structured state spaces;an efficient disk-based tool for solving very large markov models;efficient transient overload tests for real-time systems;towards an analytical tool for performance modeling of ATM networks by decomposition;an embedded network simulator to support network protocols’ development;synchronized two-way voice simulation for internet phone performance analysis and evaluation;processes as language-oriented building blocks of stochastic petri nets;measurement tools and modeling techniques for evaluating WEB server performance;workload characterization of input/output intensive parallel applications;interval based workload characterization for distributed systems;bounding the loss rates in a multistage ATM switch;simple bounds for queues fed by markovian sources and on queue length moments in fork and join queuing networks with general service times.
In this paper, we present an extension to Kerry Raymond's tree based distributed mutual exclusion algorithm to make it fault tolerant. The algorithm uses a spanning tree of a computer network. With N nodes in the ...
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In this paper, we present an extension to Kerry Raymond's tree based distributed mutual exclusion algorithm to make it fault tolerant. The algorithm uses a spanning tree of a computer network. With N nodes in the network the number of messages exchanged per critical section entry is typically O(log N). The novelty of the algorithm lies in each node holding information only about its immediate neighbors in the spanning tree. We basically present a protocol to make the algorithm tolerant to single node/link failure and associated network partition. This protocol assumes that the graph of the underlying network is biconnected. Basically we attempt reconfiguration of the tree after isolating the failed components. With this enhancement a significant number of cases in which the algorithm would have halted due to lack of communication paths, can be effectively handled by utilizing alternative communication paths now available, thus continuing to provide the mutual exclusion service.
distributed Shared Memory (DSM) offers programmers a shared memory abstraction on top of an underlying network of distributed memory machines. advances in network technology and price/performance of workstations sugge...
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distributed Shared Memory (DSM) offers programmers a shared memory abstraction on top of an underlying network of distributed memory machines. advances in network technology and price/performance of workstations suggest that DSM will be the dominant paradigm for future high-performance computing. However, as long running DSM applications scale to hundreds or even thousands of machines, the probability of a node or network link failing increases. Fault tolerance is typically achieved via "checkpointing" techniques that allow applications to "roll back" to a recent checkpoint rather than restarting. High-performance DSM systems using relaxed memory consistency are significantly more difficult to checkpoint than uniprocessor or message passing architectures. This paper describes previous approaches to checkpointing message passing parallel programs along with extensions to DSM systems.
This paper addresses the following scheduling problem: given a precedence graph with communication costs and a machine architecture with different types of processors, construct a schedule that runs on the given archi...
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This paper addresses the following scheduling problem: given a precedence graph with communication costs and a machine architecture with different types of processors, construct a schedule that runs on the given architecture at the minimum possible execution time. The main contributions are: Firstly, we present a static scheduling algorithm that keeps processors idle for future important tasks and fills idle time slots incurred due to interprocessor communication. Secondly, to evaluate the effectiveness of the algorithm, we develop a lower bound on the length of a optimal schedule as a yardstick. Experiments show that this new approach produces better schedules and takes much less compile time.
We examine the use of a shared memory programming model to address the problem of portability between distributed memory and shared memory architectures. We conduct this evaluation by extending an existing programming...
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We examine the use of a shared memory programming model to address the problem of portability between distributed memory and shared memory architectures. We conduct this evaluation by extending an existing programming model, the parallel C Preprocessor, with a type qualifier interpretation of the data sharing keywords borrowed from the Split-C and AC compilers. We evaluate the performance of the resulting programming model on a wide range of shared memory and distributed memory computing platforms using several numerical algorithms as benchmarks. We find the type-qualifier-based programming model capable of efficient execution on distributed memory and shared memory architectures.
Bridging models, such as the BSP (bulk synchronous parallel) model, tend to abstract the characteristics of interconnection networks using a small set of parameters, by dividing the computation into supersteps and org...
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Bridging models, such as the BSP (bulk synchronous parallel) model, tend to abstract the characteristics of interconnection networks using a small set of parameters, by dividing the computation into supersteps and organizing the communication into global patterns called h-relations. In this paper, we evaluate (through experimental results conducted on a wormhole-routed 2D torus and a quaternary fat-tree with 256 processing nodes) the execution time of three families of h-relations with variable degree of imbalance. We also prove a strong result that links the communication performance of the fat-tree with the BSP abstraction of the interconnection network. Given a generic h-relation, we can provide a value of g (the gap) that, in the worst case, slightly overestimates the completion time and is very close to optimality.
Techniques of customizing and extending operating systems (OSs) have a growing impact on system architectures in the field of distributedcomputing and parallel programming. Even if traditional methods of adaption hav...
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Techniques of customizing and extending operating systems (OSs) have a growing impact on system architectures in the field of distributedcomputing and parallel programming. Even if traditional methods of adaption have been limited to the user-level, modern OSs cannot do without kernel support. Hence concepts and structures of microkernel architectures must be redefined to meet the requirements of today's and future applications. We propose a new customizable low-level OS architecture-the Dycos kernel. We discuss customization demands on microkernels and describe the basic kernel concept. Dycos is an object-based approach providing a toolbox of operations to build user-definable compositions of kernel structures. The Dycos approach has been evaluated on a Solaris 2.5.1 platform.
LOGFLOW is a distributed Prolog implementation running on transputer networks, developed at KFKI-MSZKI. To improve capabilities and the power of LOGFLOW, the system is ported onto workstation-clusters under the name W...
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LOGFLOW is a distributed Prolog implementation running on transputer networks, developed at KFKI-MSZKI. To improve capabilities and the power of LOGFLOW, the system is ported onto workstation-clusters under the name WS-LOGFLOW. The new platform requires modification in the architecture of the system, in token transportation and in the work-distribution. This paper presents the modified architecture of WS-LOGFLOW, the new token distribution scheme and some details of the portation: processes, intra-node shared-memory communication, inter-node PVM-based message-passing communication.
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