Volunteer computing is an innovative approach to high performance computingthat relies on volunteers who donate their personal computers' unused resources to a computationally intensive research project. Prominen...
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ISBN:
(纸本)9780889866386
Volunteer computing is an innovative approach to high performance computingthat relies on volunteers who donate their personal computers' unused resources to a computationally intensive research project. Prominent volunteer computing projects include SETI@home, Folding@Home, and the Great Internet Mersenne Prime Search (GIMPS). Many volunteer computing projects are built upon a volunteer computing framework that abstracts functionality that is common to all volunteer computing projects, such as network communications, database access, and project management. these volunteer computing frameworks tend to be complex, limiting, and difficult to use. We have designed and implemented a new volunteer computing framework called the Simple Light-weight Infrastructure for Network computing (SLINC) that addresses the disadvantages we identified with existing frameworks. SLINC is a flexible and extensible volunteer computing framework that will enable researchers to more easily build volunteer computing projects.
this paper research on how to select a subtree with exactly k leaves and a diameter of at most 1, which minimizes the distance from the farthest vertex to the subtree. We call such a subtree (k, l)-center of a tree ne...
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ISBN:
(纸本)9780889866386
this paper research on how to select a subtree with exactly k leaves and a diameter of at most 1, which minimizes the distance from the farthest vertex to the subtree. We call such a subtree (k, l)-center of a tree network. In this paper, an efficient parallel algorithm is proposed for finding a (k, l)-center of a tree network. this algorithm performs on the EREW PRAM in O(log n) time using O(n) work.
We have developed a distributed asynchronous Web based training system. In order to improve the scalability and robustness of this system, all contents and a function that scores user's answers are realized on mob...
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ISBN:
(纸本)9780889866386
We have developed a distributed asynchronous Web based training system. In order to improve the scalability and robustness of this system, all contents and a function that scores user's answers are realized on mobile agents. these agents are distributed to computers, and they can obtain using a P2P network that modified Content-Addressable Network. In this system, although entire services do not become impossible even if some computers break down, the problem that contents disappear occurs with an agent's disappearance. In this study, as a solution for this problem, backups of agents are distributed to computers. If a failure of a computer is detected, other computer will continue service using backups of the agents belonged to the computer. the developed algorithm is examined by experiments.
the efficient characterization of adaptive parallel applications is usually challenging due to their complexity and large problem size. Unlike traditional profiling approaches which target the tracing of events or det...
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ISBN:
(纸本)9780889866386
the efficient characterization of adaptive parallel applications is usually challenging due to their complexity and large problem size. Unlike traditional profiling approaches which target the tracing of events or determining performance parameters for subroutines, the approach described in this paper attempts to discover the inherent adaptivity of parallel applications mapped to the computation domain/mesh, which are independent of runtime environment, so as to aid in the performance tuning of parallel applications, especially dynamic load balancing and repartitioning. Our profiling scheme only requires one-time execution of the target program on any platform to generate a sequence of traces with timestamps. the traces can then be fed to simulations under various system configurations while independent of the real application. Preliminary experiments have been performed to evaluate the proposed profiling techniques.
Complex system design and analysis requires simulations with different views or domains. Multi-domain simulation models typically are a collection of simulation model integrated through various means. these concurrent...
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ISBN:
(纸本)9780889866386
Complex system design and analysis requires simulations with different views or domains. Multi-domain simulation models typically are a collection of simulation model integrated through various means. these concurrent models may be implemented to be closely integrated or distributed as parallel-distributed simulation or mix of the two. Performance of a coupled simulation between multiple domain models depends on various factors. Some of them are, integration backplane architecture, messaging schemes, sharing scheme, level of coupling, fidelity of domain models etc. Framework for Optimizing Multidomain Simulation (MSOMS) is a framework which can be used to estimate performance and effectiveness of integration methods under various scenarios. the framework is referred as meta-simulation, since it is a "simulation of a simulation". this paper captures formulation and demonstration of MSOMS. We compared two possible implementations of a multi-domain model using MSOMS as a case study.
A future is a parallel programming language construct that enables programmers to specify potentially asynchronous computations. We present and empirically evaluate a novel implementation of futures for Java. Our futu...
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ISBN:
(纸本)9780889866386
A future is a parallel programming language construct that enables programmers to specify potentially asynchronous computations. We present and empirically evaluate a novel implementation of futures for Java. Our futures implementation is a JVM extension that couples estimates of future computational granularity with underlying resource availability to enable automatic and adaptive decisions of when to spawn futures in parallel or to execute them sequentially. Our system builds from, combines. and extends (i) lazy task creation and (ii) a JVM sampling infrastructure previously used solely for dynamic and adaptive compilation. We empirically evaluate our system using different benchmarks, triggers for automatic spawning of futures, processor availability, and JVM configurations. We show that our future implementation for Java is efficient and scalable for fine-grained Java futures without requiring programmer intervention.
In a grid computing environment, dynamicity, and geographically distributed sites, make task scheduling problems challenging to solve. It is hard for a local site to obtain precise real-time information about other si...
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ISBN:
(纸本)9780889866386
In a grid computing environment, dynamicity, and geographically distributed sites, make task scheduling problems challenging to solve. It is hard for a local site to obtain precise real-time information about other sites given that specific information on a site such as load and computing resources may change rapidly. Moreover, in data grid environment, large scale data intensive applications make scheduling problems even more challenging since both computational and data storage resources must be taken into consideration. In this paper we propose an innovative peer-to-peer scheduler to solve these problems. this scheduler is distributed and scalable. We used simulation to evaluate the performance of the scheduler under different circumstances, such as different number of hops to search suitable sites and different number of incoming tasks. Results show that our scheduler can successfully schedule around 75% of incoming tasks within their deadlines in average. For computation-intensive tasks, it can successfully schedule more than 90% of incoming tasks.
the Replica Placement Problem (RPP) aims at selecting the nodes for duplicating data objects in order to optimize their access. Even though a lot of work already exists on RPP, the issue of implementing the resulting ...
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ISBN:
(纸本)9780889866386
the Replica Placement Problem (RPP) aims at selecting the nodes for duplicating data objects in order to optimize their access. Even though a lot of work already exists on RPP, the issue of implementing the resulting allocation scheme is typically overlooked. In this paper we introduce the Replica Transfer Scheduling Problem (RTSP), briefly stated as: given a network of servers with limited storage capacitv, a set of data objects and two replication schemes x(old) and X-new, find a schedule of object transfers and deletions for implementing X-old based on X-old with minimum communication cost. Given that this problem is NP-complete, we introduce several different heuristics to solve it, and evaluate them via simulations.
An efficient range query processing support is required for distributed Hash Table (DHT)-based P2P networks as consistent hashing destroys the inherent order of numeric keys. In this paper, we present a lightweight an...
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ISBN:
(纸本)9780889866386
An efficient range query processing support is required for distributed Hash Table (DHT)-based P2P networks as consistent hashing destroys the inherent order of numeric keys. In this paper, we present a lightweight and efficient mechanism, called Range Hash Tree (RHT), to support range queries on DHTs. In RHT, key space is partitioned into small ranges such that data items within one range can be stored on one node. To quickly resolve a range query, we introduce a scalable encoding algorithm that can represent the key space partitioning status with a small RHT Signature. Compared to other approaches, RHT provides a bounded query delay, which is independent of the size of range query and the number of matching data items. Our experiments show that RHT works efficiently on both uniform and much skewed data distributions.
the Multi-Level computing Architecture (MLCA) is a novel parallel System-on-a-Chip architecture targeted for multimedia applications. It features a top level controller that automatically extracts task level paralleli...
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ISBN:
(纸本)9780889866386
the Multi-Level computing Architecture (MLCA) is a novel parallel System-on-a-Chip architecture targeted for multimedia applications. It features a top level controller that automatically extracts task level parallelism using techniques similar to how instruction level parallelism is extracted by superscalar processors. this allows the MLCA to support a simple programming model that is similar to sequential programming. In order to assist programmers to easily and efficiently port multimedia applications to the MLCA programming model, a compilation environment is designed. this compilation environment enhances parallelism in MLCA programs by applying three simple code transformations that are based on known compiler optimizations. In this paper, we describe the MLCA architecture, its programming model, its compilation environment and an evaluation of its performance. Our experimental evaluation withthree real multimedia applications and an MLCA simulator shows that the MLCA is a viable architecture and scaling speedups can be obtained using the compilation environment with little programmer effort.
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