Numerical methods based on interval arithmetic ore efficient means to reliably solve nonlinear systems of equations. Algorithm bc3revise is an interval method that tightens variables' domains by enforcing a proper...
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ISBN:
(纸本)9780769534435
Numerical methods based on interval arithmetic ore efficient means to reliably solve nonlinear systems of equations. Algorithm bc3revise is an interval method that tightens variables' domains by enforcing a property called box consistency. It has been successfully used on difficult problems whose solving eluded traditional numerical methods. We present a new algorithm to enforce box consistency that is simpler than bc3revise, faster and easily data parallelizable. A parallel implementation with Intel SSE2 SIMD instructions shows that an increase in performance of up to an order of magnitude and more is achievable.
Metacube is an attractive, hypercube-like interconnection network that can connect an extremely large number of nodes with a small node degree while keeping a relatively short diamemter A Metacube MC(k, m) connects 2(...
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ISBN:
(纸本)9780769534435
Metacube is an attractive, hypercube-like interconnection network that can connect an extremely large number of nodes with a small node degree while keeping a relatively short diamemter A Metacube MC(k, m) connects 2(2km+k) nodes with only k + m links per node. Metacube can be used to build parallelcomputing systems of very large scale with a small number of links per node. In this paper we propose a new presentation of Metacube for algorithmic design on Metacube. Based on the new presentation, we give an efficient algorithm for parallel prefix computation on Metacubes that runs in 2(k)m(k + 1) + k communication steps and 2(k+1) m + 2k computation steps.
The development of numerical simulation software tools for the solution of real-world problems usually calls for domain experts in modeling. The GraPA framework,, as an abstraction layer on top of hardware characteris...
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ISBN:
(纸本)9780769534435
The development of numerical simulation software tools for the solution of real-world problems usually calls for domain experts in modeling. The GraPA framework,, as an abstraction layer on top of hardware characteristics, supports modelers in two respects: one is the built-in support for co-processing of multiple models and the other is the generically delivered high performance achieved by implementing concurrency features of multicore and distributed memory architectures. Technically, GraPA is designed as a C++ template framework, where the modeler's data structures and algorithms instantiate the framework. Using this approach, we handle parallel processing of lock-free data structures and message passing transperently to the modelers. In this paper, we report on the status of the implementation of GraPA and on its performance characteristics.
This paper presents a novel video service system DCSVS (distributed Collaborative Set-top-box Video Service), which encompasses several practical and effective solutions to both Live and VoD (Video-on-Demand) services...
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ISBN:
(纸本)9780769534435
This paper presents a novel video service system DCSVS (distributed Collaborative Set-top-box Video Service), which encompasses several practical and effective solutions to both Live and VoD (Video-on-Demand) services. DCSVS is established on an overlay DHT (distributed Hash Table) network, which improves Kademlia Protocol to fit for Real-Time application. We use several types of Pre-Fetching to enhance continuity rate of VoD service, and we employ an effective scheduling algorithm based on transferring priorities. We design the Inner-First and Proxy-Forward strategy to relieve transferring failure, and we use Window-based storage and hashing to achieve better system performance. Both theoretical analysis and experimental results show that strategies in DCSVS perform well in terms of efficiency and robustness, and could maintain a fine state and scalability in large-scale networking.
In recent years, wireless sensor networks have received great interest with rapid developments in both hardware and software aspects. However, there is always a problem with limited energy supply for the tiny sensor n...
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ISBN:
(纸本)9780769534435
In recent years, wireless sensor networks have received great interest with rapid developments in both hardware and software aspects. However, there is always a problem with limited energy supply for the tiny sensor node. In wireless imaging sensor network in which imaging devices are utilized, the bottleneck of energy consumption efficiency is even more serious. The main activities of such imaging networks are related to image data transmission over wireless channel. Therefore it is necessary to seek a good balance between the image quality and energy conservation. We propose an energy-efficient control scheme based on recent dynamic range coding techniques. The simulation results are presented with emphasis on prolonging the sensor network lifetime.
Scheduling tasks onto the processors of a parallel system is a crucial part of program parallelisation. Due to the NP-hard nature of the task scheduling problem, scheduling algorithms are based on heuristics that try ...
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ISBN:
(纸本)9780769534435
Scheduling tasks onto the processors of a parallel system is a crucial part of program parallelisation. Due to the NP-hard nature of the task scheduling problem, scheduling algorithms are based on heuristics that try to produce good rather than optimal schedules. Nevertheless, in certain situations it is desirable to have optimal schedules, for example for time critical systems or to evaluate scheduling heuristics. This paper investigates the task scheduling problem using A* search algorithm. The A* scheduling algorithm implemented can produce optimal schedules in reasonable time for small to medium sized task graphs. In comparison to a previous approach, the here presented A* scheduling algorithm has a significantly reduced search space due to a much improved cost function f (s) and additional pruning techniques. Last but not least, the experimental results show that the proposed A* scheduling algorithm significantly outperforms the previous approach.
In update intensive applications, main memory database systems produce large volume of log records, it is critical to write out the log records efficiently to speedup transaction processing. We propose a parallel reco...
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ISBN:
(纸本)9780769534435
In update intensive applications, main memory database systems produce large volume of log records, it is critical to write out the log records efficiently to speedup transaction processing. We propose a parallel recovery scheme based on XOR differential logging for main memory database systems in such environments. Some NVRAM is used to temporarily hold log records and decouple transaction committing from disk writes, inherited parallelism properties of differential logging are exploited to accelerate log flushing by using multiple log disks. During recovery, log records are loaded from multiple log disks and applied to data partition in time without the need of reordering according to serialization order, total recovery time is cut down. The scheme employs a data partition based consistent checkpointing method. The log records are classified according to IDs of data partitions accessed. Data partitions are recovered according to loading priorities computed from update frequencies and transaction waiting times, data access demands of new transactions coming after failure recovery are given attention immediately, thus the scheme provides system availability during recovery, which is of importance for large scale main memory database systems.
Copyright and Reprint Permissions: Abstracting is permitted with credit to the source. Libraries may photocopy beyond the limits of US copyright law, for private use of patrons, those articles in this volume that carr...
Copyright and Reprint Permissions: Abstracting is permitted with credit to the source. Libraries may photocopy beyond the limits of US copyright law, for private use of patrons, those articles in this volume that carry a code at the bottom of the first page, provided that the per-copy fee indicated in the code is paid through the Copyright Clearance Center. The papers in this book comprise the proceedings of the meeting mentioned on the cover and title page. They reflect the authors' opinions and, in the interests of timely dissemination, are published as presented and without change. Their inclusion in this publication does not necessarily constitute endorsement by the editors or the Institute of Electrical and Electronics Engineers, Inc.
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