Using space-filling curves to partition unstructured finite element meshes is a widely applied strategy when it comes to distributing load among several computation nodes. Compared to more elaborated graph partitionin...
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Using space-filling curves to partition unstructured finite element meshes is a widely applied strategy when it comes to distributing load among several computation nodes. Compared to more elaborated graph partitioning packages, this geometric approach is relatively easy to implement and very fast. However, results are not expected to be as good as those of the latter. In this paper we present results of our experiments comparing the quality of partitionings computed with different types of space-filling curves to those generated withthe graph partitioning package Metis. (c) 2004 Elsevier B.V. All rights reserved.
this paper combines work done in the areas of Artificial Intelligence, Multimedia Systems and Coordination Programming to derive a framework for distributed Multimedia Systems based on asynchronous timed computations ...
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this paper combines work done in the areas of Artificial Intelligence, Multimedia Systems and Coordination Programming to derive a framework for distributed Multimedia Systems based on asynchronous timed computations expressed in a certain coordination formalism. More to the point, we propose the development of multimedia programming frameworks based on the declarative logic programming setting and in particular the framework of object-oriented timed concurrent constraint programming (OO-TCCP). the real-time extensions that have been proposed for the concurrent constraint programming framework are coupled withthe object-oriented and inheritance mechanisms that have been developed for logic programs yielding an integrated declarative environment for multimedia objects modelling, composition and synchronisation. Furthermore, we show how the framework can be implemented in the general-purpose coordination language MANIFOLD without the need for using special architectures or real-time languages. (c) 2004 Elsevier B.V. All rights reserved.
Modern systems have extended their complexity, administration and design become almost impossible duties. the most frequent performance problems can be identified in database systems and more specific in distributed o...
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作者：
Selikhov, AGermain, CRAS
SB ICMMG Supercomp Software Dept Novosibirsk 630090 Russia Univ Paris 11
LAL CNRS F-91898 Orsay France LRI
PCRI F-91405 Orsay France
Fault tolerant message passing environments protect parallel applications against node failures. Very large scale computing systems, ranging from large clusters to worldwide Global computing systems, require a high le...
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Fault tolerant message passing environments protect parallel applications against node failures. Very large scale computing systems, ranging from large clusters to worldwide Global computing systems, require a high level of fault tolerance in order to efficiently run parallel applications. the Channel Memory approach provides the infrastructure for scalable tolerance to simultaneous faults. Along with a specially designed checkpointing system and recovery protocol, this approach has resulted in the MPICH-V architecture. In this paper, we describe CMDE - a stand-alone distributed program system based on MPICH-V architecture and implementing an approach to tolerate faults of Channel Memories. (c) 2004 Elsevier B.V. All rights reserved.
We present a simulation tool to predict the behavior of single regions in dynamical probabilistic P systems with reduced size, that is, membrane systems with probability values associated to rules that dynamically cha...
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ISBN:
(纸本)0769524532
We present a simulation tool to predict the behavior of single regions in dynamical probabilistic P systems with reduced size, that is, membrane systems with probability values associated to rules that dynamically change during the evolution, where the number of objects whose evolution is analyzed is not greater than 2. the tool is based on the construction of a grid over the phase space of a region, which is then used to evaluate the mean displacement of each multiset in the grid and to build the vectorfield of that region. As a consequence, we can predict the local evolutions (i.e., the behavior of the system inside each membrane) for all possible choices of initial multisets. We show some applications of this method to investigate the dynamics of two simple abstract toy-systems and of the Lotka-Volterra model.
Many research studies have proposed analytical models to evaluate the performance of k-ary n-cubes with deterministic wormhole routing. Such models however have so far been confined to uniform traffic distributions. T...
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ISBN:
(纸本)0769523129
Many research studies have proposed analytical models to evaluate the performance of k-ary n-cubes with deterministic wormhole routing. Such models however have so far been confined to uniform traffic distributions. there has been hardly any model proposed that deal with non-uniform traffic distributions that could arise due to, for instance, the presence of hot-spots in the network. this paper proposes the first analytical model to predict message latency in k-ary n-cubes with deterministic routing in the presence of hot-spots. the validity of the model is demonstrated by comparing analytical results withthose obtained through extensive simulation experiments.
Inference of large phylogenetic trees using statistical methods is computationally extremely expensive. thus, progress is primarily achieved via algorithmic innovation rather than by brute-force allocation of availabl...
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Inference of large phylogenetic trees using statistical methods is computationally extremely expensive. thus, progress is primarily achieved via algorithmic innovation rather than by brute-force allocation of available computational ressources. We describe simple heuristics which yield accurate trees for synthetic (simulated) as well as real data and significantly improve execution time. the heuristics are implemented in a sequential program (RAxML) and a novel non-deterministic distributed algorithm (DRAxML@home). We implemented an MPI-based and a http-based distributed prototype of this algorithm and used DRAxML@home to infer trees comprising 1000 and 2025 organisms on LINUX PC clusters. (c) 2004 Elsevier B.V. All rights reserved.
Enabling high performance, persistent mobile computing has recently become a very active research area. the widespread popularity of mobile computing devices, such as laptops, handheld devices and cell phones, as well...
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ISBN:
(纸本)0769523129
Enabling high performance, persistent mobile computing has recently become a very active research area. the widespread popularity of mobile computing devices, such as laptops, handheld devices and cell phones, as well as the recent advances in wireless communication technologies are the principal motivators of this research area. However, battery energy limitation is the main challenge towards enabling persistent mobile computing. Several hardware based techniques have been proposed;this has led to more energy-efficient systems. Nevertheless, the problem still remains and there is a consensus that software based techniques have the potential to reduce energy demand and contribute to solve the problem. In this paper, we look into the problem of distributing computational tasks amongst a set of mobile computing devices in a Mobile wireless Ad hoc NETwork (MANET) in such a way that conserves energy and improves performance. In such a distributed environment, the assignment of computational tasks to different devices and the order of their execution play a vital role in energy conservation and performance improvement. the main contributions of this paper are formulating a novel energy-aware scheduling problem and proposing a heuristic algorithm to solve it. Our scheduling algorithm schedules a set of computational tasks, which may have dependencies and communication, into a set of heterogeneous processors in such a way that minimizes boththe total consumed energy and the makespan (i.e., the time by which all tasks complete their execution). Experiments show that significant improvement can be achieved by using our scheduler.
Data replication is a common method used to improve the performance of data access in distributed systems. In this paper, two dynamic replication algorithms, Simple Bottom-Up (SBU) and Aggregate Bottom-Up (ABU), are p...
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Data replication is a common method used to improve the performance of data access in distributed systems. In this paper, two dynamic replication algorithms, Simple Bottom-Up (SBU) and Aggregate Bottom-Up (ABU), are proposed for the multitier Data Grid. A multi-tier Data Grid simulator called DRepSim is developed for studying the performances of the dynamic replication algorithms. the simulation results show that both algorithms can reduce the average response time of data access greatly compared to the static replication method. ABU can achieve great performance improvements for all access patterns even if the available storage size of the replication server is very small. Comparing the two algorithms to Fast Spread dynamic replication strategy, ABU proves to be superior. As for SBU, although the average response time of Fast Spread is better in most cases, Fast Spread's replication frequency is too high to be applicable in the real world. (c) 2004 Elsevier B.V. All rights reserved.
Using space-filling curves to partition unstructured finite element meshes is a widely applied strategy when it comes to distributing load among several computation nodes. Compared to more elaborated graph partitionin...
详细信息
Using space-filling curves to partition unstructured finite element meshes is a widely applied strategy when it comes to distributing load among several computation nodes. Compared to more elaborated graph partitioning packages, this geometric approach is relatively easy to implement and very fast. However, results are not expected to be as good as those of the latter. In this paper we present results of our experiments comparing the quality of partitionings computed with different types of space-filling curves to those generated withthe graph partitioning package Metis. (c) 2004 Elsevier B.V. All rights reserved.
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