Despite the well known advantages of distributed processing for intensive computations like simulation, frameworks often fail to exploit them. A distributed simulation is harder to develop than a sequential one, becau...
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ISBN:
(纸本)9780889866379
Despite the well known advantages of distributed processing for intensive computations like simulation, frameworks often fail to exploit them. A distributed simulation is harder to develop than a sequential one, because it is necessary to interface and map activities to processors and handle the ensuing communication and synchronization problems. Very often the designer has to explicitly specify extra information concerning distribution for the framework to make an effort to exploit parallelism. This paper presents Automated distributed Simulation (ADS), which allows the designer to forget about distribution concerns while benefiting from the advantages. ADS relies on the actor formalism. It is realized as an open source implementation for the Ptolemy II simulation framework. Experiments compare different topologies, granularities and number of blocks, achieving linear speedups for practical cases. We implement pipelining techniques so iterative models with purely sequential topologies can benefit from ADS.
Data mining across different companies, organizations, online shops, or the likes is necessary so as to discover valuable shared patterns, associations, trends, or dependencies in their shared data. Privacy, however, ...
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ISBN:
(纸本)9780889866379
Data mining across different companies, organizations, online shops, or the likes is necessary so as to discover valuable shared patterns, associations, trends, or dependencies in their shared data. Privacy, however, is a concern. In many situations it is required that data mining should be conducted without any privacy being violated. In response to this requirement, this paper proposes an effective distributed privacy-preserving data mining approach called CRDM (Collusion-Resistant Data Mining). CRDM is characterized by its ability to resist the collusion. Let the number of sites participating in data mining be M. Unless the number of colluding sites is not less than M - 1, privacy cannot be violated. Results of both analytical and experimental performance study demonstrated the effectiveness of CRDM.
Overlay multicast protocol constructs a virtual mesh spanning all member nodes of a multicast group and employs standard unicast routing to fulfill multicast functionality on application layer. The advantages of this ...
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ISBN:
(纸本)9780889866386
Overlay multicast protocol constructs a virtual mesh spanning all member nodes of a multicast group and employs standard unicast routing to fulfill multicast functionality on application layer. The advantages of this approach are simplicity and flexibility. However, efficiency and stability are the issues that must be addressed as the size of the multicast group grows in the mobile ad hoc networks (MANETs). In this paper, we propose an effective structure for overlay multicast to solve these problems in MANETs. Instead of using a spanning tree on the virtual mesh, we adopt a simple structure called MCore for multicast. An MCore is a path that minimizes the sum of the distances of all vertices to the path plus the length of the path. The MCore is more stable and easier to maintain than the spanning tree in MANETs. The simulation results show that our approach handles the flexibility and mobility issues in overlay multicast protocols effectively for large multicast group size.
Graphics processing units(GPUs) are starting to play an increasingly important role in non-graphical applications which are highly parallelisable. With the latest graphics cards boasting a theoretical 165GFlops and 54...
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ISBN:
(纸本)9780889866379
Graphics processing units(GPUs) are starting to play an increasingly important role in non-graphical applications which are highly parallelisable. With the latest graphics cards boasting a theoretical 165GFlops and 54GB/s memory bandwidth spread across 48 ALUs it is easy to see why. The GPU architecture is particularly suited to the parallel stream processing paradigm of low levels of data dependency, high data to instruction ratio and predictable memory access patterns. One largely ignored, yet key, bottleneck for this type of processing on GPUs is both download and readback transfer performance to and from the graphics card. Existing tools provide great developer assistance in many areas of GPU application development, though provide very limited assistance in gaining the best bi-directional data transfer performance. In this paper, we discuss these limitations and present new investigative tools which allow general purpose processing GPU developers to explore the complex array of configuration states which affect both the download and readback performance.
The following topics are dealt with: image, speech and signal processing; software engineering; operating system and compiler; data mining and knowledge discovery; machine learning, natural language, and neural networ...
The following topics are dealt with: image, speech and signal processing; software engineering; operating system and compiler; data mining and knowledge discovery; machine learning, natural language, and neural networks; software architecture; Web and multimedia; voice over IP; cryptography and network security; wireless networks; parallel and distributedcomputing; adhoc networks and routing protocols; learning system; learning system; meeting system; positioning and routing; and QOS and energy efficiency.
In this paper, we study effects of hotspots on throughput in mobile ad hoc networks. A hotspot is a node causing network congestion. We first describe three types of hotspots: (a) delay-based, (b) energy-based, and (c...
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ISBN:
(纸本)9780889866379
In this paper, we study effects of hotspots on throughput in mobile ad hoc networks. A hotspot is a node causing network congestion. We first describe three types of hotspots: (a) delay-based, (b) energy-based, and (c) preferential-mobility-based. Nodes may exhibit delay or energy problems if an accident occurs in mobile ad hoc networks. Furthermore, certain nodes may be attractive to other nodes to follow them. Different types of hotspots may have different effects on network performance. We discuss effects of hotspots by various properties such as number of hotspots, clustering, placement, degree, etc. Powerful relays are useful to improve performance degradation due to hotspots. At last, we discuss performance of hotspots with powerful relays.
This paper presents some numerical evaluations of parallel double Divide and Conquer for singular value decomposition. For eigenvalue decomposition and singular value decomposition, double Divide and Conquer was recen...
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ISBN:
(纸本)9780889866379
This paper presents some numerical evaluations of parallel double Divide and Conquer for singular value decomposition. For eigenvalue decomposition and singular value decomposition, double Divide and Conquer was recently proposed. It rst computes eigen/singular values by a compact version of Divide and Conquer. The corresponding eigen/singular vectors are then computed by twisted factorization. The speed and accuracy of double Divide and Conquer are as good or even better than standard algorithms such as QR and the original Divide and Conquer. In addition, it is expected that double Divide and Conquer has great parallelism because each step is theoretically parallel and heavy communication is not required. This paper numerically evaluates a parallel implementation of dDC with MPI on some large scale problems using a distributed memory architecture and a massively parallel super computer, especially in terms of parallelism. It shows high scalability and super linear speed-up is observed in some cases.
Overlapping of communication and computation has been intuitively used for a long time to improve the performance of parallelcomputing. One of approaches which allow increasing the ability of this overlapping is to u...
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ISBN:
(纸本)0889865701
Overlapping of communication and computation has been intuitively used for a long time to improve the performance of parallelcomputing. One of approaches which allow increasing the ability of this overlapping is to use active message. This paper presents the study of the overlapping communication/computation performance of INUKTITUT, an interface based on active message. This interface allows effectively and easily carrying of parallel programming high-level environments such as Athapascan on the computing clusters. We will present in this paper different performance evaluations of INUKTITUT on overlapping potential.
In a Grid environment the main components that manage the job workflow life are the Grid Resource Layer, the Grid Information System and the Grid Information Data Model. Until now, only some of the known computational...
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ISBN:
(纸本)088986568X
In a Grid environment the main components that manage the job workflow life are the Grid Resource Layer, the Grid Information System and the Grid Information Data Model. Until now, only some of the known computational resources, such as a hardware machines and a batch queueing system, have been take into account as valid Resource Framework Layer instances. However many types of virtual computing machines exist, such as a Java Virtual Machine, a parallel Virtual Machine and a Data Source Engine. The actual representation of a Grid resource in the Grid Information System and Data Model concerns only hardware computing machines. We argue that a Data Source Engine is a valid instance for a Grid computing model. Then we define a new Grid element that enables the access to a Data Source Engine and a Data Source, totally integrated with the Grid Monitoring and Discovery System and Resource Broker.
Genetic algorithrms have been applied to solve the 2-page drawing problem successfully, but they work with one global population, so the search time and space are limited. parallelization provides an attractive prospe...
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ISBN:
(纸本)088986568X
Genetic algorithrms have been applied to solve the 2-page drawing problem successfully, but they work with one global population, so the search time and space are limited. parallelization provides an attractive prospect in improving the efficiency and solution quality of genetic algorithms. One of the most popular tools for parallelcomputing is Message Passing Interface (AIPI). In this paper, we present four island models of parallel Genetic Algorithms with MPI: island models with linear, grid, random graph topologies and island model with periodical synchronisation. We compare their efficiency and quality of solutions for the 2-page drawing problem on a variety of graphs.
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