Aggregate Function - Explore the Science & Experts | ideXlab

Scan Science and Technology

Contact Leading Edge Experts & Companies

Aggregate Function

The Experts below are selected from a list of 48630 Experts worldwide ranked by ideXlab platform

Aggregate Function – Free Register to Access Experts & Abstracts

Daoxu Chen – One of the best experts on this subject based on the ideXlab platform.

  • a qos aware service selection algorithm for multimedia service overlay networks
    International Conference on Parallel and Distributed Systems, 2007
    Co-Authors: Yilin Wang, Daoxu Chen

    Abstract:

    Multimedia applications are becoming more and more popular on today’s Internet. Given the enormous development costs and less flexibility, traditional monolithic based approaches are not suitable for building large-scale multimedia systems. By composing of distributed, autonomous services dynamically to provide more complex tasks, service composition provides an attractive way for building large-scale Internet applications. So, multimedia service composition provides a viable solution to large-scale complex multimedia systems. One of the challenging issues of multimedia service composition is how to find service paths to route the data flows through while meeting the applications’ resource requirements and specific QoS constraints. However, QoS-aware service routing problem is typically NP-hard. In this paper, we propose a heuristic algorithm named greedy-EF to solve this problem more effectively. More specially, greedy-EF uses an Aggregate Function to evaluate the QoS conditions for each service instance, and a hop-by-hop service selection approach to explore the proper service path. Simulations show that greedy-EF algorithm can achieve desired QoS assurances as well as load balancing in multimedia service overlay networks.

  • ICPADS – A QoS-aware service selection algorithm for multimedia service overlay networks
    2007 International Conference on Parallel and Distributed Systems, 2007
    Co-Authors: Yilin Wang, Daoxu Chen

    Abstract:

    Multimedia applications are becoming more and more popular on today’s Internet. Given the enormous development costs and less flexibility, traditional monolithic based approaches are not suitable for building large-scale multimedia systems. By composing of distributed, autonomous services dynamically to provide more complex tasks, service composition provides an attractive way for building large-scale Internet applications. So, multimedia service composition provides a viable solution to large-scale complex multimedia systems. One of the challenging issues of multimedia service composition is how to find service paths to route the data flows through while meeting the applications’ resource requirements and specific QoS constraints. However, QoS-aware service routing problem is typically NP-hard. In this paper, we propose a heuristic algorithm named greedy-EF to solve this problem more effectively. More specially, greedy-EF uses an Aggregate Function to evaluate the QoS conditions for each service instance, and a hop-by-hop service selection approach to explore the proper service path. Simulations show that greedy-EF algorithm can achieve desired QoS assurances as well as load balancing in multimedia service overlay networks.

Yilin Wang – One of the best experts on this subject based on the ideXlab platform.

  • a qos aware service selection algorithm for multimedia service overlay networks
    International Conference on Parallel and Distributed Systems, 2007
    Co-Authors: Yilin Wang, Daoxu Chen

    Abstract:

    Multimedia applications are becoming more and more popular on today’s Internet. Given the enormous development costs and less flexibility, traditional monolithic based approaches are not suitable for building large-scale multimedia systems. By composing of distributed, autonomous services dynamically to provide more complex tasks, service composition provides an attractive way for building large-scale Internet applications. So, multimedia service composition provides a viable solution to large-scale complex multimedia systems. One of the challenging issues of multimedia service composition is how to find service paths to route the data flows through while meeting the applications’ resource requirements and specific QoS constraints. However, QoS-aware service routing problem is typically NP-hard. In this paper, we propose a heuristic algorithm named greedy-EF to solve this problem more effectively. More specially, greedy-EF uses an Aggregate Function to evaluate the QoS conditions for each service instance, and a hop-by-hop service selection approach to explore the proper service path. Simulations show that greedy-EF algorithm can achieve desired QoS assurances as well as load balancing in multimedia service overlay networks.

  • ICPADS – A QoS-aware service selection algorithm for multimedia service overlay networks
    2007 International Conference on Parallel and Distributed Systems, 2007
    Co-Authors: Yilin Wang, Daoxu Chen

    Abstract:

    Multimedia applications are becoming more and more popular on today’s Internet. Given the enormous development costs and less flexibility, traditional monolithic based approaches are not suitable for building large-scale multimedia systems. By composing of distributed, autonomous services dynamically to provide more complex tasks, service composition provides an attractive way for building large-scale Internet applications. So, multimedia service composition provides a viable solution to large-scale complex multimedia systems. One of the challenging issues of multimedia service composition is how to find service paths to route the data flows through while meeting the applications’ resource requirements and specific QoS constraints. However, QoS-aware service routing problem is typically NP-hard. In this paper, we propose a heuristic algorithm named greedy-EF to solve this problem more effectively. More specially, greedy-EF uses an Aggregate Function to evaluate the QoS conditions for each service instance, and a hop-by-hop service selection approach to explore the proper service path. Simulations show that greedy-EF algorithm can achieve desired QoS assurances as well as load balancing in multimedia service overlay networks.

Henry G Dietz – One of the best experts on this subject based on the ideXlab platform.

  • Chip multiprocessors with on-chip Aggregate Function network
    , 2009
    Co-Authors: Samuel P. Midkiff, Henry G Dietz, Soohong P. Kim

    Abstract:

    State-of-the-art on-chip networks and block-based cache coherence protocols used in cache-coherent shared-memory Chip MultiProcessors (CMPs) are inefficient for collective operations across cores. Performance of CMPs can be seriously degraded by the multitude of memory requests and coherence messages required to implement each collective operation. This thesis presents a CMP-AFN architecture and Instruction Set Architecture (ISA) extensions that augment a conventional shared-memory CMP with a tightly-integrated Aggregate Function Network (AFN) that implements low-latency collective operations without using or interfering with the memory hierarchy. For a modest increase in circuit complexity, traffic within a CMP’s internal network is dramatically reduced, improving the performance of caches and reducing power consumption. Full system simulations of 16-core CMPs show a CMP-AFN outperforms the reference design significantly, eliminating up to 52% of memory accesses and up to 73% of private L1 data cache misses in both the EPCC OpenMP microbenchmarks and SPEC OMP benchmarks.

  • LCPC – Hardware support for OpenMP collective operations
    Languages and Compilers for Parallel Computing, 2009
    Co-Authors: Samuel P. Midkiff, Henry G Dietz

    Abstract:

    Efficient implementation of OpenMP collective operations (e.g. barriers and reductions) is essential for good performance from OpenMP programs. State-of-the-art on-chip networks and block-based cache coherence protocols used in shared memory Chip MultiProcessors (CMPs) are inefficient for implementing these collective operations. The performance of CMPs can be seriously degraded by the multitude of memory requests and coherence messages required to implement collective operations. To provide efficient support for OpenMP collective operations, this paper presents a CMP-AFN architecture and Instruction Set Architecture (ISA) extensions that augment a conventional shared-memory CMP with a tightly-integrated Aggregate Function Network (AFN) that implements low-latency collectives without using or interfering with the memory hierarchy. For a modest increase in circuit complexity, traffic within a CMP’s internal network is dramatically reduced, improving the performance of caches and reducing power consumption. Full system simulations of 16-core CMPs show a CMP-AFN outperforms the reference design significantly, eliminating more than 60% of memory accesses and more than 70% of private L1 data cache misses in both the EPCC OpenMP microbenchmarks and SPEC OMP benchmarks.

  • LCPC – The Aggregate Function API: It’s Not Just for PAPERS Anymore
    Languages and Compilers for Parallel Computing, 1998
    Co-Authors: Henry G Dietz, Timothy Mattox, G. Krishnamurthy

    Abstract:

    The concept of data parallelism is a pervasive force throughout parallel processing. Although a certain level of processing-element autonomy can help performance, the fact is that many parallele algorithms, applications, and compiler analysis techniques focus on identifying a set of data objects that can be processed using loosely synchronous parallelism. Thus, it is not surprising that a large number of communication libraries support at least a few synchronized Aggregate operations on data. The Aggregate Function Application Program Interface (AFAPI) library was initially designed to be a portable high-level interface to the various types of PAPERS cluster hardware, so one would expect it to work well using this custom hardware, and it does work well. In this paper, we show that the AFAPI is also an efficient programming model for other types of parallel systems, especially shared memory multiprocessors. For many operations AFAPI can outperform threads libraries and other more traditional shared memory programming models.