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1.
混合类型多媒体负载访问存储系统是一个复杂的过程,不同类型的多媒体应用要求存储系统提供不同的服务质量保证.存储系统需要一个有效的访问控制算法,为尽可能多的多媒体应用提供保证服务质量的服务.对混合类型多媒体负载访问存储系统的访问控制问题进行了系统的研究:定义多媒体应用访问存储系统的服务质量参数;建立并发多媒体应用的汇聚负载模型;推导出混合类型多媒体负载的访问控制约束条件;实现相应的统计学访问控制算法.仿真实验的结果表明,新的存储系统访问控制算法是有效的,并具有相当高的精确度.  相似文献   

2.
在高性能计算程序对海量分布存储数据的操控中,有效的数据管理很重要。该文提出一个新的高性能分布计算的数据管理与优化系统,它包含一个元数据管理系统和存储系统,提供一个容易使用且能自动进行存储访问优化的平台。该平台采用的多存储资源体系结构能够满足性能和存储容量需求,并能自适应地利用当前的I/O优化方法。  相似文献   

3.
介绍了神经网络计算平台在网格上的架构。由于神经网络应用环境的复杂性及要求处理大量数据的问题,从而神经网络计算需要超强的计算能力,因此在神经网络计算平台中引入了网格的思想,力图建立一个基于网格的神经网络计算平台。平台使用Globus工具,采用了统一控制和完全托管的思想。鉴于神经网络算法的复杂性和大数据量,神经计算算法在网格上进行适合各自特性的分解。  相似文献   

4.
基于SAN系统数据密集型程序的性能分析   总被引:1,自引:0,他引:1  
数据密集型应用如多媒体、数据库等等的大规模发展对存储系统提出更高的要求.与之相适应的是以SAN为代表的存储网络改变了存储系统完全依赖于主机的模式,整体上提高了存储系统性能、可用性、可扩展性.本文在研究整个SAN存储系统结构的基础上,通过分析和估计SAN系统的各个部分性能,结合数据密集型程序的I/O统计特性,估计各种I/O请求的平均响应时间,说明在SAN系统平台上I/O密集型程序的设计要求,为进一步开发大规模存储网络管理和应用软件打下基础.  相似文献   

5.
基于自组织的鲁棒非线性维数约减算法   总被引:4,自引:0,他引:4  
现有的非线性维数约减算法需要求解大尺度特征值问题.由于特征值问题至少二次的计算复杂性,这类算法在大样本集上的应用较受限制.此外,现有算法的全局优化机制对于噪声较为敏感,且需要考虑“病态矩阵”的计算精度问题.提出时间复杂性为O(NlogN)的自组织非线性维数约减算法SIE.SIE的主要计算过程是局域的,可提高算法抗噪性、回避病态矩阵的计算精度问题.仿真表明,对于无噪数据和含噪数据,SIE均可获得优化或近似优化的重构质量.  相似文献   

6.
垃圾回收有效地减轻了编程人员的负担、优化了程序的设计,在基于弱一致性模型的分布式共享存储系统中进行自动垃圾回收是非常困难的和低效的,本文提出了一种基于跟踪策略的实时分布式垃圾回收算法--RRDGC,使得各节点回收进程可以和应用程序并发执行,同时有效减少了弱一致性模型下额外的通信开销,降低了程序的响应时间.算法确保了垃圾回收的正确性和有效性,体现了增量和实时性的特点.最后通过仿真实验对比论证了该算法的正确性和高效性.  相似文献   

7.
程序复杂性度量的一种新方法   总被引:5,自引:1,他引:5  
通过分析传统的程序复杂性度量方法的不足之处,首先提出了一种基于程序分解机制的路径复杂性度量方法,然后给出了计算路径复杂度的算法,最后给出了实例。新的度量方法指出了一个程序需要的完全测试路径数目。  相似文献   

8.
磁盘存储系统节能技术研究综述   总被引:1,自引:0,他引:1  
目前磁盘是构成存储系统的重要组成部分,在存储系统总能耗中磁盘能耗占了大部分.因此磁盘存储系统的高能耗问题受到越来越多研究人员的关注.综述了磁盘存储系统从磁盘到存储系统各个层次的能耗研究进展和现状,同时对各种典型节能方法从原理、实现机制和评测手段等诸方面进行了分析和讨论,并对比分析和总结了各种节能技术的适应环境.结合海量存储系统负载特征的复杂性和应用环境的复杂性等特点,指出了磁盘存储系统节能技术的未来研究方向.  相似文献   

9.
在云计算环境下分布式存储系统中,通常采用副本技术保证存储系统的可用性和可靠性,放置策略是副本技术的一个关键问题。针对现有副本放置策略中存在的副本访问开销大的问题,提出一种基于离散型萤火虫优化的副本放置算法。考虑副本放置对用户访问性能的影响,对其建立数学模型,计算萤火虫位置的适应度函数,并朝着荧光素值最大即最优值移动,进而得到合适的副本放置节点。通过仿真实验评估提出的方法,并与基于蚁群算法的副本放置策略进行比较。实验结果证明该算法能够选择合适的副本放置节点,具有较好的收敛性,并有效地降低存储系统的副本访问开销。  相似文献   

10.
考虑库存余材利用的杆材下料方案   总被引:2,自引:0,他引:2  
本文应用典型的杆材下料算法(如列生成算法),提出一个考虑库存余材利用的杆材下料方案,在不增加计算复杂性情况下,解决更切实际的杆材下料问题。  相似文献   

11.
The implementations of the Viterbi algorithm (VA) and the interacting multiple model (IMM) algorithm on a shared-bus and shared-memory multiple-input multiple-data (MIMD) multiprocessor are discussed. The computational complexity as well as the speedup and efficiency are examined in detail. It is shown that the computational complexity of the parallel implementation of these algorithms is about the same in both memory space and processing time categories. Efficiency with P processors is about 1-1/P for small P and is expected to be relatively high for large P, especially when many filters and large state and measurement vectors are considered  相似文献   

12.

The neighborhood problem appears in many applications of computational geometry, computational mechanics, etc. In all these situations, the main requirement for a competitive implementation is performance, which can only be attained in modern hardware by exploiting parallelism. However, whereas the performance of serial algorithms is fairly predictable, that of parallel methods depends on delicate issues that have a huge impact (cache memory, cache misses, memory alignment, etc.), but are not easy to control. Even if there is not a simple approach to deal with these factors in shared-memory architectures, it is quite convenient to program parallel algorithms where the data are segregated on a per-thread basis. With this objective in mind, we propose a strategy to develop parallel algorithms based on a two-level design, and apply it to efficiently solve the nearest neighborhood problem. At a higher level, the proposed methods orchestrate the parallel algorithm and split the space into cells stored in a hash table; at the lower level, our methods hold serial search algorithms that are completely agnostic to the high-level counterpart. Using this strategy, we have developed a library combining different serial and parallel algorithms, optimized them, and assessed their performance. The analysis carried out allows to better understand the main bottlenecks in the algorithmic solution of the nearest neighborhood problem and come out with very fast implementations that improve existing available software.

  相似文献   

13.
王鑫  张铭 《计算机应用研究》2023,40(6):1745-1749
针对应用普通卷积结构的卷积计算复杂度较高、计算量与参数量较大的问题,提出以国产SW26010P众核处理器为平台的并行分组卷积算法。核心思想是利用独特的数据布局,通过多核映射处理进行并行计算。实验测试结果表明,与单核串行算法相比,使用该并行分组卷积算法可以获得79.5的最高加速比及186.7MFLOPS的最大有效算力。通过SIMD指令对并行分组卷积算法进行数据并行优化后,与使用优化前的并行分组卷积算法相比,可以获得10.2的最高加速比。  相似文献   

14.
一些文献认为Hughes-Hartogs比特分配算法在向多个子载波分配比特时,运算复杂度太大、速度太慢,实时性差.鲜有文献对它的运算量进行具体的分析.文中对Hughes-Hartogs比特分配算法的运算量进行了理论分析,得出了衡量它的运算量的方法.并在有线信道双绞线模型下,通过Matlab仿真,从发送总比特数和运算量两个方面,比较了Hughes-Hartogs算法与最优化的贪心算法的性能,得出了可用发送功率和量化间隔对Hughes-Hartogs算法性能的影响,以及怎样选择合适的参数既使Hughes-Hartogs算法的运算复杂度尽量小又使发送总比特数尽量大.并提出算法的改进方案,可以看到改进后的算法能够满足实时应用的需求.  相似文献   

15.
The development of intelligent transportation systems (ITS) and the resulting need for the solution of a variety of dynamic traffic network models and management problems require faster‐than‐real‐time computation of shortest path problems in dynamic networks. Recently, a sequential algorithm was developed to compute shortest paths in discrete time dynamic networks from all nodes and all departure times to one destination node. The algorithm is known as algorithm DOT and has an optimal worst‐case running‐time complexity. This implies that no algorithm with a better worst‐case computational complexity can be discovered. Consequently, in order to derive algorithms to solve all‐to‐one shortest path problems in dynamic networks, one would need to explore avenues other than the design of sequential solution algorithms only. The use of commercially‐available high‐performance computing platforms to develop parallel implementations of sequential algorithms is an example of such avenue. This paper reports on the design, implementation, and computational testing of parallel dynamic shortest path algorithms. We develop two shared‐memory and two message‐passing dynamic shortest path algorithm implementations, which are derived from algorithm DOT using the following parallelization strategies: decomposition by destination and decomposition by transportation network topology. The algorithms are coded using two types of parallel computing environments: a message‐passing environment based on the parallel virtual machine (PVM) library and a multi‐threading environment based on the SUN Microsystems Multi‐Threads (MT) library. We also develop a time‐based parallel version of algorithm DOT for the case of minimum time paths in FIFO networks, and a theoretical parallelization of algorithm DOT on an ‘ideal’ theoretical parallel machine. Performances of the implementations are analyzed and evaluated using large transportation networks, and two types of parallel computing platforms: a distributed network of Unix workstations and a SUN shared‐memory machine containing eight processors. Satisfactory speed‐ups in the running time of sequential algorithms are achieved, in particular for shared‐memory machines. Numerical results indicate that shared‐memory computers constitute the most appropriate type of parallel computing platforms for the computation of dynamic shortest paths for real‐time ITS applications.  相似文献   

16.
针对在时间和空间上都具有高计算成本的长序列数据库,一个更有效和更紧凑且可以完全提取信息的挖掘模式是当前的研究热点。提出一种并行动态位向量频繁闭合序列模式的挖掘算法(PDBV FCSP),该算法采用多核处理器架构和DBV数据结构相结合的方式,有效加快了序列数据库的处理速度,并对搜索空间进行划分,尽早执行预处理序列的闭合检查,减少了所需的存储空间和挖掘频繁闭合序列模式的执行时间,克服了现有并行挖掘算法通信开销、同步和数据复制等问题。利用重新分配工作的动态负载平衡机制,解决处理器之间的负载均衡问题,最大限度地减少了CPU空闲时间。对DBV VDF算法和PDBV FCSP(2 4核)算法进行仿真比较,结果表明,PDBV FCSP算法在运行时间、内存使用和可伸缩性等方面都有较优的性能提升,且当内核数增加时,性能更优。  相似文献   

17.
The parallelization of heuristic methods allows the researchers both to explore the solution space more extensively and to accelerate the search process. Nowadays, there is an increasing interest on developing parallel algorithms using standard software components that take advantage of modern microprocessors including several processing cores with local and shared cache memories. The aim of this paper is to show it is possible to parallelize algorithms included in computational software using standard software libraries in low-cost multi-core systems, instead of using expensive high-performance systems or supercomputers. In particular, it is analyzed the benefits provided by master-worker and island parallel models, implemented with MPI and OpenMP software libraries, to parallelize population-based meta-heuristics. The capacitated vehicle routing problem with hard time windows (VRPTW) has been used to evaluate the performance of these parallel strategies. The empirical results for a set of Solomon's benchmarks show that the parallel approaches executed on a multi-core processor produce better solutions than the sequential algorithm with respect to both the quality of the solutions obtained and the runtime required to get them. Both MPI and OpenMP parallel implementations are able to obtain better or at least equal solutions (in terms of distance traveled) than the best known ones for the considered benchmark instances.  相似文献   

18.
为提升城市城市道路拥堵检测和治理效率,提出一种基于势场修正多处理器并行聚类的城市道路拥堵时空分析方法。首先,利用GIS四维空间时态数据给出城市道路拥堵的时空模型,并通过设置虚拟数据参数实现时间的低密度采样处理,获得城市道路拥堵路段时空规律性的有效检测;其次,基于势场修正法构建多处理器并行聚类方法,分别设计了距离矩阵、邻域半径和密度函数的并行化多处理计算方法,并实现了并行聚类算法设计,同时给出上述并行计算过程的计算复杂度分析定理;最后,以北京市为试验区,对所提城市道路拥堵分析算法性能进行了验证,实验结果表明,所提方法可实现城市城市道路拥堵情况的快速有效检效检测分析,可为城市道路拥堵管理提供数据支撑。  相似文献   

19.
Dynamic load balancing for parallel polygon rendering   总被引:2,自引:0,他引:2  
Using parallel processing for visualization speeds up computer graphics rendering of complex data sets. A parallel algorithm designed for polygon scan conversion and rendering is presented which supports fast rendering of highly complex data sets using advanced lighting models. Dedicated graphics rendering engines do not necessarily suit such data sets, although they can support real-time update of moderately complex scenes using simple lighting. Advantages to using a software-based approach include the feasibility of adding special rendering features to the program and the capability of integrating a parallel scientific application with a parallel graphics renderer. A new work decomposition strategy presented, called task adaptive, is based on dynamically partitioning the amount of computational work left at a given time. The algorithm uses a heuristic for dynamic task decomposition in which image space tasks are partitioned without requiring interruption of the partitioned processor. A sophisticated memory referencing strategy lets local memory access graphics data during rendering. This permits implementation of the algorithm on a distributed memory multiprocessor. An in-depth analysis of the overhead costs accompanying parallel processing shows where performance is adequate or could be improved  相似文献   

20.
The architectural landscape of high-performance computing stretches from superscalar uniprocessor to explicitly parallel systems, to dedicated hardware implementations of algorithms. Single-purpose hardware can achieve the highest performance and uniprocessors can be the most programmable. Between these extremes, programmable and reconfigurable architectures provide a wide range of choice in flexibility, programmability, computational density, and performance. The UCSC Kestrel parallel processor strives to attain single-purpose performance while maintaining user programmability. Kestrel is a single-instruction stream, multiple-data stream (SIMD) parallel processor with a 512-element linear array of 8-bit processing elements. The system design focuses on efficient high-throughput DNA and protein sequence analysis, but its programmability enables high performance on computational chemistry, image processing, machine learning, and other applications. The Kestrel system has had unexpected longevity in its utility due to a careful design and analysis process. Experience with the system leads to the conclusion that programmable SIMD architectures can excel in both programmability and performance. This work presents the architecture, implementation, applications, and observations of the Kestrel project at the University of California at Santa Cruz.  相似文献   

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