Big Data has shown lots of potential in numerous domain and becomes one of the emerging technologies that are bringing revolution in some real world industry. It has the power to provide insights into the unseen aspec...
详细信息
ISBN:
(纸本)9781509060580
Big Data has shown lots of potential in numerous domain and becomes one of the emerging technologies that are bringing revolution in some real world industry. It has the power to provide insights into the unseen aspects of immense volume of data. Some applications are processing the data using a store-then-process paradigm, whereas other applications, like telecommunications and large-scale sensor networks, have to analyze continuous data flow online. Stream processing Engines(SPEs) are designed to support applications which require timely analysis of high volume data streams. The dynamic nature of data stream requires SPEs to have high scalability. However, current SPEs mostly adopt a static configuration and can not scale out/in flexibly along with the changing of the data stream. In this paper, we proposed a fuzzy logic based runtime bottleneck operator detection approach to improve the scalability of SPEs by providing resources in the cloud environment. Our experimental results show that the fuzzy logic component developed in this work could detect bottleneck operators efficiently. Compared with other bottleneck detection methods, the decision results generated by our approach is more flexible and will not scale out/in the system when the workload change instantly.
Semijoin has traditionally been relied upon for reducing the communication cost required for distributed query processing. However, judiciously applying join operations as reducers can lead to further reduction in the...
详细信息
ISBN:
(纸本)0818620528
Semijoin has traditionally been relied upon for reducing the communication cost required for distributed query processing. However, judiciously applying join operations as reducers can lead to further reduction in the communication cost. In view of this fact, we explore in this paper the approach of using join operations, in addition to semijoins, as reducers in distributed query processing. We first show that the problem of determining a sequence of join operations for a query graph can be transformed to that of finding a set of cuts to that graph, where a cut to a graph is a partition of the nodes in that graph. In light of the mapping we develop an efficient heuristic algorithm to determine an effective sequence of join reducers for a query. The algorithm using the concept of divide-and-conquer is shown to have polynomial time complexity. Examples are also given to illustrate our results.
In this work, we present a parallel implementation of Hestenes-Jacobi-One-sided method exploiting the CUDA environment of Graphics processing Units (GPUs). Our approach is based on a scheme which performs multiple ort...
详细信息
ISBN:
(纸本)9781538649756
In this work, we present a parallel implementation of Hestenes-Jacobi-One-sided method exploiting the CUDA environment of Graphics processing Units (GPUs). Our approach is based on a scheme which performs multiple orthogonalization processes in parallel, across multiple rows and columns. Driven by an outer loop, executed on the CPU, the algorithm configures the CUDA grid with threads and blocks in order to allow the CUDA-kernels to use the shared memory and avoid multiple accesses to global memory. We use this GPU-parallel algorithm in order to accelerate the Singular Value Decomposition (SVD) process which has a variety of applications in scientific computing, signal processing, automatic control and many other areas. Preliminar experiments show a significant improvements in terms of performances with respect to the CPU version and our previuos GPU version.
Given N matrices A1, A2,..., AN of size NxN, the matrix chain product problem is to compute A1 x A2 xx AN. Given an N x N matrix A, the matrix powers problem is to calculate the first N powers of A, i.e., A, A2, A3,.....
详细信息
The GCA (Global Cellular Automata) model is a very interesting and flexible model which can be used to implement all kind of parallel algorithms. The GCA model consists of a field of cells similar the Cellular Automat...
详细信息
ISBN:
(纸本)0769523129
The GCA (Global Cellular Automata) model is a very interesting and flexible model which can be used to implement all kind of parallel algorithms. The GCA model consists of a field of cells similar the Cellular Automata model. Each cell has links to a set of remote cells which can be dynamically changed from generation to generation. A cell reads the remote neighbors' states and then changes its own state according to a local rule. The model is massively parallel because all cells can change their states independently and in parallel. We have investigated how the GCA model can be implemented efficiently in hardware using a Field Programmable Gate Array (FPGA) prototyping platform. We have implemented a fully parallel architecture where all cells operate fully in parallel and other architectures where the cells are stored in memories in order to handle a large number of cells. We are showing that in the fully parallel architecture a speed-up of around 190 is realistic on a modern FPGA platform compared to a software implementation on a PC. In the partially parallel architecture based on memories the speed-up will be lower but the number of cells is only restricted by the capacity of the memories.
Several distributedapplications, implemented over today's Internet, are based on the assumption that participating agents collaborate in order to achieve their own goal. However, when these applications are model...
详细信息
ISBN:
(纸本)9781424416875
Several distributedapplications, implemented over today's Internet, are based on the assumption that participating agents collaborate in order to achieve their own goal. However, when these applications are modelled as unstructured distributed systems, the greater autonomy and decentralization encourage antisocial behaviours, which are likely to cause performance degradation for the whole system. This paper presents a fully distributed reputation management system that allows the evaluation of agent reputation in unstructured environments without any centralized coordination. The proposed approach is based on game theory and is capable of capturing the highly dynamic nature of the involved communities. As a representative example of an unstructured environment, Peer-to-peer (P2P) networks are considered. Those dynamic communities are affected by several antisocial behaviours, such as free riding. Since this phenomenon typically causes and exacerbates an unbalanced and unfair use of system resources, it has been considered as the case study in our work. The proposed solution exploits peer reputations in order to define an incentive system, whose main goal is the dissuasion from free riding.
In mission-critical activities, each user is allowed to access some specific, but not all, data gathered by wireless sensor networks. Yu et al [1] recently proposed a centralized fine grained data access control mecha...
详细信息
In this paper a fast algorithm for solving a large system with an essentially Toeplitz five-band coefficient matrix is presented. The first two and last two rows are influenced by boundary conditions. The five band co...
详细信息
ISBN:
(纸本)0769521320
In this paper a fast algorithm for solving a large system with an essentially Toeplitz five-band coefficient matrix is presented. The first two and last two rows are influenced by boundary conditions. The five band core of this matrix is factored as the product of tridiagonal matri-ces for the purpose of obtaining a solution of a linear system more efficiently. An error term for the approximate solution is presented following the work by Yan and Chung [12]. An algorithm is developed for solving the two systems and is tested using two multiprocessor machines with different architectures.
To cope with the growing requirements of data intensive scientific experiments, models and simulations the Large Scale Data Facility (LSDF) at KIT aims to support many scientific disciplines. The LSDF is a distributed...
详细信息
ISBN:
(纸本)9780769543284
To cope with the growing requirements of data intensive scientific experiments, models and simulations the Large Scale Data Facility (LSDF) at KIT aims to support many scientific disciplines. The LSDF is a distributed storage facility at Exabyte scale providing storage, archives, data bases and meta data repositories. Open interfaces and APIs support a variety of access methods to the highly available services for high throughput data applications. Tools for an easy and transparent access allow scientists to use the LSDF without bothering with the internal structures and technologies. In close cooperation with the scientific communities the LSDF provides assistance to efficiently organize data and meta data structures, and develops and deploys community specific software on the directly connected computing infrastructure.
in this paper, we extend the Reactive Approach to distributed computing. Reactive Systems allow one to use instantaneous broadcast events, which is a very powerful communication means between parallel components, in a...
详细信息
ISBN:
(纸本)081869209X
in this paper, we extend the Reactive Approach to distributed computing. Reactive Systems allow one to use instantaneous broadcast events, which is a very powerful communication means between parallel components, in addition to implicit synchronization. Extension to distribution implies that instantaneous broadcast becomes available over the network between local reactive areas. We describe a model of distributed reactive systems, called Synchronized Systems, and several algorithms of detection of instant termination to implement distributed instantaneous broadcast, in the infrastructure we choose to implement systems consist of distributed reactive machines connected to synchronizers. We present various implementations in Java, using SugarCubes, the RMI mechanism and another distributedprocessing Environment.
暂无评论