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parallel computation of page rank using two-stage methods

Civil-Comp Proceedings 2017年 111卷

作者： Migallon, H. Migallon, V. Penades, J. Department of Physics and Computer Architectures University Miguel Hernández Alicante Spain Department of Computer Science and Artificial Intelligence University of Alicante Alicante Spain

In this work we present parallel algorithms based on the use of two-stage methods for solving the PageRank problem as a linear system. Different parallel versions of these methods are explored and their convergence properties are analyzed. The parallel implementation has been developed using a mixed MPI/OpenMP model to exploit parallelism beyond a single level. In order to investigate and analyze the proposed parallel algorithms, we have used several realistic large datasets. The numerical results show that the proposed algorithms can significantly speed up the convergence time with respect to the parallel Power algorithm and behave better than other well-known techniques. © Civil-Comp Press, 2017.

关键词： parallel algorithms Linear systems Memory architecture Convergence properties Distributed Memory Investigate and analyze PageRank parallel Computation parallel implementations Shared memory Two stage methods

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A comparative study of parallel software SURF implementations

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CONCURRENCY AND COMPUTATION-PRACTICE & EXPERIENCE 2014年第17期26卷 2758-2771页

作者： Hidalgo-Paniagua, Alejandro Vega-Rodriguez, Miguel A. Pavon, Nieves Ferruz, Joaquin Univ Extremadura Dept Technol Comp & Commun Polytech Sch Caceres Spain Univ Huelva Higher Tech Sch Engn Dept Informat Technol Huelva Spain Univ Seville Higher Tech Sch Engn Dept Syst Engn & Automat Seville Spain

Nowadays, it is common to find problems that require recognizing objects in an image, tracking them along time, or recognizing a complete real-world scene. One of the most known and used algorithms to solve these problems is the Speeded Up Robust Features (SURF) algorithm. SURF is a fast and robust local, scale and rotation invariant, features detector. This means that it can be used for detecting and describing a set of points of interest (keypoints) from an image. Because of the importance of this algorithm and the rise of the parallelism-based technologies, in the last years, diverse parallel implementations of SURF have been proposed. These parallel implementations are based on very different techniques: Compute Unified Device Architecture, OpenMp, OpenCL, and so on. In conclusion, we think valuable a comparative study of all of them highlighting the advantages and disadvantages of each parallel implementation. To our best knowledge, this article is the first attempt to do this comparative study. In order to make this study, we have used the standard metrics and image collection in this field, as well as other important metrics in parallelism as speedup and efficiency. Copyright (c) 2013 John Wiley & Sons, Ltd.

关键词： parallel implementations SURF comparative study CUDA OpenCL OpenMP OpenCV

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GPU-accelerated Monte Carlo Localization for underwater robots

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IFAC-PapersOnLine 2015年第2期28卷 76-81页

作者： Da Silva Vale, Rodrigo Teiles De Barros, Ettore Apolonio De Castro Martins, Thiago Mechatronic Engineering Department Polytechnic School University of São Paulo São Paulo Brazil

This paper proposes a navigation system for Remotely Operated Vehicle (ROV) operating around man-made structures such as a tube of a hydroelectric power plant. This kind of environment usually presents a combination of low visibility and ferromagnetic anomalies, so one of the aims of this paper is to propose a navigation method not dependent on cameras neither on magnetometers. In these types of environment, it is customary to have a map of its dimensions known a priori, and with this, it is possible to use an algorithm that is called Monte Carlo Localization. The drawback of using this algorithm is its high computational cost, but as it allows a parallel implementation, this disadvantage can be overcome. Thus, in this work is proposed a parallel implementation using a graphic processing unit (GPU) through CUDA architecture. The navigation system proposed in this work was validated by comparing experimental results with a highly accurate optical reference system. The tests were conducted in a rectangular tank of a known size, and the results show high robustness and real-time capabilities of the proposed navigation system. © 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

关键词： Graphics processing unit Hydroelectric power Hydroelectric power plants Monte Carlo methods Navigation Navigation systems Remotely operated vehicles Robots Underwater acoustics Computational costs Graphic processing unit(GPU) Man made structures Monte Carlo localization Multibeam sonar parallel implementations Real time capability Remotely Operated Vehicles (ROV)

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parallel IMPLEMENTATION OF THE BOX COUNTING ALGORITHM IN OPENCL

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FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY 2015年第3期23卷 1550023-1550023页

作者： Mukundan, Ramakrishnan Univ Canterbury Dept Comp Sci & Software Engn Christchurch 1 New Zealand

The box counting algorithm is a well-known method for the computation of the fractal dimension of an image. It is often implemented using a recursive subdivision of the image into a set of regular tiles or boxes. parallel implementations often try to map the boxes to different compute units, and combine the results to get the total number of boxes intersecting a shape. This paper presents a novel and highly efficient method using Open Computing Language (OpenCL) kernels to perform the computation on a per-pixel basis. The mapping and reduction stages are performed in a single pass, and therefore require the enqueuing of only a single kernel. Each instance of the kernel updates the information pertaining to all the boxes containing the pixel, and simultaneously increments the box counters at multiple levels, thereby eliminating the need for another pass to perform the summation. The complete implementation and coding details of the proposed method are outlined. The performance of the method on different processors are analyzed with respect to varying image sizes.

关键词： Fractal Dimension OpenCL Kernels Box Counting Algorithm Multifractal Analysis parallel implementations

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An Imperialistic Strategy Approach to Continuous Global Optimization Problem 16

An Imperialistic Strategy Approach to Continuous Global Opti...

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16th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing (SYNASC)

作者： Anescu, George Univ Politehn Bucuresti Power Plant Engn Fac Bucharest 060042 Romania

ISBN: (纸本)9781479984480

The paper is introducing the principles of a new global optimization strategy, Imperialistic Strategy (IS), applied to the Continuous Global Optimization Problem (CGOP). Inspired from existing multi-population strategies, like the Island Model (IM) approaches to parallel Evolutionary Algorithms (EA) and the Imperialistic Competitive Algorithm (ICA), the proposed IS method is considered an optimization strategy for the reason that it can integrate other well-known optimization methods, which in the context are regarded as sub-methods (although in other contexts they are prominent global optimization methods). Four optimization methods were implemented and tested in the roles of sub-methods: Genetic Algorithm (GA) (a floating-point representation variant), Differential Evolution (DE), Quantum Particle Swarm Optimization (QPSO) and Artificial Bee Colony (ABC). The optimization performances of the proposed optimization methods were compared on a test bed of 9 known multimodal optimization problems by applying an appropriate testing methodology. The obtained increased success rates of IS multi-population variants compared to the success rates of the optimization sub-methods run separately, combined with the increased computing efficiencies possible to be perceived for parallel and distributed implementations, demonstrated that IS is a promising approach to CGOP.

关键词： genetic algorithms parallel algorithms quantum computing ABC CGOP DE EA GA ICA IM IS multipopulation variants QPSO artificial bee colony continuous global optimization problem differential evolution distributed implementations floating-point representation variant genetic algorithm imperialistic competitive algorithm imperialistic strategy approach island model multimodal optimization problems multipopulation strategies parallel evolutionary algorithms parallel implementations quantum particle swarm optimization Biological cells Genetic algorithms Linear programming Optimization Sociology Statistics Vectors Artificial Bee Colony Continuous Global Optimization Problem Differential Evolution Genetic Algorithm IS Imperialistic Competitive Algorithm Imperialistic Strategy Island Model Quantum Particle Swarm Optimization Genetic Algorithm (GA) MT activity based costing Independent component analysis islet cell antibody Instant messaging Particle swarm optimization Gallium cytology Sociology parallel algorithms quantum computing Policies and plans bee colonies linear programming

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Suffix array and Lyndon factorization of a text

Suffix array and Lyndon factorization of a text

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Journal of Discrete Algorithms

作者： Mantaci, Sabrina Restivo, Antonio Rosone, Giovanna Sciortino, Marinella University of Palermo Dipartimento di Matematica e Informatica Via Archirafi 34 90123 Palermo Italy

The main goal of this paper is to highlight the relationship between the suffix array of a text and its Lyndon factorization. It is proved in [15] that one can obtain the Lyndon factorization of a text from its suffix array. Conversely, here we show a new method for constructing the suffix array of a text that takes advantage of its Lyndon factorization. The surprising consequence of our results is that, in order to construct the suffix array, the local suffixes inside each Lyndon factor can be separately processed, allowing different implementative scenarios, such as online, external and internal memory, or parallel implementations. Based on our results, the algorithm that we propose sorts the suffixes by starting from the leftmost Lyndon factors, even if the whole text or the complete Lyndon factorization are not yet available. © 2014 Elsevier B.V. All rights reserved.

关键词： Factorization Combinatorial mathematics Computational methods Internal memory Lyndon words parallel implementations Suffix arrays

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Algorithm 928: A General, parallel Implementation of Dantzig-Wolfe Decomposition

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ACM TRANSACTIONS ON MATHEMATICAL SOFTWARE 2013年第3期39卷 1-10页

作者： Rios, Joseph NASA Moffett Field CA 94035 USA

Dantzig-Wolfe Decomposition is recognized as a powerful, algorithmic tool for solving linear programs of block-angular form. While use of the approach has been reported in a wide variety of domains, there has not been a general implementation of Dantzig-Wolfe decomposition available. This article describes an open-source implementation of the algorithm. It is general in the sense that any properly decomposed linear program can be provided to the software for solving. While the original description of the algorithm was motivated by its reduced memory usage, modern computers can also take advantage of the algorithm's inherent parallelism. This implementation is parallel and built upon the POSIX threads (pthreads) library. Some computational results are provided to motivate use of such parallel solvers, as this implementation outperforms state-of-the-art commercial solvers in terms of wall-clock runtime by an order of magnitude or more on several problem instances.

关键词： Algorithms Linear programming optimization parallel implementations

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A survey on parallel ant colony optimization

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APPLIED SOFT COMPUTING 2011年第8期11卷 5181-5197页

作者： Pedemonte, Martin Nesmachnow, Sergio Cancela, Hector [a]Facultad de Ingeniería Universidad de la República Uruguay

Ant colony optimization (ACO) is a well-known swarm intelligence method, inspired in the social behavior of ant colonies for solving optimization problems. When facing large and complex problem instances, parallel computing techniques are usually applied to improve the efficiency, allowing ACO algorithms to achieve high quality results in reasonable execution times, even when tackling hard-to-solve optimization problems. This work introduces a new taxonomy for classifying software-based parallel ACO algorithms and also presents a systematic and comprehensive survey of the current state-of-the-art on parallel ACO implementations. Each parallel model reviewed is categorized in the new taxonomy proposed, and an insight on trends and perspectives in the field of parallel ACO implementations is provided. (C) 2011 Elsevier B. V. All rights reserved.

关键词： Ant colony optimization parallel implementations Taxonomy

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parallel CBIR implementations with load balancing algorithms

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JOURNAL OF parallel AND DISTRIBUTED COMPUTING 2006年第8期66卷 1062-1075页

作者： Bosque, Jose L. Robles, Oscar D. Pastor, Luis Rodriguez, Angel U Rey Juan Carlos Dpto Informat Estadist & Telemat Madrid 28933 Spain UPM Dept Tecnol Foton Boadilla Del Monte 28660 Spain

The purpose of content-based information retrieval (CBIR) systems is to retrieve, from real data stored in a database, information that is relevant to a query. When large volumes of data are considered, as it is very often the case with databases dealing with multimedia data, it may become necessary to look for parallel solutions in order to store and gain access to the available items in an efficient way. Among the range of parallel options available nowadays, clusters stand out as flexible and cost effective solutions, although the fact that they are composed of a number of independent machines makes it easy for them to become heterogeneous. This paper describes a heterogeneous cluster-oriented CBIR implementation. First, the cluster solution is analyzed without load balancing, and then, a new load balancing algorithm for this version of the CBIR system is presented. The load balancing algorithm described here is dynamic, distributed, global and highly scalable. Nodes are monitored through a load index which allows the estimation of their total amount of workload, as well as the global system state. Load balancing operations between pairs of nodes take place whenever a node finishes its job, resulting in a receptor-triggered scheme which minimizes the system's communication overhead. Globally, the CBIR cluster implementation together with the load balancing algorithm can cope effectively with varying degrees of heterogeneity within the cluster;the experiments presented within the paper show the validity of the overall strategy. Together, the CBIR implementation and the load balancing algorithm described in this paper span a new path for performant, cost effective CBIR systems which has not been explored before in the technical literature. (C) 2006 Elsevier Inc. All rights reserved.

关键词： parallel implementations CBIR systems load balancing algorithms

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Fast and flexible elliptic curve point arithmetic over prime fields

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IEEE TRANSACTIONS ON COMPUTERS 2008年第3期57卷 289-302页

作者： Longa, Patrick Miri, Ali Univ Ottawa Sch Informat Technol & Engn Ottawa ON K1N 6N5 Canada

We present an innovative methodology for accelerating the elliptic curve point formulas over prime fields. This flexible technique uses the substitution of multiplication with squaring and other cheaper operations by exploiting the fact that field squaring is generally less costly than multiplication. Applying this substitution to the traditional formulas, we obtain faster point operations in unprotected sequential implementations. We also show the significant impact our methodology has in protecting against simple side-channel (SSCA) attacks. We modify the elliptic curve cryptography (ECC) point formulas to achieve a faster atomic structure when applying side-channel atomicity protection. In contrast to previous atomic operations that assume that squarings are indistinguishable from multiplications, our new atomic structure offers true SSCA-protection because it includes squaring in its formulation. Moreover, we extend our implementation to parallel architectures such as Single-Instruction Multiple-Data (SIMD). With the introduction of a new coordinate system and the flexibility of our methodology, we present, to our knowledge, the fastest formulas for SIMD-based schemes that are capable of executing three and four operations simultaneously. Finally, a new parallel SSCA-protected scheme is proposed for multiprocessor/parallel architectures by applying the atomic structure presented in this work. Our parallel and atomic operations are shown to be significantly faster than previous implementations.

关键词： elliptic curve point arithmetic side-channel attacks atomicity SIMD operation parallel implementations

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