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Matching search in fractal video compression and its parallel implementation in distributed computing environments

APPLIED MATHEMATICAL MODELLING 2006年第8期30卷 677-687页

作者： Wang, Meiqing Huang, Zhehuang Lai, Choi-Hong Fuzhou Univ Coll Math & Comp Sci Fujian 350002 Peoples R China Univ Greenwich Old Royal Naval Coll Sch Comp & Math Sci London SE10 9LS England

Fractal video compression is a relatively new video compression method. Its attraction is due to the high compression ratio and the simple decompression algorithm. But its computational complexity is high and as a result parallel algorithms on high performance machines become one way out. In this study we partition the matching search, which occupies the majority of the work in a fractal video compression process, into small tasks and implement them in two distributed computing environments, one using DCOM and the other using NET Remoting technology, based on a local area network consists of loosely coupled PCs. Experimental results show that the parallel algorithm is able to achieve a high speedup in these distributed environments. (c) 2005 Elsevier Inc. All rights reserved.

关键词： fractal video compression distributed computing parallel algorithm local area network DCOM .NET remoting

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Parallel and distributed computing models on a graphics processing unit to accelerate simulation of membrane systems

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SIMULATION MODELLING PRACTICE AND THEORY 2014年 47卷 60-78页

作者： Maroosi, Ali Muniyandi, Ravie Chandren Sundararajan, Elankovan Zin, Abdullah Mohd Natl Univ Malaysia Fac Technol & Informat Sci Res Ctr Software Technol & Management Bangi 43600 Selangor Malaysia

Membrane systems are parallel distributed computing models that are used in a wide variety of areas. Use of a sequential machine to simulate membrane systems loses the advantage of parallelism in Membrane computing. In this paper, an innovative classification algorithm based on a weighted network is introduced. Two new algorithms have been proposed for simulating membrane systems models on a Graphics Processing Unit (GPU). Communication and synchronization between threads and thread blocks in a CPU are time-consuming processes. In previous studies, dependent objects were assigned to different threads. This increases the need for communication between threads, and as a result, performance decreases. In previous studies, dependent membranes have also been assigned to different thread blocks, requiring inter-block communications and decreasing performance. The speedup of the proposed algorithm on a CPU that classifies dependent objects using a sequential approach, for example with 512 objects per membrane, was 82x, while for the previous approach (Algorithm 1), it was 8.2x. For a membrane system with high dependency among membranes, the speedup of the second proposed algorithm (Algorithm 3) was 12 x, while for the previous approach (Algorithm 1) and the first proposed algorithm (Algorithm 2) that assign each membrane to one thread block, it was 1.8x. (C) 2014 Elsevier B.V. All rights reserved.

关键词： Membrane computing Graphics processing unit Membrane systems distributed computing Parallel processing Weighted network

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Motivating Smartphone Collaboration in Data Acquisition and distributed computing

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IEEE TRANSACTIONS ON MOBILE computing 2014年第10期13卷 2320-2333页

作者： Duan, Lingjie Kubo, Takeshi Sugiyama, Kohei Huang, Jianwei Hasegawa, Teruyuki Walrand, Jean Singapore Univ Technol & Design Singapore 138682 Singapore KDDI R&D Labs Inc Yokosuka Kanagawa Japan Chinese Univ Hong Kong Dept Informat Engn Hong Kong Hong Kong Peoples R China Univ Calif Berkeley Dept Elect Engn & Comp Sci Berkeley CA 94720 USA

This paper analyzes and compares different incentive mechanisms for a master to motivate the collaboration of smartphone users on both data acquisition and distributed computing applications. To collect massive sensitive data from users, we propose a reward-based collaboration mechanism, where the master announces a total reward to be shared among collaborators, and the collaboration is successful if there are enough users wanting to collaborate. We show that if the master knows the users' collaboration costs, then he can choose to involve only users with the lowest costs. However, without knowing users' private information, then he needs to offer a larger total reward to attract enough collaborators. Users will benefit from knowing their costs before the data acquisition. Perhaps surprisingly, the master may benefit as the variance of users' cost distribution increases. To utilize smartphones' computation resources to solve complex computing problems, we study how the master can design an optimal contract by specifying different task-reward combinations for different user types. Under complete information, we show that the master involves a user type as long as the master's preference characteristic outweighs that type's unit cost. All collaborators achieve a zero payoff in this case. If the master does not know users' private cost information, however, he will conservatively target at a smaller group of users with small costs, and has to give most benefits to the collaborators.

关键词： Smartphone application data acquisition distributed computing game theory contract theory

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Playdoh: A lightweight Python library for distributed computing and optimisation

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JOURNAL OF COMPUTATIONAL SCIENCE 2013年第5期4卷 352-359页

作者： Rossant, Cyrille Fontaine, Bertrand Goodman, Dan F. M. CNRS Lab Psychol Percept Paris France Univ Paris 05 Paris France Ecole Normale Super Dept Etudes Cognit F-75005 Paris France

Parallel computing is now an essential paradigm for high performance scientific computing. Most existing hardware and software solutions are expensive or difficult to use. We developed Playdoh, a Python library for distributing computations across the free computing units available in a small network of multicore computers. Playdoh supports independent and loosely coupled parallel problems such as global optimisations, Monte Carlo simulations and numerical integration of partial differential equations. It is designed to be lightweight and easy to use and should be of interest to scientists wanting to turn their lab computers into a small cluster at no cost. (C) 2011 Elsevier B.V. All rights reserved.

关键词： Python Parallel computing distributed computing Optimisation High performance computing

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Precise Mass-Market Energy Demand Management Through Stochastic distributed computing

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IEEE TRANSACTIONS ON SMART GRID 2013年第4期4卷 2017-2027页

作者： Papalexopoulos, Alex Beal, Jacob Florek, Steven ECCO Int San Francisco CA 94104 USA BBN Technol Cambridge MA 02138 USA ColorPower Berkeley CA USA

Even though demand response (DR) participation has substantial benefits to the market as a whole, current DR programs suffer from a collection of market, regulatory, infrastructure and technology problems, such as lack of scalability, lack of privacy, imprecision, and nonacceptance by customers. This paper describes how a fundamentally different DR approach, based on service priority tiers for appliances and on stochastic distributed computing, can overcome these problems and be integrated with energy markets. Our approach takes advantage of inexpensive communications technology to estimate the state of home and small-business major electrical appliances and have those appliances respond to power grid state signals within a few seconds. Organizing appliances into service priority tiers allows retail customer power demand to be de-commoditized, making these DR resources a potent force for improving the efficiency of energy markets. This paper describes the proposed methodology, examines how it can be integrated into energy markets, and presents results from mathematical analysis and from simulation of 100 000 devices.

关键词： Demand response distributed computing locational marginal pricing power market auctions stochastic control

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A Fundamental Storage-Communication Tradeoff for distributed computing With Straggling Nodes

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IEEE TRANSACTIONS ON COMMUNICATIONS 2020年第12期68卷 7311-7327页

作者： Yan, Qifa Wigger, Michele Yang, Sheng Tang, Xiaohu IP Paris Telecom Paris LTCI F-91120 Palaiseau France Univ Paris Saclay Univ Paris Sud Cent Supelec L2SCNRS F-91192 Gif Sur Yvette France Southwest Jiaotong Univ Informat Secur & Natl Comp Grid Lab Chengdu 611756 Peoples R China

Placement delivery arrays for distributed computing (Comp-PDAs) have recently been proposed as a framework to construct universal computing schemes for MapReduce-like systems. In this work, we extend this concept to systems with straggling nodes, i.e., to systems where a subset of the nodes cannot accomplish the assigned map computations in due time. Unlike most previous works that focused on computing linear functions, our results are universal and apply for arbitrary map and reduce functions. Our contributions are as follows. Firstly, we show how to construct a universal coded computing scheme for MapReduce-like systems with straggling nodes from any given Comp-PDA. We also characterize the storage and communication loads of the resulting scheme in terms of the Comp-PDA parameters. Then, we prove an information-theoretic converse bound on the storage-communication (SC) tradeoff achieved by universal computing schemes with straggling nodes. We show that the information-theoretic bound matches the performance achieved by the coded computing schemes with straggling nodes corresponding to the Maddah-Ali and Niesen (MAN) PDAs, i.e., to the Comp-PDAs describing Maddah-Ali and Niesen's coded caching scheme. Interestingly, the MAN-PDAs are optimal for any number of straggling nodes. This implies that the map phase of optimal coded computing schemes does not need to be adapted to the number of stragglers in the system. We show that the points that lie exactly on the fundamental SC tradeoff cannot be achieved with Comp-PDAs that require smaller number of files than the MAN-PDAs. This is however possible for some of the points that lie close to the SC tradeoff. For these latter points, the decrease in the requested number of files can be exponential in the number of nodes of the system. We also model the total execution time, and numerically show that the active set size should be chosen to balance the duration of the map phase and the durations of the shuffle and reduce pha

关键词： Computational modeling Numerical models Servers Electronic mail Personal digital assistants Complexity theory distributed computing storage communication straggler MapReduce placement delivery array

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Proactive scheduling in distributed computing-A reinforcement learning approach

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JOURNAL OF PARALLEL AND distributed computing 2014年第7期74卷 2662-2672页

作者： Tong, Zhao Xiao, Zheng Li, Kenli Li, Keqin Hunan Univ Coll Informat Sci & Engn Changsha 410082 Hunan Peoples R China SUNY Coll New Paltz Dept Comp Sci New Paltz NY 12561 USA

In distributed computing such as grid computing, online users submit their tasks anytime and anywhere to dynamic resources. Task arrival and execution processes are stochastic. How to adapt to the consequent uncertainties, as well as scheduling overhead and response time, are the main concern in dynamic scheduling. Based on the decision theory, scheduling is formulated as a Markov decision process (MDP). To address this problem, an approach from machine learning is used to learn task arrival and execution patterns online. The proposed algorithm can automatically acquire such knowledge without any aforehand modeling, and proactively allocate tasks on account of the forthcoming tasks and their execution dynamics. Under comparison with four classic algorithms such as Min-Min, Min-Max, Suffrage, and ECT, the proposed algorithm has much less scheduling overhead. The experiments over both synthetic and practical environments reveal that the proposed algorithm outperforms other algorithms in terms of the average response time. The smaller variance of average response time further validates the robustness of our algorithm. (C) 2014 Elsevier Inc. All rights reserved.

关键词： distributed computing Markov decision process Queueing model Reinforcement learning Task scheduling

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Service-centric globally distributed computing

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IEEE INTERNET computing 2003年第4期7卷 36-43页

作者： Graupner, S Kotov, V Andrzejak, A Trinks, H Hewlett Packard Labs Palo Alto CA 94304 USA Carnegie Mellon Univ Moffett Field CA USA Konrad Zuse Inst Berlin Germany Santa Clara Univ Santa Clara CA 95053 USA

An automated service demand-supply control system can improve a large-scale grid infrastructure comprising a federation of distributed utility data centers.

关键词： distributed computing Image storage Automatic control Control systems Application software Fabrics Large-scale systems Resource virtualization LAN interconnection Network servers

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The EM algorithm in a distributed computing environment for modelling environmental space-time data

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ENVIRONMENTAL MODELLING & SOFTWARE 2009年第9期24卷 1027-1035页

作者： Fasso, Alessandro Cameletti, Michela Univ Bergamo Dept Informat Technol & Math Methods I-24044 Bergamo BG Italy

Statistical models for spatio-temporal data are increasingly used in environmetrics, climate change, epidemiology, remote sensing and dynamical risk mapping. Due to the complexity of the relationships among the involved variables and dimensionality of the parameter set to be estimated, techniques for model definition and estimation which can be worked out stepwise are welcome. In this context, hierarchical models are a suitable solution since they make it possible to define the joint dynamics and the full likelihood starting from simpler conditional submodels. Moreover, for a large class of hierarchical models, the maximum likelihood estimation procedure can be simplified using the Expectation-Maximization (EM) algorithm. In this paper, we define the EM algorithm for a rather general three-stage spatio-temporal hierarchical model, which includes also spatio-temporal covariates. In particular, we show that most of the parameters are updated using closed forms and this guarantees stability of the algorithm unlike the classical optimization techniques of the Newton-Raphson type for maximizing the full likelihood function. Moreover, we illustrate how the EM algorithm can be combined with a spatio-temporal parametric bootstrap for evaluating the parameter accuracy through standard errors and non-Gaussian confidence intervals. To do this a new software library in form of a standard R package has been developed. Moreover, realistic simulations on a distributed computing environment allow us to discuss the algorithm properties and performance also in terms of convergence iterations and computing times. (C) 2009 Elsevier Ltd. All rights reserved.

关键词： Separability Spatial covariance Kalman filter Environmental statistics distributed computing

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Experimental verification of a distributed computing strategy for structural health monitoring

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SMART STRUCTURES AND SYSTEMS 2007年第4期3卷 455-474页

作者： Gao, Y. Spencer, B. F., Jr. Univ Illinois Dept Civil & Environm Engn Urbana IL 61801 USA WSP Cantor Seinuk New York NY 10017 USA

A flexibility-based distributed computing strategy (DCS) for structural health monitoring (SHM) has recently been proposed which is suitable for implementation on a network of densely distributed smart sensors. This approach uses a hierarchical strategy in which adjacent smart sensors are grouped together to form sensor communities. A flexibility-based damage detection method is employed to evaluate the condition of the local elements within the communities by utilizing only locally measured information. The damage detection results in these communities are then communicated with the surrounding communities and sent back to a central station. Structural health monitoring can be done without relying on central data acquisition and processing. The main purpose of this paper is to experimentally verify this flexibility-based DCS approach using wired sensors;such verification is essential prior to implementation on a smart sensor platform. The damage locating vector method that forms foundation of the DCS approach is briefly reviewed, followed by an overview of the DCS approach. This flexibility-based approach is then experimentally verified employing a 5.6 m long three-dimensional truss structure. To simulate damage in the structure, the original truss members are replaced by ones with a reduced cross section. Both single and multiple damage scenarios are studied. Experimental results show that the DCS approach can successfully detect the damage at local elements using only locally measured information.

关键词： health monitoring distributed computing smart sensor flexibility matrix truss

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