Volunteer computing projects use donated CPU time to solve problems that would otherwise be too computationally intensive to solve. the donated CPU time comes from computers whose owners install a volunteer computing ...
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ISBN:
(纸本)9780889867741
Volunteer computing projects use donated CPU time to solve problems that would otherwise be too computationally intensive to solve. the donated CPU time comes from computers whose owners install a volunteer computing client program on their computer, allowing a project to use the computer's idle time. the low participation rate in volunteer computing and the increasing number of volunteer computing projects make improvements that more effectively use the donated CPU cycles very important. Past work showed that using certain task retrieval policies could increase the number of tasks volunteer computing clients complete. However, the past work assumed that the volunteered computers had a single CPU and the task retrieval methods that resulted in more completed tasks required the client to be connected to the Internet more often than the other policies. We simulated the task retrieval policies for computers with multi-core CPUs and found that in most cases, the multi-core architecture can lead to a slightly greater than linear increase in the number of tasks that the clients complete, relative to the number of cores the computer running the client has. Additionally, the multi-core architecture can reduce the performance gap between the best and worst performing policies significantly, affecting which policies are used.
We analyze the parallel processing in clusters of computers of a prediction method based on the improvement of Radial Basis Function (RBF) neural networks using matrix decomposition techniques such as the Singular Val...
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We analyze the parallel processing in clusters of computers of a prediction method based on the improvement of Radial Basis Function (RBF) neural networks using matrix decomposition techniques such as the Singular Value Decomposition (SVD) and the QR-cp factorization. parallel processing is required because of the extensive computation found in those techniques, but the reward is obtained in form of better prediction performance and less network complexity. this general prediction procedure (in the sequential version) was published in the technical literature previously, with a high degree of experimental success. parallelism is a convenient way to make this prediction module available for inexpensive operation within decision-making contexts. We discuss two alternatives of concurrency: parallel implementation of the prediction procedure over the ScaLAPACK suite, and the formulation of another parallel routine customized to a higher degree for better performance.
A cluster system can potentially provide features of high availability, extended scalability and fault tolerance. However, there are few cluster systemsthat have transactional capability withdistributed lock manager...
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A cluster system can potentially provide features of high availability, extended scalability and fault tolerance. However, there are few cluster systemsthat have transactional capability withdistributed lock managers to provide a single system image for transactional applications. We propose a distributed lock manager architecture called SSDLM for a cluster system, which is based on self-management of shared locks in a node to decrease lock management overhead in a cluster system. this paper describes the algorithm and the design of the lock management in SSDLM using data structures and processes. Finally, we test it through our experiments in terms of transaction response time and lock response time. the experimental results show that the overall performance improves with a small increase of nodes but becomes saturated soon, and that the locality of shared locks in SSDLM is effective for all experiments, and especially outstanding in the lock response time for read intensive transactions.
We present in this paper a novel method to predict application runtimes on backfilling parallelsystems. the method is based on mining historical data to obtain important parameters. these parameters are then applied ...
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ISBN:
(纸本)9780769539393
We present in this paper a novel method to predict application runtimes on backfilling parallelsystems. the method is based on mining historical data to obtain important parameters. these parameters are then applied to predict the runtime of future applications. It has been shown in previous works [4], [21] that both underestimate and inaccuracy in prediction have adverse impacts on scheduling performance of backfilling systems. In our study, we try to reduce the number of jobs that are underestimated and reduce the prediction error as much as possible. Comparing with other predictors, experimental results show that our predictor is upto 25% better with respect to the problem of underestimate. Moreover, using the metric proposed in [21] for the accuracy, our predictor improves upto 32%.
In order to control risks and facilitate effective decision-making, the relations among risk chains should be systematically analyzed, which is a very difficult process. the aim of this research is to understand the c...
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ISBN:
(纸本)9781509055043
In order to control risks and facilitate effective decision-making, the relations among risk chains should be systematically analyzed, which is a very difficult process. the aim of this research is to understand the connective generating structure of risk chains and plan problem solving accordingly. therefore, in order to select the analysis method, association rule mining was applied. From the extracted data, the height of the sources of a risk chain and recurrence nature of a risk could be discovered. It is expected that these results can prevent the occurrence of risk chains caused by human factors.
the goal of medical concept extraction is to identify phrases that refer to medical concepts of interest such as problems, treatments and tests from medical documents. In this study, three types of medical concept ext...
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ISBN:
(纸本)9781509055043
the goal of medical concept extraction is to identify phrases that refer to medical concepts of interest such as problems, treatments and tests from medical documents. In this study, three types of medical concept extraction models are developed and then compared them. the first concept extraction task is mainly based upon semantic features obtained from a domain-knowledge based method using MetaMap, and the other two are machine-learning methods with using sequential classifier Conditional Random Fields (CRF) for both with and without MetaMap outputs as features. Among the three concept extraction models, the combined approach of CRF with MetaMap features obtained the best results.
this paper presents the specification and implementation procedure using a microcomputer network based autonomous distributed control architecture for industrial multirobot systems. the procedure is based on the conce...
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this paper presents the specification and implementation procedure using a microcomputer network based autonomous distributed control architecture for industrial multirobot systems. the procedure is based on the concept of data flow network controlled by communicating sequential processes to perform coordinated tasks. Robots and other computerized industrial devices such as conveyors and manufacturing machines are defined as object-oriented Petri nets. A modular and hierarchical approach is adopted to define a set of Petri net type diagrams which represent concurrent activities of control processes for such devices. Asynchronous and synchronous interactions are modelled by places and transitions, respectively, in global process interaction nets. the control software is implemented on a computer network using Inmos transputers with true parallel processing and message passing primitives efficiently handled in hardware. Petri net based models are directly and efficiently transformed to corresponding codes in occam, the high level parallel. programming language defined for the transputer.
Similarity retrieval method of plasma emission videos using color and luminosity information has been proposed. this paper revises this method to introduce time series similarity. Plasma emission videos are clustered ...
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ISBN:
(纸本)9781509055043
Similarity retrieval method of plasma emission videos using color and luminosity information has been proposed. this paper revises this method to introduce time series similarity. Plasma emission videos are clustered by using several distances proposed and revised in order to categorize them. the soundness of the proposed methods is clarified through the experiment.
作者:
Xhafa, FatosDept. LSI
Univ. Politecnica de Catalunya Jordi Girona 1-3 08034 Barcelona Spain
In this paper we present an implementation of a generic memetic algorithm (MA) for the edge bi-connectivity augmentation problem (E2AUG). this problem is known for its applications to communication network design and ...
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In this paper we present an implementation of a generic memetic algorithm (MA) for the edge bi-connectivity augmentation problem (E2AUG). this problem is known for its applications to communication network design and in VLSI floor planning. Our starting point is a standard template for MA. We use a generic programming approach to obtain a C++ implementation of the MA template and instantiate it for the E2AUG problem. the implementation separates issues related to the memetic algorithm from those related to the E2AUG problem making thus possible (he reuse of the implementation for other problems. Moreover, the generic approach enabled us to easily implement the algorithm in parallel setting. We use known benchmarks in the literature for the problem to experimentally evaluate the implementation.
A remote view system is a system for the delivery and presentation of information such as video and audio to users in remote locations. Methods for the construction of virtual environments based on video information h...
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ISBN:
(纸本)9781467345651;9780769549033
A remote view system is a system for the delivery and presentation of information such as video and audio to users in remote locations. Methods for the construction of virtual environments based on video information have been applied to remote view technology. When a system that supports remote viewing is applied to situations such as viewing scenery or engaging in collaborative work, it is useful to provide users with a function that enables them to walk through a virtual environment. Although walkthroughs are possible in remote view systemsthat use pre-prepared images to construct virtual environments, these systems are lacking in terms of their real-time performance. In this study, we built a virtual walk-through environment that allows remote viewing based on images sent in real time from an omnidirectional camera. By using an improved map projection method, the system produces less image distortion than the conventional projection method. We have confirmed the walk-through capabilities of this system, evaluated the performance of improved map projection method, and subjected it to user trials.
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