We present a novel state management mechanism that can be used to capture the complete execution state of distributed Python applications. this mechanism can serve as the foundation for a variety of dependability stra...
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ISBN:
(纸本)9781424416936
We present a novel state management mechanism that can be used to capture the complete execution state of distributed Python applications. this mechanism can serve as the foundation for a variety of dependability strategies including checkpointing, replication, and migration. Python is increasingly used for rapid prototyping parallel programs and, in some cases, used for high-performance application development using libraries such as NumPy. Building on Stackless Python and the River parallel and distributed programming environment, we have developed mechanisms for state capture at the language level. Our approach allows for migration and checkpointing of applications in heterogeneous environments. In addition, we allow for pre-emptive state capture so that programmers need not introduce explicit snapshot requests. Our mechanism can be extended to support application or domain-specific state capture. To our knowledge, this is the first general checkpointing scheme for Python. We describe our system, the implementation, and give some initial performance figures.
this paper presents first an analysis of a parallel connection of one synchronous generator and one self-excited induction generator, each coupled to its dc machine as well as a capacitor bank with a resistive load co...
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We present a parallel high-performance program that combines microscopic Molecular Dynamics (MD) with a mesoscopic Lattice Boltzmann (LB) method to simulate the translocation of biopolymers through nanometer size pore...
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ISBN:
(纸本)9781424416936
We present a parallel high-performance program that combines microscopic Molecular Dynamics (MD) with a mesoscopic Lattice Boltzmann (LB) method to simulate the translocation of biopolymers through nanometer size pores explicitly taking into account the interactions of the molecule withthe surrounding fluid. the parallel implementation exhibits excellent scalability on the BlueGene platform and includes techniques which may improve the flexibility and efficiency of other complex multi-physics applications.
In this paper a procedure is presented for locating single faults in N × N cube-type interconnection networks with global and withdistributed control. Networks withdistributed control are assumed to be based on...
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ISBN:
(纸本)0818656026
In this paper a procedure is presented for locating single faults in N × N cube-type interconnection networks with global and withdistributed control. Networks withdistributed control are assumed to be based on comparator cells with bit-serial architecture. It is shown that fault location requires eight tests for interconnection networks with global control under a functional fault model and four sets of test vectors for interconnection networks withdistributed control under the stuck-at fault model, given a specific implementation of the comparator cell. the outstanding feature of this procedure is that the input vectors are independent not only of the network size, but also of the actual fault location. thus, the fault location procedure can easily be implemented and has low time consumption.
Barrier algorithms are central to the performance of numerous algorithms on scalable, high-performance architectures. Numerous barrier algorithms have been suggested and studied for Non-Uniform Memory Access (NUMA) ar...
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ISBN:
(纸本)0818656026
Barrier algorithms are central to the performance of numerous algorithms on scalable, high-performance architectures. Numerous barrier algorithms have been suggested and studied for Non-Uniform Memory Access (NUMA) architectures, but less work has been done for Cache Only Memory Access (COMA) or attraction memory [1] architectures such as the KSR-1. In this paper, we presented two new barrier algorithms that offer the best performance we have recorded on the KSR-1 distributed cache multiprocessor. We discuss the trade-offs and the performance of seven algorithms on two architectures. the new barrier algorithms adapt well to a hierarchical caching memory model and take advantage of parallel communication offered by most multiprocessor interconnection networks,. Performance results are shown for a 256-processor KSR-1 and a 20-processor Sequent Symmetry.
this paper introduced a brand-new, paralleldistributed and extensible framework of 3D visualization system put forward by the author, which is based on JAVA techniques. the author designed parallel process method whi...
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ISBN:
(纸本)9780780397361
this paper introduced a brand-new, paralleldistributed and extensible framework of 3D visualization system put forward by the author, which is based on JAVA techniques. the author designed parallel process method which works together withthe terrain simplification algorithm to improve the speed of the 3d interactive system. As shown from the experiment results, the designed framework achieves a satisfying effect and a high efficiency when dealing withthe display of 3D visualization even with a huge data quantity, which owes to the mechanism of assorting the visualization algorithms on the Client side withthe data designation and transfer on the Server side.
An SPMD parallel implementation schema for divide-and-conquer specifications is proposed and derived by formal refinement (transformation) of the specification. the specification is in the form of a mutually recursive...
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ISBN:
(纸本)0818656026
An SPMD parallel implementation schema for divide-and-conquer specifications is proposed and derived by formal refinement (transformation) of the specification. the specification is in the form of a mutually recursive functional definition. In first phase, a parallel functional program schema is constructed which consists of a communication tree and a functional program that is shared by all nodes of the tree. the fact that this phase proceeds by semantics-preserving transformations in the Bird-Meertens formalism of higher-order functions guarantees the correctness of the resulting functional implementation. A second phase yields an imperative distributed SPMD implementation of this schema. the derivation process is illustrated with an example: a two-dimensional numerical integration algorithm.
the adoption of distributed database architectures for processing large data sets has shown to be an effective approach to reduce the response time of data analysis procedures. the same approach may be adopted on biol...
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ISBN:
(纸本)9781467372879
the adoption of distributed database architectures for processing large data sets has shown to be an effective approach to reduce the response time of data analysis procedures. the same approach may be adopted on biological databases, which comprise vast amounts of data that are analyzed to detect genetic diseases, to understand their causing factors and to design process-blocking substances. Defining how data will be fragmented over several network nodes, though, is a non-trivial task. In this work, we have applied a recently proposed methodology for distributed data allocation to create several topology scenarios in a cloud computing infrastructure aiming to improve the performance of data analysis procedures. the proposed scenarios were evaluated using modMine, which is an instance of the Intermine Datawarehouse, as case study.
Image segmentation is one of the most common steps in digital image processing. It classifies a digital image into different segments. there are many algorithms for image segmentation such as thresholding, edge detect...
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ISBN:
(纸本)9781509034352
Image segmentation is one of the most common steps in digital image processing. It classifies a digital image into different segments. there are many algorithms for image segmentation such as thresholding, edge detection, and region growing, which finding a suitable algorithm for medical image segmentation is a challenging task. this is due to noise, low contrast, and steep light variations of medical images. the main goal of this paper is improving the performance of fuzzy c-means clustering. Improving is achieved using parallel implementation of this algorithm. Fuzzy c-means clustering is an important iterative clustering algorithm, but it is computationally intensive and it uses the same data between the iterations. the center of the clusters changes in each iteration, which requires considerable amount of time for large data sets. the parallel fuzzy c-means clustering is implemented by using task pipeline concept in CUDA technology. the experimental results show that the performance is improved up to 23.35x. After that watershed algorithm is applied for the final segmentation. the implementation results show that the accuracy of diagnosis in magnetic resonance imaging 97/33% is improved. this improvement is achieved using enhancing edges and reducing noises in images.
this paper presents an efficient distributed dynamic channel allocation algorithm for mobile communications systems. the algorithm is based upon the mutual exclusion model, where the channels are grouped by the number...
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ISBN:
(纸本)076950728X
this paper presents an efficient distributed dynamic channel allocation algorithm for mobile communications systems. the algorithm is based upon the mutual exclusion model, where the channels are grouped by the number of cells in a cluster and each group of channels can not be shared concurrently within the cluster. We discuss the algorithm and prove its correctness. We also show that the algorithm requires at most (worst case) O(N-g * N(n)logN(n)) messages, where N-g is the number of groups and N-n is the number of neighbors. this is compared to Choy's algorithm which requires O(N-g(2) * N-n), where N-g is the number of groups. Our simulations experiments indicate that DDRA algorithm outperforms previous schemes. A 5% reduction in the denial rate, and a 10-30% reduction in the acquisition time channel were obtained using our algorithm when compared to previous algorithm.
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