检索结果-内蒙古大学图书馆

Optimization approaches of organizing streams on imagine processor

Jisuanji Xuebao/Chinese Journal of computers 2008年第7期31卷 1092-1100页

作者： Yang, Xue-Jun Zeng, Li-Fang Deng, Yu Tang, Yu-Hua National Key Laboratory of Parallel and Distributed Processing School of Computer Science National University of Defense Technology Changsha 410073 China Jiangnan Remote Sensing Institute Shanghai 200072 China

Due to the characteristics of stream applications and the insufficiency of conventional processors when running stream programs, stream processors which support data-level parallelism become the research hotspot. This paper presents two means, stream partition (SP) and stream compression (SC), to optimize streams on Imagine. The results of simulation show that SP and SC can make stream applications take full advantage of the parallel clusters, pipelines and three-level memory hierarchy of the Imagine processor, and then reduce the execution time of stream programs.

关键词： parallel processing systems

来源：评论

学校读者我要写书评

暂无评论

Collaborative search in large-scale unstructured peer-to-peer networks

Collaborative search in large-scale unstructured peer-to-pee...

引用

36th International Conference on parallel processing in Xi'an, ICPP

作者： Zhang, Yiming Li, Dongsheng Chen, Lei Lu, Xicheng National Laboratory for Parallel and Distributed Processing NUDT Department of Computer Science Hong Kong University of Science and Technology

ISBN: (纸本)076952933X

Searching in large-scale unstructured peer-to-peer networks is challenging due to the lack of effective hint information to guide queries. In this paper, we propose POP, a parallel, cOllaborative and Probabilistic search mechanism, in which query messages are viewed as search units to collaborate with each other and aggregate the distributed hints during the search process. A scheme called distributed Bloom Filter (DBF) is presented to propagate the hints with a bandwidth-aware manner, in which a node divides the received Bloom filter vector into subvectors and disseminates the fragments to its neighbors according to their bandwidth capacity. The effectiveness of POP is demonstrated through theoretical analysis and extensive simulations. © 2007 IEEE.

关键词： Bandwidth

来源：评论

学校读者我要写书评

暂无评论

The fault tolerant parallel algorithm: The parallel recomputing based failure recovery

The fault tolerant parallel algorithm: The parallel recomput...

引用

16th International Conference on parallel Architecture and Compilation Techniques, PACT 2007

作者： Yang, Xuejun Du, Yunfei Wang, Panfeng Fu, Hongyi Jia, Jia Wang, Zhiyuan Suo, Guang National Laboratory for Paralleling and Distributed Processing School of Computer National University of Defense Technology Changsha Hunan 410073 China

ISBN: (纸本)0769529445

This paper addresses the issue of fault tolerance in parallel computing, and proposes a new method named parallel recomputing. Such method achieves fault recovery automatically by using surviving processes to recompute the workload of failed processes in parallel. The paper firstly defines the fault tolerant parallel algorithm (FTPA) as the parallel algorithm which tolerates failures by parallel recomputing. Furthermore, the paper proposes the inter-process definition-use relationship analysis method based on the conventional definition-use analysis for revealing the relationship of variables in different processes. Under the guidance of this new method, principles of fault tolerant parallel algorithm design are given. At last, the authors present the design of FTPAs for matrix-matrix multiplication and NPB kernels, and evaluate them by experiments on a cluster system. The experimental results show that the overhead of FTPA is less than the overhead of checkpointing. © 2007 IEEE.

关键词： parallel algorithms

来源：评论

学校读者我要写书评

暂无评论

Compositional Verification of UML Dynamic Models

Compositional Verification of UML Dynamic Models

引用

Asia-Pacific Conference on Software Engineering

作者： Wei Dong Ji Wang Zhichang Qi Ni Rong School of Computer National University of Defense Technology China National Laboratory for Parallel and Distributed Processing China

UML dynamic models are important for software analysis and design. Verifying UML dynamic models to find design errors earlier is a key issue for ensuring software quality. Because of the characteristics such as concurrency and hierarchy, model checking of UML Statecharts and collaboration diagrams faces the problem of state explosion. In this paper, UML Statecharts is firstly structurally expressed by hierarchical automata and its semantics for open systems is introduced. Then, the synchronization composition of objects in UML collaboration diagrams is expatiated, based on which the global system behaviors can be constructed. Based on hierarchical automata and simulation relation between semantics structures, the compositional rules for verifying concurrent object systems are proposed. It makes possible that the construction of global state space will be unnecessary in model checking of UML collaboration diagrams. The hierarchical structures of UML Statecharts are also brought into the compositional verification, which makes the model checking of implementation models can be carried out through replacing detailed components by abstract specifications.

关键词： Unified modeling language Concurrent computing Automata State-space methods Explosions International collaboration Software systems Software engineering distributed computing Laboratories

来源：评论

学校读者我要写书评

暂无评论

Are filter methods very effective in gene selection of microarray data?

Are filter methods very effective in gene selection of micro...

引用

IEEE International Conference on Bioinformatics and Biomedicine Workshops (BIBMW)

作者： Zhou-Jun Li Li-Juan Zhang Huo-Wang Chen School of Computer Science & Engineering Beihang University Beijing China National Laboratory for Parallel and Distributed Processing Changsha China

Feature (gene) selection is a frequently used preprocessing technology for successful cancer classification task in microarray gene expression data analysis. Widely used gene selection approaches are mainly focused on the filter methods. Filter methods are usually considered to be very effective and efficient for high-dimensional data. This paper reviews the existing filter methods, and shows the performance of the representative algorithms on microarray data by extensive experimental study. Surprisingly, the experimental results show that filter methods are not very effective on microarray data. We analyze the cause of the result and provide the basic ideas for potential solutions.

关键词： Filters Data analysis Classification algorithms Cancer Algorithm design and analysis computer science Data engineering Laboratories distributed processing Gene expression

来源：评论

学校读者我要写书评

暂无评论

The Fault Tolerant parallel Algorithm: the parallel Recomputing Based Failure Recovery 07

The Fault Tolerant Parallel Algorithm: the Parallel Recomput...

引用

International Conference on parallel Architecture and Compilation Techniques (PACT)

作者： Xuejun Yang Yunfei Du Panfeng Wang Hongyi Fu Jia Jia Zhiyuan Wang Guang Suo National Laboratory for Paralleling and Distributed Processing School of Computer National University of Defense Technology Changsha Hunan China

ISBN: (纸本)9780769529448

关键词： Fault tolerance parallel algorithms Checkpointing Algorithm design and analysis High performance computing Scientific computing Concurrent computing parallel processing Large-scale systems Application software

来源：评论

学校读者我要写书评

暂无评论

Collaborative Search in Large-scale Unstructured Peer-to-Peer Networks

Collaborative Search in Large-scale Unstructured Peer-to-Pee...

引用

International Conference on parallel processing (ICPP)

作者： Yiming Zhang Dongsheng Li Lei Chen Xicheng Lu National Laboratory for Parallel and Distributed Processing National University of Defense Technology China Department of Computer Science Hong Kong University of Science and Technology Hong Kong China

Searching in large-scale unstructured peer-to-peer networks is challenging due to the lack of effective hint information to guide queries. In this paper, we propose POP, a parallel, collaborative and Probabilistic search mechanism, in which query messages are viewed as search units to collaborate with each other and aggregate the distributed hints during the search process. A scheme called distributed Bloom filter (DBF) is presented to propagate the hints with a bandwidth-aware manner, in which a node divides the received Bloom filter vector into subvectors and disseminates the fragments to its neighbors according to their bandwidth capacity. The effectiveness of POP is demonstrated through theoretical analysis and extensive simulations.

关键词： Large-scale systems Peer to peer computing Bandwidth Information filtering Information filters Analytical models Aggregates Space technology International collaboration Laboratories

来源：评论

学校读者我要写书评

暂无评论

Game-based axiomatization of μ-calculus

引用

Jisuanji Yanjiu yu Fazhan/computer Research and Development 2007年第11期44卷 1896-1902页

作者： Liu, Wanwei Wang, Ji Chen, Huowang National Laboratory of Parallel and Distributed Processing School of Computer Science National University of Defense Technology Changsha 410073 China

With the never-ending growth of the complexity of modern hardware and software systems, more and more sophisticated methods of verification are required. Model checking has been proved to be an effective approach to guaranteeing the correctness of design and implementation of software and hardware system. Model and temporal logics are used as specification languages in software and hardware verification. Modal μ-calculus is an extremely popular and important one among these logics. It is succinct in syntax and powerful in expressiveness. Since Kozen's paper on modal μ-calculus, it has received ever growing interest in both theoretical and application aspects. Based on the focus game theory, Lange and Stirling proposed the axiom systems for LTL and CTL. This paper extends that idea to that for modal μ-calculus. A game-theoretic approach is presented to test the satisfiability of modal μ-calculus formulas. In addition, this approach converts the satisfiability problem for μ-calculus into a solving problem for focus games. Consequently, based on these game rules, an axiom system for μ-calculus is developed, and the completeness of this deductive system can be proved via the game based satisfiability testing procedure. By comparison, this axiom system is much more intuitive and succinct than the existing μ-calculus axiom systems.

关键词： Temporal logic

来源：评论

学校读者我要写书评

暂无评论

Multi-replica clustering management method based on limited-coding

引用

Ruan Jian Xue Bao/Journal of Software 2007年第6期18卷 1456-1467页

作者： Zhou, Jing Wang, Yi-Jie Li, Si-Kun School of Computer National University of Defense Technology Changsha 410073 China National Key Laboratory for Parallel and Distributed Processing National University of Defense Technology Changsha 410073 China

In this paper, according to the resource management problems brought by a large number of replicas, a multi-replica clustering management method based on limited-coding is proposed. In this method, according to the process of creating new replicas from existent single replica, replicas are partitioned into different hierarchies and clusters. Then replicas are coded and managed based on the user-defined limited-coding rule consisting of replica hierarchy and replica sequence, which can also dispose the alteration of clusters caused by dynamic adjustments on replicas (replica addition or replica removal) effectively. After that, a management model of centralization in local and peer to peer in wide area is adopted to organize replicas, and the cost of reconciling consistency can be greatly depressed combining with defined minimal-time of update propagation. The relevance between the coding rule and the number of replicas, and the solutions to replica failure and replica recover are discussed. The results of the performance evaluation show that the clustering method is an efficient way to manage a large number of replicas, achieving good scalability, not sensitive to moderate node failure, and adapting well to applications with frequent updates.

关键词： Data processing

来源：评论

学校读者我要写书评

暂无评论

Two layered P2P model for semantic service discovery

引用

Ruan Jian Xue Bao/Journal of Software 2007年第8期18卷 1922-1932页

作者： Liu, Zhi-Zhong Wang, Huai-Min Zhou, Bin Institute of Network and Information Security School of Computer National University of Defense Technology Changsha 410073 China National Laboratory for Parallel and Distributed Processing School of Computer National University of Defense Technology Changsha 410073 China

In open Internet environment, it is inevitable that multiple ontologies coexist. Centralized service discovery mechanism becomes the bottleneck of SOC (service oriented computing), which results in poor scalability of system. Aiming at solving these problems, a two layered P2P based model for semantic service discovery is proposed in this paper. The model is based on ontology community and integrates iVCE (Internet-based virtual computing environment) core concepts into a P2P model. Based on this model, a service discovery algorithm composed of two stages and three steps is proposed. It matches services across communities as well as within community. Within a community, algorithm locates registers holding service information with a high probability of satisfying a request firstly. Then it captures semantic matching between service advertisements and service requests by logical reasoning. Service discovery across communities occurs according to some policies. The model is suitable for opening environment with coexistent multiple ontologies. Experimental results show that given an appropriate setting, the model can make a tradeoff between recall and responding time. In addition, the model will release the mean load of registers efficiently while holding recall.

关键词： Semantics

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：