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IEEE International Conference on High Performance Computing and Communications (HPCC)

作者： Panfeng Wang Yunfei Du Hongyi Fu Xuejun Yang Haifang Zhou National Laboratory for Parallel and Distributed Processing College of Computer National University of Defense Technology Changsha Hunan China

Application-level checkpointing is a promising technology in the domain of large-scale scientific computing. The consistency of global checkpoint must be carefully guaranteed in order to correctly restore the computation. Usually, some complex coordinated protocols are employed to ensure the consistency of global checkpoint, which require logging orphan or in-transit messages during checkpointing. These protocols complicate the recovery of the computation and increase the checkpoint overhead due to logging message. In this paper, a new method which ensures the consistency of global checkpoint by static analysis is proposed. The method identifies the safe checkpointing regions in MPI programs, where the global checkpoint is always strongly consistent. All checkpoints are located in those safe checkpoint regions. During checkpointing, the method will not log any messages and introduce no extra overhead. The method was implemented and integrated into ALEC, which is a source-to-source precompiler for automating application-level checkpointing. The experimental results show that our method is effective.

关键词： Checkpointing Algorithms Flow graphs Protocols Fault tolerance Fault tolerant systems parallel machines

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Compiler-Assisted Application-Level Checkpointing for MPI Programs

Compiler-Assisted Application-Level Checkpointing for MPI Pr...

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IEEE International Conference on distributed Computing Systems

作者： Xuejun Yang Panfeng Wang Hongyi Fu Yunfei Du Zhiyuan Wang Jia Jia National Laboratory for Parallel & Distributed Processing College of Computer National University of Defense Technology Changsha Hunan China

ISBN: (纸本)9781424431748

Application-level checkpointing can decrease the overhead of fault tolerance by minimizing the amount of checkpoint data. However this technique requires the programmer to manually choose the critical data that should be saved. In this paper, we firstly propose a live-variable analysis method for MPI programs. Then, we provide an optimization method of data saving for application-level check-pointing based on the analysis method. Based on the theoretical foundation, we implement a source-to-source pre-compiler (ALEC) to automate application-level checkpointing. Finally, we evaluate the performance of five FOR-TRAN/MPI programs which are transformed and integrated checkpointing features by ALEC on a 512-CPU cluster system. The experimental results show that i)the application-level checkpointing based on live-variable analysis for MPI programs can efficiently reduce the amount of checkpoint data, thereby decrease the overhead of checkpoint and restart;ii)ALEC is capable of automating application-level checkpointing correctly and effectively.

关键词： checkpointing message passing mannose phosphate isomerase remote procedure calls artificial lung expanding compound optimization method Checkpoints Computer personnel Fault tolerance application layer

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Load scheduling: Reducing Pressure on distributed Register files for free 08

Load scheduling: Reducing Pressure on Distributed Register f...

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2008 Asia and South Pacific Design Automation Conference (ASP-DAC 2008), part 1

作者： Mei Wen Nan Wu Maolin Guan Chunyuan Zhang National Laboratory for Parallel & Distributed Processing Chang Sha Hu Nan P.R. of China

ISBN: (纸本)9781424419227

In this paper we describe load scheduling, a novel method that balances load among register files by residual resources. Load scheduling can reduce register pressure for clustered VLIW processors with distributed register files while not increasing VLIW scheduling length. We have implemented load scheduling in compiler for Imagine and FT64 stream processors. The result shows that the proposed technique effectively reduces the number of variables spilled to memory, and can even eliminate it. The algorithm presented in this paper is extremely efficient in embedded processor with limited register resource because it can improve registers utilization instead of increasing the requirement for the number of registers.

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Study on numerical algorithm of 3D meso-mechanics model of dam concrete

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Jisuan Lixue Xuebao/Chinese Journal of Computational Mechanics 2008年第2期25卷 241-247页

作者： Ma, Huai-Fa Chen, Hou-Qun Wu, Jian-Ping Li, Bao-Kun China Institute of Water Resources and Hydropower Research Beijing 100044 China National Key Laboratory for Parallel and Distributed Processing Changsha 410073 China Beijing University of Technology Beijing 100044 China

On the meso-mechanics level the dam concrete is taken as the composite material consisting of aggregate, mortar and interface between them. A 3-dimensional finite element model of the dam concrete specimen is generated with consideration of damage evolutionary processes and strain-rate effects of the different media. The numerical computing algorithm and its FORTRAN serial program on PC computer for the nonlinear dynamic analysis of dam concrete were developed. The loading procedure can be controlled either by load or by displacement. In order to reduce the degree of freedom of the system, an artificial medium with mechanical properties equivalent to the composite media of the mortar and the finest aggregates were involved by using multi-scaled method. The numerical analyses for the specimens both of wet-sieved and full-graded dam concrete were carried out to investigate the failure processes under static and dynamic shock loading. The analytical results verified that the applied algorithm and its computer program are correct and effective. Based on the serial program, by using memory optimization for stiffness matrix and conjugate gradient (CG) algorithm with the preconditioner of incomplete Cholesky factorization with double threshold (ICT), the parallel program for Sun Fire 6800 server was developed. The computing efficiency was raised remarkably.

关键词： Concretes

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Modelling with relational calculus of object and component systems - RCOS

Modelling with relational calculus of object and component s...

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作者： Chen, Zhenbang Hannousse, Abdel Hakim Van Hung, Dang Knoll, Istvan Li, Xiaoshan Liu, Zhiming Liu, Yang Nan, Qu Okika, Joseph C. Ravn, Anders P. Stolz, Volker Yang, Lu Zhan, Naijun International Institute for Software Technology United Nations University China Faculty of Science and Technology University of Macau Department of Computer Science Aalborg University Denmark Lab. of Computer Science Institute of Software CAS China National Laboratory for Parallel and Distributed Processing China

ISBN: (纸本)3540852883

This chapter presents a formalization of functional and behavioural requirements, and a refinement of requirements to a design for CoCoME using the Relational Calculus of Object and Component Systems (rCOS). We give a model of requirements based on an abstraction of the use cases described in Chapter 3.2. Then the refinement calculus of rCOS is used to derive design models corresponding to the top level designs of Chapter 3.4. We demonstrate how rCOS supports modelling different views and their relationships of the system and the separation of concerns in the development. © 2008 Springer-Verlag Berlin Heidelberg.

关键词： Calculations

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distributed Line Graphs: A Universal Framework for Building DHTs Based on Arbitrary Constant-Degree Graphs

Distributed Line Graphs: A Universal Framework for Building ...

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International Conference on distributed Computing Systems

作者： Yiming Zhang Ling Liu Dongsheng Li Xicheng Lu National Laboratory for Parallel and Distributed Processing National University of Defense Technology Changsha China Georgia Institute of Technology College of Computing Georgia Institute of Technology Atlanta USA

ISBN: (纸本)9781424431748

Most proposed DHTs have their unique maintenance mechanisms specific to the static graphs on which they are based. In this paper we propose distributed line graphs (DLG), a universal framework for building DHTs based on arbitrary constant-degree graphs. We prove that in a DLG-enabled, N-node DHT, the out-degree is d, the in-degree is between 1 and 2d, and the diameter is less than 2(log d N-log d N 0 +D 0 +1), where d, D 0 and N 0 represent the degree, diameter and number of nodes of the initial graph, respectively. The maintenance cost of DLG-enabled DHTs is O(log d N). We show the power of DLG technique by applying it to Kautz graphs to propose a new DHT scheme.

关键词： Routing Maintenance engineering Buildings Distance measurement Topology Industries Construction industry

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Flexible Routing in Grouped DHTs

Flexible Routing in Grouped DHTs

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International Conference on Peer-to-Peer Computing

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

In most DHTs proposed so far, all nodes are assumed to be homogeneous, and all messages are routed using a common algorithm. In practice, however, nodes in large-scale systems might be heterogeneous with respect to their capabilities, reputations, affiliations of administrative domains, and so on, which consequently makes it preferable to distinguish the heterogeneity of participant nodes. To achieve this, in this paper we present grouped tapestry (GTap), a novel tapestry-based DHT that supports organizing nodes into groups and allows flexible DHT routing. The effectiveness of our proposals is demonstrated through theoretical analysis and extensive simulations.

关键词： Routing Fingers Peer to peer computing Maintenance engineering Security Availability Data structures

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An Efficient Approach for Point Coverage Problem of Sensor Network

An Efficient Approach for Point Coverage Problem of Sensor N...

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International Symposium on Electronic Commerce and Security

作者： GaoJun Fan Feng Liang ShiYao Jin National Laboratory of Parallel and Distributed Processing National University of Defense Technology Changsha Hunan China Military Representative Office of Navy Chinese Shipbuilding Company Limited Shanghai China

ISBN: (纸本)9780769532585

One fundamental issue in application of wireless sensor networks is to provide proper coverage of their deployment regions, which answers the questions about the quality of service (surveillance or monitoring) that can be provided by a sensor network. In this paper, we consider the point-coverage problem where a given set of n points requires to be covered in the two-dimension (such as monitoring leakage of hazardous gaseous materials at ventilation points or observing the fixed location important targets). Our objective is to place the minimal number sensors such that coverage points in the field can be covered by at least k sensors. By combining computational geometry and combinatorics techniques, we investigate the issue from a different angle, demonstrate an important relationship between coverage points and sensors, and develop an efficient algorithm for 1-coverage problem. Finally, we indicate our approach can easily solve k-coverage problem based on 1-coverage.

关键词： Wireless sensor networks Sensors Monitoring Ad hoc networks Tin Computational geometry Wireless communication

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An Efficient Approximation for Weapon-Target Assignment

An Efficient Approximation for Weapon-Target Assignment

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ISECS International Colloquium on Computing, Communication, Control, and Management, CCCM

作者： Lina Chen ChuanJun Ren Su Deng C4ISR Technology National Defense Science and Technology Key Laboratory National University of Defense Technology Changsha Hunan China National Laboratory of Parallel and Distributed Processing National University of Defense Technology Changsha Hunan China

The weapon-target assignment (WTA) problem is a fundamental problem arising in defense-related applications of operations research. The WTA problem can be formulated as a nonlinear integer programming problem and is known to be NP-complete. We present firstly a technique founded on the use weapon cell, which enables one-to-many mapping about weapon-target to become one-to-one mapping. Next, we introduce a framework of solving the WTA problem. Based on this framework, an approximation algorithm that is grounded on the rules about weapon cells and targets is proposed. Finally, the simulative results show that the proposed algorithm indeed is very efficient.

关键词： Weapons Heuristic algorithms Algorithm design and analysis Resource management Artificial neural networks Genetic algorithms Operations research

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Axiomatizing extended temporal logic fragments via instantiation

Axiomatizing extended temporal logic fragments via instantia...

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4th International Colloquium on Theoretical Aspects of Computing (ICTAC 2007)

作者： Liu, Wanwei Wang, Ji Dong, Wei Chen, Huowang National Laboratory of Parallel and Distributed Processing China

ISBN: (纸本)9783540752905

ETLs are temporal logics employing w-automata as temporal connectives. This paper presents sound and complete axiom systems for ETLl, ETLf, and ETLr, respectively. Axioms and rules reflecting temporal behaviors of looping, finite and repeating automaton connectives are provided. Moreover, by encoding temporal operators into automaton connectives and instantiating the axioms and rules relating to automaton connectives, one may derive axiom systems for given ETL fragments.

关键词： Temporal logic

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