Modeling and testing for parallel software systems is difficult, because the number of states and execution fragments expand significantly caused by parallel behaviors, so that many traditional testing methods cannot ...
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ISBN:
(纸本)9780769548791
Modeling and testing for parallel software systems is difficult, because the number of states and execution fragments expand significantly caused by parallel behaviors, so that many traditional testing methods cannot work effectively for this kind of software. In this paper, a test sequence generation method based on model reduction for parallel software systems is shown. Firstly, a formal model for software system specification is constructed based on Coloured Petri Net (CPN), called system model;and a model reduction method based on trace-equivalent principle is shown and applied on system model, which could generate an external behavior equivalent model with smaller scale. Secondly, a linear behavior sequence of the system is specified using CPN, called LBS model, which represents testing purpose in a test case, and some operations between state space diagrams of system model and LBS model are defined, so that a sub-graph of system model state space diagram is generated, which could cover all executions of system model that involves behaviors of LBS. Finally, a performance analysis shows the effectiveness of the method.
Supercomputing on the heterogeneous architectures that integrate multi-core or many-cores processors has been developed at a dramatically speed. It is widely used in theoretical physics, theoretical chemistry, climate...
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ISBN:
(纸本)9780769548791
Supercomputing on the heterogeneous architectures that integrate multi-core or many-cores processors has been developed at a dramatically speed. It is widely used in theoretical physics, theoretical chemistry, climate modeling, biology simulation and medicine research for high-performance and energy-efficient computing. Yet it is still a big challenge to users when trying to run their scientific applications efficiently on large-scale supercomputers constructed by using heterogeneous multiprocessors. On the other hand, overhead cost issues of a large supercomputer for its resource managements, job scheduling, and system reliability become more and more important. In this paper, LPFSC, a light weight parallel framework for supercomputing, is presented, which helps programmers in planning their tasks on a supercomputer. In a huge supercomputer system, there might be a hundred of thousands of nodes, over a million processor cores and many other kinds of processors, general main-slave computing mode can hardly handle the huge amount of heterogeneous processors. LPFSC consists of modules for multiple master-slave support, load balance among huge amount computing tasks, and reliability support. Additional features will be added in the near future and it is supposed to provide good support for large heterogeneous computer systems. Finally, large amount tasks of 2D-FFT in varying size are tested under the framework for evaluation, which can scale to more than 300 processors.
this paper discusses lung cancer detection in chest X-ray images with a parallel genetic algorithm (GA). the template matching method and local search techniques are combined to the algorithm and JavaSpaces is used to...
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ISBN:
(纸本)9780769548791
this paper discusses lung cancer detection in chest X-ray images with a parallel genetic algorithm (GA). the template matching method and local search techniques are combined to the algorithm and JavaSpaces is used to construct the parallel system. the promising results are presented in the experiments.
D-ReServE increases reliability of SOA-based systems in case of failure occurrence. the fault-tolerant information in D-ReServE is stored in the Stable Storage, which available space depletes with time. thus, in this ...
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ISBN:
(纸本)9780769548791
D-ReServE increases reliability of SOA-based systems in case of failure occurrence. the fault-tolerant information in D-ReServE is stored in the Stable Storage, which available space depletes with time. thus, in this paper we propose a garbage collection protocol for D-ReServE that allows the periodic purging of the Stable Storage, and discuss the challenges of garbage collection due to the nature of SOA systems.
the snapshot problem addresses a collection of important algorithmic issues related to the distributed computations, which are used for debugging or recovering the distributed programs. Among the existing solutions, C...
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ISBN:
(纸本)9780769548791
the snapshot problem addresses a collection of important algorithmic issues related to the distributed computations, which are used for debugging or recovering the distributed programs. Among the existing solutions, Chandy and Lamport propose a simple distributed algorithm. In this paper, we explore the correct-by-construction process to formalize the snapshot algorithms in distributed system. the formalization process is based on a modeling language Event B, which supports a refinement-based incremental development using RODIN platform. these refinement-based techniques help to derive a correct distributed algorithm. Moreover, we demonstrate how this class of other distributed algorithms can be revisited. A consequence is to provide a fully mechanized proof of the distributed algorithms.
Assume that each vertex of an arbitrary n-vertex tree T is assigned a nonnegative integer weight. this paper considers partitioning the vertices of tree T into p disjoint clusters such that the total weight of each cl...
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ISBN:
(纸本)9780769548791
Assume that each vertex of an arbitrary n-vertex tree T is assigned a nonnegative integer weight. this paper considers partitioning the vertices of tree T into p disjoint clusters such that the total weight of each cluster is at least l and at most u, where l and u are given integers with lthms for trees only allow that a cluster corresponds to a subtree, our algorithm also considers clusters containing several subtrees as long as these subtrees have the same parent node or their root vertices are adjacent siblings. We call this [l, u] sibling partitioning. We deal with two problems of [l, u] sibling partitioning for a given tree: the minimal partition problem is to find an [l, u] sibling partitioning withthe minimum number of clusters;the p-partition problem is to find an [l, u] sibling partitioning with a given number p of clusters. In this paper, we present the first polynomial-time algorithm to solve the two problems.
Capabilities are a more scalable and adaptive access control approach compared withthe conventional approaches such as ACLs, due to their being held and managed by users or agents in systems, but not the middleware. ...
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ISBN:
(纸本)9780769548791
Capabilities are a more scalable and adaptive access control approach compared withthe conventional approaches such as ACLs, due to their being held and managed by users or agents in systems, but not the middleware. this feature makes capabilities more suitable in distributed environments that have dynamic populations. Treaties have been proposed to enhance the capability approach by introducing sequences of actions, such that treaties can capture characteristics of behaviours, and provide finer control over accesses. However there is a new problem brought by the behaviour modeling of treaties which is called duplication problem, which concerns preventing users from gaining unauthorised behaviour by duplicating treaties. In this paper we discuss this problem and propose three models of treaty systems that aim to solve the duplication problem.
Explicit model-checking (MC) is a classical solution to find flaws in a security protocol. But it is well-known that for non trivial protocols, MC may enumerate state-spaces of astronomical sizes-the famous state-spac...
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ISBN:
(纸本)9780769548791
Explicit model-checking (MC) is a classical solution to find flaws in a security protocol. But it is well-known that for non trivial protocols, MC may enumerate state-spaces of astronomical sizes-the famous state-space explosion problem. distributed model checking is a solution but complex and subject to bugs: a MC can validate a model but miss an invalid state. In this paper, we focus on using a verification condition generator that takes annotated distributed algorithms and ensures their termination and correctness. We study five algorithms (one sequential and four distributed where three of them are dedicated and optimised for security protocol) of state-space construction as a first step towards mechanised verification of distributed model-checkers.
this paper characterizes distributed XML processing on networking nodes. XML documents are sent from a client node to a server node through relay nodes, which process the documents before arriving at the server. Accor...
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ISBN:
(纸本)9789898565082
this paper characterizes distributed XML processing on networking nodes. XML documents are sent from a client node to a server node through relay nodes, which process the documents before arriving at the server. According as the node topology, the XML documents are processed in a pipelining manner or a parallel fashion. We evaluate distributed XML processing with synthetic and realistic XML documents on real and virtual environments. Characterization of well-formedness and grammar validation processing via pipelining and parallel models reveals inherent advantages of the parallel processing model.
Energy consumption has increasingly become a serious problem in contemporary data centers. the electricity bill contributes a significant fraction of the Total Cost of Ownership (TCO), and it has been predicted to inc...
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ISBN:
(纸本)9780769548791
Energy consumption has increasingly become a serious problem in contemporary data centers. the electricity bill contributes a significant fraction of the Total Cost of Ownership (TCO), and it has been predicted to increase at an even faster pace in the following years. In an attempt to reduce the energy consumption in cloud infrastructures, we propose REST, an energy-efficient cloud storage built upon an open source cluster-based object store similar to GFS. It achieves high energy-efficiency by cleverly exploiting the redundancy and its asymmetric accesses existing in the system without compromising inherent well-established mechanisms, while maintaining reasonable performance level. By slightly altering the data-layout policy, REST can safely keep a large amount of redundant storage nodes in standby mode or even powered off most of the time. Deploying a sophisticated real-time workload monitor, it provides flexibility to power up standby or powered down nodes to accommodate the variations in workloads. In addition, trade-offs between energy and performance can be conveniently made by simply adjusting a trade-off metric in REST. the FileBench experimental results have demonstrated that power savings can be as high as 29%, still providing comparable or even better performance.
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