In order to improve the speed and efficiency of dynamic route solution for traffic network, the paper constructs parallel simulation solution framework using distributed and parallel simulation technology and illumina...
ISBN:
(纸本)9781424417865
In order to improve the speed and efficiency of dynamic route solution for traffic network, the paper constructs parallel simulation solution framework using distributed and parallel simulation technology and illuminates parallel simulation strategy which master process assigns sub-task to slave process. At the same time, the parallel simulation algorithm and implemented process or dynamic route solution are designed in microscopic simulation level. It puts forwards network-partition algorithm based on each intersection and communication mode of synchronization between processes to realize dynamic load balancing. It expatiates on the parallelism of simulation module and simulation control of solution algorithm. With designed parallel algorithm, traffic network that is made up of 12 intersections is modeled on different numbers of processors. Results from the simulation demonstrate that simulation speed increases about 2.5 times. Hence, the designed parallel simulation algorithm provides a foundation for larger scale dynamic route solution.
A new parallel algorithm for finding the frequent itemsets in databases is presented. It differs fundamentally of well known Apriori algorithm, where at the beginning of every step, the dimension of the new frequent i...
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ISBN:
(纸本)9780769534725
A new parallel algorithm for finding the frequent itemsets in databases is presented. It differs fundamentally of well known Apriori algorithm, where at the beginning of every step, the dimension of the new frequent itemsets increases by I. In our algorithm the frequent itemsets are determined by progressively enlarging the interval which the individual items appertain, i.e. if at the k-th step the new candidates are from [i, i + k] intervals, i = 1, 2...., n - k, at the next step, k + 1 1, the new candidates will belong to [i, i + k + 1] intervals, i = 1, 2,..., n - k - 1. the frequent individual items are identified by their index. the basic idea is that the new frequent itemsets with individual items from the interval [i, j], simultaneously contain the items i and j. the frequent itemsets are built by sharing the work between n processors. Hereby, the processor P(i) computes, step by step, the sets F(i,j) of the frequent itemsets with individual items from the intervals [i, j], j i,..., n. In order to compute the set F(i,j), the processing unit Pi uses F(i,j-1) obtained in the previous step and F(i+1,j) received from the processor P(i+1). the main advantage of our parallel algorithm is that it uses a communication pattern known before algorithm start, which allows mapping communication to hardware. Another major advantage is that the set of the transactions can be distributed to processors prior to beginning. this is possible because a processor Pi has to compute F(i,j), j = i,..., n and therefore only the transactions containing the frequent item i are needed.
Group membership protocols in distributed systems enable entities in a group to be aware of all other entities in the group. this information is essential for the system to perform as a cohesive unit collaborating to ...
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parallel Discrete Event Simulation (PDES) and High Level Architecture (HLA) based distributed simulation need to collaborate to conquer the large-scale complex systems. PDES alms at making best use of supercomputing r...
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ISBN:
(纸本)9781424417865
parallel Discrete Event Simulation (PDES) and High Level Architecture (HLA) based distributed simulation need to collaborate to conquer the large-scale complex systems. PDES alms at making best use of supercomputing resources while HLA focus on the interoperability of geographically distributed independent simulations. this presents particular challenges on the Interoperability between PDES and HLA based simulation. this paper proposes a model mapping framework for mapping the Base Object Model (BOM) conceptual model definition into parallel discrete event simulation models, providing the common semantic basis with Federation Object Models (FOMs) that transformed from the same BOM. Withthe guide of this framework, the Entity Types, Event Types, Pattern of Interplay and State Machines could be mapped Into PDES simulation objects, events, event scheduling relationship, and state transition, respectively. A case study about social simulation indicates;that this approach not only makes the development of PDES models easy, but also facilitates the conceptual interoperability between PDES and HLA based distributed simulations.
As number and diversity of data, information and resources increase importance of usage of knowledge for their accessing and reuse grows significantly. One of the most useful approaches is based on semantic descriptio...
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ISBN:
(纸本)9780769534725
As number and diversity of data, information and resources increase importance of usage of knowledge for their accessing and reuse grows significantly. One of the most useful approaches is based on semantic description of elementary data and pieces of information as well as on relations between them, therefore resulting in ontological approach. Semantics is starting to be used in wider scope than ever, especially for accessing distributed resources. this field is well represented by the Semantic Web, where WWW content can be expressed also in a format that can be read and used by automated tools, thus permitting people and machines to find, share and integrate information more easily. Semantic description of services and user requests can also be used in (semi-)automatic construction of distributed/Grid applications, often in a form of workflows. In order to effectively manage ontologies on the level higher than the local one, e.g., using Virtual Organization approach some sort of knowledge base must be provided. In the lecture an overview of problems and advantages of this approach is given with focus on two different kinds of applications: the first resulting from high performance computing and the second - high throughput computing, making use of Service Oriented Architecture (SOA), supported by semantic description. Unification of semantic description of both services and resources through ontologies, as well as a proposal for organizational memory to enabling storing and accessing metadata, kept in the form of ontologies are also outlined. Virtual Organization creation by (semi-) automatic contract negotiation is discussed too. Practical examples concerning flood forecast simulation, automatic workflow construction and real-time computing to support the ATLAS experiment are presented, making use of the proposed semantic approach. they are based on collaborative work performed within several European funded projects, like Crossgrid (IST-200132243), K-WfGrid (FP6
In this work we consider the solution of 3D time domain electromagnetic inverse problems. Solving such problems is an open challenge as they require very high computational resources. We therefore explore a method to ...
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In this work we consider the solution of 3D time domain electromagnetic inverse problems. Solving such problems is an open challenge as they require very high computational resources. We therefore explore a method to parallelize the inverse problem by using time decomposition. We show that our approach can reduce the computational time although it does not scale optimally. (C) 2007 Published by Elsevier B.V. on behalf of IMACS.
the proceedings contain 48 papers. the topics discussed include: quicksilver scalable multicast (QSM);execution patterns in automatic malware and human-centric attacks;a fast and robust content-based publish/subscribe...
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ISBN:
(纸本)9780769531922
the proceedings contain 48 papers. the topics discussed include: quicksilver scalable multicast (QSM);execution patterns in automatic malware and human-centric attacks;a fast and robust content-based publish/subscribe architecture;network planning optimization for multimedia networks;user profile-based authorization policies for network QoS services;multicoordinated agreement protocols for higher availability;generalizing RDP codes Using the combinatorial method;flexible parameterization of XOR based codes for distributed storage;supporting concurrent task deployment wireless sensor networks;failure, disconnection and partition detection in mobile environment;cross-layer architecture for differentiated services in ad hoc networks;dynamic routing selection for wireless sensor networks;and fair-queued Ethernet for medical applications.
Grid schedulers which need to decide on which sites the jobs are best allocated require controlled and predictable service. Fair-share scheduling has become widely used but lacks a formal model and depends on the curr...
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A common programming model in distributed and grid computing is the client/server paradigm, where the client submits requests to several geographically remote servers for executing already deployed applications on its...
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ISBN:
(纸本)9783540681052
A common programming model in distributed and grid computing is the client/server paradigm, where the client submits requests to several geographically remote servers for executing already deployed applications on its own data. In this context it is mandatory to avoid unnecessary data transfer because the data set can be very large. this work addresses the problem of implementing a strategy for data management in case of data dependencies among subproblems in the same application. To this purpose, some minor changes have been introduced to the distributed Storage Infrastructure in NetSolve distributedcomputing environment.
Wireless sensor networks have many potential applications for both civil and military tasks. However, WSNs are susceptible to many types of attacks because they are deployed in open and unprotected environment. Select...
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