DASUD (Diffusion Algorithm Searching Unbalanced Domains) is a totally distributed load-balancing algorithm which belongs to the nearest-neighbors class. DASUD detects unbalanced domains (a processor and its immediate ...
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DASUD (Diffusion Algorithm Searching Unbalanced Domains) is a totally distributed load-balancing algorithm which belongs to the nearest-neighbors class. DASUD detects unbalanced domains (a processor and its immediate neighbors) and corrects this situation by allowing load movements between non-connected processors. DASUD has been evaluated by comparison with two well-known nearest-neighbors load balancing strategies, namely, the GDE (Generalized Dimension Exchange) and the SID (Sender Initiated Diffusion) by considering a large set of initial load distributions. These distributions were applied to ring, tents and hypercube topologies, and the number of processors ranged from 8 to 128. From these experiments we have observed that DASUD outperforms the other strategies used in the comparison as it provides the best trade-off between the balance degree obtained at the final state and the number of iterations required to reach this state.
This paper presents the SEEDS simulation environment for the evaluation of distributed traffic control systems. Starting with an overview of the general simulator architecture, the software modules and the derived har...
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This paper presents the SEEDS simulation environment for the evaluation of distributed traffic control systems. Starting with an overview of the general simulator architecture, the software modules and the derived hardware architecture of the simulation environment are described with respect to performance requirements. The communication architecture of the SEEDS simulator is based on the CORBA standard and the DIS simulation protocol. With the SEEDS prototype simulating airport ground-traffic, performance measurements evaluating critical design and implementation decisions are described. The main aspects of the performance analysis are the attained application performance using CORBA and DIS as communication middleware, and the scalability of the overall approach. The evaluation shows the appropriateness of the design of the simulation environment and the derived hard- and software architecture, which is flexible and open to further extensions. Moreover the combination of CORBA and DIS provides a suited platform for distributed interactive simulation purposes because of the adequate performance, high scalability, and the high-level programming model which allows to rapidly develop and maintain complex distributed applications with high-performance requirements.
The GRISSLi coupling interface is a runtime library designed for the coupled computation of grid-based multidisciplinary applications. Established simulation programs, which are devoted to a single discipline, can be ...
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The GRISSLi coupling interface is a runtime library designed for the coupled computation of grid-based multidisciplinary applications. Established simulation programs, which are devoted to a single discipline, can be interconnected to a complex simulation system via the GRISSLi coupling interface without recoding the participating programs. We introduce a data model to establish the links between the (dynamic) grids and the attached coupling values in a single application program and to establish the mappings between grids and coupling values among different application programs. The user-specified consistency model is realized using asynchronous communication based on the MPI message passing standard. Efficient communication is achieved by pre-computing an optimized communication schedule and overlapping communication with computation. Flexible coupling algorithms with adaptive grids and branches are supported in GRISSLi. We have developed a prototype implementation, which provides language bindings in ANSI C and Fortran, and runs currently on IBM RS/6000 SP, Gray T3E, SGI Origin/Octane and HP-V Class. We verify the functionality and evaluate the performance of our library using an industry relevant pilot application, the steel strip production process.
Interval temporal logic (ITL) is a real-time logic for specifying and verifying real-time systems. In this paper, ITL is used to specify a concurrent real-time system: an assembly line which is an abstract model of in...
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Interval temporal logic (ITL) is a real-time logic for specifying and verifying real-time systems. In this paper, ITL is used to specify a concurrent real-time system: an assembly line which is an abstract model of industrial robot control systems. We can specify the abstract properties of the system in ITL as well as the system design using the executable subset of ITL, Tempura. Compared with other approaches, the first advantage of this methodology is that the concurrent real-time systems can be naturally specified in a true concurrent model rather than an interleaving model. The second is that the specification of the system design is executable so that the simulation can be obtained in the same formal framework. Therefore, both the properties of the system and the consistency of the specification can be checked before verification.
Development of multiple robot systems which solve complex and dynamic problems in parallel and distributed manners is one of the key issues in robotics research. The multiple robot systems require robust methods to id...
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Development of multiple robot systems which solve complex and dynamic problems in parallel and distributed manners is one of the key issues in robotics research. The multiple robot systems require robust methods to identify robots for collaborative behaviors. This paper proposes a method using omnidirectional vision sensors for the identification between the robots. In addition to the several advantages of the omnidirectional vision sensor as a vision of a mobile robot, the omnidirectional vision sensor brings a significant benefit for realizing collaborative behaviors in multiple robot systems. After discussing on the algorithm, this paper shows several simulation results and real experimental results in a real environment.
The proceedings contains 22 papers from the 12th workshop on parallel and distributedsimulation. Topics discussed include: concurrency analysis and conservative methods;optimistic methods;pseudorandom number generati...
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The proceedings contains 22 papers from the 12th workshop on parallel and distributedsimulation. Topics discussed include: concurrency analysis and conservative methods;optimistic methods;pseudorandom number generation;run-time support;simulating wireless systems;and simulating communication systems.
parallel Monte Carlo simulation requires reliable RNGs. For sequential machines, good generators exist. A is not at all trivial to find high-quality RNGs for parallel machines. In this paper we present a short review ...
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ISBN:
(纸本)0818684577
parallel Monte Carlo simulation requires reliable RNGs. For sequential machines, good generators exist. A is not at all trivial to find high-quality RNGs for parallel machines. In this paper we present a short review of the main concepts to produce random numbers on parallel processors and, further, we illustrate some phenomena that occur with parallelization.
In this paper, the relationship between the computational models of Object-Oriented Rewriting and parallel Discrete-Event simulation models is explored. A discrete-event simulation program in which several objects int...
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ISBN:
(纸本)0818683325
In this paper, the relationship between the computational models of Object-Oriented Rewriting and parallel Discrete-Event simulation models is explored. A discrete-event simulation program in which several objects interact with each other by exchanging messages may have a high degree of concurrency (which can be exploited using optimistic or conservative parallelsimulation methods). We report on some observations on using Rewriting Logic in the field of parallel Discrete Event simulations, and investigate how parallelsimulation applications can be expressed using Object-Oriented Rewriting.
parallel and distributed discrete-event simulation (PDES) is a critical technology for an important class of very large complicated simulation models. However, with few exceptions, the bulk of empirical work in PDES h...
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parallel and distributed discrete-event simulation (PDES) is a critical technology for an important class of very large complicated simulation models. However, with few exceptions, the bulk of empirical work in PDES has been on small models. Furthermore, synchronization behavior is frequently complicated, which makes it very difficult to analytically prove anything about the performance executing large models on large machines. Scalability analysis asks how the performance of a certain application behaves as the application problem size increases and the parallel architecture executing it increases.
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