Agent-based systems are inherently distributed and parallel by a distributed memory model, but agent-based simulation is often characterised by a shared memory model. this paper discusses the challenges of and solutio...
详细信息
ISBN:
(纸本)9789897585289
Agent-based systems are inherently distributed and parallel by a distributed memory model, but agent-based simulation is often characterised by a shared memory model. this paper discusses the challenges of and solution for large-scale distributed agent-based simulation using virtual machines. simulation of large-scale multi-agent systems with more than 10000 agents on a single processor node requires high computational times that can be far beyond the constraints set by the users, e.g., in real-time capable simulations. parallel and distributedsimulation involves the transformation of shared to a communication-based distributed memory model that can create a significant communication overhead. In this work, instead distributing an originally monolithic simulator with visualisation, a loosely coupled distributed agent process platform cluster network performing the agent processing for simulation is monitored by a visualisation and simulation control service. A typical use case of traffic simulation in smart city context is used for evaluation the performance of the proposed DSEJAMON architecture.
A distributed algorithm is introduced for the analysis of large continuous time Markov chains (CTMCs) by combining in some sense numerical solution techniques and simulation. CTMCs are described as a set of processes ...
详细信息
A distributed algorithm is introduced for the analysis of large continuous time Markov chains (CTMCs) by combining in some sense numerical solution techniques and simulation. CTMCs are described as a set of processes communicating via message passing. the state of a process is described by a probability distribution over a set of reachable states rather than by a single state. simulation is used to determine event times and messages types to be exchanged, whereas transitions are realized by vector matrix products as in iterative numerical analysis techniques. In this way, the state space explosion of numerical analysis is avoided, but it is still possible to determine more detailed results than withsimulation. parallelization of the algorithm is realized applying a conservative synchronization scheme, which exploits the possibility of precomputing event times as already proposed for parallelsimulation of CTMCs. In contrast to a pure simulation approach, the amount of computation is increased, whereas the amount of communication keeps constant. Hence it is possible to achieve even on a workstation cluster a significant speedup.
We present a conservative strategy for spatially decomposed parallel discrete event battlefield simulation. the traditional null message algorithm provides a foundation from which a mapping to generic simulation attri...
详细信息
We present a conservative strategy for spatially decomposed parallel discrete event battlefield simulation. the traditional null message algorithm provides a foundation from which a mapping to generic simulation attributes can be made. We informally discuss preservation of logical correctness and freedom from deadlock. Experimental results demonstrate the potential execution time savings when load imbalance is not dominant;more importantly, they highlight improvement opportunities in spite of potential load imbalance. the net result is that a very reasonable performance gain can be delivered for little effort in a way that supports good simulation system design principles. the approach is straightforward and can be easily implemented as part of a more general sequential or parallelsimulation support environment. While the approach is expressed in terms of battlefield simulation, its essence applies to many simulation applications.
We propose in this paper two new asynchronous parallel algorithms for test set partitioned fault simulation. the algorithms are based on a new two-stage approach to parallelizing fault simulation for sequential VLSI c...
详细信息
We propose in this paper two new asynchronous parallel algorithms for test set partitioned fault simulation. the algorithms are based on a new two-stage approach to parallelizing fault simulation for sequential VLSI circuits in which the test set is partitioned among the available processors. these algorithms provide the same result as the previous synchronous two stage approach. However, due to the dynamic characteristics of these algorithms and due to the fact that there is very minimal redundant work, they run faster than the previous synchronous approach. A theoretical analysis comparing the various algorithms is also given to provide an insight into these algorithms. the implementations were done in MPI and are therefore portable to many parallel platforms. Results are shown for a shared memory multiprocessor.
Multi-resolution representation of simulated entities is considered essential for a growing portion of distributedsimulations. Heretofore, modelers have represented entities at just one level of resolution, or have r...
详细信息
Multi-resolution representation of simulated entities is considered essential for a growing portion of distributedsimulations. Heretofore, modelers have represented entities at just one level of resolution, or have represented concurrent representations in an inconsistent manner. We address the question of the cost of maintaining multiple, concurrent representations. We present a brief overview of our concept of a Multiple Resolution Entity (MRE) and Attribute Dependency Graph (ADG) both originally described elsewhere, and then compare simulation and consistency costs of some approaches, including our own MRE/ADG-based approach, to multi-resolution modeling. the cost analysis presented here is the first known analysis of its type, and will provide a basis for simulation designers to determine the best, and most cost-effective approach to supporting simulation of entities at different levels of resolution concurrently.
In this paper we describe a novel approach for a concurrent numerical simulation of the unsteady flow within an idealised stenosed artery and a simplified blood clotting process based on a residence time model. the ap...
详细信息
ISBN:
(纸本)0769522815
In this paper we describe a novel approach for a concurrent numerical simulation of the unsteady flow within an idealised stenosed artery and a simplified blood clotting process based on a residence time model. the applied numerical scheme is the lattice Boltzmann technique, which proved to be highly efficient particularly for transient flows and complex or varying geometries.
We present a novel approach to parallel discrete event simulation based on the Cilk model of multithreaded computation. Cilk's runtime system not only manages the low-level aspects of program execution, but also p...
详细信息
We present a novel approach to parallel discrete event simulation based on the Cilk model of multithreaded computation. Cilk's runtime system not only manages the low-level aspects of program execution, but also provides the user with an algorithmic model of performance which can be used to predict the execution time of a parallelsimulation. Moreover, a Cilk application can `scale down' to run on a single processor with nearly the same performance as that of serial code. A conservative parallel discrete event simulation algorithm has been developed in which communication between logical processes is achieved using Cilk's virtual memory model, dag consistent shared memory. the simulation executes in cycles, where each cycle involves a divide and conquer computation. Although local lookahead information can be exploited, the algorithm is robust in that it also calculates a global simulation time for each cycle. It can therefore be used for applications where zero lookahead may occur.
In autonomous distributed robot systems, many robots cooperate together to carry out many difficult tasks that single robot can not realize. But, in order to cooperate together the robots should communicate with each ...
详细信息
ISBN:
(纸本)0769522815
In autonomous distributed robot systems, many robots cooperate together to carry out many difficult tasks that single robot can not realize. But, in order to cooperate together the robots should communicate with each other therefore, the communication among robots is very important problem to be solved In this paper, we propose an Adaptive Reservation-Time Division Multiple Access (AR-TDMA) medium access control protocol. We carried out computer simulation to evaluate the performance of proposed method the simulation results show that the proposed protocol has better scalability characteristics and object transportation time compared with a conventional protocol.
this paper presents a method towards easier evaluation of a large number of different image/video content descriptors, by using a multiple descriptor-tree based parallel indexing scheme instead of classical index stru...
详细信息
ISBN:
(纸本)9781479909568;9781479909551
this paper presents a method towards easier evaluation of a large number of different image/video content descriptors, by using a multiple descriptor-tree based parallel indexing scheme instead of classical index structures with high dimensional multi-feature vectors. We will show that the proposed scheme is flexible and easily extensible, and it is not just faster to build, but provides good retrieval precision as well. the primary goal is to provide a flexible and modular indexing scheme for descriptor evaluation and feature selection purposes, but it can be used for generic content-based retrieval tasks as well.
暂无评论