The paper presents an approach for achieving better performance of Monte Carlo simulation by implementing the process in a distributed computing environment. The simulation process is analyzed and sub processes, suita...
详细信息
ISBN:
(纸本)9789549641523
The paper presents an approach for achieving better performance of Monte Carlo simulation by implementing the process in a distributed computing environment. The simulation process is analyzed and sub processes, suitable for parallel execution are defined. The proposed approach is demonstrated by applying Monte Carlo simulation for evaluating the market risk of a financial position in an experimental distributed computing environment. Comparison data, obtained by carrying out the same simulation in an environment with one computer and in distributed environment, are presented and analyzed.
Remote network emulation is an approach that utilizes a remote parallel simulator to improve the scale and accuracy of network emulation for general users with no local access to high performance computing facilities....
详细信息
ISBN:
(纸本)9780769531595
Remote network emulation is an approach that utilizes a remote parallel simulator to improve the scale and accuracy of network emulation for general users with no local access to high performance computing facilities. The remote network emulation approach involves using a large scale detailed packet level simulation at a remote site in conjunction with a local network emulation to quickly provide QoS predictions to real time applications. Model update algorithms are needed to keep the remote simulator and local emulator updated with each other's status, while keeping the amount of communication required to an acceptable level. In this paper two adaptive model update algorithms are explored for triggering network status updates. The first algorithm dynamically adjusts update frequency according to the real network status between the remote simulator and emulator. The second algorithm triggers updates whenever the prediction error of the network emulation exceeds a pre-set threshold. Preliminary experimental results show that the two algorithms can improve emulation accuracy compared with a fixed update algorithm for the scenarios that were tested.
In this paper we describe web-based distributed system suitable for acceleration of fault simulation in digital circuits. Framework has three-tier client server concept. Java applets are used for user interfaces. Java...
详细信息
ISBN:
(纸本)9781424422760
In this paper we describe web-based distributed system suitable for acceleration of fault simulation in digital circuits. Framework has three-tier client server concept. Java applets are used for user interfaces. Java servlet on master server supports communication, task partitioning, user tracking, data management, etc. HTTP protocol based solution is used, since it is well established and flexible in firewall-protected environments. Reuse of existing test tools by encapsulation into Java agents extends the lifecycle and value of these tools. Considerable fault simulation speedup was gained in experiments. Two types of fault set partitioning were tried: adjacent fault selection and random fault selection. The latter is able to ensure more equal execution times for subtasks and therefore contributes to overall shorter parallelsimulation time.
The proceedings contain 11 papers. The topics discussed include: reproducible testing of distributed software with middleware virtualization and simulation;dynamic testing of flow graph based parallel applications;sch...
ISBN:
(纸本)9781605580524
The proceedings contain 11 papers. The topics discussed include: reproducible testing of distributed software with middleware virtualization and simulation;dynamic testing of flow graph based parallel applications;scheduling considerations for building dynamic verification tools for MPI;memory tagging in Charm++;support for symmetric shadow memory in multiprocessors;on-the-fly race detection in multi-threaded programs;AtomRace: data race and atomicity violation detector and healer;towards a better collaboration of static and dynamic analyses for testing concurrent programs;software development tools for multi-core/parallel programming;systematic concurrency testing using CHESS;and pitfalls in teaching development and testing of concurrent programs and how to overcome them.
The proceedings contain 22 papers. The topics discussed include: time Jails: a Hybrid Approach to Scalable Network Emulation;Adaptive Model Update Algorithms for Remote Network Emulation;toward Scalable Routing Experi...
详细信息
ISBN:
(纸本)9780769531595
The proceedings contain 22 papers. The topics discussed include: time Jails: a Hybrid Approach to Scalable Network Emulation;Adaptive Model Update Algorithms for Remote Network Emulation;toward Scalable Routing Experiments with Real-Time Network simulation;modeling and simulation of Pedestrian Behaviors;parallel and distributed Spatial simulation of Chemical Reactions;secure Referee Selection for Fair and Responsive Peer-to-Peer Gaming;stochastic Process Models for Packet/Analytic-Based Network simulations;performance Analysis of Real Traffic Carried with Encrypted Cover Flows;an Algorithm Selection Approach for simulation Systems;Symbiotic simulation Systems: an Extended Definition Motivated by Symbiosis in Biology;evaluating the Performance of Real Time Videoconferencing in Ad Hoc Networks Through Emulation;and scalable versus Accurate Physical Layer Modeling in Wireless Network simulations.
distributed Virtual Environments (DVEs) such as online games, military simulations or collaborative design are currently very popular. To support large-scale DVEs, an architecture with multiple, geographically distrib...
详细信息
ISBN:
(纸本)9780769525877
distributed Virtual Environments (DVEs) such as online games, military simulations or collaborative design are currently very popular. To support large-scale DVEs, an architecture with multiple, geographically distributed servers is usually employed, and the virtual world is partitioned into multiple zones for load distribution. The client assignment problem arises when assigning the participating clients to the servers. Current approaches usually assign clients to servers based on a resource-driven approach, i.e. the only concern is not to overload the servers. This approach may degrade the interactivity of DVEs if the network delay from a client to its assigned server is large. In this paper, we formulate the client assignment problem, and propose three new algorithms to assign clients to servers in a more efficient way. The proposed algorithms are based on the greedy heuristics developed for the well-known Terminal Assignment problem. From extensive simulation studies with realistic settings, we find that even under heterogeneous environments such as the Internet where accurate input data for the assignment algorithms are usually impractical to obtain, some of the proposed algorithms are still beneficial to the performances of DVEs.
parallel Discrete Event simulation (PDES) allows to speed up the execution of a simulation by distributing the simulation's workload between multiple processors. The mapping of the simulation entities over the pro...
详细信息
ISBN:
(纸本)9789549641523
parallel Discrete Event simulation (PDES) allows to speed up the execution of a simulation by distributing the simulation's workload between multiple processors. The mapping of the simulation entities over the processors is very important with regard to the efficiency of the overall process of simulation. This paper presents an approach for automation of the process of mapping over distributed environment (network of workstations) for optimistic simulation based on the synchronization protocol Time Warp.
This paper introduces a radically different approach to parallelsimulation for gate level design, aimed at completely eliminating the communication and synchronization overhead between simulators. It is based on a ne...
详细信息
It is essential to evaluate the performance of newly developed distributed software and network protocols. Network emulation enables reproducible evaluation of unmodified real implementations. Software built for distr...
详细信息
ISBN:
(纸本)9780769531595
It is essential to evaluate the performance of newly developed distributed software and network protocols. Network emulation enables reproducible evaluation of unmodified real implementations. Software built for distributed systems, such as a large scale peer-to-peer system, requires evaluation scenarios with thousands of communicating nodes. Two approaches for scaling network emulation to such scenario sizes have been proposed in the literature: node virtualization and time virtualization. Node virtualization allows maximizing the utilization of standard hardware used for emulation experiments. Time virtualization enables trading experiment duration for virtually increased resources of the hardware. It stands to reason that a combination of those two approaches may increase scalability even further. However, in existing combinations, either node virtualization implies relatively high overhead or time virtualization requires modifications of the test subject implementation. In this paper, we present a novel hybrid approach called Time Virtualized Emulation Environment (TVEE). It integrates node virtualization with low overhead and time virtualization, which is transparent to the execution of test subjects. We introduce virtual time based on epochs to enable better dynamic hardware utilization during long lasting experiments. Additionally, a mechanism similar to soft timers ensures an accurate reproduction of network properties in the time virtualized emulation. Our evaluations show the accuracy and scalability of time virtualized network emulation. Comparing TCP throughput, TVEE outperforms other approaches using an event based virtual time by an order of magnitude.
parallel discrete event simulation (PDES) is a basic approach for evaluation of complex systems. A PDES attempts to speed up the execution of a simulation by distributing the simulation's workload between multiple...
详细信息
ISBN:
(纸本)9789549641523
parallel discrete event simulation (PDES) is a basic approach for evaluation of complex systems. A PDES attempts to speed up the execution of a simulation by distributing the simulation's workload between multiple processors. A network of workstations is a widely available platform for PDES. The present article provides a comparative analysis of operational distributedsimulation models based on the Time Warp algorithm. An operational model allowing for reduction of the simulation costs has been proposed based on an experimental evaluation.
暂无评论