Several real-timeapplications require communication services with guaranteed timeliness and fault-tolerance at acceptable levels of overhead. Different applications/end users may need different levels of fault-tolera...
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Several real-timeapplications require communication services with guaranteed timeliness and fault-tolerance at acceptable levels of overhead. Different applications/end users may need different levels of fault-tolerance and differ in how much they are willing to pay for the service they get. A control scheme which is used to set up and tear down paths, should not only be fast and efficient, must also be scalable, and should try to minimize the number of blocked connections; while satisfying the requested level of fault-tolerance. In this work we propose a distributed control scheme based on preferred link approach for establishing reliability-constrained least-cost paths, by choosing the reliability of the path to denote the level of fault-tolerance required by the connection request. The scheme is flexible in that a variety of heuristics can be employed to order the neighboring links of any given node. Four heuristics are proposed and their performance is studied through extensive simulation experiments. The proposed heuristics do not require maintenance of any global state information. The simulation results suggest that our heuristics are attractive enough in terms of average call acceptance rate, average path cost, average routing distance, and average connection setup time. Furthermore, if the network service provider feels that he/she can earn more revenue by admitting more number of calls with reliability requirements, he/she can do so by manipulating the parameters of our scheme, such as the maximum number of preferred links used at each node.
We attempt to quantify mental excitement in a VR environment. Specifically, the study tracked the amount of water evaporating from the palm over time as the subject maneuvered a flight simulator application, engaging ...
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We attempt to quantify mental excitement in a VR environment. Specifically, the study tracked the amount of water evaporating from the palm over time as the subject maneuvered a flight simulator application, engaging in simulations of difficult or dangerous flights. The consumer software application Fight Simulator 98 (VR) was used as VR content on a PC running Windows 98. In this simulation, the flight begins at Tokyo Haneda Airport, where a jumbo jet takes off toward the south, rising in altitude. The subject is free to select from several stimulating or dangerous flights in advance, and is free to maneuver the plane as its pilot. This thrilling flight is not entirely realistic, although the plane takes off and lands in a specified airport with a real-world counterpart. The volume of water measured from the skin of all five subjects increased synchronously with the thrilling flight, though with some individual variations in volume. This phenomena were considered to represent episodes of mental sweating. Thrilling flights in a flight simulator /spl rArr/ fear of crashing /spl rArr/ neural arousal (rapid responses of visual and motor fields) /spl rArr/ excitation of hypothalamus /spl rArr/ (increased) blood flow of capillary arteries of the skin /spl rArr/ (increased) volume of water from the skin. Current game systems are unable to sense player excitement. interactive VR systems or game systems with programs capable of detecting player arousal have many potential applications.
The proceedings contain 15 papers. The topics discussed include: the convergence of multicast communication and active networking: opportunities for restructuring networked applications;distributed interaction in virt...
ISBN:
(纸本)0769504590
The proceedings contain 15 papers. The topics discussed include: the convergence of multicast communication and active networking: opportunities for restructuring networked applications;distributed interaction in virtual spaces;collaborative virtual environment standards: a performance evaluation;analysis of dead reckoning procedures by using hybrid automata;near real-timesimulation of particle systems;object and ownership management in air traffic control simulations;distributedinteractive learning environment;reliable multicast network transport for distributed virtual simulation;an approach for stream transmission over HIA-RTI in distributed virtual environments;performance analysis of packet bundling techniques in DIS;resolving concurrent interactions;HLA support in a discrete event simulation language;ruminations on the implications of multi-resolution modeling on DIS/HLA;design and implementation of a distributedinteractivesimulation security architecture;simulation of multimedia systems based on actors and QoS-synchronizers;and agent-aided collaborative virtual environments over HLA/RTI.
This paper extends our previous work on formalizing event orderings using partial order set and its application in space analysis in distributedsimulation. We focus on the time an space trade-off in exploiting event ...
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ISBN:
(纸本)0769518532
This paper extends our previous work on formalizing event orderings using partial order set and its application in space analysis in distributedsimulation. We focus on the time an space trade-off in exploiting event parallelism. Event parallelism is divided into inherent (problem) parallelism, event ordering parallelism and effective event parallelism. Firstly, we analyze the performance cost of varying event ordering parallelism on memory requirement in open and closed systems. Secondly, we study the effects of interconnection topology Of a physical system on exploitable event ordering parallelism. Measurements were obtained from a time-space analyzer that we have developed.
With distributedsimulation, existing simulations, even from different disciplines, can be reused or made to interoperate. The efficiency of this technique is however not firmly established and it depends on the abili...
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ISBN:
(纸本)0769518532
With distributedsimulation, existing simulations, even from different disciplines, can be reused or made to interoperate. The efficiency of this technique is however not firmly established and it depends on the ability to satisfy a number of requirements, especially concerning simulation performance. The performance depends to a large extent on the structure and scaling of architectural components of the simulation execution platform. In this paper, we present an approach to address this problem: the design of models to capture the main characteristics of distributedsimulations, run-time infrastructures and network architectures, and the development of a tool to predict performances. This tool, which is a simulator of HLA simulations is written by using HLA and is evaluated on three test applications.
Running a large-scale distributedsimulation may need a large amount of computing resources at geographically different locations. These resources may be from different organizations. The simulation may run for a long...
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ISBN:
(纸本)0769518532
Running a large-scale distributedsimulation may need a large amount of computing resources at geographically different locations. These resources may be from different organizations. The simulation may run for a long period of time and the availability and the amount of computing resources available may change during the course of the simulation execution. Therefore, coordinating and managing the resources for distributedsimulation to complete the simulation efficiently and effectively is a, critical issue. This paper describes a load management system for HLA-based distributedsimulation. The system is constructed on top of a Grid Computing environment supported by Globus. The overall structure of the system is presented in the paper and how the system saves and restores a federate is also discussed in detail.
The High-Level Architecture (HLA) provides a common architecture for distributed modeling and simulation. In its original form, the HLA allows a number of simulations to be joined together into a federation using a si...
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ISBN:
(纸本)0769518532
The High-Level Architecture (HLA) provides a common architecture for distributed modeling and simulation. In its original form, the HLA allows a number of simulations to be joined together into a federation using a single run time infrastructure. Recently there has been an interest in joining multiple such federations together using a mediating unit, called an HLA "bridge." This paper presents the results of an in-depth study of the feasibility of an HLA bridge in the context of the current HLA interface specification. Problems and solutions are discussed and illustrated using particular HLA services.
simulation has always been a valuable tool for experimentation and validation of models, architectures and mechanisms in the, field of networking. In the case of the DiffServ framework, simulation is even more valuabl...
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ISBN:
(纸本)0769518532
simulation has always been a valuable tool for experimentation and validation of models, architectures and mechanisms in the, field of networking. In the case of the DiffServ framework, simulation is even more valuable, due to the fact that an analytical approach of mechanisms and services is infeasible because of the aggregation and multiplexing of flows. In this work, we have extended the functionality of a widely used simulation environment towards the direction of realistic traffic generation and a series of mechanisms defined by the DiffServ architecture. The modules created are being presented and a case study of a simulation scenario that exploits the functionality provided by them is described.
The Generic Runtime Infrastructure for distributedsimulation (GRIDS) has been developed to investigate modularity issues in distributedsimulation. It could be argued that although the HLA RTI is a widespread solutio...
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ISBN:
(纸本)0769518532
The Generic Runtime Infrastructure for distributedsimulation (GRIDS) has been developed to investigate modularity issues in distributedsimulation. It could be argued that although the HLA RTI is a widespread solution to distributedsimulation, it cannot include all possible services. This paper investigates an approach to extending the distributedsimulation services available in the HLA RTI. One example of this is bridging support for HLA/DIS legacy integration. This paper therefore presents GRIDS, how GRIDS can be used to provide modular service support for the HLA RTI, and a case study on legacy integration to demonstrate our approach.
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