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The following topics are dealt with: distributed simulation; real time applications; disaster management; performance and interest management; virtual reality; interoperability; composibility; and high level architecture.
To individuals evacuating, many multi-exit environments do not allow visibility of all the exits due to line-of-sight constraint. In addition, the environment can be dark or smoky, not allowing visibility to even a single exit. In such a situation, given that each individual in the crowd is accompanied with a helping device globally connected with a central server, a 'directional guidance' towards...
The recent emergence of dramatically large computational power, spanning desktops with multi-core processors and multiple graphics cards to supercomputers with 105 processor cores, has suddenly resulted in simulation-based solutions trailing behind in the ability to fully tap the new computational capacity. Here, we motivate the need for switching the parallel simulation research to a higher gear...
Computer simulation is an important factor in today's disaster prevention procedures. Simulation codes assess the evolution and impact of various physical phenomena in domains such as nuclear and environmental sciences, and ultimately help saving lives. However, new and more computationally demanding models, and new regulations for personnel training have increased the demand for computational power...
To support the evacuation process of crowds from emergency situations, we have developed a wearable device, LifeBelt, for vibro tactile guidance of individuals in panic towards exits. Since visual and auditory perception is overwhelmed in situations of panic, exit sign and loudspeaker based evacuation often appears ineffective. LifeBelt as a coordinated navigation device builds on a subtle directional...
In parallel discrete event simulation techniques, the simulation model is partitioned into objects, concurrently executing events on different CPUs and/or multiple CPU-Cores.In such a context, run-time supports for logical time synchronization across the different simulation objects play a central role in determining the effectiveness of the specific parallel simulation environment. In this paper...
In this paper, we present and evaluate a system for performing logical-time synchronised Range Queries over data in the context of parallel and distributed simulations of Multi-Agent Systems (MAS). MAS are often extremely complex and simulation is commonly used to understand their behaviour or investigate the implications of alternative agent architectures. Range Queries are widely used in various...
Consistency maintenance in distributed interactive applications (DIAs) is subjected to network characteristics such as limited bandwidth and latency. Predictive contract mechanisms are techniques that compensate for the effect of network latency by extrapolating future entity states from historical records. These approaches trade inconsistency within human perceptual limits for reduced network traffic...
Interest management is essential for real-time large-scale distributed virtual environments (DVEs) which seeks to filter irrelevant messages on the network. Many existing interest management schemes such as HLA DDM focus on providing precise message filtering mechanisms. However, this leads to a second problem: the computational overhead of the interest matching process. If the CPU cost of interest...
Predicting latency between nodes on the Internet can have a significant impact on the performance of many services that use latency distances among nodes as a decision making input. Coordinate-based approaches are among the family of latency prediction techniques where latency between each pair of nodes is modeled as the virtual distance among those nodes over a virtual system. This article proposes...
Virtual environments (VEs) have recently gained a lot of attention from the computing, graphics, business and social communities due to a remarkable increase in their popularity. These communities are working together to make these environments more sociable and interesting while introducing novel applications. A number of technical infrastructures are currently hosting these environments, however,...
DEVS Modeling and Simulation (M&S) has multiple implementations with several computer languages such as Java, C# or C++. Therefore emerges the need of a distributed platform to provide interoperability mechanics for simulation and encourage reusability of legacy simulations and integration of diversified DEVS models. In this paper, we apply a recently proposed interoperability standard for DEVS...
The increasing use of model-based tools enables further use of formal verification techniques in the context of distributed real-time systems. To avoid state explosion, it is necessary to construct verification models that focus on the aspects under consideration.In this paper, we discuss how we construct a verification model for timing analysis in distributed real-time systems.We (1) give observations...
This paper reports about a research project-HLA ACTOR REPAST- aimed to distributing RePast models thus potentially corresponding to the computational demands of large and reconfigurable multi-agent systems (MASs). Novel in HLA ACTOR REPAST is an exploitation of a lean actor infrastructure implemented in Java. Actors bring to RePast agents such features as migration, location-transparent naming,efficient...
Base object model (BOM) is a component-based standard designed to support reusability and composability. Reusability helps in reducing time and cost of the development of a simulation process. Composing predefined components such as BOMs is a well known approach to achieve reusability. However, there is a need for a matching mechanism to identify whether a set of components are composable or not....
This paper presents an architecture to support the modeling of different high level architecture (HLA) compliant emergency management training simulations. Different ontologies are created to support complex simulation instantiation. Simulations can be accessed through any device that can run an X3D browser. A context database is created, which provides real life events, collected via wireless sensor...
Scalability is very important for parallel and distributed simulations. Several techniques have been proposed to develop scalable synchronization strategies, communication services or fundamental algorithms, while little has been seen to deal with the modeling stage of the application. Learning from the HPC (High Performance Computing) lesson, it is clear that the time spent in developing a simulation...
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