78,183 research outputs found

    Exploiting P2P in the Creation of Game Worlds

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    Peer-to-peer networks are a promising platform for supporting entirely decentralized, distributed multi-user gaming; however, multi-player games typically require highly predictable performance from the underlying network. This is at odds with the inherently unreliable nature of peer-to-peer environments. Existing approaches to providing peer-to-peer support for multi-player gaming focus on compensating for the unpredictability of the underlying network. We propose that rather than trying to compensate for these factors, they can be exploited together with information about the peer-to-peer network in order to address the problem of maintaining a novel gaming experience in the absence of a central authority. In order to explore our proposition, we model the measurable properties of P2P networks within a distributed multi-player game – NetWorld. We do this in such a way that the heterogeneous and unpredictable nature of the peer-to-peer environment becomes a positive part of the player’s experience

    Bounding inconsistency using a novel threshold metric for dead reckoning update packet generation

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    Human-to-human interaction across distributed applications requires that sufficient consistency be maintained among participants in the face of network characteristics such as latency and limited bandwidth. The level of inconsistency arising from the network is proportional to the network delay, and thus a function of bandwidth consumption. Distributed simulation has often used a bandwidth reduction technique known as dead reckoning that combines approximation and estimation in the communication of entity movement to reduce network traffic, and thus improve consistency. However, unless carefully tuned to application and network characteristics, such an approach can introduce more inconsistency than it avoids. The key tuning metric is the distance threshold. This paper questions the suitability of the standard distance threshold as a metric for use in the dead reckoning scheme. Using a model relating entity path curvature and inconsistency, a major performance related limitation of the distance threshold technique is highlighted. We then propose an alternative time—space threshold criterion. The time—space threshold is demonstrated, through simulation, to perform better for low curvature movement. However, it too has a limitation. Based on this, we further propose a novel hybrid scheme. Through simulation and live trials, this scheme is shown to perform well across a range of curvature values, and places bounds on both the spatial and absolute inconsistency arising from dead reckoning

    A collaborative platform for integrating and optimising Computational Fluid Dynamics analysis requests

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    A Virtual Integration Platform (VIP) is described which provides support for the integration of Computer-Aided Design (CAD) and Computational Fluid Dynamics (CFD) analysis tools into an environment that supports the use of these tools in a distributed collaborative manner. The VIP has evolved through previous EU research conducted within the VRShips-ROPAX 2000 (VRShips) project and the current version discussed here was developed predominantly within the VIRTUE project but also within the SAFEDOR project. The VIP is described with respect to the support it provides to designers and analysts in coordinating and optimising CFD analysis requests. Two case studies are provided that illustrate the application of the VIP within HSVA: the use of a panel code for the evaluation of geometry variations in order to improve propeller efficiency; and, the use of a dedicated maritime RANS code (FreSCo) to improve the wake distribution for the VIRTUE tanker. A discussion is included detailing the background, application and results from the use of the VIP within these two case studies as well as how the platform was of benefit during the development and a consideration of how it can benefit HSVA in the future

    A Taxonomy of Data Grids for Distributed Data Sharing, Management and Processing

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    Data Grids have been adopted as the platform for scientific communities that need to share, access, transport, process and manage large data collections distributed worldwide. They combine high-end computing technologies with high-performance networking and wide-area storage management techniques. In this paper, we discuss the key concepts behind Data Grids and compare them with other data sharing and distribution paradigms such as content delivery networks, peer-to-peer networks and distributed databases. We then provide comprehensive taxonomies that cover various aspects of architecture, data transportation, data replication and resource allocation and scheduling. Finally, we map the proposed taxonomy to various Data Grid systems not only to validate the taxonomy but also to identify areas for future exploration. Through this taxonomy, we aim to categorise existing systems to better understand their goals and their methodology. This would help evaluate their applicability for solving similar problems. This taxonomy also provides a "gap analysis" of this area through which researchers can potentially identify new issues for investigation. Finally, we hope that the proposed taxonomy and mapping also helps to provide an easy way for new practitioners to understand this complex area of research.Comment: 46 pages, 16 figures, Technical Repor
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