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Exploring Wireless Mesh Networks for Collaborative Augmented Reality Environments

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Exploring Wireless Mesh Networks for Collaborative Augmented Reality Environments

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... At this point, the Sfoglina asks the player ents, performing some few circular movements with the of the board. If the user correctly performs this action, as techniques or similar schemes789101112131415161718192021, applying gesture recognition in a cultural/exhibition context has required the devise of innovative algorithms optimized for this specific field. We have described our gesture recognizer technique which, based on geometric considerations, can easily detect when a pre-defined gesture has been completed. ...
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KE: In Communications of the ACM, Vol 45 No 1 January, 2002 - Copyright (C) 2001 ACM Please visit http://www.tinmith.net for more information The aim of the ARQuake project was to construct a first-person-perspective game with the following attributes: . The game is played in the physical world, with the user able to freely move about the world. . The view is determined solely by the orientation and position of the user&apos;s head. . The game is experienced as augmented reality using a transparent HMD. . The game is controlled using easy to understand real-life props and metaphors. We wanted to build a system that allowed the user to play the game in a natural way. The user can see the game monsters at their virtual locations, and use real-life props such as a plastic gun with simulated recoil to shoot at the monsters. Our experience with test subjects has shown they find the game very natural, since the haptic feedback gun operates in a way people are us
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The relatively new field of artificial life attempts to study and understand biological life by synthesizing artificial life forms. To paraphrase Chris Langton, the founder of the field, the goal of artificial life is to “model life as it could be so as to understand life as we know it.” Artificial life is a very broad discipline which spans such diverse topics as artificial evolution, artificial ecosystems, artificial morphogenesis, molecular evolution, and many more. Langton offers a nice overview of the different research questions studied by the discipline [6]. Artificial life shares with artificial intelligence (AI) its interest in synthesizing adaptive autonomous agents. Autonomous agents are computational systems that inhabit some complex, dynamic environment, sense and act autonomously in this environment, and by doing so realize a set of goals or tasks for which they are designed.
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The wireless mesh network has been an emerging technology in recent years. Because the transmission medium used in networking backhaul APs is radio, the wireless mesh network is not only easy and cost effective in deployment, but also has good scalability in coverage area and capacity. The IEEE 802.11 MAC protocol has been adopted as the de-facto medium access control. In this paper, we assess the fitness of the IEEE 802.11 over wireless mesh networks. We focus on the question: Does the backhaul networking of a wireless mesh network have the capability to support multimedia transport? The backhaul must guarantee the throughput and the latency. Furthermore, the QoS guarantee is required for multimedia applications. We contend that it is really necessary to consider what the key is to be changed in the IEEE 802.11 so that it can adapt the IEEE 802.11 MAC protocol to wireless mesh networks. Through the study of existing solutions, we analyze the previous work and sketch the contours of the directions to achieve our goal in this article.
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We investigate the interaction between TCP and MAC layer in a wireless multi-hop network. Using simulation, we provide new insight into two critical problems of TCP over wireless multi-hop. The first is the conflict between TCP data packets and TCP ACKs, which causes performance to degrade for window sizes greater than 1 packet. The second is the interaction between TCP and MAC layer backoff timers which causes severe unfairness and capture conditions. We show that these effects are particularly pronounced in two families of MAC protocols that have been extensively used in ad-hoc network simulation and implementations, namely CSMA and FAMA (a descendent of MACA). We then demonstrate that these problems are in part overcome by using MACAW, a MAC layer protocol which extends MACA by adding link level ACKs and a less aggressive backoff policy. We argue that link level protection, backoff policy and selective queue scheduling are critical elements for efficient and fair operation of ad-hoc networks under TCP. These conclusions are supported by extensive simulation and measurement experiments
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With the growth in interactive network games comes an increased importance in a better understanding of the eects of latency on user performance. While previous work has studied the tolerance game players have for high latencies and has studied the eects of latency on user performance in real-time strategy games, to the best of our knowledge, there has been no systematic study of the eects of loss and latency on user performance. In this paper we study user performance for Unreal Tournament 2003 (UT2003), a popular FPS game, under varying amounts of latency and packet loss. First, we deduced typical real world values of packet loss and latency experienced on the Internet today by monitoring operational UT2003 game servers. We used these realistic values of loss and latency in a controlled networked environment that emulated various conditions of loss and latency, allowing us to test UT2003 at the network, application and user levels. We designed player actions down into the fundamental FPS interaction components of movement and shooting, and conducted numerous user studies under controlled network conditions. We nd that levels of packet loss and latency typical for most UT2003 Internet server, while unpleasant, will not drastically impact player performance. Since most FPS games typically consist of the similar generic player actions to those that we tested, we believe that these results may have broader implications.
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This paper surveys the current state-of-the-art in Augmented Reality. It describes work performed at many different sites and explains the issues and problems encountered when building Augmented Reality systems. It summarizes the tradeoffs and approaches taken so far to overcome these problems and speculates on future directions that deserve exploration. This paper does not present new research results. The contribution comes from consolidating existing information from many sources and publishing an extensive bibliography of papers in this field. While several other introductory papers have been written on this subject [Barfield95] [Bowskill95] [Caudell94] [Drascic93b] [Feiner94a] [Feiner94b] [Milgram94b] [Rolland94], this survey is more comprehensive and up-to-date. For anyone interested in starting research in this area, this survey should provide a good starting point. Section 1 describes what Augmented Reality is and the motivations for developing this technology. Four classes of potential applications that have been explored are described in Section 2. Then Section 3 discusses the issues involved in building an Augmented Reality system. Currently, two of the biggest problems are in registration and sensing, so those are the subjects of Sections 4 and 5. Finally, Section 6 describes some areas that require further work and research. 1.2 Definition
Mixed Reality Applications in Urban Environments
  • J Bulman
  • B Crabtree
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J. Bulman, B. Crabtree, A. Gower, A. Oldroyd, M. Lawson, J. Sutton, "Mixed Reality Applications in Urban Environments", BT Technology Journal, vol. 22, no. 3, Jul 2004, pp. 84-94.
Human Pacman: A Sensing-Based Mobile Entertainment System with Ubiquitous Computing and Tangible Interaction
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A. D. Cheok, S. W. Fong, K. H. Goh, X. Yang, W. Liu, F. Farzbiz, "Human Pacman: A Sensing-Based Mobile Entertainment System with Ubiquitous Computing and Tangible Interaction", in Proc. of ACM NETGAMES 2003, Redwood City, CA, USA, 2003.
802.11-2007, IEEE Standard for Information technology-Telecommunications and information exchange between systems-Local and metropolitan area networks-Specific requirements -Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications
IEEE, "802.11-2007, IEEE Standard for Information technology-Telecommunications and information exchange between systems-Local and metropolitan area networks-Specific requirements -Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications", Jun 2007.
Multi-protocol and Multi-platform Traffic Generation and Measurement
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A. Botta, A. Dainotti, A. Pescapè, "Multi-protocol and Multi-platform Traffic Generation and Measurement", INFOCOM 2007 DEMO Session, Anchorage, AK, USA, May 2007.
Performance Preorder: Ordering Processes with Respect to Speed
  • F Corradini
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F. Corradini, R. Gorrieri, M. Roccetti, "Performance Preorder: Ordering Processes with Respect to Speed", in Proc. of Mathematical Foundations of Computer Science, LNCS 969, Springer Berlin, 1995, pp. 444-453.