51 research outputs found

    The state of peer-to-peer network simulators

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    Networking research often relies on simulation in order to test and evaluate new ideas. An important requirement of this process is that results must be reproducible so that other researchers can replicate, validate and extend existing work. We look at the landscape of simulators for research in peer-to-peer (P2P) networks by conducting a survey of a combined total of over 280 papers from before and after 2007 (the year of the last survey in this area), and comment on the large quantity of research using bespoke, closed-source simulators. We propose a set of criteria that P2P simulators should meet, and poll the P2P research community for their agreement. We aim to drive the community towards performing their experiments on simulators that allow for others to validate their results

    MediaSync: Handbook on Multimedia Synchronization

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    This book provides an approachable overview of the most recent advances in the fascinating field of media synchronization (mediasync), gathering contributions from the most representative and influential experts. Understanding the challenges of this field in the current multi-sensory, multi-device, and multi-protocol world is not an easy task. The book revisits the foundations of mediasync, including theoretical frameworks and models, highlights ongoing research efforts, like hybrid broadband broadcast (HBB) delivery and users' perception modeling (i.e., Quality of Experience or QoE), and paves the way for the future (e.g., towards the deployment of multi-sensory and ultra-realistic experiences). Although many advances around mediasync have been devised and deployed, this area of research is getting renewed attention to overcome remaining challenges in the next-generation (heterogeneous and ubiquitous) media ecosystem. Given the significant advances in this research area, its current relevance and the multiple disciplines it involves, the availability of a reference book on mediasync becomes necessary. This book fills the gap in this context. In particular, it addresses key aspects and reviews the most relevant contributions within the mediasync research space, from different perspectives. Mediasync: Handbook on Multimedia Synchronization is the perfect companion for scholars and practitioners that want to acquire strong knowledge about this research area, and also approach the challenges behind ensuring the best mediated experiences, by providing the adequate synchronization between the media elements that constitute these experiences

    VR-LAB: A Distributed Multi-User Environment for Educational Purposes and Presentations

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    In the last three years our research was focused on a new distributed multi-user environment. Finally, all components were integrated in a system called the VR-Lab, which will be described on the following pages. The VR-Lab provides Hard- and Software for a distributed presentation system. Elements which are often used in environments called Computer Supported Cooperative Work (CSCW). In contrast to other projects the VR-Lab integrates a distributed system in a common environment of a lecture room and does not generate a virtual conference room in a computer system. Thus, allowing inexperienced persons to use the VR-LAB and benefit from the multimedia tools in their common environment. To build the VR-LAB we developed a lot of hard- and software and integrated it into a lecture room to perform distributed presentations, conferences or teaching. Additionally other software components were developed to be connected to the VR-LAB, control its components, or distribute content between VR-LAB installations. Beside standard software for video and audio transmission, we developed and integrated a distributed 3D-VRML-Browser to present three dimensional content to a distributed audience. One of the interesting features of this browser is the object oriented distributed scene graph. By coupling a high-speed rendering system with a database we could distribute objects to other participants. So the semantic properties of any geometrical or control object can be kept and used by the remote participant. Because of the high compression achieved by the transport of objects instead of triangles a lot of bandwidth could be saved. Also each participant could select a display quality appropriate to its hardware.Diese Arbeit beschreibt ein integriertes Virtual-Reality System, das VR Lab. Das System besteht aus verschiedenen Hard- und Softwarekomponenten die eine verteiltevirtuelle Multi-User Umgebung darstellen die vor allem im Bereich verteilter Präsentationen verwendet werden kann. Im Gegensatz zu anderen Systemen dieser Art, die oft im Bereich des Computer Supported Cooperative Work (CSCW) eingesetzt werden dient unser System nicht dazu eine Präsentationsumgebung im Computer nachzubilden sondern eine reele Umgebung zu schaffen in der verteilte Präsentationen durchgeführt werden können. Dies soll vor allem ungeübten Personen die Arbeit mit verteilten Umgebungen erleichtern. Dazu wurden verschiedene Hard- und Softwarekomponenten entwickelt. Darunter der verteilte 3D Browser MRT-VR, der es ermöglicht 3D Daten an verschiedenen Stellen gleichzeitig zu visualisieren. MRT-VR zeichnet sich insbesondere dadurch aus, daß die 3D Objekte nicht als Polygondaten transportiert werden, sonderen als Objekte und so deren Objekteigenschaften beibehalten werden. Dies spart nicht nur sehr viel Bandbreite bei der Übertragung sondern ermöglicht auch Darstellungen in unterschiedlichen Qualitätsstufen auf den unterschiedlichen Zielrechnern der Teilnehmer. Ein weiterer Teil der Arbeit beschreibt die Entwicklung einer preiswerten imersiven 3D Umgebung um die 3D Daten in ansprechender Qualität zu visualisieren. Alle Komponenten wurden in einer gemeinsamen Umgebung, dem VR-Lab, integriert und mt Steuerungskomponenten versehen

    Panoramic Augmented Reality for Persistence of Information in Counterinsurgency Environments (PARPICE)

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    Modern Counter-Insurgency (COIN) and Irregular Warfare (IW) are increasingly complex. Contributing to this complexity is the need to develop and maintain a mental map of relevant environmental and historical factors and their interactions, generated from disparate sources of information that must be organized, processed and integrated. Compounding this challenge is the fact that mental pictures cannot easily be passed from one soldier to the next. This is a problem when the tactical situation dictates frequent changes in unit Areas of Operations (AOs), and particularly in cases where units rotate on a regular basis. When units hand over an AO, the incoming unit must quickly rebuild a mental picture and narrative of its operating environment. Because of this, historical organizational knowledge is lost that could otherwise increase combat effectiveness and reduce casualties. This thesis discusses a prototype architecture for a system that will enable a vehicle crew commander to spatially input, organize and view fused tactical information through placement of 3D interactive symbols directly into the real-life on-site scene from the vehicle perspective. A panoramic camera, dashboard monitor and head tracker give the commander a complete view of the vehicle surroundings for improved situational awareness, and a 360-degree LiDAR scanner supplies depth information for accurate annotation geo-location. This system is intended to generate greater situational understanding of the complex environment present in COIN operations, in order to allow greater performance and survivability of the vehicle crew. Such a system, if fielded, can create the ability to add numerous other capabilities to the combat vehicle crew.http://archive.org/details/panoramicaugment109455057JIEDDO; HQDA G-8 CAAUS Army (USA) authorApproved for public release; distribution is unlimited

    The Sensor Network Workbench: Towards Functional Specification, Verification and Deployment of Constrained Distributed Systems

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    As the commoditization of sensing, actuation and communication hardware increases, so does the potential for dynamically tasked sense and respond networked systems (i.e., Sensor Networks or SNs) to replace existing disjoint and inflexible special-purpose deployments (closed-circuit security video, anti-theft sensors, etc.). While various solutions have emerged to many individual SN-centric challenges (e.g., power management, communication protocols, role assignment), perhaps the largest remaining obstacle to widespread SN deployment is that those who wish to deploy, utilize, and maintain a programmable Sensor Network lack the programming and systems expertise to do so. The contributions of this thesis centers on the design, development and deployment of the SN Workbench (snBench). snBench embodies an accessible, modular programming platform coupled with a flexible and extensible run-time system that, together, support the entire life-cycle of distributed sensory services. As it is impossible to find a one-size-fits-all programming interface, this work advocates the use of tiered layers of abstraction that enable a variety of high-level, domain specific languages to be compiled to a common (thin-waist) tasking language; this common tasking language is statically verified and can be subsequently re-translated, if needed, for execution on a wide variety of hardware platforms. snBench provides: (1) a common sensory tasking language (Instruction Set Architecture) powerful enough to express complex SN services, yet simple enough to be executed by highly constrained resources with soft, real-time constraints, (2) a prototype high-level language (and corresponding compiler) to illustrate the utility of the common tasking language and the tiered programming approach in this domain, (3) an execution environment and a run-time support infrastructure that abstract a collection of heterogeneous resources into a single virtual Sensor Network, tasked via this common tasking language, and (4) novel formal methods (i.e., static analysis techniques) that verify safety properties and infer implicit resource constraints to facilitate resource allocation for new services. This thesis presents these components in detail, as well as two specific case-studies: the use of snBench to integrate physical and wireless network security, and the use of snBench as the foundation for semester-long student projects in a graduate-level Software Engineering course

    Transforming the museum-community nexus with technology : a virtual museum infrastructure for participatory engagement and management

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    Museums play an important role in society as the custodians of heritage, and advances in technology have brought about opportunities for curating, preserving and disseminating heritage through virtual museums. However, this is not matched by an understanding of how these technologies can support these functions, especially given the varying levels of resources that museums have at their disposal. To address this problem, a hybrid methodology which combines underpinning theory and practice has been adopted. Initial investigation of the problem takes place through a contextualisation of museology and heritage studies, followed by exploratory case studies that yield design objectives for a Virtual Museum Infrastructure (VMI). A design of the VMI is proposed based on these objectives, and the VMI is instantiated, deployed and evaluated in real-world scenarios using a combination of quantitative and qualitative techniques. The findings of this investigation demonstrate that the use of technology provides new opportunities for engagement with heritage, as experts and community members alike can create, curate and preserve content, which can then be disseminated in engaging ways using immersive, yet affordable technologies. This work therefore demonstrates how technology can be used to: (1) support museums in the creation, curation, preservation and dissemination of heritage, through a VMI that provides support for all the stages of the media life cycle, (2) facilitate active use, so that content that is created once can be reused on multiple platforms (for example on the web, on mobile apps and in on-site installations), and (3) encourage connectivity by linking up local museums using a location-aware interface and facilitates the consumption content using digital literacies available to the public. The aforementioned points, coupled with the system instantiations that demonstrate them, represent the contributions of this thesis
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