56,756 research outputs found

    An Integrated Network Architecture for a High Speed Distributed Multimedia System.

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    Computer communication demands for higher bandwidth and smaller delays are increasing rapidly as the march into the twenty-first century gains momentum. These demands are generated by visualization applications which model complex real time phenomena in visual form, electronic document imaging and manipulation, concurrent engineering, on-line databases and multimedia applications which integrate audio, video and data. The convergence of the computer and video worlds is leading to the emergence of a distributed multimedia environment. This research investigates an integrated approach in the design of a high speed computer-video local area network for a distributed multimedia environment. The initial step in providing multimedia services over computer networks is to ensure bandwidth availability for these services. The bandwidth needs based on traffic generated in a distributed multimedia environment is computationally characterized by a model. This model is applied to the real-time problem of designing a backbone for a distributed multimedia environment at the NASA Classroom of the Future Program. The network incorporates legacy LANs and the latest high speed switching technologies. Performance studies have been conducted with different network topologies for various multimedia application scenarios to establish benchmarks for the operation of the network. In these performance studies it has been observed that network topologies play an important role in ensuring that sufficient bandwidth is available for multimedia traffic. After the implementation of the network and the performance studies, it was found that for true quality of service guarantees, some modifications will have to be made in the multimedia operating systems used in client workstations. These modifications would gather knowledge of the channel between source and destination and reserve resources for multimedia communication based on specified requirements. A scheme for reserving resources in a network consisting legacy LAN and ATM is presented to guarantee quality of service for multimedia applications

    Multicriteria decision making for enhanced perception-based multimedia communication

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    This paper proposes an approach that integrates technical concerns with user perceptual considerations for intelligent decision making in the construction of tailor-made multimedia communication protocols. Thus, the proposed approach, based on multicriteria decision making (MDM), incorporates not only classical networking considerations, but, indeed, user preferences as well. Furthermore, in keeping with the task-dependent nature consistently identified in multimedia scenarios, the suggested communication protocols also take into account the type of multimedia application that they are transporting. Lastly, this approach also opens the possibility for such protocols to dynamically adapt based on a changing operating environment and user's preferences

    Analysis of a Multimedia Stream using Stochastic Process Algebra

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    It is now well recognised that the next generation of distributed systems will be distributed multimedia systems. Central to multimedia systems is quality of service, which defines the non-functional requirements on the system. In this paper we investigate how stochastic process algebra can be used in order to determine the quality of service properties of distributed multimedia systems. We use a simple multimedia stream as our basic example. We describe it in the Stochastic Process Algebra PEPA and then we analyse whether the stream satisfies a set of quality of service parameters: throughput, end-to-end latency, jitter and error rates

    Semantic multimedia remote display for mobile thin clients

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    Current remote display technologies for mobile thin clients convert practically all types of graphical content into sequences of images rendered by the client. Consequently, important information concerning the content semantics is lost. The present paper goes beyond this bottleneck by developing a semantic multimedia remote display. The principle consists of representing the graphical content as a real-time interactive multimedia scene graph. The underlying architecture features novel components for scene-graph creation and management, as well as for user interactivity handling. The experimental setup considers the Linux X windows system and BiFS/LASeR multimedia scene technologies on the server and client sides, respectively. The implemented solution was benchmarked against currently deployed solutions (VNC and Microsoft-RDP), by considering text editing and WWW browsing applications. The quantitative assessments demonstrate: (1) visual quality expressed by seven objective metrics, e.g., PSNR values between 30 and 42 dB or SSIM values larger than 0.9999; (2) downlink bandwidth gain factors ranging from 2 to 60; (3) real-time user event management expressed by network round-trip time reduction by factors of 4-6 and by uplink bandwidth gain factors from 3 to 10; (4) feasible CPU activity, larger than in the RDP case but reduced by a factor of 1.5 with respect to the VNC-HEXTILE

    The impact of cognitive styles on perceptual distributed multimedia quality

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    This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2003 John Wiley & Sons, Inc.Multimedia technology has been widely used in web-based instruction, but previous studies have indicated that individual differences, especially cognitive styles, have significant effects on users’ preferences with respect to presentation of multimedia content. However, such research has thus far neglected to examine the effect of cognitive styles on users’ subjective perceptions of multimedia quality. This study aims to examine the relationships among users’ cognitive styles, the multimedia Quality of Service (QoS) delivered by the underlying network, and Quality of Perception (QoP), which encompasses user levels of enjoyment and understanding of the informational content provided by multimedia material. Accordingly, 132 users took part in an experiment in which they were shown multimedia video clips presented with different values of two QoS parameters (frame rate and colour depth). Results show that, whilst the two QoS parameters do not impact user QoP, multimedia content and dynamism levels significantly influence the user understanding and enjoyment component of QoP

    Faktor-faktor adaptasi logistik terbalik di sektor pembuatan

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    Dalam dunia yang mempunyai sumber yang terhad, proses pemulihan yang digunakan untuk bahan atau produk adalah kunci untuk menyokong populasi penduduk dalam meningkatkan penggunaan bahan. Pengurangan bahan buangan menjadi kebimbangan kepada industri negara yang berkonsepkan kitaran bahan kerana bahan buangan tersebut merupakan salah satu sumber yang menjana ekonomi industri tersebut. Proses terbalik melibatkan kos yang besar berbanding keuntungan. Perubahan dalam undang-undang untuk melindungi alam sekitar telah memberi kesan kepada ekonomi dan perkhidmatan. Kini, semakin banyak syarikat yang menggunakan proses aliran terbalik untuk pergerakan barangan dalam sistem logistik mereka. Industri pembuatan merupakan industri utama dalam penggunaan aktiviti logistik terbalik. Sistem logistik terbalik merupakan aktiviti yang membentuk proses yang berterusan untuk penggunaan semula produk sama ada digunakan semula ataupun untuk pelupusan. Pembuatan semula ditakrifkan sebagai salah satu kaedah pemulihan yang digunakan untuk produk yang rosak atau bahagian-bahagian yang boleh diperolehi semula dalam keadaan kualiti yang sama dengan produk baharu dan boleh dimasukkan ke dalam produk baharu dan akan dijual semula dalam pasaran sama dengan bahagian atau produk baharu. Aktiviti logistik terbalik sering dilaksanakan oleh pengeluar asal kerana bahan yang digunakan semula diperlukan untuk pengetahuan dalam pengeluaran tertentu. Eltayeb dan Zailani (2010) menyatakan kebanyakan pengeluar di Malaysia tidak berminat untuk menggunakan semula barangan kitar semula atau pelupusan disebabkan oleh perbelanjaan tambahan untuk mengendalikan aktiviti yang berkaitan dengan logistik terbalik

    Towards a Framework for Developing Mobile Agents for Managing Distributed Information Resources

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    Distributed information management tools allow users to author, disseminate, discover and manage information within large-scale networked environments, such as the Internet. Agent technology provides the flexibility and scalability necessary to develop such distributed information management applications. We present a layered organisation that is shared by the specific applications that we build. Within this organisation we describe an architecture where mobile agents can move across distributed environments, integrate with local resources and other mobile agents, and communicate their results back to the user

    Holographic and 3D teleconferencing and visualization: implications for terabit networked applications

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    Demo : distributed video coding applications in wireless multimedia sensor networks

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    Novel distributed video coding (DVC) architectures developed by the IBBT DVC group realize state-of-the-art video coding efficiency under stringent energy restrictions, while supporting error-resilience and scalability. Therefore, these architectures are particularly attractive for application scenarios involving low-complexity energy-constrained wireless visual sensors. This demo presents the scenarios, which are considered to be the most promising areas of integration for IBBT's DVC systems, considering feasibility and commercial applicability
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