129,742 research outputs found

    О новом роде верхнепалеозойских растений Brovuchkia Parfenova gen. nov. из Кемеровского района Кузбасса

    Get PDF
    Multimedia information systems have been developed into service-ware. With the paradigms of web services, service oriented architectures (SOA), and Web 2.0 widgets, multimedia has become truly ubiquitous. However, interoperability, scalability, reliability and security are arising challenges at mobile multimedia service development. This paper focuses on the analysis, design, development and evaluation of a middleware that allows access from mobile devices to a bundle of multimedia services. The services are based on the international multimedia metadata description standard MPEG-7. The implementation is based on new generation of service-oriented application servers called Lightweight Application Server (LAS). Mobile web services refer to the fact that mobile servers host web services. A prototype was developed as a proof of concept, showing how to access MPEG-7 based multimedia services from a Mobile Host and the analysis results of providing MPEG-7 based multimedia services in the form of web services from the Mobile Host to other mobile devices. An alternative solution is to apply enterprise service bus technology as the middleware. The performance evaluation results of both approaches show the reliable accessibility of MPEG-7 based multimedia services via the enterprise service bus solution

    Multicast broadcast services support in OFDMA-based WiMAX systems [Advances in mobile multimedia]

    Get PDF
    Multimedia stream service provided by broadband wireless networks has emerged as an important technology and has attracted much attention. An all-IP network architecture with reliable high-throughput air interface makes orthogonal frequency division multiplexing access (OFDMA)-based mobile worldwide interoperability for microwave access (mobile WiMAX) a viable technology for wireless multimedia services, such as voice over IP (VoIP), mobile TV, and so on. One of the main features in a WiMAX MAC layer is that it can provide'differentiated services among different traffic categories with individual QoS requirements. In this article, we first give an overview of the key aspects of WiMAX and describe multimedia broadcast multicast service (MBMS) architecture of the 3GPP. Then, we propose a multicast and broadcast service (MBS) architecture for WiMAX that is based on MBMS. Moreover, we enhance the MBS architecture for mobile WiMAX to overcome the shortcoming of limited video broadcast performance over the baseline MBS model. We also give examples to demonstrate that the proposed architecture can support better mobility and offer higher power efficiency

    CGMP: cloud-assisted green multimedia processing

    Get PDF
    With continued advancements of mobile computing and communications, emerging novel multimedia services and applications have attracted lots of attention and been developed for mobile users, such as mobile social network, mobile cloud medical treatment, mobile cloud game. However, because of limited resources on mobile terminals, it is of great challenge to improve the energy efficiency of multimedia services. In this paper, we propose a cloud-assisted green multimedia processing architecture (CGMP) based on mobile cloud computing. Specifically, the tasks of multimedia processing with energy-extensive consumption can be offloaded to the cloud, and the face recognition algorithm with improved principal component analysis and nearest neighbor classifier is realized on CGMP based cloud platform. Experimental results show that the proposed scheme can effectively save the energy consumption of the equipment

    Rapid prototyping and fast user trial of multimedia broadcast and cellular services

    Get PDF
    This paper presents the results of fast user trial of multimedia services that are enabled when a mobile terminal has access to converged services over digital broadcast and mobile telecommunications networks. It first describes the motivations behind developing this system and describes the service scenarios that benefit most from it. It then provides an overview of the service components of the test case scenario. Finally, it presents the results of fast user trials on end users of the services that were developed. This work was conducted as part of the EU-funded CISMUNDUS project

    Harnessing mobile technology for classroom learning

    No full text
    Educational institutions are reluctant adopt mobile computing and Wireless technologies. This is because this technology remains relatively expensive compared to traditional computing technologies, mobile devices are inherently personal and can be difficult to use as a teaching tool to groups of learners, and Short Message Services and Multimedia Message Services (SMS/MMS) are expensive and limited in functional scope despite their popularity amongst young people. In this paper, we describe a component of a prototype learning environment named Quest where we propose anew way of harnessing mobile technology for learning that negates these drawbacks. In Quest we have demonstrated that the information gathering capabilities of mobile phones can be harnessed to aid learners research

    Context-Aware Adaptation of Mobile Multimedia Presentations

    Get PDF
    With increasing capabilities of mobile devices, the number of mobile multimedia services grows steadily. Usage of multimedia services and especially the presentation of multimedia content is more challenging in a mobile environment than on stationary devices due to the diversity of mobile devices and their parameters, the sparse resources of the air interface or the changing context. This position paper introduces an approach for context-aware adaptation of mobile multimedia presentations. For this, a middleware architecture is proposed that performs an automatic and distributed adaptation process: while the server provides a pre-processing of the content, the client completes the overall adaptation. To support this task, the Adaptation Rule Language (ARL) was developed which is introduced in this paper as well

    Quality assessment and usage behavior of a mobile voice-over-IP service

    Get PDF
    Voice-over-IP (VoIP) services offer users a cheap alternative to the traditional mobile operators to make voice calls. Due to the increased capabilities and connectivity of mobile devices, these VoIP services are becoming increasingly popular on the mobile platform. Understanding the user's usage behavior and quality assessment of the VoIP service plays a key role in optimizing the Quality of Experience (QoE) and making the service to succeed or to fail. By analyzing the usage and quality assessments of a commercial VoIP service, this paper identifies device characteristics, context parameters, and user aspects that influence the usage behavior and experience during VoIP calls. Whereas multimedia services are traditionally evaluated by monitoring usage and quality for a limited number of test subjects and during a limited evaluation period, this study analyzes the service usage and quality assessments of more than thousand users over a period of 120 days. This allows to analyze evolutions in the usage behavior and perceived quality over time, which has not been done up to now for a widely-used, mobile, multimedia service. The results show a significant evolution over time of the number of calls, the call duration, and the quality assessment. The time of the call, the used network, and handovers during the call showed to have a significant influence on the users' quality assessments
    corecore