Dissertations / Theses on the topic 'Multimedia systems'
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Al, Osman Hussein. "Ubiquitous Biofeedback Multimedia Systems." Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31229.
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Human wellbeing, in a large component, relies on the harmony between the body and the mind. Unfortunately, we often miss or ignore important signals from our bodies, and sometimes this can negatively impact our health. Therefore, the use of intelligent systems that grasp such signals and convey them in an intuitive manner to our minds can result in great health benefits. In this Thesis, we introduce a family of multimedia technologies and techniques aimed at realizing such systems. We call them: Ubiquitous Biofeedback Multimedia Systems. Although the notion of clinical biofeedback has been around for years, we introduce the concept of Ubiquitous Biofeedback where the biofeedback operation is given geographical and temporal ubiquity attributes. A Ubiquitous Biofeedback reference model is introduced in the Thesis to provide an abstract structural representation of the various components at play in a typical non-clinical biofeedback environment. Two systems that implement the reference model’s components are presented. These systems implement the concept of Ubiquitous Biofeedback through the introduction of innovative stress management methods. An important component of these systems guides users through a relaxation routine. Therefore, a mathematical model is developed in the goal of personalizing the relaxation process. Its objective is to suggest relaxation techniques to a user during a stressful episode based on her or his preferences, history of what worked well and appropriateness for the context. The mental stress monitoring mechanism built into the Ubiquitous Biofeedback systems presented in this Thesis relies on the measurement of Heart Rate Variability (HRV). Therefore, HRV based methods for tracking mental stress accumulation and acute manifestations during long term monitoring have been devised. Also, since HRV signals can be plagued by artifacts, several algorithms are contributed to the effort of correcting such occurrences.
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Hanzo, L. "Adaptive wireless multimedia systems." Thesis, University of Southampton, 2004. https://eprints.soton.ac.uk/260332/.
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Chen, Xiaoming. "Multimedia presentation authoring and browsing in multimedia database systems." FIU Digital Commons, 2002. http://digitalcommons.fiu.edu/etd/2146.
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The purpose of this study was to design and implement multimedia presentation authoring and browsing in multimedia database systems, based on a two-tier client/server architecture.
The major approaches included: (i) Build a client/server multimedia presentation authoring and browsing environment; (ii) Allow query-by-image image retrieval and domain-based browsing through the User Datagram Protocol (UDP) between the Java socket at the client and the Unix socket at the server; (iii) Allow the multimedia presentation authoring by unifying the temporal, spatial and spatio-temporal relations among various media items into Multimedia Augmented Transition Network (MATN) model; (iv) Support the user interaction during the authoring process; (v) Visualize the presentation based on the created MATN models.
As a result, this methodology provided users a flexible environment for heterogeneous media data retrieval and multimedia presentation authoring in multimedia database systems.
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Dobie, Mark Ralph. "Motion analysis in multimedia systems." Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359240.
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Toni, Laura <1982>. "Adaptive wireless multimedia communication systems." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/2117/1/Laura_Toni_tesi.pdf.
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In recent years, due to the rapid convergence of multimedia services, Internet and wireless communications, there has been a growing trend of heterogeneity (in terms of channel bandwidths, mobility levels of terminals, end-user quality-of-service (QoS) requirements) for emerging integrated wired/wireless networks. Moreover, in nowadays systems, a multitude of users coexists within the same network, each of them with his own QoS requirement and bandwidth availability. In this framework, embedded source coding allowing partial decoding at various resolution is an appealing technique for multimedia transmissions. This dissertation includes my PhD research, mainly devoted to the study of embedded multimedia bitstreams in heterogenous networks, developed at the University of Bologna, advised by Prof. O. Andrisano and Prof. A. Conti, and at the University of California, San Diego (UCSD), where I spent
eighteen months as a visiting scholar, advised by Prof. L. B. Milstein and Prof. P. C. Cosman. In order to improve the multimedia transmission quality over wireless channels, joint source and channel coding optimization is investigated in a 2D time-frequency resource block for an
OFDM system. We show that knowing the order of diversity in time and/or frequency domain can assist image (video) coding in selecting optimal channel code rates (source and channel code rates). Then, adaptive modulation techniques, aimed at maximizing the spectral efficiency, are investigated as another possible solution for improving multimedia transmissions. For both slow and fast adaptive modulations, the effects of imperfect channel estimation errors are evaluated, showing that the fast technique, optimal in ideal systems, might be outperformed by the slow adaptive modulation, when a real test case is considered. Finally, the effects of co-channel interference and approximated bit error probability (BEP) are evaluated in adaptive modulation techniques, providing new decision regions concepts, and showing how the widely used BEP
approximations lead to a substantial loss in the overall performance.
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Toni, Laura <1982>. "Adaptive wireless multimedia communication systems." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/2117/.
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In recent years, due to the rapid convergence of multimedia services, Internet and wireless communications, there has been a growing trend of heterogeneity (in terms of channel bandwidths, mobility levels of terminals, end-user quality-of-service (QoS) requirements) for emerging integrated wired/wireless networks. Moreover, in nowadays systems, a multitude of users coexists within the same network, each of them with his own QoS requirement and bandwidth availability. In this framework, embedded source coding allowing partial decoding at various resolution is an appealing technique for multimedia transmissions. This dissertation includes my PhD research, mainly devoted to the study of embedded multimedia bitstreams in heterogenous networks, developed at the University of Bologna, advised by Prof. O. Andrisano and Prof. A. Conti, and at the University of California, San Diego (UCSD), where I spent
eighteen months as a visiting scholar, advised by Prof. L. B. Milstein and Prof. P. C. Cosman. In order to improve the multimedia transmission quality over wireless channels, joint source and channel coding optimization is investigated in a 2D time-frequency resource block for an
OFDM system. We show that knowing the order of diversity in time and/or frequency domain can assist image (video) coding in selecting optimal channel code rates (source and channel code rates). Then, adaptive modulation techniques, aimed at maximizing the spectral efficiency, are investigated as another possible solution for improving multimedia transmissions. For both slow and fast adaptive modulations, the effects of imperfect channel estimation errors are evaluated, showing that the fast technique, optimal in ideal systems, might be outperformed by the slow adaptive modulation, when a real test case is considered. Finally, the effects of co-channel interference and approximated bit error probability (BEP) are evaluated in adaptive modulation techniques, providing new decision regions concepts, and showing how the widely used BEP
approximations lead to a substantial loss in the overall performance.
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Kitinya, Sylivano Chiluli Nonga. "Relational multimedia databases." Thesis, Durham University, 1987. http://etheses.dur.ac.uk/1242/.
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This thesis is concerned with the design and im plementation of a Relational Multimedia Database System, in short RMDBS. RMDBS is designed to efficiently use storage space and manipulate various kinds of data; attribute data, bit-m apped pictures, and program s in binary code. RMDBS is an integrated system which enables the user to manage and control operations on the different forms of data in a user friendly manner. This means that even nonexperienced users can work with the system. The work described in this thesis is novel in that a true multimedia database has been implemented within the framework of a traditional relational DBMS. Previous work in this area has concentrated either in building data base management systems for storing picture-based data or multimedia databases which are not true data base management systems. RMDBS is implemented using the Revelation data base management system.
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Athanasiadis, Tasso, and tas atha@bigpond net au. "Signal Processing Techniques for Mobile Multimedia Systems." RMIT University. Electrical and Computer Engineering, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080123.115457.
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Recent trends in wireless communication systems show a significant demand for the delivery of multimedia services and applications over mobile networks - mobile multimedia - like video telephony, multimedia messaging, mobile gaming, interactive and streaming video, etc. However, despite the ongoing development of key communication technologies that support these applications, the communication resources and bandwidth available to wireless/mobile radio systems are often severely limited. It is well known, that these bottlenecks are inherently due to the processing capabilities of mobile transmission systems, and the time-varying nature of wireless channel conditions and propagation environments. Therefore, new ways of processing and transmitting multimedia data over mobile radio channels have become essential which is the principal focus of this thesis. In this work, the performance and suitability of various signal processing techniques and transmission strategies in the application of multimedia data over wireless/mobile radio links are investigated. The proposed transmission systems for multimedia communication employ different data encoding schemes which include source coding in the wavelet domain, transmit diversity coding (space-time coding), and adaptive antenna beamforming (eigenbeamforming). By integrating these techniques into a robust communication system, the quality (SNR, etc) of multimedia signals received on mobile devices is maximised while mitigating the fast fading and multi-path effects of mobile channels. To support the transmission of high data-rate multimedia applications, a well known multi-carrier transmission technology known as Orthogonal Frequency Division Multiplexing (OFDM) has been implemented. As shown in this study, this results in significant performance gains when combined with other signal-processing techniques such as spa ce-time block coding (STBC). To optimise signal transmission, a novel unequal adaptive modulation scheme for the communication of multimedia data over MIMO-OFDM systems has been proposed. In this system, discrete wavelet transform/subband coding is used to compress data into their respective low-frequency and high-frequency components. Unlike traditional methods, however, data representing the low-frequency data are processed and modulated separately as they are more sensitive to the distortion effects of mobile radio channels. To make use of a desirable subchannel state, such that the quality (SNR) of the multimedia data recovered at the receiver is optimized, we employ a lookup matrix-adaptive bit and power allocation (LM-ABPA) algorithm. Apart from improving the spectral efficiency of OFDM, the modified LM-ABPA scheme, sorts and allocates subcarriers with the highest SNR to low-frequency data and the remaining to the least important data. To maintain a target system SNR, the LM-ABPA loading scheme assigns appropriate signal constella tion sizes and transmit power levels (modulation type) across all subcarriers and is adapted to the varying channel conditions such that the average system error-rate (SER/BER) is minimised. When configured for a constant data-rate load, simulation results show significant performance gains over non-adaptive systems. In addition to the above studies, the simulation framework developed in this work is applied to investigate the performance of other signal processing techniques for multimedia communication such as blind channel equalization, and to examine the effectiveness of a secure communication system based on a logistic chaotic generator (LCG) for chaos shift-keying (CSK).
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Littlejohn, Paul Stephen. "Adaptive flow management of multimedia data with a variable quality of service." Thesis, Rhodes University, 1999. http://hdl.handle.net/10962/d1004863.
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Much of the current research involving the delivery of multimedia data focuses on the need to maintain a constant Quality of Service (QoS) throughout the lifetime of the connection. Delivery of a constant QoS requires that a guaranteed bandwidth is available for the entire connection. Techniques, such as resource reservation, are able to provide for this. These approaches work well across networks that are fairly homogeneous, and which have sufficient resources to sustain the guarantees, but are not currently viable over either heterogeneous or unreliable networks. To cater for the great number of networks (including the Internet) which do not conform to the ideal conditions required by constant Quality of Service mechanisms, this thesis proposes a different approach, that of dynamically adjusting the QoS in response to changing network conditions. Instead of optimizing the Quality of Service, the approach used in this thesis seeks to ensure the delivery of the information, at the best possible quality, as determined by the carrying ability of the poorest segment in the network link. To illustrate and examine this model, a service-adaptive system is described, which allows for the streaming of multimedia audio data across a network using the RealTime Transport Protocol. This application continually adjusts its service requests in response to the current network conditions. A client/server model is outlined whereby the server attempts to provide scalable media content, in this case audio data, to a client at the highest possible Quality of Service. The thesis presents and evaluates a number of renegotiation methods for adjusting the Quality of Service between the client and server. An A djusted QoS renegotiation method algorithm is suggested, which delivers the best possible quality, within an acceptable loss boundary.
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Chen, Qiong. "A flexible multimedia query and presentation interface for multimedia database systems." FIU Digital Commons, 2001. http://digitalcommons.fiu.edu/etd/2143.
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The purpose of this research is to present new methods of active and passive vibration control for flexible structures. The study includes: 1) passive viscoelastic damping treatment; 2 ) active vibration control using layered shape memory alloy (SMA); 3) combined application of viscoelastic damping treatment and SMA; 4) experiments.
In order to maximize damping and save weight of the structure and cost, a partially covered double sandwich cantilever beam model has been presented. It is shown that the double sandwich beam is better than single sandwich beam for some conditions. To take into account of end loads effect of elastic structures such as robot arm or manipulator, a model of partially covered double sandwich cantilever beam with mass at free end is given and discussed. Also a more accurate model (Timoshenko model) is discussed. The experiments were done to verify the theoretical results.
The active vibration control by means of layered shape memory alloy actuator is discussed. The layered structure is easy to implement in real application, especially for the existing structures. The control results are compared and discussed. The temperature effects are discussed.
Also a model with combined application of viscoelastic damping treatment and shape memory alloy layer is presented. Both the vibration characteristics and control results are obtained and discussed. The vibration control results for different control schemes are compared and discussed. The temperature effects are also discussed
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Jiang, Yibin. "On-line multimedia management system." CSUSB ScholarWorks, 2007. https://scholarworks.lib.csusb.edu/etd-project/3221.
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Online Multimedia Management System (OMMS) is a project to provide users to store and share their mutimedia files. The users and administrator can modify and update the multimedia files and database information from a normal web browser. The administrator and users with access have different levels of permission.
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Heimrich, Thomas. "Output constraints in multimedia database systems." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=981079008.
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Stark, Gavin John. "Stream handling in multimedia communication systems." Thesis, University of Cambridge, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311054.
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Young, D. "Interface design for multimedia office systems." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235064.
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Smith, George Barrett. "Evaluating innovative multimedia customer handling systems." Thesis, University of Glasgow, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312671.
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Hou, Yuen Tan. "Resource management in multimedia communication systems." HKBU Institutional Repository, 2003. http://repository.hkbu.edu.hk/etd_ra/478.
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Klaghstan, Merza. "Multimedia data dissemination in opportunistic systems." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI125/document.
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Les réseaux opportunistes sont des réseaux mobiles qui se forment spontanément et de manière dynamique grâce à un ensemble d'utilisateurs itinérants dont le nombre et le déplacement ne sont pas prévisibles. En conséquence, la topologie et la densité de tels réseaux évoluent sans cesse. La diffusion de bout-en-bout d'informations, dans ce contexte, est incertaine du fait de la forte instabilité des liens réseaux point à point entre les utilisateurs. Les travaux qui en ont envisagé l'usage visent pour la plupart des applications impliquant l'envoi de message de petite taille. Cependant, la transmission de données volumineuses telles que les vidéos représente une alternative très pertinente aux réseaux d'infrastructure, en cas d'absence de réseau, de coût important ou pour éviter la censure d'un contenu. La diffusion des informations de grande taille en général et de vidéos en particulier dans des réseaux oppnets constitue un challenge important. En effet, permettre, dans un contexte réseau très incertain et instable, au destinataire d’une vidéo de prendre connaissance au plus vite du contenu de celle-ci, avec la meilleure qualité de lecture possible et en encombrant le moins possible le réseau reste un problème encore très largement ouvert. Dans cette thèse, nous proposons un nouveau mécanisme de diffusion de vidéos dans un réseau opportuniste de faible densité, visant à améliorer le temps d'acheminement de la vidéo tout en réduisant le délai de lecture à destination. La solution proposée se base sur le choix d'encoder la vidéo en utilisant l'encodage SVC, grâce auquel la vidéo se décline en un ensemble de couches interdépendantes (layers), chacune améliorant la précédente soit en terme de résolution, soit en terme de densité, soit en terme de perception visuelle. Notre solution se décline en trois contributions. La première consiste à proposer une adaptation du mécanisme de diffusion Spray-and-Wait, avec comme unités de diffusion, les couches produites par SVC. Les couches sont ainsi diffusées avec un niveau de redondance propre à chacune, adapté à leur degré d'importance dans la diffusion de la vidéo. Notre seconde contribution consiste à améliorer le mécanisme précédent en prenant en compte une granularité plus fine et adaptative en fonction de l'évolution de la topologie du réseau. Cette amélioration a la particularité de ne pas engendrer de coût de partitionnement, les couches vidéos dans l'encodage SVC étant naturellement déclinées en petites unités (NALU) à base desquelles l'unité de transfert sera calculée. Enfin, la troisième contribution de cette thèse consiste à proposer un mécanisme hybride de complétion des couches vidéos arrivées incomplètes à destination. Cette méthode se caractérise par le fait d'être initiée par le destinataire. Elle combine un protocole de demande des parties manquantes aux usagers proches dans le réseau et des techniques de complétion de vidéo à base d’opérations sur les frames constituant la vidéoOpportunistic networks are human-centric mobile ad-hoc networks, in which neither the topology nor the participating nodes are known in advance. Routing is dynamically planned following the store-carry-and-forward paradigm, which takes advantage of people mobility. This widens the range of communication and supports indirect end-to-end data delivery. But due to individuals’ mobility, OppNets are characterized by frequent communication disruptions and uncertain data delivery. Hence, these networks are mostly used for exchanging small messages like disaster alarms or traffic notifications. Other scenarios that require the exchange of larger data are still challenging due to the characteristics of this kind of networks. However, there are still multimedia sharing scenarios where a user might need switching to an ad-hoc alternative. Examples are the cases of 1) absence of infrastructural networks in far rural areas, 2) high costs due limited data volumes or 3) undesirable censorship by third parties while exchanging sensitive content. Consequently, we target in this thesis a video dissemination scheme in OppNets. For the video delivery problem in the sparse opportunistic networks, we propose a solution that encloses three contributions. The first one is given by granulating the videos at the source node into smaller parts, and associating them with unequal redundancy degrees. This is technically based on using the Scalable Video Coding (SVC), which encodes a video into several layers of unequal importance for viewing the content at different quality levels. Layers are routed using the Spray-and-Wait routing protocol, with different redundancy factors for the different layers depending on their importance degree. In this context as well, a video viewing QoE metric is proposed, which takes the values of the perceived video quality, delivery delay and network overhead into consideration, and on a scalable basis. Second, we take advantage of the small units of the Network Abstraction Layer (NAL), which compose SVC layers. NAL units are packetized together under specific size constraints to optimize granularity. Packets sizes are tuned in an adaptive way, with regard to the dynamic network conditions. Each node is enabled to record a history of environmental information regarding the contacts and forwarding opportunities, and use this history to predict future opportunities and optimize the sizes accordingly. Lastly, the receiver node is pushed into action by reacting to missing data parts in a composite backward loss concealment mechanism. So, the receiver asks first for the missing data from other nodes in the network in the form of request-response. Then, since the transmission is concerned with video content, video frame loss error concealment techniques are also exploited at the receiver side. Consequently, we propose to combine the two techniques in the loss concealment mechanism, which is enabled then to react to missing data parts
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Adas, Abdelnaser M. "Supporting multimedia traffic in broadband networks." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/14849.
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Yang, Yin-Wei. "Online multimedia communication system." CSUSB ScholarWorks, 2005. https://scholarworks.lib.csusb.edu/etd-project/2661.
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Online Multimedia Communication System is a project aimed at providing people the ability to store and share their multimedia files. The users and administrator can modify and view the files and database information from a normal web browser. Furthermore, this site offers a secure environment to keep all the users' information private.
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Jeff, Byron A. "A system for using perceiver input to vary the quality of generative multimedia performances." Diss., Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-07142005-023405/.
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Thesis (Ph. D.)--Computing, Georgia Institute of Technology, 2006.Schwan, Karsten, Committee Chair ; Ramachandran, Kishore, Committee Member ; Ahamad, Mustaque, Committee Member ; Yalamanchili, Sudhakar, Committee Member ; Howe, W. Gerry, Committee Member. Vita. Includes bibliographical references.
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Fu, Haohuan. "Efficient multimedia data transmission over heterogeneous networks /." access full-text access abstract and table of contents, 2005. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?mphil-cs-b19887218a.pdf.
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Thesis (M. Phil.)--City University of Hong Kong, 2005."Submitted to Department of Computer Science in partial fulfillment of the requirements for the degree of Master of Philosophy." Includes bibliographical references (leaves 105-108).
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Handel, Peter. "Multimedia delivery in a wireless environment." [Gainesville, Fla.] : University of Florida, 2002. http://purl.fcla.edu/fcla/etd/UFE0000542.
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Shenoy, Prashant J. "Symphony : an integrated multimedia file system /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
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Almeroth, Kevin C. "Support for efficient, scalable delivery of interactive multimedia services." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/12369.
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Wu, Yu, and 吴宇. "Cloud-assisted multimedia content delivery." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/196464.
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Cloud computing, which is among the trendiest computing paradigms in recent years, is believed to be most suitable for supporting network-centric applications by providing elastic amounts of bandwidth for accessing a wide range of resources on the y. In particular, geo-distributed cloud systems are widely in construction nowadays. They span multiple data centers at different geographical locations, thus offering many advantages to large-scale multimedia applications because of the abundance of on-demand storage/bandwidth capacities and their geographical proximity to different groups of users. In this thesis, we investigate the common fundamental challenges in how to efficiently leverage the power of cloud resources to facilitate multimedia content delivery in various modern real world applications, from different perspectives. First, from the perspective of application providers, we propose tractable procedures for both model analysis and system designs of supporting representative large scale multimedia applications in a cloud system, i.e., VoD streaming applications and social media applications, respectively. We further verify the effectiveness of these algorithms and the feasibility of their deployment under dynamic realistic settings in real-life cloud systems. Second, from the perspective of end users, we target our focus at mobile users. The rapidly increasing power of personal mobile devices, dwarfing even high-end devices, is providing much richer contents and social interactions to users on the move, and many more challenging applications are on the horizon. We explore the tough challenges of how to effectively exploit cloud resources to facilitate mobile services by introducing two cloud-assisted mobile systems (i.e., CloudMoV and vSky-Conf), and explain in details their design philosophies and implementation. Finally, from the perspective of the cloud providers, we realize existing data center networks lack the flexibility to support many core services, given our hands-on experiences from working with public cloud systems. One of the specific problem is, “bulk data transfers across geo-distributed datacenters". After formulating a novel and well-formed optimization model for treating the data migration problem, we design and implement a Delay Tolerant Migration (DTM) system based on the Beacon platform and standard OpenFlow APIs. The system realizes a reliable Datacenter to Datacenter (D2D) network by applying the software defined networking (SDN) paradigm. Real-world experiments under realistic network traffic demonstrate the efficiency of the design.published_or_final_version
Computer Science
Doctoral
Doctor of Philosophy
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McNair, Janise Yvette. "Handoff techniques for next generation wireless multimedia systems." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/15971.
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Handley, Mark James. "On internet multimedia conference control." Thesis, University College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285140.
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Amornraksa, Thumrongrat. "Data security for multimedia communications." Thesis, University of Surrey, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298091.
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Zhang, Mingsheng. "A new architecture of multimedia distributed systems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1987. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ44326.pdf.
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Larijani, P. Roohi. "CDMA access to multimedia wireless PCS systems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ37072.pdf.
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Zhang, Mingsheng. "A new architecture of multimedia distributed systems." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=20137.
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This paper proposes a now architecture for distributed multimedia systems, we called it MSZ, which allows users to access multimedia documents in the system. MSZ assumes a system consisting of a not of client machines and a got of server machines. All of these machines are connected through the Internet. A user can ask for a document to be played with the desired quality of service from any server; MSZ is responsible for selecting the beat server that is able to deliver the document to the user most efficiently. The best server satisfies the following properties: (1) It stores the requested document and has the ability to deliver the document to the user (the ability includes its free CPU time and free bandwidth and free memory space). (2) The server is much closer to the user geographically in comparison to other servers in the system, and the related network path has the most available resource, which is more than the service requires. (3) The server has a lighter system load compared to other servers.MSZ is able to minimize the response time and optimize the service quality as much as possible (the users are rejected only when the requested document is unavailable in all servers or servers are all loaded at maximum, or the communication network resource is less than the service required). Also MSZ has the self-learn ability. The more it is used, the better it works.
The system has the ability to detect any degradation in service and to automatically recover during the presentation of the document. A server's failure doesn't affect the whole system and it is very easy for the system to add and remove a server. Generally, MSZ offers a better service to users with less blocking time, less cost and higher quality service.
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Coulson, Geoffrey. "Multimedia application support in open distributed systems." Thesis, Lancaster University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334634.
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Lunn, Andrew Stuart. "A mini cell architecture for multimedia systems." Thesis, Lancaster University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337352.
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Nicolaou, Cosmos Andrea. "A distributed architecture for multimedia communication systems." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385935.
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Kodikara, Patabandi C. K. "Multimedia communications over 3G wireless communication systems." Thesis, University of Surrey, 2004. http://epubs.surrey.ac.uk/844270/.
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This thesis addresses the transmission of video over third generation radio access networks. The first part of the thesis investigates the capabilities of Universal Terrestrial Radio Access Networks (UTRAN) in terms of the provision of multimedia communications. The error performance and traffic requirements of real-time video transmission over circuit switched and packet switched connections are examined. The effect of network parameter settings upon video performances is evaluated, and optimum radio bearer configurations for the transmission of video are derived. A method of estimating received video quality after transmission over error prone environments is developed. The quality estimation is based on a distortion model, which accurately models the overall distortion seen in decoder frame reconstruction. This includes quantisation distortion, concealment distortion, and error propagation. Based on the developed performance model, optimum MTU (Maximum Transfer Unit) size for efficient wireless video communications over a packet switched access network is derived. The second part of the thesis investigates quality enhancement techniques for multimedia traffic transmitted over wireless channels. Quality enhancement is achieved at three levels of the transmission process: link level, application level and system level. Link level quality enhancement techniques are designed to optimise the allocation of link level parameter values according to the media characteristics. A novel Unequal Error Protection scheme and a novel Unequal Power Allocation scheme are designed to exploit the inherent diversity in the subjective importance of different sections of compressed media. The algorithms are developed and analysed for transmission of video over 3G wireless systems. The effectiveness of these algorithms is demonstrated through the results of simulated transmission over a UMTS channel. Application level quality enhancement techniques are designed to explore the time-varying nature of the wireless channel. A number of link adaptation schemes are proposed for real time video communication and real-time video streaming over 3G wireless systems. These algorithms are designed to enhance the perceptual video quality, and the system utilisation. This is achieved by adapting the allocated radio network parameters and the source parameters, according to a feedback channel condition. Simulation results show a significant performance improvement compared to non-adaptive schemes. Finally, system level adaptation techniques are designed for efficient radio resource allocation in multi-user scenarios. Two adaptive resource allocation schemes are proposed and analysed for real-time video communications in a UMTS system. The proposed algorithms are shown to provide improved performances in terms of average received video quality and user satisfaction. Key words: Wireless Communication, Multimedia communication. Video Transmission.
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Larijani, P. Roohi (Parsya Roohi) Carleton University Dissertation Engineering Systems and Computer. "CDMA access to multimedia wireless PCS systems." Ottawa, 1999.
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Jiyapanichkul, Prasit, and jiyapanichkul@yahoo com. "Resource management in broadband multimedia networks." Swinburne University of Technology. Laboratory for Telecommunication Research, 1999. http://adt.lib.swin.edu.au./public/adt-VSWT20050610.100950.
Full textAbstract:
This research deals with optimal resource management in an overloaded broadband
multimedia network. Optimisation is with respect to user satisfaction, where user
satisfaction reflects both the quality of service experienced by connected users and the
dissatisfaction of users blocked from access to the network.
The research focuses on Asynchronous Transfer Mode (ATM) networks and the Internet, because these are the dominant emerging broadband networks which present some fundamental unsolved problems, related to the sharing of resources between mixed traffic types. ATM networks use conservative admission control, which protects
network resources and ensures a high level of service for those admitted to the network, but results in low network efficiency because of low utilisation of resources due to blocking of many potential users. The Internet does not use admission control, with the result that performance degrades progressively as load increases. This causes frustration among users, and lowers the network efficiency due to high levels of congestion.
We propose an optimisation model for each network (ATM networks and the Internet)which is intended to represent the distribution and consumption of key network resources by different traffic types. The model is aimed at maximising performance such that users admitted to the network are offered no less than some minimum acceptable level of quality of service (QoS). The solution is a set of traffic flow rates on each path which results in maximising an objective function value (revenue based on network operator interest or throughput based on customer interest) for a given network
configuration with given user demand. As an example using the ATM network model, we illustrate the application of the model to an ATM network carrying both connection oriented and connectionless traffic. We explore the optimal response to a link failure which in turn causes node overload. As an example using the Internet model, we consider an overloaded network with link bottlenecks and an overloaded Web server, and explore the effect of transferring some server capacity to a mirror site and a proxy server.
For real-time traffic control, the optimisation model is used to assign quotas for bandwidth or connections to selected paths. A control algorithm is implemented to provide maximum performance by admitting requests within the quotas which are obtained from the optimisation model. In an ATM network simulation, the algorithm is used to manage the virtual path (VP) pool in a network which suffers a link failure. A comparison is made between fixed virtual path management (FVPM) and dynamic
virtual path management (DVPM), comparing the revenue achieved by each. This illustrates how DVPM adapts the VP pool in a robust fashion to achieve maximum revenue in the face of a link failure. However, the transient response suggests that benefit could be obtained using non-steady-state solutions. The model is extended by taking network state and traffic parameters into account to control changes in the VP pool to recognise limits to the rate at which traffic can be moved (through the natural
birth-death processes). This scheme is called state dependent virtual path management (SDVPM). Performance evaluation of the new model shows that SDVPM achieves higher revenue than DVPM when the network suffers a link failure that requires a major change to the VP pool. In an Internet simulation, two algorithms are compared for control of access to a proxy server and a set of primary servers. An algorithm based on
optimal flow solutions provides substantially better network performance than a localised heuristic algorithm. In each simulation case (ATM and Internet examples), the performance using a control system based on the steady state optimum flow model is close to the ideal optimal result.
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Mills, Timothy J. "Content modelling in multimedia information retrieval systems : the Cobra retrieval system." Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442405.
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Hsieh, Sheau-Ling 1952. "Distributed multimedia collaborative system framework for tele-healthcare remote consultation systems." Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/284034.
Full textAbstract:
The Remote Consultation and Diagnosis (RCD) in Global Picture Archiving and Communication System (Global PACS) is a unique suite of multimedia telemedicine applications developed at the University of Arizona. The applications support real-time patients' data, image files, audio and video consultation and diagnosis annotation exchanges. The RCD enables joint collaboration between pathologists, radiologists, or physicians while they are at distant geographical locations. This project provides four RCD scenarios, i.e., Case Review, Case Acquire, Store and Forward Analysis, as well as Interactive Diagnosis and Consultation. The RCD Global PACS environment consists of heterogeneous, autonomous, and legacy resources. The Common Object Request Broker Architecture (CORBA), Java Database Connectivity (JDBC), and Java language provide the capability to combine the RCD Global PACS resources into an integrated, interoperable, and scalable system. The underneath technology, including IDL, ORB, Event Service, IIOP, JDBC/ODBC, legacy system wrapping and Java implementation are explored. This distributed collaborative CORBA/JDBC based framework will challenge the advanced, medical information management requirements. It also makes the RCD Global PACS both hardware and software technologically independent. As our research and development extend, we will continue to incorporate the latest advances in computer technology. RCD Global PACS is not another new tool in telemedicine, but rather a new paradigm for the delivery of health services that requires process reengineering, cultural changes, as well as organizational changes. It is a whole new way of practicing in telemedicine. We ensure that the RCD Global PACS project has long-term, comprehensive solutions for today and tomorrow's healthcare needs.
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Rao, Ram Raghavendra. "Audio-visual interaction in multimedia." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/13349.
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Metcalf, Andrew C. "Analysis of multimedia information systems for the U.S. Coast Guard." Thesis, Monterey, Calif. : Naval Postgraduate School, 1992. http://handle.dtic.mil/100.2/ADA247890.
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Koster, Rainer. "Design of a multimedia player with advanced QoS control /." Full text open access at:, 1997. http://content.ohsu.edu/u?/etd,634.
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Gheewala, Adil Adi. "Estimating multimedia instruction performance based on workload characterization and measurement." [Gainesville, Fla.] : University of Florida, 2002. http://purl.fcla.edu/fcla/etd/UFE0000534.
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Liu, Zheng. "Improvements on multimedia security algorithms /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18599.pdf.
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Yankopolus, Andreas George. "Adaptive Error Control for Wireless Multimedia." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5237.
Full textAbstract:
Future wireless networks will be required to support multimedia traffic in addition to traditional best-effort network services. Supporting multimedia traffic on wired networks presents a large number of design problems, particularly for networks that run connectionless data transport protocols such as the TCP/IP protocol suite. These problems are magnified for wireless links, as the quality of such links varies widely and uncontrollably.
This dissertation presents new tools developed for the design and realization of wireless networks including, for the first time, analytical channel models for predicting the efficacy of error control codes, interleaving schemes, and signalling protocols, and several novel algorithms for matching and adapting system parameters (such as error control and frame length) to time-varying channels and Quality of Service (QoS) requirements.
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Willcock, Ian. "Multimedia and live performance." Thesis, De Montfort University, 2012. http://hdl.handle.net/2086/7988.
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The use of interactive multimedia within live performance is now well established and a significant body of exciting and sophisticated work has been produced. However, almost all work in the field seems to start by creating at least some of the software and hardware systems that will provide the infrastructure for the project, an approach which might involve significant duplication of effort. The research described in this thesis sets out to discover if there are common features in the practice of artists from a range of performance backgrounds and, if so, whether the features of a system which might support these common aspects could be established. Based on evidence from a set of interviews, it is shown that there are indeed common factors in work in this field, especially the intensive linking of elements in performances and the use of triggering or cuing. A statement of requirements for a generic system to support work in digital performance is then established based on interview analysis and personal creative work. A general model of live performance, based on set theory, is described which provides a rationale for the integration of digital technology within live performance. A computational model outlining the formal requirements of a general system for use in live performance is then presented. The thesis then describes the creation of a domain specific language specifically for controlling live performance and the development of a prototype reference implementation of a generic system, the Live Interactive Multimedia Performance Toolkit (LIMPT). The system is then evaluated from a number of standpoints including a set of criteria established earlier in the study. It is concluded that, while there are many resources currently used by artists working in digital performance (a comprehensive survey of current resources is presented), none offer the combination of functionality, usability and scalability offered by the prototype LIMPT system. The thesis concludes with a discussion of possible future work and the potential for increased creative activity in multimedia and live performance.
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Nayyar, Vibha Mukul. "Design and Implementation of a Model for Authoring and Presenting Interactive Multimedia Documents." PDXScholar, 1996. https://pdxscholar.library.pdx.edu/open_access_etds/5187.
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Multimedia technology enables direct manipulation of multiple media such as text, image, audio, and video, all integrated into one entity - the multimedia document. Interactive multimedia documents integrate text, images and continuous media such as audio and video, treat them as objects to be presented for a certain duration, and allow users to interact with the presentation. Authoring and presenting interactive multimedia documents imposes new requirements on document representation. We designed the interactive timeline model (ITM) for authoring and presenting interactive multimedia documents. We implemented the model and created a playback tool using the scripting language Tel. ITM uses an enhanced timeline model for representing interactive multimedia scenarios. ITM is a layered model that supports the creation of the logical, temporal, and presentation structures of a multimedia document and emphasizes the separation of content from its structure. The storage layer provides interfaces for creation and storage of media objects like text, images, scripts, choices, and audio. Choice is a media object that allows users to interact with the presentation. A script object causes Tel code to be executed. The composition layer specifies the logical structure and provides interfaces to compose a multimedia document. The presentation layer specifies the temporal and spatial structure of the document and describes the user interface for the playback tool. The run-time layer specifies the interfaces to start and control the flow of the presentation, describes the possible interactions between a user and the presentation at run-time, and specifies the actions to be taken when interaction takes place. ITM allows users to configure the playback tool according to their needs. It provides authors with a mechanism to create new interfaces and register them with the playback tool. To evaluate the design decisions of ITM and verify its usability, we conducted usability tests on the model. We asked a representative sample of end users ( both authors and viewers) to perform realistic tasks using the model. ITM is a powerful model to create and present interactive learning materials and dynamic presentations.
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Youn, Jeongnam. "Video transcoder architectures for networked multimedia applications /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/6117.
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Rody, James. "A presentation agent for distributed multimedia information systems." Thesis, University of Ottawa (Canada), 1996. http://hdl.handle.net/10393/10252.
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Distributed multimedia information systems aim to improve the way people exchange information by supporting a wider variety of media types. These media types include the traditional static media like text, graphics and images as well as the continuous media types like audio and video. Integrating these different types of media within computer based communication systems is no easy task. Indeed, the successful realization of multimedia information systems will depend on the ability of these systems to overcome the problems associated with information integration. There are two types of integration involved in multimedia information systems: spatial integration and temporal integration. This thesis addresses the problem of multimedia information integration; in particular temporal integration. Temporal integration deals with the inter-media and intra-media synchronization of multimedia information. In distributed multimedia information systems, synchronization is compounded by the presence of a computer communication network. Because most computer communication networks are asynchronous communication networks, these networks are not well suited for ensuring constant data delivery rates for continuous media. A remote multimedia presentation agent is designed to handle the synchronization of multimedia information from distributed sources. This remote multimedia presentation agent uses a multimedia document as the information interchange vehicle of the distributed multimedia information system. The remote multimedia presentation agent uses the progressive document retrieval strategy and dynamic quality of service management to help overcome the problems involved in the synchronized retrieval of multimedia information.
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Shi, Zhaogong. "Connection admission control methods for multimedia communication systems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq22016.pdf.
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