Distributed multimedia systems

A distributed multimedia system (DMS) is an integrated communication, computing, and information system that enables the processing, management, delivery, and presentation of synchronized multimedia information with quality-of-service guarantees. Multimedia information may include discrete media data, such as text, data, and images, and continuous media data, such as video and audio. Such a system enhances human communications by exploiting both visual and aural senses and provides the ultimate flexibility in work and entertainment, allowing one to collaborate with remote participants, view movies on demand, access on-line digital libraries from the desktop, and so forth. In this paper, we present a technical survey of a DMS. We give an overview of distributed multimedia systems, examine the fundamental concept of digital media, identify the applications, and survey the important enabling technologies.published_or_final_versio

Screen real estate ownership based mechanism for negotiating advertisement display

As popularity of online video grows, a number of models of advertising are emerging. It is typically the brokers – usually the operators of websites – who maintain the balance between content and advertising. Existing approaches focus primarily on personalizing advertisements for viewer segments, with minimal decision-making capacity for individual viewers. We take a resource ownership view on this problem. We view consumers’ attention space, which can be abstracted as a display screen for an engaged viewer, as precious resource owned by the viewer. Viewers pay for the content they wish to view in dollars, as well as in terms of their attention. Specifically, advertisers may make partial payment for a viewer’s content, in return for receiving the viewer’s attention to their advertising. Our approach, named “FlexAdSense”, is based on CyberOrgs model, which encapsulates distributed owned resources for multi-agent computations. We build a market of viewers’ attention space in which advertisers can trade, just as viewers can trade in a market of content. We have developed key mechanisms to give viewers flexible control over the display of advertisements in real time. Specific policies needed for automated negotiations can be plugged-in. This approach relaxes the exclusivity of the relationship between advertisers and brokers, and empowers viewers, enhancing their viewing experience. This thesis presents the rationale, design, implementation, and evaluation of FlexAdSense. Feature comparison with existing advertising mechanisms shows how FlexAdSense enables viewers to control with fine-grained flexibility. Experimental results demonstrate the scalability of the approach, as the number of viewers increases. A preliminary analysis of user overhead illustrates minimal attention overhead for viewers as they customize their policies

A rapid prototyping/artificial intelligence approach to space station-era information management and access

Applications of rapid prototyping and Artificial Intelligence techniques to problems associated with Space Station-era information management systems are described. In particular, the work is centered on issues related to: (1) intelligent man-machine interfaces applied to scientific data user support, and (2) the requirement that intelligent information management systems (IIMS) be able to efficiently process metadata updates concerning types of data handled. The advanced IIMS represents functional capabilities driven almost entirely by the needs of potential users. Space Station-era scientific data projected to be generated is likely to be significantly greater than data currently processed and analyzed. Information about scientific data must be presented clearly, concisely, and with support features to allow users at all levels of expertise efficient and cost-effective data access. Additionally, mechanisms for allowing more efficient IIMS metadata update processes must be addressed. The work reported covers the following IIMS design aspects: IIMS data and metadata modeling, including the automatic updating of IIMS-contained metadata, IIMS user-system interface considerations, including significant problems associated with remote access, user profiles, and on-line tutorial capabilities, and development of an IIMS query and browse facility, including the capability to deal with spatial information. A working prototype has been developed and is being enhanced

Processing Structured Hypermedia : A Matter of Style

With the introduction of the World Wide Web in the early nineties, hypermedia has become the uniform interface to the wide variety of information sources available over the Internet. The full potential of the Web, however, can only be realized by building on the strengths of its underlying research fields. This book describes the areas of hypertext, multimedia, electronic publishing and the World Wide Web and points out fundamental similarities and differences in approaches towards the processing of information. It gives an overview of the dominant models and tools developed in these fields and describes the key interrelationships and mutual incompatibilities. In addition to a formal specification of a selection of these models, the book discusses the impact of the models described on the software architectures that have been developed for processing hypermedia documents. Two example hypermedia architectures are described in more detail: the DejaVu object-oriented hypermedia framework, developed at the VU, and CWI's Berlage environment for time-based hypermedia document transformations

A VISUAL DESIGN METHOD AND ITS APPLICATION TO HIGH RELIABILITY HYPERMEDIA SYSTEMS

This work addresses the problem of the production of hypermedia documentation for applications that require high reliability, particularly technical documentation in safety critical industries. One requirement of this application area is for the availability of a task-based organisation, which can guide and monitor such activities as maintenance and repair. In safety critical applications there must be some guarantee that such sequences are correctly presented. Conventional structuring and design methods for hypermedia systems do not allow such guarantees to be made. A formal design method that is based on a process algebra is proposed as a solution to this problem. Design methods of this kind need to be accessible to information designers. This is achieved by use of a technique already familiar to them: the storyboard. By development of a storyboard notation that is syntactically equivalent to a process algebra a bridge is made between information design and computer science, allowing formal analysis and refinement of the specification drafted by information designers. Process algebras produce imperative structures that do not map easily into the declarative formats used for some hypermedia systems, but can be translated into concurrent programs. This translation process, into a language developed by the author, called ClassiC, is illustrated and the properties that make ClassiC a suitable implementation target discussed. Other possible implementation targets are evaluated, and a comparative illustration given of translation into another likely target, Java

Linked data as medium for distributed Multi-Agent Systems

The conceptual design and discussion of multi-agents systems (MAS) typically focuses on agents and their models, and the elements and effects in the environment which they perceive. This view, however, leaves out potential pitfalls in the later implementation of the system that may stem from limitations in data models, interfaces, or protocols by which agents and environments exchange information. By today, the research community agrees that for this, that the environment should be understood as well as abstraction layer by which agents access, interpret, and modify elements within the environment. This, however, blurs the the line of the environment being the sum of interactive elements and phenomena perceivable by agents, and the underlying technology by which this information and interactions are offered to agents. This thesis proposes as remedy to consider as third component of multi agent systems, besides agents and environments, the digital medium by which the environment is provided to agents. "Medium" then refers to exactly this technological component via which environment data is published interactively towards the agents, and via which agents perceive, interpret, and finally, modify the underlying environment data. Furthermore, this thesis will detail how MAS may use capabilities of a properly chosen medium to achieve coordinating system behaviors. A suitable candidate technology for digital agent media comes from the Semantic Web in form of Linked Data. In addition to conceptual discussions about the notions of digital agent media, this thesis will provide in detail a specification of a Linked Data agent medium, and detail on means to implement MAS around Linked Data media technologies.Sowohl der konzeptuelle Entwurf von, als auch die wissenschaftliche Diskussion über Multi-Agenten-Systeme (MAS) konzentrieren sich für gewöhnlich auf die Agenten selbst, die Agentenmodelle, sowie die Elemente und Effekte, die sie in ihrer Umgebung wahrnehmen. Diese Betrachtung lässt jedoch mögliche Probleme in einer späteren Implementierung aus, die von Einschränkungen in Datenmodellen, Schnittstellen, oder Protokollen herrühren können, über die Agenten und ihre Umgebung Informationen miteinander austauschen. Heutzutage ist sich die Forschungsgemeinschaft einig, dass die Umgebung als solche als Abstraktionsschicht verstanden werden sollte, über die Agenten Umgebungseffekte und -elemente wahrnehmen, interpretieren, und mit ihnen interagieren. Diese Betrachtungsweise verschleiert jedoch die Trennung zwischen der Umgebung als die Sammlung interaktiver Elemente und wahrnehmbarer Phänomene auf der einen Seite, und der zugrundeliegenden Technologie, über die diese Information den Agenten bereitgestellt wird, auf der anderen. Diese Dissertation schlägt als Lösung vor, zusätzlich zu Agenten undUmgebung ein digitales Medium, über das Agenten die Umgebung bereitgestellt wird, als drittes Element von Multi-Agenten-Systemen zu betrachten. Der Begriff "Medium" bezieht sich dann genau auf diese technologische Komponente, über die Umgebungsinformationen Agenten interaktiv bereitgestellt werden, und über die Agenten die zugrundeliegenden Daten wahrnehmen, interpretieren, und letztendlich modifizieren. Desweiteren wird diese Dissertation aufzeigen, wie die Eigenschaften eines sorgfältig gewählten Mediums ausgenutzt werden können, um ein koordiniertes Systemverhalten zu erreichen. Ein geeigneter Kandidat für ein digitales Agentenmedium findet sich im Ökosystem des „Semantic Web”, in Form von „Linked Data”, wörtlich („verknüpfte Daten”). Zusätzlich zu einer konzeptionellen Diskussion über die Natur digitaler Agenten- Media, spezifiziert diese Dissertation „Linked Data” als Agentenmedium detailliert aus, und beschreibt im Detail die Mittel, wie sich MAS um Linked Data Technologien herum implementieren lassen

Synchronization of Multi-Sourced Multimedia Data for Heterogeneous Target Systems

Accessing multimedia information in a networked environment introduces problems to an application designer that don't exist when the same information is fetched locally. These problems include "competing" for the allocation of network resources across applications, synchronizing data arrivals from various sources within an application, and supporting multiple data representations across heterogeneous hosts. In this paper, we present a general framework for addressing these problems that is based on the assumption that time-sensitive data can only be controlled by having the application, the operating system(s) and a set of active, intelligent information object coordinate their activities based on a

An Architecture for distributed multimedia database systems

In the past few years considerable demand for user oriented multimedia information systems has developed. These systems must provide a rich set of functionality so that new, complex, and interesting applications can be addressed. This places considerable importance on the management of diverse data types including text, images, audio and video. These requirements generate the need for a new generation of distributed heterogeneous multimedia database systems. In this paper we identify a set of functional requirements for a multimedia server considering database management, object synchronization and integration, and multimedia query processing. A generalization of the requirements to a distributed system is presented, and some of our current research and developing activities are discussed