Hypermedia and the semantic web: a research agenda

Until recently, the Semantic Web was little more than a name for the next generation Web infrastructure as envisioned by its inventor, Tim Berners-Lee. Now, with the introduction of XML and RDF, and new developments such as RDF Schema and DAML+OIL, the Semantic Web is rapidly taking shape. In this paper, we first give an overview of the state-of-the-art in Semantic Web technology, the key relationships with traditional hypermedia research, and a comprehensive reference list to various sets of literature (Hypertext, Web and Semantic Web). The core of the paper presents a research agenda b

The stability of microbially reduced U(IV); impact of residual electron donor and sediment ageing

AbstractThe stimulation of microbial U(VI) reduction to precipitate insoluble U(IV) has been proposed as a means of remediating mobile uranium groundwater contamination. Crucial to the success of such a remediation strategy is determining the longevity of U(IV) biominerals in the subsurface, particularly if the groundwater becomes oxidising. Here we describe experiments to assess the susceptibility of microbially-reduced U(IV) to oxidative remobilisation both via aeration and by the addition of nitrate at environmentally-relevant conditions. Additional factors examined include the possibility of biogenic U(IV) becoming more crystalline (and potentially more recalcitrant) during a period of ageing, and the role played by residual electron donor in controlling the long-term fate of the uranium. Biogenic U(IV) was precipitated as a non-crystalline U(IV) or “monomeric” phase, with a small but increasing contribution to the EXAFS spectra from nanocrystalline uraninite occurring during 15months of ageing. Despite this, no evidence was observed for an increase in recalcitrance to oxidative remobilisation. However, the presence of residual electron donor post-biostimulation was shown to exert a strong control on U(IV) reoxidation kinetics, highlighting the importance of maintaining the presence of electron donor in the subsurface, in order to protect biogenic U(IV) from oxidative remobilisation

Integrating multimedia characteristics in web-based document languages

A single multimedia document model needs to include a wide range of different types of information. In particular, information about space and time is essential for determining the spatial and temporal placement of elements within a presentation. Each information type included in a document model requires its own structuring mechanisms. The language used to express the document model has to be able to encapsulate the plurality of required structures. While this is a process that can be carried out relatively easily during the initial design of a language, it is more difficult in the case t

The Use of SMIL: Multimedia Research Currently Applied on a Global Scale

This paper describes the current use of the multimedia standard SMIL. SMIL features that relate to active areas of multimedia research are discussed. SMIL current implementation in existing browsers is described. Examples from the Web of SMIL applications representing different types of multimedia are presented. These discussions together provide an overview of how SMIL currently addresses the needs of multimedia distributed on the Web

The application of rhetorical structure theory to interactive news program generation from digital archives

Rhetorical structure theory (RST) provides a model of textual function based upon rhetoric. Initially developed as a model of text coherence, RST has been used extensively in text generation research, and has more recently been proposed as a basis for multimedia presentation generation. This paper investigates the use of RST for generating video presentations having a rhetorical form, using models of the rhetorical roles of video components, together with rules for selecting components for presentation on the basis of their rhetorical functions. An RST model can provide a predefined link structure providing viewers with options for obtaining and dynamically modifying rhetorically coherent video presentations from video archives and databases. The use of an RST analysis for interactive presentation generation may provide a more powerful rhetorical device than conventional linear video presentation. Conversely, making alternative RST analyses of the same video data available to users can have the effect of encouraging closer and more independent viewer analysis of the material, and discourage taking any particular rhetorical presentation at face value

Mix'n'Match: Exchangeable Modules of Hypermedia Style

Making hypermedia adaptable for multiple forms of presentation involves enabling multiple distinct specifications for how a given collection of hypermedia can have its presentation generated. The Standard Reference Model for Intelligent Multimedia Presentation Systems describes how the generation of hypermedia presentation can be divided into distinct but cooperating layers. Earlier work has described how specifications for generating presentations can be divided into distinct modules of code corresponding to these layers. This paper explores how the modules for each layer of a presentation specification can be exchanged for another module encoded for that layer and result in the whole specification remaining well functioning. This capability would facilitate specifying presentation generation by allowing for the use of pre-programmed modules, enabling the author to focus on particular aspects of the presentation generation process. An example implementation of these concepts that uses current and developing Web standards is presented to illustrate how wide-spread modularized presentation generation might be realized in the near future

Towards a multimedia formatting vocabulary

Time-based, media-centric Web presentations can be described declaratively in the XML world through the development of languages such as SMIL. It is difficult, however, to fully integrate them in a complete document transformation processing chain. In order to achieve the desired processing of data-driven, time-based, media-centric presentations, the text-flow based formatting vocabularies used by style languages such as XSL, CSS and DSSSL need to be extended. The paper presents a selection of use cases which are used to derive a list of requirements for a multimedia style and transformation formatting vocabulary. The boundaries of applicability of existing text-based formatting models for media-centric transformations are analyzed. The paper then discusses the advantages and disadvantages of a fully-fledged time-based multimedia formatting model. Finally, the discussion is illustrated by describing the key properties of the example multimedia formatting vocabulary currently implemented in the back-end of our Cuypers multimedia transformation engine

Implementing adaptability in the standard reference model for intelligent multimedia presentation systems

This paper discusses the implementation of adaptability in environments that are based on the Standard Reference Model for Intelligent Multimedia Presentation Systems. This adaptability is explored in the context of style sheets, which are represented in such formats as DSSSL. The use of existing public standards and tools for this implementation of style sheet-based adaptability is described. The Berlage environment is presented, which integrates these standards and tools into a complete storage-to-presentation hypermedia environment. The integration of the SRM into the Berlage environment is introduced in this work. This integration illustrates the issues involved in implementing adaptability in the model

Supporting Adaptive and Adaptable Hypermedia Presentation Semantics

Having the content of a presentation adapt to the needs, resources and prior activities of a user can be an important benefit of electronic documents. While part of this adaptation is related to the encodings of individual data streams, much of the adaptation can/should be guided by the semantics in and among the objects of the presentation. The semantics involved in having hypermedia presentations adapt can be divided between adaptive hypermedia, which adapts autonomously, and adaptable hypermedia, which requires presentationexternal intervention to be adapted. Understanding adaptive and adaptable hypermedia and the differences between them helps in determining the best manner with which to have a particular hypermedia implementation adapt to the varying circumstances of its presentation. The choice of which type of semantics to represent can affect speed of the database management system processing them. This paper reflects on research and implementation approaches toward both adaptive and adaptable hypermedia and how they apply to specifying the semantics involved in hypermedia authoring and processing. We look at adaptive approaches by considering CMIF and SMIL. The adaptable approaches are represented by the SGML-related collection of formats and the Standard Reference Model (SRM) for IPMS are also reviewed. Based on our experience with both adaptive and adaptable hypermedia, we offer recommendations on how each approach can be supported at the data storage level