Frank Allan Hansen

Integrating the web and the world: contextual trails on the move

This paper presents applications of HyCon, a framework for context aware hypermedia systems. The HyCon framework encompasses annotations, links, and guided tours associating locations and RFID- or Bluetooth-tagged objects with maps, Web pages, and collections of resources. The user-created annotations, links and guided tours, are represented as XLink structures, and HyCon introduces the use of XLink for the representation of recorded geographical paths with annotations and links. The HyCon architecture extends upon earlier location based hypermedia systems by supporting authoring in the field and by providing access to browsing and searching information through a novel geo-based search (GBS) interface for the Web. Interface-wise, the HyCon prototype utilizes SVG on an interface level, for graphics as well as for user interface widgets on tablet PCs and mobile phones.

Tools of contextualization: extending the classroom to the field

Project based education is growing in importance in elementary schools though it is still quite poorly technologically supported, particularly with respect to actively taking advantage of contextual information. Based on an empirical study of teaching and in particular project based education in Danish elementary schools, we present the HyConExplorer, a geospatial hypermedia system supporting project based education and learning outside of the classroom through contextualization of information. More specifically, the HyCon-Explorer provides means for: browsing with your feet, annotating the world, and overview at a glance.

Ubiquitous annotation systems: technologies and challenges

Ubiquitous annotation systems allow users to annotate physical places, objects, and persons with digital information. Especially in the field of location based information systems much work has been done to implement adaptive and context-aware systems, but few efforts have focused on the general requirements for linking information to objects in both physical and digital space. This paper surveys annotation techniques from open hypermedia systems, Web based annotation systems, and mobile and augmented reality systems to illustrate different approaches to four central challenges ubiquitous annotation systems have to deal with: anchoring, structuring, presentation, and authoring. Through a number of examples each challenge is discussed and HyCon, a context-aware hypermedia framework developed at the University of Aarhus, Denmark, is used to illustrate an integrated approach to ubiquitous annotations. Finally, a taxonomy of annotation systems is presented. The taxonomy can be used both to categorize system based on the way they present annotations and to choose the right technology for interfacing with annotations when implementing new systems.

Social web applications in the city: a lightweight infrastructure for urban computing

In this paper, we describe an infrastructure for browsing and multimedia blogging of Web-based information anchored with physical places in an urban environment. The infrastructure is generic in the sense that it may use any means such as GPS, RFID or 2D-barcodes as ubiquitous links anchors to anchor Web-based information, blogs, and services in the physical environment. The infrastructure is inspired from earlier work on open hypermedia, in the sense that the anchoring and blogging functionality can be integrated to augment arbitrary Web sites providing information that is relevant to places or objects in the physical world. The blog and anchor functionality is implemented as a set of Web services running on a server external to the content server. Experiences and design issues from three cases are discussed, which use Semacode-based physical anchoring to support lightweight urban Web applications.

Xspect: bridging open hypermedia and XLink

This paper evaluates the XLink format in comparison with other linking formats. The comparison is based on Xspect, an implementation of XLink. Xspect handles transformation between an open hypermedia format (OHIF) and XLink, and the paper discusses this isomorphic transformation and generalises it to include another open hypermedia format, FOHM. The Xspect system, based on XSLT and Javascript, provides users with an interface to browse and merge linkbases. Xspect supports navigational hypermedia in the form of links inserted on the fly into Web pages, as well as guided tours presented as SVG. Xspect has two implementations: one server-side and one running on the client. Both implementation provide the user with an interface for the creation of annotations. The main result of the paper is a critique of XLink. XLink is shown to be a format well suited for navigational hypermedia, but lacking in more advanced constructs. More problematic are the issues regarding large-scale use, such as evaluating validity and credibility of linkbases, and ensuring general support for a format as flexible as XLink.

Mobile Urban Drama: interactive storytelling in real world environments

This article presents methods and tools for producing location-based Mobile Urban Dramas. In a Mobile Urban Drama, the user becomes the main character in a play that is presented as a multimedia production (through audio, images, animations and videos) on the users mobile phone and in the physical surroundings. The media files are linked via tags (2D barcodes/RFID) or GPS to the real world set as the stage of the drama. The dramaturgical concept is described, and a narrative architecture is introduced. It supports a rich variety of plot graphs implemented in a software framework that supports producing Mobile Urban Dramas. Dramas produced with the framework may span from pure art pieces to structured learning experiences, for example, biology learning framed in a thriller. Experiences from six dramas produced with the framework by a Danish theatre group are discussed. The results are general findings on the concept, the narrative structure, scenographic effects and tools for technical production.

Mobile Learning in Context — Context-aware Hypermedia in the Wild

Modern project-based education requires students to be able to work with digital materials both in and out of the classroom. Field trips are often an integral part of such projects and greatly benefit studentsâ?? learning by allowing them to engage with real-world environments first-hand. However, the infrastructure for accessing context sensitive information and supporting in-situ authoring by students while in the field is often lacking. In this paper we present the HyCon framework for mobile, context-aware, and multi-platform hypermedia that aims at supporting several aspects of fieldtrips and project-based education.

Templates and queries in contextual hypermedia

This paper presents a new definition of context for context-aware computing based on a model that relies on dynamic queries over structured objects. This new model enables developers to flexibly specify the relationship between context and context data for their context-aware applications. We discuss a framework, HyConSC, that implements this model and describe how it can be used to build new contextual hypermedia systems. Our framework aids the developer in the iterative development of contextual queries (via a dynamic query browser) and offers support for con-text matching, a key feature of contextual hypermedia. We have tested the framework with data and sensors taken from the HyCon contextual hypermedia system and are now migrating HyCon to this new framework.

RSS as a distribution medium for geo-spatial hypermedia

This paper describes how the XML based RSS syndication formats used in weblogs can be utilized as the distribution medium for geo-spatial hypermedia, and how this approach can be used to create a highly distributed multi-user annotation system for geo-spatial hypermedia. It is demonstrated, how the HyCon annotation model [2] can be formulated as a RSS 2.0 feed and how such feeds allow annotation threads to be distributed across multiple weblogs and servers.

UrbanWeb: a platform for mobile context-awaresocial computing

UrbanWeb is a novel Web-based context-aware hypermedia platform. It provides essential mechanisms for mobile social computing applications: the framework implements context as an extension to Web 2.0 tagging and provides developers with an easy to use platform for mobile context-aware applications. Services can be statically or dynamically defined in the users context, data can be precached for data intensive mobile applications, and shared state supports synchronization between running applications such as games. The paper discusses how UrbanWeb acquires cues about the users context from sensors in mobile phones, ranging from GPS data, to 2D barcodes, and manual entry of context information, as well as how to utilize this context in applications. The experiences show that the UrbanWeb platform efficiently supports a rich variety of urban computing applications in different scales of user populations.