TELEPORT – Towards immersive copresence

TELEPORT is an experimental teleconferencing system with the goal of enabling small groups of people, although geographically separated, to meet as if face to face. The innovative features of the system include the use of full-wall display surfaces, “merging” of real and virtual environments, viewer tracking, and real-time compositing of live video with synthetic backgrounds.     

Towards user centred design (UCD) in architecture based on immersive virtual environments

This paper describes a generic concept of how to combine the experience of user centred design (UCD) in the field of Human Computer Interaction (HCI) with the traditional approach of participatory design (PD) in an architectural design process. Even if some basic requirements of this generic method are not available yet, this paper will also describe an approach, which enables planners even now to involve end users by using virtual environments (VE) as immersive and spatial prototype. It will be described and illustrated by the way of example using the building project Centre of Virtual Engineering of the Fraunhofer Institute for Industrial Engineering (IAO) in Stuttgart. It demonstrates that the transfer of the UCD approach to architectural planning combined with the provision of an adequate prototype can make a significant contribution towards an increase in quality and performance in building and construction projects.     

The Human Communication Space: Towards I-centric Communications

In the last few years, a variety of concepts for service integration and corresponding systems have been developed. On the one hand, they aim for the interworking and integration of classical telecommunications and data communications services. On the other, they are focusing on universal service access from a variety of end-user systems. Many of the technical problems, resulting from the service integration, and service personalisation have been solved during the last years. However, all these systems are driven by the concept of providing several technologies to users by keeping the peculiarity of each service.  Looking at humans’ communication behaviour and their communication space, it is obvious that human beings interact habitually in a set of contexts with their environment. The individual information preferences and needs, persons to interact with, and the set of devices controlled by each individual define their personal communication space. Following this view, a new approach is to build communication systems not on the basis of specific technologies, but on the analysis of the individual communication spaces. The result is a communication system adapted to the demands of each individual (I-centric). The communication system will act on behalf of users’ demands, reflecting recent actions to enable profiling and self-adaptation to contexts and situations.  In this paper, we introduce I-centric Communications, an approach to design communication systems that adapt themselves to the individual communication space and individual environment and situation. In this context “I” means I, or individual, “Centric” means adaptable to I requirements and a certain user environment.     

Exploring the Suitability of Virtual Environments for Safety Training: Signals, Norms and Ambiguity in a Simulated Emergency Escape

This study aims at exploring the suitability of virtual environments for safety training in large public spaces. A virtual library was constructed which simulated many of the physical and normative characteristics of the ‘real’ university library which was the target of the virtual safety training project. In the virtual library, two different types of signals (fixed red signs vs. moving green arrows) for guiding people to the emergency exits were presented, and their efficacy on escape times was tested in three different conditions, differing with respect to the distance of participants from the escape exits (measured according to the number of corners separating participants from direct visual discovery of the emergency exit). No significant differences between the different kinds of signals were found, whereas surprising discrepancies among the three conditions appeared. The differences in performance in the three conditions were contingent upon the presence in the virtual library of peculiar environmental features embodying social norms – like a red ribbon indicating no transit. Uncertainty about the sense of such normative features in the context of the simulated emergency made some participants prone to peculiar knowledge-based errors consisting of inadequate sense-making of the normative aspects of the ongoing situation. This kind of error shows that the simulation succeeded in capturing one of the crucial characteristics of ‘real’ social context: ambiguity, which mostly depends on the fact that the social norms structuring public spaces and defining their legitimate uses are often ill defined and context dependent. Every valid experience in safety training requires coping with ambiguity in situations.     

Citywide: Supporting Interactive Digital Experiences Across Physical Space

The Citywide project is exploring ways in which technology can provide people with rich and engaging digital experiences as they move through physical space, including historical experiences, performances and games. This paper describes some initial results and experiences with this project based upon two prototype demonstrators. In the first, we describe an application in which a search party explores an archaeological site, uncovering enacted scenes within the virtual world that are of a historical relevance to their particular physical location. In the second, we describe a museum experience where participants explore an outdoors location, hunting for buried virtual artifacts that they then bring back to a museum for a more detailed study. Our demonstrators employ a varied set of devices, including mobile wireless interfaces for locating hotspots of virtual activity when outdoors, to give different experiences of the virtual world depending upon location, task, available equipment and accuracy of tracking. We conclude by discussing some of the potential advantages of using an underlying shared virtual world to support interactive experiences across extended physical settings.     

Design and evaluation of an adaptive virtual guide for Web applications

Most applications accessible through the Web suffer from a noticeable lack of support for adapting to the different information needs that different users may have regarding a certain topic. However, completely automatic adaptive support can still be confusing for users who may not understand the reasons for the dynamic change in the behaviour of an application. In this paper, we present a possible solution to provide adaptive support that does not disorient the user. The solution integrates a virtual January 18, assistant that is able to provide adaptive support in an adaptable application. We discuss an example of the application of this approach involving the support of Web visits to virtual museums. We then present the results of an empirical usability test of such an application. Published online: 29 January 2002     

Towards robust multi-cue integration for visual tracking

Abstract. Even though many of today's vision algorithms are very successful, they lack robustness, since they are typically tailored to a particular situation. In this paper, we argue that the principles of sensor and model integration can increase the robustness of today's computer-vision systems substantially. As an example, multi-cue tracking of faces is discussed. The approach is based on the principles of self-organization of the integration mechanism and self-adaptation of the cue models during tracking. Experiments show that the robustness of simple models is leveraged significantly by sensor and model integration.     

Usage of multisensory information in scientific data sensualization

Multisensory scientific data sensualization methods that utilize virtual reality technology permit the use of several human sensations, such as visual, acoustic, and tactile sensation to display numerical data. The purposes of multisensory data sensualization can be classified as follows: (a) representing the relationships between different kinds of data; (b) displaying data utilizing sensory integration; and (c) representing conditions using the compound image. By using multisensory information, computers increase the ability to express data. However, these methods lead us to the question of which sensation should be used to display data most effectively. In this study, a multisensory data sensualization environment was developed in which color, loudness, sound frequency, and air flow pressure could be used to display scientific data. In particular, a wind sensation display prototype using air flow pressure was developed to generate tactile sensation. A basic experiment was conducted on sensory interference when subjects used two kinds of sensations simultaneously. From these results, guidelines for the usage of multisensory information for each purpose is proposed.     

A synchronization algorithm for distributed multimedia environments

Network synchronization plays a significant role in transmitting multimedia objects over computer networks. Even packets from a single channel must be synchronized due to the problems in a packet switching environment, such as network jitter, frequency, and time offsets. We present an algorithm that determines the set of packets generated periodically by various participants arriving at a node. The basic advantage of the proposed algorithm is that the receiver estimates the reference times (expected arrival times of the packets) and achieves synchronization, without knowledge of the packet delays. The accuracy is improved and the complexity is reduced by predicting the time/frequency offsets between the clocks at the source and the mixer. The error is calculated by the Chernoff bound, demonstrated by simulation, and shown to be acceptable in practical applications.     

A methodology for the evaluation of travel techniques for immersive virtual environments

We present a framework for the analysis and evaluation oftravel, or viewpoint motion control, techniques for use in immersive virtual environments (VEs). In previous work, we presented a taxonomy of travel techniques and a set of experiments mapping parts of the taxonomy to various performance metrics. Since these initial experiments, we have expanded the framework to allow evaluation of not only the effects of different travel techniques, but also the effects of many outside factors simultaneously. Combining this expanded framework with the measurement of multiple response variables epitomises the philosophy oftestbed evaluation. This experimental philosophy leads to a deeper understanding of the interaction and the technique(s) in question, as well as to broadly generalisable results. We also present an example experiment within this expanded framework, which evaluates the user's ability to gather information while travelling through a virtual environment. Results indicate that, of the variables tested, the complexity of the environment is by far the most important factor.     

Towards cognitive evaluation of computer-drawn sketches

This paper seeks to raise visual comparisons beyond subjective opinions into evidence-based visual reasoning. It provides an informal deductive analysis of the marks in sketches derived with two competing line-filtering algorithms. This prompted the novel speculation that the visual system might be placing some types of anomalies in the foreground of mental 3D space, where they can be ignored. A brief survey is provided to encourage informed debate. Although the proposed cognitive computation was not automated, it justified the rejection of the Douglas–Peucker algorithm in favour of Visvalingam's algorithm in subsequent research within the Cartographic Information Systems Research Group (CISRG).     

Orientation lightmaps for photon tracing in complex environments

We present a method that makes the use of photon tracing methods feasible for complex scenes when a totally accurate solution is not essential. This is accomplished by using orientation lightmaps, which average the illumination of complex objects depending on the surface normal. Through this averaging, they considerably reduce the variance of the stochastic solution. In order to use these specialised lightmaps, which consume comparatively small amounts of memory, no changes have to be made to the basic photon-tracing algorithm. Also, they can be freely mixed with normal lightmaps. This gives the user good control over the amount of inaccuracy he introduces by their application. The area computations necessary for their insertion are performed using a stochastic sampling method that performs well for highly complex objects.     

Shared virtual worlds for education: the ExploreNet experiment

ExploreNet is an experimental environment for creating and delivering networked “virtual worlds.” This system's style of user interaction was inspired by the concept of a “habitat” as first articulated in the LucasFilm's Habitat system. Players enter and interact in a habitat via their animated alter egos, called “avatars.” Habitats may be created for many purposes, including social interaction, entertainment and education. Our focus has been to facilitate the creation of habitats in which virtual communities of learners and mentors interact. This paper presents details of the current ExploreNet system, including its user interface, the means it provides for creating complex behaviors, details of its implementation, the outcomes of several experiments using this system, and our plans for its natural migration to a World Wide Web-based system.     

Intermediate-level feature extraction in novel parallel environments

Abstract. Parallel systems provide an approach to robust computing. The motivation for this work arises from using modern parallel environments in intermediate-level feature extraction. This study presents parallel algorithms for the Hough transform (HT) and the randomized Hough transform (RHT). The algorithms are analyzed in two parallel environments: multiprocessor computers and workstation networks. The results suggest that both environments are suitable for the parallelization of HT. Because scalability of the parallel RHT is weaker than with HT, only the multiprocessor environment is suitable. The limited scalability forces us to use adaptive techniques to obtain good results regardless of the number of processors. Despite the fact that the speedups with HT are greater than with RHT, in terms of total computation time, the new parallel RHT algorithm outperforms the parallel HT. Received: 8 December 2001 / Accepted: 5 June 2002 Correspondence to: V. Kyrki     

Towards shape representation using trihedral mesh projections

Z -coordinates} of the vertices are completely governed by the Z-coordinates assigned to four selected ones. This allows describing the spatial polygonal mesh with just its 2D projection plus the heights of four vertices. As a consequence, these projections essentially capture the “spatial meaning” of the given surface, in the sense that, whatever spatial interpretations are drawn from them, they all exhibit essentially the same shape. Published online: 5 February 2003     

Towards a design code of practice for universal access in health telematics

This paper presents a brief overview of the European Commission funded Thematic Network (Working Group) “Information Society for All”-IS4ALL (IST-1999-14101). IS4ALL aims to establish a wide, interdisciplinary and closely collaborating network of experts to provide the European Health Telematics industry with a comprehensive code of practice on how to appropriate the benefits of universal design. This paper outlines the project’s main objectives and technical approach in the context of universal access. Published online: 9 April 2002     

Using Personal Traces in Context Space: Towards Context Trace Technology

Wearables are often described with a focus on providing the user with wearable information access and communication means. The contextual information retrieval aspect is, however, an essential feature of such systems, as in, for example, the Remembrance Agent [1] where manually entered search-terms are used for presenting relevant situational information, or as in different location-based systems [2]. In this position paper we outline a general framework of contextually aware wearable systems, and suggest how such mechanisms, collecting massive traces of the user context, may lead to several other interesting uses in what we will call context trace technology.