This thesis addresses issues related to the development of Collaborative Virtual Environments (CVEs) for architectural design use. Today a new level of complexity has been brought to the meaning of virtuality by the creation of network-based virtual communities and the use of avatars along with multimedia which provides the technology for remote presence and collaborative experience. Communication and especially collaboration among design teams are now key factors in making the design process faster and more efficient in order to achieve increased competitiveness in the construction market. The objective of this thesis is to present a tool that is capable of creating 3D shapes in a shared VR environment, therefore allowing the evolution of the design to be a shared process. Along with its companion thesis (Conti, 2002) it gives the description of a framework and software prototype which could help practitioners using Virtual Reality technology by being a new interface for collaborative design at the early stages of the design process. The prototype system that is described here is called Java™ Collaborative Architectural Design tool in Virtual Reality JCAD-VR) and this thesis presents a description of its collaborative architecture. This thesis gives a description of the phases and technical solutions in the development of the network architecture and collaborative features of the JCAD-VR system. In addition, several different communication tools were used to enhance communication and the flow of information among the design teams and they are integrated in a Virtual Environment specifically created for architects. After the description of the software development the results are given of a test of the collaborative architecture of JCAD-VR and its ease of use in a real multi participant design experiment which show the potential and efficiency of using CVEs in architecture.

The first goal of this study is to test the prediction that children who perceive similarity between a novel physical event and the real world will be more likely to express belief in the reality of a novel character involved in the event than children who do not perceive such similarity. The second goal is to test the effects of familiarity on similarity judgements, reality status beliefs, and their association. In this study, children ages 4 and 6 years were visited 5 times and were repeatedly told about a novel character performing either a highly similar, moderately dissimilar, or a highly dissimilar physical event. Their similarity judgements and reality status judgements were solicited on days 1 and 5. Results revealed high rates of association between similarity and reality status beliefs for the highly similar and moderately dissimilar events but low levels of association for the highly dissimilar event on day 1. With repeated exposure, children’s positive similarity judgements increased for the highly dissimilar event leading to higher rates of association. / text

published_or_final_version / Computer Science / Master / Master of Philosophy

The thesis examines the nature of the "real" in the cinema; I overview the theories that are historically used, and offer some alternative models. First, I survey how the "real" has been traditionally theorized in film theory. The realist/anti-realist debate is addressed; the psycholinguistic theory of Jacques Lacan and Jean Baudrillard's postmodern model of the hyperreal are reexamined in light of their profound effect on film theory's model of the cinematic "real." I argue against these theories as models of spectatorship and the "real" because of their hermetic nature. / I then consider Walter Benjamin's Passagen-Werk and the "dialectical image" as an alternative approach to the problems of the "real." Benjamin's model takes into consideration both the epistemological nature of the image and the problematics of cultural context. In conclusion, I analyze the problem of mediation in any model of the cinematic "real."

The temporal bone is a complicated bone in which diseases can necessitate surgery. Current surgery training methods in this area include human cadaver, physical and virtual models. The objective of this research is to modify a haptic system as a part of a Mixed Reality (MR) temporal bone surgery simulator. The simulator employs a haptic model of soft tissue, which is sufficiently simple not to alter the performance characteristics of the haptic system, overlaid on a physical model of the bone to include advantages of both. A gripper has been developed to retrofit a haptic device with a surgical drill. Device characteristics are explored and modified to compensate for gravity effects of the gripper on the system and to transmit the haptic interaction point to the drill tip, where the soft tissue model’s forces should be felt. This developed system should contribute in providing a more realistic surgery simulation.

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The temporal bone is a complicated bone in which diseases can necessitate surgery. Current surgery training methods in this area include human cadaver, physical and virtual models. The objective of this research is to modify a haptic system as a part of a Mixed Reality (MR) temporal bone surgery simulator. The simulator employs a haptic model of soft tissue, which is sufficiently simple not to alter the performance characteristics of the haptic system, overlaid on a physical model of the bone to include advantages of both. A gripper has been developed to retrofit a haptic device with a surgical drill. Device characteristics are explored and modified to compensate for gravity effects of the gripper on the system and to transmit the haptic interaction point to the drill tip, where the soft tissue model’s forces should be felt. This developed system should contribute in providing a more realistic surgery simulation.

The problems of maintaining software systems are well documented. The increasing size and complexity of modern software serves only to worsen matters. Software maintainers are typically confronted with very large and very complex software systems, of which they may have little or no prior knowledge. At this stage they will normally have some maintenance task to perform, though possibly little indication of where or how to start. They need to investigate and understand the software to some extent in order to begin maintenance. This understanding process is termed program comprehension. There are various theories on program comprehension, many of which put emphasis on the construction of a mental model of the software within the mind of the maintainor. These same theories hypothesise a number of techniques employed by the maintainer for the creation and revision of this mental model. Software visualisation attempts to provide tool support for generating, supplementing and verifying the maintainer’s mental model. The majority of software visualisations to date have concentrated on producing two dimensional representations and animations of various aspects of a software system. Very little work has been performed previously regarding the issues involved in visualising software within a virtual reality environment. This research represents a significant first step into this exciting field and offers insight into the problems posed by this new media. This thesis provides an identification of the possibilities afforded byU3D graphics for software visualisation and program comprehension. It begins by defining seven key areas of 3D software visualisation, followed by the definition of two terms, visualisation and representation. These two terms provide a conceptual division between a visualisation and the elements of which it is comprised. This division enables improved discussion of the properties of a 3D visualisation and particularly the idenfification of properties that are desirable for a successful visualisation. A number of such desirable properties are suggested for both visualisations and representations, providing support for the design and evaluation of a 3D software visualisation system. Also presented are a number of prototype visualisations, each providing a different approach to the visualisation of a software system. The prototypes help demonstrate the practicalities and feasibility of 3D software visualisation. Evaluation of these prototypes is performed using a variety of techniques, the results of which emphasise the fact that there is substantial potential for the application of 3D graphics and virtual reality to software visualisation.

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