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In this thesis visual search experiments are devised to explore the feasibility of an eye gaze driven search mechanism. The thesis first explores gaze behaviour on images possessing different levels of saliency. Eye behaviour was predominantly attracted by salient locations, but appears to also require frequent reference to non-salient background regions which indicated that information from scan paths might prove useful for image search. The thesis then specifically investigates the benefits of eye tracking as an image retrieval interface in terms of speed relative to selection by mouse, and in terms of the efficiency of eye tracking mechanisms in the task of retrieving target images. Results are analysed using ANOVA and significant findings are discussed. Results show that eye selection was faster than a computer mouse and experience gained during visual tasks carried out using a mouse would benefit users if they were subsequently transferred to an eye tracking system. Results on the image retrieval experiments show that users are able to navigate to a target image within a database confirming the feasibility of an eye gaze driven search mechanism. Additional histogram analysis of the fixations, saccades and pupil diameters in the human eye movement data revealed a new method of extracting intentions from gaze behaviour for image search, of which the user was not aware and promises even quicker search performances. The research has two implications for Content Based Image Retrieval: (i) improvements in query formulation for visual search and (ii) new methods for visual search using attentional weighting. Futhermore it was demonstrated that users are able to find target images at sufficient speeds indicating that pre-attentive activity is playing a role in visual search. A current review of eye tracking technology, current applications, visual perception research, and models of visual attention is discussed. A review of the potential of the technology for commercial exploitation is also presented.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 172-179).

The focus of this research was to examine how effectively augmented reality (AR) displays, generated with a wearable computer, could be used for aiding an operator performing a manufacturing assembly task. The research concentrated on comparing two technologies for generating augmented reality displays (opaque vs. see-through), with two current types of assembly instructions (a traditional assembly instruction manual vs. computer aided instruction). The study was used to evaluate the effectiveness of the wearable based augmented reality compared to traditional instruction methods, and was also used to compare two types of AR displays in the context of an assembly task. For the experiment, 15 subjects were asked to assemble a computer motherboard using the four types of instruction: paper manual, computer aided, an opaque AR display, and a see-through AR display. The study was run as a within subjects design, where subjects were randomly assigned the order of instruction media. For the AR conditions, the augmented environments were generated with a wearable computer, and viewed through two types of monocular, head-mounted displays (HMD). The first type of HMD was a monocular opaque HMD, and the second was a monocular see-though HMD. Prior to the experiment, all subjects performed a brief training session teaching them how to insert the various components of the motherboard in their respective slots. The time of assembly and assembly errors were measured for each type of media, and a questionnaire was administered to each subject at the end of each condition, and at the end of the experiment to determine the usability of the four instructional media. The results of the experiment indicated that both augmented reality conditions were more effective instructional aids for the assembly task than either the paper instruction manual or the computer aided instruction. The see-through HMD resulted in the fastest assembly times followed by the opaque HMD, the computer aided instruction, and the paper instructions respectively. In addition, subjects made fewer errors using the AR conditions compared to the other two types of instructional media. However, while the two AR conditions were a more effective instructional media when time was the response measure, there were still some important usability issues associated with the AR technology that were not present in the non-AR conditions. Many of the subjects indicated that both types of HMDs were uncomfortable, and over half expressed concerns about poor image contrast with the see-through HMDs. Finally, this thesis discusses the results of this study as well as implications for the design and use of AR and wearable computers for manufacturing assembly tasks. / Master of Science

This thesis introduces the original idea that it is possible, and productive, to consider the ‘blending’ of (or deliberate creative combining of methods from) the fields of fine art practice and science practice, using selected empirical research methods to investigate constructions of self and self-identity that emerge between disciplines. In particular, the thesis investigates how the scientific aspects of modern computer games, for instance, can be seen to affect emotional responses from viewers and how those responses are, in turn, affected by the ‘blending’ of aesthetic concerns with consideration of alternative cognitive processes that induce relaxation to connect with participant-players’ self-identities. This process created a method to access cognitive processes, hitherto unexplored by computer-game developers. This research locates its arguments primarily in and between the disciplines, Art and Game Studies and supports the findings with examples taken from art practice and with theories of Psychology and Gaming. This thesis documents the creation of the author’s original hybrid ‘art- work-game’, known as ‘Star World’. It describes the process of ‘Star World’s’ creation, with analysis of the efficacy of this environment as a space where the mapping of narrative, and where perceptual and interactive ‘blendings’ of self and self-identity were employed and tested, with both qualitative and empirical studies of the experiences and perceptions of participant-players. The research focuses on how the distinctive abstract environment, ‘Star World’, affords and facilitates personal expression and interaction for computer-game players. It reveals specific cognitive processes undergone by participant-players; evidence that supports and validates the conjecture that participant-players use personal frames of reference when navigating, exploring and interpreting computer games. Teach-back protocols and their impact are shown to improve the interactivity and immersive potential of the environment. Overall, this thesis classifies ‘haute game’ rules that are formulated to identify virtual environments creating unique, alternative ‘blendings’ with participant-players and assembles a framework for developers to pursue, when producing original computer-game genres. It offers an innovative case study of value to future scholars of Game Studies, as well as to game developers, with cautionary examples provided to assist in dealing with situations where emotional states are accessed by game play. This thesis highlights the potential of interactive art and game design to produce beneficial outcomes for its participant-players, moreover, it demonstrates, with empirical evidence, the effect of the virtual environment on its participant-players.

Across domains, researchers, engineers, and designers are faced with large volumes of data that are heterogeneous in nature - including spatial, abstract, and temporal information. There are numerous design and technical challenges when considering the unification, management, and presentation of these information types. Most research and applications have focused on display techniques for each of the information types individually, but much less in known about how to represent the relationships between information types. This research explores the perceptual and usability impacts of data representations and layout algorithms for the next-generation of integrated information spaces. We propose Information-Rich Virtual Environments (IRVEs) as a solution to challenges of integrated information spaces. In this presentation, we will demonstrate the application requirements and foundational technology of IRVEs and articulate crucial tradeoffs in IRVE information design. We will present a design space and evaluation methodology to explore the usability effects of these tradeoffs. Experimental results will be presented for a series of empirical usability evaluations that increase our understanding of how these tradeoffs can be resolved to improve user performance. Finally, we interpret the results though the models of Information Theory and Human Information Processing to derive new conclusions regarding the role of perceptual cues in determining user performance in IRVEs. These lessons are posed as a set of design guidelines to aid developers of new IRVE interfaces and specifications. / Ph. D.

Grid computing enables computers on different networks to share their resources in an organized way. Authorized users can deploy the resources as if they were in the same organization. This resource sharing environment is called a Virtual Organization (VOs). To enable an open Grid to support resource sharing between multiple heterogeneous VOs, an authorization policy management framework is required to support authorization for VOs using heterogeneous authorization systems. The challenges include dynamic Grid memberships, VO trust relationships, and heterogeneous authorization systems. / To solve these problems in a loose-coupling way, we propose a dynamic, distributive and heterogeneous authorization policy management framework. The framework is called Dynamic Policy Management Framework (DPMF). DPMF groups VOs of the same authorization systems to form a virtual cluster. Authorization policy management is divided into inter-cluster heterogeneous policy management, and intra-cluster homogeneous policy management. Inside a virtual cluster, the workloads of policy management can be distributed among the VOs according to their trust relationships. The Conflict Analysis with Partial Information (CAPI) mechanism is developed to make authorization decisions in open environments without complete policy information. A Heterogeneous Policy Management mechanism is developed for DPMF to support inter-cluster heterogeneous policy management. / Traditional authorization policy management frameworks work well in authorization for a single VO where the participating hosts agree to follow a global authorization system. However, they are not capable of authorization policy management for multiple VOs which deploys heterogeneous authorization systems. / Yu, Chiu Man. / "April 2007." / Adviser: Ng Kam Wing. / Source: Dissertation Abstracts International, Volume: 69-01, Section: B, page: 0447. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 200-206). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

The rapid growth of the internet over the past decade has provided increasing opportunities for individuals to engage in computer-mediated social interaction in virtual environments. Despite this rapid growth there has been limited research into the way people use the Internet, and the effect Internet use has on their lives (Kraut, 1996). The overall aim in the research presented in this thesis was to explore how characteristics of the individual interact with characteristics of computer-mediated communication to enable socio-emotional communication and behaviour in social text-based virtual environments. Three studies are presented. Studies One and Two are qualitative studies of social interaction in two text-based, synchronous ('real time') virtual environments: MOOs (Multi User Dimensions, Object Oriented) and Internet Relay' Chat (IRC). Grounded Theory (Glaser & Strauss, 1967) methodology was used to develop formal theories of social interaction within these environments. Stage models of virtual environment use were developed that described changes in social interaction over time. In MOOs, changes in social interaction over time reflected the process of coming to terms with what was initially viewed by users as an alternative reality. In IRC the central feature of social interaction that emerged was the perceived ease of communication. This was attributed to the effortlessness of meeting a wide range of potential communication partners in a social context where the communication itself was simplified to text only communication. The hypotheses developed from the qualitative research in Studies One and Two were tested in Study Three. This was a longitudinal study of new Internet users that examined the bi-directional effects of personality characteristics and computer-mediated communication on behaviour. Personality measures were poor predictors of time spent in ++ / both specific types of virtual environments and on-line in general. Based on the usage patterns across the three studies a decision pathway for the use of virtual environments was developed. A key finding across the studies was the potential for virtual environments to enhance psychological well-being for individuals who experience social discomfort in off-line settings. Limitations of the research were discussed and suggestions made for future research.

The purpose of this project is to develop a software framework, a 3D engine, which will generate images to be projected onto facets of a spatially immersive display (SID). The goal is to develop a software library to support the creation of images of specified 3D environments which are specific to the display geometries of a polyhedral class of SIDs. Part of this goal is developing auxiliary software to allow this library to be thoroughly tested. When properly working, the images being displayed on adjoining faces of the SID appear spatially and temporally consistent with one another, creating the illusion that the user is within a surrounding three-dimensional space.

The purpose of this project is to develop a software framework, a 3D engine, which will generate images to be projected onto facets of a spatially immersive display (SID). The goal is to develop a software library to support the creation of images of specified 3D environments which are specific to the display geometries of a polyhedral class of SIDs. Part of this goal is developing auxiliary software to allow this library to be thoroughly tested. When properly working, the images being displayed on adjoining faces of the SID appear spatially and temporally consistent with one another, creating the illusion that the user is within a surrounding three-dimensional space.