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This thesis investigates the development of a low cost, component based facial virtual conferencing system. The design is decomposed into an encoding phase and a decoding phase, which communicate with each other via a network connection. The encoding phase is composed of three components: model acquisition (which handles avatar generation), pose estimation and expression analysis. Audio is not considered part of the encoding and decoding process, and as such is not evaluated. The model acquisition component is implemented using a visual hull reconstruction algorithm that is able to reconstruct real-world objects using only sets of images of the object as input. The object to be reconstructed is assumed to lie in a bounding volume of voxels. The reconstruction process involves the following stages: - Space carving for basic shape extraction; - Isosurface extraction to remove voxels not part of the surface of the reconstruction; - Mesh connection to generate a closed, connected polyhedral mesh; - Texture generation. Texturing is achieved by Gouraud shading the reconstruction with a vertex colour map; - Mesh decimation to simplify the object. The original algorithm has complexity O(n), but suffers from an inability to reconstruct concave surfaces that do not form part of the visual hull of the object. A novel extension to this algorithm based on Normalised Cross Correlation (NCC) is proposed to overcome this problem. An extension to speed up traditional NCC evaluations is proposed which reduces the NCC search space from a 2D search problem down to a single evaluation. Pose estimation and expression analysis are performed by tracking six fiducial points on the face of a subject. A tracking algorithm is developed that uses Normalised Cross Correlation to facilitate robust tracking that is invariant to changing lighting conditions, rotations and scaling. Pose estimation involves the recovery of the head position and orientation through the tracking of the triangle formed by the subject's eyebrows and nose tip. A rule-based evaluation of points that are tracked around the subject's mouth forms the basis of the expression analysis. A user assisted feedback loop and caching mechanism is used to overcome tracking errors due to fast motion or occlusions. The NCC tracker is shown to achieve a tracking performance of 10 fps when tracking the six fiducial points. The decoding phase is divided into 3 tasks, namely: avatar movement, expression generation and expression management. Avatar movement is implemented using the base VR system. Expression generation is facilitated using a Vertex Interpolation Deformation method. A weighting system is proposed for expression management. Its function is to gradually transform from one expression to the next. The use of the vertex interpolation method allows real-time deformations of the avatar representation, achieving 16 fps when applied to a model consisting of 7500 vertices. An Expression Parameter Lookup Table (EPLT) facilitates an independent mapping between the two phases. It defines a list of generic expressions that are known to the system and associates an Expression ID with each one. For each generic expression, it relates the expression analysis rules for any subject with the expression generation parameters for any avatar model. The result is that facial expression replication between any subject and avatar combination can be performed by transferring only the Expression ID from the encoder application to the decoder application. The ideas developed in the thesis are demonstrated in an implementation using the CoRgi Virtual Reality system. It is shown that the virtual-conferencing application based on this design requires only a bandwidth of 2 Kbps. / Adobe Acrobat Pro 9.4.6 / Adobe Acrobat 9.46 Paper Capture Plug-in

Please read the abstract in the section 00front of this document / Dissertation (MSc (Computer Science))--University of Pretoria, 2007. / Computer Science / MSc / unrestricted

Please read the abstract in the section 00front of this document / Dissertation (MSc (Computer Science))--University of Pretoria, 2007. / Computer Science / unrestricted

Chattbottar har den senaste tiden, genom snabbmeddelandetjänsternas stora tillväxt, blivitallt populärare. Chattbottar används idag till allt från automatisk kundtjänst tillnöjesinriktade ändamål. Numera finns flera olika ramverk för att skapa chattbottar med olikaegenskaper.Syftet med detta arbete var att undersöka hur chattbottar kan integreras i existerandesnabbmeddelandetjänster på ett underhållbart och flexibelt sätt. En prototyplösning förmeddelandetjänsten Briteback skapades med opensource-ramverken React, Node.js och Deepstream. Rapporten beskriver för- och nackdelar med den valda lösningen specielltavseende flexibilitet och underhåll.

Personal Digital Assistants (PDAs) have recently become a popular component in mobile robots. This compact processing device with its touch screen, variety of built-in features, wireless technologies and affordability can perform various roles within a robotic system. Applications include low-cost prototype development, rapid prototyping, low-cost humanoid robots, robot control, robot vision systems, algorithm development, human-robot interaction, mobile user interfaces as well as wireless robot communication schemes. Limits on processing power, memory, battery life and screen size impact the usefulness of a PDA in some applications. In addition various implementation strategies exist, each with its own strengths and weaknesses. No comparison of the advantages and disadvantages of the different strategies and resulting architectures exist. This makes it difficult for designers to decide on the best use of a PDA within their mobile robot system. This dissertation examines and compares the available mobile robot architectures. A thorough literature study identifies robot projects using a PDA and examines how the designs incorporate a PDA and what purpose it fulfils within the system it forms part of. The dissertation categorises the architectures according to the role of the PDA within the robot system. The hypothesis is made that using a distributed control system architecture makes optimal use of the rich feature set gained from including a PDA in a robot system’s design and simultaneously overcomes the device’s inherent shortcomings. This architecture is developed into a novel distributed intelligence framework that is supported by a hybrid communications architecture, using two wireless connection schemes. A prototype implementation illustrates the framework and communications architecture in action. Various performance measurements are taken in a test scenario for an office robot. The results indicate that the proposed framework does deliver performance gains and is a viable alternative for future projects in this area.

New innovative products are being designed while the user interface of existing products is constantly being revamped to give them a new look. All this is an effort to bring a satisfactory interacting experience for the user. However, in most cases users do not feel that they experience that benefit. The introduction of a new product, or the enhancement of the functionality and user interface of an existing product, often faces criticism and brings resistance to the acceptance and usage of the product by the users. Therefore, the change in user interface or introduction of new products does not only affect the business processes but also the lifestyles of the users, as well as their overall user experience. One of the most important components for the success of any product is a positive user experience. User experience refers to the subjective feeling of the user that results from their interaction or intention to interact with a product in order to perform a specific task in a specific environment. When the user interface and functionality of a product match the expectations of the users and make the users effective and efficient, feel safe and attain some level of self-worth from using or possessing the product, their interaction with the product becomes more satisfactory. User experience practitioners are in agreement that a change to the user interface influences the user experience of the people when interacting with the product; hence it affects change in the user experience of the people. A vast body of literature exists on the methods for evaluating user experience as well as on the principles that are aimed at guiding the design of products for a positive user experience. However, there is a lack of a means to manage this change in user experience that results from the changes in the features of the user interface or the product functionalities. This inadequacy opens up the potential for integrating change management principles in order to manage user experience. However, existing change management principles do not address the user experience aspects when managing change. Following the above premise, this study focused on the development of a model for managing user experience: the User Experience Management Model (UXM2). The UXM2 infers its components from the disciplines of user experience and change management. Its uniqueness is seated in its people-centred approach that aims to effect a free-will change in the individuals towards a long-term positive user experience. The proposed model further aims to promote the voluntary acceptance of a product, which is contrary to the mandatory change that is guided by the policies of the organization, as discussed in the study. The UXM2 was developed from a thorough argumentation of literature on user experience and change management. The components that were required for development of the model were identified from literature, and were evaluated for their relevance by means of academic publications in subject domain international conferences. The academic publications underwent double-blind peer review with subject domain experts. The model was evaluated for its relevance and potential applicability through interviews and discussions with subject domain experts. The subject domain experts consist of user experience practitioners and academic professionals in the domain of HCI. The subject domain experts also evaluated the model by means of an evaluation tool comprising of a Likert scale rating of the proposed components and related activities for managing user experience. The target users of the UXM2 are user experience practitioners and product developers who aim to promote a sustainable long-term positive user experience for the people interacting with their products. The UXM2 is aimed at being used for the design of products that are meant for institutional use, personal use, mandatory use and optional use. It is believed that adoption of the UXM2 will promote acceptance of the product by users, with an associated sustainable positive long-term user experience.

As user interfaces become more powerful and easier to use they are often harder to design and implement. This has caused a great demand for interface tools. While existing tools ease interface creation, they typically do not provide mechanisms to simplify application development and are too low-level. Furthermore, existing tools do not provide effective mechanisms to port interactive applications across user interfaces. While some tools provide limited mechanisms to port applications across user interfaces which belong to the same class (e.g., the class of all standard graphical direct-manipulation user interfaces), very few can provide the ability to port applications across different interface classes (e.g., command-line, hypermedia, speech recognition and voice synthesis, virtual reality, etc.). With my approach, the programmer uses an abstract model to describe the structure of the application including the information that the application must exchange with the user, rather than describing a user interface which realizes these characteristics. By specifying application semantics at a very high level of abstraction it is possible to obtain a much greater separation between the application and the user interface. Consequently, the resulting applications can be ported not only across user interfaces which belong to a common interface class, but across interfaces which belong to distinct classes. This can be realized through simple recompilation - source code does not have to be modified. NAAG (Not Another Application Generator), a tool which embodies these ideas, enables programmers to create interactive applications with minimal effort. An application is modelled as a set of operations which manipulate objects belonging to user-defined object classes. The input to NAAG is a source program which describes classes, operations and their inputs and outputs, and the organization of operations within the application. Classes and operations are implemented as data structures and functions in a conventional programming language such as C. This model simplifies not only the specification and generation of the user interface, but the design and implementation of the underlying application. NAAG utilizes existing technology such as macro-preprocessors, compilers, make programs, and low-level interface tools, to reduce the programming task. An application that is modified by adding, removing, or reorganizing artifacts (classes, operations, and menus), can be regenerated with a single command. Traditionally, software maintenance has been a very difficult task as well. Due to the use of a simple abstract model, NAAG applications are also easier to maintain. Furthermore, this approach encourages software reuse: applications consisting of arbitrary collections of original and pre-existing artifacts can be composed easily; functions which implement abstract operations are independent of both, user interface aspects, and the context in which they are employed. Application development is further simplified in the following ways: the programmer describes the semantics of the user interface - a conventional explicit specification is not required; output primitives are defined in an interface-independent manner; many programming tasks such as resource management, event processing, and communication, are either handled directly by the tool or else simplified greatly for the programmer. NAAG is currently used by the members of the Laboratory for Computational Vision at the University of British Columbia to maintain a sophisticated image processing system. / Science, Faculty of / Computer Science, Department of / Graduate

Weather data is important for almost everyone today. Thedaily weather report, home thermometers, and a lot of otherthings affect our every day life. In order to develop betterand more efficient equipment, tools and algorithms, thepeople working with this data need to be able to access it inan easily accessible and easy to read format. In thisresearch, methods of visualizing data on mobile platformsare evaluated based on what researchers in the field wants,since their respective fields might want to use very specificvisualizations. The implementability of these visualizationsare then evaluated, based on the implementations madethroughout this paper. The results show that the researchersknow what they want, and that what they want isimplementable on mobile platforms given some limitationscaused by performance.

The objectives of the research were to determine whether there is a preferred device in the home environment that the consumer would perceive to be easy to use, offer a sense of security and allow the seamless purchase of commodity items. The research involved interviews with leading managers in large corporations that influence the development of products used in the home environment as well as a survey to a controlled group of consumer electronic experts. The research findings show that although there is much hype about the future of certain technology devices for use in the home environment, the consumer is interested in an easy to use technology that offers seamless connectivity in a secure environment with trusted service providers. Lastly, the findings established that further in depth research is required on the impact of the new wireless networks and mobile connectivity. / Mrs. Nikki Kettles