Most interaction with computers today takes place in a two dimensional environment. Even when using three dimensional graphics applications, input is often still restricted to two dimensions. Many believe that the use of three dimensional input devices will alleviate this restriction and allow for a much more natural human-machine dialog. This thesis seeks to establish how factors dealing with visual feedback and task structure affect the ability to perform interactive tasks in a three dimensional virtual environment. The factors investigated were stereoscopic vision, motion parallax, stimulus arrangement and stimulus complexity. Four tasks were studied. These tasks were: point location, docking, line tracing and curve tracing. All the tasks used a six degree of freedom input device to control a pointer in a three dimensional virtual environment. Four experiments corresponding to the four tasks were conducted to investigate these factors. Among other things the results showed the following. Stereoscopic vision provided a strong benefit to positioning-based tasks, but this benefit was weakened in the case of tracing tasks. Motion parallax via head-tracking often had no effect upon task performance and where an effect was found it was often detrimental. The position of stimuli influenced performance across all of the tasks. The orientation of stimuli influenced performance in the task in which it was varied. / Science, Faculty of / Computer Science, Department of / Graduate

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This study used a standardized evaluation to compare two direct manipulation graphics interfaces. The Interfaces investigated were (1) object-oriented (vector) graphics and (2) bit-mapped graphics (object-oriented graphics interfaces are not to be confused with object-oriented programming or object-oriented data bases). Experienced and novice subjects performed objectively derived benchmark tasks appropriate for two-dimensional graphics packages. Both performance and preference data were collected. Task completion time, aborted attempts, learning effects, and errors constituted the performance measures. For the preference data, subjects completed questionnaires to rate the interfaces on both an absolute and a relative basis. Results indicate that the object-oriented graphics interface is superior to the bit-mapped interface. Both the performance and preference measures indicate that the object-oriented interface is better suited for manipulation of graphics. / Master of Science

Computer-aided process planning is an essential interface between computer-aided design and computer-aided manufacturing. In this thesis, a computer-aided process planning system - TIPPS is developed. A CAD design model is used for direct input in the TIPPS system. A boundary internal model of the engineering part drawing is displayed on a CRT screen, and using an interactive procedure, surface which require machining can be marked. A backward planning scheme searches a process knowledge database to find a sequence of manufacturing processes which can achieve the design specification. The process knowledge database consists of process description statements. A process description statement (mathematical terms are used) represents the capabilities of a single process. TIPPS also selects process parameters - feed and cutting speed automatically. TIPPS provides: 1) direct CAD interface, 2) external process capability description language, 3) modular structure, and 4) interactive surface identification. Various approaches used in designing and process planning are discussed. A review of CAD, process engineering, planning decision methods and current process planning systems is included. / Ph. D.

The Dialogue Management System (DMS), the setting for this research, is a system for designing, implementing, testing, and modifying interactive human-computer systems. As in the early stages of software engineering development, current approaches to human-computer interface design are ad hoc, unstructured, and incomplete. The primary goal of this research has been to develop a structural, descriptive, language-oriented model of human-computer interaction, based on a theory of human-computer interaction. This model is a design and implementation model, serving as the framework for a dialogue engineering methodology for human-computer interface design and interactive tools for human-computer interface implementation. This research has five general task areas, each building on the previous task. The theory of human-computer interaction is a characterization of the inherent properties of human-computer interaction. Based on observations of humans communicating with computers using a variety of interface types, it addresses the fundamental question of what happens when humans interact with computers. Formalization of the theory has led to a muIti-dimensional dialogue transaction model, which encompasses the set of dialogue components and relationships among them. The model is based on three traditional levels of language: semantic, syntactic, and lexical. Its dimensions allow tailoring of an interface to specific states of the dialogue, based on the sequence of events that might occur during human-computer interaction. This model has two major manifestations: a dialogue engineering methodology and a set of interactive dialogue implementation tools. The dialogue engineering methodology consists of a set of procedures and a specification notation for the design of human-computer interfaces. The interactive dialogue implementation tools of AIDE provide automated support for implementing human-computer interfaces. The AIDE interface is based on a "what you see is what you get" concept, allowing the dialogue author to implement interfaces without writing programs. Finally, an evaluation of work has been conducted to determine its efficacy and usefulness in developing human-computer interfaces. A group of subject dialogue authors using AIDE created and modified a prespecified interface in a mean time of just over one hour, while a group of subject application programmers averaged nearly four hours to program the identical interface. Theories, models, methodologies, and tools such as those addressed by this research promise to contribute greatly to the ease of production and evaluation of human-computer interfaces. / Ph. D.

Thesis: M.S., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 1981 / Bibliography: leaves 59-60. / by Daniel Goodman Shapiro. / M.S. / M.S. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science

The purpose of this project to develope a network syslog monitoring system to monitor network devices like printers, switches, etc. and to help the network technical help desk personnel to handle issues promptly and effectively based on the syslog messages captured by the syslog server.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2007. / Next-generation nanosatellites are becoming a very cost effective solution to gain access to space. Modern manufacturing technology together with low power low cost devices makes the development of nanosatellites, using standard industrial components, very attractive. A typical nanosatellite will have only one microprocessor, capable of performing all the computing tasks onboard the satellite - housekeeping, AODC (Attitude and Orbit Control) and instructing the different payloads aboard the satellite. One of the major requirements was to choose a processor from a dominant manufacturer in the market that will still be available for future satellite missions. Just as the 8051 dominated the 8-bit market, the ARM7 processor is fast becoming a market leader in the segment for 16-bit applications. ARM processors has also been used much in handheld devices in recent years - which emphasize the low power requirements and stability of these processors in embedded applications. This thesis investigates the different processors that are currently available. A complete system design is done, taking into account all the different modules needed onboard a very small Low Earth Orbit (LEO) satellite. Finally, some test results are given showing how this system can be reliably used onboard a nanosatellite in future.

With the increasing demand for online learning, well-designed computer online learning resources are indispensable. User interfaces evaluation has become a critical quality attribute of interactive software intended to meet the requirements of the user groups. It is this aspect of adaptations that make them critical for the study of evaluation of user interfaces. This study describes a preliminary evaluation of the user interface design of a new online learning resource (Open Learning System). The main objectives of the study are to investigate the effect of the interaction on the user (usability, efficiency, effectiveness and satisfaction), to assess the extent of the system (resource) functionality and to identify specific problems in the design (aspects of design that cause unexpected results or confusion). This will form part of iterative design and testing process of the new interface, which seeks to evaluate the success of the interface within the framework of the fundamental HCI principles under guidelines of the constructivists learning approach. The Open Learning System (OLS) is grounded on the constructivist-based learning approach. The underlying philosophy of the system assumes when learners are engaged in a social learning context, they actively construct knowledge, therefore the resource is considered as a tool to support learning and not an end in itself. By so doing it is geared to provide greater access to information, support Computer-Mediated Communication (CMC) using tools such as e-mail, chat and discussion foruI? and creating context for learners' work and peer review. A theoretical framework for evaluating the OLS was developed and proposed which comprised of the constructivist epistemology, Rich Environment for Active Learning (REAL), the User Centred Design (UCD) approach and the Human Computer Interface (HCI) design principles. This integrated theoretical framework has been referred to as 'Designing-by-Constructivism' model. The study investigates the use of the OLS by two sets of users: staff members (module creators) and learners (module consumers). In view of the fact that the data collected is qualitative, the approach assumes the use of semi-structured questionnaires, evaluation matrix and interviews. The information/feedback gathered will assist the developers to do preliminary reviews. The study will also be useful to academics pursuing more HCI issues or those with an interest in developing learning resources. The main elements of the 'Designing-by-Constructivism' model were present in the resource. The results analysis indicates that the resource supports collaborative learning and the use of authentic activities in learning. This serves as an intrinsic motivation to most of the users. The results also show a high degree of user satisfaction and appreciation of OLS resource. Largely, the participants are satisfied that the overall OLS design met their needs. The major contribution being, "OLS is interactive and user friendly". However, some users have expressed the desire to have more tools incorporated into the resource, while others have expressed concern about difficulties in logging into the system. / Thesis (M.Sc.)-University of Natal, Durban, 2003.