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Thesis (MComm (Economics)--Nelson Mandela Metropolitan University, 2011. / ENGLISH ABSTRACT: Renewable energy technology has received much attention over recent years. The depletion of known fossil fuel reserves and the volatility of international fuel prices require that society looks beyond the current coal-dominated electricity generation methods. Wind energy is an internationally well-established technology with large markets in major countries around the world, such as the USA and Germany. South Africa has the potential to generate large amounts of electricity from the wind because of the strength of the country’s wind resource. The long coast line and open areas are ideal for the exploitation of wind energy. / Sponsored by the Centre for Renewable and Sustainable Energy Studies

<p> This thesis investigates the impact of gamification on student motivation and learning in several introductory computer science educational activities. The use of game design techniques in education offers the potential to make learning more motivating and more enjoyable for students. However, the design, implementation, and evaluation of game elements that actually realize this promise remains a largely unmet challenge. This research examines whether the introduction of game elements into curriculum positively impacts student motivation and intended learning outcomes for entry-level computer science education in four settings that apply similar game design techniques in different introductory computer science educational settings. The results of these studies are evaluated using mixed methods to compare the effects of game elements on student motivation and learning in both formal and non-formal learning environments.</p>

A new process of combining gas injection with compression moulding was developed and studied in this research work. The process is called Gas Assisted Compression Moulding (or GasComp). The principle is based on the injection of nitrogen gas during a conventional compression moulding cycle. The flow of the material due to the compressive force of the press is assisted by the injection of gas into the centre of the molten material. The gas assists in the flow by coring out the material, reducing the weight by up to 45 percent and increasing the dimensional stability of the component. Novel glass matt thermoplastic mould tools were designed and developed during the course of the research program for use with the process. These designs were of a flash compression mould tool design with a horizontal clamping face, rather than the conventional positive plug compression mould tool with a vertical shear edge. This created a fixed volume mould tool, which when used in conjunction with a short shot of material, would allow the gas to flow the material to fill the remaining volume. Several materials were investigated for their suitability with the process. Their characterisation showed that they contained different glass fibre contents and architectures. A material with a short, dispersed glass fibre content of 11 percent proved to consistently contain a significant gas cavity. The glass architecture proved to be the most significant contributing factor in the creation of a successful gas cavity. The most significant processing parameter in the creation of a large volume cavity proved to be the gas injection delay time. The gas pressure and gas ramp time affected the cavity shape, length and extent of gas fingering. The shrinkage was reduced in the presence of a gas cavity, along with the visible reduction of sink marks. The presence of other moulding features, such as hesitation marks, gas packing and the change in fibre orientation were also discussed.

A novel adsorption cycle in which enhanced heat transfer between the adsorbent and external heat sinks and sources is achieved by forced convection of refrigerant gas through the adsorbent bed is presented This cycle is further developed by the use of inert beds to store the heat of desorption and sensible heat between phases. The performance and utility of such a cycle will depend on the heat transfer coefficients and pressure drops that result when the refrigerant gas is circulated through the beds The heat transfer and pressure drop characteristics of a bed of granular active carbon were investigated using argon, carbon dioxide and ammonia. Equipment was designed and built to pass a stream of gas through a bed at a controlled rate, pressure and temperature. The pressure drop characteristic was found to conform to Ergun equation and the constants for the application of that relation to a commonly available granular active carbon established. A mathematical model based on a finite difference technique was created and used to predict the progress of a temperature front in the bed and derive the heat transfer characteristics from experimental data. Heat transfer coefficients measured with argon and ammonia appeared inconsistent with each other and after investigations of the data and comparison with established correlations were made it was concluded that carbon during the argon experiments had been contaminated. The heat transfer results with ammonia and carbon were compared with a modified version of the Colburn analogy between heat transfer and pressure loss. A correlation between the Nusselt number and Reynolds number for design purposes was established.

Generating high-fidelity images in real-time at reasonable frame rates, still remains one of the main challenges in computer graphics. Furthermore, visuals remain only one of the multiple sensory cues that are required to be delivered simultaneously in a multi-sensory virtual environment. The most frequently used sense, besides vision, in virtual environments and entertainment, is audio. While the rendering community focuses on solving the rendering equation more quickly using various algorithmic and hardware improvements, the exploitation of human limitations to assist in this process remain largely unexplored. Many findings in the research literature prove the existence of physical and psychological limitations of humans, including attentional, perceptual and limitations of the Human Sensory System (HSS). Knowledge of the Human Visual System (HVS) may be exploited in computer graphics to significantly reduce rendering times without the viewer being aware of any resultant image quality difference. Furthermore, cross-modal effects, that is the influence of one sensory input on another, for example sound and visuals, have also recently been shown to have a substantial impact on viewer perception of virtual environment. In this thesis, auditory-visual cross-modal interaction research findings have been investigated and adapted to graphics rendering purposes. The results from five psychophysical experiments, involving 233 participants, showed that, even in the realm of computer graphics, there is a strong relationship between vision and audition in both spatial and temporal domains. The first experiment, investigating the auditory-visual cross-modal interaction within spatial domain, showed that unrelated sound effects reduce perceived rendering quality threshold. In the following experiments, the effect of audio on temporal visual perception was investigated. The results obtained indicate that audio with certain beat rates can be used in order to reduce the amount of rendering required to achieve a perceptual high quality. Furthermore, introducing the sound effect of footsteps to walking animations increased the visual smoothness perception. These results suggest that for certain conditions the number of frames that need to be rendered each second can be reduced, saving valuable computation time, without the viewer being aware of this reduction. This is another step towards a comprehensive understanding of auditory-visual cross-modal interaction and its use in high-fidelity interactive multi-sensory virtual environments.

<p> Professional Development for technology integration into the elementary curriculum has been a costly and frequently ineffective endeavor. The idea for the Tech Buddy model came from this frustration. Teaming a teacher who had high comfort and self-efficacy levels with technology, however who still had much to learn, together with a teacher who was willing to learn, but had low comfort and self-efficacy levels seemed natural.</p><p> The study consisted of 13 educators and one Administrative Intern from the school of study. The study paired a mentor who had a high level of comfort and self-efficacy with ICT integration with a mentee who had a low level of comfort and self-efficacy with ICT integration as measured by a pre-study self-assessment. The pairs were formed using three types; two were same grade level pairs, two were adjacent grade level pairs, and two were nonadjacent grade level pairs. All participants attended one half-day release time per quarter, one two-hour planning time per quarter and one evening stipend time per semester. Three of the six pairs began the study using iPads. Three of the six pairs began the study using Chromebooks. Midway through the study, the pairs all switched in order to use the other devices. The researcher also conducted interviews of each participant midway and at the end of the study. At the conclusion of the study, each participant again took the self-assessment in an effort to determine if the study was affective in increasing comfort and self-efficacy levels with ICT integration into the curriculum. The conclusion of the self-assessment indicated an increase in comfort level and self-efficacy in all participants except one pairing. The results were mostly positive and expected, however, one of the pairing did not show anticipated growth in all areas of self-assessment.</p><p> The conclusion of the study indicated the Tech Buddy program is a viable option for increasing comfort and self-efficacy levels of ICT integration into the elementary curriculum. The use of one particular device over another did not seem of concern. Application of the model should pay particular attention to how each mentor perceives his or her role as mentor.</p>

<p> Providing students with necessary intervention in the instruction of mathematics can be accomplished through the use of digital resources. Schools reaching a one-to-one (one device for every student) status have the ability to implement a digital intervention on a broad scale. For the purpose of this study, mixed methods research afforded an in-depth investigation into the impact of Khan Academy (digital intervention) embedded in a one-to-one program on student achievement, student perseverance with math, and teacher pedagogy within rural schools. The theoretical framework of educational technology integration known as Theoretical, Pedagogical, and Content Knowledge (TPACK) was woven into this study to answer the guiding research questions. While using Khan Academy in a one-to-one setting, participating students were tested twice a year utilizing the Measurement of Academic Progress (MAP) testing procedure provided by the Northwest Evaluation Association (NWEA). The testing data provided quantitative data for the study. In addition, interviews of teachers and administrators were conducted to reveal themes related to teacher pedagogy and student perseverance with mathematical problems. An analysis of MAP scores revealed that 9th- and 10th-grade high school students utilizing Khan Academy in a one-to-one program demonstrated significantly more growth when compared to national norms. The study involved 227 9th-grade and 114 10th-grade students from three rural high schools in the Pacific Northwest. Results from an analysis of means illustrated that each grade level demonstrated significantly greater growth when compared to national norms. When examined at the school level, each of the three sites once again exceeded growth norms. Further analysis of the interviews revealed a pedagogical shift directly related to the use of Khan Academy embedded in a one-to-one program. Themes related to the success of the program include the ability of Khan Academy to fill individual gaps and practice skills to mastery, the importance of student and teacher buy-in, and the ability for students to have daily, individual access to devices. Furthermore, the interviews revealed teachers and principals did not agree on whether Khan Academy impacts student perseverance; however, a theme related to Khan Academy&rsquo;s ability to impact confidence with math did emerge. This study fills gaps in the existing literature regarding the academic and pedagogical impact of Khan Academy on teaching and learning. In addition, this study addresses a gap in the literature regarding rural schools&rsquo; use of a digital mathematical intervention program as a means of blended learning. Implications for educational policy can result from this study given the current political climate surrounding one-to-one and blended learning deployments. This study demonstrates that when one-to-one deployments are paired with the use of Khan Academy, student achievement can be positively impacted.</p>

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The primary outcome of this research project is the development of a methodology enabling fast automated early-stage power and energy analysis of configurable processors for system-on-chip platforms. Such capability is essential to the process of selecting energy efficient processors during design-space exploration, when potential savings are highest. This has been achieved by developing dynamic and static energy consumption models for the constituent blocks within the processors. Several optimisations have been identified, specifically targeting the most significant blocks in terms of energy consumption. Instruction encoding mechanism reduces both the energy and area requirements of the instruction cache; modifications to the multiplier unit reduce energy consumption during inactive cycles. Both techniques are demonstrated to offer substantial energy savings. The aforementioned techniques have undergone detailed evaluation and, based on the positive outcomes obtained, have been incorporated into Cascade, a system-on-chip coprocessor synthesis tool developed by Critical Blue, to provide automated analysis and optimisation of processor energy requirements. This thesis details the process of identifying and examining each method, along with the results obtained. Finally, a case study demonstrates the benefits of the developed functionality, from the perspective of someone using Cascade to automate the creation of an energy-efficient configurable processor for system-on-chip platforms.