http://hdl.handle.net/11189/1830 Wed, 12 Aug 2026 10:53:21 GMT 2026-08-12T10:53:21Z http://hdl.handle.net/11189/10514 Title: A high efficiency class-E power amplifier with tuned output network Authors: Court, Evan; Balyan, Vipin Abstract: A switch-mode power amplifier (PA), like the proposed class-E renders itself capable of achieving a theoretical power conversion efficiency (PE) of 100% by ensuring specific bias and switching conditions of the active device and presenting an idealized impedance at the drain of the active device [1] [2] [3]. The design presented satisfies the zero-voltage switching (ZVS) and zero derivative voltage switching (ZVDS) conditions which are fundamental to correct class-E PA operation. The output network performs a dual function of impedance transformation to a standard 50 ohm impedance and harmonic suppression for any power being transmitted at harmonic frequencies. Mon, 01 Jan 2024 00:00:00 GMT http://hdl.handle.net/11189/10514 2024-01-01T00:00:00Z http://hdl.handle.net/11189/10513 Title: Performance assessment of steady-state voltage stability indices for parameter validation using ANFIS Authors: Adewuyi, Oludamilare Bode; Krishnarmurthy, Senthil Abstract: Precision and consistency in monitoring the voltage stability conditions of power system networks remain vital aspects of modern power system operation. Thus, this study presents a machine learning approach for comparative performance evaluation of some voltage stability indices (VSIs). Six essential power system parameters from the transmission line data and load flow solution at different real and reactive load levels are used as input information for implementing adaptive neuro-fuzzy inference system (ANFIS) models based on the subtractive clustering rules. The performance of the considered VSIs is evaluated using the mean absolute percentage error (MAPE), the Percentage Relative Root-Mean-Square Error (RRMSEp), and the linear regression based on correlation coefficient R. The IEEE 30-bus system is used as a test, and the predictive analysis results are obtained for several simulation runs for parameter tuning and model regularity. Considering the MAPE analysis, FVSI with average MAPE = 4.7429% and maximum MAPE = 6.6574% outperformed the other VSIs; average MAPE values are 5.6165% for LMN, 12.4684% for NLSI and 14.7167% for LQP. The consistency of FVSI for precise monitoring of power system voltage stability condition, compared to the other VSIs, is verified by the RRMSEp and R analysis results. Sun, 01 Jan 2023 00:00:00 GMT http://hdl.handle.net/11189/10513 2023-01-01T00:00:00Z http://hdl.handle.net/11189/10512 Title: The technopreneurial hub: an innovative entrepreneurial approach to minimise clothing and textile waste Authors: Patnaik, Sweta Abstract: The clothing and textile industry contribute over all 4% share of global greenhouse gas emissions that starts from initial raw material extraction up until the end-of-use disposal. The root cause being mass-produced fast fashion that is easily and cheaply replaced thus resulting in very large volumes of unwanted clothing that has to be dealt with effectively including the leftover fabrics and offcuts. The "Sustainability Clothing and Textile Project” took shape in 2019 where the students from a University of Technology based in South Africa were tasked to use off cut (leftover fabric edges and trims) fabrics from finished garments in the laboratory that would have otherwise been thrown away as waste and ended on the landfill sites. The project objectives were for the learners to ‘think out of the box’, be innovative and use critical thinking skills to create meaningful products while introducing the concept of sustainability and technopreneurial skills. Technopreneurship refers to the practice of combining technology and entrepreneurship, where individuals or organizations leverage technological innovations and advancements to create, develop, and manage new ventures or business opportunities. Technopreneurs are individuals who identify and capitalize on technology-based business ideas, utilizing their entrepreneurial skills to bring these ideas to fruition. Through this research we focus on providing an entrepreneurial support, addressing job creation and curriculum development. The research will also address the societal challenges in South Africa for the vulnerable sections of the society for whom these opportunities are limited and at the same time generating new entrepreneurs or increasing accessibility to the job market, creating hope for the future. Mon, 01 Jan 2024 00:00:00 GMT http://hdl.handle.net/11189/10512 2024-01-01T00:00:00Z http://hdl.handle.net/11189/10510 Title: The role of digital technologies in promoting sustainable and human-centric waste management practices: a review of current practices and future directions Authors: Sogaxa, Athenkosi; Mphako, Nontlahla; Simpeh, Eric Kwame Abstract: Purpose of this paper: The purpose of this literature review study is to look at the role of digital technology in supporting sustainable and human-centered waste management practices within the context of Construction 5.0 (C5.0). A diverse range of available waste management methods may need to be clarified or more complex to use, particularly with the sustainable development goal. Design/methodology/approach This paper uses secondary data to cross-examine existing practices and proposes a conceptual model for resource efficiency, reduce waste, and promote environmental sustainability. The data synthesis and analysis were carried out systematically using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework. Findings The findings from the systematic review revealed that contractors adopt awareness, waste management-related policy, legislation and regulation, and adoption of Building Information Modelling (BIM) to monitor waste. Furthermore, educating the workforce to effectively manage waste on construction sites and optimizing construction resources are important in achieving sustainable waste management practices. Research limitations/implications (if applicable) This study focuses on reviewing existing literature on construction waste management practices. Newly developing technologies not included in the study may present additional opportunities and difficulties that need to be investigated. Practical implications (if applicable) The outcomes of this study will help academics improve their understanding of key management practices for decreasing on-site construction waste through sustainable and human-centered waste management practices within the context of Construction 5.0 (C5.0). What is original/value of paper. This paper provides the contributors to successful contractors’ waste management approaches in South Africa through the enhancement of technology to achieve sustainable and human-centered waste management practices. Mon, 01 Jan 2024 00:00:00 GMT http://hdl.handle.net/11189/10510 2024-01-01T00:00:00Z