Graduation - 2024 - December (Open Access)
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- ItemPermanent Deformation behaviour of Open-Graded Bitumen Rubber Asphalt using the Model Mobile Load Simulator (MMLS3)(Stellenbosch University, 2024-12) Kasozi, Adam Matovu; Goosen, Elaine Simone; Jenkins, Kim Jonathan; Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering.Permanent deformation (rutting) has been at the centre of many pavement research projects as one of the major pavement distresses. With road transport providing a cheap and more accessible trade outlet than rail transport, pavements in South Africa have become more susceptible to permanent deformation. This has, therefore, led to different innovations regarding mix designs and binder modifications to try to combat this distress mechanism. This study covers the resistance of Bitumen Rubber Asphalt Open-Graded (BRAOG) mixes and the permanent deformation under Model Mobile Load Simulator (MMLS) wet trafficking. Bitumen rubber has been extensively used to surface heavily trafficked pavements in South Africa. The MMLS acts as the accelerated pavement tester while the BRAOG cores are immersed in hot water at 50 °C. This helps to simulate the sub-tropical and humid climatic regions. The bitumen rubber binder (A-R2) is isolated and exposed to a series of rheological tests using the Bending Beam Rheometer (BBR), Dynamic Shear Rheometer (DSR) and Rolling Thin Film Oven (RTFO). The Multiple Stress Creep Recovery (MSCR) hightemperature test evaluates the binder's response to permanent deformation. The MMLS results show that the exponential smoothing technique provides a more accurate rut profile than the conventional 3-point moving average smoothing technique. From the binder rheology, the rubber modification provided an increased elastic behaviour at high temperatures. In conclusion, the mixes deformed more than the acceptable 2 mm rutting limit specified in the MMLS testing protocols, but the binder played a crucial role in the resistance to rutting and moisture damage of the BRAOG mixes. It is recommended that more research is done to develop and expand the specifications for modified binders and MMLS rutting empirical protocols.
- ItemA framework combining quantitative analytical methods to detect anomalies in financial statements of organisations(Stellenbosch University, 2024-12) Kapenda, Deborah; Vlok, P. J.; Schutte, C. L. S.; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.This thesis develops the Annual Financial Statement Risk Alert Signal (AFS RAS) framework to detect financial statement fraud and anomalies, integrating the Altman Z–Score, Beneish M–Score, and Benford’s Law. The framework aims to identify fraudulent activities within organisations by assessing financial health and detecting anomalies in reported data. The thesis evaluates a selection of major corporations across various industries in the United States of America, highlighting the effectiveness of each method in detecting potential fraud. The Altman Z–Score provides insights into financial distress, the Beneish M–Score identifies possible earnings manipulation, and Benford’s Law detects anomalies in numerical data. The results indicate that the framework achieves a True Positive Rate (TPR) of 80%, successfully identifying 20 out of 25 fraudulent financial statements, with a False Positive Rate (FPR) of 20%. The analysis shows that revenue manipulation is the most common type of fraud, followed by earnings manipulation and accounting issues. While the AFS RAS framework demonstrates strong potential in fraud detection, further refinement is needed to reduce false positives and enhance accuracy. This thesis highlights the importance of comprehensive financial analysis in improving fraud prevention strategies and safeguarding organisational integrity. Future research should focus on integrating additional machine learning techniques and expanding the dataset to include broader data sources and international contexts to enhance the framework’s efficacy further.
- ItemExpansion of photovoltaic module production in South Africa(Stellenbosch University, 2024-12) Kanhukamwe, Tafadzwa Nathan; Zincume, Philani Nduna; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.Expanding photovoltaic module production in South Africa offers a unique opportunity to diversify the nation's energy sources and transition from reliance on fossil fuels to renewable energy. This study seeks to create a framework that supports the growth of the PV module production industry within the unique South African context. By utilizing engineering management principles with economic decision-making and technical evaluations, this research highlights the specific challenges that South Africa's PV module production industry faces and provides actionable solutions. To find gaps in the body of knowledge related PV module production, this study starts with a systematic literature review. The review evaluates the global dynamics as well as some of the concerns and challenges facing the industry. This is followed by secondary data evaluations on global trends in the PV module industry and the emerging market demand in South Africa. Cost considerations were also discussed to assess the viability and cost-effectiveness of investing in this value chain. A framework was developed using the systems thinking approach, and then validated through valuable feedback from industry stakeholders/subject matter experts. The findings emphasize the importance of practical solutions that consider local market dynamics, policies, regulations, financial support mechanisms, infrastructure requirements, and technological advancements needed. By offering actionable insights, this research intends to contribute meaningfully to the sustainable development of South Africa's PV production industry, ultimately aiding the country's shift towards a more resilient and sustainable energy future.
- ItemThe Technology Adoption Propensity of Professionals and Companies in the Construction Industry(Stellenbosch University, 2024-12) Jurgens, Christiaan Johannes; Wium, Jan Andries; Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering.The construction industry is a strategically vital sector, but it has many concerns. Notably, some of these concerns are related to its low technology adoption. Technology adoption propensity influences technology adoption behaviour. The construction industry’s technology adoption propensity (i.e., its willingness to adopt new technologies) is therefore of key importance to its future success. This dissertation aims to quantify the technology adoption propensity of professionals and companies in the construction industry. It uses diffusion research to investigate the construction industry’s “resistance to change.” The diffusion of innovations theory, developed by E.M. Rogers in 1962, is selected as its foundational theory. The research design of this dissertation is characterised by a mixed-methods methodology using both positivist and interpretivist philosophies. The collected data are used to evaluate propositions related to its foundational theory. Validation of the findings is undertaken throughout the dissertation. This dissertation includes an examination of existing relevant international and South African literature to validate its original contributions, a review of two selected case studies, and a review of some influential books. In addition, it develops the Simple adopter categories through modification of the standardised adopter categories as published by E.M. Rogers in 1958. The dissertation then proceeds with the development, execution, and analysis of a technology adoption propensity industry survey. This is done via a self-reported questionnaire to gather primary data from registered and candidate professionals in the South African built environment. Despite being limited to South Africa, the survey results are shown to have international applicability due to the shared challenges experienced by the South African construction industry and its international counterparts. The industry survey results classify construction industry professionals as early majority technology adopters who tend to adopt new technologies slightly faster than the average person. Construction industry companies are shown to be balanced technology adopters, positioning between the early majority adopter and late majority adopter categories. They tend to adopt technology products at a rate as expected/predicted by the diffusion of innovations theory. In addition, this dissertation develops four possible future technology adoption propensity scenarios for the construction industry using a standardised scenario planning method. Each of the scenarios are discussed, before being comparatively evaluated to identify the best- and worst-case scenarios. Such scenarios have not been developed before. This dissertation finds that professionals and companies in the construction industry are not slow to adopt new technologies. In addition, the diffusion of innovations theory and the developed Simple adopter categories are found to be appropriate for achieving the aim and objectives of this study. Additional research is recommended to validate the effectiveness of the Simple adopter categories for conducting diffusion research in other industries. Lastly, the need to accelerate the technology adoption propensity of companies in the construction industry is identified. This dissertation then develops actionable guidance to address some of the industry’s many concerns. Separate guidelines are developed for companies, technology developers, opinion leaders, and technology champions. These guidelines are not tested, and validation of their effectiveness is recommended for further research.
- ItemOn Reverse Representation(Stellenbosch University, 2024-12) Joubert, Gideo; Faul, P. F.; Janelide, Z.; Stellenbosch University. Faculty of Science. Dept. of Mathematical Sciences.Arthur Cayley’s famous representation theorem demonstrates to us that every group G can be realized as a subgroup of the group of automorphisms over some set X. Building on this foundational theorem, one can easily prove similar results for monoids and most generally faithful semigroups. The class of all semigroups with the property that ∀x,y∈X∀z∈X [xz = yz ⇒ x = y]. In this thesis, I establish the concept of reverse Cayley representation; a method of associating with any faithful semigroup S of transformations of a set X a (possibly empty) set of semigroups called unrepresentations. The set of unrepresentations of S is the set of exactly those faithful semigroups X on X with the property that X is represented as S. The goal of this thesis is to delve into reverse representation by defining and characterizing the unrepresentations of transformation structures at various levels of generality. We will look at a number of structures from the previously mentioned faithful semigroups of transformations to transformation groups. At each level I explore the fashion in which these unrepresentations arise and connect them to previously existing, or new, concepts. As I explore these unrepresentations, I will demonstrate that the set of unrepresentations of S is not merely a collection of structures, but has an algebraic structure itself. It is a heap, and this heap of unrepresentations is closely related to the group of ‘internal symmetries’ of any unrepresentation of S. This insight enables us to extend the concept of an invertible element into the realm of semigroups. In addition to this foundational work, I also investigate two special cases of unrepresentation: In the context of Clifford semigroups, Is how h ow t he unrepresentation of a structure can be broken up into various ‘smaller’ unrepresentations of component structures (along with an condition which specifies how these smaller unrepresentations should interact). Furthermore, in the context of category theory, I illustrate how the concept of representation (and thus unrepresentation) can be generalized- not from a group to a semigroup, but from a set to a graph.