Thesis (MBA) --University of Limpopo, 2008 / Despite crucial strategic value of fleets, most organizations have relegated the management of their vehicles as being very low on their list of priorities. Consequently, they are entrusting unsuitable people with management of their fleet. Without proper management, huge amounts of money are wasted through fuel fraud and with repairs being done too late or not at all, leaving expensive vehicles idle for months (Barrow 1999).It has been observed that managing fleets with the emphasis on bookkeeping and finance, rather than operational realities, leads to huge and unnecessary costs and massive fraud (Barrow 1998). Efficiency in fleet management is about having a fleet that works directly to support the organizational goals. It is imperative that a study was conducted to analyze the situation of pool cars in the Department of Water Affairs and Forestry (DWAF) in the Limpopo Province to ensure the efficiency in its fleet management

>Magister Scientiae - MSc / The lack of monitoring of non-perennial rivers is a major problem for water resources management, despite their significance in satisfying agricultural, economic and recreational needs. Pools in non-perennial rivers are not monitored, due to their remoteness. Remote sensing offers a promising alternative for the monitoring of changes in water storage in these pools. This study aims to assess the extent to which remotely-sensed datasets can be used to monitor the spatio-temporal changes of water storage of pools along non-perennial rivers in the Western Cape. The objectives of this study are: (1) to determine a suitable image preprocessing and classification technique for detecting and monitoring surface water along nonperennial rivers, and (2) to describe the spatial and temporal changes of water availability of pools along non-perennial rivers, using remotely sensed datasets. The Normalised Difference Water Index (NDWI), Modified NDWI (MNDWI), Normalised Difference Vegetation Index (NDVI), Automated Water Extraction Index for shadowed (AWEIsh) and non-shadowed regions (AWEInsh) and the Multi-Band Water Index (MBWI) classification techniques were investigated in this study, using the Sentinel-2 and Landsat 8 datasets. In-situ measurements were used to validate the satellite-derived datasets, while the use of high resolution aerial photography and Digital-Globe WorldView imagery were further compared to the results. The results suggested that the NDWI is the most suitable classification technique for identifying water in pools along non-perennial rivers throughout the Western Cape. The NDWI applied to the Sentinel-2 Top-of-Atmosphere (TOA) reflectance dataset had the highest overall accuracy of 85%, when compared to the Sentinel-2 Dark Object Subtraction 1 (DOS1) atmospheric correction, Sentinel-2 Sen2Cor atmospheric correction, Landsat 8 TOA reflectance and Landsat 8 DOS1 atmospheric correction datasets. The incorporation of atmospheric correction was shown to eliminate surface water pixels in many of the smaller pools.

Buffer pools are blocks of memory used in database systems to retain frequently referenced pages. Configuring the buffer pools is a difficult and manual task that involves determining the amount of memory to devote to the buffer pools, the number of buffer pools to use, their sizes, and the database objects assigned to each buffer pool. A good buffer configuration improves query response times and system throughput by reducing the number of disk accesses. Determining a good buffer configuration requires knowledge of the database workload. Empirical studies have shown that optimizing the initial buffer configuration (determined at database design time) can improve system throughput. A good initial configuration can also provide a faster convergence towards a favorable dynamic buffer allocation. Previous studies have not considered automating the buffer pool configuration process. This thesis presents two techniques that facilitate the initial buffer configuration task. First, we develop an analytic model of the GCLOCK buffer replacement policy that can be used to evaluate the effectiveness of a particular buffer configuration for a given workload. Second, to obtain the necessary model parameters, we propose a workload characterization scheme that extracts workload parameters, describing the query reference patterns, from the query access plans. In addition, we extend an existing multifractal model and present a multifractal skew model to represent query access skew. Our buffer model has been validated against measurements of the buffer manager of a commercial database system. The model has also been compared to an alternative GCLOCK buffer model. Our results show that our proposed model closely predicts the actual physical read rates and recognizes favourable buffer configurations. This work provides a foundation for the development of an automated buffer configuration tool.

From microscopic bacteria to the giant whale, every single living organism on Earth uses the same language of life: DNA. Deoxyribonucleoside triphosphates––dNTPs (dATP, dTTP, dGTP, and dCTP)––are the building blocks of DNA and are therefore the “alphabet of life”. A balanced supply of dNTPs is essential for integral DNA transactions such as faithful genome duplication and repair. The enzyme ribonucleotide reductase (RNR) not only synthesizes all four dNTPs but also primarily maintains the crucial individual concentration of each dNTP in a cell. In this thesis we investigated what happens if the crucial balanced supply of dNTPs is disrupted, addressing whether a cell has a mechanism to detect imbalanced dNTP pools and whether all pool imbalances are equally mutagenic. To address these questions, we introduced single amino acid substitutions into loop 2 of the allosteric specificity site of Saccharomyces cerevisiae RNR and obtained a collection of yeast strains with different but defined dNTP pool imbalances. These results directly confirmed that the loop 2 is the structural link between the substrate specificity and effector binding sites of RNR. We were surprised to observe that mutagenesis was enhanced even in a strain with mildly imbalanced dNTP pools, despite the availability of the two major replication error correction mechanisms: proofreading and mismatch repair. However, the mutagenic potential of different dNTP pool imbalances did not directly correlate with their severity, and the locations of the mutations in a strain with elevated dTTP and dCTP were completely different from those in a strain with elevated dATP and dGTP. We then investigated, whether dNTP pool imbalances interfere with cell cycle progression and if they are detected by the S-phase checkpoint, a genome surveillance mechanism activated in response to DNA damage or replication blocks. The S-phase checkpoint was activated by the depletion of one or more dNTPs. In contrast, when none of the dNTP pools was limiting for DNA replication, even extreme and mutagenic dNTP pool imbalances did not activate the S-phase checkpoint and did not interfere with the cell cycle progression. We also observed an interesting mutational strand bias in one of the mutant rnr1 strains suggesting that the S-phase checkpoint may selectively prevent formation of replication errors during leading strand replication. We further used these strains to study the mechanisms by which dNTP pool imbalances induce genome instability. In addition, we discovered that a high dNTP concentration allows replicative DNA polymerases to bypass certain DNA lesions, which are difficult to bypass at normal dNTP concentrations. Our results broaden the role of dNTPs beyond ‘dNTPs as the building blocks’ and suggest that dNTPs are not only the building blocks of DNA but also that their concentrations in a cell have regulatory implications for maintaining genomic integrity. This is important as all cancers arise as a result of some kind of genomic abnormality.

Globalization and demographic changes are posing new challenges for firms that compete for superior human capital resources, and this ‘war for talent’ is especially fierce among MNCs whose main asset is knowledge, like the consultancy industry. As the demand for future leaders increases, it is essential for such firms to ensure an efficient flow of diverse talent through the whole organization. Previous research has mainly treated diversity management and talent management separately, despite the fact that the two concepts are interrelated. This thesis aims to close this gap by exploring how global consultancies incorporate diversity into their talent management practices. By combining in-depth interviews and secondary data from three case companies, conclusions were drawn regarding the views and outcomes of diversity and through which practices the concept was integrated with the management of talents. Some interesting findings were that the main diversity focus was concentrated on gender issues and that global talent management was not highly prioritized in the participating case firms. With regards to talent management, the most highlighted strategy for achieving diversity was by focusing on attracting employees from different diverse groups.

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Globally, there is growing concern about energy consumption and its diverse effects on the environment. In South Africa, the current status quo is unfavourable in the domain of energy, hence the Department of Energy, Eskom and NERSA have embarked on supporting energy efficiency technologies nationwide as a strategic goal in reducing demand on the national grid. Due to the non conservative consumption of electricity from the grid and the insufficient supply to meet its demand, the importation of crude oil is very certain. In addition, the current and most popular technology for pool water heating in the said country is the resistive element which is inefficient and non-cost-effective. The energy consumption of residential swimming pool water heating is very massive, and tariff structure shows a constant rise. Furthermore, there's a current electricity crisis during the Eskom evening peak. Hence, a reliable, efficient, cost-effective and renewable energy technology such as an air source heat pump is required as a retrofit to the existing resistive element. Furthermore, mathematical modelling is a tool that can be used to mimic the dynamic behaviour of a physical or process system. It is a computational language or mathematical equation used to predict the dynamic behaviour of physical systems [Tangwe et al., 2015]. Various methods such as numerical methods have been considered as the particular types of mathematical modelling which have been employed to predict the performance of swimming pool ASHP water heater. However, they were unreliable and expensive. Consequently, this research focused on the experimental determination of the viability and development of a mathematical model to predict the performance of swimming pool ASHP water heater. The benefit of the development and building of this model was attributed to its low cost and credibility to forecast the performance of swimming pool ASHP water heater. Also, this robust mathematical model can be used by an energy service company and system manufacturer to compute the dynamic coefficient of performance of the swimming pool ASHP water heater. Following the above-mentioned information, the research sought to provide a permanent solution to the Eskom evening peak constraint. This is because energy-efficiency, serves as the bridging block between conventional and renewable energy sources needed by Eskom in a bid to provide a balance energy mix and sustainable energy. The implementation of a swimming pool ASHP water heater guaranteed a conducive environment for the population due to the reduction in environmental pollution.

Dry weather dominates several U.S. states, and some of them experience even long-term droughts. Yet, more than 10.6 million swimming pools exist in the U.S., and over 43,000 of them are in greater Los Angeles. Since roughly 100% of their water evaporates on a yearly basis, pool water evaporation accounts for a significant amount of water being wasted every day. Several studies have been conducted to create a proper equation for the evaporation rate on a pool surface, based on the wind speed, water temperature, and relative humidity. This thesis will address a research gap that was found in exploring the way the surroundings of the pool can affect its evaporation rate. In particular, this study examines the relation of the urban design to the evaporation rate of outdoor swimming pools by studying the way the housing type of a neighborhood affects the wind speed over the neighborhood’s pool surfaces.

A argamassa armada passou a ser utilizada na construção de reservatórios de água e piscinas no início da década de 60. Apesar do sucesso de várias aplicações, até hoje a tecnologia tem se fundamentado em bases empíricas, sem o estabelecimento de metodologias que permitam a elaboração de projetos, melhorias no método de construção e uma melhor avaliação dos riscos e da confiabilidade do sistema construtivo. O presente trabalho pretende contribuir para aumentar o conhecimento acerca do comportamento estrutural da membrana de argamassa armada em piscinas e reservatórios. Foram realizadas simulações numéricas por computador com o intuito de se investigar o comportamento da membrana quando submetidas à ação da água, de recalques e de variações de temperatura. A influência das dimensões da estrutura e da resistência da argamassa também foram analisadas. São discutidos estes e outros aspectos relacionados à fase de projeto. O trabalho apresenta ainda comentários sobre cada etapa de construção, bem como alguns cuidados necessários para a garantia de um material de boa qualidade. Tendo em vista a obtenção de uma estrutura durável e com bom desempenho, é preciso que cada equipe de trabalho tenha um palavra de ordem: aos projetistas, detalhamento; aos construtores, controle; à mão-de-obra, conscientização. / Ferrocement application in water tanks and swimming pools have started at the early 60\'s. Even though various applications had been succeed, until nowadays the techonology is essentially based on practical experience. There are no established methodologies which permit rational design, construction method improvement and a better assessment of the risks and reliability of the construction system. This work intend to contribute to the knowledge about the structural behavior of the ferrocement folded plate swimming pools and water tanks. Computer numerical simulations were made to investigate the membrane behavior under water loading, settlement and temperature variations. The influence of structure dimensions and mortar strength were also studied. These and others aspects related with the design method are discussed. The thesis also presents some comments about each construction stage as well as some cares needed to guarantee a good quality material. Looking for a durable and good performance structure, the order word to the designer is detailing, to the constructor is control and to the staff is awareness.

Transparens på den finansiella marknaden finns för att marknadsaktörer ska ha möjlighet att se vilka finansiella instrument det handlas med, i vilken volym och till vilket pris. Transparensen bidrar till mer tillgänglig information och en effektivare marknad, där priset på instrumentet speglar dess faktiska värde. I den här uppsatsen behandlas EU-direktivet MiFID II och förordningen MiFIR. Syftet med MiFID II och MiFIR är att komplettera den tidigare transparensregleringen och dessutom verka för en enhetlig reglering på den europeiska finansiella marknaden. De flesta artiklarna angående transparens finns i MiFIR, vilka reglerar krav på transparens, men också undantag från transparens. Ett stort problem som finns på dagens finansiella marknad är att många transaktioner inte är föremål för transparens, utan görs i så kallade Dark Pools eller utanför handelsplatser. När handel sker i Dark Pools eller utanför en handelsplats är det svårt för marknadsaktörer att få tillgång till information om vilka och i vilken omfattning det handlas med instrumenten. Fördelen för de aktörer som handlar i Dark Pools och utanför en handelsplats är att de inte behöver exponera sina transaktioner och därmed inte heller dela med sig av eventuellt informationsövertag. Handel i Dark Pools och utanför handelsplatser är dessutom oftast billigare än handel på exempelvis börsen. Huvudsyftet med MiFID II och MiFIR är att, genom att begränsa handeln som sker i Dark Pools och utanför handelsplatser, öka transparensen på den finansiella marknaden. Trots detta visar lagstiftaren vikten av att väga andra intressen, som kan missgynnas av transparens, genom att införa flera olika undantag från transparenskraven. MiFID II och MiFIR träder i kraft först den 3 januari 2018, vilket gör det svårt att förutse regelverkets framtida följder. Det är först efter införandet av regelverket som vi kommer att se hur marknadsaktörerna reagerar på kraven och möjligheterna till undantagen. För att i uppsatsen kunna analysera en potentiell reaktion på den svenska finansiella marknaden, beaktas den svenska inställningen till tidigare transparensreglering. Vidare vägs fördelar med transparenskraven mot nackdelar och undantagens omfattning och utformning analyseras. Slutsatsen är att transparensreglerna kommer att öka transparensen på marknaden, i den mån att transparensen inte äventyrar den effektiva prisbildningen.