Browsing by Subject "efficiency"

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    Efficiency, returns to scale, and technology gaps in the short-term insurance industry in sub-Saharan Africa
    (2026) Thato, Kontle; Alhassan, Abdul Latif
    As part of the insurance industry, the short-term insurance segment is an integral part of the financial services sector. Through this segment, individuals, businesses, and governments can hedge against various types of risks, including manmade and natural catastrophes. Hence, the productive performance of this industry is essential. This study examines the efficiency, returns to scale and technological gaps in the short-term insurance industry in six selected sub-Saharan African countries over the period 2011-2017. The study employs a bootstrapped metafrontier data envelopment analysis approach to measure efficiencies and the Wilcoxon-Mann-Whitney statistic to explore performance differences across countries. The results show lower levels of metafrontier technical and managerial efficiencies across all countries. A comparison of firms in different countries reveals that South African firms have higher technical efficiency scores and smaller technological gaps than firms from other countries. The low average metafrontier efficiencies across firms indicate the need to adopt state-of-the-art technology, especially outside South Africa. Besides, firms in most countries appear to operate with increasing returns to scale. The evidence also suggests that firm size, foreign ownership, group affiliation, and reinsurance are the drivers of efficiency and technology gaps in sample markets while firm size, leverage, domestic ownership, and reinsurance are the factors that influence insurers' probability of operating with constant returns to scale. group affiliation is an important determinant of short-term insurer performance. One of the implications of this thesis is that governments should promote technological adoption through incentives and support scaling operations via regulatory easing and financial incentives. Additionally, attracting foreign investment, reassessing reinsurance practices, and investing in capacity building and training are essential for improving efficiency and closing technology gaps.
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    Estimating aerodynamic roughness over complex surface terrain
    (2013) Nield, Joanna M; King, James; Wiggs, Giles F S; Leyland, Julian; Bryant, Robert G; Chiverrell, Richard C; Darby, Stephen E; Eckardt, Frank D; Thomas, David S G; Vircavs, Larisa H; Washington, Richard
    Surface roughness plays a key role in determining aerodynamic roughness length (zo) and shear velocity, both of which are fundamental for determining wind erosion threshold and potential. While Zocan be quantified from wind measurements, large proportions of wind erosion prone surfaces remain too remote for this to be a viable approach. Alternative approaches therefore seek to relate Zoto morphological roughness metrics. However, dust-emitting landscapes typically consist of complex small-scale surface roughness patterns and few metrics exist for these surfaces which can be used to predict Zofor modeling wind erosion potential. In this study terrestrial laser scanning was used to characterize the roughness of typical dust-emitting surfaces (playa and sandar) where element protrusion heights ranged from 1 to 199 mm, over which vertical wind velocity profiles were collected to enable estimation of zo. Our data suggest that, although a reasonable relationship (R2> 0.79) is apparent between 3-D roughness density and Zo, the spacing of morphological elements is far less powerful in explaining variations in Zothan metrics based on surface roughness height (R2 > 0.92). This finding is in juxtaposition to wind erosion models that assume the spacing of larger-scale isolated roughness elements is most important in determining Zo. Rather, our data show that any metric based on element protrusion height has a higher likelihood of successfully predicting Zo. This finding has important implications for the development of wind erosion and dust emission models that seek to predict the efficiency of aeolian processes in remote terrestrial and planetary environments.
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    Interannual memory effects for spring NDVI in semi-arid South Africa
    (2008) Richard, Yves; Martiny, Nadège; Fauchereau, Nicolas; Reason, Chris; Rouault, Mathieu; Vigaud, Nicolas; Tracol, Yann
    Almost 20 years of Normalized Difference Vegetative Index (NDVI) and precipitation (PPT) data are analysed to better understand the interannual memory effects on vegetation dynamics observed at regional scales in Southern Africa (SA). The study focuses on a semi-arid region (25°S–31°S; 21°E–26°E) during the austral early summer (September–December). The memory effects are examined using simple statistical approaches (linear correlations and regressions) which require the definition of an early summer vegetation predictand (December NDVI minus September NDVI) and a consistent set of potential predictors (rainfall amount, number of rainy days, rainfall intensity, NDVI and Rain-Use-Efficiency) considered with 4 to 15-month time-lag. An analysis over six SA sub-regions, corresponding to the six major land-cover types of the area reveals two distinct memory effects. A “negative” memory effect (with both rainfall and vegetation) is detected at 7 to 10-month time-lag while a “positive” memory effect (with vegetation only) is observed at 12 to 14-month time-lag. These results suggest that interannual memory effects in early summer vegetation dynamics of semi-arid South Africa may preferably be driven by biological rather than hydrological mechanisms.
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    PHOTOMETRIC TYPE Ia SUPERNOVA CANDIDATES FROM THE THREE-YEAR SDSS-II SN SURVEY DATA
    (2011) Sako, Masao; Bassett, Bruce; Connolly, Brian; Dilday, Benjamin; Cambell, Heather; Frieman, Joshua A; Gladney, Larry; Kessler, Richard; Lampeitl, Hubert; Marriner, John; Miquel, Ramon; Nichol, Robert C; Schneider, Donald P; Smith, Mathew; Sollerman, Jesper
    We analyze the three-year Sloan Digital Sky Survey II (SDSS-II) Supernova (SN) Survey data and identify a sample of 1070 photometric Type Ia supernova (SN Ia) candidates based on their multiband li ...
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    The efficiency and effectiveness of an academic library collection from the perspective of postgraduate students, academics and library professionals: collection evaluation at a University of Technology
    (University of Cape Town, 2026) Sandase, Thembisile; Kahn, Michelle
    Collection evaluation is one of the important aspects of the collection management process. Libraries evaluate their collections to ensure that they serve and satisfy users' needs. The purpose of this study was to evaluate the efficiency and effectiveness of a library collection. The pragmatic research paradigm was used where both qualitative and quantitative methods (convergent mixed methods approach) were used through a case study of a University of Technology. The study is framed by Evans and Saponaro's (2019) model of the collection management process. The population of the study was postgraduate students, academic staff and library professionals. Convenience sampling was used to select students while purposive sampling was used to select staff for interviews. Self-administered questionnaires were distributed to students, while semi-structured interviews were conducted with academics and library professionals. Quantitative and qualitative data were collected. The findings of the study revealed that all the participants were satisfied to some extent with the collection, although the audiovisual collection is outdated and obsolete and needs some improvement. Findings also depicted that reference and print journal collections should be updated to better support the users' needs and academic activities.