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Browsing by Author "Durbach, Ian"

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Adapting Large-Scale Speaker-Independent Automatic Speech Recognition to Dysarthric Speech

Author: Houston, Charles Date: 2022 Despite recent improvements in speaker-independent automatic speech recognition (ASR), the performance of large-scale speech recognition systems is still significantly worse on dysarthric speech than on standard speech. Both the inherent noise ... Read more
Agent-based model of the market penetration of a new product

Author: Magadla, Thandulwazi Date: 2014 This dissertation presents an agent-based model that is used to investigate the market penetration of a new product within a competitive market. The market consists of consumers that belong to social network that serves as a substrate over ... Read more
An exploration of media repertoires in South Africa: 2002-2014

Author: Bakker, Hans-Peter Date: 2019 This dissertation explores trends in media engagement in South Africa over a period from 2002 until 2014. It utilises data from the South African Audience Research Foundation’s All Media and Products Surveys. Using factor analysis, six media ... Read more
Blow me down: A new perspective on Aloe dichotoma mortality from windthrow

Author: Jack, Samuel L ; Hoffman, Michael T ; Rohde, Rick F ; Durbach, Ian ; Archibald, Margaret Date: 18 Mar 2014 Background: Windthrow, the uprooting of trees during storms associated with strong winds, is a well-established cause of mortality in temperate regions of the world, often with large ecological consequences. However, this phenomenon has ... Read more c b
Classification and visualisation of text documents using networks

Author: Phaweni, Thembani Date: 2018 In both the areas of text classification and text visualisation graph/network theoretic methods can be applied effectively. For text classification we assessed the effectiveness of graph/network summary statistics to develop weighting schemes ... Read more
Counting animals in ecological images

Author: Pillay, Nakkita Date: 2022 In the field of ecology, counting of animals to estimate population size and prey abundance is important for the conservation of wildlife. This involves analyzing large volumes of image, video or audio data and manual counting. Automating the ... Read more
Decision support for the production and distribution of electricity under load shedding

Author: Rakotonirainy, Rosephine Georgina Date: 2016 Every day national power system networks provide thousands of MW of electric power from generating units to consumers. This process requires different operations and planning to ensure the security of the entire system. Part of the daily or ... Read more
Deep neural networks for video classification in ecology

Author: Conway, Alexander Date: 2020 Analyzing large volumes of video data is a challenging and time-consuming task. Automating this process would very valuable, especially in ecological research where massive amounts of video can be used to unlock new avenues of ecological ... Read more
Detection and Isolation of Prey Capture Events in Animal-Borne Images

Author: Chirwa, Temweka S Date: 2021 Understanding the foraging habits and prey availability for a species is crucial. Prey availability is crucial to a species' survival and sustainability of the food pyramid. Identifying the type of prey consumed also allows ecologists to ... Read more
Machine learning methods for individual acoustic recognition in a species of field cricket

Author: Dlamini, Gciniwe Date: 2018 Crickets, like other insects, play a vital role in maintaining a balance in the ecosystem. Therefore, the ability to identify individual crickets is crucial as it enables ecologists to estimate important population metrics such as population ... Read more
Measuring the rebound effect of energy efficiency initiatives for the future: A South African case study

Author: Davis, Stephen ; Cohen, Brett ; Hughes, Alison ; Durbach, Ian ; Nyatsanza, Kudakwashe Date: 2011 The rebound effect is a phrase which was originally defined to refer to the extent to which energy efficiency improvements are lost due to subsequent behavioural changes. This report documents almost three years of research work that set out ... Read more
Mining a large shopping database to predict where, when, and what consumers will buy next

Author: Halam, Bantu Date: 2020 Retailers with electronic point-of-sale systems continuously amass detailed data about the items each consumer buys (i.e. what item, how often, its package size, how many were bought, whether the item was on special, etc.). Where the retailer ... Read more
Modelling household responses to energy efficiency interventions via system dynamics and survey data

Author: Davis, Stephen ; Durbach, Ian Date: 2010 An application of building a system dynamics model of the way households might respond to interventions aimed at reducing energy consumption (specifically the use of electricity) is described in this paper. A literature review of past research ... Read more c b
Modelling the range-wide density patterns of the Arthroleptella lightfooti using acoustic monitoring data

Author: Poongavanan, Jenicca Date: 2019 Species distributions are often limited by environmental factors and according to the abundant—centre hypothesis, abundance should be highest Where the environment is most favourable for the species. So, do the same environmental factors ... Read more
Natural Language Processing on Data Warehouses

Author: Maree, Stiaan Date: 2019 The main problem addressed in this research was to use natural language to query data in a data warehouse. To this effect, two natural language processing models were developed and compared on a classic star-schema sales data warehouse with ... Read more
Optimisation of complex simulation models

Author: Bezuidenhoudt,Cecile Margaret Date: 2013 Computer simulation models are widely and frequently used to model real systems to predict output responses under specified input conditions. Choosing optimal simulation parameters leads to improved operation of the model but it is still a ... Read more
Player performance evaluation in rugby using Stochastic Multi-Criteria Acceptability Analysis with simplified uncertainty formats

Author: Calder, Jon Matthew Date: 2013 This dissertation considers problem contexts in which decision makers are unable or unwilling to assess trade-off information precisely. The primary aim is to investigate the use of Stochastic Multi-criteria Acceptability Analysis (SMAA) with ... Read more
Resource constraints in an epidemic: a goal programming and mathematical modelling framework for optimal resource shifting in South Africa

Author: Mayet, Saadiyah Date: 2021 The COVID-19 pandemic has had devastating consequences across the globe, and has led many governments into completely new decision making territory. Developing models which are capable of producing realistic projections of disease spread under ... Read more
Simplified approaches for portfolio decision analysis

Author: Kantu, Dieudonne Kabongo Date: 2022 Traditional choice decisions involve selecting a single, best alternative from a larger set of potential options. In contrast, portfolio decisions involve selecting the best subset of alternatives — alternatives that together maximize some ... Read more
Species distribution modelling of Aloidendron dichotomum (quiver tree)

Author: Dube, Qobo Date: 2018 A variety of species distribution models (SDMs) were fit to data collected by a 15,000km road-side visual survey of Aloidendron dichotomum populations in the Northern Cape region of South Africa, and Namibia. We fit traditional presence/absence ... Read more