PREDICTIVE MODELLING OF VEHICLE SPEEDS WHILE TRAVERSING MODERN ROUNDABOUTS BASED ON GEOMETRIC DESIGN CHARACTERISTICS

Thesis (PhD)--Stellenbosch University, 2025.Arries, J. T. 2025. Predictive modelling of vehicle speeds while traversing modern roudabouts based on geometric design characteristics. Unpublished doctoral dissertation. Stellenbosch: Stellenbosch Univeristy [online]. Available: https://scholar.sun.ac.za/items/b566a71f-76a4-4a74-b740-d53a78ce0e30Roundabouts are increasingly preferred over traditional signalised and stop-controlled intersections due to their enhanced safety performance, primarily achieved by reducing conflict points and enforcing lower vehicle speeds through successive reverse curves. To ensure these benefits, accurate tools for assessing vehicle speed reduction are essential for roundabout design. Current international methodologies for speed estimation in roundabouts rely on iterative approaches involving sketches of potential fastest and entry paths, which introduce subjective variability and often yield inconsistent estimates for maximum attainable vehicle speeds through roundabouts. These limitations highlight the need for alternative, empirical methods that offer precision and consistency. This dissertation addresses this gap by proposing alternative, empirical methodologies grounded in realworld data to improve the precision of speed estimates at roundabouts. The study examines geometric features and upstream speeds that statistically impact maximum attainable vehicle speeds at entry, circulating, and exit points for left-turn and straight movements through roundabouts. Empirical multivariate regression models are developed to replace subjective judgment with objective criteria, yielding more reliable speed estimates. Findings reveal complex interdependencies between geometric features and vehicle speeds, particularly at entry points, where traditional models face notable limitations. To overcome these challenges, the research proposes and evaluates neural network models, capitalising on their capacity to capture intricate, non-linear relationships between predictors and thereby enhancing speed estimation accuracy, especially at roundabout entry points. The findings reveal that empirical models, both regression and neural network-based, are able to produce enhanced speed estimation models at roundabouts. This research proposes novel methodologies for speed estimation, marking an advancement in the application of empirical regression and neural networks to capture intricate relationships within traffic engineering and transportation planning. Although focused on roundabout speeds, these methodologies demonstrate the broader potential of data-driven models for quantifying complex relationships in traffic engineering between road geometry and operational speeds. This work also contributes a guideline for evaluating speeds and performance metrics at roundabouts, advocating for empirical data-based models to deepen understanding of complex dynamics in traffic and transportation systems. These methodologies demonstrate how empirical, data-driven approaches can significantly advance intersection design and safety.Doctora

Conceptualising a system for quality clinical decision-making in nursing: review

Quality clinical decision-making in nursing is the essence of quality nursing care delivery. The purpose of this article is to conceptualise a system for quality clinical decision-making in nursing. A system for quality clinical decisionmaking in nursing was conceptualised based on a review of the literature pertaining to clinical decision-making. To that effect, both published and unpublished references were reviewed. The review revealed two predominant theoretical perspectives of the process of clinical decision-making: a positivistic perspective and a postmodernistic perspective. These perspectives are respectively exemplified by an information-processing approach and the intuitive approach to clinical decision-making in nursing. The strengths and weaknesses of both approaches were explored and, as a result, a third theoretical approach emerges: the idea of a dialectic, integrative, interactive approach that culminates in the conceptualisation of a system for quality clinical decision-making in nursing. According to a system for quality clinical decision-making, clinical decision-making is viewed as an open system in which both approaches, described as a "piece-meal" approach (Tabak & Bar-Tal, 1996:1-2) and an intuitive approach (Benner, 1984) can be used in a complementary manner to achieve quality clinical decisions in nursing. As a feedback mechanism to promote or improve the quality of clinical decisions in nursing, standards for quality clinical decision-making are proposed in an exemplary manner. In addition, a system for quality clinical decisionmaking in nursing capitalises on the heritage of the nursing process. Considering the changes and the complexities associated with clinical decision-making in nursing, the system accommodates recent knowledge development activities in nursing, such as developments in nursing classification systems and the classification of nursingsensitive patient outcomes. Key Words: Clinical decision-making; Quality; Rational interaction; Standard and system OPSOMMING Gehalte kliniese besluitneming in verpleging word beskou as die essensie van gehalte verpleegsorg. Die doel van hierdie artikel is om ‘n sisteem vir gehalte besluitneming in verpleging te konseptualiseer. Die konseptualisering van ‘n sisteem vir gehalte kliniese besluitneming in verpleging is op die bestudering van die literatuur oor kliniese besluitneming gegrond. Beide gepubliseerde en ongepubliseerde verwysingsbronne is bestudeer. Twee dominante perspektiewe, ‘n positivistiese perspektief en ‘n postmodernistiese perspektief, met betrekking tot die proses van kliniese besluitneming is na aanleiding van die bestudering van die literatuur geïdentifiseer. Hierdie perspektiewe word onderskeidelik deur ‘n inligtingsverwerkingsbenadering en ‘n intuïtiewe benadering tot kliniese besluitneming in verpleging beliggaam. Die goeie hoedanighede en tekortkominge van beide benaderings is verken en ‘n derde teoretiese benadering het gevolglik tot stand gekom: die idee van ‘n dialektiese, geïntegreerde, interaktiewe benadering wat in die konseptualisering van ‘n sisteem vir gehalte besluitneming in verpleging kulmineer. Volgens ‘n sisteem vir gehalte besluitneming in verpleging, word kliniese besluitneming beskryf as ‘n stuksgewyse benadering (Tabak & Bar-Tal, 1996:1-2) en/of ‘n intuïtiewe benadering (Benner, 1984), wat op ‘n aanvullende wyse aangewend kan word, om gehalte besluitneming in verpleging te kan laat plaasvind. Standaarde vir gehalte besluitneming, in die vorm van ‘n voorbeeld, word as terugvoermeganisme voorgestel, ten einde die gehalte van kliniese besluitneming in verpleging te bevorder en te verbeter. Voorts, kapitaliseer ‘n sisteem vir gehalte besluitneming in verpleging op die herkoms van die verpleegproses. Deur die veranderinge en kompleksiteit wat met kliniese besluitneming gepaard gaan, akkommodeer dit resente kennis in verband met ontwikkelingsaktiwiteite in verpleging, soos die ontwikkeling van ‘n verpleegklassifikasiesisteem en die klassifikasie van uitkomste ten opsigte van die verpleegsensitiewe-pasiënt. Health SA Gesondheid Vol.9(3) 2004: 66-8

Local development needs and aspirations and the international Square Kilometre Array radio telescope: views from Amandelboom, Williston in South Africa.

Thesis (MA)--Stellenbosch University, 2023.ENGLISH ABSTRACT: This thesis looks at the 'community development' component of the Human Capital Development Programme (HCDP) that the South African Radio Astronomy Observatory (SARAO) is managing in the four small Karoo towns that are closest to the Square Kilometre Array (SKA) radio astronomy project in the Northern Cape and how well matched this programme is to local development needs and aspirations. It does so from the perspective of people living in Amandelboom, a poor neighbourhood in Williston, which is one of the towns targeted to benefit from the local development commitments of the HCDP. Amandelboom is one of the two residential areas into which Williston is divided, the other one being the Dorp (die Dorp, as local people call it in Afrikaans). The other three towns are Brandvlei, Carnarvon and Vanwyksvlei. All four towns experience an array of social and economic challenges similar to those found in other small towns in the Karoo. The thesis employs a qualitative research design involving semi-structured interviews, observation and a photovoice exercise inspired by participatory action research (PAR) methods to explore the views of people living in Amandelboom on their needs and aspirations and their views on the SKA. In unpacking socio-economic conditions in Amandelboom I have also been able to draw on a representative household survey conducted in Williston in 2021. The conceptual framework draws primarily on understandings of development advanced by Amartya Sen (Development as Freedom, 1999) and Holden et al. (2017) as well as the work of Hart (2016) and Appadurai (2004) on aspirations. This framework also draws on Maslow’s hierarchy of human needs while engaging critically with human capital theory. The main findings of this research are that the residents of Amandelboom do not regard SARAO’s local development projects as fitting satisfactorily with their specific development needs and aspirations, in part because of its emphasis on developing human capital through investment in science and maths education which very few regard as a priority for themselves. People in Williston also complain that most of the focus of local development projects is on Carnarvon. In conclusion this thesis addresses ideas around responsibility versus the response-ability of different stakeholders when it comes to community development initiatives. Central to this distinction is the argument that there should be a greater focus on local needs and aspirations and more inclusive decision-making processes that include local people when development initiatives aimed at them are designed.AFRIKAANSE OPSOMMING: Hierdie tesis kyk na die gemeenskapsontwikkeling komponent van die Human Capital Development program (HCDP) wat deur die South African Radio Astronomy Observatory’(SARAO) bestuur word in die vier klein Karoo dorpe wat die naaste aan die Square Kilometre Array (SKA) radio astronomie projek in die Noord-Kaap provinsie is. Die fokus van hierdie navorsingstuk is op hoe goed gepas die plaaslike ontwikkelings prioriteite van die SKA is teenoor plaaslike behoeftes en begeertes. Dit kyk na hierdie aspekte vanaf die perspektief van diegene wie woon in Amandelboom, 'n arme buurt in Williston, een van vier dorpe wat geidentifiseer is as begunstigde vir die SKA se HCD. Amandelboom is een van twee woongebiede waarin Williston verdeel is; die ander is die Dorp, soos plaaslike mense dit in Afrikaans noem. Die ander drie dorpe wat begunstigdes is, is Brandvlei, Carnarvon en Vanwyksvlei. Al vier dorpe ervaar uiterse uitdagende omstandighede in terme van hul sosiale en ekonomiese-landskappe soortgelyk aan dié wat in ander klein dorpies in die Karoo voorkom. Die tesis maak gebruik van n kwalitatiewe navorsingsontwerp wat semi-gestruktureerde onderhoude, waarnemings en 'n photovoice oefening insluit, geïnspireer deur deelnemende aksienavorsingsmetodes (PAR) om die sienings van mense wie in Amandelboom woon oor hul behoeftes en aspirasies en hul sienings oor die SKA te ondersoek. Met die ontleding van die sosio-ekonomiese toestande in Amandelboom kon ek ook gebruik maak van 'n verteenwoordigende huishoudelike opname wat in 2021 in Williston gedoen is. Die konsepsuele raamwerk maak hoofsaaklik gebruik van begrip van ontwikkeling wat deur Amartya Sen (Development as Freedom, 1999) en Holden et al. (2017) sowel as die werk van Hart (2016) en Appadurai (2004) rondom aspirasies. Hierdie raamwerk maak ook gebruik van Maslow se hiërargie van menslike behoeftes terwyl hy krities met die menslikekapitaalteorie omgaan. Die hoofbevindings van hierdie navorsing is dat die inwoners van Amandelboom nie SARAO se plaaslike ontwikkelingsprojekte as bevredigend by hul spesifieke ontwikkelingsbehoeftes en aspirasies beskou nie, deels vanweë die klem op die ontwikkeling van menslike kapitaal deur belegging in wetenskap- en wiskunde-onderwys wat baie min as 'n prioriteit vir hulself beskou. Mense in Williston kla ook dat die meeste van die fokus van plaaslike ontwikkelingsprojekte op Carnarvon gefokus is.Master

Practice standards for quality clinical decision-making in nursing

The purpose of this study is to formulate practice standards for quality clinical decision making in nursing. Clinical decision-making is a critical component of nursing practice, as the life of the patient is at stake. The quality of clinical decision-making is, therefore, essential in delivering quality nursing care. The facilitation of quality clinical decision-making in nursing requires the development of standards to monitor, evaluate and implement remedial actions that improve on the quality of clinical decision-making (Muller, 2002:203; Beyea &amp; Nicoll, 1999:495). However, there are no such practice standards against which the quality of clinical decision-making by nurses can be evaluated and assessed. A qualitative, explorative, descriptive and standard formulation research design (Mouton &amp; Marais, 1990:45-46; Muller, 1990:49-55) has been followed to develop standards for quality clinical decision-making in nursing. Standard development was based on the principles described by Muller (in Booyens, 1998:607-608; 636-637), and consists of development and quantification phases that are modified to meet the requirements for instrument development, as described by Lynn (1986:382-385). The formulation of these practice-standards was derived deductively from a conceptual framework. The conceptual framework was constructed based on an exploration and description of the expectations of the stakeholders about quality clinical decisionmaking in nursing and a literature study on clinical decision-making. To ensure the credibility of the standards for clinical decision-making in nursing, principles of logic, prolonged engagement, triangulation, peer-group discussion, dense description, stepwise repetition and an investigative audit (Lincoln &amp; Guba, 1985:289-331) were adhered to. Two experts were consulted to validate the standards for quality clinical decisionmaking in nursing.</jats:p

Knowledge, perceptions, and practices of the healthcare team involved in stem cell transplantation

A study was done to see if nurses who are practicing in stem cell transplantation units, have knowledge and what their perceptions are about the treatment options available

Knowledge, perceptions and practices of members of the health care team involved in stem cell transplantations in the Western Cape

Thesis (MTech (Nursing))--Cape Peninsula University of Technology, 2017.Stem cell transplantation has become one of the standard methods of treatment for patients with malignant and benign blood disorders. The multidisciplinary team interacting with these patients and their families, must be knowledgeable concerning the appropriate quality health care. The objectives of the study were to explore the knowledge of the members of the health care team in terms of the processes that need to be adhered to with stem cells transplantation, as well as exploring the perceptions amongst the health care team members and their reactions towards patients undergoing stem cell transplantation. An exploratory research design with a qualitative approach was employed. Data collection took place at two stem cell transplant units in the Western Cape, using non-probability purposive sampling technique. The health care team members included a medical doctor, dietician, physiotherapist, social worker, radiographer and nursing staff. Data was collected by face-to-face personal interviews which were transcribed and analysed by using coding and thematic analysis. The majority of the professional participants could identify the processes for stem cell transplantation, which affirmed their knowledge. The non-professional health care team member, could also identify the types of methods and processes of stem cell transplantation. Participants stated that the health care team members had passion for this treatment option. Some participants felt it to be emotionally challenging to work in the environment, especially with paediatric patients and the dying. However, some health care team members could detach themselves emotionally from the patients. The team stated that the stem cell transplanted patients need special care to overcome all challenges experienced, but were positive about treatment. It is evident that management of stem cell transplanted patients is complicated and the health care team members must have knowledge, skills and the appropriate attitude to practice in these units. This study emphasised how vital it is that stem cell transplantation be included in the training programs of the multidisciplinary team. Health care practitioners in the field must stay abreast with stem cell research in order to effectively conduct health promotions for patients and staff. In addition, hematology and transplant awareness campaigns should also be conducted in order to educate society and suggest referrals if necessary

A case study of the use of code-blending by a bimodal bi-/multilingual deaf family

Thesis (MA)--Stellenbosch University, 2024.ENGLISH ABSTRACT: When children, either deaf or hearing, are exposed to a spoken language and a signed language, they often become bimodal bilinguals. Bimodal bilinguals are able to produce both speech and sign at the same time, as the two modalities allow for the simultaneous production of two languages. This is known as code-blending. This study examines the language practices of a bimodal bi-/multilingual family, focusing on the phenomena of code-blending and code-switching. The current thesis examines the dinnertime conversations of a deaf family from Worcester, which includes deaf parents and two hearing twin girls (aged 9). All participants are bimodal multilinguals. The study involves the analysis of the family’s code choices (code-blending and code-switching patterns) during approximately one hour of recorded dinnertime interaction. Utterances which showed evidence of code-blending and code-switching were analysed. Coding was done according the turns each participant produced. There has been very limited studies on either bimodal bi-/multilingualism, or code-blending in bimodal bi-/multilingual families, especially in the South African context. The present study aims to provide a description on the linguistic choices of the hearing children of deaf adults (CODAs). Examining the bimodal bi-/multilingual family interactions during dinnertime has shown that the children and parents prefer to communicate in their dominant mode, Afrikaans and SASL respectively. When communicating with their parents, the children rather code-blend than code-switch fully into SASL This result is similar to previous research, as it shows the same preference, in which the children code-blend more than code-switch. Albeit with a small number of participants, the results have given some insight into the patterns of code-blending and code-switching in bimodal bi-/multilingual families.AFRIKAANSE OPSOMMING: Wanneer kinders, hetsy doof of horend, aan 'n gesproke taal en 'n gebaretaal blootgestel word, word hulle dikwels bimodale tweetaliges. Bimodale tweetaliges is in staat om beide spraak en gebare op dieselfde tyd te produseer, aangesien die twee modaliteite die gelyktydige produksie van twee tale moontlik maak. Dit staan bekend as kodevermenging. Hierdie studie ondersoek die taalpraktyke van 'n bimodale twee-/meertalige gesin, met die fokus op die verskynsels van kodevermenging en kodewisseling. Die huidige tesis ondersoek die aandetegesprekke van 'n dowe gesin van Worcester, wat dowe ouers en twee horende tweelingmeisies (9 jaar oud) insluit. Alle deelnemers is bimodale veeltaliges. Die studie behels die ontleding van die gesin se kodekeuses (kodevermenging en kodewisselingspatrone) gedurende ongeveer een uur van opgeneemde aandetetydinteraksie. Uiting wat bewyse van kodevermenging en kodewisseling getoon het, is ontleed. Kodering is gedoen volgens die beurte wat elke deelnemer geneem het. Daar is baie beperkte studies oor óf bimodale twee-/veeltaligheid, óf kodevermenging in bimodale twee-/meertalige gesinne, veral in die Suid-Afrikaanse konteks. Die huidige studie het ten doel om 'n beskrywing te verskaf oor die linguistiese keuses van die horende kinders van dowe volwassenes (sogenaamde CODA's). Die ondersoek van die bimodale twee-/meertalige gesinsinteraksies tydens etenstyd het getoon dat die kinders en ouers verkies om in hul dominante modus, onderskeidelik Afrikaans en SASL, te kommunikeer. Wanneer daar met hul ouers gekommunikeer word, gebruik die kinders eerder kodevermenging as om volledig na SASL oor te skakel. Hierdie resultaat is soortgelyk aan vorige navorsing, aangesien dit dieselfde voorkeur toon, waarin die kinders meer kodevermeng as kodewissel. Alhoewel dit 'n klein aantal deelnemers insluit, het die resultate 'n mate van insig gegee in die patrone van kodevermenging en kodewisseling in bimodale twee-/veeltalige gesinne.Master

What Sentiment and Fun Facts We Learnt Before FIFA World Cup Qatar 2022 Using Twitter and AI

Twitter is a social media platform bridging most countries and allows real-time news discovery. Since the tweets on Twitter are usually short and express public feelings, thus provide a source for opinion mining and sentiment analysis for global events. This paper proposed an effective solution, in providing a sentiment on tweets related to the FIFA World Cup. At least 130k tweets, as the first in the community, are collected and implemented as a dataset to evaluate the performance of the proposed machine learning solution. These tweets are collected with the related hashtags and keywords of the Qatar World Cup 2022. The Vader algorithm is used in this paper for sentiment analysis. Through the machine learning method and collected Twitter tweets, we discovered the sentiments and fun facts of several aspects important to the period before the World Cup. The result shows people are positive to the opening of the World Cup

Operational conditions of continuous wave doppler radar devices for accurate vehicle speed measurement in trafic management

Papers presented virtually at the 42nd International Southern African Transport Conference on 08 - 11 July 2024Doppler radar technology plays a crucial role in vehicle speed measurement and enforcement, making it an integral part of transportation and traffic management systems. This study investigates the limitations of continuous wave (CW) Doppler radar technology, with a specific focus on practical implications within the transport industry. While CW Doppler radar is a valuable tool, its optimal performance is contingent on specific conditions. This research demonstrates real-world limitations which can influence the accuracy of speed measurements. The findings underscore the necessity for stricter operational guidelines to address these limitations in less-than-ideal conditions. A comprehensive understanding of Doppler radar behaviour, coupled with improved operating protocols, can enhance its effectiveness in real-world traffic scenarios. The findings aid in advocating for the establishment of enhanced operational standards for Doppler radars in vehicle speed measurement and enforcement. By addressing the limitations and proposing practical solutions, the transport industry can optimise the use of Doppler radar technology for more accurate and reliable traffic management. This paper aims to provide a comprehensive perspective that benefits both industry professionals and government officials, bridging the gap between engineering aspects and practical implications in the transportation and traffic management sectors

Utilising uavs and AI software for data collection at roundabouts

Papers presented virtually at the 41st International Southern African Transport Conference on 10-13 July 2030The use of Unmanned Aerial Vehicles (UAVs) for traffic observation has increased with advances in both drone technologies and video analytics. Improvements in video analytics for identifying and tracking vehicles in two dimensions means that it is now possible to collect and analyse vehicle paths and traffic movement dynamics. This is useful for understanding vehicle movements through roundabouts. This paper will report on a large study using UAVs to collect data at over 100 roundabouts across four regions in South Africa, specifically considering the process of data collection using drones and the software requirements for data extraction. Vehicle operations at roundabouts were recorded by UAV-mounted cameras during peak traffic hours from optimal vantage points. The footage was then uploaded to a cloud-based video analytics platform for processing and scaled to the relevant coordinate system. The video analytics platform was found to provide accurate measurements and movement dynamics of vehicles as they travel through the camera view. Analytics that are directly available from the platform include point speeds at specific locations, acceleration, deceleration, and gap acceptance. Traffic counts and turning movements are also identified because every vehicle traversing the roundabout is tracked. This paper will further report on the post-analysis techniques that were followed to analyse the data and extract the relevant performance measures required for further research