Improved Text Language Identification for the South African Languages

Virtual assistants and text chatbots have recently been gaining popularity. Given the short message nature of text-based chat interactions, the language identification systems of these bots might only have 15 or 20 characters to make a prediction. However, accurate text language identification is important, especially in the early stages of many multilingual natural language processing pipelines. This paper investigates the use of a naive Bayes classifier, to accurately predict the language family that a piece of text belongs to, combined with a lexicon based classifier to distinguish the specific South African language that the text is written in. This approach leads to a 31% reduction in the language detection error. In the spirit of reproducible research the training and testing datasets as well as the code are published on github. Hopefully it will be useful to create a text language identification shared task for South African languages.Comment: Accepted to appear in the proceedings of The 28th Annual Symposium of the Pattern Recognition Association of South Africa, 201

A theoretical investigation in heterogeneous gold catalysis

Includes bibliographical references.Despite the nobleness of bulk gold metal in air, small supported gold particles have been shown experimentally to be active in a wide range of chemical reactions. The objective of this work was to study, theoretically, some of the fundamental aspects of the reactivity of gold catalysts. Using activation of CO, CO2 and H2 as a test case, periodic and cluster density functional theory (DFT) calculations, within the generalized-gradient approximation (GGA), were performed to investigate the change in nobility of gold from the extended surface to small clusters. Potential methanol synthesis intermediates were optimized on the Au(111) surface. It was found that the molecules that are stable as gasphase species generally adsorbed weakly on the surface. Surface hydrogenation of CO-derived species appeared to be easier than surface hydrogenation of CO2- derived species. On an AU13 cluster, the energetics of CO2 adsorption and hydrogenation remain unfavourable. The cluster-size dependency of hydrogen and carbon monoxide adsorption was investigated. It was found that small gold clusters (1 to 13 atoms in size) can bind both H and CO strongly. Due to the changes in the orbital spatial symmetries and the energies of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) with cluster size in this small size range, the adsorption energies depend very strongly on the number of gold atoms present, i.e. each atom makes a difference. For H adsorption, there is a very marked oscillation in adsorption energies, with the clusters with an odd number of gold atoms (with lower LUMO energies) being generally more reactive than the even clusters, up to about 10 atoms when the HOMO-LUMO gap ceases to fluctuate strongly. The role of the support material in activating gold atoms was studied. A hybrid quantum mechanics/molecular mechanics (QMlMM) electronic embedding technique was employed to model the ZnO(000l) surface of zincite. The QM region of the surface, treated by density functional theory, consisted of a total of 13 zinc and oxygen atoms for the zinc-vacant site, and 14 atoms for the bulk-terminated island site. It was found that Au0 and Au+ could be stabilized at the zinc vacant site of this surface. The higher oxidation states are unstable with respect to auto-reduction by the ZnO surface (i.e. their LUMO energies were below the HOMO of a bare ZnO surface. However, gold hydroxyls, where gold has + 1 to +3 oxidation states, can be stabilized at the vacancy. As zinc-substitutional impurities on the bulk-terminated island site, Au+, Au2+ and Au3+ oxidation states can be stabilized. CO was used as a test molecule to probe the chemical reactivity of the gold atoms in different adsorption sites and oxidation states. It was found that supported Au+ was more reactive than Au0, Au2+, or Au3+. Furthermore, CO binds more strongly to supported Au0 than the free Au0 atom. This implies that the support does not simply disperse gold particles, but it also modifies their electronic properties. It was also found that the nucleation of gold atoms to clusters can be affected by the support. Supported charges Au clusters have shorter Au-Au distances than their gas-phase counterparts

A density functional theory study of methanol synthesis catalysed by gold

Bibliography: leaves 59-68

Stains inner: the lived experience, creative practice and changing body consciousness in HIV and AIDS

Thesis (M.A.)--University of the Witwatersrand, Faculty of Humantities, Dramatic Arts, 2012This creative practice-based research report explores a phenomenological approach to the body as a sensorially, audibly, visibly and viscerally present entity. The research argues for an experience of embodiment that highlights the primacy of the body within the context of the HIV and AIDS pandemic in South Africa. It addresses theoretical and methodological concerns of theatre making as a creative practice for interrogating the body’s lived experience of HIV and AIDS. The study argues that theatre has tended to describe the surface experience of the trauma of HIV and AIDS and that it has failed to speak to the lived body experience of HIV and AIDS. In so doing, this report excavates the innovation of a theatre making process that helps illuminate complex human experience through performance. This research report is written in a way that allows the reader access to the process that was developed by the researcher/theatre maker/writer. Through a facilitated process of theatre making, this study focuses on the four co-researchers/performers lived experiences of HIV and AIDS and how through the use of stimuli (visual art and elements of nature) and the use of the combination of somatic play, movement and sound, they evoked and exhumed their bodies living memory. The accounts that were made in the exploration are presented in this report and in the performance and recording (DVD) of Stains Inner. This research posits the body as a knowing entity in the era of HIV and AIDS in South Africa and highlights the process of on-flow in theatre making as a fluid dynamic process through which the body can viscerally access the latent lived experiences associated with the pandemic. It is a powerful process that enhances the body aesthetic in theatre. The study concludes that this form of theatre making has the capacity to create a transformative experience for the performer and audience. The study also puts forth recommendations that would possibly shift the landscape of HIV and AIDS discourse

Reading support for grade 3 learners in full-service schools, Gauteng

In South Africa, the issue of learners reading below their grade level is of great concern. In order to overcome this problem, the Department of Education made it possible that learners be taught to read early in Grade 1. However, despite the learners being taught to learn to read at an early stage, numerous studies have revealed that most of the learners, including those in Grade 3, are still experiencing reading problems. The purpose of this study is to explore how Grade 3 teachers support learners who experience reading problems in Full-service schools. Full-service schools are mainstream schools that were transformed to attend to the underlying inclusive principles and to provide quality education to all learners. In this study, a qualitative approach was used to collect data at the Tshwane North District in the Gauteng Province. The interview questions were piloted with one of the Grade 3 class teachers from a neighbouring full-service school. Then after the pilot study, eleven Grade 3 class teachers and six Learner Support Teachers from three identified full-service schools were interviewed and observed in their classroom while supporting learners experiencing reading problems. The documents that they used were also analysed. To analyse the empirical data an inductive approach and the method for analysing data suggested by Creswell (2000) was followed. The findings revealed that teachers who participated in this study followed a more prescriptive approach of supporting learners who were experiencing reading problems. Furthermore, the findings revealed they used different reading strategies and reading methods even though there were some challenges that hampered the implementation of the support. The issue of differentiating and adapting the reading support to suit the diverse reading needs of learners arose from the study. This was due to the fact that most of the teachers were not trained to adapt the reading support based on the reading needs of the learners. Based on the findings, recommendations were made, and guidelines to draw up an effective reading support based on an integrated approach for Grade 3 learners who experience reading problems in full-service schools was developed. The guidelines combined two theories that underpinned the study, namely, Bronfenbrenner’s ecological systems theory and Vygotsky’s sociocultural theory. The researcher concluded that learners’ improvement in terms of their reading abilities relies on how teachers provided support to them. Hence it is important for teachers to be equipped with sufficient skills and knowledge to provide individualised reading support to learners experiencing reading problems.Inclusive EducationPh. D. (Inclusive Education

Reading problems in the Intermediate Phase: Grade 4 teachers’ opinions

Reading is currently a matter of great concern in South Africa where most learners including Grade 4 learners are reading below their grade level. The research project discussed in this article investigated Grade 4 teachers’ perceptions of teaching learners to read. Teachers’ perceptions could influence their attitude to reading and the ways in which they would teach reading. Bronfenbrenner’s ecological system theory and qualitative research design were used in the study. Seven Grade 4 teachers, among whom was the teacher used in the pilot study, were interviewed and observed while teaching reading in the classroom to gain first-hand understanding of how reading is taught in English as the home language in Grade 4. For some of the learners English was, however, the first additional language. The findings of the study revealed that the teachers understood what reading is; and also the importance of teaching reading. It was, however, noted that not all the Grade 4 teachers were trained in how to teach reading. Although the teachers who took part in the study used different approaches to teach reading, not all of them were in a position to use a combined approach. The grade 4 teachers aired their concerns about the increase in the number of learning areas the learners had to study on entering Grade 4. They also raised their concerns about the lack of support they get from district officials. In the opinion of the teachers the parents were also insufficiently involved in the lives of their children.Keywords: reading in home language, reading problems, Grade 4 learners, training of Grade 4 teacher

Detection and clustering of an Neutral Section faults using machine learning techniques for SMART railways

Abstract: Fault detection and diagnosis plays an important role particularly in railways were abnormal events are detected and a detailed root causes analysis is performed to prevent similar occurrence. The current method used to detect immediate and long-term faults is through foot inspections and inspection trolleys fitted with cameras proving to be inefficient and time consuming when analyzing the data. This paper examines the smart fault detection system on the overhead wires by applying machine learning techniques for accurate assessment of the neutral section before and after failure thereby grouping the events into fault bins. Modern computational intelligence has enabled the fault diagnostic and fault detection to be accurate from the data generated from the sensors. The interaction between the pantograph and contact wire will be monitored using accelerometers and non-contact infrared thermometer sensors were should there be a deviation from the normal signal spectrum it will be detected. The measured data from onsite will be conveyed to ThingSpeak for cloud computation thereby providing notifications in real-time which allows the end user to visualize, analyze and act on data online. A prototype has been built and tested which shows that the system works reasonably with data collected from sensors

Assessment of environmental impacts of urban housing informality on residents : experiences with water, sanitation and waste management in Alexander township

Abstract: The need to protect and preserve urban environments can never be emphasised enough given the essential role cities in general and housing in particular play in the people’s lives be it physically, economically or socially. Although numerous studies have been conducted on informal settlements, particularly their causes, prevalence and general conditions, very little is understood about the impact of water, sanitation and solid waste conditions on residents. Interestingly, the struggles people face on a daily basis as they make efforts to access water, sanitation and waste management services are not well documented. This work therefore explored in detail the nature of relationships that are forged by service providers, the level of service provision and daily experiences of the residents of Alexandra. A case study research design and a qualitative research approach were adopted and applied to gather relevant and meaningful data using interviews of key stakeholders and the residents. The work extended the frontiers of existing knowledge by bringing to the fore new insights on the direct impact of poor state of water supply, deplorable sanitation and glaring inadequacies in municipal solid waste management on residents. First, temporary water storage facilities such as drums and buckets; a mechanism to respond to water supply challenges; results in small particles being formed at the bottom of the facility and if consumed they result in water-borne diseases. Second, the use of pit latrines and the bucket system as a response to poor sanitation in Alexandra has given rise to outbreaks of diseases that are related and caused directly by lack of proper sanitation. Third, the absence of waste disposal facilities and the erratic nature of waste collection services have forced residents to use open pits in their yards to dispose waste or have resorted to open fire burning of waste thus exposing residents..

Tribute to President Nelson Mandela : Hero of heroes

Abstract: Please refer to full text to view abstract

A study into intelligent Neutral Section fault monitoring system on the Coal line using wireless sensor networks

Abstract: Machine learning a subdivision of artificial intelligence which is popular nowadays particularly where large amounts of data are to be evaluated unsupervised by applying algorithms thereby requiring less human effort to process the measurements. This paper presents an intelligent fault monitoring on the overhead wires using wireless sensor network (WSN). The current method used to monitor failures requires both foot patrols and vehicle measurements using cameras, however these methods are both labour and time intensive in preparing and analysing the data from the inspections. An intelligent method is proposed to reduce the amount of time spent on labour intensive inspections through data aggregation and machine learning. Ma-chine learning offers additional flexibility for identifying the type of the faults, finding otherwise hidden pat-terns and grouping instances of events accordingly based on similarities. WSN will convey the measured data to the cloud via the router for computation thereby providing notifications in real-time and also the data can be viewed anywhere by the operator. K-means clustering algorithm will then be applied later using sensors data via Matlab/Simulink