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

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

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

Origen y desarrollo de la obra adventista en la IASD Vitarte Central del distrito misionero de Vitarte “A” entre los años 1950-1990

La historia sobre el origen y desarrollo de la IASD Vitarte Central desde sus inicios en 1950 hasta 1990 es muy significativa para la historia de la IASD en el Perú. A continuación se presentara un breve resumen destacando tres puntos importantes sobre el estudio realizado de la obra adventista en Vitarte: Primero, destacar la importancia de la obra misionera educativa del Complejo Educativo Superior Unión (CESU) en el distrito político de Ate Vitarte a partir del año de 1950. Los proyectos sociales, la obra misionera realizada por Edmundo Alva, Hammerly Dupuy, Angélica Peverini, Luis del Pozo, entre otros; lograron el establecimiento así la primera escuela sabática filial “Hogar Soñado” en 1967. Segundo, la migración de familias adventistas provenientes de Lima y provincias a Ate Vitarte, además de la obra misionera emprendida por el CESU, el liderazgo eclesiástico de los hermanos pioneros de la iglesia, entre otros; fueron factores importantes para la organización de la IASD de Vitarte Central el 19 de diciembre de 1977. Tercero, otra migración importante de familias adventistas a Ate Vitarte, el liderazgo eclesiástico de pastores, ancianos y líderes de iglesia, además del establecimiento de las escuelas sabáticas filiales en la iglesia y su compromiso con la misión de expandir la obra adventista, permitieron que la IASD Vitarte Central se multiplique y alcance así ser distrito misionero el 4 de enero de 1990.LIMAEscuela Profesional de TeologíaInvestigación bíblica-históric

Exploring career information with youth

This study investigates the importance of initiating career exploration discussions with young people from disadvantaged backgrounds, using the developmental-contextual framework of career development by Vondracek, Lerner & Schulenburg (1986). This model stresses the dynamic relationship between an individual, the ever-changing environment and how each influences the other. Based upon an earlier study by Spencer (1999), this study aims to explore the developmental-contextual model as the basis of successive group discussions at a pivotal moment in the lives of the youth from disadvantaged backgrounds. In addition, it aims to understand individuals’ perceptions of career education and the influences on career decision-making and aspiration. Data were collected through setting up and running a focus group session once a week over a period of five weeks, in which different career-related topics were discussed. The sample consisted of nine unemployed students who were currently not in a tertiary institution between the ages of 18-25 years. The findings indicated a noteworthy need for more relevant career interventions to be investigated and implemented for the diverse South African population. The study’s findings demonstrated that individuals might be more open to exploring career development through group rather than individual counselling. It was found that parents are the main career influencers in their children’s lives. Mothers were experienced as role models, supporters and encouragers while fathers were experienced as absent and unsupportive, playing little or no role in their children’s lives. The participants found this form of career exploration appealing as it allowed for peer consultation and the freedom to discuss career issues in a non-judgemental setting