UWCScholar :: Browsing by Author "Venter, Isabella"

Browsing by Author "Venter, Isabella"

Now showing 1 - 12 of 12

A Comparison of Machine Learning Techniques for Facial Expression Recognition
(University of the Western Cape, 2018) Deaney, Mogammat Waleed; Venter, Isabella
A machine translation system that can convert South African Sign Language (SASL) video to audio or text and vice versa would be bene cial to people who use SASL to communicate. Five fundamental parameters are associated with sign language gestures, these are: hand location; hand orientation; hand shape; hand movement and facial expressions. The aim of this research is to recognise facial expressions and to compare both feature descriptors and machine learning techniques. This research used the Design Science Research (DSR) methodology. A DSR artefact was built which consisted of two phases. The rst phase compared local binary patterns (LBP), compound local binary patterns (CLBP) and histogram of oriented gradients (HOG) using support vector machines (SVM). The second phase compared the SVM to arti cial neural networks (ANN) and random forests (RF) using the most promising feature descriptor|HOG|from the rst phase. The performance was evaluated in terms of accuracy, robustness to classes, robustness to subjects and ability to generalise on both the Binghamton University 3D facial expression (BU-3DFE) and Cohn Kanade (CK) datasets. The evaluation rst phase showed HOG to be the best feature descriptor followed by CLBP and LBP. The second showed ANN to be the best choice of machine learning technique closely followed by the SVM and RF.
Co-designing a billing system for voice services in rural South Africa: Lessons learned
(ACM, 2014) Rey-Moreno, Carlos; Ufitamahoro, Marie Josee; Venter, Isabella; Tucker, William David
Access to information and communication technologies re- mains una ordable for many in rural areas despite recent progress in providing voice services to remote communities. The sustainability of alternative technical solutions is a chal- lenge, which can be addressed when local knowledge is taken into account during the design process. This research re- ects on the process of co-designing a billing system for voice services provided by a Community Network in rural South Africa. Several payment methods were explored with users and operators of the Community Network, focusing on the legal, nancial, technical and social feasibility - as well as constraints - of each method. Those methods that suited the community's needs were implemented and tested with stakeholders. The process revealed factors embedded in the provision of voice services by traditional voice operators in South Africa that prevent economically poor and illiterate users from fully bene ting from voice services. Solutions to these factors were explored with users and were implemented as a billing system. The system is currently being deployed in a rural South African community. Both the problems experienced and solutions proposed may inform similar ini- tiatives.
Gaming and computer science: Bridging the gender-gap
(University of the Western Cape, 2019) Adams, Saira-Banu; Venter, Isabella
According to the literature, women are still unrepresented in the field of information technology. Although many women study computer science at first year level, the dropout rate for women—before they graduate—is high, and if they graduate many decide neither to continue with their studies nor to work in the field of information technology. Research has shown that women who have been exposed to computing at some point during their school career or early in their lives, tend to be more open to choosing a career in computer science and are in many cases successful at it. The aim of this research is to understand what factors influence women to choose a career within computer science and to consider whether gaming would encourage young women to enter the field. Design Science Research was the methodology employed. It was chosen since an artefact was developed. For each of the five steps of this methodology a different method was chosen to address the research question. Surveys were administered to first year computer science students and both IT high school teachers and computer science honours students were interviewed. Non-computer science students were involved in the participatory design process.
A participatory design for a billing system: A South African case study of a community based telephony system
(ACM, 2014) Ufitamahoro, Marie Josee; Venter, Isabella; Rey-Moreno, Carlos; Tucker, William David
This paper describes the role participatory design can play in developing and implementing an information and communication technology for development project in a rural area. It shows how the process of co-designing an artifact can reflect and shape social development. A case study was conducted in the Mankosi Community in the Eastern Cape with the aim of designing and implementing a billing system for an existing community-owned telephony system, by accommodating the community’s requirements. Relevant criteria had to be considered for this telephony system based on voice over Internet Protocol with the possibility of ‘break-out’ calls to external networks. Different payment modalities were explored that would allow for a transparent method of both collecting money and applying the collected funds to achieve the project’s sustainability. A participative methodology with future users and operators of the network—using scenarios and prototypes to illustrate the implementation—informed the design of the billing system. Data was collected by means of unstructured interviews and focus group discussions. Qualitative data was analyzed using a qualitative content analysis tool. The community indicated that a billing system, based on both vouchers and prepaid service, would satisfy their needs.
Performance estimation of wireless networks using traffic generation and monitoring on a mobile device.
(University of the Western Cape, 2015) Tiemeni, Ghislaine Livie Ngangom; Venter, Isabella; Tucker, William
In this study, a traffic generator software package namely MTGawn was developed to run packet generation and evaluation on a mobile device. The call generating software system is able to: simulate voice over Internet protocol calls as well as user datagram protocol and transmission control protocol between mobile phones over a wireless network and analyse network data similar to computer-based network monitoring tools such as Iperf and D-ITG but is self-contained on a mobile device. This entailed porting a ‘stripped down’ version of a packet generation and monitoring system with functionality as found in open source tools for a mobile platform. This mobile system is able to generate and monitor traffic over any network interface on a mobile device, and calculate the standard quality of service metrics. The tool was compared to a computer–based tool namely distributed Internet traffic generator (D-ITG) in the same environment and, in most cases, MTGawn reported comparable results to D-ITG. The important motivation for this software was to ease feasibility testing and monitoring in the field by using an affordable and rechargeable technology such as a mobile device. The system was tested in a testbed and can be used in rural areas where a mobile device is more suitable than a PC or laptop. The main challenge was to port and adapt an open source packet generator to an Android platform and to provide a suitable touchscreen interface for the tool. ACM Categories and Subject Descriptors B.8 [PERFORMANCE AND RELIABILITY] B.8.2 [Performance Analysis and Design Aids] C.4 [PERFORMANCE OF SYSTEMS] Measurement techniques, Performance attributes
Performance Evaluation of a Wireless Network using a VoIP Traffic Generator on a Mobile Device
(ACM, 2014) Tiemeni, Ghislaine Livie Ngangom; Venter, Isabella; Tucker, William David
The problem of generating different patterns of traffic to emulate real user behaviour is receiving considerable attention with the construction of new and more complex network architectures. The theoretical modelling of waveforms or signals that flow through networks is valuable in a variety of scenarios including performance analysis and the design of communication systems. In the literature, many computer-based performance evaluation tools have been discussed. However, these tools lack the ability to run on affordable technologies such as mobile phones. The fundamental contribution of this work is the design of a traffic generating tool called MTGawn which is able to run on a mobile device. Design Science Research was the research methodology used for the design and deployment of a prototype of the proposed system. VoIP traffic was emulated using an implementation of well-known real time transport protocols such as RTP and cRTP, and parameterization was defined by using three codecs namely: G.711, G.723, and G.729. An evaluation was performed in a laboratory wireless network testbed and preliminary results were collected and analysed. The results of the experiments show that such a measuring instrument can be deployed on a mobile phone. More experiments are being done to ensure the accuracy of the data and also to compare the results with that of computer-based systems. Furthermore additional functionalities, similar to the functionality found on the computer-based open source tools, are being added to the mobile tool.
Rural Wireless Mesh Network Analysis on Mobile Devices
(Telkom SA, 2014) Tiemeni, Ghislaine Livie Ngangom; Venter, Isabella; Tucker, William David
The aim of this research effort is to build an efficient and accurate mobile traffic generator based on open source computer-based traffic generator software. A high performance mobile traffic generator would make the evaluation of the quality of networks, deployed in remote areas, simpler. The motivation for this software is to ease feasibility testing and monitoring in the field particularly in rural areas by using affordable and lightweight technology such as a mobile device. Furthermore, a mobile system is more suitable than a personal computer (PC) or laptop in a rural area where the deployment of computers is difficult and impractical. To conduct the research, both an experimental and a simulation research methodology will be applied and the method of investigation will combine methods such as laboratory experiments, document analysis and a literature survey.
Smartphone owners need security advice. How can we ensure they get it?
(CONF-IRM and AIS Electronic Library (AISeL), 2016) Renaud, Karen; Blignaut, Renette; Venter, Isabella
Computer users often behave insecurely, and do not take the precautions they ought to. One reads almost daily about people not protecting their devices, not making backups and falling for phishing messages. This impacts all of society since people increasingly carry a computer in their pockets: their smartphones. It could be that smartphone owners simply do not know enough about security threats or precautions. To address this, many official bodies publish advice online. For such a broadcast-type educational approach to work, two assumptions must be satisfied. The first is that people will deliberately seek out security-related information and the second is that they will consult official sources to satisfy their information needs. Assumptions such as these ought to be verified, especially with the numbers of cyber attacks on the rise. It was decided to explore the validity of these assumptions by surveying students at a South African university, including both Computer Science and Non-Computer Science students. The intention was to explore levels of awareness of Smartphone security practice, the sources of advice the students used, and the impact of a Computer Science education on awareness and information seeking behaviours. Awareness, it was found, was variable across the board but poorer amongst students without a formal computing education. Moreover, it became clear that students often found Facebook more helpful than public media, in terms of obtaining security advice.
South African Sign Language Hand Shape and Orientation Recognition on Mobile Devices Using Deep Learning
(University of the Western Cape, 2017) Jacobs, Kurt; Ghaziasgar, Mehrdad; Venter, Isabella; Dodds, Reginald
In order to classify South African Sign Language as a signed gesture, five fundamental parameters need to be considered. These five parameters to be considered are: hand shape, hand orientation, hand motion, hand location and facial expressions. The research in this thesis will utilise Deep Learning techniques, specifically Convolutional Neural Networks, to recognise hand shapes in various hand orientations. The research will focus on two of the five fundamental parameters, i.e., recognising six South African Sign Language hand shapes for each of five different hand orientations. These hand shape and orientation combinations will be recognised by means of a video stream captured on a mobile device. The efficacy of Convolutional Neural Network for gesture recognition will be judged with respect to its classification accuracy and classification speed in both a desktop and embedded context. The research methodology employed to carry out the research was Design Science Research. Design Science Research refers to a set of analytical techniques and perspectives for performing research in the field of Information Systems and Computer Science. Design Science Research necessitates the design of an artefact and the analysis thereof in order to better understand its behaviour in the context of Information Systems or Computer Science.
Understanding stakeholder expectations in higher education
(CONF-IRM, 2017) Bytheway, Andrew J.; Venter, Isabella; Whyte, Grafton
Higher education invests heavily in information technology and information systems, with variable outcomes. Organisations in other sectors, such as engineering, the defence industry, public administration and business, have developed and adopted good practice for the choice, development and operation of software-based systems that are only sometimes understood in higher education. In order to assess the extent to which good practice might assist higher education, the four tertiary institutions in the Western Cape of South Africa were approached and a representative range of academic, administrative, technical and managerial respondents agreed to contribute to the study. Interviews were organised in two parts: the first an open conversation about their involvement with systems, and the second a structured examination of systems-related events that they considered significant. By inspection of those events, bipolar scales were developed by which respondents were able to characterise events (for example as ‘challenging’ or ‘easy’, or as ‘functional’ or ‘dysfunctional’). Respondents rated events on those scales. Repertory Grid analysis was applied so as to investigate which scales correlated with event success. 30 scales (out of 170) proved to be adequately correlated with success, and by principal component analysis they were combined to form ten ‘success scale’ groups, indicating ten areas where the deployment of good practice might be expected to lead to more effective use of improved information systems. A new Reference Model is developed that has a role to play in resolving the transitions between the domains of the Information Management Body of Knowledge (IMBOK).
Understanding the factors that influence trust in e-services: a case study of a wireless mesh network implementation in Mankosi, South Africa
(University of the Western Cape, 2014) Ufitamahoro, Marie Josée; Venter, Isabella; Tucker, William
This thesis deals with the design of a business model for rural telephony based on a wireless mesh network for a rural community, the Mankosi community, located in the Eastern Cape Province of South Africa. Its aim is to understand the social, economic and technical issues that are involved in the adoption of information and communication technologies for development and how they relates to trust in e-services. Externally funded projects tend to be expensive and are often unsustainable once the external funding ceases. The cost of a mesh network (once implemented) is almost negligible, apart from its maintenance. The pillars of the project are sustainability and community ownership, and the aim was to design the wireless mesh network, provide telephony service to the community and use solar power to charge mobile phones. The community leaders of Mankosi indicated that they do not want the service to be completely free, but would charge a small fee for each call in order to generate the funds needed for the maintenance of the system. In order to do so, a prototype billing system was configured and adapted to the needs and expectations of the community. The principles and steps of soft systems methodology were used to manage the research process of this case study. This methodology was a powerful tool to carry out the research and address the research problem in a participative way with the stakeholders. The participatory design process used in the design phase of the project had the added advantage that the community understood the purpose of the network, and since they contributed to its design, they felt that they owned it and could trust its billing system. A further benefit was that a core group of participants were committed to the project and felt that the overall quality of community members' lives would be improved by it and similar projects. The process contributed to the personal development of the participants by giving the community a voice and sense of power – the ability to change things – and it vastly expanded community members’ vision of what they are capable of. It was found that the current means of communication, i.e. using mobile phones, is expensive for local users in relation to their average income. The proposed billing system – designed with the help of the community – will be trusted by the community and provide Mankosi with a low-cost communication system by making use of the existing experimental mesh network. The community will be able to sustain their network with the income generated. The network will in future provide access to the Internet and will be able to handle breakout calls to external networks.
Voice signature based Speaker Recognition
(University of the Western Cape, 2017) Alkilani, Menia Mohamed; Venter, Isabella
Personal identification and the protection of data are important issues because of the ubiquitousness of computing and these havethus become interesting areas of research in the field of computer science. Previously people have used a variety of ways to identify an individual and protect themselves, their property and their information.

Browsing by Author "Venter, Isabella"

Results Per Page

Sort Options