Computer Science
Browse by
The Bridging Application and Network Gaps (BANG) group examines the intersection of human computer interfaces, computer networks and software engineering within the context of ICT interventions in disadvantaged communities.
The South African Sign Language (SASL) group looks at the integration of signed and verbal communication building on the South African Sign Language Translation System.
Collections in this community
Recent Submissions
-
Blake, Edwin H.; Tucker, William D.; Glaser, Meryl; Freudenthal, Adinda (Wiley, 2011)[more][less]
Abstract: The process of community-based co-design is one that explores various solution configurations in a multi-dimensional design space whose axes are the different dimensions of requirements and the various dimensions of designer skills and technological capabilities. The bits of this space that one can ‘see’ are determined by one's knowledge of the user needs and one's own skills. Co-design is a way of exploring that space in a way that alleviates the myopia of one's own viewpoint and bias. As one traverses this space one traces a trajectory according to one’s skills and learning and according to the users’ expressed requirements and their learning. URI: http://hdl.handle.net/10566/844 Files in this item: 1
BlakeDeafTelephony2011.pdf (4.201Mb) -
Wang, Yuan Yuan; Tucker, William D. (Telkom, 2010)[more][less]
Abstract: This paper describes the design and evaluation of two browser-based video communication prototypes that support sign language communication between Deaf people. The research explores combinations of technologies, protocols and architectures with the hope to eventually provide a mobile video system that Deaf people would want to use enough to pay for. Technology products, and in particular mobile and web-based video communication systems, are designed for the majority of people in general. These are not necessarily suitable for Deaf people who have very different physiological and cultural needs. We focus on browser-based video transmission because end-users need not fiddle with application installation. Web-browsers are also common on mobile phones. This paper compares two prototypes built with Adobe Flex and the fifth version of the HyperText Markup Language, H.264 and H.263 video codecs, and PC and mobile phone implementations. The paper describes the motivation, related work, methods, prototype design and finally analyses results of user experiments conducted with Deaf users. URI: http://hdl.handle.net/10566/739 Files in this item: 1
WangTucker-SATNAC 2010.pdf (351.2Kb) -
Mutemwa, Muyowa; Tucker, William D. (Telkom, 2010)[more][less]
Abstract: This paper describes how a deaf to hearing communication aid built for a mobile phone can be used to provide semi-synchronous communication between a Deaf person and a hearing person who cannot sign. Deaf people with access to mobile phones have become accustomed to using Short Messaging Services, to communicate with both hearing and Deaf people. However Most Deaf people have basic literacy levels and hence prefer not to communicate with text, but with South Africa Sign Language. The prototype uses interpreted communication between sign language and English. The mock-up is meant to help a Deaf person convey their medical conditions to a doctor face-to-face in the office. The prototype is made using prerecorded sign language videos for the Deaf person and English text for the hearing doctor. The interaction on the mobile phone is done inside the phone's browser using video streaming, instead of playing the video in a third-party media player. The design goal was to present the system on a mobile phone from the computer-based prototype. This paper takes a look at the background, related systems, the methods, the design and user testing of such a system on a mobile phone; using two prototypes client-server and client only. URI: http://hdl.handle.net/10566/738 Files in this item: 1
MutemwaTucker-SATNAC2010.pdf (726.7Kb) -
Chitedze, Zimani; Tucker, William D. (Telkom, 2011)[more][less]
Abstract: This paper addresses mobility management issues in an environment with both wireless LAN and wireless mesh networks. We first examine wireless mesh network client side transparency within mesh mobility management protocols and then look at standard mobility management protocols. The client side transparency scheme enables mobile nodes to support mobility in heterogeneous and homogeneous networks. However, they are not necessarily compatible with mobile IP protocols. Although a typical mesh topology tends to be an unplanned graph and routes change dynamically, standard mobility management protocols such as MIPv6, HMIPv6, and FMIPv6 may be used for mobility management in wireless mesh networks. To learn how MIPv6 operates, we used the OPNET 16.0 MIPv6 model to simulate a heterogeneous wireless environment comprising both WLAN and WMN. The simulation results show that MIPv6 is able to manage vertical handover between WLAN and WMN. However, in our opinion, its performance with both route optimization and tunneled traffic mechanisms is not effective enough. MIPv6 suffers from handover latency and packet loss which can combine to compromise delaysensitive applications such as video conferencing. URI: http://hdl.handle.net/10566/700 Files in this item: 1
ChitedzeTucker-SATNAC2011.pdf (1.301Mb) -
Kobo, Hlabishi Isaac; Tucker, William D.; Liu, Xiao Ming (Telkom, 2011)[more][less]
Abstract: Situation-aware routing seeks to improve quality of service on hybrid wireless mesh networks by making routing decisions based on the current situation of the network. BATMAN-adv is a mesh routing protocol that counts beacons as a link quality metric. We modified BATMAN-adv to give more recently received beacons more weight, thereby giving a more precise indication of the current state of a link. We then compared the original protocol with our modification in a small laboratory test bed. Results show little relation between jitter and packet loss. Jitter is, however, proportional to throughput. The average throughput achieved on both protocols was almost the same but we noticed that the throughput on our modified version increases as the network grows. Our protocol modification suffered from packet loss at low bandwidth rates but this reduces as the transfer rate increases and buffer size shrinks. We conclude that our situationaware protocol modification shows potential to address issues pertaining to scalable and congested static mesh networks with mobile nodes. URI: http://hdl.handle.net/10566/699 Files in this item: 1
KoboTuckerLiu-SATNAC2011.pdf (446.4Kb)