Masters of Science / This thesis investigates the use of mobile phones as service-delivery devices in a sign language machine translation system. Four sign language visualization methods were evaluated on mobile phones. Three of the methods were synthetic sign language visualization methods. Three factors were considered: the intelligibility of sign language, as rendered by the method; the power consumption; and the bandwidth usage associated with each method. The average intelligibility rate was 65%, with some methods achieving intelligibility rates of up to 92%. The average size was 162 KB and, on average, the power consumption increased to 180% of the idle state, across all methods. This research forms part of the Integration of Signed and Verbal Communication: South African Sign Language Recognition and Animation (SASL) project at the University of the Western Cape and serves as an integration platform for the group's research. In order to perform this research a machine translation system that uses mobile phones as service-delivery devices was developed as well as a 3D Avatar for mobile phones. It was concluded that mobile phones are suitable service-delivery platforms for sign language machine translation systems. / South Africa

Dissertation submitted in compliance with the requirements for the Masters Degree in Technology: Business Administration, 2008. / The aim of the study was to identify causes of churning, to find ways of managing it and to diagnose customers‟ communication needs. Furthermore the research tested the impact of messaging services on customer retention and whether these services could compensate for the declining revenue or become new cash cows for service providers. The units of analyses were young people of ages ranging from 15 to 24. This group was chosen because it was found, during the study, that they used new services more often than any other age group. The initial plan, however, was to interview the entire population of cellphone users. Stratified random sampling was used to randomly select the units of analysis. Interviews were conducted at the homes of respondents, in the streets and at a shopping centre. Causes of customer churning were found to be billing by service providers that confused customers and „better phone deals offered by the competitors‟ resulting in some of the respondents switching providers. Other aspects about which respondents complained and which therefore could cause churning are „poor network quality‟, „confusing pricing structure‟ and „long waiting on customer care line‟. The respondents indicated that their communication needs could be satisfied by services that are easy to use, a helpful customer care agent and being able to retain a number when switching a service provider. Therefore churning could be managed by removing or reducing the causes of it and attracting the customers by meeting their communications needs, which are, improving customer care service and designing services that are easy to use. The research was inconclusive on the messaging services. Of the three new messaging services that were studied, only one was extremely popular, while the other two were hardly used. Instant messaging was the second most used service to voice and SMS and it was also ranked second, in order of importance. The other two messaging services, mobile email and MMS, received low rankings from the respondents. In addition more than a quarter (27%) of the respondents had never used mobile email. The implications of these findings are that service providers should improve their customer care service and design services that are easy to use.

Thesis (MBA)--Stellenbosch University, 2008. / ENGLISH ABSTRACT: Telecommunication operators are faced with the challenges of rising upward pressure by the competition; this is mainly due to the saturation of subscribers and the aggressive battle for a share of the customer wallet. This has forced mobile network operators to look for new opportunities to drive growth and to cut costs in business operations. The battleground rules are mainly defined by the speed with which new technologies are introduced, customer perception of the quality of the network, and site planning. The purpose of this study is to identify a framework to help the company identify activities which, due to their level and quality of performance, either help or hinder the performance of critical success factors. The starting point for this process is defining the critical success factors based on the company‟s high level priorities. Thereafter, activities that are critical or non-critical, based on their influence on each critical success factor, are identified. Finally, Vodacom‟s operations group activities in a value chain are analysed. The framework is applied to analyse Vodacom‟s operations group activities in a value chain with a view to improve sustainable execution of critical success factors. The report concludes with a decision to outsource activities that are non-critical and are being performed poorly, and the strategic outsourcing of those critical activities which require specialised skills easily sourced outside the company instead of Vodacom spending huge amounts of money in attracting and retaining such specialised skills. / AFRIKAANSE OPSOMMING: Telekommunikasie-ondernemings staan voor die uitdaging om toenemende opwaartse druk van hul mededingers doeltreffend aan te spreek, hoofsaaklik as gevolg van die oorversadigde intekenaarmark en die agressiewe stryd om 'n aandeel van die kliënt se beursie. Dit noop selfoonnetwerkondernemings om te soek na nuwe geleenthede om groei te dryf en om die bedryfskostes van die onderneming te besnoei. Die reëls op die gevegsfront word neergelê deur onder andere die tempo waarteen nuwe tegnologie bekend gestel word, die kliënt se persepsie van die netwerkkwaliteit, en terreinbeplanning. Hierdie studie het ten doel om 'n raamwerk te identifiseer wat die onderneming kan gebruik om te help met die identifisering van aktiwiteite wat as gevolg van hul vlak en gehalte van prestasie die kritiese suksesfaktore óf positief óf negatief beïnvloed. Die vertrekpunt in hierdie proses is die bepaling van kritiese suksesfaktore gegrond op die maatskappy se hoë-vlak prioriteite, en daarna moet aktiwiteite wat kritiek of nie-kritiek is op grond van hul invloed op elk van die kritiese suksesfaktore, geïdentifiseer word. Daarna word Vodacom se operasionele groepsaktiwiteie in 'n waarde-ketting ontleed. Die raamwerk word gebruik om Vodacom se operasionele groepsaktiwiteie in 'n waarde-ketting te ontleed met die oog op die verbetering van die volhoubare uitvoering van die kritiese suksesfaktore. Die verslag sluit af met 'n aanbeveling dat nie-kritiese aktiwiteite wat swak verrig word, uitgekontrakteer moet word; en dat ook daardie kritiese aktiwiteite wat gespesialiseerde vaardighede vereis en waarvan daar 'n oorvloed buite die onderneming bestaan, uitgekontrakteer moet word eerder as wat Vodacom groot bedrae geld spandeer aan die werwing en instandhouding van sulke gespesialiseerde vaardighede.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2007. / The work presented in this Thesis relates to the increased capabilities of the mobile Internet and the possible use of cellphones as an enhancement to video surveillance systems. The focus of the Thesis is on the delivery of live video content to Java enabled cellphones. The various characteristics, capabilities and limitations of the mobile networks- and phones are investigated. Various options for streaming video content to cellphones are also explored. The design and implementation of a digital surveillance system with the ability to stream live video to a cellphone is presented. Two versions of the streaming protocol are developed and implemented in cellphone applications, with which the video stream can be viewed. An evaluation and real-life testing of the applications are presented. Recommendations regarding further enhancements are provided.

published_or_final_version / Business Administration / Master / Master of Business Administration

published_or_final_version / Business Administration / Master / Master of Business Administration

D.Phil. / A modern day N-P complete problem is the assigning of frequencies to transmitters in a cellular network in such a manner that, ideally, no two transmitters in the same cell or neighbouring cells use the same frequency. Considering that an average cellular network provider has over 29 000 transmitters and only 55 frequencies, choosing these frequencies in an optimal way is a very difficult computational problem. Swarm intelligence allows the acceptable minimization and optimization of the frequency assignment problem (FAP). Swarm intelligence is a concept modelling the processes in natural systems such as ant colonies, beehives, human immune systems and the human brain. These systems are selforganizational and display high efficiency in the execution of their tasks. A number of simple automated agents interacting with each other and the environment form a collective. Specifically, there is no "central agent" directing the others. A collective can display surprising intelligence which emerges out of the interaction of the individual agents. This collective intelligence, referred to as swarm intelligence, is displayed in ant colonies when ants build elaborate nests, regulate nest temperature and efficiently search for food in very complex environments. In this thesis a proposal is made to utilize swarm intelligence to build a swarm automatic frequency planner (swarm AFP). The swarm AFP produces frequency plans that are better, or on par with existing frequency planning tools, and in a fraction of the time. A swarm AFP is presented through an in-depth investigation into complex adaptive systems, agent architectures and emergence. Based on an understanding of these concepts, a swarm intelligence model called ACEUS is constructed. ACEUS forms the platform of the swarm AFP. It is a contribution to multi-agent technology as it is a new multi-agent framework that exhibits swarm intelligence and complex distributed computation. What differentiates ACEUS from other multi-agent technologies is that ACEUS works on the basis that the tasks or constructions that have been created by the agents actually guide the agents in their endeavours. There is no centralised agent controlling or guiding the process. The agents in ACEUS receive information and stimulation from their tasks or constructions in the environment. As these constructions or tasks alter the environment, the agents receive stimulus from the changing environment and then react to the changing environment. The changing environment acts as an emergent guiding force to the agents. This is the important contribution that stigmergy contributes to ACEUS. Utilizing this concept, ACEUS is used to create a swarm AFP. The swarm AFP is benchmarked against the COST 259 Siemens benchmarks. In all the COST 259 Siemens scenarios the swarm AFP produced the best results in the shortest time. The swarm AFP was also tested in a real cellular network and the resulting statistics before and after the swarm AFP implementation are presented.

The purpose of this research is to determine the linearity and monotonicity of the THS5651IDW digital to analog converter (DAC), a prototype of the future Texas Instruments TLV5651, 10-bit, 125 MHz communication DAC. Testing was conducted at the Texas Instruments facility on Forest Lane, Dallas, Texas. Texas Instruments provided test equipment, software and laboratory space to obtain test data. Analysis of the data found the DAC to be monotonic since the magnitude of the differential nonlinearity (DNL) was less than ± 1 least significant bit (LSB) and the integral nonlinearity (INL) was less than ± 0.5 LSB. The study also showed that the DAC has primarily negative DNL although the DNL is well within the desired specification.

Knowledge in organizations today is considered as one of the most important assets the organization possesses. A considerable part of this knowledge is the knowledge possessed by the individuals employed by the organization. In order for intelligent systems to perform some of the tasks their human counter parts perform in an organization the intelligent systems need to acquire the knowledge their human counter parts possess for the specific task. To develop an intelligent system that can perform a specific task in an organization, the knowledge needed to perform the task will have to be extracted from the individuals in the organization via knowledge acquisition. This knowledge will then be presented so that the intelligent system can understand it and perform the task. In order to develop an intelligent system an ontology representing the domain under consideration as well as the rules that constitute the reasoning behind the intelligent system needs to be developed. In this dissertation a development environment for developing intelligent systems called the Collaborative Ontology Builder for Reasoning and Analysis (COBRA) was developed. COBRA provides a development environment for developing the ontology and rules for an intelligent system. COBRA was used in this study to develop a Cellular telecommunications Network Consistency Checking Intelligent System (CNCCIS), which was implemented in a cellular telecommunications network. / Prof. E.M. Ehlers

The work in this thesis concerns the use of reinforcement learning solutions to re-source allocation problems in channelised cellular networks. The methodology of re-inforcement learning techniques was chosen for application to these problems due to its capability of finding efficient policies in a fully on-line, adaptable manner, without requiring specific environment models. All of the presented agent architectures are assumed to simultaneously learn and perform network control functions in a totally on-line and unsupervised manner, and agents are developed with a view to real-world implementability by focussing on techniques that have low resource requirements and make use of only local system information.