M.Sc.(Computer Science) / Agent technology has become more common in mainstream applications as it allows systems to perform routine operations without input from human users. The current evolution of the internet and the increasingly distributed nature of commercial interests, such as bidding auctions, personal shopping assistants and corporate management systems, require software in a distributed environment to be capable of acting autonomously. Multi-agent systems have emerged to deal with these distributed environments which can range in size from a couple of agents to potentially infinite agents [Vla03, Rus03]. When considering a cooperative multi-agent system, it is important for agents to coordinate effectively. Strategic game theory has introduced a means to coordinate by providing social conventions and roles [Vla03]. Both social conventions and roles help simplify the coordination problem between agents when performing coordination actions. An additional simplification of the coordination problem is to utilise coordination graphs. This reduces the number of agents in the environment to consider for a coordination action [Gue02]. Communication in multi-agent systems extends the ability of agents to coordinate with one another. It allows the removal of the requirement to determine the state of participating agents by inspection. Instead, an agent could request the state of another agent by utilising a communication action. Communication does require an additional level of management since agents are rarely allowed to communicate freely and the communication language is not always guaranteed to be standard between agents [Cha02, Vla03]. The dissertation covers the background information regarding multi-agent systems and focuses on the elements that are unique to these systems, such as coordination, communication and methods to represent knowledge structures in a multi-agent system. A model is then proposed as a framework in which scalable populations of agents are able to coordinate when limited knowledge is available about other agents in the environment. The model, which is called the Controller Operator Graph (COG) model, introduces two unique agent types which help coordinate a large population of agents. The unique agents are provided to assist with communication and coordination in the COG model. The COG model is designed to help agents coordinate in a dynamic environment by providing mechanisms to monitor agent population and goal states. The operator agent is responsible for maintaining communication links between agents and provides the ability to monitor a population of agents for the multi-agent system. The controller agent is responsible for ensuring that coordination actions are performed between agents which have no prior knowledge of one another. It provides a means to handle a dynamic situation in which the coordination actions can be extended beyond the original requirements. An implementation of the COG model is provided utilising a supply chain scenario which compares increasing agent populations. The COG implementation demonstrates by means of unified modelling language diagrams a method to design and develop the different concepts in the COG model, such as the execution tree, controller agent and operator agent. The implementation demonstrates the strengths of the COG model, which are handling dynamic environments and achieving dynamic goal states for the environment. The implementation also indicates some of the weaknesses in the COG model, such as greedy agent selection by the controller agent, and single points of failure.

In the past three decades, linear time-invariant (LTI) control design techniques have been developed which can achieve stringent performance specifications in the presence of process uncertainties. However, all such LTI techniques are limited by the Bode gain-phase relation. Specifically, an LTI controller's high-frequency magnitude can not be designed arbitrarily but depends on the low-frequency specifications and stability constraints. Qualitatively speaking, "large" low-frequency magnitudes have to go with "large" high-frequency magnitudes, which make the closed-loop system more sensitive to sensor noise and high-frequency modeling errors. This phenomenon is called "cost of feedback", for which LTI control theory can not offer a remedy. In this dissertation, a reset control design method is studied, which is based on ideas originated in the 1950's. The nonlinear controller is composed of a reset network, whose states are reset to zero when its input crosses zero, cascaded with a linear network. Using describing function analysis, the low-frequency performance of this nonlinear system is similar to that of a linear system where the resetting mechanism is not used. However, the control bandwidth is reduced, thereby reducing the "cost of feedback" beyond the limitation imposed by the LTI system's gain-phase relation. In this research, a theoretical framework for the reset control systems is developed, which has connection with the recently developed framework for systems with impulse effects. In this framework, the uniform exponential stability and uniform bounded-input-bounded-output stability for reset control systems are studied and a small-gain stability condition is derived. An optimal matrix norm search algorithm is developed to sharpen this small-gain condition. Based on these theoretical study, a set of engineering design guidelines for reset control are developed and are applied to a tape-drive servo control system. The simulations and experiments of the reset control for this tape-drive servo control system show the potential of the reset control design.

The purpose of this study was to identify the main concern of jobseekers and recruitment agencies in electronic recruitment (e-recruitment) and determine how it was resolved. The country of Namibia was chosen for the study because many of its jobseekers and recruitment agencies are adopting e-recruitment to overcome challenges in their recruitment context. In order to meet the purpose of the study, Classic Grounded Theory Methodology (classic-GTM) was used. Through the application of classic-GTM it emerged that jobseekers' and recruitment agencies' perspectives on e-recruitment are varied and shifting, which together with the dynamics in information technology bring many possibilities and fluidity of stakeholders' behaviour. Therefore, jobseekers and recruitment agencies are mainly concerned about Fit or lack thereof between their conceptualizations of Objects of Concern (namely information technology, jobseekers, job providers (recruitment agencies and employers) and jobs) in such a dynamic environment. Pursuing Fit emerged as the core variable (core category) representing how the participants continuously resolved their main concern. Two sub-categories constituting Pursuing Fit are Interpreting Fit and Positioning for Fit and they explain how stakeholders interpret e-recruitment concepts and position themselves and other Objects of Concern based on interpretation. Recruitment is likely to take place when Objects of Concern relate in a desirable (fitting) manner. The study's contribution to knowledge is through the theory of Pursuing Fit that suggests a systematic way of understanding e-recruitment and of conceptualizing information technology in e-recruitment to increase chances of recruitment. Implications common for both jobseekers and recruitment agencies are context awareness and flexibility. Context awareness allows stakeholders to interpret Objects of Concern based on the context and flexibility makes it possible to change from a previously held position. The study can be used as the foundation for research involving multiple stakeholders in e-recruitment. In conclusion, e-recruitment is a process of meaning creation in which stakeholders interpret concepts and based on the meanings relate the concepts with each other.

Partial differential equations (PDEs) model nearly all of the physical systems and processes of interest to scientists and engineers. The analysis of PDEs has had a tremendous impact on society by enabling our understanding of thermal, electrical, fluidic and mechanical processes. However, the study of PDEs is often approached with methods that do not allow for rigorous guarantees that a system satisfies complex design objectives. In contrast, formal methods have recently been developed to allow the formal statement of specifications, while also developing analysis techniques that can guarantee their satisfaction by design. In this dissertation new design methodologies are introduced that enable the systematic creation of structures whose mechanical properties, shape and functionality can be time-varying. A formal methods formulation and solution to the tunable fields problem is first introduced, where a prescribed time evolution of the displacement field for different spatial regions of the structure is to be achieved using boundary control inputs. A spatial and temporal logic is defined that allows the specification of interesting properties in a user-friendly fashion and can provide a satisfaction score for the designed inputs. This score is used to formulate an optimization procedure based on Mixed Integer Programming (MIP) to find the best design. In the second part, a sampling based assumption mining algorithm is introduced, which is the first step towards a divide and conquer strategy to solve the tunable fields problem using assume-guarantee contracts. The algorithm produces a temporal logic formula that represents initial conditions and external inputs of a system that satisfy a goal given as a temporal logic formula over its state. An online supervised learning algorithm is presented, based on decision tree learning, that is used to produce a temporal logic formula from assumption samples. The third part focuses on the tunable constitutive properties problem, where the goal is to create structures satisfying a stress-strain response by designing their geometry. The goal is represented as a logic formula that captures the allowed deviation from a reference and provides a satisfaction score. An optimization procedure is used to obtain the best geometric design.

We have problem areas which are beyond the scope of a discipline, but we are generally educated in just a single discipline. I explored our philosophy of work to see how we became disciplinary, where the disciplines came from, what philosophy underlies our way of working, and what philosophy underpins work that is beyond the scope of a discipline. The underlying philosophy leads to the research question. My hypothesis is that a systems engineer can create a model which networks the disciplines using constructs from philosophy, the tiers of disciplines in transdisciplinarity, and systemic and holistic thinking. This will provide a way of working on problem situations which transgress the boundary of a discipline. Using constructs from philosophy, the methods of the philosophers, hermeneutics, systems thinking and soft systems methodology I proceeded to create a conceptual model and showed conceptual examples of how to use the model. The client for the model is the interdisciplinary researcher who is seeking a way of working to manage problem areas that transgress disciplinary boundaries. The recommendation is made for using critical, systemic and holistic thinking and a network model of disciplines to manage our approach to problem situations which are beyond the scope of a discipline. The model is developed in the incremental sequence: disciplinary, multidisciplinary, interdisciplinary, transdisciplinary and gets as far as catering for tiers of disciplines (one aspect of the large and complex field of transdisciplinarity). Therefore, the model is suitable for interdisciplinary research, but can be developed further in future projects. The importance of the model is that it provides a practical way of working to manage problem situations which transgress disciplinary boundaries whilst accessing the expertise of disciplined practitioners. The model can find wide applicability. It is not necessary for the user of the model to be comfortable with the abstract philosophy used to create it. Users will need the will for uncoerced mutual understanding or free communication, along with their disciplinary expertise. The reader of the dissertation however should be comfortable with abstractions such as ideas about reality and actuality, form and class, subject and object, truth and justice, truthfulness and functional fit. Future work may reduce the method to practice in the academy and extend the method to bridging silos in learning organisations in the workplace. The work was conducted independently, and an original model was created.

Includes bibliographical references (leaves 118-122). / IT investments constitute a major portion of the capital budgets of many organizations. It can be challenging to select the right projects that fit the corporate strategy to maximize value for the organization. In the past, senior executives focused on projects that met three criteria, namely being on-time, on budget and in scope. However, a shift has occurred as a result of the fact that senior executives are more concerned about the right mix of projects that will best utilise the organization's resources and deliver long-range growth. Some of the benefits of IT Project Portfolio Management (IT PPM) are to provide executives with the ability to monitor projects ensure business alignment and identify risks quickly. It is argued that maintaining a balanced portfolio of diverse projects can reduce the risk of an individual project and can produce a higher rate of return.

Includes bibliographical references (leaves 73-79). / The study was conducted with the agents in a contact centre environment in one of the leading insurance organisations in South Africa. The framework adopted was Theoretical Framework of User Satisfaction with a Web Interface which is adapted from Herzberg's Motivation-Hygiene theory.It was found that there are several factors impacting agents' job performance and customer service, including systems performance, page loading capacity, complexity and speed of information seeking tasks, system-telephonic integration, system-emails integration, system-system integration, frequent changes of service delivery processes, and difficulties of combining products with systems training. It was found that the greatest impact of these factors was on average handling time (AHT) and 'not ready' time.

Includes bibliographical references. / People with disabilities are frequently denied access to information and information technologies due to their impairments. Whereas physical impairment is a predominant, economic barriers are also a constraint for people with disabilities. The disability-poverty link hinders knowledge building resulting in a lack of information for everyday life leading to further economic poverty. Nevertheless, a paradox is observed whereby people with disabilities report a higher quality of life (QOL) than anticipated. This research explores the disability paradox by taking a hypothetico-deductive approach to investigate the influence of information behaviour on the quality of life of people with disabilities and the role that information and communication technology (ICT) contributes. Although the majority of participants had regular access to ICT no influence on quality of life was observed for technology. Likewise, information behaviour was not observed to influence quality of life. However, the type of information needed was associated with quality of life while associations were revealed between information behaviour, ICT, and type of information needed. Six primary type of information needs - Social Support; Independence; Finances and Employment; Attitude; Mobility; and Technology - were observed to exhibit a complex relationship with disability both influencing and being influenced by quality of life. An area of concern was identified in the observation of low demand for ethical information which is arguably one of the most needed areas both in ICT and for people with disabilities today. These findings are supported by literature which has failed to conclusively prove direct associations between ICT and QOL. Nonetheless, ICT access has been associated with information behaviour although verbal and media information sources are ranked highly. In this study, verbal communication was observed to be preferred for information sharing supporting findings that offline communication is a greater predictor of quality of life than online communication. Whilst respondents sought more information on technology they encounter barriers including economic limitations, inaccessibility of Internet content and technology, lack of training, fear of technology, and lack of knowledge of technology offerings. Furthermore, a negative perception of dependency on the technology was identified. This study supports prior observations that people with disabilities manifest higher quality of life than expected. While technology is not directly linked to improved quality of life it was shown to support factors that improve quality of life. For people with disabilities this includes assistive technologies and ICT for information gathering and sharing, however the very disability that the technology seeks to overcome may also be a barrier to its use.

Includes abstract. / Includes bibliographical references. / The research was undertaken in Company X, one of South Africa’s leading financial services groups. Despite a strong Business Continuity ethos inherent in the Company, an analysis of several tests over two years highlighted the fact that they experienced recurring issues within the IT Continuity sphere. The study was borne out of the need to understand why the same issues were encountered year after year, what factors contributed to these issues, and what measures were required to mitigate these issues.

Growth in online communities has generated a new labour pool. Organisations are using Web 2.0 tools to tap into this online labour pool, with one approach being 'crowdsourcing'. People from different geographical destinations can now work for organisations that are thousands of kilometres from them. Organisations face a huge task of attracting a large crowd of workers that can actively contribute answers to their business problems. Knowing what motivates users and how to keep them actively participating over a long period of time is therefore crucial. This study explores how organisational, individual, technical and social factors affect users' motivation to participate in crowdsourcing projects. A single case study using a crowdsourcing company based in South Africa was used. The crowdsourcing company uses crowdsourcing for monitoring online activities on behalf of other companies for online conversations on social platforms such as Twitter, Facebook, news articles, blog posts and listings on directory sources such as Gumtree or property listings. A qualitative study on thirteen participants was conducted through semi - structured Skype interviews. A conceptual model is presented based on the research findings. Besides re - establishing a number of factors which affect motivation to participate in crowdsourcing, the study established new emergent factors which had not been common in previous studies. The factors include authenticity of the whole crowdsourcing project, mentorship of new users by seasoned users, flexibility of technological tools in meeting users' expectations and feedback. Practical lessons drawn from the study could help crowdsourcing practitioners understand users' motivation to participate in crowdsourcing and how to ensure a conducive environment for crowd participation and hence quality output. Additionally the study could inform key considerations when implementing a crowdsourcing project in an organisation.