Today's hardware is becoming more and more parallel. While embarrassingly parallel codes, such as high-performance computing ones, can readily take advantage of this increased number of cores, most other types of code cannot easily scale using traditional data and/or task parallelism and cores are therefore left idling resulting in lost opportunities to improve performance. The opportunistic computing paradigm, on which this thesis rests, is the idea that computations should dynamically adapt to and exploit the opportunities that arise due to idling resources to enhance their performance or quality. In this thesis, I propose to utilize algorithmic properties to develop programming models that leverage this idea thereby providing models that increase and improve the parallelism that can be exploited. I exploit three distinct algorithmic properties: i) algorithmic diversity, ii) the semantic content of data-structures, and iii) the variable nature of results in certain applications. This thesis presents three main contributions: i) the N-way model which leverages algorithmic diversity to speed up hitherto sequential code, ii) an extension to the N-way model which opportunistically improves the quality of computations and iii) a framework allowing the programmer to specify the semantics of data-structures to improve the performance of optimistic parallelism.

Theorists and management in the South African non-profit sector agree that strong stakeholder relationships are essential in negotiating the challenges faced by the South African non-profit sector. Despite the acknowledgement from the non-profit sector that strong relationships are key to achieving organisational goals, there is an apparent lack of knowledge and strategic thinking amongst them pertaining to the concept of stakeholder relationship management. Against this background the purpose of this study was therefore to develop a metamodern model for stakeholder relationship management, aimed specifically at the South African non-profit sector, that could be implemented by NPO management in a practical manner. The blurring lines between the opposing views of modernism versus postmodernism motivated the choice of metamodernism as a relevant worldview for this study. Metamodernism does not imply a balance between these poles, but rather a constant swinging of the pendulum during which metamodernism negotiates between modernism and postmodernism. It is the construction of a workable, interrelated worldview, recognising the intimate relationship between modernism and postmodernism. It was therefore concluded that a metamodern worldview in which both modernism and postmodernism feature, would not only make it possible for nonprofit organisation managers to understand and join the discussion on stakeholder relationship management, but also to implement the proposed metamodern stakeholder relationship management model. The resultant metamodern stakeholder relationship management model for non-profit organisations is framed by so-called modernistic communication and stakeholder relationship management theories, but it was done in line with the metamodern worldview of the study, allowing for initiative and innovation. The flexible, organic and cyclic nature of the proposed model echoes this worldview. A qualitative, exploratory and interpretative research design was implemented to test a conceptual framework and face-to-face semi-structured interviews were conducted with senior management in the non-profit sector. The design of the framework and subsequent model was guided by a number of assumptions and propositions arising from a thorough literature review, all of which were supported and confirmed by the research results. The most significant contribution of the study is the application of a metamodern worldview emanating from a reluctance to choose between a modern or postmodern stance when discussing communication science and stakeholder relationship management practices. It is therefore foreseen that it would offer the field of communication science new and creative means of combining modernism and postmodernism approaches when studying communication phenomena. It will also expand the responsibility for communication and stakeholder relationship management beyond that of the communication specialists to senior management in the non-profit sector. / Communication Science / D. Litt. et Phil. (Communication)