153 research outputs found
Multiplication of Crowns
It is known that the only nite topological spaces that are H-spaces are the discrete spaces. For a nite poset which is weakly equivalent to an H-space, a generalized multiplication may be found after suitable sub-division. In this paper we construct minimal models of the
k-fold generalised multiplications of circles in the category of relational structures, including poset models. In particular, we obtain higher dimensional analogues of a cer-tain ternary multiplication of crown
An SEIRS epidemic model with stochastic transmission
For an SEIRS epidemic model with stochastic perturbations on transmission from the susceptible class to the latent and infectious classes, we prove the existence of global positive solutions. For sufficiently small values of the perturbation parameter, we prove the almost surely exponential stability of the disease-free equilibrium whenever a certain invariant R? is below unity. Here R?<R, the latter being the basic reproduction number of the underlying deterministic model. Biologically, the main result has the following significance for a disease model that has an incubation phase of the pathogen: A small stochastic perturbation on the transmission rate from susceptible to infectious via the latent phase will enhance the stability of the disease-free state if both components of the perturbation are non-trivial; otherwise the stability will not be disturbed. Simulations illustrate the main stability theorem.IS
A contribution to the foundations of the theory of Quasifibration
The concept of quasifibration was invented by Dold and Thom (DT]. May (M2] approached quasifibrations from a new angle, making use of n-equivalences. This dissertation presents a study of the notion of n-equivalences and related types of maps. The first of our two main goals is to prove a result, Theorem 5.1, which generalizes the fundamental theorem (DT; Satz 2.2] by Dold and Thom on globalization of quasifibrations. Secondly we show that by means of adjunction or clutching constructions, this theorem enables us to retrieve the famous results of James (J2; Theorem 1.2 and Theorem 1.3] in his work on suspension of spheres. The results of James appear in the thesis as Theorem 13.8. For some of the applications we need a generalized version of n-equivalence. This generalization entails replacing, in the definition of n-equivalence, the isomorphisms by isomorphisms modulo a suitable Serre class [Se] of abelian groups. For the sake of having the thesis self-contained, we include a formal discussion of localization of 1-connected spaces and Serre classes of abelian groups. This summarizes the scope of the thesis. More detail on the content of the thesis will be given after we have sketched a historical perspective on quasifibrations
A legal critique of the European Union's bilateral fisheries agreements with developing countries in West Africa with particular reference to sustainability.
The European Union currently enjoys access to the coastal fish stocks of numerous developing third countries (particularly in West Africa) in terms of bilateral fisheries agreements. These agreements are concluded under and legitimated by the international fisheries regime, which ardently promotes the sustainable use of fisheries resources and the sustainable development of fisheries. In this thesis I analyse these agreements from a (legal) sustainability perspective. Based on my research, I argue that rather than functioning as legal instruments of conservancy, these agreements operate as means to inequitably promote the respective economic and political self-interests of the parties involved. They run contrary to the sustainability tenet of international fisheries law and expose its inherent weaknesses. The need to actively promote the sustainable use of marine fisheries arises from the difficulties in ensuring their effective management, which in turn stem from their common resource nature. International law responds by obliging states to foster the long-term sustainable use of fisheries from a biological, social and economic perspective towards the broader goal of sustainable fisheries development. Coastal states, however, particularly developing countries, struggle to achieve these objectives in their own waters. The challenge is not only to ensure the rational domestic management of their fisheries but also to engender the cooperation of foreign states that access their stocks towards these ends. Fishing arrangements between the European Union (EU) and West African coastal states have on the whole not reflected such cooperation, as I illustrate in my thesis with reference to the case study of EU-Senegalese fishing relations. In response to the deficiencies of the international fisheries regime in this regard, I identify possible alternative approaches to future bilateral fisheries interactions which will likely better foster sustainable fishing
Adjunction of n-equivalences and triad connectivity
We prove a new adjunction theorem for -equivalences. This theorem enables us to produce a simple geometric version of proof of the triad connectivity theorem of Blakers and Massey. An important intermediate step is a study of the collapsing map , being a sphere
A realist assessment of the implementation of blended learning in a higher education context: the case of the Library and Information Science Department at the University of the Western Cape
Opportunities for further studies by working adults came under threat as the University of the Western Cape stopped the offering of after-hours classes in most of its Faculties. Unqualified and under-qualified librarians were directly affected by this decision. This paper outlines an assessment of the conceptualisation and implementation of an action research project initiated by the Division for Lifelong learning. Using a realist evaluation approach, the assessment focuses on the implementation of strategies aimed at showing how lifelong learning opportunities, conceptualised and provided in flexible ways, could support innovation in learning and teaching in order to enhance access and success to learning by working people in the context of the Library and Information Science Department
Indigenous female entrepreneurship : analytical study on access to finance for women entrepreneurs in South Africa
Research on female entrepreneurship is imperative to create a knowledge base of womenâs experiences with regards to being financially excluded in South Africa. There is a realisation, however, that, while race has historically been the primary driver of economic disparities in South Africa, other forms of discrimination also prevent certain groups from accessing economic freedom and opportunities. Women, who represent 52% of the South African population, still suffer from historical and cultural prejudice in accessing opportunities, for a number of reasons that are outlined in this study. While access to financial services continues to be largely racially defined in South Africa, the gender gap between men and women does exist, and is likely to grow if special efforts are not undertaken to address the underlying issues now. Black women are the largest single self-employed segment of the population; a fact that is not reflected in the current industry targets for business activity. This paper examines the extent to which financial service providers in the country were sufficiently aware of the challenges facing women entrepreneurs in South Africa
A realist assessment of the implementation of blended learning in a South African higher education context
Opportunities for further studies by working adults came under threat as the University of the Western Cape stopped the offering of after-hours classes in most of its Faculties. Unqualified and under-qualified librarians were directly affected by this decision. This article outlines an assessment of the conceptualisation and implementation of an action research project initiated by the Division for Lifelong learning. Using a realist evaluation approach, the assessment focuses on the implementation of strategies aimed at showing how lifelong learning opportunities, conceptualised and provided in flexible ways, could support innovation in learning and teaching in order to enhance access and success to learning by working people in the context of the Library and Information Science Department.DHE
Keeping the doors of learning open for adult student-workers within higher education
The Freedom Charter of the African National Congress (ANC), the triumphant South African liberation movement, proclaims that âthe doors of learning shall be openâ for all. Twenty years since coming to power, the doors of the universities are struggling to stay open for adult student-workers. An action research project into implementation of âflexible provisionâ at one historically black university is described in response to these realities. Rich experiences from lives of working librarian student-workers illustrate the complex issues that confront individuals, workplaces and institutions in implementing innovative pedagogies within a university
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