256 research outputs found
Entry and Return times distribution
This is a review article on the distributions of entry and return times in
dynamical systems which discusses recent results for systems of positive
entropy.Comment: To appear in "Dynamical Systems: An International Journal dedicated
to the Statistical Properties of Dynamical Systems
Limiting distribution and error terms for the number of visits to balls in non-uniformly hyperbolic dynamical systems
We show that for systems that allow a Young tower construction with
polynomially decaying correlations the return times to metric balls are in the
limit Poisson distributed. We also provide error terms which are powers of
logarithm of the radius. In order to get those uniform rates of convergence the
balls centres have to avoid a set whose size is estimated to be of similar
order. This result can be applied to non-uniformly hyperbolic maps and to any
invariant measure that satisfies a weak regularity condition. In particular it
shows that the return times to balls is Poissonian for SRB measures on
attractors.Comment: 28 page
A Comparative Analysis of Unfair Dismissal Law with Particular Reference to the Law as it Pertains to the South African Worker
This paper will begin with an investigation of the activity of the International Labour Organization (ILO) in domestic employment laws. Using this as a yardstick, a comparative analysis of the unfair dismissal laws of the United States and some foreign countries (mainly Western European) will be undertaken. Finally, the issue will be addressed in the South African context. An assessment will be made of the relative quality of the protection afforded workers in South Africa and, using conclusions reached from the comparative study, the validity of calls for a general unfair dismissal statute in the country will be considered
Triangulation in history education research, and its limitations: A view from the UK
This paper explains how different forms of triangulation have been used in recent history education research in the UK, and attempts to assess the strengths and
weaknesses of different approaches to triangulation. It also draws attention to the limitations of triangulation as a means of making claims about the validity
of research outcomes. In spite of the pronouncements of policymakers in the UK that education reforms will be ‘evidence based’, there are many examples of distortion and misrepresentation in the field of history education research. The paper gives some examples of the ways in which triangulation and mixed methods have been used in research in history education in the UK, and argues
that without an underpinning commitment to veracity and respect for evidence, sample size, research approach and range of triangulation methods cannot ensure that reasonable claims are made for the outcomes of research. The concluding section of the paper suggests ways of complementing triangulation as a means of moderating judgements and claims in history education research, and argues that it is important that history teachers have an intelligent and well-informed understanding of the potential usefulness and the limitations of research studies in history education. Although the examples of research cited are from the UK, the question of how to optimize the use of mixed methods in history education research is an important issue for researchers and academics in history education worldwide
Paper-based standard addition assays
Standard addition assays conducted on paper-based microfluidic devices are introduced as an alternative to external standards for calibrating quantitative tests. To demonstrate this technique, a colorimetric, paper-based, standard addition assay was optimized for the determination of glucose concentrations in the range of 0 to 5 mM. Comparable results were obtained from the assay via digital image colorimetry under three different lighting conditions
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