451 research outputs found

    Development needs and perceptions of senior managers in Namibian state owned enterprises

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    Thesis (M.M. (Business and Executive Coaching))--University of the Witwatersrand, Faculty of Commerce, Law and Management, Graduate School of Business Administration, 2012.According to the Namibian Minister of Finance, Namibian state owned enterprises (SOEs) generally underperform: the majority are unable to pay dividends to their shareholders. In the local press-reported public perception, this is due to an apparent lack of competency at, mainly, senior management level. In the organisational development world, it is assumed that senior manager coaching, as one of several potential organisational development process initiatives, would lead to greater senior manager competence, and thus improved organisational efficiency. However, in Namibia, no known research exists on whether this is indeed the case, or on what senior manager development needs actually are. From this research gap derives the research question: What are the development needs and perceptions of senior managers in Namibian state owned enterprises? Situated within an ecosystemic paradigm and Maslow’s humanist hierarchy of needs psychological theory, this study adopts a holistic, interpretive, and empirical approach in one purposively selected SOE to explore this question. Findings suggest that senior managers’ development needs are clustered mainly in Maslow’s “deficiency” category of needs. In particular, managers experience anxiety around competency issues, and a general lack of recognition and appreciation. In contrast, however, the study found a strong sense of affiliation, even loyalty, towards the SOE studied. The frequency with which organisational deficiencies were also mentioned nevertheless suggests that it would be insufficient to address senior manager development needs in isolation from broader organisational development process interventions. The report concludes with recommendations inter alia, for further research particularly around the issues of individual competence, recognition, and affiliation within an organisational context

    Elective Recital: Freshbones

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    New coins from old, smoothly

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    Given a (known) function f:[0,1](0,1)f:[0,1] \to (0,1), we consider the problem of simulating a coin with probability of heads f(p)f(p) by tossing a coin with unknown heads probability pp, as well as a fair coin, NN times each, where NN may be random. The work of Keane and O'Brien (1994) implies that such a simulation scheme with the probability p(N<)\P_p(N<\infty) equal to 1 exists iff ff is continuous. Nacu and Peres (2005) proved that ff is real analytic in an open set S(0,1)S \subset (0,1) iff such a simulation scheme exists with the probability p(N>n)\P_p(N>n) decaying exponentially in nn for every pSp \in S. We prove that for α>0\alpha>0 non-integer, ff is in the space Cα[0,1]C^\alpha [0,1] if and only if a simulation scheme as above exists with p(N>n)C(Δn(p))α\P_p(N>n) \le C (\Delta_n(p))^\alpha, where \Delta_n(x)\eqbd \max \{\sqrt{x(1-x)/n},1/n \}. The key to the proof is a new result in approximation theory: Let \B_n be the cone of univariate polynomials with nonnegative Bernstein coefficients of degree nn. We show that a function f:[0,1](0,1)f:[0,1] \to (0,1) is in Cα[0,1]C^\alpha [0,1] if and only if ff has a series representation n=1Fn\sum_{n=1}^\infty F_n with F_n \in \B_n and k>nFk(x)C(Δn(x))α\sum_{k>n} F_k(x) \le C(\Delta_n(x))^\alpha for all x[0,1] x \in [0,1] and n1n \ge 1. We also provide a counterexample to a theorem stated without proof by Lorentz (1963), who claimed that if some \phi_n \in \B_n satisfy f(x)ϕn(x)C(Δn(x))α|f(x)-\phi_n(x)| \le C (\Delta_n(x))^\alpha for all x[0,1] x \in [0,1] and n1n \ge 1, then fCα[0,1]f \in C^\alpha [0,1].Comment: 29 pages; final version; to appear in Constructive Approximatio

    The Search as Learning Spaceship: Toward a Comprehensive Model of Psychological and Technological Facets of Search as Learning

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    Using a Web search engine is one of today’s most frequent activities. Exploratory search activities which are carried out in order to gain knowledge are conceptualized and denoted as Search as Learning (SAL). In this paper, we introduce a novel framework model which incorporates the perspective of both psychology and computer science to describe the search as learning process by reviewing recent literature. The main entities of the model are the learner who is surrounded by a specific learning context, the interface that mediates between the learner and the information environment, the information retrieval (IR) backend which manages the processes between the interface and the set of Web resources, that is, the collective Web knowledge represented in resources of different modalities. At first, we provide an overview of the current state of the art with regard to the five main entities of our model, before we outline areas of future research to improve our understanding of search as learning processes. Copyright © 2022 von Hoyer, Hoppe, Kammerer, Otto, Pardi, Rokicki, Yu, Dietze, Ewerth and Holtz

    Efficient cosmological parameter sampling using sparse grids

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    We present a novel method to significantly speed up cosmological parameter sampling. The method relies on constructing an interpolation of the CMB-log-likelihood based on sparse grids, which is used as a shortcut for the likelihood-evaluation. We obtain excellent results over a large region in parameter space, comprising about 25 log-likelihoods around the peak, and we reproduce the one-dimensional projections of the likelihood almost perfectly. In speed and accuracy, our technique is competitive to existing approaches to accelerate parameter estimation based on polynomial interpolation or neural networks, while having some advantages over them. In our method, there is no danger of creating unphysical wiggles as it can be the case for polynomial fits of a high degree. Furthermore, we do not require a long training time as for neural networks, but the construction of the interpolation is determined by the time it takes to evaluate the likelihood at the sampling points, which can be parallelised to an arbitrary degree. Our approach is completely general, and it can adaptively exploit the properties of the underlying function. We can thus apply it to any problem where an accurate interpolation of a function is needed.Comment: Submitted to MNRAS, 13 pages, 13 figure

    Cancellous bone and theropod dinosaur locomotion. Part I—an examination of cancellous bone architecture in the hindlimb bones of theropods

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    This paper is the first of a three-part series that investigates the architecture of cancellous (‘spongy’) bone in the main hindlimb bones of theropod dinosaurs, and uses cancellous bone architectural patterns to infer locomotor biomechanics in extinct non-avian species. Cancellous bone is widely known to be highly sensitive to its mechanical environment, and has previously been used to infer locomotor biomechanics in extinct tetrapod vertebrates, especially primates. Despite great promise, cancellous bone architecture has remained little utilized for investigating locomotion in many other extinct vertebrate groups, such as dinosaurs. Documentation and quantification of architectural patterns across a whole bone, and across multiple bones, can provide much information on cancellous bone architectural patterns and variation across species. Additionally, this also lends itself to analysis of the musculoskeletal biomechanical factors involved in a direct, mechanistic fashion. On this premise, computed tomographic and image analysis techniques were used to describe and analyse the three-dimensional architecture of cancellous bone in the main hindlimb bones of theropod dinosaurs for the first time. A comprehensive survey across many extant and extinct species is produced, identifying several patterns of similarity and contrast between groups. For instance, more stemward non-avian theropods (e.g. ceratosaurs and tyrannosaurids) exhibit cancellous bone architectures more comparable to that present in humans, whereas species more closely related to birds (e.g. paravians) exhibit architectural patterns bearing greater similarity to those of extant birds. Many of the observed patterns may be linked to particular aspects of locomotor biomechanics, such as the degree of hip or knee flexion during stance and gait. A further important observation is the abundance of markedly oblique trabeculae in the diaphyses of the femur and tibia of birds, which in large species produces spiralling patterns along the endosteal surface. Not only do these observations provide new insight into theropod anatomy and behaviour, they also provide the foundation for mechanistic testing of locomotor hypotheses via musculoskeletal biomechanical modelling

    New Information on the Cranial Anatomy of Acrocanthosaurus atokensis and Its Implications for the Phylogeny of Allosauroidea (Dinosauria: Theropoda)

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    Allosauroidea has a contentious taxonomic and systematic history. Within this group of theropod dinosaurs, considerable debate has surrounded the phylogenetic position of the large-bodied allosauroid Acrocanthosaurus atokensis from the Lower Cretaceous Antlers Formation of North America. Several prior analyses recover Acrocanthosaurus atokensis as sister taxon to the smaller-bodied Allosaurus fragilis known from North America and Europe, and others nest Acrocanthosaurus atokensis within Carcharodontosauridae, a large-bodied group of allosauroids that attained a cosmopolitan distribution during the Early Cretaceous.Re-evaluation of a well-preserved skull of Acrocanthosaurus atokensis (NCSM 14345) provides new information regarding the palatal complex and inner surfaces of the skull and mandible. Previously inaccessible internal views and articular surfaces of nearly every element of the skull are described. Twenty-four new morphological characters are identified as variable in Allosauroidea, combined with 153 previously published characters, and evaluated for eighteen terminal taxa. Systematic analysis of this dataset recovers a single most parsimonious topology placing Acrocanthosaurus atokensis as a member of Allosauroidea, in agreement with several recent analyses that nest the taxon well within Carcharodontosauridae.A revised diagnosis of Acrocanthosaurus atokensis finds that the species is distinguished by four primary characters, including: presence of a knob on the lateral surangular shelf; enlarged posterior surangular foramen; supraoccipital protruding as a double-boss posterior to the nuchal crest; and pneumatic recess within the medial surface of the quadrate. Furthermore, the recovered phylogeny more closely agrees with the stratigraphic record than hypotheses that place Acrocanthosaurus atokensis as more closely related to Allosaurus fragilis. Fitch optimization of body size is also more consistent with the placement of Acrocanthosaurus atokensis within a clade of larger carcharodontosaurid taxa than with smaller-bodied taxa near the base of Allosauroidea. This placement of Acrocanthosaurus atokensis supports previous hypotheses of a global carcharodontosaurid radiation during the Early Cretaceous
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