2,070 research outputs found

    Results from the LSND Neutrino Oscillation Search

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    The Liquid Scintillator Neutrino Detector (LSND) at the Los Alamos Meson Physics Facility sets bounds on neutrino oscillations in the appearance channel nu_mu_bar --> nu_e_bar by searching for the signature of the reaction nu_e_bar p --> e^+ n: an e+^+ followed by a 2.2MeV gamma ray from neutron capture. Five e^{+/-} -- gamma coincidences are observed in time with the LAMPF beam, with an estimated background of 6.2 events. The 90\% confidence limits obtained are: Delta (m^2) < 0.07eV^2 for sin^2 (2theta) = 1, and sin^2(2theta) < 6 10^{-3} for Delta (m^2) > 20 eV^2.Comment: 10 pages, uses REVTeX and epsf macro

    Numerical Computations with H(div)-Finite Elements for the Brinkman Problem

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    The H(div)-conforming approach for the Brinkman equation is studied numerically, verifying the theoretical a priori and a posteriori analysis in previous work of the authors. Furthermore, the results are extended to cover a non-constant permeability. A hybridization technique for the problem is presented, complete with a convergence analysis and numerical verification. Finally, the numerical convergence studies are complemented with numerical examples of applications to domain decomposition and adaptive mesh refinement.Comment: Minor clarifications, added references. Reordering of some figures. To appear in Computational Geosciences, final article available at http://www.springerlink.co

    Assessing the utility of the national student financial aid scheme towards skills development: A case of a rural university in South Africa

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    The National Student Financial Aid Scheme (NSFAS) was introduced in 1999 in South Africa to provide financial support for disadvantaged students through the provision of both loans and bursaries. This article reflects on the effects of the scheme on skills development within two faculties at the University of Limpopo. The research was undertaken in 2021 employing an exploratory qualitative methodology. A total of eighteen participants were purposively selected from two of the four faculties of the University of Limpopo. A semi-structured interview guide was utilised to elicit narrative data from all participating beneficiaries of the NSFAS. The narrative data were analysed using a thematic coding design and interpretations of the findings were subsequently made. The interpretation of the analysis focused on the effect of the NSFAS support on students’ skills development. The findings suggest that NSFAS funding contributed to the development of soft skills of beneficiaries which included financial security; spending prioritisation and collaborative budgeting; time-management skills; self-esteem and skills development opportunities. Whilst the findings are localised, they do suggest that further research could be undertaken into the potentials of NSFAS to boost students’ soft skills development during their time within a higher education institution

    Weakly Consistent Regularisation Methods for Ill-Posed Problems

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    This Chapter takes its origin in the lecture notes for a 9 h course at the Institut Henri Poincaré in September 2016. The course was divided in three parts. In the first part, which is not included herein, the aim was to first recall some basic aspects of stabilised finite element methods for convection-diffusion problems. We focus entirely on the second and third parts which were dedicated to ill-posed problems and their approximation using stabilised finite element methods. First we introduce the concept of conditional stability. Then we consider the elliptic Cauchy-problem and a data assimilation problem in a unified setting and show how stabilised finite element methods may be used to derive error estimates that are consistent with the stability properties of the problem and the approximation properties of the finite element space. Finally, we extend the result to a data assimilation problem subject to the heat equation

    Managing at the Speed of Light: Improving Mission-Support Performance

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    The House and Senate Energy and Water Development Appropriations Subcommittees requested this study to help DOE's three major mission-support organizations improve their operations to better meet the current and future needs of the department. The passage of the Recovery Act only increased the importance of having DOE's mission-support offices working in the most effective, efficient, and timely manner as possible. While following rules and regulations is essential, the foremost task of the mission-support offices is to support the department's mission, i.e., the programs that DOE is implementing, whether in Washington D.C. or in the field. As a result, the Panel offered specific recommendations to strengthen the mission-focus and improve the management of each of the following support functions based on five "management mandates":- Strategic Vision- Leadership- Mission and Customer Service Orientation- Tactical Implementation- Agility/AdaptabilityKey FindingsThe Panel made several recommendations in each of the functional areas examined and some overarching recommendations for the corporate management of the mission-support offices that they believed would result in significant improvements to DOE's mission-support operations. The Panel believed that adopting these recommendations will not only make DOE a better functioning organization, but that most of them are essential if DOE is to put its very large allocation of Recovery Act funding to its intended uses as quickly as possible

    Deconstructive discourse analysis: extending the methodological conversation

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    Discourse analysis is increasingly becoming a methodology of preference amongst qualitative researchers. There is a danger, however, of it being viewed as a bounded and uncontested domain of research practice. As discourse analysis is inextricably linked with theoretical issues, it is a dynamic practice that is constantly in a process of revision. In this paper I reflect on some of the conceptualisations undergirding the notion of discourse – conceptualisations that have important implications in terms of how the practice of discourse analysis proceeds. I highlight some of the dualisms that may plague discourse analysis, and offer some solutions to these. Finally, I outline the deconstructive discourse analysis that I utilised in my doctoral work. The purpose of the latter is not to provide a recipe of methodology, but to illustrate how elements of various theorists’ work (in this case Foucault, Derrida and Parker) may be profitably drawn together to perform specific discourse analytic work.Rhodes Universit

    Children’s experiences of domestic violence and abuse: siblings’ accounts of relational coping

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    This article explores how young people see their relationships, particularly their sibling relationships, in families affected by domestic violence, and how relationality emerges in their accounts as a resource to build an agentic sense of self. The ‘voice’ of children is largely absent from domestic violence literature, which typically portrays them as passive, damaged and relationally incompetent. Children’s own understandings of their relational worlds are often overlooked, and consequently existing models of children’s social interactions give inadequate accounts of their meaning-making-in-context. Drawn from a larger study of children’s experiences of domestic violence and abuse, this paper uses two case studies of sibling relationships to explore young people’s use of relational resources, for coping with violence in the home. The paper explores how relationality and coping intertwine in young people’s accounts, and disrupts the taken for granted assumption that children’s ‘premature caring’ or ‘parentification’ is (only) pathological in children’s responses to domestic violence. This has implications for understanding young people’s experiences in the present, and supporting their capacity for relationship building in the future

    A Pressure-Robust Discretization of Oseen's Equation Using Stabilization in the Vorticity Equation

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    Discretization of Navier--Stokes equations using pressure-robust finite element methods is considered for the high Reynolds number regime. To counter oscillations due to dominating convection we add a stabilization based on a bulk term in the form of a residual-based least squares stabilization of the vorticity equation supplemented by a penalty term on (certain components of) the gradient jump over the elements faces. Since the stabilization is based on the vorticity equation, it is independent of the pressure gradients, which makes it pressure-robust. Thus, we prove pressure-independent error estimates in the linearized case, known as Oseen's problem. In fact, we prove an O(hk+12)O(h^{k+\frac12}) error estimate in the L2L^2-norm that is known to be the best that can be expected for this type of problem. Numerical examples are provided that, in addition to confirming the theoretical results, show that the present method compares favorably to the classical residual-based streamline upwind Petrov--Galerkin stabilization

    A Superstabilizing log(n)\log(n)-Approximation Algorithm for Dynamic Steiner Trees

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    In this paper we design and prove correct a fully dynamic distributed algorithm for maintaining an approximate Steiner tree that connects via a minimum-weight spanning tree a subset of nodes of a network (referred as Steiner members or Steiner group) . Steiner trees are good candidates to efficiently implement communication primitives such as publish/subscribe or multicast, essential building blocks for the new emergent networks (e.g. P2P, sensor or adhoc networks). The cost of the solution returned by our algorithm is at most logS\log |S| times the cost of an optimal solution, where SS is the group of members. Our algorithm improves over existing solutions in several ways. First, it tolerates the dynamism of both the group members and the network. Next, our algorithm is self-stabilizing, that is, it copes with nodes memory corruption. Last but not least, our algorithm is \emph{superstabilizing}. That is, while converging to a correct configuration (i.e., a Steiner tree) after a modification of the network, it keeps offering the Steiner tree service during the stabilization time to all members that have not been affected by this modification
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