410,407 research outputs found

    Synthesis of aquaculture policy and development approaches in Africa

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    The WorldFish Center was tasked to undertake a study to access, collate and develop background materials to produce an internationally linked and Africa-wide perspective on sectorally relevant policy issues. The specific objective of the study was to assess and define conditions and impact pathways, in Africa or elsewhere, where markets, policies, resources and technologies have combined to promote steady and sustainable growth of aquaculture, and where have been clear direct impacts on food supply, income, employment and consumption opportunities, as well as increase in supply that has led to stabilised prices. The study was also aimed at providing guidelines for scaling up the implementation of the synthesis study via Afri-FishNet (CAADP Fish Expert Pools) at the national and regional levels

    A Morphology of Theories of Emergence

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    “Emergence” – the notion of novel, unpredictable and irreducible properties developing out of complex organisational entities – is itself a complex, multi-dimensional concept. To date there is no single, generally agreed upon “theory of emergence”, but instead a number of different approaches and perspectives. Neither is there a common conceptual or meta-theoretical framework by which to systematically identify, exemplify and compare different “theories”. Building upon earlier work done by sociologist Kenneth Bailey, this article presents a method for creating such a framework, and outlines the conditions for a collaborative effort in order to carry out such a task. A brief historical and theoretical background is given both to the concept of “emergence” and to the non-quantified modelling method General Morphological Analysis (GMA)

    Contradictions in adult education structures and policies in Austria: their interrelation with the professional development of educators

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    This article analyses the structural influences on the professional development of adult educators and their relation to education policy using Austria as a fairly average example of the diversity in European adult education. The position of adult education is first analysed in the course of the development of a lifelong learning strategy, showing a set of basic contradictions that are institutionally embedded in educational practices and policies. The consequences of these constellations for professional development in adult education are then examined, and a policy analysis undertaken based on institutional theory and using literature, documents and secondary data. This analysis shows that the contradictions in the institutional structures and policies inhibit both the development of a lifelong learning strategy as well as the professional development of adult educators. The competence development and quality assurance approaches adopted in Europe contribute only very modestly to the development of adult education in Austria. (DIPF/orig.

    Learning to Rank Academic Experts in the DBLP Dataset

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    Expert finding is an information retrieval task that is concerned with the search for the most knowledgeable people with respect to a specific topic, and the search is based on documents that describe people's activities. The task involves taking a user query as input and returning a list of people who are sorted by their level of expertise with respect to the user query. Despite recent interest in the area, the current state-of-the-art techniques lack in principled approaches for optimally combining different sources of evidence. This article proposes two frameworks for combining multiple estimators of expertise. These estimators are derived from textual contents, from graph-structure of the citation patterns for the community of experts, and from profile information about the experts. More specifically, this article explores the use of supervised learning to rank methods, as well as rank aggregation approaches, for combing all of the estimators of expertise. Several supervised learning algorithms, which are representative of the pointwise, pairwise and listwise approaches, were tested, and various state-of-the-art data fusion techniques were also explored for the rank aggregation framework. Experiments that were performed on a dataset of academic publications from the Computer Science domain attest the adequacy of the proposed approaches.Comment: Expert Systems, 2013. arXiv admin note: text overlap with arXiv:1302.041

    Crossover from Spin-Density-Wave to Neel-like Ground state

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    The characterization and evolution of a Spin Density Wave into the Quantum Neel ground state is considered in the context of a weak coupling theory of the half-filled Hubbard model. Magnetic properties obtained from this weak coupling approach in one dimension compare favorably with exact results from Bethe ansatz (BA). A study of the evolution of several length scales from weak to strong coupling is also presented.Comment: [email protected] Pages: 18 (REVTEX 3.0). 6 postscript figures available upon reques

    Full Semantics Preservation in Model Transformation – A Comparison of Proof Techniques

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    Model transformation is a prime technique in modern, model-driven software design. One of the most challenging issues is to show that the semantics of the models is not affected by the transformation. So far, there is hardly any research into this issue, in particular in those cases where the source and target languages are different.\ud \ud In this paper, we are using two different state-of-the-art proof techniques (explicit bisimulation construction versus borrowed contexts) to show bisimilarity preservation of a given model transformation between two simple (self-defined) languages, both of which are equipped with a graph transformation-based operational semantics. The contrast between these proof techniques is interesting because they are based on different model transformation strategies: triple graph grammars versus in situ transformation. We proceed to compare the proofs and discuss scalability to a more realistic setting.\u

    The Dimensions of Field Theory : From Particles to Strings

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    This is an editorial summary of the contents of a Book comprising a set of Articles by acknowledged experts dealing with the impact of Field Theory on major areas of physics (from elementary particles through condensed matter to strings), arranged subjectwise under six broad heads. The Book which emphasizes the conceptual, logical and formal aspects of the state of the art in these respective fields, carries a Foreword by Freeman Dyson, and is to be published by the Indian National Science Academy on the occasion of the International Mathematical Year 2000. The authors and full titles of all the Articles (33) are listed sequentially (in the order of their first appearance in the narration) under the bibliography at the end of this Summary, while a few of the individual articles to appear in the Book are already available on the LANL internet.Comment: LaTex file, 24 page
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