178 research outputs found

    On the upper bound of the electronic kinetic energy in terms of density functionals

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    We propose a simple density functional expression for the upper bound of the kinetic energy for electronic systems. Such a functional is valid in the limit of slowly varying density, its validity outside this regime is discussed by making a comparison with upper bounds obtained in previous work. The advantages of the functional proposed for applications to realistic systems is briefly discussed.Comment: 10 pages, no figure

    Creating a Dataset for Named Entity Recognition in the Archaeology Domain

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    In this paper, we present the development of a training dataset for Dutch Named Entity Recognition (NER) in the archaeology domain. This dataset was created as there is a dire need for semantic search within archaeology, in order to allow archaeologists to find structured information in collections of Dutch excavation reports, currently totalling around 60,000 (658 million words) and growing rapidly. To guide this search task, NER is needed. We created rigorous annotation guidelines in an iterative process, then instructed five archaeology students to annotate a number of documents. The resulting dataset contains ~31k annotations between six entity types (artefact, time period, place, context, species & material). The inter-annotator agreement is 0.95, and when we used this data for machine learning, we observed an increase in F1 score from 0.51 to 0.70 in comparison to a machine learning model trained on a dataset created in prior work. This indicates that the data is of high quality, and can confidently be used to train NER classifiersDigital ArchaeologyComputer Science

    User Requirement Solicitation for an Information Retrieval System Applied to Dutch Grey Literature in the Archaeology Domain

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    In this paper, we present the results of user requirement solicitation for a search system of grey literature in archaeology, specifically Dutch excavation reports. This search system uses Named Entity Recognition and Information Retrieval techniques to create an effective and effortless search experience. Specifically, we used Conditional Random Fields to identify entities, with an average accuracy of 56%. This is a baseline result, and we identified many possibilities for improvement. These entities were indexed in ElasticSearch and a user interface was developed on top of the index. This proof of concept was used in user requirement solicitation and evaluation with a group of end users. Feedback from this group indicated that there is a dire need for such a system, and that the first results are promising.Algorithms and the Foundations of Software technolog

    Children’s digital and non-digital play practices with Cozmo, the toy robot

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    Quasi-normal frequencies: Key analytic results

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    The study of exact quasi-normal modes [QNMs], and their associated quasi-normal frequencies [QNFs], has had a long and convoluted history - replete with many rediscoveries of previously known results. In this article we shall collect and survey a number of known analytic results, and develop several new analytic results - specifically we shall provide several new QNF results and estimates, in a form amenable for comparison with the extant literature. Apart from their intrinsic interest, these exact and approximate results serve as a backdrop and a consistency check on ongoing efforts to find general model-independent estimates for QNFs, and general model-independent bounds on transmission probabilities. Our calculations also provide yet another physics application of the Lambert W function. These ideas have relevance to fields as diverse as black hole physics, (where they are related to the damped oscillations of astrophysical black holes, to greybody factors for the Hawking radiation, and to more speculative state-counting models for the Bekenstein entropy), to quantum field theory (where they are related to Casimir energies in unbounded systems), through to condensed matter physics, (where one may literally be interested in an electron tunelling through a physical barrier).Comment: V1: 29 pages; V2: Reformatted, 31 pages. Title changed to reflect major additions and revisions. Now describes exact QNFs for the double-delta potential in terms of the Lambert W function. V3: Minor edits for clarity. Four references added. No physics changes. Still 31 page

    Co-producing across organizational boundaries: promoting asylum seeker integration in Scotland

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    This paper questions whether asylum seeker integration is promoted through inter-organisational relationships between non-profit and voluntary organisations (NPVOs) and government agencies. It focuses particularly on the role of NPVOs in service delivery (co-management) and in the delivery and planning of public services (co-governance). It presents a research study on the public services provided to asylum seekers in Glasgow and asks the following questions: What role do NPVOs play in the planning and delivery of public services? When planning and delivering public services, to what extent do NPVOs work across organisational boundaries and what kind of relationships exist? And in practice, what makes inter-organisational relationships work? This paper offers new empirical evidence and also contributes to the theoretical debate around the integration of asylum seekers

    Risking innovation:Understanding risk and public service innovation - evidence from a four nation study

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    This paper presents new evidence about the governance of risk in public service innovation. It finds that risk is currently poorly understood with public service organizations. Either it is presented as a professional issue or it is dealt with purely as an actuarial or health and safety issue. There is little understanding of risk as a core component of innovation. In response, this paper argues for a more nuanced risk governance approach that calls for transparent decision-making on risk in public service innovation in relation to its intended outcomes. Politicians and public service managers need to understand that risk is an inherent element of innovation, because it engages with uncertain outcomes. A framework needs to be evolved to balance these risks against potential benefits and which can drive forward transparent risk governance involving politicians, public service mangers, citizens and local communities and other key stakeholders. This approach also needs to accept that failure can often by an outcome of innovation. The key here is not to maintain the blame culture that has dominate the debate to date but rather to embrace failure as an opportunity to learn and to improve public services and their outcomes
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