847,365 research outputs found

    A Note on the Concept of Excess Burden

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    It is argued that there has been a shift in the meaning of "excess burden" from Pigou to modern economics, related to what is used as a reference point when the effect of a tax is discussed. Is it the situation before the tax was introduced or what would have happened if a lump sum tax had been used instead? This distinction is important for tax policy, since the latter reference point leads to a larger, sometimes much larger, numerical value for the excess burden. However, the distinction is not often clearly made and this has led to risks for misguided political decisions on taxes. It is further argued that when excess burden and efficiency losses are discussed, economists have neglected to discuss the meaning of “can”, or “possible”, when the Pareto principle is formulated. Is it reasonable to say that welfare "can" be improved by a lump sum tax instead of a "distortionary" tax if, as most economists seem to believe, such a tax is not a realistic alternative? Since conceptual clearness about the excess burden of taxes is important, some suggestions for improving the situation are also presented.Excess burden; Pigou, distortion; lump-sum tax

    Introduction: Why Should We Study Migration Policies at the Interface between Empirical Research and Normative Analysis?

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    The text introduces the concept behind the Proceedings of the 2018 ZiF Workshop “Studying Migration Policies at the Interface between Empirical Research and Normative Analysis”. It explains why there is a need to study migration policies across disciplines, includes a short note on the current literature, and provides a look back at the workshop. DOI:10.17879/1519962468

    The enigma of Vitruvian resonating vases and the relevance of the concept for today

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    The clarity of sound within Greek or Roman theatres (without any form of enhancement) will be impressive to any visitor. The seats arranged in curved rows around the circular orchestra form large horizontal reflecting surfaces. The paths of sound waves travel from the source (the actor or singer) to each of the listeners in a direct path (i.e. without obstruction or reflection). Vitruvius, however, claimed further enhancements could be made. In theatres, also, are copper vases and these are placed in chambers under the rows of seats in accordance with mathematical reckoning. The Greeks call them Echeia. The differences of the sounds which arise are combined into musical symphonies... … it becomes fuller, and reaches the audience with a richer and sweeter note. Vitruvius, on Architecture, Book I, – on training of architects, Loeb This paper explores the notion of intent and purpose behind the Vitruvian concept and also addresses an arguably more complex issue, that of a potential fusion between archaeology, science and art.Peer reviewe

    FPGA-based operational concept and payload data processing for the Flying Laptop satellite

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    Flying Laptop is the first small satellite developed by the Institute of Space Systems at the Universität Stuttgart. It is a test bed for an on-board computer with a reconfigurable, redundant and self-controlling high computational ability based on the field pro- grammable gate arrays (FPGAs). This Technical Note presents the operational concept and the on-board payload data processing of the satellite. The designed operational concept of Flying Laptop enables the achievement of mission goals such as technical demonstration, scientific Earth observation, and the payload data processing methods. All these capabilities expand its scientific usage and enable new possibilities for real-time applications. Its hierarchical architecture of the operational modes of subsys- tems and modules are developed in a state-machine diagram and tested by means of MathWorks Simulink-/Stateflow Toolbox. Furthermore, the concept of the on-board payload data processing and its implementation and possible applications are described

    Spatiotemporal complexity of the universe at subhorizon scales

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    This is a short note on the spatiotemporal complexity of the dynamical state(s) of the universe at subhorizon scales (up to 300 Mpc). There are reasons, based mainly on infrared radiative divergences, to believe that one can encounter a flicker noise in the time domain, while in the space domain, the scaling laws are reflected in the (multi)fractal distribution of galaxies and their clusters. There exist recent suggestions on a unifying treatment of these two aspects within the concept of spatiotemporal complexity of dynamical systems driven out of equilibrium. Spatiotemporal complexity of the subhorizon dynamical state(s) of the universe is a conceptually nice idea and may lead to progress in our understanding of the material structures at large scalesComment: references update

    The squeezed generalized amplitude damping channel

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    Squeezing of a thermal bath introduces new features absent in an open quantum system interacting with an uncorrelated (zero squeezing) thermal bath. The resulting dynamics, governed by a Lindblad-type evolution, extends the concept of a generalized amplitude damping channel, which corresponds to a dissipative interaction with a purely thermal bath. Here we present the Kraus representation of this map, which we call the squeezed generalized amplitude damping channel. As an application of this channel to quantum information, we study the classical capacity of this channel.Comment: Accepted for publication in Physical Review A; note on methods of generating bath squeezing added in Section II A; 12 pages, 7 figure

    Developing a manually annotated clinical document corpus to identify phenotypic information for inflammatory bowel disease

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    <p>Abstract</p> <p>Background</p> <p>Natural Language Processing (NLP) systems can be used for specific Information Extraction (IE) tasks such as extracting phenotypic data from the electronic medical record (EMR). These data are useful for translational research and are often found only in free text clinical notes. A key required step for IE is the manual annotation of clinical corpora and the creation of a reference standard for (1) training and validation tasks and (2) to focus and clarify NLP system requirements. These tasks are time consuming, expensive, and require considerable effort on the part of human reviewers.</p> <p>Methods</p> <p>Using a set of clinical documents from the VA EMR for a particular use case of interest we identify specific challenges and present several opportunities for annotation tasks. We demonstrate specific methods using an open source annotation tool, a customized annotation schema, and a corpus of clinical documents for patients known to have a diagnosis of Inflammatory Bowel Disease (IBD). We report clinician annotator agreement at the document, concept, and concept attribute level. We estimate concept yield in terms of annotated concepts within specific note sections and document types.</p> <p>Results</p> <p>Annotator agreement at the document level for documents that contained concepts of interest for IBD using estimated Kappa statistic (95% CI) was very high at 0.87 (0.82, 0.93). At the concept level, F-measure ranged from 0.61 to 0.83. However, agreement varied greatly at the specific concept attribute level. For this particular use case (IBD), clinical documents producing the highest concept yield per document included GI clinic notes and primary care notes. Within the various types of notes, the highest concept yield was in sections representing patient assessment and history of presenting illness. Ancillary service documents and family history and plan note sections produced the lowest concept yield.</p> <p>Conclusion</p> <p>Challenges include defining and building appropriate annotation schemas, adequately training clinician annotators, and determining the appropriate level of information to be annotated. Opportunities include narrowing the focus of information extraction to use case specific note types and sections, especially in cases where NLP systems will be used to extract information from large repositories of electronic clinical note documents.</p

    On the geometry of the consumer's surplus line integral

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    Consumer's surplus can be seen as a correct measure of the change in welfare under special conditions on the preferences of the consumer. The note addresses the question whether the intuitive appeal of the consumer''s surplus concept in the one-price change case extends into cases where several prices of inter-related goods change. An intuitively justified attribution of the change in welfare is conjectured. Sufficient conditions for this attribution to be exactly consistent with the geometry of the consumer''s surplus line integral are discussed.
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