244,654 research outputs found

    Obstacle-aware Adaptive Informative Path Planning for UAV-based Target Search

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    Target search with unmanned aerial vehicles (UAVs) is relevant problem to many scenarios, e.g., search and rescue (SaR). However, a key challenge is planning paths for maximal search efficiency given flight time constraints. To address this, we propose the Obstacle-aware Adaptive Informative Path Planning (OA-IPP) algorithm for target search in cluttered environments using UAVs. Our approach leverages a layered planning strategy using a Gaussian Process (GP)-based model of target occupancy to generate informative paths in continuous 3D space. Within this framework, we introduce an adaptive replanning scheme which allows us to trade off between information gain, field coverage, sensor performance, and collision avoidance for efficient target detection. Extensive simulations show that our OA-IPP method performs better than state-of-the-art planners, and we demonstrate its application in a realistic urban SaR scenario.Comment: Paper accepted for International Conference on Robotics and Automation (ICRA-2019) to be held at Montreal, Canad

    [Review of] Carolyn Martindale. The White Press and Black America

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    The White Press and Black America chronicles the many deficiencies of press coverage of black America. Martindale, an assistant professor of journalism at Youngstown State University, has worked as a newspaper reporter and section editor and has published articles in several scholarly journals. She is to be commended for her compelling and informative book

    Substantiating a political public sphere in the Scottish press : a comparative analysis

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    This article uses content analysis to characterize the performance of the media in a national public sphere, by setting apart those qualities that typify internal press coverage of a political event. The article looks at the coverage of the 1999 devolved Scottish election from the day before the election until the day after. It uses a word count to measure the election material in Scottish newspapers the Herald, the Press and Journal and the Scotsman, and United Kingdom newspapers the Guardian, the Independent and The Times, and categorizes that material according to discourse type, day and page selection. The article finds a number of qualities that typify the Scottish sample in particular, and might be broadly indicative of a political public sphere in action. Firstly, and not unexpectedly, it finds that the Scottish newspapers carry significantly more election coverage. Just as tellingly, though, the article finds that the Scottish papers offer a greater proportion of advice and background information, in the form of opinion columns and feature articles. It also finds that the Scottish papers place a greater concentration of both informative and evaluative material in the period before the vote, consistent with their making a contribution to informed political action. Lastly, the article finds that the Scottish sample situates coverage nearer the front of the paper and places a greater proportion on recto pages. The article therefore argues that the Scottish papers display features that distinguish them from the UK papers, and are broadly consistent with their forming part of a deliberative public sphere, and suggests that these qualities might be explored as a means of judging future media performance

    Catastrophic Health Expenditure and Household Well-Being

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    According to the catastrophic health expenditure methodology a house-hold is in catastrophe if its health out-of-pocket budget share exceeds a critical threshold. We develop a conceptual framework for addressing three questions in relation to this methodology, namely: 1. Can a budget share be informative about the sign of a change in welfare? 2. Is there a positive association between a households poverty shortfall and its health out-of-pocket budget share? 3. Does an increase in coverage of a health insurance scheme always result in a reduction of the prevalence of catastrophic ex-penditures?

    Towards Universal Semantic Tagging

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    The paper proposes the task of universal semantic tagging---tagging word tokens with language-neutral, semantically informative tags. We argue that the task, with its independent nature, contributes to better semantic analysis for wide-coverage multilingual text. We present the initial version of the semantic tagset and show that (a) the tags provide semantically fine-grained information, and (b) they are suitable for cross-lingual semantic parsing. An application of the semantic tagging in the Parallel Meaning Bank supports both of these points as the tags contribute to formal lexical semantics and their cross-lingual projection. As a part of the application, we annotate a small corpus with the semantic tags and present new baseline result for universal semantic tagging.Comment: 9 pages, International Conference on Computational Semantics (IWCS

    Online Informative Path Planning for Active Classification on UAVs

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    We propose an informative path planning (IPP) algorithm for active classification using an unmanned aerial vehicle (UAV), focusing on weed detection in precision agriculture. We model the presence of weeds on farmland using an occupancy grid and generate plans according to information-theoretic objectives, enabling the UAV to gather data efficiently. We use a combination of global viewpoint selection and evolutionary optimization to refine the UAV's trajectory in continuous space while satisfying dynamic constraints. We validate our approach in simulation by comparing against standard "lawnmower" coverage, and study the effects of varying objectives and optimization strategies. We plan to evaluate our algorithm on a real platform in the immediate future.Comment: 7 pages, 4 figures, submission to International Symposium on Experimental Robotics 201

    World Guide to Technical Information and Documentation Services. United Nations Educational, Scientific and Cultural Organization. Paris: UNESCO, 1969. 287 pp. Hardbound, 6.00;paper,6.00; paper, 4.00 (available in U.S.A. from Unipub. Inc., P.O. Box 433, New York City, N.Y. 10016).

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    Excerpt: This very useful reference volume is a companion to UNESCO\u27s World Guide to Science Information and Documentation Services (1965). It lists and describes the principal centers in each country which provide technical information, either to all investigators or to a restricted clientele. 273 institutions in 73 countries have been included, with an informative yet concise report upon each source. A sampIe entry lists name of repository in the vernacular, English, French and acronym; addresses; brief history; staff; subject coverage; nature of library; nature of abstracting service; whether bibliographies, literature searches or translations are available; information about photoreproduction services; and methods of payment for services. The remarkable proliferation of information sources in science and technology makes such guides not only convenient but necessary
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