1,755 research outputs found

    Antenna feed system for receiving circular polarization and transmitting linear polarization

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    An object is to provide for receiving a circularly polarized signal from an antenna feed (10) connected to orthogonally spaced antenna elements (11, 12, 13, 14) and for transmitting a linearly polarized signal through the same feed without switches, and without suffering a 3 dB polarization mismatch loss, using an arrangement of hybrid junctions. The arrangement is comprised of two dividing hybrid junctions (15, 16), each connected to a different pair of antenna elements and a summing hybrid junction (17). In one embodiment, a receiver (18) is connected to the summing hybrid junction directly. A diplexer (19a or 19b) is used to connect a transmitter (20a or 20b) to only one pair of antenna elements. In an alternative embodiment, designated left and right circularly polarized (LCP and RCP) transmitters (21, 22) are connected to the summing hybrid junction by separate diplexers (23, 24), and separate LCP and RCP sensitive receivers (25, 26) are connected to the diplexers in order to transmit linearly polarized signals using all four antenna elements while receiving circularly polarized signals as before. An orthomode junction (30) and horn antenna (32) may replace the two dividing hybrid junctions (15, 16) and antenna feed (10)

    Betriebliches BiodiversitĂ€tsmanagement in regionalen landwirtschaftlichen Lieferketten – eine empirische Fallstudienforschung

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    Die BiodiversitĂ€t ist die Grundvoraussetzung fĂŒr das langfristige Wohlergehen der Menschen. Der Sektor Landwirtschaft und ErnĂ€hrung trĂ€gt maßgeblich zum welt-weiten BiodiversitĂ€tsverlust bei und verfĂŒgt umgekehrt ĂŒber ein enormes Gestal-tungspotenzial in Richtung Nachhaltigkeit. Gleichzeitig wĂ€chst das Verbraucherbe-wusstsein fĂŒr regionale Herkunft und QualitĂ€t. In diesem Spannungsfeld gewinnt das Management der BiodiversitĂ€t im Lebensmittelsektor, gerade auf der Ebene von Regionen und insbesondere fĂŒr kleine und mittlere Unternehmen (KMU), immer mehr an Relevanz. Die Lieferkette ‚vom Getreide zum Brot‘ ist hierbei in vielfĂ€ltiger Weise ein Forschungsgegenstand mit besonderem Erkenntnisinteresse.1 Um das komplexe Themenfeld ‚BiodiversitĂ€t‘ fĂŒr betriebliche Entscheidungen nutz-bar zu machen, braucht es geeignete Indikatoren. Zwar finden sich in der Literatur zahlreiche ZugĂ€nge; niederschwellige und unternehmerfreundliche Instrumente zur Bewertung der Auswirkungen auf die biologische Vielfalt in Lieferketten der Agrar- und Lebensmittelversorgung existieren bisher jedoch keine. Die vorliegende Dissertation soll diese ForschungslĂŒcke schließen. Ziel ist es, ein Be-wertungsinstrument auf Basis praktikabler, aussagekrĂ€ftiger und branchenrelevan-ter Indikatoren zur Abbildung der ‚betrieblichen BiodiversitĂ€tsleistung‘ (BBL) land-wirtschaftlicher Betriebe zu erarbeiten und anhand einer Auswahl von Unterneh-men modellhaft zu erproben. Aus den empirischen Ergebnissen werden Manage-mentempfehlungen fĂŒr nachgelagerte Akteure in der Lieferkette (MĂŒhlen, BĂ€cke-reien) abgeleitet und Perspektiven fĂŒr die weiterfĂŒhrende Forschung eröffnet. Um dieses Ziel zu erreichen, wird eine Kombination qualitativer und quantitativer Methoden (mixed methods) als sinnvoll erachtet. Mit Fokus auf das Untersuchungs-gebiet Ostsachsen besteht die Feldarbeit aus einer (1) qualitativ-explorativen Vor-studie (Experteninterviews, Pretests), (2) einer quantitativen Hauptuntersuchung durch teilstandardisierte Befragungen von Landwirten und (3) qualitativ-vertiefen-den Fallstudien auf Basis von Vor-Ort-Interviews mit ausgewĂ€hlten Landwirten und Landwirtinnen und weiteren verarbeitenden Betrieben. Im Folgenden werden die Problem- und Zielstellung, die Forschungsfragen, der Stand der Forschung sowie der Aufbau der Arbeit nĂ€her erlĂ€utert

    Zusatzstoff-Dossiers. Alternativen zum Einsatz von Zusatzstoffen in der Verarbeitung von biologischen Lebensmitteln sowie Vermeidung bzw. Verringerung des Einsatzes von Zusatzstoffen zur Sicherung und Verbesserung der QualitÀt ökologischer Lebensmittel

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    Alle fĂŒr die Verarbeitung ökologischer Erzeugnisse bereits zugelassenen Zusatzstoffe wurden anhand der Kriterien der EU fĂŒr die Zulassung von neuen Zusatzstoffen sowie der Erfahrungen der VerbĂ€nde und Industrie geprĂŒft und beurteilt. Als Ergebnis wurde eine Dossiersammlung erarbeitet. Jeder fĂŒr die ökologische Verarbeitung zugelassene Zusatzstoff wird in einem eigenen Kapitel („Dossier“) vorgestellt

    Oscilatory modules

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    Developing the ideas of Bressler and Soibelman and of Karabegov, we introduce a notion of an oscillatory module on a symplectic manifold which is a sheaf of modules over the sheaf of deformation quantization algebras with an additional structure. We compare the category of oscillatory modules on a torus to the Fukaya category as computed by Polishchuk and Zaslow.Comment: To appear in the proceedings of Moshe Flato Memorial Conference, November, 2008, Ben Gurion Universit

    Analytical and computational advances, opportunities, and challenges in marine organic biogeochemistry in an era of "Omics"

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    © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Steen, A. D., Kusch, S., Abdulla, H. A., Cakic, N., Coffinet, S., Dittmar, T., Fulton, J. M., Galy, V., Hinrichs, K., Ingalls, A. E., Koch, B. P., Kujawinski, E., Liu, Z., Osterholz, H., Rush, D., Seidel, M., Sepulveda, J., & Wakeham, S. G. Analytical and computational advances, opportunities, and challenges in marine organic biogeochemistry in an era of "Omics". Frontiers in Marine Science, 7, (2020): 718, doi:10.3389/fmars.2020.00718.Advances in sampling tools, analytical methods, and data handling capabilities have been fundamental to the growth of marine organic biogeochemistry over the past four decades. There has always been a strong feedback between analytical advances and scientific advances. However, whereas advances in analytical technology were often the driving force that made possible progress in elucidating the sources and fate of organic matter in the ocean in the first decades of marine organic biogeochemistry, today process-based scientific questions should drive analytical developments. Several paradigm shifts and challenges for the future are related to the intersection between analytical progress and scientific evolution. Untargeted “molecular headhunting” for its own sake is now being subsumed into process-driven targeted investigations that ask new questions and thus require new analytical capabilities. However, there are still major gaps in characterizing the chemical composition and biochemical behavior of macromolecules, as well as in generating reference standards for relevant types of organic matter. Field-based measurements are now routinely complemented by controlled laboratory experiments and in situ rate measurements of key biogeochemical processes. And finally, the multidisciplinary investigations that are becoming more common generate large and diverse datasets, requiring innovative computational tools to integrate often disparate data sets, including better global coverage and mapping. Here, we compile examples of developments in analytical methods that have enabled transformative scientific advances since 2004, and we project some challenges and opportunities in the near future. We believe that addressing these challenges and capitalizing on these opportunities will ensure continued progress in understanding the cycling of organic carbon in the ocean.The Hanse-Wissenschaftskolleg Delmenhorst, Germany, sponsored the “Marine Organic Biogeochemistry” workshop in April 2019, of which this working group report was a part. The workshop was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – project number: 422798570. The Geochemical Society provided additional funding for the conference. AS was supported by DOE grant DE-SC0020369

    Numerical hydrodynamics in general relativity

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    The current status of numerical solutions for the equations of ideal general relativistic hydrodynamics is reviewed. With respect to an earlier version of the article the present update provides additional information on numerical schemes and extends the discussion of astrophysical simulations in general relativistic hydrodynamics. Different formulations of the equations are presented, with special mention of conservative and hyperbolic formulations well-adapted to advanced numerical methods. A large sample of available numerical schemes is discussed, paying particular attention to solution procedures based on schemes exploiting the characteristic structure of the equations through linearized Riemann solvers. A comprehensive summary of astrophysical simulations in strong gravitational fields is presented. These include gravitational collapse, accretion onto black holes and hydrodynamical evolutions of neutron stars. The material contained in these sections highlights the numerical challenges of various representative simulations. It also follows, to some extent, the chronological development of the field, concerning advances on the formulation of the gravitational field and hydrodynamic equations and the numerical methodology designed to solve them.Comment: 105 pages, 12 figures. The full online-readable version of this article, including several animations, will be published in Living Reviews in Relativity at http://www.livingreviews.or

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð„with constraintsð ð ð„ „ ðandðŽð„ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

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    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI
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