1,146 research outputs found

    Duality with expanding maps and shrinking maps, and its applications to Gauss maps

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    We study expanding maps and shrinking maps of subvarieties of Grassmann varieties in arbitrary characteristic. The shrinking map was studied independently by Landsberg and Piontkowski in order to characterize Gauss images. To develop their method, we introduce the expanding map, which is a dual notion of the shrinking map and is a generalization of the Gauss map. Then we give a characterization of separable Gauss maps and their images, which yields results for the following topics: (1) Linearity of general fibers of separable Gauss maps; (2) Generalization of the characterization of Gauss images; (3) Duality on one-dimensional parameter spaces of linear subvarieties lying in developable varieties.Comment: 28 pages, v3: added some examples, v2: the title has been changed from v1 "Linearity of general fibers of separable Gauss maps

    Progress on the hybrid gun project at UCLA

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    UCLA/INFN-LNF/Univ. Rome has been developing the hybrid gun which has an RF gun and a short linac for velocity bunching in one structure. After the cavity was manufactured at INFN-LNF in 2012, tests of the gun was carried out at UCLA. The field in the standing wave part was 20 % smaller than the simulation but the phase advance was fine. The cavity was commissioned successfully up to 13 MW. The beam test was performed at 11.5 MW and demonstrated the bunch compression

    Preparation of Short-life Berkelium Tracers by 241Am(α,xn) or 243Am(α,xn) Reactions

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    開始ページ、終了ページ: 冊子体のページ付

    The Hard Life: A Pedagogical Experience in Industrial Design

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    Thispaperseekstoanalyzeanddiscussaredesignprojectdeveloped by students of master’s degree in industrial design. Based on the book The Hard Life, from English designer Jasper Morrison, the briefing proposed the devel- opment of concepts for new products inspired by the selection of objects in the book, and respective written interpretations. It seeks to explore the dialogue between the original objects – their use, Morrison’s interpretation - and the reinterpretation made by the students considering the current material culture. Accompanied and coordinated with Bisarro, contemporary studio dedicated to the artisan production of small series in Bisalhães black clay, UNESCO Immaterial Cultural Heritage, the project seeks to explore the boundaries and common ground between memory and contemporary times. More than the results, it is intended to discuss proposals and approaches, from functional interpretations, formal inspiration, to the appropriation of affordance and gesture.info:eu-repo/semantics/publishedVersio

    Characterization of the QUartz Photon Intensifying Detector (QUPID) for Noble Liquid Detectors

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    Dark Matter and Double Beta Decay experiments require extremely low radioactivity within the detector materials. For this purpose, the University of California, Los Angeles and Hamamatsu Photonics have developed the QUartz Photon Intensifying Detector (QUPID), an ultra-low background photodetector based on the Hybrid Avalanche Photo Diode (HAPD) and entirely made of ultraclean synthetic fused silica. In this work we present the basic concept of the QUPID and the testing measurements on QUPIDs from the first production line. Screening of radioactivity at the Gator facility in the Laboratori Nazionali del Gran Sasso has shown that the QUPIDs safely fulfill the low radioactive contamination requirements for the next generation zero background experiments set by Monte Carlo simulations. The quantum efficiency of the QUPID at room temperature is > 30% at the xenon scintillation wavelength. At low temperatures, the QUPID shows a leakage current less than 1 nA and a global gain of 10^5. In these conditions, the photocathode and the anode show > 95% linearity up to 1 uA for the cathode and 3 mA for the anode. The photocathode and collection efficiency are uniform to 80% over the entire surface. In parallel with single photon counting capabilities, the QUPIDs have a good timing response: 1.8 +/- 0.1 ns rise time, 2.5 +/- 0.2 ns fall time, 4.20 +/- 0.05 ns pulse width, and 160 +/- 30 ps transit time spread. The QUPIDs have also been tested in a liquid xenon environment, and scintillation light from 57Co and 210Po radioactive sources were observed.Comment: 15 pages, 22 figure

    17 ways to say yes:Toward nuanced tone of voice in AAC and speech technology

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    People with complex communication needs who use speech-generating devices have very little expressive control over their tone of voice. Despite its importance in human interaction, the issue of tone of voice remains all but absent from AAC research and development however. In this paper, we describe three interdisciplinary projects, past, present and future: The critical design collection Six Speaking Chairs has provoked deeper discussion and inspired a social model of tone of voice; the speculative concept Speech Hedge illustrates challenges and opportunities in designing more expressive user interfaces; the pilot project Tonetable could enable participatory research and seed a research network around tone of voice. We speculate that more radical interactions might expand frontiers of AAC and disrupt speech technology as a whole

    THE EFFECT OF OXEN ON AGRICULTURAL PRODUCTIVITY AND FARM INCOME IN NICARAGUA

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    This study1 uses survey data to assess the effect of oxen as draft animals on agricultural productivity and farm agricultural income in Nicaragua during the year 2017. The results suggest that farms that use oxen to plow the land have higher bean productivity than farms that use stick to plant crops. On average, using oxen increases farm’s bean output by 7.75 100-pound bags, and hiring oxen increases farm’s bean output by 8.5 100-pound bags. Also, using or hiring oxen increases total farm planted area. The main finding about the effect of oxen to plow the land through farm planted area on agricultural farm gross income suggests that using oxen to plow the land increases agricultural farm gross income by 18.13 percent, and that hiring oxen increases agricultural farm gross income by 25.55 percent

    Structure and dynamics in protic ionic liquids: a combined optical Kerr-effect and dielectric relaxation spectroscopy study

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    The structure and dynamics of ionic liquids (ILs) are unusual due to the strong interactions between the ions and counter ions. These microscopic properties determine the bulk transport properties critical to applications of ILs such as advanced fuel cells. The terahertz dynamics and slower relaxations of simple alkylammonium nitrate protic ionic liquids (PILs) are here studied using femtosecond optical Kerr-effect spectroscopy, dielectric relaxation spectroscopy, and terahertz time-domain spectroscopy. The observed dynamics give insight into more general liquid behaviour while comparison with glass-forming liquids reveals an underlying power-law decay and relaxation rates suggest supramolecular structure and nanoscale segregation
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