842 research outputs found

    Motivation, participation, and engagement in human work Interaction design literature

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    This position paper is aimed at presenting as discussion material at the CoPDA 2016 Workshop the preliminary results of a short review of the literature published by the HWID community in the last 10 years in four books. Specifically, the attention is posed on understanding the importance of motivation, participation, and engagement in Interaction Design projects for smart and pervasive workplaces

    Preface

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    Duality Theorems in Ergodic Transport

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    We analyze several problems of Optimal Transport Theory in the setting of Ergodic Theory. In a certain class of problems we consider questions in Ergodic Transport which are generalizations of the ones in Ergodic Optimization. Another class of problems is the following: suppose σ\sigma is the shift acting on Bernoulli space X={0,1}NX=\{0,1\}^\mathbb{N}, and, consider a fixed continuous cost function c:X×XRc:X \times X\to \mathbb{R}. Denote by Π\Pi the set of all Borel probabilities π\pi on X×XX\times X, such that, both its xx and yy marginal are σ\sigma-invariant probabilities. We are interested in the optimal plan π\pi which minimizes cdπ\int c d \pi among the probabilities on Π\Pi. We show, among other things, the analogous Kantorovich Duality Theorem. We also analyze uniqueness of the optimal plan under generic assumptions on cc. We investigate the existence of a dual pair of Lipschitz functions which realizes the present dual Kantorovich problem under the assumption that the cost is Lipschitz continuous. For continuous costs cc the corresponding results in the Classical Transport Theory and in Ergodic Transport Theory can be, eventually, different. We also consider the problem of approximating the optimal plan π\pi by convex combinations of plans such that the support projects in periodic orbits

    Logarithmic Corrections to N=2 Black Hole Entropy: An Infrared Window into the Microstates

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    Logarithmic corrections to the extremal black hole entropy can be computed purely in terms of the low energy data -- the spectrum of massless fields and their interaction. The demand of reproducing these corrections provides a strong constraint on any microscopic theory of quantum gravity that attempts to explain the black hole entropy. Using quantum entropy function formalism we compute logarithmic corrections to the entropy of half BPS black holes in N=2 supersymmetric string theories. Our results allow us to test various proposals for the measure in the OSV formula, and we find agreement with the measure proposed by Denef and Moore if we assume their result to be valid at weak topological string coupling. Our analysis also gives the logarithmic corrections to the entropy of extremal Reissner-Nordstrom black holes in ordinary Einstein-Maxwell theory.Comment: LaTeX file, 66 page

    Valor nutritivo de silagens de capim-elefante (Pennisetum purpureum, Shum) com feno de gliricídia (Gliricidia sepium(Jacq.) Walp)

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    O trabalho foi realizado com o objetivo de avaliar a composição químico-bromatológica de silagem de capim-elefante (Pennisetum purpureum, Shum) com adição de diferentes proporções de feno de gliricídia (Gliricidia sepium (Jacq.) Walp), utilizando-se mini-silos experimentais em delineamento inteiramente casualizado, com cinco tratamentos: 100% capim-elefante, 95% de capim-elefante e 5% de feno de gliricídia, 90% de capim-elefante e 10% de feno de gliricídia, 80% de capim-elefante e 20% de feno de gliricídia e 60% de capim-elefante e 40% de feno de gliricídia com cinco repetições por tratamento. Os silos foram abertos com 28 dias após a ensilagem, em que foram determinados os teores de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), hemicelulose (HEM), celulose (CEL), lignina (LG), extrato etéreo (EE), matéria mineral (MM) e carboidratos totais (CHOT). As variáveis MS, CEL e EE apresentaram respostas lineares (P<0,05) ao aumento nos teores de feno adicionados as silagens de capim-elefante e as variáveis PB, FDN, FDA, HEM, LG e CHOT apresentaram efeito quadrático (P<0,05). Com base nos resultados obtidos, pode-se concluir que a adição de feno de gliricídia na ensilagem do capim elefante melhorou seu valor nutricional

    O período da contaminação com petróleo influencia a rebrota de Echinochloa polystachya (H.B.K.) Hitchcock em solo de várzea da Amazônia central?

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    Several factors may influence the impact of oil on the environment. However, although it is understood that the effect of pollutants may change throughout the year according to seasonal variations in environmental parameters, this effect is poorly studied in the tropical region. The effects of Urucu's crude oil on the vegetative propagation and growth of Echinochloa polystachya were evaluated in a 63 days period, in two experiments, "A" (July-September) and "B" (September-November) planting the species in a greenhouse. In both experiments parts of stems were placed in 2 L of várzea soil contaminated by 6 oil doses, ranging from 0 to 0.231 L oil m-2 soil. In response to dosage increase there was a decrease of total biomass, ratio of live /total biomass, the leaf length and number of leaves. The period of planting influenced the response of plants to the dosage applied due to climate change, with negative effects in the "B" period of higher temperatures. We concluded that the exposure period influence the vegetative propagation and growth of the seedlings, being a spill in the period of the higher temperatures more dangerous for this specie

    Quenching of Meridional Circulation in Flux Transport Dynamo Models

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    Guided by the recent observational result that the meridional circulation of the Sun becomes weaker at the time of the sunspot maximum, we have included a parametric quenching of the meridional circulation in solar dynamo models such that the meridional circulation becomes weaker when the magnetic field at the base of the convection zone is stronger. We find that a flux transport solar dynamo tends to become unstable on including this quenching of meridional circulation if the diffusivity in the convection zone is less than about 2 * 10^{11} cm^2/s. The quenching of alpha, however, has a stabilizing effect and it is possible to stabilize a dynamo with low diffusivity with sufficiently strong alpha-quenching. For dynamo models with high diffusivity, the quenching of meridional circulation does not produce a large effect and the dynamo remains stable. We present a solar-like solution from a dynamo model with diffusivity 2.8 * 10^{12} cm^2/s in which the quenching of meridional circulation makes the meridional circulation vary periodically with solar cycle as observed and does not have any other significant effect on the dynamo.Comment: Consistent with the published version. Solar Physics, in pres

    Search for Λc+pK+π\Lambda_c^+ \to p K^+ \pi^- and Ds+K+K+πD_s^+ \to K^+ K^+ \pi^- Using Genetic Programming Event Selection

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    We apply a genetic programming technique to search for the double Cabibbo suppressed decays Λc+pK+π\Lambda_c^+ \to p K^+ \pi^- and Ds+K+K+πD_s^+ \to K^+ K^+ \pi^-. We normalize these decays to their Cabibbo favored partners and find BR(\text{BR}(\Lambda_c^+ \to p K^+ \pi^-)/BR()/\text{BR}(\Lambda_c^+ \to p K^- \pi^+)=(0.05±0.26±0.02)) = (0.05 \pm 0.26 \pm 0.02)% and BR(\text{BR}(D_s^+ \to K^+ K^+ \pi^-)/BR()/\text{BR}(D_s^+ \to K^+ K^- \pi^+)=(0.52±0.17±0.11)) = (0.52\pm 0.17\pm 0.11)% where the first errors are statistical and the second are systematic. Expressed as 90% confidence levels (CL), we find <0.46< 0.46 % and <0.78 < 0.78% respectively. This is the first successful use of genetic programming in a high energy physics data analysis.Comment: 10 page

    A Non-parametric Approach to the D+ to K*0bar mu+ nu Form Factors

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    Using a large sample of D+ -> K- pi+ mu+ nu decays collected by the FOCUS photoproduction experiment at Fermilab, we present the first measurements of the helicity basis form factors free from the assumption of spectroscopic pole dominance. We also present the first information on the form factor that controls the s-wave interference discussed in a previous paper by the FOCUS collaboration. We find reasonable agreement with the usual assumption of spectroscopic pole dominance and measured form factor ratios.Comment: 14 pages, 5 figures, and 2 tables. We updated the previous version by changing some words, removing one plot, and adding two tables. These changes are mostly stylisti

    Dalitz plot analysis of D_s+ and D+ decay to pi+pi-pi+ using the K-matrix formalism

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    FOCUS results from Dalitz plot analysis of D_s+ and D+ to pi+pi-pi+ are presented. The K-matrix formalism is applied to charm decays for the first time to fully exploit the already existing knowledge coming from the light-meson spectroscopy experiments. In particular all the measured dynamics of the S-wave pipi scattering, characterized by broad/overlapping resonances and large non-resonant background, can be properly included. This paper studies the extent to which the K-matrix approach is able to reproduce the observed Dalitz plot and thus help us to understand the underlying dynamics. The results are discussed, along with their possible implications on the controversial nature of the sigma meson.Comment: To be submitted to Phys.Lett.B A misprint corrected in formula
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