5,058 research outputs found

    Counterexample Guided Inductive Optimization Applied to Mobile Robots Path Planning (Extended Version)

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    We describe and evaluate a novel optimization-based off-line path planning algorithm for mobile robots based on the Counterexample-Guided Inductive Optimization (CEGIO) technique. CEGIO iteratively employs counterexamples generated from Boolean Satisfiability (SAT) and Satisfiability Modulo Theories (SMT) solvers, in order to guide the optimization process and to ensure global optimization. This paper marks the first application of CEGIO for planning mobile robot path. In particular, CEGIO has been successfully applied to obtain optimal two-dimensional paths for autonomous mobile robots using off-the-shelf SAT and SMT solvers.Comment: 7 pages, 14rd Latin American Robotics Symposium (LARS'2017

    Morphology of Fine-Particle Monolayers Deposited on Nanopatterned Substrates

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    We study the effect of the presence of a regular substrate pattern on the irreversible adsorption of nanosized and colloid particles. Deposition of disks of radius r0r_0 is considered, with the allowed regions for their center attachment at the planar surface consisting of square cells arranged in a square lattice pattern. We study the jammed state properties of a generalized version of the random sequential adsorption model for different values of the cell size, aa, and cell-cell separation, bb. The model shows a surprisingly rich behavior in the space of the two dimensionless parameters α=a/2r0\alpha=a/2r_0 and β=b/2r0\beta=b/2r_0. Extensive Monte Carlo simulations for system sizes of 500×500500\times500 square lattice unit cells were performed by utilizing an efficient algorithm, to characterize the jammed state morphology.Comment: 11 pages, 10 figures, 3 table

    Estimação de parâmetros genéticos da produção leiteira e idade ao primeiro parto de vacas Pardo-Suíças por meio de inferência bayesiana.

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    Estimou-se a herdabilidade e a correlação genética para a produção de leite na primeira lactação (PL) e idade ao primeiro parto (IPP) de animais da raça Pardo-Suíça. Foram utilizados registros de 2.981 lactações, com partos ocorridos entre os anos de 1980 a 2002. Na estimação dos componentes de (co) variâncias foi utilizada a inferência Bayesiana, por meio de amostrador de Gibbs, com tamanho de cadeia de 1.500.000 rounds e período de queima de 500.000 rounds. A frequência de amostragem foi de 500 rounds. As médias estimadas para produção de leite e idade ao primeiro parto foram iguais a 5.347,47±1.849,13 kg e 29,65±4,51 meses, respectivamente. As estimativas de herdabilidade obtidas para a produção de leite e idade ao primeiro parto foram iguais a 0,23 e 0,18, respectivamente. A correlação genética entre elas foi igual a -0,31. As herdabilidades obtidas para as características de desempenho avaliadas indicam que ganhos genéticos satisfatórios podem ser obtidos no melhoramento para essas características e que a seleção simultânea para ambas as características pode ser realizad

    Collaboration networks from a large CV database: dynamics, topology and bonus impact

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    Understanding the dynamics of research production and collaboration may reveal better strategies for scientific careers, academic institutions and funding agencies. Here we propose the use of a large and multidisciplinar database of scientific curricula in Brazil, namely, the Lattes Platform, to study patterns of scientific production and collaboration. In this database, detailed information about publications and researchers are made available by themselves so that coauthorship is unambiguous and individuals can be evaluated by scientific productivity, geographical location and field of expertise. Our results show that the collaboration network is growing exponentially for the last three decades, with a distribution of number of collaborators per researcher that approaches a power-law as the network gets older. Moreover, both the distributions of number of collaborators and production per researcher obey power-law behaviors, regardless of the geographical location or field, suggesting that the same universal mechanism might be responsible for network growth and productivity.We also show that the collaboration network under investigation displays a typical assortative mixing behavior, where teeming researchers (i.e., with high degree) tend to collaborate with others alike. Finally, our analysis reveals that the distinctive collaboration profile of researchers awarded with governmental scholarships suggests a strong bonus impact on their productivity.Comment: 8 pages, 8 figure

    Random Sequential Adsorption: From Continuum to Lattice and Pre-Patterned Substrates

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    The random sequential adsorption (RSA) model has served as a paradigm for diverse phenomena in physical chemistry, as well as in other areas such as biology, ecology, and sociology. In the present work, we survey aspects of the RSA model with emphasis on the approach to and properties of jammed states obtained for large times in continuum deposition versus that on lattice substrates, and on pre-patterned surfaces. The latter model has been of recent interest in the context of efforts to use pre-patterning as a tool to improve selfassembly in micro- and nanoscale surface structure engineering

    Eigenvalue estimates for a class of elliptic differential operators in divergence form on Riemannian manifolds isometrically immersed in Euclidean space

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    In this paper, we obtain eigenvalue estimates for a larger class of elliptic differential operators in divergence form on a bounded domain in a complete Riemannian manifold isometrically immersed in Euclidean space. As an application, we give eigenvalue estimates in the Gaussian shrinking soliton, and we find a domain that makes the behavior of these estimates similar to the estimates for the case of the Laplacian. Moreover, we also give an answer to the generalized conjecture of P\'olya.Comment: 17 page
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