12,541 research outputs found
Quantiles for Fractions and Other Mixed Data
This paper studies the estimation of quantile regression for fractional data, focusing on the case where there are mass-points at zero or/and one. More generally, we propose a simple strategy for the estimation of the conditional quantiles of data from mixed distributions, which combines standard results on the estimation of censored and Box-Cox quantile regressions. The implementation of the proposed method is illustrated using a well-known dataset.
Crystal engineering using functionalized adamantane
We performed a first principles investigation on the structural, electronic,
and optical properties of crystals made of chemically functionalized adamantane
molecules. Several molecular building blocks, formed by boron and nitrogen
substitutional functionalizations, were considered to build zincblende and
wurtzite crystals, and the resulting structures presented large bulk moduli and
cohesive energies, wide and direct bandgaps, and low dielectric constants
(low- materials). Those properties provide stability for such
structures up to room temperature, superior to those of typical molecular
crystals. This indicates a possible road map for crystal engineering using
functionalized diamondoids, with potential applications ranging from space
filling between conducting wires in nanodevices to nano-electro-mechanical
systems
BRS Kurumi and BRS Capiaçu - New elephant grass cultivars for grazing and cut-and-carry system.
Cultivar BRS Kurumi is characterized by short plant height, short internodes, high dry matter production (29.25 t ha-1yr-1), has a high nutritional value and is recommended for the cut-and-carry system or grazing. Cultivar BRS Capiaçu, indicated for silage and the cut-and-carry system, has tall upright growth, high dry matter production (49.75 t ha-1yr-1), good forage quality, is lodging-resistant and suitable for mechanical harvesting. Both cultivars are vegetatively propagated by stem cuttings
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