11,621 research outputs found
Using a Logic Programming Framework to Control Database Query Dialogues in Natural Language
We present a natural language question/answering system to interface the University of Évora databases that uses clarification dialogs in order to clarify user questions. It was developed in an integrated logic programming framework, based on constraint logic programming using the GnuProlog(-cx) language [2,11] and the ISCO framework [1]. The use of this LP framework allows the integration of Prolog-like inference mechanisms with classes and inheritance, constraint solving algorithms and provides the connection with relational databases, such as PostgreSQL. This system focus on the questions’ pragmatic analysis, to handle ambiguity, and on an efficient dialogue mechanism, which is able to place relevant questions to clarify the user intentions in a straightforward manner. Proper Nouns resolution and the pp-attachment problem are also handled.
This paper briefly presents this innovative system focusing on its ability to correctly determine the user intention through its dialogue capability
Gauge Fluctuations in Superconducting Films
In this paper we consider a superconducting film modeled by the
Ginzburg-Landau model, confined between two parallel planes a distance
apart from one another. Our approach is based on the Gaussian effective
potential in the transverse unitarity gauge, which allows to treat gauge
contributions in a compact form. Using techniques from dimensional and
-function regularizations, modified by the confinement conditions, we
investigate the critical temperature as a function of the film thickness .
The contributions from the scalar self-interaction and from the gauge
fluctuations are clearly identified. The model suggests the existence of a
minimal critical thickness below which superconductivity is suppressed.Comment: 6 pages Revtex, no figure
Bar pattern speed evolution over the last 7 Gyr
The tumbling pattern of a bar is the main parameter characterising its
dynamics. From numerical simulations, its evolution since bar formation is
tightly linked to the dark halo in which the bar is formed through dynamical
friction and angular momentum exchange. Observational measurements of the bar
pattern speed with redshift can restrict models of galaxy formation and bar
evolution. We aim to determine, for the first time, the bar pattern speed
evolution with redshift based on morphological measurements. We have selected a
sample of 44 low inclination ringed galaxies from the SDSS and COSMOS surveys
covering the redshift range 0 <z< 0.8 to investigate the evolution of the bar
pattern speed. We have derived morphological ratios between the deprojected
outer ring radius (R_{ring}) and the bar size (R_{bar}). This quantity is
related to the parameter {\cal R}=R_{CR}/R_{bar} used for classifiying bars in
slow and fast rotators, and allow us to investigate possible differences with
redshift. We obtain a similar distribution of at all redshifts. We do not
find any systematic effect that could be forcing this result. The results
obtained here are compatible with both, the bulk of the bar population (~70%)
being fast-rotators and no evolution of the pattern speed with redshift. We
argue that if bars are long-lasting structures, the results presented here
imply that there has not been a substantial angular momentum exchange between
the bar and halo, as predicted by numerical simulations. In consequence, this
might imply that the discs of these high surface-brightness galaxies are
maximal.Comment: Accepted for publication in A&
Deep spectroscopic luminosity function of Abell 85: no evidence for a steep upturn of the faint-end slope
We present a new deep determination of the spectroscopic LF within the virial
radius of the nearby and massive Abell\,85 (A85) cluster down to the dwarf
regime (M* + 6) using VLT/VIMOS spectra for galaxies with m mag and mag arcsec. The
resulting LF from 438 cluster members is best modelled by a double Schechter
function due to the presence of a statistically significant upturn at the
faint-end. The amplitude of this upturn (),
however, is much smaller than that of the SDSS composite photometric cluster LF
by Popesso et al. 2006, -2. The faint-end slope of the LF in
A85 is consistent, within the uncertainties, with that of the field. The red
galaxy population dominates the LF at low luminosities, and is the main
responsible for the upturn. The fact that the slopes of the spectroscopic LFs
in the field and in a cluster as massive as A85 are similar suggests that the
cluster environment does not play a major role in determining the abundance of
low-mass galaxies.Comment: 6 pages, 4 figures, accepted at MNRAS lette
Modelos de composteira para compostagem de aves mortas.
bitstream/item/56384/1/publicacao-ct-57.pd
Temperatura superficial de isolantes térmicos e cortinas para a produção animal.
Projeto: 03.07.09.049
Equipamentos alternativos na obtenção de farinha de resíduos de tambaqui (Colossoma macropomum).
O tambaqui (Colossoma macropomum) é o segundo maior peixe de escama da América, superado apenas pelo pirarucu. Nativo da bacia Amazônica, atualmente vem ganhando destaque na aquicultura familiar da Região Norte, como no Estado do Pará, onde seu consumo vem aumentando gradativamente, principalmente na forma de filés. No entanto, o processo de filetamento de pescado gera um volume de resíduos superior a 50%, que pode se tornar um importante poluente se não tiver um manuseio adequado. Estes resíduos possuem alto teor de proteína e de outros nutrientes que tem grande demanda em outros setores, como na elaboração de farinhas para ração animal, por exemplo. Contudo, as instalações iniciais para o processamento de farinhas é um tanto quanto oneroso. O objetivo deste foi, através da adaptação de utensílios e equipamentos, elaborar um processo em escala piloto para aproveitamento de resíduos de tambaqui que pode ser realizado por pequenos e médios produtores, para produção de farinha e consequente incorporação em suas rações. Com teor de 8% de lipídios e 61% de proteína, o produto elaborado em pequena escala enquadrouse nos padrões de farinhas da RIISPOA e ANFAR
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