3,589 research outputs found
AnĂĄlise do complexo pecuĂĄrio no nordeste paraense.
bitstream/item/51782/1/documentos180001.pd
Unbiased Shape Compactness for Segmentation
We propose to constrain segmentation functionals with a dimensionless,
unbiased and position-independent shape compactness prior, which we solve
efficiently with an alternating direction method of multipliers (ADMM).
Involving a squared sum of pairwise potentials, our prior results in a
challenging high-order optimization problem, which involves dense (fully
connected) graphs. We split the problem into a sequence of easier sub-problems,
each performed efficiently at each iteration: (i) a sparse-matrix inversion
based on Woodbury identity, (ii) a closed-form solution of a cubic equation and
(iii) a graph-cut update of a sub-modular pairwise sub-problem with a sparse
graph. We deploy our prior in an energy minimization, in conjunction with a
supervised classifier term based on CNNs and standard regularization
constraints. We demonstrate the usefulness of our energy in several medical
applications. In particular, we report comprehensive evaluations of our fully
automated algorithm over 40 subjects, showing a competitive performance for the
challenging task of abdominal aorta segmentation in MRI.Comment: Accepted at MICCAI 201
Luminescent coordination polymers based on CaÂČâș and octahedral cluster anions [{MâClâ±â}Clá”â}ÂČâ» (M = Mo, W) : synthesis and thermal stability studies
Luminescent coordination polymers (CPs) based of inexpensive stable precursors are attractive materials for applications. Here we report the synthesis and evaluation of the stability and photophysical characteristics of the first examples of phosphorescent CPs based on octahedral molybdenum and tungsten cluster anions. Specifically 1D CP trans-[{Ca(OPPhâ)â}{{MâClâ±â}Clá”â}]â (M = Mo, W) can be obtained either directly at increased temperature or via intermediate phases [cis-Ca(OPPhâ)â(HâO)â][{MâClâ±â}Clá”â]â2CHâCN that are stable at room-temperature, but convert to the titled CP at temperatures above 100 °C
O processo de desenvolvimento e nĂvel tecnolĂłgico de culturas perenes: o caso da pimenta-do-reino no nordeste paraense.
bitstream/item/58426/1/CPATU-DOC-23.pd
Production of Focused Neutron Beam Using Heavy Ion Reaction
éć§ăăŒăžăç”äșăăŒăž: ććäœăźăăŒăžä»
Random walks on finite lattice tubes
Exact results are obtained for random walks on finite lattice tubes with a
single source and absorbing lattice sites at the ends. Explicit formulae are
derived for the absorption probabilities at the ends and for the expectations
that a random walk will visit a particular lattice site before being absorbed.
Results are obtained for lattice tubes of arbitrary size and each of the
regular lattice types; square, triangular and honeycomb. The results include an
adjustable parameter to model the effects of strain, such as surface curvature,
on the surface diffusion. Results for the triangular lattice tubes and the
honeycomb lattice tubes model diffusion of adatoms on single walled zig-zag
carbon nano-tubes with open ends.Comment: 22 pages, 4 figure
Hypersurface homogeneous locally rotationally symmetric spacetimes admitting conformal symmetries
All hypersurface homogeneous locally rotationally symmetric spacetimes which
admit conformal symmetries are determined and the symmetry vectors are given
explicitly. It is shown that these spacetimes must be considered in two sets.
One set containing Ellis Class II and the other containing Ellis Class I, III
LRS spacetimes. The determination of the conformal algebra in the first set is
achieved by systematizing and completing results on the determination of CKVs
in 2+2 decomposable spacetimes. In the second set new methods are developed.
The results are applied to obtain the classification of the conformal algebra
of all static LRS spacetimes in terms of geometrical variables. Furthermore all
perfect fluid nontilted LRS spacetimes which admit proper conformal symmetries
are determined and the physical properties some of them are discussed.Comment: 15 pages; to appear in Classical Quantum Gravity; some misprints in
Tables 3,5 and in section 4 correcte
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