6,450 research outputs found
Enhancing Perceptual Attributes with Bayesian Style Generation
Deep learning has brought an unprecedented progress in computer vision and
significant advances have been made in predicting subjective properties
inherent to visual data (e.g., memorability, aesthetic quality, evoked
emotions, etc.). Recently, some research works have even proposed deep learning
approaches to modify images such as to appropriately alter these properties.
Following this research line, this paper introduces a novel deep learning
framework for synthesizing images in order to enhance a predefined perceptual
attribute. Our approach takes as input a natural image and exploits recent
models for deep style transfer and generative adversarial networks to change
its style in order to modify a specific high-level attribute. Differently from
previous works focusing on enhancing a specific property of a visual content,
we propose a general framework and demonstrate its effectiveness in two use
cases, i.e. increasing image memorability and generating scary pictures. We
evaluate the proposed approach on publicly available benchmarks, demonstrating
its advantages over state of the art methods.Comment: ACCV-201
Large portfolio losses: A dynamic contagion model
Using particle system methodologies we study the propagation of financial
distress in a network of firms facing credit risk. We investigate the
phenomenon of a credit crisis and quantify the losses that a bank may suffer in
a large credit portfolio. Applying a large deviation principle we compute the
limiting distributions of the system and determine the time evolution of the
credit quality indicators of the firms, deriving moreover the dynamics of a
global financial health indicator. We finally describe a suitable version of
the "Central Limit Theorem" useful to study large portfolio losses. Simulation
results are provided as well as applications to portfolio loss distribution
analysis.Comment: Published in at http://dx.doi.org/10.1214/08-AAP544 the Annals of
Applied Probability (http://www.imstat.org/aap/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Tools in the orbit space approach to the study of invariant functions: rational parametrization of strata
Functions which are equivariant or invariant under the transformations of a
compact linear group acting in an euclidean space , can profitably
be studied as functions defined in the orbit space of the group. The orbit
space is the union of a finite set of strata, which are semialgebraic manifolds
formed by the -orbits with the same orbit-type. In this paper we provide a
simple recipe to obtain rational parametrizations of the strata. Our results
can be easily exploited, in many physical contexts where the study of
equivariant or invariant functions is important, for instance in the
determination of patterns of spontaneous symmetry breaking, in the analysis of
phase spaces and structural phase transitions (Landau theory), in equivariant
bifurcation theory, in crystal field theory and in most areas where use is made
of symmetry adapted functions.
A physically significant example of utilization of the recipe is given,
related to spontaneous polarization in chiral biaxial liquid crystals, where
the advantages with respect to previous heuristic approaches are shown.Comment: Figures generated through texdraw package; revised version appearing
in J. Phys. A: Math. Ge
Motor regulation results in distal forces that bend partially disintegrated Chlamydomonas axonemes into circular arcs
The bending of cilia and flagella is driven by forces generated by dynein
motor proteins. These forces slide adjacent microtubule doublets within the
axoneme, the motile cytoskeletal structure. To create regular, oscilla- tory
beating patterns, the activities of the axonemal dyneins must be coordinated
both spatially and temporally. It is thought that coordination is mediated by
stresses or strains, which build up within the moving axoneme, and somehow
regulate dynein activity. While experimenting with axonemes subjected to mild
proteolysis, we observed pairs of doublets associate with each other and form
bends with almost constant curvature. By model- ing the statics of a pair of
filaments, we show that the activity of the motors concentrates at the distal
tips of the doublets. Furthermore, we show that this distribution of motor
activity accords with models in which curvature, or curvature-induced normal
forces, regulates the activity of the motors. These observations, together with
our theoretical analysis, provide evidence that dynein activity can be
regulated by curvature or normal forces, which may, therefore, play a role in
coordinating the beating of cilia and flagella
Geometric invariant theory approach to the determination of ground states of D-wave condensates in isotropic space
A complete and rigorous determination of the possible ground states for
D-wave pairing Bose condensates is presented, using a geometrical invariant
theory approach to the problem. The order parameter is argued to be a vector,
transforming according to a ten dimensional real representation of the group
{\bf O}{\bf U}. We determine the equalities
and inequalities defining the orbit space of this linear group and its symmetry
strata, which are in a one-to-one correspondence with the possible distinct
phases of the system. We find 15 allowed phases (besides the unbroken one),
with different symmetries, that we thoroughly determine. The group-subgroup
relations between bordering phases are pointed out. The perturbative sixth
degree corrections to the minimum of a fourth degree polynomial -invariant
free energy, calculated by Mermin, are also determined.Comment: 27 revtex pages, 2 figures, use of texdraw; minor changes in the
bibliography and in Table II
Cereal cyst nematode and time and method of sowing wheat
87NO13, 87NO15, 87JE6, 87NA93, 87NA93, 87NA97, 86KA82
Avaliação preliminar da reação de cultivares de trigo a brusone em condições de campo.
bitstream/item/119385/1/FOL-06040.pd
Avaliação de parâmetros ergonômicos : ruÃdo e temperatura no posto operacional de tratores agrÃcolas
O surgimento de máquinas e implementos utilizados na
agricultura mudaram definitivamente as técnicas de produção em todo o
mundo, de forma que o aumento da produtividade deste setor levou o
homem a ser substituÃdo pelas máquinas a fim de possibilitar o acesso a
novas prácas na agricultura. A realização de uma operação segura com
trator agrÃcola é essencial, sendo necessário que o operador tenha o
conhecimento de algumas medidas gerais de segurança. Este trabalho foi
realizado com o objevo de analisar o ruÃdo e a temperatura como risco
fisico no interior da cabine de um trator, considerando os limites de
tolerância permitidos pela Norma Regulamentadora 15 (Atividades e
Operações Insalubres) e 17 (Ergonomia).ABSTRACT : The emergence of machines and agricultural implements used
in agriculture had definitively changed the techniques of production in the
whole world, so that the increase of the productivity of this sector took
the man to be substituted for the machines in order to make possible the
access the new practices in agriculture. The accomplishment of a safe
operation with agricultural tractor is essential, being the necessary that
the operator has the knowledge of some general measures of security.
This work was accomplished with the aim to analyse noise and
temperature as physical risk in the interior of the cabin of a tractor,
Unhealthy considerando the limits of tolerance allowed by Regulator
Norm 15 (Activities and Operations) and 17 (Ergonomics).info:eu-repo/semantics/publishedVersio
- …