6,427 research outputs found

    Enhancing Perceptual Attributes with Bayesian Style Generation

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    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

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    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

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    Functions which are equivariant or invariant under the transformations of a compact linear group GG acting in an euclidean space â„œn\real^n, 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 GG-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

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    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

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    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 G=G={\bf O}3⊗_3\otimes{\bf U}1×_1\times . 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 GG-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

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    87NO13, 87NO15, 87JE6, 87NA93, 87NA93, 87NA97, 86KA82

    Avaliação preliminar da reação de cultivares de trigo a brusone em condições de campo.

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    bitstream/item/119385/1/FOL-06040.pd

    Avaliação de parâmetros ergonômicos : ruído e temperatura no posto operacional de tratores agrícolas

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    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 substituído pelas máquinas a fim de possibilitar o acesso a novas prácas na agricultura. A realização de uma operação segura com trator agrícola 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 ruído 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
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