Randomized pick-freeze for sparse Sobol indices estimation in high dimension

This article investigates a new procedure to estimate the influence of each variable of a given function defined on a high-dimensional space. More precisely, we are concerned with describing a function of a large number $p$ of parameters that depends only on a small number $s$ of them. Our proposed method is an unconstrained $\ell_{1}$-minimization based on the Sobol's method. We prove that, with only $\mathcal O(s\log p)$ evaluations of $f$, one can find which are the relevant parameters

Deep Neural Networks for Anatomical Brain Segmentation

We present a novel approach to automatically segment magnetic resonance (MR) images of the human brain into anatomical regions. Our methodology is based on a deep artificial neural network that assigns each voxel in an MR image of the brain to its corresponding anatomical region. The inputs of the network capture information at different scales around the voxel of interest: 3D and orthogonal 2D intensity patches capture the local spatial context while large, compressed 2D orthogonal patches and distances to the regional centroids enforce global spatial consistency. Contrary to commonly used segmentation methods, our technique does not require any non-linear registration of the MR images. To benchmark our model, we used the dataset provided for the MICCAI 2012 challenge on multi-atlas labelling, which consists of 35 manually segmented MR images of the brain. We obtained competitive results (mean dice coefficient 0.725, error rate 0.163) showing the potential of our approach. To our knowledge, our technique is the first to tackle the anatomical segmentation of the whole brain using deep neural networks

Subversive blood ties: gothic decadence in three characters from murnau's and coppola's renderings of bram stoker's dracula

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Programa de Pós-Graduação em Letras/Inglês e Literatura Correspondente, Florianópolis, 2013Esta dissertação consiste em investigar a construção do tema da decadência Gótica em Drácula de Bram Stoker e duas adaptações fílmicas do romance - Nosferatu, de Friedrich Wilhelm Murnau, e Drácula de Bram Stoker, de Francis Ford Coppola - tendo como centro da análise como três personagens - Drácula, Jonathan Harker e Mina Harker - se relacionam com tal tema. A decadência Gótica é um padrão literário do contexto fin-de-siècle da sociedade vitoriana inspirada pela crise social que acontecia na Inglaterra no fim do século XIX (Punter e Byron 39-40). Autores como Bram Stoker escreveram histórias que refletiam medos morais e sociais da sociedade vitoriana, retratando imagens de monstros que representavam a transgressão de fronteiras morais e sexuais estabelecidas pelas tradições vitorianas (Botting 88). Tendo tal discussão em mente, este estudo busca conectar a retratação de tal tema do romance às adaptações, também utilizando uma análise fílmica para identificar técnicas que destacam a representação do tema relacionado aos três personagens, finalmente ligando tal tema a crises e confusões sociais que aconteciam nos contextos de ambos os filmes.Abstract : The present dissertation consists of an investigation of the construction of the Gothic theme of decadence in Bram Stoker's Dracula and two film adaptations of the novel - Friedrich Wilhelm Murnau's Nosferatu and Francis Ford Coppola's Bram Stoker's Dracula - having as the centre of analysis how three characters - Dracula, Jonathan Harker and Mina Harker - relate to that theme. The Gothic decadence is a literary motif from the fin-de-siècle context of the Victorian Era inspired by the social crisis that took place in England in the late nineteenth century (Punter and Byron 39-40). Authors like Bram Stoker wrote stories that reflected moral and social fears of the Victorian society, depicting images of monsters that represented the crossing of moral and sexual boundaries established by the Victorian traditions (Botting 88). Bearing that discussion in mind, this study aims at connecting the portrayal of such a theme from novel to the two adaptations, also making use of a filmic analysis to identify techniques that highlight the depiction of the theme related to the three characters, ultimately linking such a thematic depiction to crises and social commotions that were taking place in both films' social contexts