10,339 research outputs found

    Optimal control of unilateral obstacle problem with a source term

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    We consider an optimal control problem for the obstacle problem with an elliptic variational inequality. The obstacle function which is the control function is assumed in H2H^{2}. We use an approximate technique to introduce a family of problems governed by variational equations. We prove optimal solutions existence and give necessary optimality conditions

    A Case of Recurrent Transient Monocular Visual Loss after Receiving Sildenafil

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    A 53-year-old man was attended to the Clinic Ophthalmic Center, Mansoura University, Egypt, with recurrent transient monocular visual loss after receiving sildenafil citrate (Viagra) for erectile dysfunction. Examination for possible risk factors revealed mild hypercholesterolemia. Family history showed that his father had suffered from bilateral nonarteritic anterior ischemic optic neuropathy (NAION). Physicians might look for arteriosclerotic risk factors and family history of NAION among predisposing risk factors before prescribing sildenafil erectile dysfunction drugs

    Therapeutic contact lenses and the advantages of high Dk materials

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    As lentes de contato terapêuticas são úteis para o tratamento de uma série de doenças da superfície ocular. Suas principais finalidades são: reduzir a dor; proteger a córnea; facilitar e manter a cicatrização epitelial; restaurar a câmara anterior e liberar medicamentos na superfície ocular. Há uma variedade de tipos e materiais, sendo que a escolha depende da doença a ser tratada, tempo de uso e necessidades fisiológicas do olho doente. Doenças como a ceratopatia bolhosa, erosão recorrente do epitélio corneano, olho seco e defeitos epiteliais pós-operatórios, além de várias outras doenças que afetam a superfície ocular podem ser tratadas com a utilização das lentes de contato terapêuticas. Elas não devem ser utilizadas em processos infecciosos ou em pacientes que estão impossibilitados de retornar para acompanhamento regular. A adaptação, controle e manutenção adequados das lentes de contato terapêuticas são fundamentais para prevenir complicações, como: neovascularização corneana, conjuntivite papilar gigante ou ceratite infecciosa. O controle e manutenção foram facilitados com o advento das lentes de contato terapêuticas de silicone-hidrogel. Essas lentes permitem trocas menos freqüentes devido a sua maior oxigenação e, em casos selecionados, aceleram a reepitelização corneana.Therapeutic contact lenses are useful in a variety of ocular surface diseases. Their main indications are: to relieve the pain; protect ocular surface; promote corneal healing and epithelial regeneration; seal a leaking corneal wound and deliver ophthalmic drugs on the ocular surface. There are several kinds of lens designs and materials, and their choice is dependent on the specific disease to be treated, the duration of treatment and the physiologic needs of the diseased cornea. Bullous keratopathy, recurrent epithelial erosion syndrome, dry eye and postoperative epithelial defects are amongst their indications. Therapeutic contact lenses should not be indicated in the presence of active infectious keratitis or when the patient is not compliant. Corneal neovascularization, giant papillary conjunctivitis and infectious keratitis are serious complications, which can be prevented by correctly fitting and maintaining the therapeutic contact lenses. Silicon-hydrogel therapeutic contact lenses, due to their higher oxygen permeability, allow extended wear schedules, decreasing the need for frequent lens replacement

    Providing a Gender Perspective to Integration in Western Europe. Muslim Women\u2019s Agency between Multicultural and Assimilationist Policies

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    While scholars have tried to assess the presumed increase of the civic integration approach and the failure of multiculturalism in Western Europe, little research has been conducted to uncover the ways in which these two understandings of integration could promote Muslim women\u2019s agency within their communities and in the broader national space. This analysis will address the possible implications of each model\u2019s integration policies targeting second and third generation Muslim women, taking into account the role played by religion to justify life choices with family and community members in the specific context of European Islam. A younger generation of Muslim women refers to religious identity and knowledge of \u2018Pure Islam\u2019 as resources to gain personal worth and respected roles within their communities. This article will first challenge the alleged backlash of Multiculturalism through a gender lens and then it will provide a framework of understanding of Muslim women\u2019s agency. To conclude, the article argues that multicultural policies rather than more assimilationist or universalist measures, could have a better impact on the promotion of Muslim women\u2019s agency. Measures such as those listed by the Multicultural Policy Index, developed by Keith Banting and Will Kymlicka at Queen\u2019s University, are more likely to provide women with the tools used to negotiate life choices and their presence in the public space

    Modeling Dynamic Swarms

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    This paper proposes the problem of modeling video sequences of dynamic swarms (DS). We define DS as a large layout of stochastically repetitive spatial configurations of dynamic objects (swarm elements) whose motions exhibit local spatiotemporal interdependency and stationarity, i.e., the motions are similar in any small spatiotemporal neighborhood. Examples of DS abound in nature, e.g., herds of animals and flocks of birds. To capture the local spatiotemporal properties of the DS, we present a probabilistic model that learns both the spatial layout of swarm elements and their joint dynamics that are modeled as linear transformations. To this end, a spatiotemporal neighborhood is associated with each swarm element, in which local stationarity is enforced both spatially and temporally. We assume that the prior on the swarm dynamics is distributed according to an MRF in both space and time. Embedding this model in a MAP framework, we iterate between learning the spatial layout of the swarm and its dynamics. We learn the swarm transformations using ICM, which iterates between estimating these transformations and updating their distribution in the spatiotemporal neighborhoods. We demonstrate the validity of our method by conducting experiments on real video sequences. Real sequences of birds, geese, robot swarms, and pedestrians evaluate the applicability of our model to real world data.Comment: 11 pages, 17 figures, conference paper, computer visio

    ISTA-Net: Interpretable Optimization-Inspired Deep Network for Image Compressive Sensing

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    With the aim of developing a fast yet accurate algorithm for compressive sensing (CS) reconstruction of natural images, we combine in this paper the merits of two existing categories of CS methods: the structure insights of traditional optimization-based methods and the speed of recent network-based ones. Specifically, we propose a novel structured deep network, dubbed ISTA-Net, which is inspired by the Iterative Shrinkage-Thresholding Algorithm (ISTA) for optimizing a general 1\ell_1 norm CS reconstruction model. To cast ISTA into deep network form, we develop an effective strategy to solve the proximal mapping associated with the sparsity-inducing regularizer using nonlinear transforms. All the parameters in ISTA-Net (\eg nonlinear transforms, shrinkage thresholds, step sizes, etc.) are learned end-to-end, rather than being hand-crafted. Moreover, considering that the residuals of natural images are more compressible, an enhanced version of ISTA-Net in the residual domain, dubbed {ISTA-Net}+^+, is derived to further improve CS reconstruction. Extensive CS experiments demonstrate that the proposed ISTA-Nets outperform existing state-of-the-art optimization-based and network-based CS methods by large margins, while maintaining fast computational speed. Our source codes are available: \textsl{http://jianzhang.tech/projects/ISTA-Net}.Comment: 10 pages, 6 figures, 4 Tables. To appear in CVPR 201
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