2,890 research outputs found

    MirBot: A collaborative object recognition system for smartphones using convolutional neural networks

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    MirBot is a collaborative application for smartphones that allows users to perform object recognition. This app can be used to take a photograph of an object, select the region of interest and obtain the most likely class (dog, chair, etc.) by means of similarity search using features extracted from a convolutional neural network (CNN). The answers provided by the system can be validated by the user so as to improve the results for future queries. All the images are stored together with a series of metadata, thus enabling a multimodal incremental dataset labeled with synset identifiers from the WordNet ontology. This dataset grows continuously thanks to the users' feedback, and is publicly available for research. This work details the MirBot object recognition system, analyzes the statistics gathered after more than four years of usage, describes the image classification methodology, and performs an exhaustive evaluation using handcrafted features, convolutional neural codes and different transfer learning techniques. After comparing various models and transformation methods, the results show that the CNN features maintain the accuracy of MirBot constant over time, despite the increasing number of new classes. The app is freely available at the Apple and Google Play stores.Comment: Accepted in Neurocomputing, 201

    A Security Pattern for Cloud service certification

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    Cloud computing is interesting from the economic, operational and even energy consumption perspectives but it still raises concerns regarding the security, privacy, governance and compliance of the data and software services offered through it. However, the task of verifying security properties in services running on cloud is not trivial. We notice the provision and security of a cloud service is sensitive. Because of the potential interference between the features and behavior of all the inter-dependent services in all layers of the cloud stack (as well as dynamic changes in them). Besides current cloud models do not include support for trust-focused communication between layers. We present a mechanism to implement cloud service certification process based on the usage of Trusted Computing technology, by means of its Trusted Computing Platform (TPM) implementation of its architecture. Among many security security features it is a tamper proof resistance built in device and provides a root of trust to affix our certification mechanism. We present as a security pattern the approach for service certification based on the use TPM.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Genetic and Epigenetic Regulation in Nonalcoholic Fatty Liver Disease (NAFLD)

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    Genetics and epigenetics play a key role in the development of several diseases, including nonalcoholic fatty liver disease (NAFLD). Family studies demonstrate that first degree relatives of patients with NAFLD are at a much higher risk of the disease than the general population. The development of the Genome Wide Association Study (GWAS) technology has allowed the identification of numerous genetic polymorphisms involved in the evolution of diseases (e.g., PNPLA3, MBOAT7). On the other hand, epigenetic changes interact with inherited risk factors to determine an individual’s susceptibility to NAFLD. Modifications of the histones amino-terminal ends are key factors in the maintenance of chromatin structure and gene expression (cAMP-responsive element binding protein H (CREBH) or SIRT1). Activation of SIRT1 showed potential against the physiological mechanisms related to NAFLD. Abnormal DNA methylation represents a starting point for cancer development in NAFLD patients. Besides, the evaluation of circulating miRNA profiles represents a promising approach to assess and non-invasively monitor liver disease severity. To date, there is no approved pharmacologic therapy for NAFLD and the current treatment remains weight loss with lifestyle modification and exercise. In this review, the status of research into relevant genetic and epigenetic modifiers of NAFLD progression will be discusse

    Effects of discontinuities of the derivatives of the inflaton potential

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    We study the effects of a class of features of the inflaton potential, corresponding to discontinuties in its derivatives. We perform fully numerical calculations and derive analytical approximations for the curvature pertubations spectrum and the bispectrum which are in good agreement with the numerical results. The spectrum of primordial perturbations has oscillations around the scale k0k_0 which leaves the horizon at the time τ0\tau_0 when the feature occurs, with the amplitude and phase of the oscillations determined by the size and the order of the discontinuity. The large scale bispectrum in the squeezed and equilateral limits have a very similar form and are linearly suppressed. Both in the squeezed and equilateral small scale limit the bispectrum has an oscillatory behavior whose phase depends on the parameters determining the discontinuity, and whose amplitude is inversely proportional to the scale. Given the generality of this class of features they could be used to model or classify phenomenologically different types of non Gaussian features encountered in observational data such as the cosmic microwave background radiation or large scale structure.Comment: 26 pages, 22 figures, version accepted by EPJ

    CMB anomalies and the effects of local features of the inflaton potential

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    Recent analysis of the WMAP and Planck data have shown the presence of a dip and a bump in the spectrum of primordial perturbations at the scales k=0.002k=0.002 Mpc1{}^{-1} and k=0.0035k=0.0035 Mpc1{}^{-1} respectively. We analyze for the first time the effects a local feature in the inflaton potential to explain the observed deviations from scale invariance in the primordial spectrum. We perform a best fit analysis of the cosmic microwave background (CMB) radiation temperature and polarization data. The effects of the features can improve the agreement with observational data respect to the featureless model. The best fit local feature affects the primordial curvature spectrum mainly in the region of the bump, leaving the spectrum unaffected on other scales.Comment: 18 pages, 8figures, published in EPJ

    An operational framework for nonlocality

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    Due to the importance of entanglement for quantum information purposes, a framework has been developed for its characterization and quantification as a resource based on the following operational principle: entanglement among NN parties cannot be created by local operations and classical communication, even when N1N-1 parties collaborate. More recently, nonlocality has been identified as another resource, alternative to entanglement and necessary for device-independent quantum information protocols. We introduce an operational framework for nonlocality based on a similar principle: nonlocality among NN parties cannot be created by local operations and allowed classical communication even when N1N-1 parties collaborate. We then show that the standard definition of multipartite nonlocality, due to Svetlichny, is inconsistent with this operational approach: according to it, genuine tripartite nonlocality could be created by two collaborating parties. We finally discuss alternative definitions for which consistency is recovered

    Analysis of timber as sustainable material for construction

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    Comunicació presentada a IN-TECH 2014 International Conference on Innovative Technologies (Leiria, Portugal 10-13, september 2014).Facing the climate change scenario, professionals and technicians of civil engineering and architecture are searching for ecological solutions and construction methods that would allow for higher energy-efficiency and then reduce environmental impacts. Timber represents one of the best choices for energy-efficient construction, since it also functions as a material with good thermal transmittance properties if compared to other construction materials. This work analyses the possibilities and benefits that wood offers for the construction industry, in terms of sustainability. On the one hand, the sustainable forest management system contributes to ensure the quality and well-management in the exploitation of the forest in order to produce timber and other sub-products such as cork, paper and tree resins. In relation to this, the construction industry has an important role to increase the level of sustainable products by demanding certified timber. On the other hand, due to its Life Cycle Assessment (LCA), timber has the lower energy consumption compared to other building materials, as well as the CO2 stored and saved contributes to mitigate climate change. The LCA stages for the production of timber, the potential of saving carbon emissions and its comparison with other building products are presented. Concerning energy efficiency, once timber is implemented in a building taking part of the structure or as cladding material, it provides a high insulation decreasing the thermal transmittance of the walls, roofs, floors and windows. Its versatility as construction material also enables obtaining innovative solutions which can be implemented in buildings, as it is presented in this study. The optimum energy performance and low carbon emissions of timber make from this product a suitable and sustainable material to be highly considered for the construction industry
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