690 research outputs found

    Robust Visual Localization of a UAV over a Pipe-Rack Based on the Lie Group SE(3)

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    Visual inspection and maintenance ofindustrialpipes using robots represent an emerging application in Oil Gas and refinery facilities. In this domain, we present a pose tracking system based on a single camera sensor to localize an unmanned aerial vehicle operating over a pipe-rack to carry out inspection activities. We propose a unified framework based on the Lie group SE(3) which allows the simultaneous estimation of the pose of the UAV along with some parameters of the pipe-rack model. Numerical simulations have been performed to demonstrate the effectiveness of the proposed approach

    Brócoli envasado en polietileno de baja densidad y policloruro de vinilo

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    p.191-198La atmósfera modificada con películas plásticas y el control de la temperatura son tecnologías recomendadas para mantener la calidad y extender la vida de almacenamiento de hortalizas. Larespiración natural en brócoli envasado es suficiente para lograr niveles de dióxido de carbono (C 02) y de oxígeno (0 2) en el interior del envase que permitan alargar la vida del producto. Se realizaron tres ensayos a 0ºC, 8ºC y 12ºC en un diseño en parcela dividida con arreglo factorial. Se utilizaron dos películas plásticas: policloruro de vinilo y polietileno de baja densidad, y 4 diseños de paquete: 50, 100, 150 y 200 gramos de brócoli. Se midió la concentración de C 00 y 0 2 del interior de cada envase durante 7 días. Los cambios en la calidad se evaluaron por la pérdida de peso, el color y contenidos de ácido málico y de sólidos solubles durante el período analizado. La selección de la película óptima para el envasado de brócoli depende de la temperatura de almacenamiento y del peso del producto. A 0ºC, con PBD se logra una atmósfera adecuada con muy poca pérdida de peso y cambios químicos. A 8ºC, dado que no hay una variación importante de la calidad, la selección deberá realizarse por la concentración interna del gas lograda en el equilibrio y por la pérdida de peso durante el almacenamiento; así, es conveniente optar por PBD con una masa inferior a 100 gramos para obtener concentraciones óptimas de C 0 2 y de O, y por PVC cuando la masa es superior a 150 gramos para mantener baja la pérdida de peso. A 12ºC ninguna de las dos películas fueron buenas para el envasado de brócoli, porque generan la excesiva perdida de color y de peso (PVC) o la presencia de olores desagradables (PBD)

    Under the Knife: Non-Medical Childhood Genital Surgeries as a Form of Sexual Assault

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    Non-medical childhood genital surgeries, including cosmetic intersex surgeries, circumcisions, and female genital mutilations (FGM), have sparked ethical debates and human rights concerns for decades. This paper expands upon the existing discourse by arguing that these surgeries should be considered a form of sexual assault. First, sexual assault and acts of a sexual nature are defined, both of which are traditionally understood to include an objective and subjective component. Subsequently, each surgery is discussed within this framework, explaining how both components are fulfilled. The objective component is fulfilled by highlighting the violation of sexual freedom, the removal of genital tissue without consent, and the lasting damage inflicted upon healthy genitalia. As the surgeries fulfill the objective component, the child’s right to an open future is violated, along with their bodily integrity and the capacity to make autonomous decisions regarding their genital autonomy. Next, the paper explains the subjective component, which is traditionally linked to sexual intent. Because discerning intent can be complex for a variety of factors, the paper advocates for a revision of the way we understand the subjective component. A broader interpretation, influenced by social/cultural norms and historical context, allows these surgeries to sufficiently fulfill the subjective component. History, motives, and expectations underlying these surgeries include the preservation of potential heterosexual relations, the systematic oppression of women, and conformity to heteronormative gender norms. Mentioning the potential emotional and psychological impact felt by victims of these surgeries further supports the expanded understanding of subjectivity. While overt sexual intent may not always be present, the surgeries are linked to sexualized societal expectations and heteronormative ideals. The discussion of latent sexual implications and objective links to the violation of sexual freedom urges all to consider non-medical childhood genital surgeries as a form of sexual assault, an egregious wrong that should be tolerated by no culture or society. Considering these procedures to be sexual assault makes it apparent that society and medicine should shift priorities towards protecting bodily autonomy over heteronormative ideals

    Two semi-Lagrangian fast methods for Hamilton-Jacobi-Bellman equations

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    In this paper we apply the Fast Iterative Method (FIM) for solving general Hamilton-Jacobi-Bellman (HJB) equations and we compare the results with an accelerated version of the Fast Sweeping Method (FSM). We find that FIM can be indeed used to solve HJB equations with no relevant modifications with respect to the original algorithm proposed for the eikonal equation, and that it overcomes FSM in many cases. Observing the evolution of the active list of nodes for FIM, we recover another numerical validation of the arguments recently discussed in [Cacace et al., SISC 36 (2014), A570-A587] about the impossibility of creating local single-pass methods for HJB equations

    Visual control through narrow passages for an omnidirectional wheeled robot

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    Robotic systems are gradually replacing human intervention in dangerous facilities to improve human safety and prevent risky situations. In this domain, our work addresses the problem of autonomous crossing narrow passages in a semi-structured (i.e., partially-known) environment. In particular, we focus on the CERN’s Super Proton Synchrotron particle accelerator, where a mobile robot platform is equipped with a lightweight arm to perform measurements, inspection, and maintenance operations. The proposed approach leverages an image-based visual servoing strategy that exploits computer vision to detect and track known geometries defining narrow passage gates. The effectiveness of the proposed approach has been demonstrated in a realistic mock-up

    Nematic liquid crystal reorientation around multi-walled carbon nanotubes mapped via Raman microscopy

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    We have studied the formation of topological defects in liquid crystal (LC) matrices induced by multiwalled carbon nanotubes (MWCNTs) and external electric fields. The defects are ascribable to a distortion of the LC molecular director in proximity of the MWCNT surface. The system is analyzed macroscopically using spectroscopic variable angle ellipsometry. Concurrently, confocal micro-Raman spectroscopy is used to study the system state at the microscale. This allows to acquire a three-dimensional, spatially-resolved map of the topological defect, determining scale length variations and orientation topography of the LC molecules around the MWCNT

    MAP17 and SGLT1 Protein Expression Levels as Prognostic Markers for Cervical Tumor Patient Survival

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    MAP17 is a membrane-associated protein that is overexpressed in human tumors. Because the expression of MAP17 increases reactive oxygen species (ROS) generation through SGLT1 in cancer cells, in the present work, we investigated whether MAP17 and/or SGLT1 might be markers for the activity of treatments involving oxidative stress, such as cisplatin or radiotherapy. First, we confirmed transcriptional alterations in genes involved in the oxidative stress induced by MAP17 expression in HeLa cervical tumor cells and found that Hela cells expressing MAP17 were more sensitive to therapies that induce ROS than were parental cells. Furthermore, MAP17 increased glucose uptake through SGLT receptors. We then analyzed MAP17 and SGLT1 expression levels in cervical tumors treated with cisplatin plus radiotherapy and correlated the expression levels with patient survival. MAP17 and SGLT1 were expressed in approximately 70% and 50% of cervical tumors of different types, respectively, but they were not expressed in adenoma tumors. Furthermore, there was a significant correlation between MAP17 and SGLT1 expression levels. High levels of either MAP17 or SGLT1 correlated with improved patient survival after treatment. However, the patients with high levels of both MAP17 and SGLT1 survived through the end of this study. Therefore, the combination of high MAP17 and SGLT1 levels is a marker for good prognosis in patients with cervical tumors after cisplatin plus radiotherapy treatment. These results also suggest that the use of MAP17 and SGLT1 markers may identify patients who are likely to exhibit a better response to treatments that boost oxidative stress in other cancer types. © 2013 Perez et al.This work was supported by grants from the Spanish Ministry of Science and Innovation and FEDER funds (SAF2009-08605), Consejeria de Ciencia e Innovacion and Consejeria de Salud of the Junta de Andalucia (CTS-6844 and PI-0142) and FIS (PI12/00137). AC’s laboratory is also funded by a fellowship from the Fundacion Oncologica FERO, supported by Fundació Josep Botet.Peer Reviewe
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