4,365 research outputs found

    Twenty-First-Century Challenges: The Use of Military Forces to Combat Criminal Threats

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    A Proposal for a Machine Learning Classifier for Viral Infection in Living Cells Based on Mitochondrial Distribution

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    The study of viral infections using live cell imaging (LCI) is an important area with multiple opportunities for new developments in computational cell biology. Here, this point is illustrated by the analysis of the sub-cellular distribution of mitochondrium in cell cultures infected by Dengue virus (DENV) and in uninfected cell cultures (Mock-infections). Several videos were recorded from the overnight experiments performed in a confocal microscopy of spinning disk. The density distribution of mitochondrium around the nuclei as a function of time and space ρ(r, θ, t) was numerically modeled as a smooth interpolation function from the image data and used in further analysis. A graphical study shows that the behavior of the mitochondrial density is substantially different when the infection is present. The DENV-infected cells show a more diffuse distribution and a stronger angular variation on it. This behavior can be quantified by using some usual image processing descriptors called entropy and uniformity. Interestingly, the marked difference found in the mitochondria density distribution for mock and for infected cell is present in every frame and not an evidence of time dependence was found, which indicate that from the start of the infections the cells are showing an altered subcellular pattern in mitochondrium distribution. Ulteriorly, it would be important to study by analysis of time series for clearing if there is some tendency or approximate cycles. Those findings are suggesting that using the image descriptors entropy and uniformity it is possible to create a machine learning classifier that could recognize if a single selected cell in a culture has been infected or not

    Integración, crisis y oportunidades: el caso andino.

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    Este documento ha considerado algunos de los aspectos más importantes del proceso de integración andina, pasando desde la descripción de los principales indicadores macroeconómicos hasta abordar temas como el proceso que han tenido a la fecha de hoy las reformas comerciales unilaterales; las alternativas de integración con el mundo y en la Comunidad Andina; y la agenda restante de reformas que a futuro se deben consolidar para alcanzar una mejor integración.

    Methodology for the metric restoration of the historical cartography applied to Francisco Coello's cartografic series of the Royal Site of Aranjuez

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    Hojas Kilométricas (Kilometric Sheets). Specifically, the study focuses on those sheets referring to the city centre and surrounding area of the Royal Site of Aranjuez, a town in the south of the Province of Madrid. The aim of this study is to restore the actual size and measurements of scanned images of the Hojas Kilométricas. This would allow us, among other things, to reestablish both the format and scale of the original plans. To achieve this goal it is necessary to rectify and then georeference these images, i.e. assign them a geographic reference system. This procedure is essential in the overlaying and comparison of the Hojas Kilométricas of the Royal Site with other historical cartography as well as other sources related to the same area from different time periods. Subsequent research would allow us, for example, to reconstruct the time-evolution of the urban area, to spot new construction and to pinpoint the locations of any altered or missing buildings or architectural features. In addition, this would allow us to develop and integrate databases for GIS models applicable to the management of our cultural heritage

    Contextual factors and contingent reward leadership: employer adoption of telecommuting

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    Using a contingency perspective, this paper examines the conditions under which telecommuting is most likely to be adopted with data obtained from a sample of 122 CEOs. We hypothesized that telecommuting fits better in younger organizations, firms with a higher proportion of women and international employees in workforce, and companies that offer variable pay. We found evidence that confirm the prediction that telecommuting, a high proportion of international employees, and the use of variable compensation as an internal control mechanism tend to go hand in hand.

    Kinematics of Big Biomedical Data to characterize temporal variability and seasonality of data repositories: Functional Data Analysis of data temporal evolution over non-parametric statistical manifolds

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    [EN] Aim: The increasing availability of Big Biomedical Data is leading to large research data samples collected over long periods of time. We propose the analysis of the kinematics of data probability distributions over time towards the characterization of data temporal variability. Methods: First, we propose a kinematic model based on the estimation of a continuous data temporal trajectory, using Functional Data Analysis over the embedding of a non-parametric statistical manifold which points represent data temporal batches, the Information Geometric Temporal (IGT) plot. This model allows measuring the velocity and acceleration of data changes. Next, we propose a coordinate-free method to characterize the oriented seasonality of data based on the parallelism of lagged velocity vectors of the data trajectory throughout the IGT space, the Auto-Parallelism of Velocity Vectors (APVV) and APVVmap. Finally, we automatically explain the maximum variance components of the IGT space coordinates by means of correlating data points with known temporal factors from the domain application. Materials: Methods are evaluated on the US National Hospital Discharge Survey open dataset, consisting of 3,25M hospital discharges between 2000 and 2010. Results: Seasonal and abrupt behaviours were present on the estimated multivariate and univariate data trajectories. The kinematic analysis revealed seasonal effects and punctual increments in data celerity, the latter mainly related to abrupt changes in coding. The APVV and APVVmap revealed oriented seasonal changes on data trajectories. For most variables, their distributions tended to change to the same direction at a 12-month period, with a peak of change of directionality at mid and end of the year. Diagnosis and Procedure codes also included a 9-month periodic component. Kinematics and APVV methods were able to detect seasonal effects on extreme temporal subgrouped data, such as in Procedure code, where Fourier and autocorrelation methods were not able to. The automated explanation of IGT space coordinates was consistent with the results provided by the kinematic and seasonal analysis. Coordinates received different meanings according to the trajectory trend, seasonality and abrupt changes. Discussion: Treating data as a particle moving over time through a multidimensional probabilistic space and studying the kinematics of its trajectory has turned out to a new temporal variability methodology. Its results on the NHDS were aligned with the dataset and population descriptions found in the literature, contributing with a novel temporal variability characterization. We have demonstrated that the APVV and APVVmat are an appropriate tool for the coordinate-free and oriented analysis of trajectories or complex multivariate signals. Conclusion: The proposed methods comprise an exploratory methodology for the characterization of data temporal variability, what may be useful for a reliable reuse of Big Biomedical Data repositories acquired over long periods of time.This work was supported by UPV grant No. PAID-00-17, and projects DPI2016-80054-R and H2020-SC1-2016-CNECT No. 727560.Sáez, C.; Garcia-Gomez, JM. (2018). Kinematics of Big Biomedical Data to characterize temporal variability and seasonality of data repositories: Functional Data Analysis of data temporal evolution over non-parametric statistical manifolds. International Journal of Medical Informatics. 119:109-124. https://doi.org/10.1016/j.ijmedinf.2018.09.015S10912411

    Management System for Harvest Scheduling: The Case of Horticultural Production in Southeast Spain

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    horticultural farmer, optimization, planning, mathematical programming, marketing, cooperative, Agribusiness, Crop Production/Industries, Demand and Price Analysis, Farm Management, Land Economics/Use,

    Propuesta de mejoramiento de los procesos productivos a traves de un estudio de tiempos y movimientos, para elevar la productividad de una empresa manufacturera de la Region del Maule

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    227 p.El presente estudio se concibió a partir del conocimiento del método de trabajo imperante en la planta de la empresa GeoMuebles Ltda., y en particular, del alto nivel existente de deserdicio de la mano de obra en ella, aseveración respaldada por datos suministrados con anterioridad. Se escogió la tecnica del estudio de tiempos y movimientos, puesto que es un metodo muy sistematico para diagnosticar, analizar y desarrollar metodos de trabajo, y especializarse enefectuar mejoras, con un minimo de inversion, en la empresa estudiada. El estudio comienza con una introduccion, donde se detallan los objetivos y la metodologia a utilizar. Luego, el marco teorico, otorga las bases con la que se sustenta el estudio de tiempos y movimientos, y en particular describe el aumento de la productividad, el que constituye uno de los principales objetivos de este estudio. A continuacion, se realiza una breve descripcion de la empresa, los principales productos elaborados, sus respectivas proyecciones y sus procesos productivos. Con la ayuda de tecnicas como el analisis de Pareto y el diagrama Causa-Efecto, se realiza un diagnostico de la situacion actual de la empresa, los cuales indican las principales causas de los problemasexistentes y que en su conjunto evidencian la ineficiencia de la empresa. Asimismo, se establecen indices de productividad para la empresa, los que permiten una medicion actual de la empresa y que en un futuro serviran para evaluar las mejoras realizadas. La parte central del estudio, es el desarrollo del estudio de tiempos y movimientos, el que comienza con la recopilacion de los datos del proceso productivo actual, formalizando los procesos productivos a traves del diagrama de flujo. Ademas, se confeccionan diagramas de proceso, con los elementos de trabajo que constituyen cada uno de los procesos productivos de las areas que componen la linea de tapizado; diagramas de recorrido, donde se determinaron datos de distancia de los traslados indicados en los diagramas de proceso, con el fin de examinar en forma critica la trayectoria que siguen los materiales y operarios, y observar la disposicion de la planta; y diagramas para el levantamiento de tiempos, con los que se determino los tiempos de proceso de las operaciones identificadas como elementos de trabajo. Como ultimo paso del estudio de tiempos, se procede a analizar los datos obtenidos mediante el cuestionario para el examen critico del metodo de trabajo, dando origen a los lineamientos que permitiran el rediseno de las operaciones existentes, y posteriormente, el desarrollo del metodo ideal, el que se registra mediante nuevos diagramas de proceso. Para finalizar, se realizan diversas propuestas de mejoras. La primera propuesta es la mejora del metodo de trabajo en la linea de tapizado de la empresa, logrando reducciones del 23,1% en el tiempo de proceso de corte de tela de modelos simples y del 20,0% en complejos; en el area de costura, cuyas reducciones equivalen al 22,4% y 21,3% en la confeccion de livings simples y complejos, respectivamente; en el area de trozado, las reducciones de tiempo son equivalentes al 29,2% en el trozado de modelos simples y 15,5% en modelos complejos. Luego se realiza una propuesta para mejorar el actual sistema de salarios de la empresa; se sugieren balances de la linea de tapizado, en funcion de la programacion mensual estimada y se termina con la propuesta de un nuevo layout de la empresa
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