28 research outputs found

    Archetypal analysis: an alternative to clustering for unsupervised texture segmentation

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    Texture segmentation is one of the main tasks in image applications, specifically in remote sensing, where the objective is to segment high-resolution images of natural landscapes into different cover types. Often the focus is on the selection of discriminant textural features, and although these are really fundamental, there is another part of the process that is also influential, partitioning different homogeneous textures into groups. A methodology based on archetype analysis (AA) of the local textural measurements is proposed. AA seeks the purest textures in the image and it can find the borders between pure textures, as those regions composed of mixtures of several archetypes. The proposed procedure has been tested on a remote sensing image application with local granulometries, providing promising results

    A Data Science Analysis of Academic Staff Workload Profiles in Spanish Universities: Gender Gap Laid Bare

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    This paper presents a snapshot of the distribution of time that Spanish academic staff spend on different tasks. We carry out a statistical exploratory study by analyzing the responses provided in a survey of 703 Spanish academic staff in order to draw a clear picture of the current situation. This analysis considers many factors, including primarily gender, academic ranks, age, and academic disciplines. The tasks considered are divided into smaller activities, which allows us to discover hidden patterns. Tasks are not only restricted to the academic world, but also relate to domestic chores. We address this problem from a totally new perspective by using machine learning techniques, such as cluster analysis. In order to make important decisions, policymakers must know how academic staff spend their time, especially now that legal modifications are planned for the Spanish university environment. In terms of the time spent on quality of teaching and caring tasks, we expose huge gender gaps. Non-recognized overtime is very frequent

    Finding archetypal patterns for binary questionnaires

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    Archetypal analysis is an exploratory tool that explains a set of observations as mixtures of pure (extreme) patterns. If the patterns are actual observations of the sample, we refer to them as archetypoids. For the first time, we propose to use archetypoid analysis for binary observations. This tool can contribute to the understanding of a binary data set, as in the multivariate case. We illustrate the advantages of the proposed methodology in a simulation study and two applications, one exploring objects (rows) and the other exploring items (columns). One is related to determining student skill set profiles and the other to describing item response functions

    Analysis of Archetypes to Determine Time Use and Workload Profiles of Spanish University Professors

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    Allocation of time use is important to develop appropriate policies, especially in terms of gender equality. Individual well-being depends on many factors, including how time is spent. Therefore, knowing and analysing the time use and workload of academic staff is relevant for academic policy making. We analyse the responses of 703 Spanish academic staff regarding different activities of paid work and household work (unpaid). We use an innovative machine learning technique in this field, archetype analysis, which we introduce step by step while exploring our data. We identify five profiles, and we examine gender inequalities. The findings indicate that there is a higher prevalence of women in the profiles with a greater workload in household activities and teaching-related activities, but the prevalence is the same in the profile with a greater workload in research activities

    La educaci贸n en la encrucijada: miradas sociales y progresi贸n pedag贸gica en las puertas del 2020

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    Desde diferentes sectores sociales actualmente existe la tentaci贸n de exigir que la escuela sea el ant铆doto social por excelencia. Como consecuencia, las distintas reformas educativas tienden a adoptar decisiones que, a menudo, suelen desembocar en posicionamientos idealistas que no siempre tienen la capacidad de poder ayudar en la compleja tarea de reestructurar y mejorar la educaci贸n. En este contexto, la presente ponencia describe los medios que tiene a su alcance la pedagog铆a para escapar de la paradoja de la individualizaci贸n totalizante que conlleva el proceso de expansi贸n de las nuevas tecnolog铆as y, a la vez, reflexiona sobre la enga帽osa protecci贸n de la cerraz贸n en s铆 misma en la que la pedagog铆a ha ca铆do, en los 煤ltimos tiempos, como respuesta a la globalizaci贸n. Se llega a la conclusi贸n de que la concreci贸n de pautas, valores y pr谩cticas sobre las maneras mediante las que la existencia humana es capaz de mejorar su situaci贸n en el mundo requiere partir de premisas como: dotaciones presupuestarias adecuadas, fomento de la formaci贸n del profesorado y actualizaci贸n de metodolog铆as.Currently, from different social sectors there is the temptation to demand to the school to be the social antidote par excellence. Therefore, the different educational reforms tend to adopt decisions that often lead to idealistic positions that do not always have the capacity to help in the complex task of restructuring and improving education. In this context, the present paper describes the different possibilities that have the pedagogy to escape the paradox of totalizing individualization that involves the process of expansion of new technologies and, at the same time, reflects the tendency to close in itself, in which pedagogy has fallen as a response to globalization. It is concluded that the establishment of guidelines, values and practices on the ways in which human existence is able to improve their situation in the world requires starting from premises such as: adequate budget allocations, promotion of teacher training and updating methodologies

    Archetype analysis: A new subspace outlier detection approach

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    The problem of detecting outliers in multivariate data sets with continuous numerical features is addressed by a new method. This method combines projections into relevant subspaces by archetype analysis with a nearest neighbor algorithm, through an appropriate ensemble of the results. Our method is able to detect an anomaly in a simple data set with a linear correlation of two features, while other methods fail to recognize that anomaly. Our method performs among top in an extensive comparison with 23 state-of-the-art outlier detection algorithms with several benchmark data sets. Finally, a novel industrial data set is introduced, and an outlier analysis is carried out to improve the fit of footwear, since this kind of analysis has never been fully exploited in the anthropometric field.Funding for open access charge: CRUE-Universitat Jaume

    La gesti贸n del Big Data en la formaci贸n docente

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    Resumen: esta ponencia presenta el big data como una estructura conformadora de la acci贸n (docente) que va inevitablemente unida a la recolecci贸n de informaci贸n y gracias a la cual se planificar谩n los sistemas de referencia de las (futuras) pr谩cticas docentes. Aseveramos que el big data no excluye los intereses cl谩sicos de la pedagog铆a, m谩s bien los ensancha y los actualiza. Nos postulamos, en consecuencia, a favor de una concepci贸n de los datos como eje de desarrollo arm贸nico y en consonancia con la pedagog铆a. Esto implica la aceptaci贸n de la identificaci贸n de la informaci贸n individual de nuestro alumnado (que proviene del procesamiento de los datos) pero tambi茅n una aproximaci贸n intersubjetiva de la realidad

    La mejora en la escuela como eje de desarrollo social y como elemento al servicio de la tarea docente

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    Pon猫ncia presentada al V Congreso Internacional Virtual sobre Desarrollo Econ贸mico, Social y Empresarial en Iberoam茅rica, celebrat del 16 al 30 de junio de 2020, coordinat per la Universidad Aut贸noma Chapingo, M茅xicoPon猫ncia presentada al V Congreso Internacional Virtual sobre Desarrollo Econ贸mico, Social y Empresarial en Iberoam茅rica, celebrat del 16 al 30 de junio de 2020, coordinat per la Universidad Aut贸noma Chapingo, M茅xic

    Some contributions to archetypal analysis with applications

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    Aquesta Tesi desenvolupa l鈥橝n脿lisi d鈥橝rquetipus (AA) i demostra la seua viabilitat i rigor. Amplia la tipologia de dades amb les quals pot treballar utilitzant, a banda de les dades multivariants cont铆nues, dades bin脿ries i dades funcionals. Aquesta amalgama de dades l鈥檋em treballat implementant AA en diferents bases de dades, donant com a fruit tres investigacions independents. En la primera aportaci贸 treballem resultats d鈥檈x脿mens utilitzant una variant d鈥橝A, l鈥橝n脿lisi d鈥橝rquetipoids (ADA) amb dades bin脿ries i funcionals, en la segona aportaci贸 presentem un algorisme basat en AA per a treballar la segmentaci贸 de textures i en la darrera presentem un altre algorisme per a la cerca de dades at铆piques (outliers). En totes aquestes investigacions, s鈥檋an utilitzat dades reals i s鈥檋a fet un estudi comparatiu amb altres an脿lisis i algorismes m茅s reconeguts. Els resultats obtinguts han demostrat amb escreix la viabilitat i la compet猫ncia d鈥橝A.This Thesis develops the Archetype Analysis (AA) and demonstrates its viability and rigor. Expands the type of data which can work with, in addition to continuous multivariate data, it will manage binary data and functional data too. This amalgam of data will be used by implementing AA in different databases, resulting in three independent investigations. In the first contribution we work out exam results using a variant of AA, Archetypoids Analysis (ADA) with binary and functional data, in the second contribution we present an AA-based algorithm to work on texture segmentation and in the last one we present another algorithm for the search outliers. In all these investigations, real data have been used and a comparative study has been done with other more recognized analyzes and algorithms. The results obtained have demonstrated the AA feasibility and competence.Programa de Doctorat en Ci猫ncie
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