8,845 research outputs found

    Test item taxonomy based of functional criteria

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    There are many taxonomies that try to classify and apply some consistency to the very many item types currently in existence. They all have various limitations, however, such as ambiguous classification criteria, little discrimination between format types, and referring almost exclusively to pen-and-paper or screen-based items. This paper aims to overcome these limitations by proposing a new item format taxonomy based on functional criteria. Current classifications are reviewed, the criteria they are based on are examined and their limitations are identified. The proposed alternative classification identifies four essential components of items according to function: the structure of the included content, the device used for transmission of the question to the examinee, the device for receiving the response, and the instructions to the examinee about how to understand and respond to the item. The combination of different facets of these four components allows any format of item to be classified, both existing formats and those that may appear in the future. In addition to systematically and coherently classifying items, this new taxonomy may also be of great utility in the construction and research of new items. The proposed model is illustrated by examples showing how specific items are classified, using a checklist as a guide.Ministerio de Economía y Competitividad de España PSI2014-56114-PMinisterio de Economía y Competitividad de España PSI2017-85724-

    Multi-­‐dimensional Protein Identification Technology

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    Before the rise of the Multidimentional Protein Identification Technology (MudPIT), protein and peptide mixtures were resolved using traditional proteomic technologies like the gel-­‐ based 2D chromatography that separates proteins by isoelectric point and molecular weight. This technique was tedious and limited, since the characterization of single proteins required isolation of protein gel spots, their subsequent proteolyzation and analysis using Matrix-­‐ assisted laser desorption/ionization-­‐time of flight (MALDI-­‐TOF) mass spectrometry

    The self organizing map of neighbour stars and its kinematical interpretation

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    The Self-Organizing Map (SOM) is a neural network algorithm that has the special property ofcreating spatially organized tepresetüatioes of various features of input signals. The resulting maps resemble realneural structures found in the cortices of developed animal brains.: Also, the SOM. has been successful in various pattern recognition tasks involving noisy signals, as for instance, speech recognition and for this reason we are studying its application to some astronomical problems. In this paper w~ present the 2-D mapping and subsequerít study of one local sample of 12000 stars using SOM. The available attributes are 14: 3-D position and velocitiesvphotometric indexes, spectral type and luminosity class. The possible location of halo, thick disk and thin disk stars is discussed. Their kinematical properties are also compared using the velocity distribution moments up to order four.Peer ReviewedPostprint (published version

    Variations in the efficiency of a mathematical programming solver according to the order of the constraints in the model

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    It is well-known that the efficiency of mixed integer linear mathematical programming depends on the model (formulation) used. With the same mathematical programming solver, a given problem can be solved in a brief calculation time using one model but requires a long calculation time using another. In this paper a new, unexpected feature to be taken into account is presented: the order of the constraints in the model can change the calculation time of the solver considerably. For a test problem, the Response Time Variability Problem (RTVP), it is shown that the ILOG CPLEX 9.0 optimizer returns a ratio of 17.47 between the maximum and the minimum calculations time necessary to solve optimally 20 instances of the RTVP, according to the order of the constraints in the model. It is shown that the efficiency of the mixed integer linear mathematical programming depends not only on the model (formulation) used, but also on how the information is introduced into the solverPeer Reviewe

    ¿Qué somos los psicólogos?: Una perspectiva metodológica sobre la cuestión «ciencia-tecnología» en Psicología

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    Con considerable frecuencia, el tema ciencia-tecnología aplicado a nuestra disciplina es planteado y debatido por los psicólogos, discutiéndose si nuestro trabajo debe ser propio de científicos o de técnicos, opinándose sobre si hay base para tal distinción y qué sentido podría tener, y enjuiciándose las razones por las que se debería considerar una y otra cosa. Además de estas discusiones, y muchas veces al margen de ellas, cada uno de los mismos psicólogos se sienten personalmente decantados hacia uno de los campos, sintiéndose además lejanos y diferentes unos de otros. Estas y otras cuestiones parecidas son abordadas en el presente artículo, tratando de mostrar cómo una perspectiva metodológica puede resultar conveniente para resituar ciertos aspectos del tema

    Formulaciones teóricas sobre la motivación de las actividades exploratorias: problemas y perspectivas

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    Se revisan en este trabajo las teorías elaboradas sobre la exploración, entendiéndolas como adaptaciones y extensiones a este campo de las propuestas a nivel de conductas en general. A partir del análisis de los logros y dificultades de cada una de ellas, se presentan las formulaciones incentivas de estado central como las más adecuadas para abordar el planteamiento de una alternativa teórica sobre la exploración, de la que exponen los principios básicos.This study reviews the theories that have been developed concerning exploration, dealing with them as adaptatons and extensions of those developed in the field of behavior in general. Starting with an analysis of the strengths and weaknesses of each of these theories, this study presents the central-state incentive formulations as the most appropiate in attempting to ouline a theoric alternative concerning explorations, and exposes its basic principles

    Geografia emocional d'un exode: La retirada republicana de 1939

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    This thesis proposes to trace and explore an emotional geography and cartography of the republican withdrawal at the end of the Spanish Civil War in Catalonia during the months of January and February 1939. Thus, it complements existing historiographical scholarship on the Spanish Civil War and Spanish Republican Exile, especially with regard to what was experienced in Catalan territory. However, its main purpose is not that of the historian, to reveal and explain unexplored stories, but to locate existing narratives, memoirs, journals and testimonies carefully in the landscape in which they took place, exposing their emotional bonds with the places and spaces of the withdrawal of the protagonists of the Republican exodus of 1939. Whilst there has been significant work in recent years to “recover” spaces associated with violent of traumatic memories of conflict and displacement, including the creation of a network of “Democratic Memory” places in Catalonia, the spaces explored in this thesis have not so far been construed as places of memory. In part, this is because of the diversity of emotions and affective responses they provoked and continue to evoke, but also because the geography of the Retirada is characterized by mobility and multiplicity. So instead of an historical approach, despite being influenced by Walter Benjamin's concept of history, this thesis draws on existing methods and approaches related to cultural geography, in particular, the emerging interdisciplinary field known as emotional geographies. In order to create a vision of La Retirada that is sensitive to its mobility and multiplicity, the primary methodology used has been that of interdisciplinary assemblage, juxtaposing images, documents and stories of past and present, in a process redolent of that which Marianne Hirsch calls "post-memory"
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