245 research outputs found

    Late vacuum choice and slow roll approximation in gravitational particle production during reheating

    Full text link
    In the transition between inflation and reheating, the curvature scalar typically undergoes oscillations which have significant impact on the density of gravitationally produced particles. The commonly used adiabatic vacuum prescription for the extraction of produced particle spectra becomes a non-reliable definition of vacuum in the regimes for which this oscillatory behavior is important. In this work, we study particle production for a scalar field non-minimally coupled to gravity, taking into account the complete dynamics of spacetime during inflation and reheating. We derive an approximation for the solution to the mode equation during the slow-roll of the inflaton and analyze the importance of Ricci scalar oscillations in the resulting spectra. Additionally, we propose a prescription for the vacuum that allows to safely extrapolate the result to the present, given that the test field interacts only gravitationally. Lastly, we calculate the abundance of dark matter this mechanism yields and compare it to observations.Comment: 24 pages, 11 figure

    Education, medicine and architectural practices for the ‘transhumanist subject’ of the 21st century

    Get PDF
    This paper evaluates the parameters of what has been called ‘posthumanism’ or ‘transhumanism’ from the idea of the biographic subject of the 20th century. The human/transhuman subject of the 21st century is addressed from three of its essential axes: first, education, which is understood in a global and holistic sense that affects all the aspects of a person. It is also a perspective that gives access to the other two variables tackled in this paper: health and space. Secondly, medicine: through an analysis of the renaissance and increasing demand of the medical humanities and through cross –biographical and structural– and multidisciplinary (ethics, philosophy, history, arts, psychology, etc.) references, a model for reflection is proposed, facing the imminent perspectives of change that will soon reach the regulated training in the field of health sciences. And finally, space. Contemporary architecture is part of a liquid culture in which everything is constantly redesigned: from infrastructures, installations, new materials, interfaces, networks, etc., to the very data from which they are nourished. In their interscalarity, all of them have a major impact on our bodies and subjectivities, producing complex urban organisms, landscapes and anthropic territories that are constantly modifying the face of the planet and its precarious environmental, political and social balance. It is thus necessary to rethink the conditions of contemporary design processes so that citizens get openly, consciously and actively involved.This research has benefited from the University of Alicante Research Project GRE 16-05: Children and Youth Literature on the Internet (LIJ 2.0). Analysis of Applications and Reading Social Networks

    An empirical comparative evaluation of gestUI to include gesture-based interaction in user interfaces

    Full text link
    [EN] Currently there are tools that support the customisation of users' gestures. In general, the inclusion of new gestures implies writing new lines of code that strongly depend on the target platform where the system is run. In order to avoid this platform dependency, gestUI was proposed as a model-driven method that permits (i) the definition of custom touch-based gestures, and (ii) the inclusion of the gesture-based interaction in existing user interfaces on desktop computing platforms. The objective of this work is to compare gestUI (a MDD method to deal with gestures) versus a code-centric method to include gesture-based interaction in user interfaces. In order to perform the comparison, we analyse usability through effectiveness, efficiency and satisfaction. Satisfaction can be measured using the subjects' perceived ease of use, perceived usefulness and intention to use. The experiment was carried out by 21 subjects, who are computer science M.Sc. and Ph.D. students. We use a crossover design, where each subject applied both methods to perform the experiment. Subjects performed tasks related to custom gesture definition and modification of the source code of the user interface to include gesture-based interaction. The data was collected using questionnaires and analysed using non-parametric statistical tests. The results show that gestUI is more efficient and effective. Moreover, results conclude that gestUI is perceived as easier to use than the code-centric method. According to these results, gestUI is a promising method to define custom gestures and to include gesture-based interaction in existing user interfaces of desktop-computing software systems. (C) 2018 Elsevier B.V. All rights reserved.This work has been supported by Department of Computer Science of the Universidad de Cuenca and SENESCYT of Ecuador, and received financial support from the Generalitat Valenciana under "Project IDEO (PROMETEOII/2014/039)" and the Spanish Ministry of Science and Innovation through the "DataMe Project (TIN2016-80811-P)".Parra-González, LO.; España Cubillo, S.; Panach Navarrete, JI.; Pastor López, O. (2019). An empirical comparative evaluation of gestUI to include gesture-based interaction in user interfaces. Science of Computer Programming. 172:232-263. https://doi.org/10.1016/j.scico.2018.12.001S23226317

    An analysis of taxi ratio in urban area using GIS

    Get PDF
    Urban development has started a change led by various factors: human impact on climate change, ageing population that is nowadays significant, increase of its density in urban environments, and processes of globalization that are promoted by incessant incorporation of new technologies. The Smarts cities have become a guinea pig for experimentation with new technologies, applying them to the mobility, infrastructures, energy or information. A focus of the new urban development model revolves around technology, and service needs depend more on the fact of having or being able to access to the specific data than the own available technology itself. Innovations in big data, free access to open data and cloud computing will affect urban development patterns. It is necessary to give substance to all that production, storage, processing and management of the data sources available: sensors, location and positioning systems, cloud computing, open data and communication networks. We proposes to add value to the data of the sources mentioned above, applied to public transport custom, in a city around 600.000 residents, through the GIS analysis of mobility patterns. Location and real time tracking of vehicles provide information on their status. It allows for taking decisions quickly and efficiently, and so on, establishing for example, mobility patterns. True challenge is to detect and transmit key information extracted from a huge volume of data, in which the public, private and business data must be combined effectively to achieve a more integrated knowledge of citizen habits in urban environment.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    La Capacidad de análisis en la formaciónde los trabajadores sociales: diseño de una rúbrica de evaluación de la competencia

    Get PDF
    En este artículo se presenta un instrumento de evaluación (rúbrica) específico para la adquisición de la competencia de pensamiento analítico en la formación de Trabajo Social, aplicable a las materias de áreas diversas y cursos del Grado de Trabajo Social. Se describe el proceso metodológico y el enfoque colaborativo de su construcción, impulsada por el Grupo de Innovación Docente Trans@net: transdisciplinariedad y aprendizaje en Trabajo Social de la Universidad de Barcelona. Este proyecto ha permitido avanzar a los docentes en su conceptualización y reducir la disparidad de los criterios evaluativos utilizados inicialmente. Aunar una visibilidad común ante los estudiantes al compartir un mismo instrumento entre asignaturas coetáneas y cursos diferentes. Favorecer la transversalidad al aplicarse a materias de distintas áreas de conocimiento y definir unas condiciones provisionales de aplicabilidad como: la vinculación a actividades de aprendizaje que acompañen su adquisición, la aplicación en ejercicios centrados específicamente o de forma prominente en el desarrollo de esta competencia, la necesidad de trabajar previamente con los estudiantes la comprensión de la competencia, el instrumento y las relaciones existentes entre los ítems de la rúbrica y el contexto del contenido de la asignatura y del ejercicio propuesto

    EVALUACIÓN DEL DESEMPEÑO DE FILTRO ADAPTADO PARA RADIO COGNITIVA

    Get PDF
    Este proyecto evalúa el rendimiento en la localización de filtros emparejados para la detección del espectro en Radio Cognitiva. Para resolver el problema del modelo de detección espectral se aplican dos hipótesis Ho y H1, las cuales generaron la probabilidad de detección (PD) y la probabilidad de falsa alarma (PFA) sobre una señal para un radio de ruido determinado (SNR). Se muestra como los filtros adaptados mantienen el rendimiento y el cumplimiento de los requisitos establecidos por el IEEE 802.22 en los cambios en la PFA y la potencia del ruido

    Calculation of kinetic parameters βeff and Λ with modified open source Monte Carlo code OpenMC(TD)

    Get PDF
    This work presents the methodology used to expand the capabilities of the Monte Carlo code OpenMC for the calculation of reactor kinetic parameters: effective delayed neutron fraction βeff and neutron generation time Λ. The modified code, OpenMC(Time-Dependent) or OpenMC(TD), was then used to calculate the effective delayed neutron fraction by using the prompt method, while the neutron generation time was estimated using the pulsed method, fitting Λ to the decay of the neutron population. OpenMC(TD) is intended to serve as an alternative for the estimation of kinetic parameters when licensed codes are not available. The results obtained are compared to experimental data and MCNP calculated values for 18 benchmark configurations.Fil: Romero Barrientos, J.. Comision Chilena de Energia Nuclear; Chile. Universidad de Chile; ChileFil: Marquez Damian, Jose Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. European Spallation Source; SueciaFil: Molina, F.. Comision Chilena de Energia Nuclear; Chile. Universidad Andrés Bello; ChileFil: Zambra, M.. Comision Chilena de Energia Nuclear; Chile. Universidad Diego Portales; ChileFil: Aguilera, P.. Comision Chilena de Energia Nuclear; Chile. Universidad de Chile; ChileFil: López Usquiano, F.. Comision Chilena de Energia Nuclear; Chile. Universidad de Chile; ChileFil: Parra, B.. Instituto de Física Corpuscular; EspañaFil: Ruiz, A.. Comision Chilena de Energia Nuclear; Chile. Universidad de Chile; Chil

    Operational realization of quantum vacuum ambiguities

    Full text link
    We provide a reinterpretation of the quantum vacuum ambiguities that one encounters when studying particle creation phenomena due to an external and time-dependent agent. We propose a measurement-motivated understanding: Each way of measuring the number of created particles selects a particular vacuum. This point of view gives a clear and physical meaning to the time evolution of the number of particles produced by the agent as the counts in a specific detector and, at the same time relates commonly used quantization prescriptions to particular measurement setups.Comment: 6 pages, 3 figure

    Personas mayores: innovación y emprendimiento

    Get PDF
    In this work we start from the reality of our long-lived society, which, as it has been said for a long time, is a challenge for this 21st century, we value the consequences of the increase in life expectancy and analyze the parameters of what we understand to be a "New retirement" that requires new tools and new intervention strategies. With this base we propose a change in the processes of preparation for retirement, in the curricula of the educational programs and in the activities programmed for the development of active aging, in addition to betting on the work of the elderly people who want it and for the empowerment of entrepreneurship at the beginning of retirement.En este trabajo partimos de la realidad de nuestra sociedad longeva que, como se viene diciendo desde hace tiempo, supone un desafío para este siglo XXI, valoramos las consecuencias del aumento de la esperanza de vida y analizamos los parámetros de lo que entendemos que es una “nueva jubilación” que requiere nuevas herramientas y nuevas estrategias de intervención. Con esta base proponemos un cambio en los procesos de preparación para la jubilación, en los currículos de los programas educativos y en las actividades programadas para el desarrollo del envejecimiento activo, además de apostar por el trabajo de las personas mayores que lo deseen y por la potenciación del emprendimiento en los inicios de la jubilación

    New electrohysterogram-based estimators of intrauterine pressure signal, tonus and contraction peak for non-invasive labor monitoring

    Full text link
    [EN] Background: Uterine activity monitoring is an essential part of managing the progress of pregnancy and labor. Although intrauterine pressure (IUP) is the only reliable method of estimating uterine mechanical activity, it is highly invasive. Since there is a direct relationship between the electrical and mechanical activity of uterine cells, surface electrohysterography (EHG) has become a noninvasive monitoring alternative. The Teager energy (TE) operator of the EHG signal has been used for IUP continuous pressure estimation, although its accuracy could be improved. We aimed to develop new optimized IUP estimation models for clinical application. Approach: We first considered enhancing the optimal estimation of IUP clinical features (maximum pressure and tonus) rather than optimizing the signal only (continuous pressure). An adaptive algorithm was also developed to deal with inter-patient variability. For each optimizing signal feature (continuous pressure, maximum pressure and tonus), individual (single patient), global (full database) and adaptive models were built to estimate the recorded IUP signal. The results were evaluated by computing the root mean square errors (RMSe): continuous pressure error (CPe), maximum pressure error (MPe) and tonus error (TOe). Main results: The continuous pressure global model yielded IUP estimates with Cpe = 14.61mm Hg, MPe = 29.17mm Hg and Toe = 7.8mm Hg. The adaptive models significantly reduced errors to CPe = 11.88, MPe = 16.02 and Toe = 5.61mm Hg. The EHG-based IUP estimates outperformed those from traditional tocographic recordings, which had significantly higher errors (CPe = 21.93, MPe = 26.97, and TOe = 13.96). Significance: Our results show that adaptive models yield better IUP estimates than the traditional approaches and provide the best balance of the different errors computed for a better assessment of the labor progress and maternal and fetal wellbeing.This research project was supported by the Spanish Ministry of Economy and Competitiveness, the European Regional Development Fund (DPI2015-68397-R), and by the projects UPV_ FE-2018-C03 and GV/2018/104.Benalcazar-Parra, C.; Garcia-Casado, J.; Ye Lin, Y.; Alberola-Rubio, J.; López-Corral, A.; Perales Marin, AJ.; Prats-Boluda, G. (2019). New electrohysterogram-based estimators of intrauterine pressure signal, tonus and contraction peak for non-invasive labor monitoring. Physiological Measurement. 40(8):1-12. https://doi.org/10.1088/1361-6579/ab37dbS11240
    corecore