702 research outputs found

    Support Vector Motion Clustering

    Get PDF
    This work was supported in part by the Erasmus Mundus Joint Doctorate in Interactive and Cognitive Environments (which is funded by the EACEA Agency of the European Commission under EMJD ICE FPA n 2010-0012) and by the Artemis JU and the UK Technology Strategy Board through COPCAMS Project under Grant 332913

    The 2020 IDS release of the Antwerp COR*-database. Evaluation, development and transformation of a pre-existing database

    Get PDF
    The Antwerp COR*-IDS database 2020 is a transformed and harmonized historical demographic database in a cross-nationally comparable format designed to be open and easy to use for international researchers. The database is constructed from the 2010 release of the Antwerp COR*-historical demographic database, which was created using a letter sample of the whole district of Antwerp (Flanders, Belgium). It has a total sample size of +/- 33,000 residents of Antwerp. The sample spans nearly seven decades. The data is collected from historical records: including population registers and vital registration records covering births, marriages, in/external migrations and deaths. The database covers up to three linked generations (in some cases more), and contains micro-data on individual level life courses, and relationships deriving from addressbased household composition methods. An important characteristic is the sample's large migrant population, including the timings of their demographic events and living arrangements, whilst resident in the district of Antwerp. In addition, the sample also contains a large array of occupational level information. This paper presents the processes, methodologies and documentation regarding the evaluation and development of a pre-existing historical database. This includes the systematic evaluation of the original samples, methodologies for address based reconstructing of households, and the geocoding of a historical database which took place during the current development of this new version of the database.info:eu-repo/semantics/publishedVersio

    Chasma Boreale, Mars: A Sapping and Outflow Channel with a Tectono-thermal Origin

    Get PDF
    A detailed geomorphological study of Chasma Boreale, a widely known feature of Mars’ north polar cap, has been carried out for the first time, along with a quantitative paleohydro logical model. It is concluded that the chasma was eroded by a flow whose discharge was on the order of magnitude of 109 m sec21. This catastrophic flow is thought to have been preceded by a powerful sapping process, caused by a tectonic control in the distribution and present aspect of most of the polar troughs. This tectonic forcing probably played a major role in the inception of not only Chasma Boreale but also other polar reentrants as wel

    Parabolic trough collectors. Fundamentals of heat transfer applied to solar thermal energy.

    Get PDF
    Solar thermal energy has undergone major development in recent years. The most widely used technologies are central receiver solar towers and parabolic trough collectors (PTC)[1]. The latter technology has great advantages due to its higher optical and thermal efficiency, but, despite being a well-proven technique, it presents certain problems inherent to the manufacturing and durability of some critical elements in the system. They are generally composed of an absorber tube surrounded by a glass cover and in the intermediate space, a vacuum is created to minimize thermal losses by convection[2]. The absorber tube is located at the focal line of a parabolic mirror that concentrates sun’s rays. To predict the thermal behavior of this type of system, ray-tracing techniques are used to determine the thermal load and accurate correlations are also needed to calculate the convective heat transfer. Also, the original design shows some problems such as the selective coating applied on the absorber surface, whose thermal performance decays with time. Besides, the metal-glass welding are also a significant weak spot, which due to the thermal expansion can cause the partial or total loss of the vacuum in the aforementioned annulus. In this work we present the results of the modeling of this type of systems in different working configurations, as well as a new design proposal to improve the thermal transfer in this type of systems.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Fomento del aprendizaje autónomo en una asignatura de computadores paralelos

    Get PDF
    Este trabajo presenta una actividad diseñada para una asignatura de arquitectura de computadores que estudia computadores paralelos. Se propuso para fomentar que los alumnos trabajen la asignatura durante todo el cuatrimestre, facilitar el estudio de los contenidos de la asignatura, mejorar la opinión de los alumnos sobre estos contenidos y favorecer el aprendizaje autónomo y una actitud reflexiva. La actividad consiste en un trabajo sobre un computador paralelo concreto y en uso. Los alumnos tienen que aplicar los contenidos de la asignatura al computador paralelo buscando información sobre éste en publicaciones especializadas y en páginas web y documentación de fabricantes y vendedores. La actividad se ha evaluado mediante una encuesta de opinión. Los resultados de ésta reflejan que contribuye a alcanzar los objetivos esperados

    Active Sampling-based Binary Verification of Dynamical Systems

    Full text link
    Nonlinear, adaptive, or otherwise complex control techniques are increasingly relied upon to ensure the safety of systems operating in uncertain environments. However, the nonlinearity of the resulting closed-loop system complicates verification that the system does in fact satisfy those requirements at all possible operating conditions. While analytical proof-based techniques and finite abstractions can be used to provably verify the closed-loop system's response at different operating conditions, they often produce conservative approximations due to restrictive assumptions and are difficult to construct in many applications. In contrast, popular statistical verification techniques relax the restrictions and instead rely upon simulations to construct statistical or probabilistic guarantees. This work presents a data-driven statistical verification procedure that instead constructs statistical learning models from simulated training data to separate the set of possible perturbations into "safe" and "unsafe" subsets. Binary evaluations of closed-loop system requirement satisfaction at various realizations of the uncertainties are obtained through temporal logic robustness metrics, which are then used to construct predictive models of requirement satisfaction over the full set of possible uncertainties. As the accuracy of these predictive statistical models is inherently coupled to the quality of the training data, an active learning algorithm selects additional sample points in order to maximize the expected change in the data-driven model and thus, indirectly, minimize the prediction error. Various case studies demonstrate the closed-loop verification procedure and highlight improvements in prediction error over both existing analytical and statistical verification techniques.Comment: 23 page

    El origen glaciar de la aureola del volcán Arsia Mons, Marte

    Get PDF
    Huge lobate deposits called aureoles are covering the base of the giant Martian volcanic constructs of Tharsis dome. The origin of these structures has been a matter of debate between two competing hypotheses: volcanic landslides or mountain glaciers. Here we consider the most important of the aureoles, near Arsia Mons, concluding that the glacier model explains best the deposit features, such as the layering, the ridges (interpreted as glaciotectonic ones), and the lobated terrain. We then discuss the fit of these proposed glacier deposits in the present paleoclimatic Martian models. The aureoles could be key elements in the confirmation of the «Baker cycle» model of repeated episodes of temperate, humid, sea-dominated climates coincident in time with the outflow channels activity.Al pie de los grandes volcanes marcianos del domo de Tharsis aparecen unas formas lobuladas que han recibido el nombre de aureolas. El origen de estas estructuras ha sido objeto de un largo debate entre dos hipótesis principales que las interpretan como deslizamientos de ladera o como glaciares de montaña. En este trabajo se estudia la mejor desarrollada de estas aureolas, la de Arsia Mons, llegándose a la conclusión de que la hipótesis glaciar explica mejor las características del depósito, y en concreto la existencia de estratificación, las crestas (que se interpretan como glaciotectónicas) y los terrenos lobulados. Por último se discute la conexión de estos depósitos con los modelos paleoclimáticos actuales sobre Marte, lo que lleva a la conclusión de que las aureolas deben ser depósitos glaciares recientes relacionados con repetidos episodios de clima cálido (ciclos de Baker), provocados por la acción de los canales de desbordamiento

    The ALMA Frontier Fields Survey - IV. Lensing-corrected 1.1 mm number counts in Abell 2744, MACSJ0416.1-2403 and MACSJ1149.5+2223

    Get PDF
    [abridged] Characterizing the number counts of faint, dusty star-forming galaxies is currently a challenge even for deep, high-resolution observations in the FIR-to-mm regime. They are predicted to account for approximately half of the total extragalactic background light at those wavelengths. Searching for dusty star-forming galaxies behind massive galaxy clusters benefits from strong lensing, enhancing their measured emission while increasing spatial resolution. Derived number counts depend, however, on mass reconstruction models that properly constrain these clusters. We estimate the 1.1 mm number counts along the line of sight of three galaxy clusters, i.e. Abell 2744, MACSJ0416.1-2403 and MACSJ1149.5+2223, which are part of the ALMA Frontier Fields Survey. We perform detailed simulations to correct these counts for lensing effects. We use several publicly available lensing models for the galaxy clusters to derive the intrinsic flux densities of our sources. We perform Monte Carlo simulations of the number counts for a detailed treatment of the uncertainties in the magnifications and adopted source redshifts. We find an overall agreement among the number counts derived for the different lens models, despite their systematic variations regarding source magnifications and effective areas. Our number counts span ~2.5 dex in demagnified flux density, from several mJy down to tens of uJy. Our number counts are consistent with recent estimates from deep ALMA observations at a 3σ\sigma level. Below \approx 0.1 mJy, however, our cumulative counts are lower by \approx 1 dex, suggesting a flattening in the number counts. In our deepest ALMA mosaic, we estimate number counts for intrinsic flux densities \approx 4 times fainter than the rms level. This highlights the potential of probing the sub-10 uJy population in larger samples of galaxy cluster fields with deeper ALMA observations.Comment: 19 pages, 14 figures, 3 tables. Accepted for publication in A&
    corecore