A discrete approach to Wirtinger's inequality

Considering Wirtinger's inequality for piece-wise equipartite functions we find a discrete version of this classical inequality. The main tool we use is the theorem of classification of isometries. Our approach provides a new elementary proof of Wirtinger's inequality that also allows to study the case of equality. Moreover it leads in a natural way to the Fourier series development of $2\pi$-periodic functions.Comment: 9 page

EL PROFESORADO DE LA FAREM-CARAZO ELABORA SU CARPETA DOCENTE

Este año se ha iniciado con el proyecto “Seguimiento y Evaluación de la mejora de la Calidad Docente (2012-2016)”, a través de la cooperación entre la Universidad Autónoma de Barcelona (UAB) y la Facultad Regional Multidisciplinaria de Carazo de UNAN-Managua. Su desarrollo persigue la mejora de la calidad educativa, mediante la reflexión y provocación al cambio de la labor docente. Se optó por realizar un estudio de caso en la FAREM-Carazo, con la finalidad de que se pueda tomar como ejemplo a desarrollar en el resto de facultades. Para ello, se cuenta con un equipo interdisciplinar e interfacultativo de la UAB con interés y experiencia en la innovación docente y con la participación de todo el profesorado de la facultad coordinado por la Msc. Juana del Socorro Rodríguez Lara, delegada por la FAREM-Carazo. A partir de enero del año 2016, se desarrolla el primer taller “Carpeta Docente” dirigido a 62 docentes de Planta de los departamentos de Ciencias de la Educación y Humanidades, Ciencias Económicas y Administrativas y Ciencia Tecnología y Salud. El objetivo del taller está relacionado con el dominio y elaboración de la carpeta docente como instrumento de reflexión y mejora, potenciar competencias en su quehacer docente y elaborar su carpeta docente en periodos establecidos. A inicios de agosto se desarrolló un segundo taller sobre el “Seguimiento y evaluación de la Carpeta Docente”, en el que se permitió comprobar el avance cualitativo y cuantitativo de la misma así como la reflexión de su quehacer como docente y las necesidades de formación del profesorado universitario, culminando con la entrega y presentación de las carpetas docentes. El resultado fue muy positivo y se proseguirá con la formación de asistencia voluntaria de los profesores horarios

Lesiones traumáticas en cráneos aislados de los poblados ibéricos de Ullastret (Girona)

X Congreso Nacional de Paleopatología. Univesidad Autónoma de Madrid, septiembre de 200

Anàlisi de la intrusió marina derivada de l’extracció d’aigua per a l’abastament urbà a Ciutadella (Menorca, Illes Balears, Mediterrània Occidental)

The Hydrogeological Unit Migjorn is composed of an Upper Miocene carbonate platform and represents the main water resource in the island of Menorca. This unit is affected by general seawater intrusion process preferably in the west. This study, integrating techniques of Electrical Resistivity Tomography (ERT) with hydrochemical data analysis from wells of urban water supply and correlation of borehole logs of these wells, allows new contributions to the knowledge of the hydrogeological problem in the town of Ciutadella de Menorca. Analysis of hydrochemical facies and its temporal evolution indicate all samples show chloride facies without exception, but with a very different distribution of chloride ion concentrations. This distribution is justified by the presence of collapse structures and karstifications detected by Electrical Resistivity Tomography, as well as textural variability of materials where the pumping occur

Three-dimensional finite element modelling of stack pollutant emissions

In this paper we propose a finite element method approach formodelling the air quality in a local scale over complex terrain. The area of interest is up to tens of kilometres and it includes pollutant sources. The proposed methodology involves the generation of an adaptive tetrahedral mesh, the computation of an ambient wind field, the inclusion of the plume rise effect in the wind field, and the simulation of transport and reaction of pollutants. The methodology is used to simulate a fictitious pollution episode in La Palma island (Canary Island, Spain).Peer ReviewedPostprint (published version

Interstitial pulmonary fibrosis with and without associated collagen vascular diseases: results of a two year follow up

Background: Interstitial pulmonary fibrosis is a disease with a highly variable clinical course. To ascertain if an inadequate selection of patients might explain part of this variability, two different groups of patients with interstitial pulmonary fibrosis, those with the 'lone' form of the disease (LIPF) and those with associated collagen vascular disorders (AIPF), were studied separately. Methods: Twenty consecutive patients (nine with LIPF and 11 with AIPF) were included. Their clinical and radiographic findings and results of pulmonary function tests, gallium-67 lung scanning, and cellular analysis of bronchoalveolar lavage fluid were compared at diagnosis. Moreover, the evolution of LIPF and AIPF was contrasted after a follow up of two years, both groups having received a similar treatment regimen of corticosteroids. Results: At enrollment, patients with LIPF and AIPF were of similar age, and had similar symptoms and derangement of lung function, but patients with LIPF presented with finger clubbing, more obvious radiographic abnormalities, and a greater percentage of eosinophils in bronchoalveolar lavage fluid. Two years later, patients with LIPF had significantly decreased FVC, FEV1, TLC, TLCO, and PaO2. By contrast, lung function remained unaltered in patients with AIPF. Similarly, when the percentage change from entry to the study was compared, patients with LIPF showed a significant decrease in FVC, FEV1, and PaO2. Conclusions: Unlike the patients with AIPF, those with LIPF showed a deterioration in lung function and developed further restrictive impairment and poorer gas exchange. This has implications in their clinical management

Numerical differentiation for non-trivial consistent tangent matrices: an application to the MRS-lade model

In a companion paper Pérez-Foguet, A., Rodríguez-Ferran, A. and Huerta, A. Numerical differentiation for local and global tangent operators in computational plasticity. Computer Methods in Applied Mechanics and Engineering, 2000, in press, the authors have shown that numerical differentiation is a competitive alternative to analytical derivatives for the computation of consistent tangent matrices. Relatively simple models were treated in that reference. The approach is extended here to a complex model: the MRS-Lade model. This plastic model has a cone-cap yield surface and exhibits strong coupling between the flow vector and the hardening moduli. Because of this, differentiating these quantities with respect to stresses and internal variables - the crucial step in obtaining consistent tangent matrices - is rather involved. Numerical differentiation is used here to approximate these derivatives. The approximated derivatives are then used to (1) compute consistent tangent matrices (global problem) and (2) integrate the constitutive equation at each Gauss point (local problem) with the Newton-Raphson method. The choice of the stepsize (i.e. the perturbation in the approximation schemes), based on the concept of relative stepsize, poses no difficulties. In contrast to previous approaches for the MRS-Lade model, quadratic convergence is achieved, for both the local and the global problems. The computational efficiency (CPU time) and robustness of the proposed approach is illustrated by means of several numerical examples, where the major relevant topics are discussed in detail.Peer ReviewedPostprint (author’s final draft

Numerical differentiation for non-trivial consistent tangent matrices: an application to the MRS-lade model

In a companion paper Pérez-Foguet, A., Rodríguez-Ferran, A. and Huerta, A. Numerical differentiation for local and global tangent operators in computational plasticity. Computer Methods in Applied Mechanics and Engineering, 2000, in press, the authors have shown that numerical differentiation is a competitive alternative to analytical derivatives for the computation of consistent tangent matrices. Relatively simple models were treated in that reference. The approach is extended here to a complex model: the MRS-Lade model. This plastic model has a cone-cap yield surface and exhibits strong coupling between the flow vector and the hardening moduli. Because of this, differentiating these quantities with respect to stresses and internal variables - the crucial step in obtaining consistent tangent matrices - is rather involved. Numerical differentiation is used here to approximate these derivatives. The approximated derivatives are then used to (1) compute consistent tangent matrices (global problem) and (2) integrate the constitutive equation at each Gauss point (local problem) with the Newton-Raphson method. The choice of the stepsize (i.e. the perturbation in the approximation schemes), based on the concept of relative stepsize, poses no difficulties. In contrast to previous approaches for the MRS-Lade model, quadratic convergence is achieved, for both the local and the global problems. The computational efficiency (CPU time) and robustness of the proposed approach is illustrated by means of several numerical examples, where the major relevant topics are discussed in detail

Efficient and accurate approach for powder compaction problems

In this paper, a new approach for powder cold compaction simulations is presented. A density-dependent plastic model within the framework of finite strain multiplicative hyperelastoplasticity is used to describe the highly nonlinear material behaviour; the Coulomb dry friction model is used to capture friction effects at die-powder contact; and an Arbitrary Lagrangian–Eulerian (ALE) formulation is used to avoid the (usual) excessive distortion of Lagrangian meshes caused by large mass fluxes. Several representative examples, involving structured and unstructured meshes are simulated. The results obtained agree with the experimental data and other numerical results reported in the literature. It is shown that, contrary to other Lagrangian and adaptive h-remeshing approaches recently reported for this type of problems, the present approach verifies the mass conservation principle with very low relative errors (less than 1% in all ALE examples and exactly in the pure Lagrangian examples). Moreover, thanks to the use of an ALE formulation and in contrast with other simulations, the presented density distributions do not present spurious oscillations