Spectral iterative algorithm for RCS computation in electrically large or intermediate perfectly conducting cavities

A novel algorithm designed to compute efficiently and accurately the high-frequency electromagnetic scattering from open-ended waveguide cavities is presented. The cavity is converted into a stepped-waveguide model so that the field spectra are propagated, forward and backward, along each waveguide section. As boundary conditions for perfect electric conductors are applied via image theory, they are of local nature and take into account only the first-order interactions between each pair of waveguide sections. Accordingly, additional forward-backward iterations must be performed if multiple interactions are to be taken into account. Finally, the radar cross section due to the interior irradiation is calculated by a Kirchhoff-based aperture integral. Good agreement with method of moments and hybrid modal solutions is found, as well as with experimental data, for two-dimensional and three-dimensional cavities with rectangular cross section.Peer Reviewe

A production planning model considering uncertain demand using two-stage stochastic programming in a fresh vegetable supply chain context

Production planning models are achieving more interest for being used in the primary sector of the economy. The proposed model relies on the formulation of a location model representing a set of farms susceptible of being selected by a grocery shop brand to supply local fresh products under seasonal contracts. The main aim is to minimize overall procurement costs and meet future demand. This kind of problem is rather common in fresh vegetable supply chains where producers are located in proximity either to processing plants or retailers. The proposed two-stage stochastic model determines which suppliers should be selected for production contracts to ensure high quality products and minimal time from farm-to-table. Moreover, Lagrangian relaxation and parallel computing algorithms are proposed to solve these instances efficiently in a reasonable computational time. The results obtained show computational gains from our algorithmic proposals in front of the usage of plain CPLEX solver. Furthermore, the results ensure the competitive advantages of using the proposed model by purchase managers in the fresh vegetables industry.This work was supported by the MEyC under contracts TIN2011-28689-C02-02, TRA2013-48180-C3-P and TIN2014- 53234-C2-2-R. The authors are members of the research group 2014-SGR163 and 2014-SGR151, funded by the Generali- tat de Catalunya

Infection by Strongyloides stercoralis in immigrants with Chagas disease: evaluation of eosinophilia as screening method in primary care

Objectives: to evaluate co-infection of Strongyloides stercoralis and Trypanosoma cruzi and to assess eosinophilia as a screening test for the detection of S. stercoralis infection in patients with Chagas disease (CD). Methods: a retrospective diagnostic validation study was performed on serum samples from primary care patients diagnosed with CD in the southern Barcelona metropolitan area. All samples with eosinophilia (n = 87) and a random sample of non-eosinophilic sera (n = 180) were selected. Diagnosis of CD was based on positive serology by means of two tests: ORTHO® T. cruzi ELISA test, and BIO-FLASH® Chagas or Bioelisa CHAGAS. SCIMEDX ELISA STRONGY-96 was used to diagnose strongyloidiasis. Results: strongyloides stercoralis serology was positive in 15% of patients of whom 95% showed eosinophilia, vs. 21% of those with negative serology (P < 0.001), with differences in the mean eosinophil count (0.49 vs. 0.27 × 109 /l). Only 1.1% of patients with CD but without eosinophilia presented positive serology for S. stercoralis, whereas 44% of patients with CD and eosinophilia did (P < 0.001). Sensitivity and specificity values for eosinophilia were thus 95% and 79%, respectively. PPV was 42.5% and NPV, 98.9%. Conclusions: the prevalence of co-infection by T. cruzi and S. stercoralis is not negligible and has probably been underestimated for years in many areas, due to frequently subclinical infections. Therefore, serology seems mandatory for these patients and the use of eosinophilia as initial screening could facilitate the task, decreasing the number of analyses to be performed

CISNE-P: a global scheduling oriented to now environments

In this work, we present an integral scheduling system for non-dedicated clusters, termed CISNE-P, which ensures the performance required by the local applications, while simultaneously allocating cluster resources to parallel jobs. Our approach solves the problem efficiently by using a social contract technique. This kind of technique is based on reserving computational resources, preserving a predetermined response time to local users. CISNE-P is a middleware which includes both a previously developed space-sharing job scheduler and a dynamic coscheduling system, a time sharing scheduling component. The experimentation performed in a Linux cluster shows that these two scheduler components are complementary and a good coordination improves global performance significantly. We also compare two different CISNE-P implementations: one developed inside the kernel, and the other entirely implemented in the user space.Facultad de Informátic

La situació de la família a Barcelona

El present document constitueix l'Informe sobre la Situació de la Família a la ciutat de Barcelona impulsat per l'Àmbit de Benestar Social de l'Ajuntament de Barcelona, amb motiu de l'Any Internacional de la Família i realitzat per l'Institut d'Estudis Metropolitans de Barcelona. L'Informe està concebut com a una síntesi interpretada de les dades disponibles més rellevants sobre les formes familiars i la situació de les famílies a la ciutat de Barcelona, relacionant bases de dades i fonts diverses i amb els objectius específics de: 1. Analitzar la situació actual de les formes familiars (dimensió i composició de les llars, aparició de noves estructures familiars diferents de les tradicionals, etc.) i característiques sòcio-econòmiques de les llars de Barcelona. 2. Aproximar-nos a les principals tendències d'evolució, amb especial referència als fenòmens emergents i a aquelles situacions susceptibles de ser objecte específic de les polítiques de benestar social, com ara el cas de les famílies unipersonals i monoparentals. L'estudi ha estat dirigit i redactat pels professors de la Universitat Autònoma de Barcelona, Lluís Flaquer del departament de Sociologia i Montse Solsona del departament de Geografia. La coordinació ha estat a càrrec de la sociòloga Lucía Baranda i la recerca i el tractament de la informació d'Elena Permanyer i Antoni Salvadó, tots ells membres de l'equip tècnic de l'Institut d'Estudis Metropolitans de Barcelon