Landau Gauge Fixing on GPUs and String Tension

We explore the performance of CUDA in performing Landau gauge fixing in Lattice QCD, using the steepest descent method with Fourier acceleration. The code performance was tested in a Tesla C2070, Fermi architecture. We also present a study of the string tension at finite temperature in the confined phase. The string tension is extracted from the color averaged free energy and from the color singlet using Landau gauge fixing.Comment: 7 pages, 4 figures, 1 table. Contribution to the International Meeting "Excited QCD", Peniche, Portugal, 06 - 12 May 201

Landau gauge fixing on the lattice using GPU's

In this work, we consider the GPU implementation of the steepest descent method with Fourier acceleration for Laudau gauge fixing, using CUDA. The performance of the code in a Tesla C2070 GPU is compared with a parallel CPU implementation.Comment: 3 pages, 1 figure, Proceedings of the Xth Quark Confinement and the Hadron Spectrum, 8-12 October 2012, TUM Campus Garching, Munich, German

The lattice gluon propagator in renormalizable ξ\xi gauges

We study the SU(3) gluon propagator in renormalizable $R_\xi$ gauges implemented on a symmetric lattice with a total volume of (3.25 fm)$^4$ for values of the guage fixing parameter up to $\xi=0.5$. As expected, the longitudinal gluon dressing function stays constant at its tree-level value $\xi$. Similar to the Landau gauge, the transverse $R_\xi$ gauge gluon propagator saturates at a non-vanishing value in the deep infrared for all values of $\xi$ studied. We compare with very recent continuum studies and perform a simple analysis of the found saturation with a dynamically generated effective gluon mass.Comment: 6 pages, 4 figure

Intra-abdominal infections: the role of different classifications on the selection of the best antibiotic treatment

The study was approved by the local ethics committee, Departamento de Ensino, Formação e Investigação (DEFI) of Centro Hospitalar Universitário do Porto (CHUP) - ref. 2017.226(195-DEFI/187-CES). The need for consent was waived by the local ethics committee and patient data was de-identifiedBackground: Intra-abdominal infections (IAIs) represent a most frequent gastrointestinal emergency and serious cause of morbimortality. A full classification, including all facets of IAIs, does not exist. Two classifications are used to subdivide IAIs: uncomplicated or complicated, considering infection extent; and community-acquired, healthcare-associated or hospital-acquired, regarding the place of acquisition. Adequacy of initial empirical antibiotic therapy prescribed is an essential need. Inadequate antibiotic therapy is associated with treatment failure and increased mortality. This study was designed to determine accuracy of different classifications of IAIs to identify infections by pathogens sensitive to current treatment guidelines helping the selection of the best antibiotic therapy. Methods: A retrospective cohort study including all adult patients discharged from hospital with a diagnosis of IAI between 1st of January and 31st of October, 2016. All variables potentially associated with pre-defined outcomes: infection by a pathogen sensitive to non-pseudomonal cephalosporin or ciprofloxacin plus metronidazole (ATB 1, primary outcome), sensitive to piperacillin-tazobactam (ATB 2) and hospital mortality (secondary outcomes) were studied through logistic regression. Accuracy of the models was assessed by area under receiver operating characteristics (AUROC) curve and calibration was tested using the Hosmer-Lemeshow goodness-of-fit test. Results: Of 1804 patients screened 154 met inclusion criteria. Sensitivity to ATB 1 was independently associated with male gender (adjusted OR = 2.612) and previous invasive procedures in the last year (adjusted OR = 0.424) (AUROC curve = 0,65). Sensitivity to ATB 2 was independently associated with liver disease (adjusted OR = 3.580) and post-operative infections (adjusted OR = 2.944) (AUROC curve = 0.604). Hospital mortality was independently associated with age ≥ 70 (adjusted OR = 4.677), solid tumour (adjusted OR = 3.127) and sensitivity to non-pseudomonal cephalosporin or ciprofloxacin plus metronidazole (adjusted OR = 0.368). The accuracy of pre-existing classifications to identify infection by a pathogen sensitive to ATB 1 was 0.59 considering place of acquisition, 0.61 infection extent and 0.57 local of infection, for ATB 2 it was 0.66, 0.50 and 0.57, respectively. Conclusion: None of existing classifications had a good discriminating power to identify IAIs caused by pathogens sensitive to current antibiotic treatment recommendations. A new classification, including patients' individual characteristics like those included in the current model, might have a higher potential to distinguish IAIs by resistant pathogens allowing a better choice of empiric antibiotic therapy.info:eu-repo/semantics/publishedVersio

On computing real logarithms for matrices in the Lie group of special Euclidean motions in Rn

We show that the diagonal Pade approximants methods, both for computing the principal logarithm of matrices belonging to the Lie groupSE (n, IR) of special Euclidean motions in IRn and to compute the matrix exponential of elements in the corresponding Lie algebra se(n, IR), are structure preserving. Also, for the particular cases when n == 2,3 we present an alternative closed form to compute the principal logarithm. These low dimensional Lie groups play an important role in the kinematic motion of many mechanical systems and, for that reason, the results presented here have immediate applications in robotic

A Low Cost and Highly Parameterizable Energy Meter

The popularity of the Internet of Things (IoT) and demand for smart devices, particularly in the smart home industry, has increased in recent years. As a result, there is a growing need for affordable and functional energy meters to measure electric energy consumption, mainly due to the rise of electric vehicle (EV) sales and energy prices in Europe. In this paper, we present the development of an energy meter that accurately measures voltage, current, active power, frequency, and power factor. The energy meter is designed to provide information to an intelligent EVSE (Electric Vehicle Supply Equipment), allowing users to "plug and forget." We describe the hardware and software of the latest energy monitor version, including an ESP8266 microcontroller, a PZEM-004TV3 energy meter, an OLED display, and a power supply circuit board. We also present some results of the energy meter’s use, highlighting its functionalities and benefits. The paper concludes with insights into a new version planned for the energy monitor. This paper will be of interest to researchers and industry professionals working in the IoT and smart device fields, as well as those interested in energy efficiency and EV charging infrastructure.info:eu-repo/semantics/publishedVersio