520 research outputs found

    Evolutionary optimization of neural networks with heterogeneous computation: study and implementation

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    In the optimization of artificial neural networks (ANNs) via evolutionary algorithms and the implementation of the necessary training for the objective function, there is often a trade-off between efficiency and flexibility. Pure software solutions on general-purpose processors tend to be slow because they do not take advantage of the inherent parallelism, whereas hardware realizations usually rely on optimizations that reduce the range of applicable network topologies, or they attempt to increase processing efficiency by means of low-precision data representation. This paper presents, first of all, a study that shows the need of heterogeneous platform (CPU–GPU–FPGA) to accelerate the optimization of ANNs using genetic algorithms and, secondly, an implementation of a platform based on embedded systems with hardware accelerators implemented in Field Pro-grammable Gate Array (FPGA). The implementation of the individuals on a remote low-cost Altera FPGA allowed us to obtain a 3x–4x acceleration compared with a 2.83 GHz Intel Xeon Quad-Core and 6x–7x compared with a 2.2 GHz AMD Opteron Quad-Core 2354.The translation of this paper was funded by the Universitat Politecnica de Valencia, Spain.Fe, JD.; Aliaga Varea, RJ.; Gadea Gironés, R. (2015). Evolutionary optimization of neural networks with heterogeneous computation: study and implementation. The Journal of Supercomputing. 71(8):2944-2962. doi:10.1007/s11227-015-1419-7S29442962718Farmahini-Farahani A, Vakili S, Fakhraie SM, Safari S, Lucas C (2010) Parallel scalable hardware implementation of asynchronous discrete particle swarm optimization. Eng Appl Artif Intell 23(2):177–187Curteanu S, Cartwright H (2011) Neural networks applied in chemistry. i. Determination of the optimal topology of multilayer perceptron neural networks. 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DaWaK02, pp 170–180Fe J, Aliaga RJ, Gironés RG (2013) Experimental platform for accelerate the training of anns with genetic algorithm and embedded system on fpga. In: IWINAC (2), pp 413–420Prechelt L (1994) Proben1—a set of neural network benchmark problems and benchmarking rules. Technical reportAbbass HA (2002) An evolutionary artificial neural networks approach for breast cancer diagnosis. Artif Intell Med 25:265–281Ahmad F, Isa NAM, Hussain Z, Sulaiman SN (2013) A genetic algorithm-based multi-objective optimization of an artificial neural network classifier for breast cancer diagnosis. Neural Comput Appl 23(5):1427–1435Sankaradas M, Jakkula V, Cadambi S, Chakradhar S, Durdanovic I, Cosatto E, Graf H (2009) A massively parallel coprocessor for convolutional neural networks. In: Application-specific systems, architectures and processors, 2009. ASAP 2009. 20th IEEE international conference on, July, pp 53–60Prado R, Melo J, Oliveira J, Neto A (2012) Fpga based implementation of a fuzzy neural network modular architecture for embedded systems. In: Neural networks (IJCNN), The 2012 international joint conference on, June, pp 1–7Çavuşlu M, Karakuzu C, Sahin S, Yakut M (2011) Neural network training based on fpga with floating point number format and its performance. Neural Comput Appl 20:195–202. doi: 10.1007/s00521-010-0423-3Wu G-D, Zhu Z-W, Lin B-W (2011) Reconfigurable back propagation based neural network architecture. In: Integrated circuits (ISIC), 2011 13th international symposium on, Dec, pp 67–70Pinjare SL, Kumar A (2012) Implementation of neural network back propagation training algorithm on fpga. Int J Comput Appl 52(6): 1–7, August, published by Foundation of Computer Science, New York, USAhttp://www.altera.comAliaga R, Gadea R, Colom R, Cerda J, Ferrando N, Herrero V (2009) A mixed hardware–software approach to flexible artificial neural network training on fpga. In: Systems, architectures, modeling, and simulation, 2009. SAMOS ’09. International symposium on, July, pp 1–8http://www.matlab.co

    National Temporal Trend Analysis of Infective Endocarditis among Patients Infected with HIV in Spain (1997-2014): A Retrospective Study

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    BACKGROUND: People living with human immunodeficiency virus (HIV) (PLWH) form a vulnerable population for the onset of infective endocarditis (IE). We aimed to analyze the epidemiological trend of IE, as well as its microbiological characteristics, in PLWH during the combined antiretroviral therapy era in Spain. METHODS: We performed a retrospective study (1997-2014) in PLWH with data obtained from the Spanish Minimum Basic Data Set. We selected 1800 hospital admissions with an IE diagnosis, which corresponded to 1439 patients. RESULTS: We found significant downward trends in the periods 1997-1999 and 2008-2014 in the rate of hospital admissions with an IE diagnosis (from 21.8 to 3.8 events per 10,000 patients/year; p < 0.001), IE incidence (from 18.2 to 2.9 events per 10,000 patients/year; p < 0.001), and IE mortality (from 23.9 to 5.5 deaths per 100,000 patient-years; p < 0.001). The most frequent microorganisms involved were staphylococci (50%; 42.7% Staphylococcus aureus and 7.3% coagulase-negative staphylococci (CoNS)), followed by streptococci (9.3%), Gram-negative bacilli (8.3%), enterococci (3%), and fungus (1.4%). During the study period, we found a downward trend in the rates of CoNS (p < 0.001) and an upward trends in streptococci (p = 0.001), Gram-negative bacilli (p < 0.001), enterococci (p = 0.003), and fungus (p < 0.001) related to IE, mainly in 2008-2014. The rate of community-acquired IE showed a significant upward trend (p = 0.001), while the rate of health care-associated IE showed a significant downward trend (p < 0.001). CONCLUSIONS: The rates of hospital admissions, incidence, and mortality related to IE diagnosis in PLWH in Spain decreased from 1997 to 2014, while other changes in clinical characteristics, mode of acquisition, and pathogens occurred over this time.This research has been supported by Instituto de Salud Carlos III (grant numbers PI15/01451 to ET), and “Gerencia de Salud, Consejería de Sanidad, Junta de Castilla y Leon” [grant number 773/A/13 to ET].S

    Improving FPGA Based Impedance Spectroscopy Measurement Equipment by Means of HLS Described Neural Networks to Apply Edge AI

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    [EN] The artificial intelligence (AI) application in instruments such as impedance spectroscopy highlights the difficulty to choose an electronic technology that correctly solves the basic performance problems, adaptation to the context, flexibility, precision, autonomy, and speed of design. Present work demonstrates that FPGAs, in conjunction with an optimized high-level synthesis (HLS), allow us to have an efficient connection between the signals sensed by the instrument and the artificial neural network-based AI computing block that will analyze them. State-of-the-art comparisons and experimental results also demonstrate that our designed and developed architectures offer the best compromise between performance, efficiency, and system costs in terms of artificial neural networks implementation. In the present work, computational efficiency above 21 Mps/DSP and power efficiency below 1.24 mW/Mps are achieved. It is important to remark that these results are more relevant because the system can be implemented on a low-cost FPGA.This work was supported in part by the Spanish MCIU under Project PID2020-116816RB-I00 (MCIU/FEDER) and in part by GVA under Project INNEST/2020/248.Fe, J.; Gadea Gironés, R.; Monzó Ferrer, JM.; Tébar Ruiz, Á.; Colom Palero, RJ. (2022). Improving FPGA Based Impedance Spectroscopy Measurement Equipment by Means of HLS Described Neural Networks to Apply Edge AI. Electronics. 11(13):1-14. https://doi.org/10.3390/electronics11132064114111

    Empleo de nuevos medios para control de labores de mantenimiento y repuestos

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    Hoy en día, el Ejército de Tierra busca mejorar sus procesos y capacidades para recopilar y guardar información de una forma sencilla y dinámica. Es por ello que, mediante la ayuda de aplicaciones informáticas, se pueden optimizar muchas de las diferentes tareas que se realizan día a día en las diferentes unidades.El Grupo de Artillería de Campaña XI (GACA XI) tiene la necesidad de sumarse a esta mejora continua. El GACA XI precisa actualmente de una aplicación informática de uso sencillo e intuitivo para mejorar el control de labores de mantenimiento y repuestos. Es por ello que en la primera parte del trabajo se ha tratado de concretar las necesidades y requerimientos del GACA XI. Tras realizar una serie de reuniones con los mandos del GACA XI, se han llevado a cabo una serie de estudios como son el análisis de los stakeholders, en el cual se estudian las partes interesadas en el desarrollo e implantación de la aplicación informática en el GACA XI, y un análisis funcional para determinar los diversos casos de uso necesarios para el correcto funcionamiento de la aplicación como son: pedir nombre de usuario y clave, distinguir el tipo de usuario, gestionar una declaración o actualizar el estado operativo de las piezas, y acceder a diferentes opciones.Como continuación del análisis de funcionalidades realizado, se ha desarrollado una aplicación informática mediante Microsoft Access para que pueda ser utilizada en los diversos ordenadores del Ejército de Tierra. Las bases de datos y los formularios interactivos se han creado con la ayuda de Microsoft Access y el código informático requerido para el funcionamiento de la aplicación ha sido elaborado con el lenguaje de programación Visual Basic, el cual ha servido para realizar tareas como actualizar las bases de datos o enlazar las diferentes bases de datos elaboradas con los formularios correspondientes.La aplicación diferencia entre dos tipos de usuarios: usuarios genéricos y administrador de sistema. Según el tipo de usuario identificado por la aplicación, existen diferentes menús con diversas opciones para garantizar un control completo en las tareas de mantenimiento y repuestos. Opciones como actualizar el estado de mantenimiento de las piezas de artillería o declarar necesidades de falta de repuestos están disponibles para los usuarios genéricos de la aplicación. Por otro lado, para garantizar el control en las tareas de mantenimiento y repuestos, el administrador del sistema puede observar el estado de mantenimiento actual de las piezas y las declaraciones de falta de repuestos realizadas por todos los usuarios genéricos, entre otras opciones.En la parte final del trabajo se ha analizado la viabilidad de la implementación de la aplicación desarrollada en el GACA XI. Se han realizado diversos estudios para analizar la aplicación desde una parte tanto técnica, mediante múltiples pruebas del funcionamiento de la aplicación, como económica, calculando los costes totales de la aplicación a lo largo de su ciclo de vida. Además, se han obtenido valoraciones y sugerencias de importancia, recogidas en una encuesta realizada por parte de los futuros usuarios de la aplicación, las cuales pueden ser utilizadas para futuros desarrollos.<br /

    Novel optoelectronic platform for label-free biosensing of influenza detection based on interferometric transducers

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    The main goal of this project is to present an Optical Label-free Point-ofCare Device based on a novel read-out methodology that enhances significantly the biosensing response in terms of sensitivity and LoD, using a simple, fast and reliable interrogation process. The performance of this PoC device is verified by carrying out the calibration curve for the indirect immunoassay of Influenza Virus and comparing it with high-resolution spectrometry using the same Fabry-Perot interferometers as biosensors

    Nosocomial Vs. Community-Acquired Infective Endocarditis in Spain: Location, Trends, Clinical Presentation, Etiology, and Survival in the 21st Century

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    Major changes have occurred in the epidemiology and etiology of infective endocarditis (IE). Nevertheless, the differences between nosocomial infective endocarditis (NIE) and community-acquired infective endocarditis (CIE) have not been addressed in a population-based study. We conducted a retrospective, nationwide, temporal trend study from 1997 to 2014 analyzing the epidemiology, clinical, geographical, meteorological characteristics of patients diagnosed with IE in Spain, to distinguish NIE from CIE. Among 25,952 patients with IE (62.2 ± 18·6 years; 65.9% men), 45.9% had NIE. The incidence of IE increased from 2.83 to 3.73 due to the NIE incidence increment with a decline in CIE. Patients with NIE were older (63.8 years vs. 60.8 years, p < 0·001), presented a higher Charlson index (1.22 vs. 1.03, p < 0.001), a greater history of implanted cardiac devices (8.7% vs. 4.6%, p < 0.001), and higher mortality (31.5% vs. 21.7%, p < 0.001). The most frequent microorganism for both NIE and CIE was Staphylococcus (p < 0.001), and the North reported a higher incidence (p < 0.001). Risk factors of mortality for NIE were age, Charlson index, hemodialysis, shock, heart failure, and stroke. Risk factors for CIE included female sex, renal disease, and cardiac-device carriers. The etiology of IE shifted from community origins to mostly nosocomial-associated infections. Higher morbidity, mortality, and poorer outcomes are associated with NIE.This research received no external funding. The authors thank Consejería de Educación, Junta de Castilla y León, Spain (reference: VA161G18), for covering the publication charges of this article.S

    Activity of imipenem/relebactam against Enterobacterales and Pseudomonas aeruginosa in Spain. SMART 2016-2020

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    Objectives. To determine susceptibility to the novel β-lactam/β-lactamase inhibitor combination imipenem/relebactam in clinical isolates recovered from intra-abdominal (IAI), urinary (UTI), respiratory (RTI) and bloodstream (BSI) infections in the SMART (Study for Monitoring Antimicrobial Resistance Trends) study in SPAIN during 2016 – 2020. Methods. Broth microdilution MICs for imipenem/relebactam and comparators were determined by a central laboratory against isolates of Enterobacterales and Pseudomonas aeruginosa. MICs were interpreted using EUCAST-2021 breakpoints. Results. In total, 5,210 Enterobacterales and 1,418 P. aeruginosa clinical isolates were analyzed. Imipenem/relebactam inhibited 98.8% of Enterobacterales. Distinguishing by source of infection susceptibility was 99.1% in BSI, 99.2% in IAI, 97.9% in RTI, and 99.2% in UTI. Of intensive care unit isolates (ICU) 97.4% were susceptible and of non-ICU isolates 99.2% were susceptible. In Enterobacterales, activity against Class A, Class B and Class D carbapenemases was 96.2%, 15.4% and 73.2%, respectively. In P. aeruginosa, imipenem/relebactam was active in 92.2% of isolates. By source of infection it was 94.8% in BSI, 92.9% in IAI, 91.7% in RTI, and 93.1% in UTI. An 88.7% of ICU isolates and 93.6% of non-ICU isolates were susceptible to imipenem/relebactam. Imipenem/relebactam remained active against P. aeruginosa ceftazidime-resistant (76.3%), cefepime-resistant (73.6%), imipenem-resistant (71.5%) and piperacillin-resistant (78.7%) isolates. Of all multidrug-resistant or difficult-to-treat resistance P. aeruginosa isolates, 75.1% and 46.2%, respectively, were susceptible to imipenem/relebactam. Conclusions. Imipenem/relebactam showed high rates of susceptibility in Enterobacterales and P. aeruginosa isolates from different sources of infection as well as depending on patients’ location (ICU or non-ICU scenarios)

    Antibody-Based Detection and Inhibition of Vaginolysin, the Gardnerella vaginalis Cytolysin

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    Bacterial vaginosis (BV) is the most common vaginal infection worldwide and is associated with significant adverse sequelae. We have recently characterized vaginolysin (VLY), the human-specific cytotoxin produced by Gardnerella vaginalis and believed to play a critical role in the pathogenesis of BV and its associated morbidities. We hypothesize that novel antibody-based strategies may be useful for detection of VLY and for inhibition of its toxic effects on human cells. Using purified toxin as an immunogen, we generated polyclonal rabbit immune serum (IS) against VLY. A western blot of G. vaginalis lysate was probed with IS and a single band (57 kD) identified. Immunofluorescence techniques using IS detected VLY production by G. vaginalis. In addition, we have developed a sandwich ELISA assay capable of VLY quantification at ng/ml concentrations in the supernatant of growing G. vaginalis. To investigate the potential inhibitory role of IS on VLY-mediated cell lysis, we exposed human erythrocytes to VLY or VLY pretreated with IS and determined the percent hemolysis. Pretreatment with IS resulted in a significant reduction in VLY-mediated lysis. Similarly, both human cervical carcinoma cells and vaginal epithelial cells exhibited reduced cytolysis following exposure to VLY with IS compared to VLY alone. These results confirm that antibody-based techniques are an effective means of VLY detection. Furthermore, VLY antiserum functions as an inhibitor of VLY–CD59 interaction, mitigating cell lysis. These strategies may have a potential role in the diagnosis and treatment of BV

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration
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