Hybrid intelligent framework for automated medical learning

This paper investigates the automated medical learning and proposes hybrid intelligent framework, called Hybrid Automated Medical Learning (HAML). The goal is the efficient combination of several intelligent components in order to automatically learn the medical data. Multi agents system is proposed by using distributed deep learning, and knowledge graph for learning medical data. The distributed deep learning is used for efficient learning of the different agents in the system, where the knowledge graph is used for dealing with heterogeneous medical data. To demonstrate the usefulness and accuracy of the HAML framework, intensive simulations on medical data were conducted. A wide range of experiments were conducted to verify the efficiency of the proposed system. Three case studies are discussed in this research, the first case study is related to process mining, and more precisely on the ability of HAML to detect relevant patterns from event medical data. The second case study is related to smart building, and the ability of HAML to recognize the different activities of the patients. The third one is related to medical image retrieval, and the ability of HAML to find the most relevant medical images according to the image query. The results show that the developed HAML achieves good performance compared to the most up-to-date medical learning models regarding both the computational and cost the quality of returned solutionspublishedVersio

Low Computational Cost Hybrid Approach for Near-Field RFID Tag Localization

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Electrocaloric effect and energy storage in lead free Gd0.02Na0.5Bi0.48TiO3 ceramic

International audienceThe electrocaloric effect (EC) was investigated in the ferroelectric lead-free Gd0.02Na0.5Bi0.48TiO3 (GdNBT) ceramics. A pure perovskite structure was observed by the X-ray diffraction in GdNBT ceramics synthesized by a solid-state reaction method. Dielectric measurements revealed the existence of different ferroelectric and antiferroelectric transformations in this material. Based on the temperature dependence of P-E loops, reversible electrocaloric temperature changes of about Delta T = 0.75 K at the electric field of 90 kV/cm and the EC responsivity Delta T/Delta E approximate to 0.08 x 10(-6) K m V-1 were obtained in the GdNBT ceramics. The energy-storage density W = 0.85 J cm(-3) and the associated efficiency (eta = 65%) at 413 K were determined from the P-E loops data. The simultaneous existence of EC responsivity and energy-storage density makes GdNBT very promising lead-free material and opens a great potential for its application in electronic devices. (C) 2017 Elsevier Masson SAS. All rights reserved

Dielectric properties and relaxation phenomena in the diffuse ferroelectric phase transition in K

Structural and dielectric properties of Potassium Lithium Niobate polycrystalline ceramic K3Li2Nb5O15 (KLN), having the tetragonal tungsten bronze (TTB) – type structure are studied in the temperature interval 50−550 °C. Special emphasis is given to the diffuse phase transition occurring around 440 °C. Space charge polarization, relaxation phenomena and free charge conductivity have been elucidated using impedance spectroscopy technique. Argand plots have revealed a non Debye and polydispersive type relaxation. In paraelectric phase the Arrhenius activation energy Eτ = 0.533 eV was determined. The structural and dielectric results are compared with two others TTB compounds derived from KLN family: Pb1.85K1.15Li0.15Nb5O15 (PKLN) and GdK2Nb5O15 (GKN)

Effect of CdSe nanoparticles incorporation on the performance of P3OT organic photovoltaic cells

International audiencePhotoluminescence and photovoltaic properties of P3OT:%CdSe nanocomposite films are investigated as a function of the mass concentration (wt%) of the CdSe nanoparticles (NPs) incorporated in the films. The incorporation of CdSe NPs produces a quenching of the photoluminescence and improves the performance of the nanocomposite solar cells. These effects are explained in terms of exciton dissociation and charge separation occurring at P3OT/CdSe interfaces within the Forster formalism, involving non-radiative energy transfer from the donor (P3OT) to the acceptor (CdSe NPs). An exciton quenching rate constant of 1.4 x 10(-10) cm(3) s(-1) is determined using the Stern-Volmer equation. In addition, scanning electron microscopy (SEM) images reveal that surface morphology is changed by CdSe NPs incorporation, in agreement with FTIR spectra. The current density-voltage (I-V) characteristics of ITO/P3OT:%CdSe/Al photovoltaic cells performed for different CdSe concentrations are also reported and indicate a significant improvement of the photovoltaic parameters cells, particularly, the conversion efficiency becomes 20 times greater than that of the cell based on pure polymer. (C) 2015 Elsevier Ltd. All rights reserved

Large imprint in epitaxial 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3thin films for piezoelectric energy harvesting applications

Tuning and stabilizing a large imprint in epitaxial relaxor ferroelectric thin films is one of the key factors for designing micro-electromechanical devices with an enhanced figure of merit (FOM). In this work, epitaxial 500 nm-thick 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 (PMN-33PT) films, free from secondary phases and with extremely low rocking curves (FWHM < 0.05°), are grown on ScSmO3 (SSO) and DyScO3 (DSO) substrates buffered with SrRuO3 (SRO). The PMN-33PT is observed to grow coherently on SSO substrates (lattice mismatch of -0.7%), which is c-axis oriented and exhibits large tetragonality compared to bulk PMN-33PT, while on DSO substrates (lattice mismatch of -1.9%), the PMN-33PT film is almost completely relaxed and shows reduced tetragonality. Due to the compressive epitaxial strain, the fully strained PMN-33PT film displays typical ferroelectric P-E hysteresis loops, while the relaxed sample shows relaxor-like P-E loops. Samples present large negative imprints of about -88.50 and -49.25 kV/cm for PMN-33PT/SRO/SSO and PMN-33PT/SRO/DSO, respectively, which is more than threefold higher than the coercive field. The imprint is induced by the alignment of defect dipoles with the polarization and is tuned by the epitaxial strain. It permits the stabilization of a robust positive polarization state (Pr ∼20 μC/cm2) and low dielectric permittivity (<700). In addition, the relaxed PMN-33PT film shows improved piezoelectric properties, with a 33% enhancement in d33,eff relative to the fully strained sample. The obtained low dielectric permittivity and the high piezoelectric coefficients at zero electric field in the studied PMN-33PT films hold great promise to maximize the FOM toward applications in piezoelectric devices

Phonons heat transport at an atomic well boundary in ultrathin solid films

A model calculation is presented for the heat transport across an extended atomic well boundary separating two ultrathin solid films, due to the phonons coherent elastic scattering at the boundary. Using the matching method, the transmission spectra are calculated for the phonons coherent scattering, for all propagating frequencies, and incident angles from inside the films, and for different boundary elastic conditions. The group velocities of the phonon branches in the ultrathin material films are explicitly calculated as a function of frequency and incidence angle. The model is applied to a corresponding gold material system, where the individual thermal conductivities for the phonon branches of this system are numerically evaluated for different boundary conditions. The results show that the heat transport at the boundary may be reduced or enhanced by controlling its elastic properties. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2011