526 research outputs found

    Cancer diagnosis using deep learning: A bibliographic review

    Get PDF
    In this paper, we first describe the basics of the field of cancer diagnosis, which includes steps of cancer diagnosis followed by the typical classification methods used by doctors, providing a historical idea of cancer classification techniques to the readers. These methods include Asymmetry, Border, Color and Diameter (ABCD) method, seven-point detection method, Menzies method, and pattern analysis. They are used regularly by doctors for cancer diagnosis, although they are not considered very efficient for obtaining better performance. Moreover, considering all types of audience, the basic evaluation criteria are also discussed. The criteria include the receiver operating characteristic curve (ROC curve), Area under the ROC curve (AUC), F1 score, accuracy, specificity, sensitivity, precision, dice-coefficient, average accuracy, and Jaccard index. Previously used methods are considered inefficient, asking for better and smarter methods for cancer diagnosis. Artificial intelligence and cancer diagnosis are gaining attention as a way to define better diagnostic tools. In particular, deep neural networks can be successfully used for intelligent image analysis. The basic framework of how this machine learning works on medical imaging is provided in this study, i.e., pre-processing, image segmentation and post-processing. The second part of this manuscript describes the different deep learning techniques, such as convolutional neural networks (CNNs), generative adversarial models (GANs), deep autoencoders (DANs), restricted Boltzmann’s machine (RBM), stacked autoencoders (SAE), convolutional autoencoders (CAE), recurrent neural networks (RNNs), long short-term memory (LTSM), multi-scale convolutional neural network (M-CNN), multi-instance learning convolutional neural network (MIL-CNN). For each technique, we provide Python codes, to allow interested readers to experiment with the cited algorithms on their own diagnostic problems. The third part of this manuscript compiles the successfully applied deep learning models for different types of cancers. Considering the length of the manuscript, we restrict ourselves to the discussion of breast cancer, lung cancer, brain cancer, and skin cancer. The purpose of this bibliographic review is to provide researchers opting to work in implementing deep learning and artificial neural networks for cancer diagnosis a knowledge from scratch of the state-of-the-art achievements

    Lezioni di Campi Elettromagnetici I

    Get PDF
    terza edizione, versione LaTeX a cura di Mauro Mineo. Le edizioni precedenti erano disponibili in formato elettronico in ret

    Lezioni di Campi Elettromagnetici II

    Get PDF
    nona edizione, versione LaTeX a cura di Alessandro Ciorba. Le edizioni precedenti erano disponibili in formato elettronico in ret

    Electromagnetic Scattering by a Cylinder in a Lossy Medium of an Inhomogeneous Elliptically Polarized Plane Wave, Journal of Telecommunications and Information Technology, 2019, nr 4

    Get PDF
    In this paper, a rigorous theoretical approach, adopted in order to generalize the Vectorial CylindricalHarmonics (VCH) expansion of an inhomogeneous elliptically polarized plane wave, is presented. An application of the VCH expansion to analyze electromagnetic field scattered by an infinite circular cylinder is presented. The results are obtained using the so-called complex-angle formalism reaching a superposition of Vectorial Cylindrical-Harmonics. To validate the method, a Matlab code was implemented. Also, the validity of the methodology was confirmed through some comparisons between the proposed method and the numerical results obtained based on the Finite Element Method (FEM) in the canonical scenario with a single cylinde

    Detection of a misaligned broken pipe by electromagnetic interaction

    Get PDF
    The study we are presenting concerns electromagnetic scattering of a plane wave due to the presence of a misaligned broken pipe buried in a half-space occupied by cement and by asphalt/ground, for civil-engineering applications

    Radiation-Enhancement Properties of an X-Band Woodpile EBG and Its Application to a Planar Antenna

    Get PDF
    A woodpile Electromagnetic Bandgap (EBG) material has been designed, by using an in-house code that implements the Fourier Modal Method (FMM). A couple of alumina-woodpile samples have been fabricated. Several results have been collected for the transmission behaviour of the woodpile and of resonators with woodpile mirrors, in a shielded anechoic chamber, by using a vector network analyzer, in the 8–12 GHz range. These new experimental data highlight interesting properties of 3D EBG resonators and suggest possible innovative applications. Comparisons of the collected results with FMM show a satisfactory agreement. An application of the EBG resonator has been considered, for gain enhancement of a microstrip antenna: an increase of about 10 dB in the broadside gain has been measured; experimental data and numerical results obtained with the commercial software HFSS show a good agreement. A comparison is presented between EBG resonator antennas and two-dimensional uniform arrays. Finally, HFSS results are provided for EBG resonator antennas working at higher frequencies or with a more selective superstrate: a gain enhancement of more than 18 dB is achieved by such antennas

    Polarization-maintaining reflection-mode THz time-domain spectroscopy of a polyimide based ultra-thin narrow-band metamaterial absorber

    Get PDF
    This paper reports the design, the microfabrication and the experimental characterization of an ultra-thin narrow-band metamaterial absorber at terahertz frequencies. The metamaterial device is composed of a highly flexible polyimide spacer included between a top electric ring resonator with a four-fold rotational symmetry and a bottom ground plane that avoids misalignment problems. Its performance has been experimentally demonstrated by a custom polarization-maintaining reflection-mode terahertz time-domain spectroscopy system properly designed in order to reach a collimated configuration of the terahertz beam. The dependence of the spectral characteristics of this metamaterial absorber has been evaluated on the azimuthal angle under oblique incidence. The obtained absorbance levels are comprised between 67% and 74% at 1.092 THz and the polarization insensitivity has been verified in transverse electric polarization. This offers potential prospects in terahertz imaging, in terahertz stealth technology, in substance identification, and in non-planar applications. The proposed compact experimental set-up can be applied to investigate arbitrary polarization-sensitive terahertz devices under oblique incidence, allowing for a wide reproducibility of the measurements

    Electromagnetic Scattering of Inhomogeneous Plane Wave by Ensemble of Cylinders, Journal of Telecommunications and Information Technology, 2020, nr 3

    Get PDF
    The interaction between an ensemble of cylinders and an inhomogeneous plane wave is introduced and is determined, in the present paper, through a rigorous theoretical approach. Scattered electromagnetic field generated by an indefinite number of infinite circular cylinders is analyzed by the application of the generalized vector cylinder harmonics (VCH) expansion. The exact mathematical model relied upon to represent this scenario considers the so-called complex-angle formalism reaching a superposition of vectorial cylindrical-harmonics and Foldy-Lax Multiple scattering equations (FLMSE) to account for the multiscattering process between the cylinders. The method was validated by comparing the numerical results obtained with the use of the finite element method and a homemade Matlab cod

    Analytical Investigation on a New Approach for Achieving Deep Penetration in a Lossy Medium: The Lossy Prism, Journal of Telecommunications and Information Technology, 2017, nr 3

    Get PDF
    Recent studies highlighted deep-penetration prop-erties of inhomogeneous waves at the interface between a loss-less and a lossy medium. Such waves can be generated bymeans of radiating structures known as Leaky-Wave Anten-nas (LWAs). Here, a different approach is proposed basedon the use of a lossy prism capable to generate an inhomo-geneous wave when illuminated by a homogeneous wave. Thelossy prism is conceived and designed thinking of Ground-Penetrating Radar (GPR). The results achieved by the lossyprism will be compared with those obtained by means of a pre-viously designed LWA that was created with the identical ob-jective. The approach of this paper is purely theoretical, andit aims at providing basic ideas and preliminary results usefulfor an innovative LWA design
    corecore