Fabrizio Frezza

Verified

Fabrizio verified their affiliation via an institutional email.

Learn more

Verified

Fabrizio verified their affiliation via an institutional email.

Learn more

• Ph.D. in Applied Electromagnetics and Electrophysical Sciences
• Professor (Full) in Electromagnetic Fields at Sapienza University of Rome

This study presents a cost-effective Hybrid Metamaterial Absorber (HMA) featuring a simple circular-patterned cylindrical design, comprising an indium antimonide (InSb) resonator on a thin copper sheet. Through numerical simulations, we demonstrate that the structure exhibits temperature-tunable properties and refractive index sensitivity. At 300 K...

When discussing Cultural Heritage (CH), the risk of causing damage is inherently linked to the artifact itself due to several factors: age, perishable materials, manufacturing techniques, and, at times, inadequate preservation conditions or previous interventions. Thorough study and diagnostics are essential before any intervention, whether for pre...

Statistical mechanics permits to connect the macroscopic properties of matter with the laws governing the evolution of its microscopic constituents. Such an approach has been very successful for systems of particles governed by either classical or quantum mechanics. In a classical gas, different thermodynamic laws apply to the weakly or strongly in...

Featured Application We want to provide a useful tool to introduce the readers to the Electromagnetic techniques applied to CH conservation. Abstract Cultural Heritage (CH) represents the identity of populations; it is a heritage not only for the culture that produced it, but also for the entire human civilization. Still, preserving it is not an e...

For this article, we approximated the field of a leaky-wave antenna (LWA) with the field produced by a uniform linear array (ULA). This article aims to provide an initial framework for applications where the generation of an inhomogeneous wave is wished, but, at the same time, a flexibility is required that is difficult to meet with the conventiona...

Functional magnetic resonance imaging time-series are conventionally processed by linear modelling the evoked response as the convolution of the experimental conditions with a stereotyped haemodynamic response function (HRF). However, the neural signal in response to a stimulus can vary according to task, brain region, and subject-specific conditio...

We present our findings on the direct conversion of a Gaussian-like laser beam, which was initially injected into the cladding of a graded-index multimode fiber, into a high-order Laguerre-Gauss mode within the core of the fiber.

We report our observation of a direct transformation of a Gaussian-like laser beam, initially injected into the cladding of a graded-index multimode fiber (MMF), into a high-order Laguerre–Gauss (LG) mode within the fiber core.

Diffractive optical elements that divide an input beam into a set of replicas are used in many optical applications ranging from image processing to communications. Their design requires time-consuming optimization processes, which, for a given number of generated beams, are to be separately treated for one-dimensional and two-dimensional cases bec...

This research proposes an all-metal metamaterial-based absorber with a novel geometry capable of refractive index sensing in the terahertz (THz) range. The structure consists of four concentric diamond-shaped gold resonators on the top of a gold metal plate; the resonators increase in height by 2 µm moving from the outer to the inner resonators, ma...

We present preliminary work leading to feasibility study for the construction of a shield of a space probe to cosmic radiation as based on magnetic deviation by mean of neodymium permanent magnets. The choice of permanent magnets is the main novelty of our project. The first aim is to protect the health of astronauts inhabiting the space probe by t...

Here, inhomogeneous waves, and, in particular, leaky waves are initially described and natural phenomena that can be expressed in terms of inhomogeneous improper waves are also introduced. The description of the physical properties of inhomogeneous waves and leaky waves and their physical characteristics will finally allow us to describe the propag...

New solutions to an old problem: how to magnetically shield astronauts from radiation

The analytical-numerical evaluation of the scattering of electromagnetic waves by multiple spheres requires the computation of numerous coefficients. For this purpose, many contributions, available in the literature, have traditionally employed the recursion method. In the present paper, we introduce a novel approach, based on primes and indices, w...

Computer-aided diagnosis (CAD) systems, which combine medical image processing with artificial intelligence (AI) to support experts in diagnosing various diseases, emerged from the need to solve some of the problems associated with medical diagnosis, such as long timelines and operator-related variability. The most explored medical application is c...

Background: Hepatocellular carcinoma (HCC) exhibits an exceptional intratumoral heterogeneity that might influence diagnosis and outcome. Advances in digital microscopy and artificial intelligence (AI) may improve the HCC identification of liver cancer cells. Aim: Two AI algorithms were designed to perform computer-assisted discrimination of tumour...

Here, inhomogeneous waves, and, in particular, leaky waves are initially described and natural phenomena that can be expressed in terms of inhomogeneous improper waves are also introduced. The description of the physical properties of inhomogeneous waves and leaky waves and their physical characteristics will finally allow us to describe the propag...

This study was aimed at introducing a new method for predicting the original metrics of fragmented standardized artifacts, specifically of flint blades from the Middle Pre-Pottery Neolithic B (10,200/100–9,500/400 cal B.P.) in the Southern Levant. The excessive re-use of these artifacts or poor preservation conditions often prevent a complete set o...

The Pre-Pottery Neolithic B is conventionally recognised as a homogeneous cultural aspect during the Neolithic of the Levant, which develops in more phytogeographical ecozones (e.g., Mediterranean, steppe, desertic ecozone, etc.) and in several chrono-cultural phases that spread with throughout different times first in the northern Levant and then...

L'applicazione del machine learning ai beni culturali permette di apprendere o recuperare informazioni che altrimenti andrebbero perdute per sempre. I modelli ad apprendimento automatico permettono infatti di effettuare previsioni più precisi possibili. Questo approccio, se applicato alla cultura materiale come industria litica, ceramica o strument...

The aim of the present work is to try to understand whether, using the original (unprocessed) dermoscopic images and the additional texture information from the whole (unsegmented) images, a Convolutional Neural Network (CNN) can effectively distinguish between nevi and melanomas, which have similar features and are therefore difficult to diagnose.

The Pre-Pottery Neolithic B phase (10,600-9,000 years Cal B.P) is highly characterised by laminar production all over the Levant (Syria, Lebanon, Jordan and Israel) and South-eastern Anatolia (Turkey). This specific chrono-cultural phase consists of a specific reduction process that is aimed to produce mainly blades and secondarily bladelets. The l...

Malaria is a disease that affects millions of people worldwide with a consistent mortality rate. The light microscope examination is the gold standard for detecting infection by malaria parasites. Still, it is limited by long timescales and requires a high level of expertise from pathologists. Early diagnosis of this disease is necessary to achieve...

Optimization of machine learning architectures is essential in determining the efficacy and the applicability of any neural architecture to real world problems. In this work a generalized Newton's method (GNM) is presented as a powerful approach to learning in deep neural networks (DNN). This technique was compared to two popular approaches, namely...

Machine learning algorithms have revolutionized data analysis by uncovering hidden patterns and structures. Clustering algorithms play a crucial role in organizing data into coherent groups. We focused on K-Means, hierarchical, and Self-Organizing Map (SOM) clustering algorithms for analyzing homogeneous datasets based on archaeological finds from...

Compact, energy-efficient, and autonomous wireless sensor nodes offer incredible versatility for various applications across different environments. Although these devices transmit and receive real-time data, efficient energy storage (ES) is crucial for their operation, especially in remote or hard-to-reach locations. Rechargeable batteries are com...

Nanostructured metamaterials are now commonplace in contemporary photonics, providing a means for tailored manipulation of light-matter interactions. By deliberately altering the spatial distribution of materials at sub-wavelength scales, these materials yield optical responses surpassing those seen in natural counterparts. Among these, thin-film m...

L'obiettivo del nostro studio è valutare la capacità dei medici non esperti di effettuare uno screening preliminare delle lesioni cutanee al fine di identificare quelle che richiedono un'indagine specialistica. Accorciare il tempo di diagnosi avrebbe importanti implicazioni non solo sulla prognosi, ma anche sull'intero Sistema Sanitario Nazionale....

This study aims to present a comparative analysis of the Bayesian regularization backpropagation and Levenberg–Marquardt training algorithms in neural networks for the metrics prediction of damaged archaeological artifacts, of which the state of conservation is often fragmented due to different reasons, such as ritual, use wear, or post-depositiona...

We present a direct experimental study of the evolution of the optical entropy of a multimode light beam propagating in a graded-index optical fiber.

The application of artificial intelligence in the medical field has increased significantly in recent decades. When diagnosis requires long timelines and is strongly influenced by inter- and intra-operator variability, computer-aided diagnosis (CAD) systems have been developed that take advantage of machine learning (ML) and deep learning (DL) appr...

This project aims to develop and validate innovative methods for the analysis and synthesis of intelligent surfaces and metamaterials, with special emphasis on electromagnetic and audio waves. The objectives of the project include the study of existing methods, the formulation of new solutions and the comparison in terms of performance. Special emp...

Diffractive optical elements that divide an input beam into a set of replicas are used in many optical applications ranging from image processing to communications. Their design requires time-consuming optimization processes, which, for a given number of generated beams, are to be separately treated for one-dimensional and two-dimensional cases bec...

Ground-Penetrating Radar (GPR) is an instrument that, without requiring excavations or drilling, uses radar principles to obtain detailed information about the subsurface in a non-invasive manner. Moreover, the application of machine learning (ML) techniques to radar images (radargrams) makes it possible to learn or retrieve information that would...

Introduction Hepatocellular carcinoma (HCC) is the most common primary liver cancer worldwide [1]. Histopathology is crucial for its diagnosis [2], but visual inspection of the architecture of the nuclei is limited by the long time and variety of interpretations. Automatic diagnostic systems could prove to be life-saving tools. To determinate wheth...

Digital pathology (DP) has begun to play a key role in the evaluation of liver specimens. Recent studies have shown that a workflow that combines DP and artificial intelligence (AI) applied to histopathology has potential value in supporting the diagnosis, treatment evaluation, and prognosis prediction of liver diseases. Here, we provide a systemat...

[N.B. una registrazione dell'evento è disponibile al seguente link: https://www.youtube.com/watch?v=OJBnXlYvwwk&t=196s] Il 30 novembre 2022, giorno in cui ChatGPT è stato lanciato al pubblico, è una data che difficilmente verrà rimossa dalla memoria storica. ChatGPT è l’apice di una “rivoluzione cognitiva” che vede come protagonista l’Intelligenz...

This article studies the electrostatic response of a two-dimensional dielectric half-ellipse. A semianalytical method is presented for solving the polarizability of a half-ellipse as a function of its relative permittivity. The polarizability depends on the direction of incident field, and therefore, it is written as a dyadic with two perpendicular...

In this paper, we exploit the enhanced penetration reachable through inhomogeneous waves to induce hyperthermia in biological tissues. We will present a leaky-wave antenna inspired by the Menzel antenna which has been shortened through opportune design and optimizations and that has been designed to optimize the penetration at the interface with th...

L’applicazione del machine learning ai beni culturali permette di apprendere o recuperare informazioni che altrimenti andrebbero perdute per sempre. I modelli ad apprendimento automatico permettono infatti di effettuare previsioni più precisi possibili. Questo approccio, se applicato alla cultura materiale come industria litica, ceramica o strument...

The aim of our work is to develop an algorithm designed to perform a computer-assisted discrimination of tumour from non-tumour nuclei in HepatoCellular Carcinoma (HCC)

The aim of the present work is to try to understand whether, using the original (unprocessed) dermoscopic images and the additional texture information from the whole (unsegmented) images, a Convolutional Neural Network (CNN) can effectively distinguish between nevi and melanomas, which have similar features and are therefore difficult to diagnose

Skin cancer (SC) is one of the most common cancers in the world and is a leading cause of death in humans. Melanoma (M) is the most aggressive form of skin cancer and has an increasing incidence rate. Early and accurate diagnosis of M is critical to increase patient survival rates; however, its clinical evaluation is limited by the long timelines,...

Our algorithm was designed to determine whether a cell of interest is diseased or healthy on the basis of results obtained by applying a plurality of statistical functions chosen to characterize the texture of the nuclei after fluorescent staining with an antibody against proliferating cell nuclear antigen (PCNA) and an anthraquinonoid dye with hig...

This paper is aimed to outline how Guglielmo Marconi’s studies on the applications of ultra short wavelength radio propagation from the beginning of the ‘30s of XX century, have influenced the development of radio systems during and after the second world war. This statement is validated by the many correlations between the experiments carried out...

Dielectric response of pure water and aqueous chlorides solutions at very high frequencies, greater than 1 GHz, can fully be accounted for only considering the relaxation spectral function as the weighted sum of two independent single-parameter Debye functions. Two different relaxation modes are assigned to a collective mode and to an individual mo...

In this work, we propose a heuristic methodology using hydration models as a base to realize an automatic and non-invasive procedure to estimate an ad hoc map of the complex dielectric permittivity of a generic human tissue.

We propose a machine learning analysis as a neural network approach for an automatic reconstruction of missing dimensional data based on a standardised measurements‘ recording of laminar artefacts‘s dimensions.

In this work, we have presented the deep insight of Goos–Hänchen shift depending upon the temperature when a plane incident electromagnetic beam of light enters from a rare to a denser medium, keeping conditions of total internal reflection intact. A simple well known Drude’s model has been used for the purpose of thermal analysis of this shift. Th...

The transmission of light through optical fibers continues to be a major focus for researchers. This study centers on optical fiber Bragg grating (FBG) constituted of cladding and core in two configurations, consequently, for two applications. These two systems contain a Bragg grating placed in the core center. The first optical fiber has FBG withi...

We characterized a deconvolved haemodynamic response function (dHRF) across the whole cortex exploiting a sine series expansion in a cohort of young healthy subjects from the Human Connectome Project. We report, for different tasks and brain regions, the amplitude, latency, time-to-peak and full-width at half maximum of the fitted BOLD response and...

At the molecular level, the body is composed, on average, of water for 62%, fat for 15%, 17% of protein, and 6% of minerals. In this work, we propose a heuristic methodology using hydration models as a base to realize an automatic and noninvasive procedure to estimate an ad hoc map of the complex dielectric permittivity of a generic human tissue in...

The presentation is available at the following YouTube link: https://www.youtube.com/watch?v=dxjcjm_yUew

This paper aims at analyzing the electromagnetic scattering of transverse magnetic (TM) waves impinging on a dimer of dielectric subwavelength scatterers. Our work provides a novel analytical method, based on amplitude weighted coefficients to describe the role of strong coupling in the molding of the total scattered field. The obtained results rev...

In this paper, we present a rigorous analytical and numerical method to evaluate the scattering of a plane electromagnetic wave by an infinite, perfectly conducting elliptic cylinder parallel to a non-perfectly re- flecting plane surface. The analytical solution is based on the spectral domain method and the plane- wave expansion of the elliptic cy...

The purpose of a circle packing procedure is to fill up a predefined, geometrical, closed contour with a maximum finite number of circles. The subject has received considerable attention in pure and applied sciences and has proved to be highly effective in connection with many a problem in logistics and technology. The well-known Apollonian circle...

The experimental data observation confirms the existence of two different populations in liquid water.

This work aimed to prove the feasibility of realizing an automatic non-invasive methodology to estimate the dielectric properties in-vivo of a generic human tissue and to create both a permittivity and a conductivity map in the microwave frequency range from 1 to 10 GHz.

We demonstrate that exploiting the cylindrical geometry of optical fibers allows for the ignition of helical-shaped plasma filaments.

Skin cancer (SC) is one of the most prevalent cancers worldwide. Clinical evaluation of skin lesions is necessary to assess the characteristics of the disease; however, it is limited by long timelines and variety in interpretation. As early and accurate diagnosis of SC is crucial to increase patient survival rates, machine-learning (ML) and deep-le...

Introduction: The incidence of melanoma increased considerably in recent decades, representing a significant public health problem. We aimed to evaluate the ability of non-specialists for the preliminary screening of skin lesions to identify melanoma-suspect lesions. Materials and Methods: A medical student and a dermatologist specialist examined t...

Medical images play an important role in medical diagnosis and treatment. Oncologists analyze images to determine the different characteristics of deadly diseases, plan the therapy, and observe the evolution of the disease. The objective of this paper is to propose a method for the detection of brain tumors. Brain tumors are identified from Magneti...

Hepatocellular carcinoma (HCC) is the most common primary liver cancer worldwide. Early diagnosis is crucial to improve management and provide survival benefits to patients with HCC. Liver biopsy coupled to histopathology remains the “gold standard”. Visual inspection of biopsy images is a crucial examination to identify tissue and cellular alterat...

Introduction. Hepatocellular carcinoma (HCC) is the most common primary liver cancer worldwide. Early diagnosis is crucial to improve management and provide survival benefits to patients with HCC. Liver biopsy coupled to histopathology remains the “gold standard”. Visual inspection of biopsy images is a crucial examination to identify tissue and ce...

The presentation is available on the YouTube channel bit.ly/videofrezza, at the following link: https://www.youtube.com/watch?v=UVhLTE76RDg

Machine learning (ML) is an interdisciplinary sector in the subset of artificial intelligence (AI) that creates systems to set up logical connections using algorithms, and thus offers predictions for complex data analysis. In the present review, an up-to-date summary of the current state of the art regarding ML and AI implementation for thyroid nod...

Manipulation and enhancement of nonlinear optical phenomena at the nanoscale with all-dielectric metasurfaces act as a perfect choice when explored with their plasmonic counterparts. The advantages of dielectric metasurface are reduced dissipative losses, large resonant enhancement, large mode volumes, and the presence of strong bulk light-matter i...

The temperature-dependent Goos-H¨anchen shift for the air-metal interface is explored in detail.We have described the initial observation of Goos-H¨anchen shift for an electromagnetic wave thrown back from the air-metal interface, when the shift becomes a function of temperature due to the optical properties of the metal which depend upon temperatu...

In this work, we propose a heuristic methodology using this hydration model as a base to realize an automatic and non-invasive procedure to estimate an ad-hoc map of the complex dielectric permittivity of a generic human tissue in the frequency range of microwaves based on their solid and water content, particularly useful in medical applications w...

We have measured the dielectric permittivity of pure water and aqueous chlorides solutions in the range 0.2-1.5THz. Considered the relaxation spectral function as the weighted sum of two independent single-parameter Debye functions [1] we have been able to drastically reduce the number of the parameters used in the fit. The experimental data in the...

This publisher’s note contains a correction to Opt. Lett. 47, 1 (2022)10.1364/OL.445321.

Dielectric metasurfaces have emerged as a promising alternative to their plasmonic counterparts due to lower ohmic losses, which hinder sensing applications and nonlinear frequency conversion, and their larger flexibility to shape the emission pattern in the visible regime. To date, the computational cost of full-wave numerical simulations has forc...

The scattering and absorption of light by small particles is a fundamental issue in electromagnetic (EM) theory, which is applied in surface plasmonics, Surface-Enhanced Raman Scattering (SERS), Optical Tweezers (OT). When the wavelength ~ sphere radius, need to use Mie theory to calculate the E field. A fast and accurate method to calculate the fi...

A work authored by various Professors from "La Sapienza" University of Rome in which some parallels are drawn between some current Economics dynamics and some characteristic scenarios in different branches of Engineering

This report shows a comparative outlook into different complex engineering dynamical systems subject to shocks and their similarities with the economy trends in Italy after the shock due to the COVID-19 pandemic.

The aim of this work is to propose a heuristic method, effective and easy to adopt, to estimate the complex dielectric permittivity of human tissues in the frequency range of microwaves and, in particular, at 2.45 GHz only on the base of their solid and water content. In this way it could be possible to realize an ad hoc dielectric mapping useful f...

A theoretical study of the temperature-dependent Goos-Hänchen shift is presented

With recently developed software called "Smuthi", a linear space-limited model is constructed in an all-dielectric metasurface made of AlGaAs nanocylinders on aluminium oxide substrate, this structure has been demonstrated to support very strong nonlinear optical effects such as second-harmonic generation (SHG) with efficiency around 10-4 at magnet...

Since the beginning of the COVID-19 outbreak, one of the main focuses worldwide has been to collect data on cases and deaths in the widest collaborative innovation to better understand the epidemic spread and keep its evolution under control. Under an “Open Innovation in Science” approach, researchers can contribute to producing new scientific know...

In this paper, we develop a simple technique to identify material texture from far, by using polarization-resolved imaging. Such a technique can be easily implemented into industrial environments, where fast and cheap sensors are required. The technique has been applied to both isotropic references (Teflon bar) and anisotropic samples (wood). By st...

Use of electromagnetic fields in the food industry for food inspection as well as sterilization and drying is increasing. To develop such applications, the knowledge of the dielectric properties of food is fundamental. In the literature, there is scarcity of data on dielectric properties of powdered foods, with reported values which are usually at...

An analysis of multiple scattering by two Perfect Electric Conducting (PEC) spheres using translation Addition Theorem (AT) for spherical vector wave functions is presented. Specifically, the Cruzan formalism is used to represent the AT for spherical harmonics, which introduces the translation coefficients for transformation of spherical harmonics...

We experimentally and numerically study the ignition of helical-shaped plasma filaments in standard optical fibers. Femtosecond pulses with megawatt peak power with proper off-axis and tilted coupling in the fiber core produce plasma skew rays. These last for distances as long as 1000 wavelengths thanks to a combination of linear waveguiding and th...

An analysis of multiple scattering by two Perfect Electric Conducting (PEC) sphere using translation Addition Theorem (AT) for spherical vector wave equation is presented. Specifically, Cruzan formalism is used to represent the AT for spherical harmonics, which introduced translation coefficients for transformation of spherical harmonic from one co...

Polarization measurements improve the imaging contrast by using various samples (wood, shinning steel, unpolished plastic). For better explanations of the micro-and macro-structures and basic characteristics of the materials, we perform Mueller matrix imaging on various samples, expressed by the characteristic features of the 3 × 3 Mueller matrix e...