Andrea Randazzo’s research while affiliated with Università degli Studi di Genova and other places

What is this page?


This page lists works of an author who doesn't have a ResearchGate profile or hasn't added the works to their profile yet. It is automatically generated from public (personal) data to further our legitimate goal of comprehensive and accurate scientific recordkeeping. If you are this author and want this page removed, please let us know.

Publications (277)


Microwave Imaging of Partially Known Targets Through a Mild Data-Driven Approach
  • Conference Paper

September 2024

·

4 Reads

·

·

·

A. Randazzo


Erratum to “Improved Chebyshev Spectral Method Modeling for Vector Radiative Transfer in Atmospheric Propagation”

September 2024

·

2 Reads

IEEE Transactions on Antennas and Propagation

In the above article [1] , several errors were introduced during the production.



FIGURE 3. Schematic of the grid considered for acquiring dielectric measurements over the Carasau dough samples.
FIGURE 5. Distribution of the relative complex permittivity for the rectangular sample with 46% (a), 50% (b), and 54% í µí±¾ % (c), and average complex permittivity (real -d, and imaginary -e) for the rectangular sample with respect to í µí±¾ % variation at 5.8 GHz.
FIGURE 12. Representation of the simulation environment with the simple 5.8 GHz patch antenna (the same model is used for all the layouts). Parameters: Sp = 35 mm, Wp = 19.54 mm, Lp = 15.15 mm, xfp = 3 mm, hp = 2 mm (substrate thickness), d = 10 mm.
FIGURE 20. Summary of the simulated and measured results taking account for shift of magnitude and phase of the S11 due to the variation of water content W%, antenna-sheet distance d, and sheet thickness hs.
Preliminary Design and Test of a Microwave Inline Moisture Sensor for the Carasau Bread Industry
  • Article
  • Full-text available

July 2024

·

135 Reads

·

1 Citation

IEEE Open Journal of Antennas and Propagation

Within the framework of the recent agri-food technological advancement, the design and validation of a methodology for the water content estimation in the Carasau bread manufacturing process is herein presented. Following a thorough evaluation of the dough dielectric properties, a suitable antenna layout has been selected, pointing out the advantages in the choice of a contactless narrow-band antenna in comparison to wide-band and dual-band ones. The presented simulated results are then validated using a prototype sensor and an ad hoc measurement system to confirm the antenna ability to discriminate among doughs with different water content. In addition, an accurate analysis of possible sources of misinterpretation of the results is presented. INDEX TERMS dielectric properties, moisture sensor, Carasau bread, patch antenna, food engineering

Download

Quantitative Inversion of Multiantenna Ground-Penetrating Radar Data with Modeling Error Correction Based on Long Short-Term Memory Cells

June 2024

·

30 Reads

Quantitative inversion of GPR data opens the door to precise characterization of underground environments. However, in order to make the inverse scattering problem solution easier from a computational viewpoint, simplifying assumptions are often applied, i.e., two-dimensional approximations or the consideration of idealized field probes and electromagnetic sources. These assumptions usually produce modeling errors, which can degrade the dielectric reconstruction results considerably. In this article, a processing step based on long short-term memory cells is proposed for the first time to correct the modeling error in a multiantenna GPR setting. In particular, time-domain GPR data are fed into a neural network trained with couples of finite-difference time-domain simulations, where a set of sample targets are simulated in both realistic and idealized configurations. Once trained, the neural network outputs an approximation of multiantenna GPR data as they are collected by an ideal two-dimensional measurement setup. The inversion of the processed data is then accomplished by means of a regularizing Newton-based nonlinear scheme with variable exponent Lebesgue space formulation. A numerical study has been conducted to assess the capabilities of the proposed inversion methodology. The results indicate the possibility of effectively compensating for modeling error in the considered test cases.


Fig. 6 Reference and estimated Stokes parameters for í µí±” = 0.8 at the TOA level. í µí¼ 1 = 1, í µí¼ˆ 0 = 1, í µí¼™ í µí±œí µí±í µí± = 0.
Fig. 7 Reference and estimated Stokes parameters for í µí±” = 0.8 at the BOA level. í µí¼ 1 = 1, í µí¼ˆ 0 = 1, í µí¼™ í µí±œí µí±í µí± = 0.
Fig. 8 Computational times against the optical thickness í µí¼ 1 for the ground albedo í µí±” = 0,0.25,0.8 when í µí¼ˆ 0 = 0.1.
Improved Chebyshev Spectral Method Modeling for Vector Radiative Transfer in Atmospheric Propagation

May 2024

·

18 Reads

·

1 Citation

IEEE Transactions on Antennas and Propagation

An improved spectral coefficient method based on Chebyshev polynomials of the second kind is employed to solve the vector radiative transfer equation under the assumption of parallel-plane atmosphere and Rayleigh scattering. The solver is extended to consider a Lambertian surface at the bottom of the atmosphere. The computational properties of the proposed algorithm are analyzed and the validity of the implemented method is tested against a publicly available benchmark dataset.



Application of a mild data-driven technique to Lippmann-Schwinger inverse scattering in variable-exponent Lebesgue spaces for microwave imaging

April 2024

·

69 Reads

·

3 Citations

A mild data-driven approach for microwave imaging is considered in this paper. In particular, the developed technique relies upon the use of a Newton-type inversion scheme in variable-exponent Lebesgue spaces, which has been modified by including a data-driven operator to enforce the available a-priori information about the class of targets to be investigated. In this way, the performance of the method is improved, and the problems related to the possible convergence to local minima are mitigated. The effectiveness of the approach has been evaluated through numerical simulations involving the detection of defects inside (partially) known objects, showing good results.



Citations (40)


... To address point (a), many techniques have been proposed in the scientific literature to solve the nonlinear inverse scattering problem [15][16][17][18][19][20]. Most of them, due to the high computational cost of solving this problem, are based on two-dimensional (2D) formulations [21][22][23][24]. ...

Reference:

Quantitative Inversion of Multiantenna Ground-Penetrating Radar Data with Modeling Error Correction Based on Long Short-Term Memory Cells
Application of a mild data-driven technique to Lippmann-Schwinger inverse scattering in variable-exponent Lebesgue spaces for microwave imaging

... With further development, MPI has the potential to provide a non-radioactive, deep-tissue 'magnetic tracer' imaging complement to existing modalities. Besides MPI, MNPs have also been used as contrast agents in MRI and newer modalities such as microwave imaging for cost-effective breast cancer detection [135] or to modulate hyperthermia of deep-seated tumors [136]. However, the working principle here relies on contrast generation within an anatomic image which differs fundamentally from the magnetic 'tracer' principles that is the focus of this chapter. ...

Feasibility Analysis of Theranostic Magnetic Scaffolds for Microwave Monitoring of Hyperthermia Treatment of Bone Tumors

IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology

... As another interesting approach for solving ISPs that has received a lot of attention in the last year, we refer to various deep learning-based methods; see, e.g., [20][21][22][23][24] for an incomplete list of recent works focusing on this direction. Some results for microwave imaging data for medical applications have been reported in [25][26][27]. Numerical results of this approach appear promising, although the mathematical foundation of deep learning is still to be investigated. ...

Microwave Medical Imaging of the Human Neck using a Neural-Networks-Based Inversion Procedure: A Phantom Study
  • Citing Conference Paper
  • March 2023

... These issues motivate the use of suitable processing techniques to extract target information from GPR data [7]. Several GPR processing techniques have been developed in the past few decades, and they can be roughly subdivided into two main classes: qualitative approaches (i.e., aimed at obtaining only some information about targets, such as their position, shape, and size) [8][9][10], and quantitative methods (i.e., whose goal is a complete electromagnetic characterization of the targets of interest) [11][12][13]. ...

Microwave Imaging of Mixed Metallic–Dielectric Configurations via a Finite Element-Based Variable Exponent Approach

... In this work, a microwave imaging approach is proposed for the monitoring of the cooldown process. Indeed, the dielectric properties of powder commonly used in PBF printers, i.e., PA12, have been found to have a nonnegligible dependance upon the temperature when sintered [4]. Consequently, an inverse-scattering approach has been developed for the reconstruction of the distribution of the dielectric properties inside the printing chamber. ...

In-situ microwave tomography for parts’ cooldown monitoring in powder bed fusion of polymers

Additive Manufacturing

... Indeed, to monitor the drug release or the temperature increase during HT, the changes must be detectable by external antennas, hence the MW signal variation due to the endpoint (e.g., release of the drug cargo or a given ) must be measurable with existing system [46]. This apparently obvious problem demands for new, focused and oriented design of nanosystems meant to be used for EM-based cancer therapeutics, while requiring preliminary MW signal propagation analysis in differential scenario, as done in [47], and experimental tests in controlled laboratory setting to determine the feasibility of theranostics approach of this kind. ...

Feasibility Analysis of Theranostic Magnetic Scaffolds for Microwave Monitoring of Hyperthermia Treatment of Bone Tumors

... For time-domain-induced electromagnetic signals, long short-term memory (LSTM) passes signals step by step via the time series, utilizing gate mechanisms to selectively retain time-domain signal features carrying crucial electrical media information [35,36]. This optimizes feature extraction from time-domain signals, enhancing the neural network model's predictive capability in electromagnetic signal inversion. ...

An LSTM Based Strategy for Data and Model Calibration in Subsurface Electromagnetic Imaging
  • Citing Conference Paper
  • December 2022

... To address point (a), many techniques have been proposed in the scientific literature to solve the nonlinear inverse scattering problem [15][16][17][18][19][20]. Most of them, due to the high computational cost of solving this problem, are based on two-dimensional (2D) formulations [21][22][23][24]. ...

Microwave-Based Subsurface Characterization through A Combined Finite Element and Variable Exponent Spaces Technique

Sensors

... Carasau bread is made from re-milled semolina of durum wheat, sea salt, natural yeast, and de-chlorinated drinking water [13]. The production chain includes kneading, leavening, sheeting, and baking stages, which will be better explained in Section II. ...

Designing a Microwave Moisture Content Sensor for Carasau Bread: A Feasibility Study
  • Citing Conference Paper
  • March 2022

... The measured scattered electrical fields were used to reconstruct two-dimensional images solving the inverse scattering problem. The model detected significant changes in the size of the spinal cord and suggested that further studies on the human neck should be considered in the future to validate the capabilities of similar approaches using the DL model [142]. Similarly, Costanzo. ...

Initial Experimental Tests of an ANN-Based Microwave Imaging Technique for Neck Diagnostics

IEEE Microwave and Wireless Components Letters