arXiv subjects

P. Bianchi

Publications and source records attributed to P. Bianchi.

10 recordsLinked to original sources

arXiv2022

Relationship between Climate and Famine from 1250 to 1350 in Central Italy

This study aims to present an overview of how climate change brought about by events such as earthquakes, volcanic eruptions, flares and variations in solar activity, etc. have characterized the area of central Italy, analyzing and comparing astronomical, geological, meteorological, seismological, historical and climatic data, taking as reference some specific locations in the period between 1250 and 1350. The ultimate goal is to understand how long-term climatic and geological events in this geographical area have changed the territory both from a natural and anthropic point of view, leading to highlight the occurrence of extreme events such as wave of plague of the period 1347-1351. The analysis is performed using a statistical-historical approach and particular attention is paid to minimize any effect due to the error in the event of a lack of data.

physics.ao-ph↗

arXiv2021

Stochastic optimization with momentum: convergence, fluctuations, and traps avoidance

In this paper, a general stochastic optimization procedure is studied, unifying several variants of the stochastic gradient descent such as, among others, the stochastic heavy ball method, the Stochastic Nesterov Accelerated Gradient algorithm (S-NAG), and the widely used Adam algorithm. The algorithm is seen as a noisy Euler discretization of a non-autonomous ordinary differential equation, recently introduced by Belotto da Silva and Gazeau, which is analyzed in depth. Assuming that the objective function is non-convex and differentiable, the stability and the almost sure convergence of the iterates to the set of critical points are established. A noteworthy special case is the convergence proof of S-NAG in a non-convex setting. Under some assumptions, the convergence rate is provided under the form of a Central Limit Theorem. Finally, the non-convergence of the algorithm to undesired critical points, such as local maxima or saddle points, is established. Here, the main ingredient is a new avoidance of traps result for non-autonomous settings, which is of independent interest.

math.OC↗

arXiv2021

New Astronomical, Meteorological and Geological Study of Montefiascone (VT)

In this work that continues the "NGICS - New Italian City Geological Study" a project of the Department of Climatology and Geology of TS Corporation Srl, we present the study relating to the Municipality of Montefiascone (VT). We analyzed 25 years of astronomical, geological, meteorological and climatic data, comparing them to verify the long-term trend of local variations in temperatures, detections, solar radiation and geological events, with the ultimate goal of understanding climate and geological changes a long term in this geographical area. The analysis is performed using a statistical approach and attention is used to minimize any effects caused by the error in case of lack of data.

astro-ph.IM↗

arXiv2020

Artificial neural networks for 3D cell shape recognition from confocal images

We present a dual-stage neural network architecture for analyzing fine shape details from microscopy recordings in 3D. The system, tested on red blood cells, uses training data from both healthy donors and patients with a congenital blood disease. Characteristic shape features are revealed from the spherical harmonics spectrum of each cell and are automatically processed to create a reproducible and unbiased shape recognition and classification for diagnostic and theragnostic use.

q-bio.QM↗

arXiv2019

New Astronomical, Meteorological and Geological Study of Pieve a Nievole (PT)

In this paper we present an analysis of the geological, meteorological and climatic data recorded in Pieve a Nievole (PT) over 24 years and using this data for the establishment of the research structure called "PAN.R.C. - Pieve a Nievole Research Center" and "NGICS - New study of geological and Italian city". These data are compared to check local variations, long term trends and correlation with maen annual temperature. The ultimate goal of this work is to understand long term climatic changes in this geographic area. The analysis is performed using a statistical approach and a particular care is used to minimize any effect due to prejudices in case of lack of data.

physics.ao-ph↗

arXiv2018

A New Level 3 Biosafety and Astrobiology Laboratory in Pieve a Nievole (PT)

We report our proposal for the establishment of a biocontainment and astrobiology laboratory in a strategic area of Pieve a Nievole (PT) at 28 mt above sea level - to face the lack of biological and astrobiological research centers and all the social, economic and cultural consequences that this project implicate. The structure will be built under the Horizon 2020 work program 2018-2020 - European Research Infrastructures (including e-Infrastructures), and will enable the development of major research project.

astro-ph.IM↗

arXiv2015

New Meteorological and Geological Study of Taviano (LE)

This paper contains the result of the elaboration of informations about Solar Irradiation, Geological, Meteorological and Climatic from the point of view of the quantitative data and social interaction recorded in Taviano (LE) over 24 years. These data are compared to check local variations, long term trends, and correlation with mean annual temperature. The ultimate goal of this work is to understand long term climatic changes in this geographic area. The classes of event considerated are hydrogeological phenomena, sun irradiation, seismic, volcanic, meteorological and climatological event. Only event occurred between 1990 and 2014 are considerated. The analysis is performed using a statistical approach. A particular care is used to minimize any effect due to prejudices in case of lack of data. Finally, we calculate the annual average from the monthly ones. Data on this paper don't come from a complete census of phenomena; they are considered enough representative of the accepted vulnerability level at the beginning of this study.

astro-ph.IM↗

arXiv2015

New Meteorological and Geological Study of Acquapendente (VT)

In this paper we present an analysis of the geological, meteorological and climatic data recorded in Acquapendente (VT) over 24 years. These data are compared to check local variations,long term trends, and correlation with maen annual temperature. The ultimate goal of this work is to understand logn term climatic changes in this geographic area. The analysis is performed using a statistical approach. From each long series of data calculate the hourly averages and that the monthly averages in order to reduce the fluctuations in the short time due to the day / night cycle. A particular care is used to minimize any effect due to prejudices in case of lack of data. Finally, we calculate the annual average from the monthly ones.

astro-ph.IM↗

arXiv2008

Asymptotic Independence in the Spectrum of the Gaussian Unitary Ensemble

Consider a $n \times n$ matrix from the Gaussian Unitary Ensemble (GUE). Given a finite collection of bounded disjoint real Borel sets $(Δ_{i,n},\ 1\leq i\leq p)$, properly rescaled, and eventually included in any neighbourhood of the support of Wigner's semi-circle law, we prove that the related counting measures $({\mathcal N}_n(Δ_{i,n}), 1\leq i\leq p)$, where ${\mathcal N}_n(Δ)$ represents the number of eigenvalues within $Δ$, are asymptotically independent as the size $n$ goes to infinity, $p$ being fixed. As a consequence, we prove that the largest and smallest eigenvalues, properly centered and rescaled, are asymptotically independent; we finally describe the fluctuations of the condition number of a matrix from the GUE.

math.PR↗

arXiv2008

Cooperative Spectrum Sensing Using Random Matrix Theory

In this paper, using tools from asymptotic random matrix theory, a new cooperative scheme for frequency band sensing is introduced for both AWGN and fading channels. Unlike previous works in the field, the new scheme does not require the knowledge of the noise statistics or its variance and is related to the behavior of the largest and smallest eigenvalue of random matrices. Remarkably, simulations show that the asymptotic claims hold even for a small number of observations (which makes it convenient for time-varying topologies), outperforming classical energy detection techniques.

cs.IT↗