Search results for "EOF"

EOFs for gap filling in multivariate air quality data: a FDA approach

2010

Missing values are a common concern in spatiotemporal data sets. During recent years a great number of methods have been developed for gap filling. One of the emerging approaches is based on the Empirical Orthogonal Function (EOF) methodology, applied mainly on raw and univariate data sets presenting irregular missing patterns. In this paper EOF is carried out on a multivariate space-time data set, related to concentrations of pollutants recorded at different sites, after denoising raw data by FDA approach. Some performance indicators are computed on simulated incomplete data sets with also long gaps in order to show that the EOF reconstruction appears to be an improved procedure especially…

A crustal seismic profile across Sicily

2011

Abstract A crustal reflection seismic profile, more than 100 km long, was recorded across central Sicily, from the Tyrrhenian shore to the Sicily Channel, to understand the deep structures and the collision mechanisms between Europe and Africa and the subsequent geodynamic evolution. The profile was acquired using explosive sources and 240 active channels recorded by a Sercel 408-XL, 24 bits A/D converter, with a 12 km spread and a 24-fold coverage. The data were processed following a non-conventional procedure in order to preserve the relative amplitudes of the reflections and to better investigate the Sicily deep structures down to the Moho. The main highlighted structures are the dramati…

Multi-disciplinary analysis to construct a crustal model of the Sicily Channel using geological and geophysical techniques (data): impacts on geologi…

2023

To understand the dynamics of crustal deformation and earthquakes in active orogenic systems, it is essential to have a detailed view of the lithospheric structures in three dimensions (3D). Several studies in the literature explain how 3D visualization can enable the recognition of tectonic structures or to be able to establish connections between intraplate volcanoes (Wu et al., 2016; Lei & Zhao, 2016; Tan et al., 2019). This work aims to define and discretize a 1D-velocity model of the Sicily Channel; create a detailed 3D lithospheric model of the Sicily Channel using a multidisciplinary approach to evaluate the geological hazard elements that affect the Iblean foreland integrating bathy…

Functional Principal Component Analysis for the explorative analysis of multisite-multivariate air pollution time series with long gaps

2013

The knowledge of the urban air quality represents the first step to face air pollution issues. For the last decades many cities can rely on a network of monitoring stations recording concentration values for the main pollutants. This paper focuses on functional principal component analysis (FPCA) to investigate multiple pollutant datasets measured over time at multiple sites within a given urban area. Our purpose is to extend what has been proposed in the literature to data that are multisite and multivariate at the same time. The approach results to be effective to highlight some relevant statistical features of the time series, giving the opportunity to identify significant pollutants and…

Sicily’s fold–thrust belt and slab roll-back: the SI.RI.PRO. seismic crustal transect

2016

Sicily is a thick orogenic wedge formed by (1) the foreland (African) and its Sicilian orogen and (2) the thick-skinned, Calabrian–Peloritani wedge. The crust under central Sicily, from the Tyrrhenian margin to the coastline of the Sicily Channel, has been investigated by the multidisciplinary (SI.RI.PRO.) research project. The project dealt with the nature and thickness of the crust and depth and geometry of the Moho, which is essential in formulating subduction models and improving the knowledge of African and Tyrrhenian–European lithospheres. The results resolve features such as (1) the main orogenic wedge, (2) the very steep, NW–SE-trending regional monocline suggesting inflection of th…

Results of isolated posterolateral corner reconstruction

2010

Abstract Background Isolated posterolateral corner (PLC) tears are relatively rare events. Various surgical techniques to treat posterolateral knee instability have been described; because surgical results are linked to cruciate reconstructions it has been difficult to date to define whether one surgical procedure has better prognosis than another. The goal of this study is to determine the clinical outcome of PLC reconstruction following fibular-based technique. Materials and methods We retrospectively evaluated a case series of patients who received isolated PLC reconstruction between March 2005 and January 2007. Ten patients were surgically treated for isolated injuries and were availabl…

Integrated Geophysical Investigations at the Greek Kamarina Site (Southern Sicily, Italy)

2018

Kamarina, located in southern Sicily (Italy), was an important Greek colony since its foundation in the sixth century BC. Archaeological excavations, carried out since the twentieth century, uncovered only limited portions of the site so far. Despite the importance of the Greek colony, the presence of remarkable buildings that archaeologists expected to bring to light has not found fully correspondence in the archaeological excavations. Consequently, the integrated geophysical prospection carried out in the study area is aimed to support and address the future archaeological investigations. After the photographic and thermographic survey obtained by an unmanned aerial vehicle, we performed …

Robert Lepage - Il teatro ad orologeria

2009

Review of the Hydrogen Evolution Reaction—A Basic Approach

2021

An increasing emphasis on energy storage has resulted in a surge of R&D efforts into producing catalyst materials for the hydrogen evolution reaction (HER) with emphasis on decreasing the usage of platinum group metals (PGMs). Alkaline water electrolysis holds promise for satisfying future energy storage demands, however the intrinsic potential of this technology is impeded by sluggish reaction kinetics. Here, we summarize the latest efforts within alkaline HER electrocatalyst design, where these efforts are divided between three catalyst design strategies inspired by the three prevailing theories describing the pH-dependence of the HER activity. Modifying the electronic structure of a …

Atmospheric correction algorithm for POLDER data. Case study: DAISEX 1999 campaign

2006

RESUMEN Este artículo presenta un algoritmo para corregir los efectos de la atmósfera de la reflectividad multiangulare hiperespectral de POLDER, prestando especial atención al efecto de los aerosoles. Los datos fueron adquiridos durante la campaña DAISEX-99 de la Agencia Espacial Europea. El algoritmo está basado en la inversión de la reflectividad medida en dos pasos. Primero, se invierte la reflectividad de POLDER para determinar los tres parámetros de la función de distribución de la reflectividad bidireccional de la superficie (BRDF). Estos valores son los datos de entrada de la superficie para el segundo paso. En este segundo paso, invertimos de nuevo la reflectividad para obtener tre…