30 research outputs found

    An ab-initio approach to describe coherent and non-coherent exciton dynamics

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    The use of ultra-short laser pulses to pump and probe materials activates a wealth of processes which involve the coherent and non coherent dynamics of interacting electrons out of equilibrium. Non equilibrium (NEQ) many body perturbation theory (MBPT) offers an equation of motion for the density-matrix of the system which well describes both coherent and non coherent processes. In the non correlated case there is a clear relation between these two regimes and the matrix elements of the density-matrix. The same is not true for the correlated case, where the potential binding of electrons and holes in excitonic states need to be considered. In the present work we discuss how NEQ-MBPT can be used to describe the dynamics of both coherent and non-coherent excitons in the low density regime. The approach presented is well suited for an ab initio implementation

    Architettura basata su SAP BW per l’adeguamento del sistema contabile di un Istituto finanziario ai principi IAS

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    Questo lavoro Ăš stato redatto con la finalitĂ  di dimostrare, tramite una reale implementazione in un contesto aziendale, i vantaggi dell’utilizzo di SAP BW come strumento di Data Warehousing. Tale argomento viene trattato adottando un approccio “dal generale al particolare”: si descrivono inizialmente gli elementi cruciali di un sistema di Data Warehousing, poi si passa all’analisi delle caratteristiche di SAP BW e infine si propone un esempio concreto di un progetto con BW al centro dell’architettura complessiva. Tale esempio concreto Ăš stato estrapolato da un’esperienza diretta in un progetto rilevante condotto da una societĂ  di consulenza (Accenture S.p.A.) all’interno di un istituto finanziario. La realizzazione del sistema ha previsto un utilizzo estensivo di SAP BW, non solo come strumento di reporting direzionale, ma anche come “accentratore di dati storici” e, dunque, come sorgente dati per altri sistemi (ad es. SAP/R3 o SAP BA) nei casi necessari Il progetto si Ăš collocato nell’ambito di grossi cambiamenti di tale istituto che hanno richiesto interventi necessari; tra questi, l’adeguamento ai principi contabili IAS risulta il piĂč rilevante

    InProC: Industry and Product/Service Code Classification

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    Determining industry and product/service codes for a company is an important real-world task and is typically very expensive as it involves manual curation of data about the companies. Building an AI agent that can predict these codes automatically can significantly help reduce costs, and eliminate human biases and errors. However, unavailability of labeled datasets as well as the need for high precision results within the financial domain makes this a challenging problem. In this work, we propose a hierarchical multi-class industry code classifier with a targeted multi-label product/service code classifier leveraging advances in unsupervised representation learning techniques. We demonstrate how a high quality industry and product/service code classification system can be built using extremely limited labeled dataset. We evaluate our approach on a dataset of more than 20,000 companies and achieved a classification accuracy of more than 92\%. Additionally, we also compared our approach with a dataset of 350 manually labeled product/service codes provided by Subject Matter Experts (SMEs) and obtained an accuracy of more than 96\% resulting in real-life adoption within the financial domain

    The potential of eupraxia@sparc_lab for radiation based techniques

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    A proposal for building a Free Electron Laser, EuPRAXIA@SPARC_LAB, at the Laboratori Nazionali di Frascati, is at present under consideration. This FEL facility will provide a unique combination of a high brightness GeV-range electron beam generated in a X-band RF linac, a 0.5 PW-class laser system and the first FEL source driven by a plasma accelerator. The FEL will produce ultra-bright pulses, with up to 1012 photons/pulse, femtosecond timescale and wavelength down to 3 nm, which lies in the so called “water window”. The experimental activity will be focused on the realization of a plasma driven short wavelength FEL able to provide high-quality photons for a user beamline. In this paper, we describe the main classes of experiments that will be performed at the facility, including coherent diffraction imaging, soft X-ray absorption spectroscopy, Raman spectroscopy, Resonant Inelastic X-ray Scattering and photofragmentation measurements. These techniques will allow studying a variety of samples, both biological and inorganic, providing information about their structure and dynamical behavior. In this context, the possibility of inducing changes in samples via pump pulses leading to the stimulation of chemical reactions or the generation of coherent excitations would tremendously benefit from pulses in the soft X-ray region. High power synchronized optical lasers and a TeraHertz radiation source will indeed be made available for THz and pump–probe experiments and a split-and-delay station will allow performing XUV-XUV pump–probe experiments.Fil: Balerna, Antonella. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Bartocci, Samanta. UniversitĂ  degli studi di Sassari; ItaliaFil: Batignani, Giovanni. UniversitĂ  degli studi di Roma "La Sapienza"; ItaliaFil: Cianchi, Alessandro. Universita Tor Vergata; Italia. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Chiadroni, Enrica. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Coreno, Marcello. Istituto Nazionale Di Fisica Nucleare.; Italia. Istituto di Struttura della Materia; ItaliaFil: Cricenti, Antonio. Istituto di Struttura della Materia; ItaliaFil: Dabagov, Sultan. Istituto Nazionale Di Fisica Nucleare.; Italia. National Research Nuclear University; Rusia. Lebedev Physical Institute; RusiaFil: Di Cicco, Andrea. Universita Degli Di Camerino; ItaliaFil: Faiferri, Massimo. UniversitĂ  degli studi di Sassari; ItaliaFil: Ferrante, Carino. UniversitĂ  degli studi di Roma “La Sapienza”; Italia. Center for Life Nano Science @Sapienza; ItaliaFil: Ferrario, Massimo. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Fumero, Giuseppe. UniversitĂ  degli studi di Roma “La Sapienza”; ItaliaFil: Giannessi, Luca. Elettra-Sincrotrone Trieste; Italia. ENEA C.R. Frascati; ItaliaFil: Gunnella, Roberto. Universita Degli Di Camerino; ItaliaFil: Leani, Juan Jose. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto de FĂ­sica Enrique Gaviola. Universidad Nacional de CĂłrdoba. Instituto de FĂ­sica Enrique Gaviola; ArgentinaFil: Lupi, Stefano. UniversitĂ  degli studi di Roma “La Sapienza”; Italia. Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Roma La Sapienza; ItaliaFil: Macis, Salvatore. UniversitĂ  degli Studi di Roma Tor Vergata; Italia. Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Roma Tor Vergata; ItaliaFil: Manca, Rosa. UniversitĂ  degli studi di Sassari; ItaliaFil: Marcelli, Augusto. Istituto Nazionale Di Fisica Nucleare.; Italia. Consiglio Nazionale delle Ricerche; ItaliaFil: Masciovecchio, Claudio. Elettra-Sincrotrone Trieste; ItaliaFil: Minicucci, Marco. Universita Degli Di Camerino; ItaliaFil: Morante, Silvia. Universita Tor Vergata; Italia. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Perfetto, Enrico. Universita Tor Vergata; Italia. Consiglio Nazionale delle Ricerche; ItaliaFil: Petrarca, Massimo. UniversitĂ  degli studi di Roma "La Sapienza"; Italia. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Pusceddu, Fabrizio. UniversitĂ  degli studi di Sassari; ItaliaFil: Rezvani, Javad. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Robledo, JosĂ© Ignacio. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto de FĂ­sica Enrique Gaviola. Universidad Nacional de CĂłrdoba. Instituto de FĂ­sica Enrique Gaviola; ArgentinaFil: Rossi, Giancarlo. Centro Fermi—Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”; Italia. Istituto Nazionale Di Fisica Nucleare.; Italia. Universita Tor Vergata; ItaliaFil: Sanchez, Hector Jorge. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto de FĂ­sica Enrique Gaviola. Universidad Nacional de CĂłrdoba. Instituto de FĂ­sica Enrique Gaviola; ArgentinaFil: Scopigno, Tullio. Center for Life Nano Science @Sapienza; Italia. UniversitĂ  degli studi di Roma "La Sapienza"; ItaliaFil: Stefanucci, Gianluca. Universita Tor Vergata; Italia. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Stellato, Francesco. Universita Tor Vergata; Italia. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Trapananti, Angela. Universita Degli Di Camerino; ItaliaFil: Villa, Fabio. Istituto Nazionale Di Fisica Nucleare.; Itali

    Assessing the Maintenance Processes of a Software Organization: an Empirical Analysis of a Large Industrial Project

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    The use of statistical process control methods can determine the process capability of sustaining stable levels of variability, so that processes will yield predictable results. This enables to prepare achievable plans, meet cost estimates and scheduling commitments, and deliver required product functionality and quality with acceptable and reasonable reliability. We present initial results of applying statistical analysis methods to the maintenance processes of a software organization rated at the CMM level 3 that is currently planning the assessment to move to the CMM level 4. In particular, we present results from an empirical study conducted on the massive adaptive maintenance process of the organization. We analyzed the correlation between the maintenance size and productivity metrics. The resulting models allow to estimate the costs of a project conducted according to the adopted maintenance processes. Model performances on future observations were assessed by means of a cross validation which guarantees a nearly unbiased estimate of the prediction error. Data about the single phases of the process were also available, thus allowing to analyze the distribution of the effort among the phases and the causes of variations

    Role of Electrophysiology in the Early Diagnosis and Follow-Up of Diabetic Retinopathy

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    Retinopathy is a severe and common complication of diabetes, representing a leading cause of blindness among working-age people in developed countries. It is estimated that the number of people with diabetic retinopathy (DR) will increase from 126.6 million in 2011 to 191 million by 2030. The pathology seems to be characterized not only by the involvement of retinal microvessels but also by a real neuropathy of central nervous system, similar to what happens to the peripheral nerves, particularly affected by diabetes. The neurophysiological techniques help to assess retinal and nervous (optic tract) function. Electroretinography (ERG) and visual evoked potentials (VEP) allow a more detailed study of the visual function and of the possible effects that diabetes can have on the visual function. These techniques have an important role both in the clinic and in research: the central nervous system, in fact, has received much less attention than the peripheral one in the study of the complications of diabetes. These techniques are safe, repeatable, quick, and objective. In addition, both the ERG (especially the oscillatory potentials and the flicker-ERG) and VEP have proved to be successful tools for the early diagnosis of the disease and, potentially, for the ophthalmologic follow-up of diabetic patients
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