Search results for " parametric"
showing 10 items of 122 documents
Demonstration of polarization pulling in a fiber-optical parametric amplifier
2012
International audience; We report the experimental demonstration of all-optical polarization pulling of an initially polarization-scrambled signal using a fiber-optical parametric amplifier. Nonlinear polarization pulling has been achieved for both the signal and idler with 25 dB gain.
Temporal coherence in mirrorless optical parametric oscillators
2012
International audience; One of the unique features of mirrorless optical parametric oscillators based on counterpropagating three-wave interactions is the narrow spectral width of the wave generated in the backward direction. In this work, we in- vestigate experimentally and numerically the influence that a strong phase modulation in the pump has on the spectral bandwidths of the parametric waves and on the efficiency of the nonlinear interaction. The effects of group-velocity mismatch and group-velocity dispersion are elucidated. In particular, it is shown that the substan- tial increase in temporal coherence of the backward-generated wave can be obtained even for pumping with a temporally…
Experiments and theory of tunable broadband parametric gain in photonic crystal fibers
2006
International audience
3D Tools for CH Documentation
2020
The research focuses on the digital Computer Assisted Restoration procedures to guide the measure of integration of an artefact, innovating and implementing traditional research methods. Non-invasive 3D Digitalization techniques with high-performance devices allow the generation of applications for high-resolution visualization of three-dimensional environments with the possibility of navigating, analyzing and consulting virtual models in real time. The innovative application of 3D digital technologies has demonstrated that the integrated use of the new technology can be a useful tool to improve the entire process of collecting, storing and consulting information and data related to diagnos…
Architettura e second digital turn, l’evoluzione degli strumenti informatici e il progetto
2021
La condizione digitale che ha gradualmente ibridato le nostre esistenze, trasformando atomi in bit, si è oggi cementificata sulla nostra società, arricchendone la postmodernità e determinando una nuova liquidità acuitasi con l’avvento di internet. Un momento storico segnato da una nuova maturità del digitale, evidente nel nostro diverso rapporto con i dati, e nella diffusione di metodi di machine learning avanzato, che promettono una nuova capacità di comprensione della complessità contemporanea e nel frattempo contribuiscono alla propagazione dell’apparato tecnico sul mondo. Questi cambiamenti, tanto profondi da toccare la nostra cultura, stanno modificando il nostro modo di interpretare e…
Restituzioni omografiche di finte cupole: la cupola di Santa Maria dei Rimedi a Palermo
2016
Nel vasto repertorio siciliano delle prospettive solide, un ruolo di spicco è ricoperto da un esempio unico di realizzazione di finta prospettiva di cupola sferica su copertura ad arco ribassato, ricavata sull’incrocio del transetto con la navata centrale nella chiesa di Santa Maria dei Rimedi a Palermo. L’unicità di quest’opera sta nella geometria reale della cupola ribassata. Infatti gli esempi più diffusi di finte cupole in Sicilia sono realizzati su soffitti piani lignei o in calcestruzzo. In Appendice 1 si potrà consultare il repertorio delle finte cupole esistenti in Sicilia per la cui stesura ci si è avvalsi degli studi condotti dall’architetto Giuseppe Ingaglio nell’ambito della sua…
Elastīgais parametriskais modelis izdzīvošanas datiem ar konkurējošiem riskiem
2015
Konkurējošie riski ir izplatīta parādība izdzīvošanas analīzē. Tie rodas, kad subjekts atrodas vairāku savstarpēji izslēdzošu notikumu riska zonā. Populārākā metode, pētot šāda veida datus, ir Deivida Koksa semi-parametriskā modeļa izmantošana. Darbā ir aplūkots alternatīvais variants izdzīvošanas datiem ar konkurējošiem riskiem – elastīgais parametriskais modelis, kas sniedz gludus novērtējumus galvenajiem raksturlielumiem – konkrēto cēloņu riskam un kumulatīvo biežumu funkcijai. Turklāt, izmantojot šo modeli, ir viegli iekļaut no laika atkarīgus ietekmējošos mainīgos. Darbā tiek aprakstīta konkurējošo risku elastīgā parametriskā modeļa būtība, un metode ir salīdzināta ar Koksa modeli. Ir …
Models Used for Measuring Customer Engagement
2013
The purpose of the paper is to define and measure the customer engagement as a forming element of the relationship marketing theory. In the first part of the paper, the authors review the marketing literature regarding the concept of customer engagement and summarize the main models for measuring it. One probability model (Pareto/NBD model) and one parametric model (RFM model) specific for the customer acquisition phase are theoretically detailed. The second part of the paper is an application of the RFM model; the authors demonstrate that there is no statistical significant variation within the clusters formed on two different data sets (training and test set) if the cluster centroids of t…
Locked-in Syndrome and 18F-fluorodeoxyglucose-positron Emission Tomography/Computed Tomography: Observations from a Case of Basilar Artery Thrombosis
2018
We report the case of a 59-year-old male patient suffering from locked-in syndrome (LIS) following basilar artery thrombosis despite an attempt of thrombolysis. Neurological examination showed quadriplegia and aphonia and a state of coma requiring mechanical ventilation was diagnosed. The use of 18F-fluorodeoxyglucose (18F-FDG)-positron emission tomography (PET) allowed to detect a normal 18F-FDG uptake in the main cerebral cortical areas and a significant reduction of 18F-FDG uptake in both cerebellar hemispheres, compatible with a functional deafferentation, helping confirming the clinical suspicion of LIS. The diagnosis of LIS, according to literature, is based on the clinical assessment…
A boosting approach for prostate cancer detection using multi-parametric MRI
2015
International audience; Prostate cancer has been reported as the second most frequently diagnosed men cancers in the world. In the last decades, new imaging techniques based on MRI have been developed in order to improve the diagnosis task of radiologists. In practise, diagnosis can be affected by multiple factors reducing the chance to detect potential lesions. Computer-aided detection and computer-aided diagnosis have been designed to answer to these needs and provide help to radiologists in their daily duties. In this study, we proposed an automatic method to detect prostate cancer from a per voxel manner using 3T multi-parametric Magnetic Resonance Imaging (MRI) and a gradient boosting …