170,081 research outputs found
SPM/XPM-induced intensity distortion in WDM systems
No full textIn high bit rate multiwavelength optical transmission systems, self-phase (SPM) and cross-phase modulation (XPM) interact with fiber chromatic dispersion producing intensity distortion on tghe transmitted signals. In this paper, starting from a generalization of Wang and Petermann [1], wghich approximately predicts the effect of phase-to-intensity modulation (PM/IM) conversion in purely linear fibers, we introduce a new analytical model of thge intensity distortions induced by SPM and XPM. The model well captures the distributed generation of SPM (XPM) by accounting for the PM/IM conversion due to the infinitesimal SPM (XPM) components generated in each infinitesimal segment along the fiber
Generalized Raman Scattering Model and Its Application to Closed-Form GN Model Expressions Beyond the C+L Band
No full textWe derive a wide-band approximation of the stimulated Raman scattering formula and show its application to Gaussian noise (GN) model closed-form expressions for transmissions even beyond the C+L band
Carlo Bononi, Incoronazione della Vergine.
No full text1616–1620, oil on canvas, 280 cm in diameter, Ferrara, Basilica of Santa Maria in Vado: a) painting (sampling points are indicated by asterisks, *); b) damage due to biodegradation (verso); c) craquelures network; d) lacerations, deformations, and gaps corresponding to the cloth stitching (recto). Details of the damage are reported on the side. Reprinted from http://www.museoinvita.it/lincoronazione-della-vergine-di-carlo-bononi/ under a CC BY license, with permission from “MuseoinVita” biannual journal, original copyright 2018.</p
GC-C-IRMS and 1H-NMR characterization of synthetic bis(methylthio)methane in truffle flavorings
No full textBis(methyl-thio)methane (BMTM), the molecule which provides “white truffle-like” flavor was characterized by physico-chemical methods. Analysis by GC-C-IRMS of eight samples of synthetic BMTM from various origins, ten samples purchased on the Italian flavoring market and twenty seasoning purchased on the Italian market, allowed the investigation of the global δ 13C values. Analysis by 1H NMR of two samples of both a synthetic standard and a “white truffle-like” flavor consisting of synthetic BMTM as the principal component allowed the investigation of the isotopic distribution of 13C/12C ratio in two characteristic sites of this molecule.
An easily produced extract using methanol-d4 allowed the identification and the characterization of BMTM available in “white truffle-like” flavorings distributed on the specialized flavorings market as synthetic BMTM supported in olive oil
Intrusion Detection for Secure Clustering and Routing in Mobile Multi-hop Wireless Networks
No full textIntrusion detection and secure routing schemes have been proposed for increasing security and reliability in critical wireless scenarios. In this paper we present an integrated secure routing system based on Intrusion Detection Systems (IDS) and Statistically Unique and Cryptographically Verifiable (SUCV) identifiers. The proposed IDS has been used for the support of secure Ad Hoc On Demand Distance Vector (AODV) routing, named IDS-based Secure AODV (IS-AODV), in wireless ad hoc and vehicular network scenarios. Our IDS is based on the detection of behavior anomalies on behalf of neighbor hosts, with passive reactions, aiming to create a cluster whose route paths will include only safe nodes, eventually. Simulation results show that the proposed IDS is effective in isolating misbehaving hosts, and it assists the AODV secure routing scheme to converge in finding safe end-to-end routes
Raman-aware enhanced GN-model to estimate the modulation format dependence of the SNR tilt in C+L band
No full textBy including the inter-channel stimulated Raman scattering in the enhanced Gaussian noise model we show that the modulation format has an impact on the Raman-induced tilt on the signal-to-noise ratio of ultra-wideband optical transmissions
Gain-shaped waterfilling is Quasi-optimal for Constant-pump Flattened-EDFA Submarine Links
No full textFor EDFA-amplified submarine links, we corroborate the results in1 by analytically deriving an approximate capacity-achieving distribution where power is allocated inversely to the EDFA gain
Incremento della sensibilità del metodo "GenElute Plant Genomic DNA Miniprep" nel rilevamento di OGM
No full textLa sperimentazione oggetto della presente nota si inquadra nell'ambito di una ricerca più ampia, volta alla verifica dei dati di sensibilità delle tecniche attualmente consigliate nella rilevazione di DNA transgenico. Il protocollo di estrazione del DNA da sfarinati GenElute Plant Genomic DNA Miniprep è stato modificato al fine di consentire, in casi di particolare necessità, di evidenziare la presenza di DNA transgenico in quantità inferiori all'1%
Modeling Nonlinear Interference with Sparse Raman-Tilt Equalization
No full textWe investigate the impact of accumulated stimulated Raman scattering (SRS) on the nonlinear interference (NLI) variance due to sparse gain-tilt equalization along the optical link. We propose simple modifications to analytical models available in the literature, such as the Gaussian noise (GN) or the enhanced Gaussian noise (EGN) models, for reliable NLI estimation in the presence of accumulated SRS. We additionally generalize closed-form expressions of the NLI variance in a GN framework to the new scenario. We validate the models through split-step Fourier method simulations showing the importance of including the gain-tilt equalization period in the model to preserve the accuracy. The proposed model is then used to provide insights on the interplay between the NLI and accumulated SRS
The Enhanced Gaussian Noise Model Extended to Polarization-Dependent Loss
No full textWe show how to extend the enhanced Gaussian noise (EGN) model to account for polarization-dependent loss (PDL) of optical devices placed along a fiber-optic link. We provide a comprehensive theory highlighting the relationships between the time, frequency, and polarization domains in the presence of fiber nonlinear Kerr effect and amplified spontaneous emission. We double-check the new model with split-step Fourier method (SSFM) simulations showing very good accuracy. The model can be efficiently exploited to estimate low values of outage probabilities induced by PDL with computational times orders of magnitude faster than the SSFM, thus opening new opportunities in the design of optical communication links
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