Search results for " FS"

showing 10 items of 42 documents

Rateless Codes Performance Analysis in Correlated Channel Model for GEO Free Space Optics Downlinks

2012

Settore ING-INF/03 - TelecomunicazioniFree Space Optics (FSO) technologies for satellite communications offer several advantages: wide bandwidth high rate capability immunity to electromagnetic interference and small equipment size. Thus they are suitable for inter-satellite links deep space communications and also for high data rate ground-to-satellite/satellite-to-ground communications. Nevertheless FSO links suffer impairments that cause power signal degradation at the receiver. Scattering and absorption cause power signal attenuations predictable by suitable deterministic models. Optical turbulence causes random irradiance fluctuations which can generate signal fading events and can thereby only be predicted by statistical models. Attenuation and fading events can corrupt FSO links and so it would be recommended to add mitigation error codes on the communication link. FSO channel can be described as an erasure channel: fading events can cause erasure errors. We have identified in rateless codes (RCs) a suitable solution to be employed in FSO links. RCs do not need feedback and they add a redundant coding on the source data that allows the receiver to recover the whole payload despite erasure errors. We implemented two different of rateless codes: Luby Transform (LT) and Raptor. We analyzed their performances on a simulated turbulent GEO FSO downlink (1 Gbps - OOK modulation) at a 106 μm wavelength and for different values of zenith angles. Assuming a plane-wave propagation and employing Hufnagel-Valley we modeled the downlink using: 1) a temporal correlated channel model based on Gamma-Gamma probability distribution and 2) an irradiance covariance function that we converted on a time function using Taylor frozen eddies hypothesis. Our new channel model is able to simulate irradiance fluctuations at different turbulence conditions as it will be shown in the full paper. We will also report performance results of LT and Raptor codes at overhead range varying between 0 and 50% and for different values of source packets.Settore ING-INF/01 - Elettronica
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Fading mitigation coding techniques for space to ground free space optical communications

2014

Settore ING-INF/03 - TelecomunicazioniSpace-to-Ground FSO links time-series rateless codefading mitigationSettore ING-INF/02 - Campi ElettromagneticiOptical Wireless CommunicationSettore ING-INF/01 - Elettronica
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Il corpo comunicativo. Fotografia come narrazione in Dorothea Lange

2022

In this article I explore Lange's life and work through the lens of her illness

Settore L-ART/06 - Cinema Fotografia E TelevisionePhotography art FSA Dorothea Lange reportage autopathography
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Fundamental investigation on the mechanical behavior of weld seams

The solid state welding processes allow joints free from defects with reduced residual stresses and low distortion. However, such processes are generally characterized by a complex mechanical junction because of the particular material flow. Therefore, the design and optimization of the processes in which the solid bonding phenomenon occurs are difficult and requires a large number of tests. The purpose of this research is the description on the mechanical behavior of welded seams obtained through the friction stir welding (FSW) and linear friction welding (LFW) processes by analyzing the same phenomenon that occurs in both metallurgical processes, named the solid bonding phenomenon. The ai…

Solid bonding LFW FSWSettore ING-IND/16 - Tecnologie E Sistemi Di Lavorazione
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Fading mitigation coding techniques for space to ground free space optical communications (Euro Med Telco 2014)

2014

In this manuscript, a Geostationary satellite-toground Free Space Optics (FSO) downlink channel model has been implemented, which is able to predict temporal irradiance fluctuations caused by scintillation at a wide range of turbulence conditions and for different values of the zenith angle. In order to mitigate fading events that occur in FSO communications, we have also tested the performance of three different families of Rateless Codes (Luby Transform, Raptor and RaptorQ) into our model and found that RaptorQ is the best candidate to mitigate errors in FSO links.

Space-to- Ground FSO linkSettore ING-INF/03 - Telecomunicazionifading mitigationrateless codeSettore ING-INF/02 - Campi ElettromagneticiOptical Wireless Communicationtime-serieSettore ING-INF/01 - Elettronica
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Du nouveau sur les fusarioses du concombre : Fusarium oxysporum f.sp. radicis-cucumerinum (FORC) isolé pour la première fois en France

2000

National audience

[SDV.BV.PEP] Life Sciences [q-bio]/Vegetal Biology/Phytopathology and phytopharmacyComputingMilieux_MISCELLANEOUSFUSARIUM OXYSPORUM FSP RADICIS-CUCUMERINUM[SDV.BV.PEP]Life Sciences [q-bio]/Vegetal Biology/Phytopathology and phytopharmacy
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Predictores emocionales y de personalidad que infl uyen en la aparición de las quejas somáticas en niños y en adultos

2019

Personality and emotional factors may be contributing to the emergence of somatic complaints. The purpose of this study was to analyse the combined contribution of emotional awareness, moods and personality to somatic complaints in children and adults. Method: Participants were 1,476 children (M= 9.90 years, SD= 1.27, 52.10% girls) and 940 adults (M= 32.30 years, SD= 11.62, 64% women) who were administered self-reports. Analysis was performed using fuzzy qualitative comparative analysis (fsQCA), an analytical technique that enables in-depth analysis of how a series of causal conditions contribute to a given outcome. Results: Emotional awareness, moods and personality account for 59% of high…

emotional awarenesspersonalitymoodSomatic complaintspersonalidadmodelos fsQCfsQCA modelsestados emocionalesconciencia emocionalquejas somáticas
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FLUMO: FLexible Underwater MOdem

2019

The last years have seen a growing interest in underwater acoustic communications because of its applications in marine research, oceanography, marine commercial operations, the offshore oil industry and defense. High-speed communication in the underwater acoustic channel has been challenging because of limited bandwidth, extended multipath, refractive properties of the medium, severe fading, rapid time variation and large Doppler shifts. In this paper, we show an implementation of a flexible Software-Defined Acoustic (SDA) underwater modem, where modulation parameters are completely tunable to optimize performance. In particular, we develop the system architecture following two key ideas. …

extended multipathSDAOrthogonal frequency-division multiplexingComputer sciencemarine commercial operationsUnderwater; acoustic ; software defined ; modem; JANUS; SDA; FSK; RedPitaya; WatermarkSettore ING-INF/01 - ElettronicaacousticFSKmodulate signalsDemodulationcontrolled testbedsUnderwaterunderwater acoustic channelOFDMFrequency-shift keyingFLUMOunderwater acoustic communicationsBandwidth (signal processing)Frequency shift keyingflexible Software-Definedoffshore oil industrysoftware definedRedPitayaflexible underwater MOdemmodulated signalsmodulation parameterstunable systemrefractive propertiesMultipath propagationStandardssystem architectureDoppler shiftsunderwater acoustic communicationhigh-speed communicationflexible systemElectronic engineeringDoppler shiftFadingoceanographymodemSettore ING-INF/03 - Telecomunicazionirapid time variationField programmable gate arraysmarine researchmodemsJANUSWatermarkSystems architectureUnderwater
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Effect of ovarian stimulation with recombinant LH/ FSH, recombinant FSH and human menopausal gonadotrophin (hMG) in reducing apoptosis rate in cumulu…

2013

medicine.medical_specialtybiologybusiness.industryObstetrics and GynecologyStimulationlaw.inventionRecombinant fshEndocrinologyReproductive MedicinelawApoptosisInternal medicineHMG-CoA reductasebiology.proteinmedicineRecombinant DNAovarian stimulation apoptosis cumulus cells ICSISettore BIO/06 - Anatomia Comparata E CitologiaMenotropinsbusinessFertility and Sterility
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“Coupling interfaces for communication transceivers over power lines”

2010

power line communication medium voltage cables fsk transreceivers
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