Search results for " Telecom"

showing 10 items of 1269 documents

Modeling and Mitigating Errors in Belief Propagation for Distributed Detection

2021

We study the behavior of the belief-propagation (BP) algorithm affected by erroneous data exchange in a wireless sensor network (WSN). The WSN conducts a distributed multidimensional hypothesis test over binary random variables. The joint statistical behavior of the sensor observations is modeled by a Markov random field whose parameters are used to build the BP messages exchanged between the sensing nodes. Through linearization of the BP message-update rule, we analyze the behavior of the resulting erroneous decision variables and derive closed-form relationships that describe the impact of stochastic errors on the performance of the BP algorithm. We then develop a decentralized distribute…

hajautetut järjestelmätFOS: Computer and information sciencesfactor graphsComputer scienceComputer Science - Information TheoryBinary number02 engineering and technologycommunication errorsBelief propagationcomputation errorslangaton tiedonsiirtooptimointiLinearizationalgoritmit0202 electrical engineering electronic engineering information engineeringlikelihood-ratio testmessage-passing algorithmsElectrical and Electronic EngineeringStatistical hypothesis testingdistributed systemsMarkov random fieldsignaalinkäsittelyInformation Theory (cs.IT)linear data-fusionsensoriverkot020206 networking & telecommunicationscooperative communicationsData exchange020201 artificial intelligence & image processingblind signal processingRandom variableWireless sensor networkAlgorithm
researchProduct

Restoration and Enhancement of Historical Stereo Photos

2021

Restoration of digital visual media acquired from repositories of historical photographic and cinematographic material is of key importance for the preservation, study and transmission of the legacy of past cultures to the coming generations. In this paper, a fully automatic approach to the digital restoration of historical stereo photographs is proposed, referred to as Stacked Median Restoration plus (SMR+). The approach exploits the content redundancy in stereo pairs for detecting and fixing scratches, dust, dirt spots and many other defects in the original images, as well as improving contrast and illumination. This is done by estimating the optical flow between the images, and using it …

image denoisingComputer sciencemedia_common.quotation_subjectNoise reductionComputer applications to medicine. Medical informaticsR858-859.7ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISIONOptical flow02 engineering and technologyimage restorationArticleoptical flowgradient filteringPhotography0202 electrical engineering electronic engineering information engineeringRedundancy (engineering)historical photosContrast (vision)Radiology Nuclear Medicine and imagingComputer visionimage enhancementElectrical and Electronic EngineeringTR1-1050stereo matchingImage restorationmedia_commonSettore ING-INF/05 - Sistemi Di Elaborazione Delle Informazioniguided supersamplingImage fusionSettore INF/01 - Informaticabusiness.industry020206 networking & telecommunicationsSupersamplingQA75.5-76.95stacked medianComputer Graphics and Computer-Aided DesignTransmission (telecommunications)Electronic computers. Computer science020201 artificial intelligence & image processingComputer Vision and Pattern RecognitionArtificial intelligencebusinessimage denoising image restoration image enhancement stereo matching optical flow gradient filtering stacked median guided supersampling historical photosJournal of Imaging
researchProduct

Moving RTS/CTS to the frequency domain: an efficient contention scheme for 802.11ax networks

2019

In this paper, we propose a contention mechanism based on the execution of multiple contention rounds in the frequency domain (ReCHo), which is designed to offer high throughput performance and robustness with respect to imperfect carrier sensing. The main idea is using narrow tones as signalling messages for performing channel access contentions and allowing the Access Point (AP) to echo these signals, in order to extend the sensing capabilities to all the stations associated to the AP. In particular, we refer to the emerging IEEE 802.11ax standard, showing how our scheme can boost performance of random access with respect to the current version of IEEE 802.11ax OFDMA Back-Off (OBO), even …

imperfect sensingHidden node problemSettore ING-INF/03 - TelecomunicazioniOrthogonal frequency-division multiplexingComputer sciencebusiness.industryMechanism based020206 networking & telecommunications02 engineering and technologySignallingFrequency-domain signallingRobustness (computer science)020204 information systemsFrequency domainTelecommunications link0202 electrical engineering electronic engineering information engineeringfrequency-domain signalling; IEEE 802.11ax; imperfect sensing; random access contentionrandom access contentionbusinessIEEE 802.11axRandom accessComputer network
researchProduct

'Good to Repeat': Making Random Access Near-Optimal with Repeated Contentions

2020

Recent advances on WLAN technology have been focused mostly on boosting network capacity by means of a more efficient and flexible physical layer. A new concept is required at MAC level to exploit fully the new capabilities of the PHY layer. In this article, we propose a contention mechanism based on Repeated Contentions (ReCo) in frequency domain. It provides a simple-to-configure, robust and short-term fair algorithm for the random contention component of the MAC protocol. The throughput efficiency of ReCo is not sensitive to the number of contending stations, so that ReCo does not require adaptive tuning of the access parameters for performance optimization. Efficiency and robustness is …

imperfect sensingbusiness.industryOrthogonal frequency-division multiplexingComputer scienceSettore ING-INF/03 - TelecomunicazioniApplied MathematicsComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSPhysical layer020206 networking & telecommunicationsThroughput02 engineering and technologyIEEE 802.11ax; random access contention; frequency-domain signalling; imperfect sensingComputer Science ApplicationsPHYfrequency-domain signalling0202 electrical engineering electronic engineering information engineeringfrequency-domain signalingWirelessrandom access contentionSettore ICAR/19 - RestauroElectrical and Electronic EngineeringbusinessRandom accessIEEE 802.11axComputer network
researchProduct

Le tecniche investigative nel contrasto ai traffici di migranti, stupefacenti e sigarette

2019

The paper is aimed at analysing investigative techniques used in the fight against trafficking of migrants, drugs and tobaccos at national as well as at European level

interception of telecommunications Undercover operationProcedural instrumentEIOSettore IUS/16 - Diritto Processuale Penalemigrants drugtobacco
researchProduct

An Efficient Implementation of Parallel Parametric HRTF Models for Binaural Sound Synthesis in Mobile Multimedia

2020

The extended use of mobile multimedia devices in applications like gaming, 3D video and audio reproduction, immersive teleconferencing, or virtual and augmented reality, is demanding efficient algorithms and methodologies. All these applications require real-time spatial audio engines with the capability of dealing with intensive signal processing operations while facing a number of constraints related to computational cost, latency and energy consumption. Most mobile multimedia devices include a Graphics Processing Unit (GPU) that is primarily used to accelerate video processing tasks, providing high computational capabilities due to its inherent parallel architecture. This paper describes…

interpolation.General Computer Scienceparallel filtersComputer scienceGPUGpuGraphics processing unitLatency (audio)Parametric model02 engineering and technologycomputer.software_genre030507 speech-language pathology & audiology03 medical and health sciencesSoftware portabilityHRTF modeling0202 electrical engineering electronic engineering information engineeringGeneral Materials ScienceMultimediaparametric modelGeneral EngineeringTeleconferenceBinaural synthesis020206 networking & telecommunicationsVideo processingEnergy consumptioninterpolationInterpolationHrtf modelingScalabilityParallel filtersElectrónicaAugmented realitylcsh:Electrical engineering. Electronics. Nuclear engineering0305 other medical sciencelcsh:TK1-9971Mobile devicecomputerIEEE Access
researchProduct

Sistema di posizionamento geo-spaziale cooperativo operante con sistemi di navigazione globale satellitare e reti di telecomunicazione wireless, rela…

2010

kalman filters gps posizionamento cooperativoSettore ING-INF/03 - Telecomunicazioni
researchProduct

ARIANNA: pAth Recognition for Indoor Assisted NavigatioN with Augmented perception

2013

ARIANNA stands for pAth Recognition for Indoor Assisted Navigation with Augmented perception. It is a flexible and low cost navigation system for vi- sually impaired people. Arianna permits to navigate colored paths painted or sticked on the floor revealing their directions through vibrational feedback on commercial smartphones.

laneSettore ING-INF/04 - AutomaticaSettore ING-INF/03 - Telecomunicazioninavigation systempathblindvisualvibrationnavigation system; blind; lane; path; visual; vibration
researchProduct

THE MAIN PORTAL OF THE CATHEDRAL OF MONREALE: FIRST GEOMETRIC ANALYSIS AND INTERPRETIVE ASSESSMENT OF ARCHITECTURAL FEATURES

2017

Abstract. Nowadays, 3D documentation of architectural assets is becoming a demanding task for the valorisation of Cultural Heritage especially after a restoration project. The 3D documentation can be used for detailed analysis of specific elements, for monitoring the state of conservation and for valorisation actions. The paper describes the results of the 3D close-range photogrammetry survey of the main portal of the Cathedral of Monreale (Palermo, Italy). The Cathedral is one the most important monumental complexes in Sicily that, for its high historical and artistic importance has been inscribed on UNESCO’s World Heritage List since 2015. The main portal of the Cathedral has been recentl…

lcsh:Applied optics. PhotonicsEngineeringArchitectural engineeringGeometric analysis3d model02 engineering and technologylcsh:TechnologyCivil engineeringDocumentation0202 electrical engineering electronic engineering information engineeringCultural Heritage Restoration Photogrammetry 3D survey 3D Modelling Monumental Portallcsh:Tbusiness.industrylcsh:TA1501-1820020206 networking & telecommunicationsCultural heritagePhotogrammetryWork (electrical)lcsh:TA1-2040World heritage020201 artificial intelligence & image processinglcsh:Engineering (General). Civil engineering (General)businessInscribed figureSettore ICAR/06 - Topografia E Cartografia
researchProduct

Glottal Source Features for Automatic Speech-Based Depression Assessment

2017

Depression is one of the most prominent mental disorders, with an increasing rate that makes it the fourth cause of disability worldwide. The field of automated depression assessment has emerged to aid clinicians in the form of a decision support system. Such a system could assist as a pre-screening tool, or even for monitoring high risk populations. Related work most commonly involves multimodal approaches, typically combining audio and visual signals to identify depression presence and/or severity. The current study explores categorical assessment of depression using audio features alone. Specifically, since depression-related vocal characteristics impact the glottal source signal, we exa…

machine learningComputer scienceSpeech recognitionglottal source0202 electrical engineering electronic engineering information engineeringAutomatic speechPhase Distortion Deviation020206 networking & telecommunications020201 artificial intelligence & image processing02 engineering and technologybi-nary classificationDepression (differential diagnoses)Interspeech 2017
researchProduct