Search results for "working"

Broadband Internet Access via Multi-Hop Wireless Mesh Networks: Design, Protocol and Experiments

2010

Published version of an article from the journal: Wireless Personal Communications. The original publication is available at Spingerlink. http://dx.doi.org/10.1007/s11277-009-9907-9 While bandwidth for Internet access in urban areas is steadily increasing in recent years, many rural areas are still suffering from the effect of the digital divide. This paper presents a broadband Internet access paradigm developed in the context of the ADHOCSYS project, which was financed by the European Commission under the 6th Framework Program Information and Society Technologies, within the strategic objective of Broadband for All. Aiming at providing reliable Internet access in rural and mountainous regi…

A Software Defined approach to the Internet of Things: From Wireless Sensor Networks to Network Operating Systems

Di recente il mondo delle reti di telecomunicazioni è stato caratterizzato dall’emergere del paradigma di Networking Software Defined (SDN). Grazie a questo approccio è possibile fornire un’interfaccia standard per lo sviluppo di software in grado di gestire i dispositivi di networking e i flussi di traffico che li attraversano, disaccoppiando il management della rete dal forwarding dei dati. Questa soluzione, di cui il protocollo di comunicazione OpenFlow è tra i maggiori esponenti, ha riscosso un notevole successo nelle reti cablate permettendo di superare il vendor lock-in e permettendo la gestione di dispositivi eterogenei tramite un unico punto di accesso logicamente centralizzato. …

SDN controllers security issues

2017

Software-Defined Networking (SDN) is essentially varying the way we design and manage networks, which makes a communication network programmable. In SDN, a logically centralized controller has straight control over the packet-handling functions of the network switches, using a standard, open API (Application Programming Interface) such as OpenFlow. OpenFlow is a broadly used protocol for software-defined networks (SDNs) that presents a new model in which the control plane is inattentive from the forwarding plane for the network devices. In SDN approach centralized entities called "controllers" perform like network operating systems run dissimilar applications that accomplish and control the…

Reliable Coverage with Circumferential WMSNs

2021

This work tackles the closed peripheral coverage issue. Such circumferential surveillance is essential in numerous realistic applications where the goal is to ensure rapid detection of any unauthorized entry/exit of the monitored area. To respond to these requirements, peripheral WMSNs can be rapidly deployed around areas of interest (e.g., temporary military camps, natural or nuclear disasters, etc.). While it seems simple, this solution raises two major challenging issues. First, checking whether the deployed peripheral WMSN forms a closed shape around the monitored region. That is, any object trying to leave or access this area must be instantaneously detected by at least one multimedia …

Positioning Error Prediction and Training Data Evaluation in RF Fingerprinting Method

2019

Radio Frequency (RF) fingerprinting-based localization has become a research interest due to its minimum hardware requirement and satisfiable positioning accuracy. However, despite the significant attention this topic has gained, most of the research focused on the calculation of position estimates. In this paper, we propose a simple and novel method that can be used as an indicator of fingerprinting positioning error. The method is based on cluster radius evaluation of multiple fingerprinting data during the test phase, which can be used by a Location Based Service (LBS) provider to predict the user position estimation accuracy. This method can be used effectively in real-time to predict t…

PROGETTO DI SMART WORKING DURANTE LA PANDEMIA DI COVID-19: SMART CO-WORKING PER LA RETE ASSISTENZIALE FRA PEDIATRI DI LIBERA SCELTA E UN CENTRO DI RI…

2021

Obiettivi La pandemia di COVID-19 ha modificato le strategie assistenziali in modo radicale. Le necessità di distanziamento sociale hanno condizionato l’accesso alle cure ospedaliere, con il rischio che i pazienti cronici, più vulnerabili, venissero gestiti con inadeguata interazione con le famiglie e i pediatri di famiglia (PdF), con gravi ritardi diagnostici e terapeutici. Metodi Un questionario con 10 domande sulla gestione dei pazienti con ipotiroidismo congenito (IC) è stato inviato ai PdF della regione Sicilia (Palermo, Agrigento, Trapani, Enna, Caltanissetta, Siracusa). Risultati Hanno risposto 55 PdF che seguono da 2 a 3 pazienti con IC, con prevalenza più elevata in aree ad alta en…

Modeling Networks of Probabilistic Memristors in SPICE

2021

Efficient simulation of stochastic memristors and their networks requires novel modeling approaches. Utilizing a master equation to find occupation probabilities of network states is a recent major departure from typical memristor modeling [Chaos, solitons fractals 142, 110385 (2021)]. In the present article we show how to implement such master equations in SPICE – a general purpose circuit simulation program. In the case studies we simulate the dynamics of acdriven probabilistic binary and multi-state memristors, and dc-driven networks of probabilistic binary and multi-state memristors. Our SPICE results are in perfect agreement with known analytical solutions. Examples of LTspice code are…

Study of a Novel High Permeability Ferrite Sheet Intended for Near Field Communication Systems

2019

The reduction of embedded portable devices involves a magnetic field interference problem when it integrates Near Field Communication (NFC) due to the presence of conductive surfaces such as ground planes, batteries or metallic enclosures. This contribution is focused on analyzing the ability of an innovative magnetic shielding based on flexible sintered ferrite sheets (FSFS) with the aim of improving the performance of that kind of systems. Thereby, a NFC emitter antenna is characterized when it is close to a conductive surface through an electromagnetic (EM) scanner. The EM scanner composed by a matrix of near field probes that make it possible to determine the effectiveness of the FSFS. …

Registration of arbitrary multi-view 3D acquisitions

2013

International audience; To register 3D meshes representing smooth surfaces we track the 3D digitization system using photogrammetric techniques and calibrations. We present an example by digitizing a 800 mm x 600 mm portion of a car door. To increase the tracking accuracy the 3D scanner is placed in a cubic frame of side 0.5 m covered with 78 targets. The target frame moves in a volume that is approximately 1100 mm x 850 mm x 900 mm, to digitize the area of interest. Using four cameras this target frame is tracked with of an accuracy of 0.03 mm spatially and 0.180 mrad angularly. A registration accuracy between 0.1 mm and 2 mm is reached. This method can be used for the registration of mesh…

Performance Analysis of M-DPSK Modulation over Fast-Hoyt Fading Channels under Non-Isotropic Scattering Conditions

2021

In this paper, we analyze the symbol error probability (SEP) performance of M-ary differential phase shift keying (M-DPSK) modulation schemes over frequency-flat fast-varying Hoyt multipath fading channels. Assuming general non-isotropic scattering conditions, we first derive a finite-range integral expression for the probability density function (PDF) of the phase difference between two non-isotropic Hoyt vectors perturbed by additive white Gaussian noise (AWGN). Based upon the theory of M-DPSK modulation and the obtained PDF formula, the SEP of M-DPSK and its corresponding asymptotic behavior in non-isotropic fast-Hoyt fading channels are derived. Specifically, a double semi-finite range …