Search results for " Communication"

Asynchronously switched control of discrete impulsive switched systems with time delays

2013

This paper is concerned with the stabilization problem for a class of uncertain discrete impulsive switched delay systems under asynchronous switching. The so-called asynchronous switching means that the switches between the candidate controllers and system modes are asynchronous. By using the average dwell time (ADT) approach, sufficient conditions for the existence of an asynchronously switched controller is derived such that the resulting closed-loop system is exponentially stable. The desired controller gains and the admissible switching signals are obtained in terms of a set of matrix inequalities. A numerical example is given to illustrate the effectiveness of the proposed method.

Performance comparison of residual related algorithms for ToA positioning in wireless terrestrial and sensor networks

2009

©2009 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE." Article also available from publisher: http://dx.doi.org/10.1109/WIRELESSVITAE.2009.5172462 Time of Arrival (ToA) is a popular technique for terrestrial positioning. This paper presents a comparison of ToA based residual related positioning algorithms in wireless terrestrial and sensor networks in both long range outdoor and short range indoor environments. Us…

Indoor free space optics link under the weak turbulence regime: Measurements and model validation

2015

In this study, the authors present the measurements performed on a free space optics (FSO) communications link using an indoor atmospheric chamber. In particular, the authors have generated several different optical turbulence conditions, demonstrating how even the weak turbulence regime can strongly affect the FSO link performance. The authors have carried out an in-depth analysis of the data collected during the measurements, and calculated the turbulence strength (i.e. scintillation index and Rytov variance) and the important performance metrics (i.e. the Q-factor and bit error rate) to evaluate the FSO link quality. Moreover, the authors have tested, for the first time, an appositely de…

Time trends of technology mediated communication with friends among bullied and not bullied children in four Nordic countries between 2001 and 2010

2016

Background Friends are important in childhood and adolescence, especially to bullied children. Technology mediated communication (TMC) could be used both to develop and maintain friendship. The present study examined (1) trends in the use of TMC with friends between 2001 and 2010; (2) possible differences between bullied and not bullied children and (3) differences between children with few close friends and children with several close friends. Methods Data were obtained from three waves of the serial cross-sectional Health Behaviour in School-Aged Children survey conducted in Denmark, Finland, Iceland and Sweden during 2001/2002, 2005/2006 and 2009/2010. The total sample consisted of 65 95…

A simple timestamping data acquisition system for ToF-ERDA

2015

A new data acquisition system, ToF-DAQ, has been developed for a ToF-ERDA telescope and other ToF-E and ToF-ToF measurement systems. ToF-DAQ combines an analogue electronics front-end to asynchronous time stamped data acquisition by means of a FPGA device. Coincidences are sought solely in software based on the timestamps. Timestamping offers more options for data analysis as coincidence events can be built also in offline analysis. The system utilises a National Instruments R-series FPGA device and a Windows PC as a host computer. Both the FPGA code and the host software were developed using the National Instruments LabVIEW graphical programming environment. Up to eight NIM ADCs can be han…

A Lightweight Network Discovery Algorithm for Resource-constrained IoT Devices

2019

Although quite simple, existing protocols for the IoT suffer from the inflexibility of centralized infrastructures and require several configuration stages. The implementation of these protocols is often prohibitive on resource-constrained devices. In this work, we propose a distributed lightweight implementation of network discovery for simple IoT devices. Our approach is based on the exchange of symbolic executable code among nodes. Based on this abstraction, we propose an algorithm that makes even IoT resource-constrained nodes able to construct the network topology graph incrementally and without any a priori information about device positioning and presence. The minimal set of executab…

Sensory adaptation of antennae and sex pheromone-mediated flight behavior in male oriental fruit moths (Leptidoptera: Tortricidae) after prolonged ex…

2013

Sensory adaptation has been measured in the antennae of male Grapholita molesta (Busck) after 15 min of exposure to its main pheromone compound (Z)-8-dodecen-1-yl acetate (Z8-12:OAc) at the aerial concentration of 1 ng/m(3) measured in orchards treated with pheromone for mating disruption. Exposing males to this aerial concentration of Z8-12:OAc for 15 min, however, had only a small effect on their ability to orientate by flight to virgin calling females in a flight tunnel. Experiments were undertaken to determine if exposure to the main pheromone compound in combination with the two biologically active minor compounds of this species, (E)-8-dodecen-1-yl acetate (E8-12:OAc) and (Z)-8-dodece…

Mixed Harmonic Elimination Control for a Single-Phase 9 Level Grid-Connected Inverter

2018

The power quality requirements are increasingly stringent, due to the continuous growth of devices connected to the grid that introduce harmonics. These devices include DC to AC energy conversion systems, i.e. grid connected inverters. The design, control and operation of these systems must take into account the rules of interconnection to the electricity grid. To improve the quality of the output waveform of the grid-connected inverter, Multilevel Converters (MC) with selective harmonic elimination modulation technique can be used. This paper presents a single-phase nine level grid-connected inverter with DC/DC input stages. The obtained switching angles for THD minimization are independen…

Tourism and Communication on the Internet: the Case of the Italian Wine and Food Roads Web Sites Quality

2007

The role of ICT, eWOM and guest characteristics in loyalty

2019

Purpose This study aims to examine how technologies contribute to consumer loyalty in the tourist industry. To achieve this objective, information and communication technology (ICT) development and electronic word-of-mouth (eWOM) are analysed to explore their direct and indirect effects on satisfaction and loyalty dimensions. The moderating role of customer characteristics (personal and experience-related variables) is also considered to study the complex relationship between satisfaction and loyalty. Design/methodology/approach A quantitative study based on a questionnaire structured was developed. The survey was conducted with 386 guests from Spanish hotels. SEM methodology is applied to…