Search results for "Optical"
showing 10 items of 7671 documents
Connection Of System Measuring Voltages And Currents Of High Voltage Power Line To A Microcomputer By Optical Fibre Link
1986
The prototype of equipment for service of the measuring units of power high voltage line is presented. That system is composed of the transmitter /with A/D conversion/, optical fibre data link and receiver feeding the output into the microcomputer. The application of this equipment in the automatic protection system protecting the power network against short-circuit is described.
Combined Analysis of OFDM-UWB Transmission in Hybrid Wireless-Optical Access Networks
2009
[EN] The hybrid wireless-optical transmission of ultra-wideband signals employing orthogonal frequency-division multiplexing modulation (OFDM) ultra-wideband (UWB) as defined in the ECMA-368 standard is experimentally analyzed in this letter. The OFDM-UWB signals provide 400 Mb/s per user at optical distances from 5 to 50 km on standard single-mode fiber (SSMF). The analysis includes the wireless radiation from 0 to 3 m after optical transmission. The results indicate a maximum error-vector-magnitude degradation of 2.5 dB measured at 1.5-m radio after 50-km SSMF optical transmission for the first two UWB channels. This degradation translates to 1-m maximum wireless-reach penalty.
Analytical model for high-strength concrete columns with square cross-section
2008
In the present paper a mechanical model to predict the compressive response of high strength short concrete columns with square cross-section confined by transverse steel is presented. The model allows one to estimate the equivalent confinement pressures exercised by transverse steel during the loading process taking into account of the interaction of the stirrups with the inner core both in the plane of the stirrups and in the space between two successive stirrups. The lateral pressure distributions at hoop levels are obtained by using a simple model of elastic beam on elastic medium simulating the interaction between stirrups and concrete core, including yielding of steel stirrups and dam…
A mobile robot for vigilance tasks improved with a new robust and low cost communications system immune to attacks with EMI noise
2006
This work pretends to develop a robot for vigilance tasks that are able to tolerate diverse kinds of attacks and be able to operate in environments with elevated electromagnetic noise, being even immune to sabotage provoked by means of high electromagnetic fields. A new CAN based communications system that interconnects the different devices that compose the mobile robot has been developed to achieve this goal. The system is based on a shielded communications hub, that interconnects diverse nodes by means of CAN. On the other hand, the point to point communication between each node and the hub is carried out by means of economic optical fiber. With this approach all robot devices are connec…
A Methodology for the Design of MOS Current-Mode Logic Circuits
2010
In this paper, a design methodology for the minimization of various performance metrics of MOS Current-Mode Logic (MCML) circuits is described. In particular, it allows to minimize the delay under a given power consumption, the power consumption under a given delay and the power-delay product. Design solutions can be evaluated graphically or by simple and effective automatic procedures implemented within the MATLAB environment. The methodology exploits the novel concepts of crossing-point current and crossing-point capacitance. A useful feature of it is that it provides the designer with useful insights into the dependence of the performance metrics on design variables and fan-out capacitan…
<title>Optical models used for the study of laser beam</title>
2007
The study of the laser beam is based on optical models, therefore optical models are suited as a tool for study, implement and evaluate the characteristics of an unfocused laser beam. The analysis of the optical models shows the characteristics of pulse and continuous laser beam and the influence over the quality of the industrial process.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Packet loss recovery in an indoor Free Space Optics link using rateless codes
2014
Free Space Optics (FSO) systems present some important advantages if compared to Radio Frequency links, but they can be affected by several impairments that degrade the link quality and availability. In particular, due to temporary interruptions of the line-of-sight condition between the transmitter and the receiver, packet loss can occur during data transmission. In this work, we present an indoor Free Space Optics link, in which we have systematically generated interruptions of the beam. We demonstrate how the application of the most recent rateless codes, i.e., RaptorQ codes, can strongly improve the link quality by reducing packet loss. In particular, results show that the Packet Error …
Design of a configurable multispectral imaging system based on an AOTF.
2011
In this paper, we present a configurable multispectral imaging system based on an acousto-optic tunable filter (AOTF). Typically, AOTFs are used to filter a single wavelength at a time, but thanks to the use of a versatile sweeping frequency generator implemented with a direct digital synthesizer, the imager may capture a configurable spectral range. Experimental results show a good spectral and imaging response of the system for spectral bandwidth up to a 50 nm.
Optimized design of high power density EMI filters for power electronic converters
2016
Nowadays, power density of power converters and related EMI filters is gaining more and more attention. This severely impacts on the design constraints in several application domains. A conventional design of the EMI filter does not guarantee the selection of components/configuration leading to the best power density. For this reason, an optimized design procedure of discrete EMI filters in terms of power density is proposed in this paper. It is based on a previously developed rule-based design procedure, introducing here additional features to obtain a more effective optimization of EMI filter's power density. The proposed approach has been validated in terms of EMI filter's performance an…
Journeys from quantum optics to quantum technology
2017
Sir Peter Knight is a pioneer in quantum optics which has now grown to an important branch of modern physics to study the foundations and applications of quantum physics. He is leading an effort to develop new technologies from quantum mechanics. In this collection of essays, we recall the time we were working with him as a postdoc or a PhD student and look at how the time with him has influenced our research.