Search results for "Propagation"
showing 10 items of 676 documents
Suppression law of quantum states in a 3D photonic fast Fourier transform chip
2015
The identification of phenomena able to pinpoint quantum interference is attracting large interest. Indeed, a generalization of the Hong–Ou–Mandel effect valid for any number of photons and optical modes would represent an important leap ahead both from a fundamental perspective and for practical applications, such as certification of photonic quantum devices, whose computational speedup is expected to depend critically on multi-particle interference. Quantum distinctive features have been predicted for many particles injected into multimode interferometers implementing the Fourier transform over the optical modes. Here we develop a scalable approach for the implementation of the fast Fouri…
The effect of body shape and gender on wireless Body Area Network on-body channels
2010
Technological advancements have made possible the emergence of Body Area Networks (BANs). There are numerous on-body channel characterizations in the literature performed on a phantom or a single human subject. In this paper, using multiple subjects, we consider the effect of body shape and gender on the on-body channel. A characterization of a narrowband on-body to on-body channel among different subjects is presented. The paper investigates the relationship between the propagation and the subject's physical characteristics. The investigation is performed at 2360 MHz; the new medical band undergoing FCC approval. Our results show that the path loss in women is less than that in men and the…
Use of standard and setup of non conventional techniques for the elimination of viruses associated with Fig Mosaic Disease (FMD) in fig germplasm (Fi…
2017
Abstract Ficus carica L. is considered one of the oldest fruit trees in the Mediterranean basin and is widely grown and harvested for the consumption of its fruits dry and fresh. This species is affected by different virus diseases, especially by Fig mosaic disease (FMD), for which Fig leaf mottle-associated virus 1 (FLMaV-1), Fig leaf mottle-associated virus 2 (FLMaV-2), Fig mild mottling-associated virus (FMMaV), Fig mosaic virus (FMV), Fig latent virus 1 (FLV-1), Fig badnavirus 1 (FBV-1) and Fig fleck-associated virus (FFkaV) are associated. FMD is the most widespread disorder of this species, which represents a threat and a constraint for healthy fig production and germplasm exchange. T…
Micropropagation of Citrus spp. by Organogenesis and Somatic Embryogenesis.
2013
Citrus spp., the largest fruit crops produced worldwide, are usually asexually propagated by cuttings or grafting onto seedling rootstocks. Most of Citrus genotypes are characterized by polyembryony due to the occurrence of adventive nucellar embryos, which lead to the production of true-to-type plants by seed germination. Tissue culture and micropropagation, in particular, are valuable alternatives to traditional propagation to obtain a high number of uniform and healthy plants in a short time and in a small space. Moreover, in vitro propagation provides a rapid system to multiply the progeny obtained by breeding programs, allows the use of monoembryonic and seedless genotypes as rootstock…
Obstructing propagation of interfering modes improves detection of guided waves in coated bone models
2014
Interference due to wave propagation in soft tissue that covers the bone is a major challenge to in vivo assessment of the fundamental flexural guided wave (FFGW) in bone. To improve signal-to-interference ratio (SIR) we propose to obstruct the propagation of interfering modes by locally deforming the coating by external mechanical compression. This approach was modeled by 2D finite-element transient domain (FEMTD) simulations in a fluid-coated (7 mm) solid plate (3 mm). The fluid layer mimics the soft tissue that covers the bone. A single emitter or a 6-element phased array excited ultrasound pulses at 50 kHz on the surface of the coating, and a receiver array was placed on the surface, 20…
Assessment of a geological model by surface wave analyses
2016
A set of horizontal to vertical spectral ratio (HVSR) and multichannel analysis of surface waves (MASW) measurements, carried out in the Altavilla Milicia (Sicily) area, is analyzed to test a geological model of the area. Statistical techniques have been used in different stages of the data analysis, to optimize the reliability of the information extracted from geophysical measurements. In particular, cluster analysis algorithms have been implemented to select the time windows of the microseismic signal to be used for calculating the spectral ratio H/V and to identify sets of spectral ratio peaks likely caused by the same underground structures. Using results of reflection seismic lines, ty…
Joint User Association and Dynamic Beam Operation for High Latitude Muti-beam LEO Satellites
2021
In Low Earth Orbit (LEO) satellites, which run in polar orbit, the area of overlap among beams becomes wider as the latitude of satellites increases, which leads to intolerable interference and extra energy consumption. To minimize the onboard power with QoS requirements, we propose an energy optimization model with considering power allocation, user association and dynamic beam ON/OFF operation jointly. Moreover, the frequent beam ON/OFF operations lead to the large number of user handovers, so handover cost is also considered in the model. The original problem is decomposed into two levels due to the high coupling of variables and the successive convex approximation is employed. A low com…
<title>Optical non-invasive monitoring of skin blood pulsations</title>
2005
Time resolved detection and analysis of the skin backscattered optical signals (remission photoplethysmography or PPG) provide rich information on skin blood volume pulsations and can serve for reliable cardiovascular assessment. The single- and multi-channel PPG concepts are discussed in this work. Simultaneous data flow from several body locations allows one to study the heartbeat pulse wave propagation in real time and evaluate the vascular resistance. Portable single-, dual- and four-channel PPG monitoring devices with special software have been designed for real-time data acquisition and processing. The clinical studies confirmed their potential in the monitoring of heart arrhythmias, …
A machine learning approach to determine airport asphalt concrete layer moduli using heavy weight deflectometer data
2021
An integrated approach based on machine learning and data augmentation techniques has been developed in order to predict the stiffness modulus of the asphalt concrete layer of an airport runway, from data acquired with a heavy weight deflectometer (HWD). The predictive model relies on a shallow neural network (SNN) trained with the results of a backcalculation, by means of a data augmentation method and can produce estimations of the stiffness modulus even at runway points not yet sampled. The Bayesian regularization algorithm was used for training of the feedforward backpropagation SNN, and a k-fold cross-validation procedure was implemented for a fair performance evaluation. The testing p…
Apertureless scanning near-field optical microscopy: a comparison between homodyne and heterodyne approaches
2006
International audience; In coherent homodyne apertureless scanning near-field optical microscopy (ASNOM) the background field cannot be fully suppressed because of the interference between the different collected fields, making the images difficult to interpret. We show that implementing the heterodyne version of ASNOM allows one to overcome this issue. We present a comparison between homodyne and heterodyne ASNOM through near-field analysis of gold nanowells, integrated waveguides, and a single evanescent wave generated by total internal reflection. The heterodyne approach allows for the control of the interferometric effect with the background light. In particular, the undesirable backgro…