scholarly journals Proof-of-Principle of a Cherenkov-Tag Detector Prototype

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3437
Author(s):  
Giuseppe Gallo ◽  
Domenico Lo Presti ◽  
Danilo Luigi Bonanno ◽  
Giovanni Bonanno ◽  
Paola La Rocca ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Preliminary Test ◽  
Correct Identification ◽  
Electronic Noise ◽  
Signal To Noise ◽  
Transparent Material ◽  
Muon Tracking ◽  
The University ◽  
Reduced Scale ◽  
Proof Of Principle

In a recent paper, the authors discussed the feasibility study of an innovative technique based on the directionality of Cherenkov light produced in a transparent material to improve the signal to noise ratio in muon imaging applications. In particular, the method was proposed to help in the correct identification of incoming muons direction. After the first study by means of Monte Carlo simulations with Geant4, the first reduced scale prototype of such a detector was built and tested at the Department of Physics and Astronomy "E. Majorana" of the University of Catania (Italy). The characterization technique is based on muon tracking by means of the prototype in coincidence with two scintillating tiles. The results of this preliminary test confirm the validity of the technique and stressed the importance to enhance the Cherenkov photons production to get a signal well distinguishable with respect to sensors and electronic noise.

Quantitative Assessment of Penetration Depth in Clinical Ultrasound Systems

2007 ◽  
Author(s):  
Franco Marinozzi ◽  
Fabiano Bini ◽  
Federico Patane` ◽  
Daniele Piras
Keyword(s):  
Penetration Depth ◽  
Correlation Coefficient ◽  
Quantitative Assessment ◽  
Signal To Noise Ratio ◽  
Electronic Noise ◽  
Grey Level ◽  
Signal To Noise ◽  
Time And Space ◽  
Depth Of Penetration ◽  
Speckle Contrast

Most of the recent studies for image uniformity assessment involve signal to noise ratio (SNR) analysis computed over various combinations of mean grey level and variance [1–2] to quantify the speckle contrast and hence the depth of penetration (DOP). Speckle is auto correlated in time but not in space. Electronic noise always present at the bottom of the image, instead, is uncorrelated both in time and space. The extension of the area in which only the speckle is visible, gives an estimate of the penetration depth. The correlation coefficient of two subsequently acquired frames can be computed to quantify image uniformity where depth at which the correlation coefficient falls below a fixed threshold is defined as penetration depth.

A discussion on infared astronomy - High resolution spectra of the Sun

1969 ◽  
Vol 264 (1150) ◽  
pp. 171-182 ◽  
Keyword(s):  
Near Infrared ◽  
Signal To Noise Ratio ◽  
Solar Spectrum ◽  
Instrumental Function ◽  
Signal To Noise ◽  
Maximum Resolution ◽  
Scientific Station ◽  
Under Construction ◽  
The University ◽  
Absorption Features

The University of Liege has operated, since 1958, a laboratory of solar spectroscopy at the International Scientific Station of the Jungfraujoch (Switzerland). During recent years, much effort has been devoted in two main directions: ( a ) techniques of correction for the effects of the instrumental function to obtain the best possible knowledge of central intensities and profiles of photospheric lines; ( b )increase of the signal to noise ratio in the records in order to detect and measure very faint absorption features. In addition, a balloon-borne equipment is now under construction in Liege to observe, with maximum resolution, the near infrared solar spectrum from an altitude of about 80 000 ft.

ENHANCEMENT OF DETECTABILITY OF NOISY SIGNALS BY STOCHASTIC RESONANCE IN ARRAYS

2004 ◽  
Vol 14 (05) ◽  
pp. 1655-1670 ◽  
Author(s):  
ZONGHUA LIU ◽  
YING-CHENG LAI ◽  
ARJE NACHMAN
Keyword(s):  
Stochastic Resonance ◽  
Laboratory Experiments ◽  
Signal To Noise Ratio ◽  
Nonlinear Oscillators ◽  
Collective Effect ◽  
Signal To Noise ◽  
Noise Sources ◽  
Noisy Signals ◽  
Periodic Signals ◽  
Proof Of Principle

We propose a scheme to detect signals immersed in strong, externally imposed, undesirable noise (jamming) by making use of the principle of stochastic resonance. The strategy is to construct an array of simple nonlinear oscillators and to apply independent, modulating noise to each oscillator. We show that the collective effect of all oscillators and the interplay between nonlinearity and different noise sources can enhance the detectability of the original signal. For proof of principle we focus on periodic signals mixed with in-band, Gaussian jamming. In particular, we show by both extensive numerical computations and physical arguments that measures of the detectability such as the signal-to-noise ratio can be increased in our scheme. We suggest how the scheme can be implemented in laboratory experiments.

Determination of the Best Emulsion for the Microscopy of Crystals

1981 ◽  
Vol 39 ◽  
pp. 32-33
Author(s):  
David A. Grano ◽  
Kenneth H. Downing
Keyword(s):  
Spatial Frequency ◽  
Information Transfer ◽  
Signal To Noise Ratio ◽  
Experimental Situation ◽  
Photographic Emulsion ◽  
Modulation Transfer ◽  
Signal To Noise ◽  
Frequency Space ◽  
Noise Ratio

The retrieval of high-resolution information from images of biological crystals depends, in part, on the use of the correct photographic emulsion. We have been investigating the information transfer properties of twelve emulsions with a view toward 1) characterizing the emulsions by a few, measurable quantities, and 2) identifying the “best” emulsion of those we have studied for use in any given experimental situation. Because our interests lie in the examination of crystalline specimens, we've chosen to evaluate an emulsion's signal-to-noise ratio (SNR) as a function of spatial frequency and use this as our critereon for determining the best emulsion.The signal-to-noise ratio in frequency space depends on several factors. First, the signal depends on the speed of the emulsion and its modulation transfer function (MTF). By procedures outlined in, MTF's have been found for all the emulsions tested and can be fit by an analytic expression 1/(1+(S/S0)2). Figure 1 shows the experimental data and fitted curve for an emulsion with a better than average MTF. A single parameter, the spatial frequency at which the transfer falls to 50% (S0), characterizes this curve.

Experiments in Bright-Field Imaging with Hollow-Cone Illumination

1981 ◽  
Vol 39 ◽  
pp. 226-227
Author(s):  
W. Kunath ◽  
K. Weiss ◽  
E. Zeitler
Keyword(s):  
Signal To Noise Ratio ◽  
Carbon Support ◽  
Electronic System ◽  
Optic Axis ◽  
Hollow Cone ◽  
Signal To Noise ◽  
Bright Field ◽  
Noise Ratio ◽  
Single Field ◽  
Field Imaging

Bright-field images taken with axial illumination show spurious high contrast patterns which obscure details smaller than 15 ° Hollow-cone illumination (HCI), however, reduces this disturbing granulation by statistical superposition and thus improves the signal-to-noise ratio. In this presentation we report on experiments aimed at selecting the proper amount of tilt and defocus for improvement of the signal-to-noise ratio by means of direct observation of the electron images on a TV monitor.Hollow-cone illumination is implemented in our microscope (single field condenser objective, Cs = .5 mm) by an electronic system which rotates the tilted beam about the optic axis. At low rates of revolution (one turn per second or so) a circular motion of the usual granulation in the image of a carbon support film can be observed on the TV monitor. The size of the granular structures and the radius of their orbits depend on both the conical tilt and defocus.

Correlation averaging of two-dimensional crystals: basic strategy and refinements

1986 ◽  
Vol 44 ◽  
pp. 136-139
Author(s):  
W. Baumeister ◽  
R. Rachel ◽  
R. Guckenberger ◽  
R. Hegerl
Keyword(s):  
Low Dose ◽  
Signal To Noise Ratio ◽  
Real Space ◽  
Fourier Domain ◽  
Two Dimensional ◽  
Signal To Noise ◽  
Unit Cells ◽  
Lateral Displacements ◽  
Established Technique ◽  
Crystalline Array

IntroductionCorrelation averaging (CAV) is meanwhile an established technique in image processing of two-dimensional crystals /1,2/. The basic idea is to detect the real positions of unit cells in a crystalline array by means of correlation functions and to average them by real space superposition of the aligned motifs. The signal-to-noise ratio improves in proportion to the number of motifs included in the average. Unlike filtering in the Fourier domain, CAV corrects for lateral displacements of the unit cells; thus it avoids the loss of resolution entailed by these distortions in the conventional approach. Here we report on some variants of the method, aimed at retrieving a maximum of information from images with very low signal-to-noise ratios (low dose microscopy of unstained or lightly stained specimens) while keeping the procedure economical.

Information capacity and bandwidth limitations in the SEM

1989 ◽  
Vol 47 ◽  
pp. 84-85
Author(s):  
D. C. Joy ◽  
R. D. Bunn
Keyword(s):  
Signal To Noise Ratio ◽  
Critical Dimension ◽  
Information Capacity ◽  
Acquisition Time ◽  
Signal To Noise ◽  
Sem Image ◽  
Probe Size ◽  
Minimum Number ◽  
Noise Ratio ◽  
Signal Channel

The information available from an SEM image is limited both by the inherent signal to noise ratio that characterizes the image and as a result of the transformations that it may undergo as it is passed through the amplifying circuits of the instrument. In applications such as Critical Dimension Metrology it is necessary to be able to quantify these limitations in order to be able to assess the likely precision of any measurement made with the microscope.The information capacity of an SEM signal, defined as the minimum number of bits needed to encode the output signal, depends on the signal to noise ratio of the image - which in turn depends on the probe size and source brightness and acquisition time per pixel - and on the efficiency of the specimen in producing the signal that is being observed. A detailed analysis of the secondary electron case shows that the information capacity C (bits/pixel) of the SEM signal channel could be written as :

Speech Reception in the Presence of Classroom Noise

1979 ◽  
Vol 10 (4) ◽  
pp. 221-230 ◽  
Author(s):  
Veronica Smyth
Keyword(s):  
Signal To Noise Ratio ◽  
Learning Processes ◽  
Speech Discrimination ◽  
Signal To Noise ◽  
Speech Reception ◽  
Monosyllabic Words ◽  
Noise Ratio

Three hundred children from five to 12 years of age were required to discriminate simple, familiar, monosyllabic words under two conditions: 1) quiet, and 2) in the presence of background classroom noise. Of the sample, 45.3% made errors in speech discrimination in the presence of background classroom noise. The effect was most marked in children younger than seven years six months. The results are discussed considering the signal-to-noise ratio and the possible effects of unwanted classroom noise on learning processes.

Effects of Fundamental Frequency Contours on Sentence Recognition in Mandarin-Speaking Children With Cochlear Implants

2020 ◽  
Vol 63 (11) ◽  
pp. 3855-3864
Author(s):  
Wanting Huang ◽  
Lena L. N. Wong ◽  
Fei Chen ◽  
Haihong Liu ◽  
Wei Liang
Keyword(s):  
Cochlear Implants ◽  
Fundamental Frequency ◽  
Signal To Noise Ratio ◽  
Lexical Tone ◽  
Signal To Noise ◽  
Sentence Recognition ◽  
Test Conditions ◽  
Age Appropriate ◽  
F0 Contour ◽  
Appropriate Sentences

Purpose Fundamental frequency (F0) is the primary acoustic cue for lexical tone perception in tonal languages but is processed in a limited way in cochlear implant (CI) systems. The aim of this study was to evaluate the importance of F0 contours in sentence recognition in Mandarin-speaking children with CIs and find out whether it is similar to/different from that in age-matched normal-hearing (NH) peers. Method Age-appropriate sentences, with F0 contours manipulated to be either natural or flattened, were randomly presented to preschool children with CIs and their age-matched peers with NH under three test conditions: in quiet, in white noise, and with competing sentences at 0 dB signal-to-noise ratio. Results The neutralization of F0 contours resulted in a significant reduction in sentence recognition. While this was seen only in noise conditions among NH children, it was observed throughout all test conditions among children with CIs. Moreover, the F0 contour-induced accuracy reduction ratios (i.e., the reduction in sentence recognition resulting from the neutralization of F0 contours compared to the normal F0 condition) were significantly greater in children with CIs than in NH children in all test conditions. Conclusions F0 contours play a major role in sentence recognition in both quiet and noise among pediatric implantees, and the contribution of the F0 contour is even more salient than that in age-matched NH children. These results also suggest that there may be differences between children with CIs and NH children in how F0 contours are processed.

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