Letters: Television signal-to-noise ratio before and after demodulation

1979 ◽  
Vol 49 (3) ◽  
pp. 150 ◽  
Author(s):  
J.L. Eaton ◽  
B.W. Osborne
Keyword(s):  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Television Signal ◽  
Before And After ◽  
Noise Ratio

Letters: Television signal-to-noise ratio before and after demodulation

1978 ◽  
Vol 48 (9) ◽  
pp. 444
Author(s):  
D. Maurice ◽  
J.W. Allnatt ◽  
George H. Hagn ◽  
B.W. Osborne
Keyword(s):  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Television Signal ◽  
Before And After ◽  
Noise Ratio

Television signal-to-noise ratio before and after demodulation

1977 ◽  
Vol 47 (12) ◽  
pp. 555
Author(s):  
B.W. Osborne
Keyword(s):  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Television Signal ◽  
Before And After ◽  
Noise Ratio

Speech in noise testing before and after grommet insertion

2012 ◽  
Vol 126 (10) ◽  
pp. 1010-1015 ◽  
Author(s):  
V Possamai ◽  
G Kirk ◽  
A Scott ◽  
D Skinner
Keyword(s):  
Small Group ◽  
Background Noise ◽  
Signal To Noise Ratio ◽  
Sound Field ◽  
Noise Signal ◽  
Signal To Noise ◽  
Speech In Noise ◽  
Before And After ◽  
Noise Test ◽  
Noise Ratio

AbstractObjectives:To assess the feasibility of designing and implementing a speech in noise test in children before and after grommet insertion, and to analyse the results of such a test in a small group of children.Methods:Twelve children aged six to nine years who were scheduled to undergo grommet insertion were identified. They underwent speech in noise testing before and after grommet insertion. This testing used Arthur Boothroyd word lists read at 60 dB in four listening conditions presented in a sound field: firstly in quiet conditions, then in signal to noise ratios of +10 (50 dB background noise), 0 (60 dB) and −10 (70 dB).Results:Mean phoneme scores were: in quiet conditions, 28.1 pre- and 30 post-operatively (p = 0.04); in 50 dB background noise (signal to noise ratio +10), 24.2 pre- and 29 post-operatively (p < 0.01); in 60 dB background noise (signal to noise ratio 0), 22.6 pre- and 27.5 post-operatively (p = 0.06); and in 70 dB background noise (signal to noise ratio −10), 13.9 pre- and 21 post-operatively (p = 0.05).Conclusion:This small study suggests that speech in noise testing is feasible in this scenario. Our small group of children demonstrated a significant improvement in speech in noise scores following grommet insertion. This is likely to translate into a significant advantage in the educational environment.

Study of the Stability of 4H-SiC Detectors by Thermal Neutron Irradiation

2015 ◽  
Vol 821-823 ◽  
pp. 875-878 ◽  
Author(s):  
Fatima Issa ◽  
Laurent Ottaviani ◽  
Vanessa Vervisch ◽  
Dora Szalkai ◽  
Ludo Vermeeren ◽  
...  
Keyword(s):  
Thermal Neutron ◽  
Leakage Current ◽  
Signal To Noise Ratio ◽  
Pulse Height ◽  
Semiconductor Detectors ◽  
Signal To Noise ◽  
Metallic Contact ◽  
Thermal Neutron Irradiation ◽  
Before And After ◽  
Noise Ratio

Two types of 4H-SiC semiconductor detectors (D1 and D2) are realized based on ion implantation of 10B inside the aluminum metallic contact. The first detector shows a high leakage current after 10B implantation and low signal to noise ratio. However, improvements concerning the implantation parameters led to lower leakage current and thus to higher signal to noise ratio. Moreover such detectors show their stability under different thermal neutron fluxes showing the reproducible features of the pulse height spectra and same electrical behaviour before and after irradiation.

FM Television Signal-to-Noise Ratio

1976 ◽  
Vol CATV-1 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Lorimer Clayton
Keyword(s):  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Television Signal ◽  
Noise Ratio

Artifact Robustness, Inter- and Intraindividual Baseline Stability, and Rational EEG Parameter Selection

2002 ◽  
Vol 96 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Jörgen Bruhn ◽  
Thomas W. Bouillon ◽  
Andreas Hoeft ◽  
Steven L. Shafer
Keyword(s):  
Shannon Entropy ◽  
Signal To Noise Ratio ◽  
Approximate Entropy ◽  
Signal To Noise ◽  
Spectral Edge Frequency ◽  
Spectral Edge ◽  
Median Baseline ◽  
Before And After ◽  
Artifact Rejection ◽  
Noise Ratio

Background Artifact robustness (i.e., size of deviation of an electroencephalographic parameter value from baseline caused by artifacts) and baseline stability (i.e., consistency of median baseline values) of electroencephalographic parameters profoundly influence electroencephalography-based pharmacodynamic parameter estimation and the usefulness of the processed electroencephalogram as measure of the arousal state of the central nervous system (depth of anesthesia). In this study, the authors compared the artifact robustness and the interindividual and intraindividual baseline stability of several univariate descriptors of the electroencephalogram (Shannon entropy, approximate entropy, spectral edge frequency 95, delta ratio, and canonical univariate parameter). Methods Electroencephalographic data of 16 healthy volunteers before and after administration of an intravenous bolus of propofol (2 mg/kg body weight) were analyzed. Each volunteer was studied twice. The baseline electroencephalogram was recorded for a median of 18 min before drug administration. For each electroencephalographic descriptor, the authors calculated the following: (1) baseline variability (= (median baseline - median effect) [i.e., signal]/SD baseline [i.e., noise]) without artifact rejection; (2) baseline variability with artifact rejection; and (3) baseline stability within and between individuals (= (median baseline - median effect) averaged over all volunteers/SD of all median baselines). Results Without artifact rejection, Shannon entropy and canonical univariate parameter displayed the highest signal-to-noise ratio. After artifact rejection, approximate entropy, Shannon entropy, and the canonical univariate parameter displayed the highest signal-to-noise ratio. Baseline stability within and between individuals was highest for approximate entropy. Conclusions With regard to robustness against artifacts, the electroencephalographic entropy parameters and the canonical univariate parameter were superior to spectral edge frequency 95 and delta ratio. Electroencephalographic approximate entropy displayed the best interindividual and intraindividual baseline stability.

scholarly journals Implementation of Playfair Cipher and Least Significant Bit Algorithms in Digital Imagery

2020 ◽  
Vol 4 (3) ◽  
pp. 454-461
Author(s):  
Hermansa ◽  
Rusydi Umar ◽  
Anton Yudhana
Keyword(s):  
Signal To Noise Ratio ◽  
Digital Imagery ◽  
Least Significant Bit ◽  
Signal To Noise ◽  
Encryption And Decryption ◽  
Before And After ◽  
Noise Ratio ◽  
The Right ◽  
Right To Read

Message security is very important now. Because security is part of the privacy of someone who wants to protect messages from those who do not have the right to read or receive them. The method used for securing information messages with message encryption and decryption techniques is the Playfair Cipher algorithm combined with the Least Significant Bit (LSB) method. In this study it was found that the Playfair Cipher algorithm is quite safe in implementing cryptographic encryption or ciphertext because the playfair cipher has a level of appearance of letters that is so difficult to predict so that the ciphertext becomes a randomized collection of data. For the Least Significant Bit (LSB) steganography method in the insertion of a secret or embedded message it is difficult to guess in plain view the changes that occur between before and after the image is inserted are not too significant. Also see the value of the Peak-Signal-to-Noise ratio or PSNR can still be considered good quality due to> 30 decibels (dB). So the final result of the combination of the Playfair Cipher algorithm with the Least Significant Bit (LSB) method is quite good in securing messages.

scholarly journals Wavelet Transform Image Enhancement Algorithm-Based Evaluation of Lung Recruitment Effect and Nursing of Acute Respiratory Distress Syndrome by Ultrasound Image

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Wangyan Jin ◽  
Ling Dai ◽  
Liuyan Ge ◽  
Xuhua Huang ◽  
Guanhua Xu ◽  
...  
Keyword(s):  
Acute Respiratory Distress Syndrome ◽  
Distress Syndrome ◽  
Signal To Noise Ratio ◽  
Ultrasound Image ◽  
Ultrasound Images ◽  
Signal To Noise ◽  
Running Time ◽  
Before And After ◽  
Noise Ratio ◽  
Enhancement Algorithm

This study aimed to analyze the application of ultrasound images of lung recruitment (LR) nursing treatment guided by positive-end expiratory pressure (PEEP) in patients with acute respiratory distress syndrome (ARDS). An ultrasound image enhancement algorithm (UIEA) wavelet transform (WT) was constructed, and the soft threshold (ST) and adjacent region average (ARA) were introduced for simulation comparison. In addition, the signal-to-noise ratio (SNR), peak signal-to-noise ratio (PSNR), and running time were undertaken as the evaluation indexes. The WT algorithm was applied to the ultrasound images of 85 ARDS patients before and after PEEP recruitment. The mean artery pressure (MAP), heart rate (HR), and central venous pressure (CVP), peak inspiratory pressure (Ppeak), mean inspiratory pressure (Pmean), dynamic lung compliance (DLC), PCO2, and PaO2/FiO2 of the patients were recorded before and after the LR. The results showed that the signal-to-noise ratio (SNR) (19.67 ± 3.15 dB) and PSNR (23.08 ± 2.08 dB) of the images enhanced by the WT algorithm were much higher than those of ST (13.88 ± 2.74 dB and 14.62 ± 1.76 dB, respectively) and ARA (14.96 ± 3.06 dB and 15.11 ± 1.94 dB, respectively), while the running time was in adverse ( P < 0.05 ); the HR and CVP of patients after LR nursing treatment were increased greatly, while the MAP was in the opposite case ( P < 0.05 ); after LR nursing treatment, Ppeak, Pmean, DLC, PCO2, and PaO2/FiO2 of the patient were significantly greater than those before the LR, and the difference was statistically significant ( P < 0.05 ). In short, the WT algorithm not only enhanced the quality of ultrasound images but also shortened the running time and improved the processing efficiency. PEEP LR nursing treatment could effectively improve the vascular patency, cardiac ejection capacity, and DLC in patients with ARDS, thereby increasing the airway pressure and maintaining the unobstructed expiration.

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.

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