scholarly journals Novel Implementation of Audio Encryption Using Pseudorandom Byte Generator

2021 ◽  
Vol 11 (21) ◽  
pp. 10190
Author(s):  
Borislav Stoyanov ◽  
Tsvetelina Ivanova
Keyword(s):  
Theoretical Analysis ◽  
Chaos Theory ◽  
Signal To Noise Ratio ◽  
Mathematical Function ◽  
Signal To Noise ◽  
Change Rate ◽  
Different Types ◽  
Audio Encryption ◽  
Noise Ratio ◽  
Audio Files

In this paper, we present an algorithm for encrypting audio files based on the Ikeda map, a mathematical function of chaos theory. Detailed experimental, security and theoretical analysis is provided on the proposed algorithm using histogram analysis, using different measurements including the signal-to-noise ratio, the peak signal-to-noise ratio, the number of samples change rate and the correlation coefficient. The provided results show a highly secure and strong algorithm against different types of attacks.

PERIODIC AND APERIODIC STOCHASTIC RESONANCE WITH OUTPUT SIGNAL-TO-NOISE RATIO EXCEEDING THAT AT THE INPUT

1999 ◽  
Vol 09 (01) ◽  
pp. 267-272 ◽  
Author(s):  
FRANÇOIS CHAPEAU-BLONDEAU
Keyword(s):  
Nonlinear System ◽  
Stochastic Resonance ◽  
Nonlinear Effect ◽  
Output Signal ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Practical Applications ◽  
Different Types ◽  
Signal Detectability ◽  
Noise Ratio

Stochastic resonance (SR) is a nonlinear effect whereby a system is able to improve, via noise addition, the detectability of a signal in noise. SR has been demonstrated with different types of systems and signals where in each case, an appropriate detectability measure is shown improvable at the output of the stochastic resonator when noise is added at its input. A complementary issue, important for practical applications of SR, is the possibility of making the signal detectability at the ouput exceed that at the input when noise is added. We demonstrate this possibility, for both periodic and aperiodic SR, with a simple nonlinear system that we show exactly tractable analytically.

scholarly journals STEGANOGRAFI MENGGUNAKAN METODE DISCRETE FOURIER TRANSFORM (DFT)

2018 ◽  
Vol 4 (2) ◽  
pp. 87
Author(s):  
Yuri Ariyanto ◽  
Rizky Ardiansyah ◽  
Bias Paris
Keyword(s):  
Fourier Transform ◽  
Discrete Fourier Transform ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Change Rate ◽  
Noise Ratio

Seiring dengan kemajuan teknologi, serangan terjadi pada industri photography di mana banyak penyalahgunaan foto yang memiliki hak cipta tanpa seijin pemilik foto tersebut. Karena itulah dibuat sebuah aplikasi yang berfungsi untuk menyisipkan watermark dengan menggunakan metode DFT (Discrete Fourier Transform). Metode tersebut adalah metode matematika yang sering digunakan dalam bidang elektronika dan komputer. Metode ini secara khusus digunakan untuk menyelesaikan masalah yang berhubungan dengan frekuensi, sehingga metode ini dapat digunakan dalam bidang citra digital. Metode ini diterapkan untuk melakukan penyisipan dan ekstraksi watermark pada citra penampung. Watermark tersebut disisipkan kedalam frekuensi domain pada gambar dan akan menghasilkan output citra ber-watermark atau embeded image. Hal ini adalah untuk mencegah penyalahgunaan hak cipta, namun watermark tersebut tidak nampak secara fisik. Hal ini dilakukan selain memberikan jaminan keamanan terhadap gambar, tapi juga tidak mengurangi estetika pada gambar tersebut. Analisa yang dilakukan adalah tingkat keberhasilan proses insertion dan extraction, serangan pada citra, uji kemiripan dengan pengujian NPCR (Number of Pixel of Change Rate), UACI (Unified Averaged Changed Intensity), dan PSNR (Peak Signal-to-Noise Ratio) pada proses insertion dan extraction. DFT disimpulkan aman terhadap serangan berupa cropping, resize, dan editing. Selain itu, dihasilkan nilai presentase perubahan yang rendah pada pengujian NPCR & UACI dan nilai yang tinggi pada pengujian PSNR.

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.

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.

Quantifying the Effects of Background Speech Babble on Preschool Children's Novel Word Learning in a Multisession Paradigm: A Preliminary Study

2020 ◽  
Vol 63 (1) ◽  
pp. 345-356
Author(s):  
Meital Avivi-Reich ◽  
Megan Y. Roberts ◽  
Tina M. Grieco-Calub
Keyword(s):  
Word Learning ◽  
Signal To Noise Ratio ◽  
Preschool Age ◽  
Exposure Condition ◽  
Signal To Noise ◽  
Verbal Recall ◽  
Referent Selection ◽  
Main Effect ◽  
Noise Ratio ◽  
Novel Word Learning

Purpose This study tested the effects of background speech babble on novel word learning in preschool children with a multisession paradigm. Method Eight 3-year-old children were exposed to a total of 8 novel word–object pairs across 2 story books presented digitally. Each story contained 4 novel consonant–vowel–consonant nonwords. Children were exposed to both stories, one in quiet and one in the presence of 4-talker babble presented at 0-dB signal-to-noise ratio. After each story, children's learning was tested with a referent selection task and a verbal recall (naming) task. Children were exposed to and tested on the novel word–object pairs on 5 separate days within a 2-week span. Results A significant main effect of session was found for both referent selection and verbal recall. There was also a significant main effect of exposure condition on referent selection performance, with more referents correctly selected for word–object pairs that were presented in quiet compared to pairs presented in speech babble. Finally, children's verbal recall of novel words was statistically better than baseline performance (i.e., 0%) on Sessions 3–5 for words exposed in quiet, but only on Session 5 for words exposed in speech babble. Conclusions These findings suggest that background speech babble at 0-dB signal-to-noise ratio disrupts novel word learning in preschool-age children. As a result, children may need more time and more exposures of a novel word before they can recognize or verbally recall it.

On the Signal-to-Noise Ratio for Boolean Functions

2020 ◽  
Vol E103.A (12) ◽  
pp. 1659-1665
Author(s):  
Yu ZHOU ◽  
Wei ZHAO ◽  
Zhixiong CHEN ◽  
Weiqiong WANG ◽  
Xiaoni DU
Keyword(s):  
Boolean Functions ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Noise Ratio
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