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Wyszukujesz frazę "random decomposition" wg kryterium: Temat


Wyświetlanie 1-8 z 8
Tytuł:
Audio and image encryption scheme based on QR decomposition and random modulus decomposition in Fresnel domain
Autorzy:
Anjana, Savita
Yadav, Ak
Singh, Phool
Singh, Hukum
Powiązania:
https://bibliotekanauki.pl/articles/2172830.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
QR decomposition
audio encryption
random modulus decomposition
Opis:
In this paper, an asymmetric audio and image encryption mechanism using QR decomposition and random modulus decomposition (RD) in the Fresnel domain is proposed. The audio file is recorded as a vector and converted to a two-dimensional array to act as an image or a sound map. This sound map is encrypted using the image encryption algorithm proposed in this paper. The proposed cryptosystem is validated for both audios and grayscale images. Fresnel parameters and the two private keys obtained from QR decomposition and random modulus decomposition (RD) form the key space. Computer-based reproductions have been carried out to prove the validity and authenticity of the scheme. Simulation results authenticate that the scheme is robust and efficient against various attacks and is sensitive to input parameters.
Źródło:
Optica Applicata; 2022, 52, 3; 359--374
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Image encryption algorithm based on rear-mounted phase mask and random decomposition
Autorzy:
Yadav, Shivani
Singh, Hukum
Powiązania:
https://bibliotekanauki.pl/articles/2086758.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fractional Fourier transform
random decomposition
rear-mounted phase mask
SVD
singular value decomposition
Opis:
To escalate the image encryption a new method has been devised which includes double random phase encoding (DRPE) using rear phase masking and random decomposition (RD) technique stranded on fractional Fourier transform. Here, asymmetric cryptographic system is developed in fractional Fourier transform (FrFT) mode using two random phase masks (RPM) and a rear mounted phase mask. In the projected scheme a colored image is decomposed into R, G and B channels. The amplitude of each channel is normalized, phase encoded and modulated using RPM. The modulated R, G and B channels of the colored image are individually transformed using FrFT to produce corresponding encrypted image. The proposed scheme is authorized on grayscale image also. The norm behind the development of the suggested scheme has been elaborated by carrying out cryptanalysis on system based on the RD. The method helps in escalations of the protection of double random phase encoding by cumulating the key length and the parameter amount, so that it vigorously can be used against various attacks. The forte of the suggested cryptographic system was verified using simulations with MATLAB 7.9.0 (R2008a). The efficiency of the suggested scheme includes the analysis using singular value decomposition (SVD), histogram and correlation coefficient.
Źródło:
Optica Applicata; 2022, 52, 2; 195--212
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Method of optimal linear extrapolation of vector random sequences with full consideration of correlation connections for each component
Metod optimal'noy linejjnojj ehstrapoljacija vektornykh sluchajjnykh posledovatel'nostejj s polnym uchetom korreljacionnykh svjazejj dlja kazhdogo komponenta
Autorzy:
Atamanjuk, I.
Kondratenko, Y.
Powiązania:
https://bibliotekanauki.pl/articles/76650.pdf
Data publikacji:
2015
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
extrapolation
vector random sequence
algorithm
block diagram
canonical decomposition
Źródło:
Motrol. Motoryzacja i Energetyka Rolnictwa; 2015, 17, 2
1730-8658
Pojawia się w:
Motrol. Motoryzacja i Energetyka Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Linear Cholesky decomposition of covariance matrices in mixed models with correlated random effects
Autorzy:
Rabe, Anasu
Shangodoyin, D. K.
Thaga, K.
Powiązania:
https://bibliotekanauki.pl/articles/1186928.pdf
Data publikacji:
2019-12-10
Wydawca:
Główny Urząd Statystyczny
Tematy:
correlated random effects
covariance matrix
linear Cholesky decomposition
linear mixed models
Opis:
Modelling the covariance matrix in linear mixed models provides an additional advantage in making inference about subject-specific effects, particularly in the analysis of repeated measurement data, where time-ordering of the responses induces significant correlation. Some difficulties encountered in these modelling procedures include high dimensionality and statistical interpretability of parameters, positive definiteness constraint and violation of model assumptions. One key assumption in linear mixed models is that random errors and random effects are independent, and its violation leads to biased and inefficient parameter estimates. To minimize these drawbacks, we developed a procedure that accounts for correlations induced by violation of this key assumption. In recent literature, variants of Cholesky decomposition were employed to circumvent the positive definiteness constraint, with parsimony achieved by joint modelling of mean and covariance parameters using covariates. In this article, we developed a linear Cholesky decomposition of the random effects covariance matrix, providing a framework for inference that accounts for correlations induced by covariate(s) shared by both fixed and random effects design matrices, a circumstance leading to lack of independence between random errors and random effects. The proposed decomposition is particularly useful in parameter estimation using the maximum likelihood and restricted/residual maximum likelihood procedures.
Źródło:
Statistics in Transition new series; 2019, 20, 4; 59-70
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ensemble-based Method of Fraud Detection at Self-checkouts in Retail
Autorzy:
Vitynskyi, P.
Tkachenko, R.
Izonin, I.
Powiązania:
https://bibliotekanauki.pl/articles/410756.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
classification
Ensemble-based method
Random Forest
fraud detection
retail
Ito decomposition
imbalanced dataset
Opis:
The authors consider the problem of fraud detection at self-checkouts in retail in condition of unbalanced data set. A new ensemble-based method is proposed for its effective solution. The developed method involves two main steps: application of the preprocessing procedures and the Random Forest algorithm. The step-by-step implementation of the preprocessing stage involves the sequential execution of such procedures over the input data: scaling by maximal element in a column with row-wise scaling by Euclidean norm, weighting by correlation and applying polynomial extension. For polynomial extension Ito decomposition of the second degree is used. The simulation of the method was carried out on real data. Evaluating performance was based on the use of cost matrix. The experimental comparison of the effectiveness of the developed ensemble-based method with a number of existing (simples and ensembles) demonstrates the best performance of the developed method. Experimental studies of changing the parameters of the Random Forest both for the basic algorithm and for the developed method demonstrate a significant improvement of the investigated efficiency measures of the latter. It is the result of all steps of the preprocessing stage of the developed method use.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2019, 8, 2; 3-8
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Jitter generation model based on timing modulation and cross point calibration for jitter decomposition
Autorzy:
Ren, Nan
Fu, Zaiming
Lei, Shengcu
Liu, Hanglin
Tian, Shulin
Powiązania:
https://bibliotekanauki.pl/articles/1848967.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
jitter decomposition
jitter generation
cross-point calibration
timing modulation
deterministic jitter
random jitter
Opis:
High-speed serial standards are rapidly developing, and with a requirement for effective compliance and characterization measurement methods. Jitter decomposition consists in troubleshooting steps based on jitter components from decomposition results. In order to verify algorithms with different deterministic jitter (DJ) in actual circuits, jitter generation model by cross-point calibration and timing modulation for jitter decomposition is presented in this paper. The generated jitter is pre-processed by cross-point calibration which improves the accuracy of jitter generation. Precisely controllable DJ and random jitter (RJ) are generated by timing modulation such as data-dependent jitter (DDJ), duty cycle distortion (DCD), bounded uncorrelated jitter (BUJ), and period jitter (PJ). The benefit of the cross-point calibration was verified by comparing generation of controllable jitter with and without cross-point calibration. The accuracy and advantage of the proposed method were demonstrated by comparing with the method of jitter generation by analog modulation. Then, the validity of the proposed method was demonstrated by hardware experiments where the jitter frequency had an accuracy of ±20 ppm, the jitter amplitude ranged from 10 ps to 8.33 ns, a step of 2 ps or 10 ps, and jitter amplitude was independent of jitter frequency and data rate.
Źródło:
Metrology and Measurement Systems; 2021, 28, 1; 123-143
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New formula for the failure/repair frequency of multi-state monotone systems and its applications
Autorzy:
Korczak, E.
Powiązania:
https://bibliotekanauki.pl/articles/969720.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
multi-state monotone systems
availability
repair frequency
binary representation
Shannon decomposition
random demand
Opis:
The paper deals with calculation methods for failure and repair frequencies of multi-state monotone systems, both for the instantaneous and steady state cases. First, the fixed demand is considered. Based on the binary representation of multi-state structure, we have obtained a new formula for the failure/repair frequency. This formula is used to derive simple rules for the calculation of failure/repair frequency. These rules show how to convert an expression for the system availability into appropriate expression for the system failure/repair frequency. The applicability of the rules is illustrated by some examples. Finally, expressions for the failure/repair frequency for systems operating under random demand are obtained. Since both input and output data have similar format, the rules can be used in a recursive manner, allowing easy analysis of complex systems with hierarchical structure.
Źródło:
Control and Cybernetics; 2007, 36, 1; 219-239
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wykorzystanie modelowania wielopoziomowego w analizie jakości życia
An application of multilevel modelling in subjective well-being studies
Autorzy:
Suchecka, Jadwiga
Łaszkiewicz, Edyta
Powiązania:
https://bibliotekanauki.pl/articles/587316.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
Dekompozycja wariancji
Efekty losowe
Europejski Sondaż Społeczny
Modele hierarchiczne
European Social Survey
Hierarchical models
Random effects
Variance decomposition
Opis:
Modele wielopoziomowe umożliwiają jednoczesną analizę procesu na kilku poziomach agregacji danych. W związku z tym formułowane na ich podstawie wnioski mogą rozszerzać rozumienie natury relacji między czynnikami o charakterze mikro i mezo (lub makro) a zmienną wynikową. Celem badania jest zademonstrowanie możliwości wykorzystania modelowania wielopoziomowego w badaniach jakości życia. W badaniu skorzystano z ogólnodostępnych danych mikro, pochodzących z trzech fal badania (2010, 2012, 2014) Europejskiego Sondażu Społecznego. Uzyskane wyniki potwierdzają wnioski z dotychczasowych badań, wskazując, iż poziom subiektywnie deklarowanej satysfakcji życiowej determinowany jest profilem społeczno-ekonomicznym i demograficznym jednostki. Wykorzystanie modelowania wielopoziomowego pozwoliło stwierdzić, iż poziom zaufania do ludzi i władz, rozpatrywany na poziomie regionalnym, oddziałuje silniej na zmiany poziomu zadowolenia z życia niż zaufanie deklarowane na poziomie mikro.
Multilevel models allow for the simultaneous analysis of process on the several levels of data aggregation. Therefore, the conclusions formulated on them can broaden the understanding of the nature of the relationship between micro and mezo (or macro) factors and the outcome variable. The aim of the study is to demonstrate the potential for multi-level modelling in the quality of life studies. In this study, we used publicly available micro data from three waves of the European Social Survey (2010, 2012, 2014). Our results confirm the conclusions of previous researches, indicating that the level of subjectively declared life satisfaction is determined by the socio-economic and demographic profile of the individual. An application of the multilevel models enables us to conclude that the level of trust in people and authorities at the regional level affects life satisfaction stronger than the trust expressed at the micro level.
Źródło:
Studia Ekonomiczne; 2017, 344; 133-144
2083-8611
Pojawia się w:
Studia Ekonomiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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