scholarly journals Blind Digital Images Tampering Detection Based on Singular Value Decomposition

2020 ◽  
Vol 13 (6) ◽  
pp. 338-348
Author(s):  
Nidhal Abbadi ◽  
◽  
Alyaa Mohsin ◽  
Keyword(s):  
Singular Value Decomposition ◽  
Digital Images ◽  
Singular Value ◽  
Suggested Method ◽  
Tampering Detection ◽  
Gray Image ◽  
Important Type ◽  
Wide Range ◽  
Object Rotation ◽  
Value Decomposition

The growing use of digital images in a wide range of applications, and growing the availability of many editing photo software, cause to emerge a challenge to discover the images tampering. In this paper, we proposed a method to detect the most important type of forgery image (copy and move). We suggested many steps to classify the image as forgery or non-forgery image, started with preprocessing (included, convert image to gray image, de-noising, and image resize). Then, the image will be divided into several overlapping blocks. For each block, feature extracted (used it as a matching feature) by using the singular value decomposition (SVD) transformation. According to these features, the pixels were collected in many main groups, and then these groups clustered to many subgroups. The weight for each main group can be determined by comparing the subgroups with each other according to suggested conditions. The number of subgroups and weights are used to classify images to forgery or non-forgery images. The accuracy of detection and classified the forgery images were up to 97%. The suggested method is robust for tampered object rotation, scaling, and change of illumination.

scholarly journals Periodicity of quasar and galaxy redshift

2020 ◽  
Vol 643 ◽  
pp. A160
Author(s):  
Arindam Mal ◽  
Sarbani Palit ◽  
Ujjwal Bhattacharya ◽  
Sisir Roy
Keyword(s):  
Singular Value Decomposition ◽  
Variable Mass ◽  
Singular Value ◽  
Periodicity Detection ◽  
Redshift Range ◽  
Periodicity Analysis ◽  
Wide Range ◽  
Galaxy Redshift ◽  
Value Decomposition ◽  
Periodic Components

Context. An approach for studying the large-scale structure of the Universe lies in the detection and analysis of periodicity of redshift values of extragalactic objects, galaxies, and quasi stellar objects (QSO), in particular. Moreover, the hypothesis of the existence of multiple periodicities in the redshift distributions deserves exploration. The task is compounded by the presence of confounding effects and measurement noise. Aims. Studies of periodicity detection in redshift values of extragalactic objects obtained from the Sloan Digital Sky Survey (SDSS) have been conducted in the past, largely based on the Fourier transform. The present study aims to revisit the same thing using the singular value decomposition (SVD) as the primary tool. Methods. Periodicity detection and the determination of the fundamental period have been performed using a standard spectral approach as well as a SVD-based approach for a variety of simulated datasets. The analysis of the quasar redshift data from DR12 and galaxy redshift dataset of DR10 from SDSS data has been carried out. Results. A wide range of periodicities are observed in different redshift ranges of the quasar datasets. For redshifts greater than 0.03, a period length of 0.2094 was determined while periodicities of 0.1210 and 0.0654 were obtained for redshift ranges (0.03, 1) and (3, 4), respectively. Twin periodicities of 0.1153 and 0.0807 were obtained for the redshift range (1, 3). Determining the ranges to be examined has been done based on histogram computation; the binwidths of which have been obtained by employing a kernel density estimation. The redshift sequence for the galaxy samples exhibits a somewhat different nature, but still contains periodic components. Twin periodicities of 0.0056 and 0.0079 were observed for a redshift range greater than 0.03. Conclusions. Galaxy and quasar redshift values form sequences, which are not only discrete in amplitude but also contain periodic components. The superiority of the singular value decomposition method over the spectral estimation approach, in redshift periodicity analysis especially from the point of view of robustness, is demonstrated through simulations. The existence of periodicity for quasar and galaxy families is thus firmly established, lending further support to the Hoyle-Narlikar variable mass theory.

Dynamic Response of the Manipulator Tip to a Random Excitation

1996 ◽  
Vol 118 (3) ◽  
pp. 629-632 ◽  
Author(s):  
Marek R. Kujath ◽  
Unyime O. Akpan
Keyword(s):  
Singular Value Decomposition ◽  
Dynamic Response ◽  
Random Excitation ◽  
Singular Value ◽  
Decomposition Technique ◽  
Damping Coefficients ◽  
Wide Range ◽  
Value Decomposition

The paper describes the tip responses of a flexible articulated manipulator to a stationary random excitation of the base. The expressions for the covariance tensors of the manipulator tip motion are developed in the base and the inertia frame. The singular value decomposition technique is applied for the derivation of expressions for the principal variances. The principal variances are computed and discussed for a wide range of manipulator configurations and damping coefficients.

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