An objective visual security assessment for cipher-images based on local entropy

2010 ◽  
Vol 53 (1) ◽  
pp. 75-95 ◽  
Author(s):  
Jing Sun ◽  
Zhengquan Xu ◽  
Jin Liu ◽  
Ye Yao
2021 ◽  
Vol 91 ◽  
pp. 107071
Author(s):  
Jian Xiong ◽  
Xinzhong Zhu ◽  
Jie Yuan ◽  
Ran Shi ◽  
Hao Gao

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Zhengguo Wu ◽  
Kai Zhang ◽  
Yannan Ren ◽  
Jing Li ◽  
Jiande Sun ◽  
...  

Selective encryption has been widely used in image privacy protection. Visual security assessment is necessary for the effectiveness and practicability of image encryption methods, and there have been a series of research studies on this aspect. However, these methods do not take into account perceptual factors. In this paper, we propose a new visual security assessment (VSA) by saliency-weighted structure and orientation similarity. Considering that the human visual perception is sensitive to the characteristics of selective encrypted images, we extract the structure and orientation feature maps, and then similarity measurements are conducted on these feature maps to generate the structure and orientation similarity maps. Next, we compute the saliency map of the original image. Then, a simple saliency-based pooling strategy is subsequently used to combine these measurements and generate the final visual security score. Extensive experiments are conducted on two public encryption databases, and the results demonstrate the superiority and robustness of our proposed VSA compared with the existing most advanced work.


2020 ◽  
pp. 29-34
Author(s):  
Alexandr V. Kostanovskiy ◽  
Margarita E. Kostanovskaya

Work is devoted to studying of a linear mode thermodynamic – a mode which is actively investigated now. One of the main concepts of a linear mode – local entropy rate of production. The purpose of given article consists in expansion of a circle of problems for which it is possible to calculate a local entropy rate of production, namely its definition, using the experimental “time-temperature” curves of heating/cooling. “Time-temperature” curves heating or cooling are widely used in non-stationary thermophysical experiments at studying properties of substances and materials: phase transitions of the first and second sort, a thermal capacity, thermal diffusivity. The quantitative substantiation of the formula for calculation of the local entropy rate of production in which it is used thermogram (change of temperature from time) which is received by a method of pulse electric heating is resulted. Initial time dependences of electric capacity and temperature are measured on the sample of niobium in a microsecond range simultaneously. Conformity of two dependences of the local entropy rate of production from time is shown: one is calculated under the known formula in which the brought electric capacity is used; another is calculated, using the thermogram.


Author(s):  
T.M. Yarkova ◽  

This article presents an analysis of the changes that have occurred in one of the most important state documents - the Food Security Doctrine of the Russian Federation. Criticism of this document can be traced in many scientific works: some experts attribute the Doctrine only to a program document, while others expect it to be implement and control, i.e. much more in practice. An assessment of the significance and essence of such a document as the doctrine as a whole made it possible to determine its place both in the system of public administration and the degree of its significance in the regulatory field. Based on the findings, an attempt was made to analyze changes in the new Doctrine of Food Security of the Russian Federation, approved by Decree of the President of Russia No. 20 of 01.21.2020. Structural changes in the new Doctrine are highlighted, as well as a critical assessment of the features of all its main sections. The greatest changes were revealed in the state food security assessment system, and it was also determined that the new version of the Doctrine has a greater social bias. If there are positive changes, some omissions of the most important areas of agri-food policy have been identified, which, despite their absence or insufficient reflection in the Doctrine, can be presented and decided at the level of subsequent documents, but only if the Doctrine in practice will be a fundamental document of public administration and regulatory framework.


Author(s):  
Bassam A. Hemade ◽  
Hamed A. Ibrahim ◽  
Hossam E.A. Talaat

Background: The security assessment plays a crucial role in the operation of the modern interconnected power system network. Methods: Hence, this paper addresses the application of k-means clustering algorithm equipped with Principal Component Analysis (PCA) and silhouette analysis for the classification of system security states. The proposed technique works on three principal axes; the first stage involves contingency quantification based on developed insecurity indices, the second stage includes dataset preparation to enhance the overall performance of the proposed method using PCA and silhouette analysis, and finally the application of the clustering algorithm over data. Results: The proposed composite insecurity index uses available synchronized measurements from Phasor Measurement Units (PMUs) to assess the development of cascading outages. Considering different operational scenarios and multiple levels of contingencies (up to N-3), Fast Decoupled Power Flow (FDPF) have been used for contingency replications. The developed technique applied to IEEE 14-bus and 57-bus standard test system for steady-state security evaluation. Conclusion: The obtained results ensure the robustness and effectiveness of the established procedure in the assessment of the system security irrespective of the network size or operating conditions.


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