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Li Y.,Beijing University of Posts and Telecommunications | Liu N.,Beijing Electronic Science and Technology Institute | Zhang B.,China Information Security Certification Center | Yuan K.-G.,Beijing University of Posts and Telecommunications | Yang Y.-X.,Beijing University of Posts and Telecommunications
Dianzi Yu Xinxi Xuebao/Journal of Electronics and Information Technology | Year: 2015

For the consideration of the multiple copy-move forgery detection of digital images, and to avoid missing the matching feature points when generalized 2 Nearest-Neighbor (g2NN) algorithm is applied, Reversed generalized 2 Nearest-Neighbor (Rg2NN) algorithm is proposed. Reverse order is used in feature points matching, so that all feature points that match with the detected point can be calculated accurately. The experiment results show that the matching feature points calculated by Rg2NN are more accurate than by g2NN, and the ability of g2NN in detecting multiple copy-move forgery is improved. When one patch in the image is copied and pasted multiple times or two or more patches are copied and pasted, the copy-move map can be localized precisely by the Rg2NN algorithm. ©, 2015, Science Press. All right reserved.

Tian D.,Beihang University | Guo Z.,Beihang University | Wang Y.,China Information Security Certification Center | Li W.,University of Wollongong | And 4 more authors.
Advanced Functional Materials | Year: 2014

Controllable surface adhesion of solid substrates has aroused great interest both in air and underwater in solving many challenging interfacial science problems such as robust antifouling, oil-repellent, and highly efficient oil/water separation materials. Recently, responsive surface adhesion, especially switchable adhesion, under external stimulus in air has been paid more and more attention in fundamental research and industrial applications. However, phototunable underwater oil adhesion is still a challenge. Here, an approach to realize phototunable underwater oil adhesion on aligned ZnO nanorod array-coated films is reported, via a special switchable contact mode between an unstable liquid/gas/solid tri-phase contact mode and stable liquid/liquid/solid tri-phase contact mode. The photo-induced wettability transition to water and air exists (or does not) in the micro/nanoscale hierarchical structure of the mesh films, playing important role in controlling the underwater oil adhesion behavior. This work is promising in the design of novel interfacial materials and functional devices for practical applications such as photo-induced underwater oil manipulation and release, with loss-free oil droplet transportation. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gao J.-B.,Nanchang Hangkong University | Gao J.-B.,Shanghai JiaoTong University | Zhang B.-W.,Shanghai JiaoTong University | Chen X.-H.,China Information Security Certification Center
MATEC Web of Conferences | Year: 2015

Quantitative methods for evaluating and managing software security are becoming reliable with the ever increasing vulnerability datasets. The Common Vulnerability Scoring System (CVSS) provides a way to quantitatively evaluate individual vulnerability. However it cannot be applied to evaluate software risk directly and some metrics of CVSS are hard to assess. To overcome these shortcomings, this paper presents a novel method, which combines the CVSS base score with market share and software patches, to quantitatively evaluate the software risk. It is based on CVSS and includes three indicators: Absolute Severity Value (ASV), Relative Severity Value (RSV) and Severity Value Variation Rate (SVVR). Experimental results indicate that by using these indicators, the method can quantitatively describe the risk level of software systems, and thus strengthen software security. © 2015 Owned by the authors, published by EDP Sciences.

Bu N.,China Information Security Certification Center | Liu Y.,Information Assurance | Lian Y.,Information Assurance | Huang L.,Information Assurance
Jisuanji Yanjiu yu Fazhan/Computer Research and Development | Year: 2014

Under the guidance of existing laws, regulations and standards, a general framework of network security infrastructure is proposed. The proposed infrastructure discusseds the relations between security objectives, security boundary, security infrastructure elements and security risk assessment. Based on this infrastructure, we present our modeling approaches of security objectives, security boundary and security infrastructure elements using UML's standard and powerful modeling ability. Our modeling methods can eliminate the ambiguity in communication and make the representation of security system be standardized. Using our analysis methods, security administrators can validate how the business processes meet to the business goals and get the security risk of the system. By modeling an online banking, the proposed security framework and modeling methods' validity and rationality are verified. The proposed approach can help security administrators model the network security system in a visualization method. Based on modal logic, security administrators can deduce the logical relationships between each element and the results can guide security administrators to deploy proper security measures. Compared with the existing methods, the method of this paper is more comprehensive and has stronger guiding significance.

Yang M.,Beihang University | Duan S.,Beihang University | Duan J.,China Information Security Certification Center | Wang X.,Beihang University | And 3 more authors.
Journal of X-Ray Science and Technology | Year: 2013

Fast-continuous-rotation is an effective measure to improve the scanning speed and decrease the radiation dose for cone-beam CT. However, because of acceleration and deceleration of the motor, as well as the response lag of the scanning control terminals to the host PC, uneven-distributed and redundant projections are inevitably created, which seriously decrease the quality of the reconstruction images. In this paper, we first analyzed the aspects of the theoretical sequence chart of the fast-continuous-rotation mode. Then, an optimized sequence chart was proposed by extending the rotation angle span to ensure the effective 2π-span projections were situated in the stable rotation stage. In order to match the rotation angle with the projection image accurately, structure similarity (SSIM) index was used as a control parameter for extraction of the effective projection sequence which was exactly the complete projection data for image reconstruction. The experimental results showed that SSIM based method had a high accuracy of projection view locating and was easy to realize. © 2013 IOS Press and the authors.

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