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Bacthing Auditing of Data in Multicloud Storage
Zhihua Xia,Xinhui Wang,Xingming Sun,Yafeng Zhu,Peng Ji,Jin Wang 보안공학연구지원센터 2014 International Journal of Database Theory and Appli Vol.7 No.6
Cloud storage enables users to outsource their data to cloud servers and enjoy the on-demand services. However, this new paradigm also introduces integrity threats toward user’ outsourced data. This paper develops an efficient auditing mechanism, which support batch auditing for multiple data files in multi-cloud environment. By constructing a sequence-enforced Merkle Hash Tree, the proposed protocol can resist the replace attack. By using the bilinear map, the proposed protocol achieves stateless and transparent verification. By putting the computation of intermediate values of the verification on cloud servers, our method can greatly reduce the computing burden of the auditor. The performance analysis proves the good efficiency of the proposed protocol.
Zhihua Chen,Zhongwei Zhao,Han Zhu,Xiaodun Wang,Xiangyu Yan 한국강구조학회 2015 International Journal of Steel Structures Vol.15 No.2
Long-span spatial structures have advantages over other structural systems in terms of novelty and aesthetics in architectural form. However, the complexity of stress distribution causes these kinds of structures to change significantly between the construction and utilization stages. One-time loading method was used in the traditional design method to calculate and evaluate structural stress and structural deflection, either of which could cause problems in component size and residual stress during construction process. Therefore, construction simulation analysis of these structures must be performed. Element birth and death technology and step-by-step model technology (SSMT) are the main approaches in the finite element method used in construction analysis. This paper proposes a theory basis for the SSMT that was used in the constructional analysis of the Yujiapu Railway Station Building. Results obtained by the proposed method were compared with those by element birth and death technology. In addition, the preset construction deformation value was calculated to validate the correctness and efficiency of the proposed method.
Shiquan Zhu,Zhihua Chen,Hui Zhang,Zhen-gui Huang,Huanhao Zhang 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.5
To ensure the safe separation process of a missile from internal weapons bay, the control device is mounted in front of the internal weapons bay to control the separation process. Based on the coupling of Navier-Stokes (N-S) equations and six-degrees-of-freedom (6DOF) rigid-body motion equations, the separation process of missile under four different conditions (free separation, and rectangle, prism and wedge control) was numerically simulated. The separation process and flow fields were obtained, the aerodynamic parameters and trajectory parameters of four cases compared. Our results show that, the control device can improve the aerodynamic characteristics of the flow field, enhancing the safety of the missile separation. The wedge control device has the best control effect and makes the missile stable, the rectangular and prism control devices have strong bow shock wave and make the pitch angle of the missile large.
Secure Similarity Search over Encrypted Cloud Images
Yi Zhu,Xingming Sun,Zhihua Xia,Naixue Xiong 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.8
With the growing popularity of cloud computing, more and more data owners are willing to outsource their data to the cloud. However, private data should be encrypted before outsourcing for security requirements, which obsoletes data utilization like content-based image retrieval. In this paper, we propose a secure similarity image search scheme, which allows data owners to outsource their encrypted image database to the cloud server without revealing the real content of images. The proposed scheme supports both global and local feature based image retrieval under various distance metrics, such as earth mover's distance. Firstly, the data owner extracts either global features or local features from images to represent the images. Then, these features are used to generate a searchable index. Finally, both image database and searchable index are encrypted before outsourcing to the cloud server. When a query image coming, the data user extracts feature from the query image and generates the search trapdoor. The trapdoor is then sent to the cloud server and used to compare the similarity with the searchable index. Extensive experiments are conducted to show the efficiency and applicability of our proposed similarity image search system.
Dynamic Behavior of Rock Joint Under Different Impact Loads
Nan Wu,Zhen-de Zhu,Cong Zhang,Zhihua Luo 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.2
In order to investigate the influence of the rock joint to rock mass on dynamic loading, the Split Hopkinson Pressure Bar (SHPB) apparatus is used as an effective instrument. Using three different samples of intact (Series A), unfilled joint (Series B), and filled joint (Series C) interfaces, impact tests were performed under different impact speeds. Results showed that the peak strength of series B and C was 55%–75% that of series A. Series C was 10%–20% lower than series B because the former was filled with gypsum in the interface. The attenuation law of the transmission coefficient and failure mode caused by the rock joint was also obtained. To address the problem of classic rock joint constitutive relations being unsuitable under dynamic loading, a new regular expression is proposed by defining two velocity impact factors at respective impact velocities of 3.6 m/s, 6.6 m/s, and 9.6 m/s. Calculation results of this function are tested and verified, and the data are highly consistent.
Zhao, Shankai,Zhong, Feng,Zhu, Zhihua 한국분석과학회 1995 분석과학 Vol.8 No.4
The method of matrix-assisted laser desorption ionization mass spectrometry has been used to solve some bioanalytical problems, which is difficult to analyse by general methods. For the selection of proper laser wavelength and matrices, eight matriees was used with laser wavelength of 226 and 355nm. The result shows that with wavelength of 355nm better results could be obtained with most of the matrices. The molecular weight of eytochrome C, which was seperated by gel electrophoresis and electro-blotted onto NC membrane is determined by MALDI. The accuracy is better than 0.1%, which is much higher than that of SDS-PAGE. Protein mixture extracted from crude peanut oil is directly determined by MALDI. The molecuiar weight of its three components are determined, and the result also demonstrated that these proteins are in free manner. As proteins arc in 2S bond, with the traditional method, SDS-PAGE, it is not able to decide whether protein exists in combination mode or in free manner. In the technique of two phase aquesous solution, which is used for separating biomaterials, water soluble polymers stained with dyes are used in this technique. By the use of MALDI the number or the dye molecules react with the polymer PEG molecule are determined, and that is difficult to determined by other methods.