An improved safety analysis based on the causality diagram for the complex system of micro aero-engines is presented.The study is examined by using the causality diagram in analytical failure cases due to rupture or p...An improved safety analysis based on the causality diagram for the complex system of micro aero-engines is presented.The study is examined by using the causality diagram in analytical failure cases due to rupture or pentration in the receiver of micro turbojet engine casing,and the comparisons are also made with the results from the traditional fault tree analysis.Experimental results show two main advantages：（1）Quantitative analysis which is more reliable for the failure analysis in jet engines can be produced by the causality diagram analysis;（2）Graphical representation of causality diagram is easier to apply in real test cases and more effective for the safety assessment.展开更多
联合解密与指纹嵌入(joint fingerprinting and decryption,JFD)框架能为遥感影像的安全分发提供完整的安全保护,且效率较高。但这种方案不仅导致指纹嵌入后的图像质量下降较为明显,且不能满足遥感影像的近无损性的要求。针对JFD框架的...联合解密与指纹嵌入(joint fingerprinting and decryption,JFD)框架能为遥感影像的安全分发提供完整的安全保护,且效率较高。但这种方案不仅导致指纹嵌入后的图像质量下降较为明显,且不能满足遥感影像的近无损性的要求。针对JFD框架的这种缺陷,本文提出了一种基于内容的遥感影像安全分发方法,对遥感影像根据内容进行分类,选取对遥感影像内容影响较小的区域嵌入指纹;提出邻域相似度的定义,选取加密后邻域相关性保持较好的区域进行部分解密,嵌入指纹。实验结果表明,利用本文提出的方案获得的嵌入指纹后的图像质量较好,且不影响遥感影像的后续应用。展开更多
作为一种新型的数字版权保护技术,数字指纹通过在出售给每个消费者的数字拷贝中秘密地嵌入一个唯一的序列码来实现版权保护与盗版者追踪的目的。一旦发现未授权的数字拷贝时,内容提供商能够通过所提取到的序列码追踪到相应的盗版者。提...作为一种新型的数字版权保护技术,数字指纹通过在出售给每个消费者的数字拷贝中秘密地嵌入一个唯一的序列码来实现版权保护与盗版者追踪的目的。一旦发现未授权的数字拷贝时,内容提供商能够通过所提取到的序列码追踪到相应的盗版者。提出了一种多媒体指纹方案,其中IPP(identifi able parent property)码被用来构造消费者的序列码,以抵抗多个消费者之间的合谋攻击。实验结果表明,该方案具有较好的抗合谋性能。展开更多
By leveraging the 5G enabled vehicular ad hoc network(5G-VANET), it is widely recognized that connected vehicles have the potentials to improve road safety, transportation intelligence and provide in-vehicle entertain...By leveraging the 5G enabled vehicular ad hoc network(5G-VANET), it is widely recognized that connected vehicles have the potentials to improve road safety, transportation intelligence and provide in-vehicle entertainment experience. However, many enabling applications in 5G-VANET rely on the efficient content sharing among mobile vehicles, which is a very challenging issue due to the extremely large data volume, rapid topology change, and unbalanced traffic. In this paper, we investigate content prefetching and distribution in 5G-VANET. We first introduce an edge computing based hierarchical architecture for efficient distribution of large-volume vehicular data. We then propose a multi-place multi-factor prefetching scheme to meet the rapid topology change and unbalanced traffic. The content requests of vehicles can be served by neighbors, which can improve the sharing efficiency and alleviate the burden of networks. Furthermore, we use a graph theory based approach to solve the content distribution by transforming it into a maximum weighted independent set problem. Finally, the proposed scheme is evaluated with a greedy transmission strategy to demonstrate its efficiency.展开更多
文摘An improved safety analysis based on the causality diagram for the complex system of micro aero-engines is presented.The study is examined by using the causality diagram in analytical failure cases due to rupture or pentration in the receiver of micro turbojet engine casing,and the comparisons are also made with the results from the traditional fault tree analysis.Experimental results show two main advantages：（1）Quantitative analysis which is more reliable for the failure analysis in jet engines can be produced by the causality diagram analysis;（2）Graphical representation of causality diagram is easier to apply in real test cases and more effective for the safety assessment.
文摘联合解密与指纹嵌入(joint fingerprinting and decryption,JFD)框架能为遥感影像的安全分发提供完整的安全保护,且效率较高。但这种方案不仅导致指纹嵌入后的图像质量下降较为明显,且不能满足遥感影像的近无损性的要求。针对JFD框架的这种缺陷,本文提出了一种基于内容的遥感影像安全分发方法,对遥感影像根据内容进行分类,选取对遥感影像内容影响较小的区域嵌入指纹;提出邻域相似度的定义,选取加密后邻域相关性保持较好的区域进行部分解密,嵌入指纹。实验结果表明,利用本文提出的方案获得的嵌入指纹后的图像质量较好,且不影响遥感影像的后续应用。
文摘作为一种新型的数字版权保护技术,数字指纹通过在出售给每个消费者的数字拷贝中秘密地嵌入一个唯一的序列码来实现版权保护与盗版者追踪的目的。一旦发现未授权的数字拷贝时,内容提供商能够通过所提取到的序列码追踪到相应的盗版者。提出了一种多媒体指纹方案,其中IPP(identifi able parent property)码被用来构造消费者的序列码,以抵抗多个消费者之间的合谋攻击。实验结果表明,该方案具有较好的抗合谋性能。
基金the support of National Science and Technology Major Project of the Ministry of Science and Technology of China under Grant No.2016ZX03001025003the Natural Science Foundation of Beijing under Grant No.4181002+2 种基金the Natural Science Foundation of China under Grant No.91638204BUPT Excellent Ph.D. Students Foundation under Grant No.CX2018210Natural Sciences and Engineering Research Council (NSERC),Canada
文摘By leveraging the 5G enabled vehicular ad hoc network(5G-VANET), it is widely recognized that connected vehicles have the potentials to improve road safety, transportation intelligence and provide in-vehicle entertainment experience. However, many enabling applications in 5G-VANET rely on the efficient content sharing among mobile vehicles, which is a very challenging issue due to the extremely large data volume, rapid topology change, and unbalanced traffic. In this paper, we investigate content prefetching and distribution in 5G-VANET. We first introduce an edge computing based hierarchical architecture for efficient distribution of large-volume vehicular data. We then propose a multi-place multi-factor prefetching scheme to meet the rapid topology change and unbalanced traffic. The content requests of vehicles can be served by neighbors, which can improve the sharing efficiency and alleviate the burden of networks. Furthermore, we use a graph theory based approach to solve the content distribution by transforming it into a maximum weighted independent set problem. Finally, the proposed scheme is evaluated with a greedy transmission strategy to demonstrate its efficiency.
