The paper presents a novel benefit based query processing strategy for efficient query routing. Based on DHT as the overlay network, it first applies Nash equilibrium to construct the optimal peer group based on the c...The paper presents a novel benefit based query processing strategy for efficient query routing. Based on DHT as the overlay network, it first applies Nash equilibrium to construct the optimal peer group based on the correlations of keywords and coverage and overlap of the peers to decrease the time cost, and then presents a two-layered architecture for query processing that utilizes Bloom filter as compact representation to reduce the bandwidth consumption. Extensive experiments conducted on a real world dataset have demonstrated that our approach obviously decreases the processing time, while improves the precision and recall as well.展开更多
A finite element model of vehicle and its airbag landing attenuation system is established and verified experimentally.Two design cases are selected to constrain the airbag design for extreme landing conditions,while ...A finite element model of vehicle and its airbag landing attenuation system is established and verified experimentally.Two design cases are selected to constrain the airbag design for extreme landing conditions,while the height and width of airbag and the area of vent hole are chosen as design variables.The optimization is forced to compromise the design variables between the conflicting requirements of the two extremes.In order to optimize the parameters of airbag,the multi-dimensional response surfaces based on extended Latin hypercube design and radial basis function are employed instead of the complex finite element model.Pareto optimal solution sets based on response surfaces are then obtained by multi-objective genetic algorithm.The results show the optimization method presented in this paper is a practical tool for the optimization of airbag landing attenuation system for heavy airdrop.展开更多
用户在租赁了云服务提供商(Cloud Service Provider,CSP)的存储空间之后,为了保护隐私,通常将文件以密文的形式存储在CSP上。这给在密文数据上进行关键词查找带来了问题。在本应用场景中,CSP被视为潜在攻击者。提出了支持多关键词查找...用户在租赁了云服务提供商(Cloud Service Provider,CSP)的存储空间之后,为了保护隐私,通常将文件以密文的形式存储在CSP上。这给在密文数据上进行关键词查找带来了问题。在本应用场景中,CSP被视为潜在攻击者。提出了支持多关键词查找的安全高效的云计算方案。该方案基于二叉排序树结构,在保证用户数据的安全和隐私的前提下,支持授权用户对文件的多关键词查询,让用户可以随时随地享受多关键词查询服务。展开更多
基金Supported by the National Natural Science Foundation of China (60673139, 60473073, 60573090)
文摘The paper presents a novel benefit based query processing strategy for efficient query routing. Based on DHT as the overlay network, it first applies Nash equilibrium to construct the optimal peer group based on the correlations of keywords and coverage and overlap of the peers to decrease the time cost, and then presents a two-layered architecture for query processing that utilizes Bloom filter as compact representation to reduce the bandwidth consumption. Extensive experiments conducted on a real world dataset have demonstrated that our approach obviously decreases the processing time, while improves the precision and recall as well.
文摘A finite element model of vehicle and its airbag landing attenuation system is established and verified experimentally.Two design cases are selected to constrain the airbag design for extreme landing conditions,while the height and width of airbag and the area of vent hole are chosen as design variables.The optimization is forced to compromise the design variables between the conflicting requirements of the two extremes.In order to optimize the parameters of airbag,the multi-dimensional response surfaces based on extended Latin hypercube design and radial basis function are employed instead of the complex finite element model.Pareto optimal solution sets based on response surfaces are then obtained by multi-objective genetic algorithm.The results show the optimization method presented in this paper is a practical tool for the optimization of airbag landing attenuation system for heavy airdrop.
文摘用户在租赁了云服务提供商(Cloud Service Provider,CSP)的存储空间之后,为了保护隐私,通常将文件以密文的形式存储在CSP上。这给在密文数据上进行关键词查找带来了问题。在本应用场景中,CSP被视为潜在攻击者。提出了支持多关键词查找的安全高效的云计算方案。该方案基于二叉排序树结构,在保证用户数据的安全和隐私的前提下,支持授权用户对文件的多关键词查询,让用户可以随时随地享受多关键词查询服务。