In this paper,we propose a Multi-token Sector Antenna Neighbor Discovery(M-SAND)protocol to enhance the efficiency of neighbor discovery in asynchronous directional ad hoc networks.The central concept of our work invo...In this paper,we propose a Multi-token Sector Antenna Neighbor Discovery(M-SAND)protocol to enhance the efficiency of neighbor discovery in asynchronous directional ad hoc networks.The central concept of our work involves maintaining multiple tokens across the network.To prevent mutual interference among multi-token holders,we introduce the time and space non-interference theorems.Furthermore,we propose a master-slave strategy between tokens.When the master token holder(MTH)performs the neighbor discovery,it decides which 1-hop neighbor is the next MTH and which 2-hop neighbors can be the new slave token holders(STHs).Using this approach,the MTH and multiple STHs can simultaneously discover their neighbors without causing interference with each other.Building on this foundation,we provide a comprehensive procedure for the M-SAND protocol.We also conduct theoretical analyses on the maximum number of STHs and the lower bound of multi-token generation probability.Finally,simulation results demonstrate the time efficiency of the M-SAND protocol.When compared to the QSAND protocol,which uses only one token,the total neighbor discovery time is reduced by 28% when 6beams and 112 nodes are employed.展开更多
针对传统的RBAC模型不能表达复杂的工作流安全访问控制约束的缺点,提出了一个适合工作流系统的基于多权角色和规则的条件化安全访问控制模型CMWRRBSAC(conditioned multi-weighted role and rule based secure access control model)。...针对传统的RBAC模型不能表达复杂的工作流安全访问控制约束的缺点,提出了一个适合工作流系统的基于多权角色和规则的条件化安全访问控制模型CMWRRBSAC(conditioned multi-weighted role and rule based secure access control model)。该模型基于传统的RBAC模型,提出了基于动态角色分配的条件化RBAC方法,定义了基于多权角色的工作流系统访问授权新概念,并针对多个角色和多个用户协同激活任务的序约束问题,给出了基于令牌的序约束算法和基于加权角色综合的序约束算法,讨论了一个基于规则的职责分离约束建模方法,并给出了改进的规则一致性检验算法。展开更多
构建农业水资源可持续利用(Sustainable Utilization of Agricultural Water Re-sources,SUAWR)评价指标体系(Indicaters Systern,IS)既要考虑IS构建的一般性问题,也要顾及SUAWR内涵的多维性.根据SUAWR内涵,分别从用水流程和用水影响因...构建农业水资源可持续利用(Sustainable Utilization of Agricultural Water Re-sources,SUAWR)评价指标体系(Indicaters Systern,IS)既要考虑IS构建的一般性问题,也要顾及SUAWR内涵的多维性.根据SUAWR内涵,分别从用水流程和用水影响因素两种角度提出了SUAWR评价目的和评价要求,指出SUAWR评价维度包括质量维、数量维和时空维.在阐明评价理论基础上,提出IS构建原则,并采用频度统计法、理论分析法等方法,进行了IS构建、结构优化,并进行构成分析,建立了以农业可持续发展为目标的一般性SUAWR综合评价IS,探讨了AWR复合系统多维度可持续性评价如何在多层次IS中实现.展开更多
基金supported in part by the National Natural Science Foundations of CHINA(Grant No.61771392,No.61771390,No.61871322 and No.61501373)Science and Technology on Avionics Integration Laboratory and the Aeronautical Science Foundation of China(Grant No.201955053002 and No.20185553035)。
文摘In this paper,we propose a Multi-token Sector Antenna Neighbor Discovery(M-SAND)protocol to enhance the efficiency of neighbor discovery in asynchronous directional ad hoc networks.The central concept of our work involves maintaining multiple tokens across the network.To prevent mutual interference among multi-token holders,we introduce the time and space non-interference theorems.Furthermore,we propose a master-slave strategy between tokens.When the master token holder(MTH)performs the neighbor discovery,it decides which 1-hop neighbor is the next MTH and which 2-hop neighbors can be the new slave token holders(STHs).Using this approach,the MTH and multiple STHs can simultaneously discover their neighbors without causing interference with each other.Building on this foundation,we provide a comprehensive procedure for the M-SAND protocol.We also conduct theoretical analyses on the maximum number of STHs and the lower bound of multi-token generation probability.Finally,simulation results demonstrate the time efficiency of the M-SAND protocol.When compared to the QSAND protocol,which uses only one token,the total neighbor discovery time is reduced by 28% when 6beams and 112 nodes are employed.
文摘针对传统的RBAC模型不能表达复杂的工作流安全访问控制约束的缺点,提出了一个适合工作流系统的基于多权角色和规则的条件化安全访问控制模型CMWRRBSAC(conditioned multi-weighted role and rule based secure access control model)。该模型基于传统的RBAC模型,提出了基于动态角色分配的条件化RBAC方法,定义了基于多权角色的工作流系统访问授权新概念,并针对多个角色和多个用户协同激活任务的序约束问题,给出了基于令牌的序约束算法和基于加权角色综合的序约束算法,讨论了一个基于规则的职责分离约束建模方法,并给出了改进的规则一致性检验算法。
文摘构建农业水资源可持续利用(Sustainable Utilization of Agricultural Water Re-sources,SUAWR)评价指标体系(Indicaters Systern,IS)既要考虑IS构建的一般性问题,也要顾及SUAWR内涵的多维性.根据SUAWR内涵,分别从用水流程和用水影响因素两种角度提出了SUAWR评价目的和评价要求,指出SUAWR评价维度包括质量维、数量维和时空维.在阐明评价理论基础上,提出IS构建原则,并采用频度统计法、理论分析法等方法,进行了IS构建、结构优化,并进行构成分析,建立了以农业可持续发展为目标的一般性SUAWR综合评价IS,探讨了AWR复合系统多维度可持续性评价如何在多层次IS中实现.
