To increase airspace capacity, alleviate flight delay,and improve network robustness, an optimization method of multi-layer air transportation networks is put forward based on Laplacian energy maximization. The effect...To increase airspace capacity, alleviate flight delay,and improve network robustness, an optimization method of multi-layer air transportation networks is put forward based on Laplacian energy maximization. The effectiveness of taking Laplacian energy as a measure of network robustness is validated through numerical experiments. The flight routes addition optimization model is proposed with the principle of maximizing Laplacian energy. Three methods including the depth-first search( DFS) algorithm, greedy algorithm and Monte-Carlo tree search( MCTS) algorithm are applied to solve the proposed problem. The trade-off between system performance and computational efficiency is compared through simulation experiments. Finally, a case study on Chinese airport network( CAN) is conducted using the proposed model. Through encapsulating it into multi-layer infrastructure via k-core decomposition algorithm, Laplacian energy maximization for the sub-networks is discussed which can provide a useful tool for the decision-makers to optimize the robustness of the air transportation network on different scales.展开更多
Modernization of armies is a constant process and is driven by intuitive fact that those who do not modernize will become extinct. In last five decades, the development of modern armies has taken place around Colonel ...Modernization of armies is a constant process and is driven by intuitive fact that those who do not modernize will become extinct. In last five decades, the development of modern armies has taken place around Colonel John Boyd’s theory of OODA loop that deals with information superiority. Building a robust, mobile and capable network that could provide for novel appliances and information superiority is the main challenge which modernizers are facing. Network, suitable for future combat operations, and able to transport a vast amount of information on a battlefield, is expensive to build. Every mistake in design and the need to correct those mistakes could halt development in an army for years. Therefore, system dependability analysis during system design phase is needed. In this report, the concept of a future Battle Network System is described. The Report evaluates operational environment of BNS and possible failure reasons of the service, and illustrates the change in BNS Quality of Service due to probable transport layer errors. This paper describes the method of testing the concept of proposed network systems on the drawing board, and emphasizes design points for a new system. Nevertheless, the proposed method is by no means conclusive. Rather, it describes an engineering approach to define the main problems while creating MANET-based networking systems.展开更多
Buses and subways are essential to urban public transportation systems and an important engine for activating high-quality urban development. Traditional multi-modal transportation networks focus on the structural fea...Buses and subways are essential to urban public transportation systems and an important engine for activating high-quality urban development. Traditional multi-modal transportation networks focus on the structural feature mining of single-layer networks or each layer, ignoring the structural association of multi-layer networks. In this paper, we examined the multi-layer structural property of the bus-subway network of Shanghai at both global and nodal scales. A dual-layer model of the city’s bus and subway system was built. Single-layer complex network indicators were also extended. The paper also explored the spatial coupling properties of the city’s bus and subway system and identified its primary traffic nodes. It was found that 1) the dual-layer network increased the network’s connectivity to a certain extent and broke through the spatial limitation in terms of physical structure, making the connection between any two locations more direct. 2) The dual-layer network changed the topological characteristics of the transit network, increasing the centrality value and bit order in degree centrality, betweenness centrality, and closeness centrality to different degrees, and making each centrality tend to converge to the city center in spatial distribution. Enhancing the management of critical network nodes would help the integrated public transportation system operate more effectively and provide higher-quality services.展开更多
In this paper, we have proved the diminution in error approximation when identity authentication is done with Ideal Password Authentication Scheme (IPAS) for Network Security. Effectiveness of identity authentication ...In this paper, we have proved the diminution in error approximation when identity authentication is done with Ideal Password Authentication Scheme (IPAS) for Network Security. Effectiveness of identity authentication parameters for various attacks and security requirements is verified in the paper. Result of analysis proves that IPAS would enhance the transport layer security. Proof of efficiency of result is generated with drastic diminution in error approximation. IPAS would have advanced security parameters with implemented RNA-FINNT which would result in fortification of the transport layer security protocol for enhancement of Network Security.展开更多
DNS over HTTPS(DoH)协议是一种针对域名系统(DNS)的最新改进方案,然而用户可使用第三方DoH服务规避内网原有的监管,所以异常流量检测方法不再适用于检测DoH流量。针对该问题提出了一种DTESI算法。首先,基于信息熵将DoH流量作为异常流...DNS over HTTPS(DoH)协议是一种针对域名系统(DNS)的最新改进方案,然而用户可使用第三方DoH服务规避内网原有的监管,所以异常流量检测方法不再适用于检测DoH流量。针对该问题提出了一种DTESI算法。首先,基于信息熵将DoH流量作为异常流量从全部网络流量中筛选出来;然后,利用DoH服务器与同一客户端建立TLS连接时响应方式总是相同的特性,用指纹识别检测客户端与DoH服务器之间的TLS协商,确定DoH服务器身份;最后,使用Top-K抽样算法选出一定时段内网络中前K台活跃主机着重进行流量检测,使算法能应用于中大型组织的网络。实验结果表明,针对发现的异常流量,DTESI算法检测出的DoH服务提供商准确率超过94%。在此基础上比较了在不同K值下的算法检测时间和对网络中全部DoH流量的检测覆盖率,结果表明合理选择K值可以提升算法的整体效能。展开更多
针对空间数据传输与交互支持问题,介绍了CCSDS(Consultative Committee for Space Data Systems,空间数据系统咨询委员会)、IOAG/IOP(Interagency Operations Advisory Group/InterOperability Plenary,机构间操作指导组/机构间互操作大...针对空间数据传输与交互支持问题,介绍了CCSDS(Consultative Committee for Space Data Systems,空间数据系统咨询委员会)、IOAG/IOP(Interagency Operations Advisory Group/InterOperability Plenary,机构间操作指导组/机构间互操作大会),以及IETF/IRTF(Internet Engineering Task Force/Internet Research Task Force,互联网工程任务组/互联网研究任务组)在空间网络体系架构方面的研究进展,分析了IETF和CCSDS针对空间网络环境所发布的最新网络层协议和传输层协议。研究结果表明,IP(Internet Protocol,互联网协议)和DTN(Delay Tolerant Networking,容延迟网络)是空间网络协议体系的2个发展方向,而空间网络技术则呈现出3个清晰的发展趋势,现阶段需要重点关注路由、服务质量保证和数据流传输这3个方面的技术问题。展开更多
针对西安市道路网矢量源数据,从定性的角度提出了城市道路网的分层依据,实现了西安市道路网的分层,完成了分层道路网数据向Oracle空间数据库的加载,总结了基于OO4O(Oracle objects for ole)接口访问道路网空间数据库的技术要点,阐释了...针对西安市道路网矢量源数据,从定性的角度提出了城市道路网的分层依据,实现了西安市道路网的分层,完成了分层道路网数据向Oracle空间数据库的加载,总结了基于OO4O(Oracle objects for ole)接口访问道路网空间数据库的技术要点,阐释了典型例程,为设计和实现基于空间数据库的分层路径寻优算法奠定了基础。展开更多
基金The National Natural Science Foundation of China(No.61573098,71401072)the Natural Science Foundation of Jiangsu Province(No.BK20130814)
文摘To increase airspace capacity, alleviate flight delay,and improve network robustness, an optimization method of multi-layer air transportation networks is put forward based on Laplacian energy maximization. The effectiveness of taking Laplacian energy as a measure of network robustness is validated through numerical experiments. The flight routes addition optimization model is proposed with the principle of maximizing Laplacian energy. Three methods including the depth-first search( DFS) algorithm, greedy algorithm and Monte-Carlo tree search( MCTS) algorithm are applied to solve the proposed problem. The trade-off between system performance and computational efficiency is compared through simulation experiments. Finally, a case study on Chinese airport network( CAN) is conducted using the proposed model. Through encapsulating it into multi-layer infrastructure via k-core decomposition algorithm, Laplacian energy maximization for the sub-networks is discussed which can provide a useful tool for the decision-makers to optimize the robustness of the air transportation network on different scales.
文摘Modernization of armies is a constant process and is driven by intuitive fact that those who do not modernize will become extinct. In last five decades, the development of modern armies has taken place around Colonel John Boyd’s theory of OODA loop that deals with information superiority. Building a robust, mobile and capable network that could provide for novel appliances and information superiority is the main challenge which modernizers are facing. Network, suitable for future combat operations, and able to transport a vast amount of information on a battlefield, is expensive to build. Every mistake in design and the need to correct those mistakes could halt development in an army for years. Therefore, system dependability analysis during system design phase is needed. In this report, the concept of a future Battle Network System is described. The Report evaluates operational environment of BNS and possible failure reasons of the service, and illustrates the change in BNS Quality of Service due to probable transport layer errors. This paper describes the method of testing the concept of proposed network systems on the drawing board, and emphasizes design points for a new system. Nevertheless, the proposed method is by no means conclusive. Rather, it describes an engineering approach to define the main problems while creating MANET-based networking systems.
文摘Buses and subways are essential to urban public transportation systems and an important engine for activating high-quality urban development. Traditional multi-modal transportation networks focus on the structural feature mining of single-layer networks or each layer, ignoring the structural association of multi-layer networks. In this paper, we examined the multi-layer structural property of the bus-subway network of Shanghai at both global and nodal scales. A dual-layer model of the city’s bus and subway system was built. Single-layer complex network indicators were also extended. The paper also explored the spatial coupling properties of the city’s bus and subway system and identified its primary traffic nodes. It was found that 1) the dual-layer network increased the network’s connectivity to a certain extent and broke through the spatial limitation in terms of physical structure, making the connection between any two locations more direct. 2) The dual-layer network changed the topological characteristics of the transit network, increasing the centrality value and bit order in degree centrality, betweenness centrality, and closeness centrality to different degrees, and making each centrality tend to converge to the city center in spatial distribution. Enhancing the management of critical network nodes would help the integrated public transportation system operate more effectively and provide higher-quality services.
文摘In this paper, we have proved the diminution in error approximation when identity authentication is done with Ideal Password Authentication Scheme (IPAS) for Network Security. Effectiveness of identity authentication parameters for various attacks and security requirements is verified in the paper. Result of analysis proves that IPAS would enhance the transport layer security. Proof of efficiency of result is generated with drastic diminution in error approximation. IPAS would have advanced security parameters with implemented RNA-FINNT which would result in fortification of the transport layer security protocol for enhancement of Network Security.
文摘DNS over HTTPS(DoH)协议是一种针对域名系统(DNS)的最新改进方案,然而用户可使用第三方DoH服务规避内网原有的监管,所以异常流量检测方法不再适用于检测DoH流量。针对该问题提出了一种DTESI算法。首先,基于信息熵将DoH流量作为异常流量从全部网络流量中筛选出来;然后,利用DoH服务器与同一客户端建立TLS连接时响应方式总是相同的特性,用指纹识别检测客户端与DoH服务器之间的TLS协商,确定DoH服务器身份;最后,使用Top-K抽样算法选出一定时段内网络中前K台活跃主机着重进行流量检测,使算法能应用于中大型组织的网络。实验结果表明,针对发现的异常流量,DTESI算法检测出的DoH服务提供商准确率超过94%。在此基础上比较了在不同K值下的算法检测时间和对网络中全部DoH流量的检测覆盖率,结果表明合理选择K值可以提升算法的整体效能。
文摘针对空间数据传输与交互支持问题,介绍了CCSDS(Consultative Committee for Space Data Systems,空间数据系统咨询委员会)、IOAG/IOP(Interagency Operations Advisory Group/InterOperability Plenary,机构间操作指导组/机构间互操作大会),以及IETF/IRTF(Internet Engineering Task Force/Internet Research Task Force,互联网工程任务组/互联网研究任务组)在空间网络体系架构方面的研究进展,分析了IETF和CCSDS针对空间网络环境所发布的最新网络层协议和传输层协议。研究结果表明,IP(Internet Protocol,互联网协议)和DTN(Delay Tolerant Networking,容延迟网络)是空间网络协议体系的2个发展方向,而空间网络技术则呈现出3个清晰的发展趋势,现阶段需要重点关注路由、服务质量保证和数据流传输这3个方面的技术问题。
文摘针对西安市道路网矢量源数据,从定性的角度提出了城市道路网的分层依据,实现了西安市道路网的分层,完成了分层道路网数据向Oracle空间数据库的加载,总结了基于OO4O(Oracle objects for ole)接口访问道路网空间数据库的技术要点,阐释了典型例程,为设计和实现基于空间数据库的分层路径寻优算法奠定了基础。
