As the maritime sector embraces more technology to increase efficiency, lower carbon emissions, and adapt to meet modern challenges, cyber and cyber-physical safety become a more significant issue. However, unfortunat...As the maritime sector embraces more technology to increase efficiency, lower carbon emissions, and adapt to meet modern challenges, cyber and cyber-physical safety become a more significant issue. However, unfortunately, much of past research view cyber-security issues in transportation as primarily information technology problems. This paper designs and uses a case study to illustrate how cyber-security and physical safety should be viewed together, cyber and physical (</span><i><span style="font-family:Verdana;">i.e.</span></i><span style="font-family:Verdana;"> cyber-physical), when considering ship-to-ship</span></span><span style="font-family:Verdana;"> and ship-to-shore interactions. While there is some scenario designing, this case study is built with real port data and ship systems to demonstrate a real-world cyber-attack on a ship. It shows plausible physical effects that affect the safety of those involved. This case study is also made realistic with a novel hybrid cyber range and hardware testbed environment, designed to examine the different effects a ship-based cyber-attack could potentially have on a port. This informs several solutions, technical and social, that could enhance cyber-physical safety in marine transportation.展开更多
目前市场上的三层交换机有2种方式可以配置交换机端口的IP地址,一是直接在物理端口上设置,二是通过逻辑VLAN端口间接设置。为了分析这2种配置方法在交换机实际运行中会产生哪些差别,在详细分析了三层交换机端口工作原理的基础上,搭建测...目前市场上的三层交换机有2种方式可以配置交换机端口的IP地址,一是直接在物理端口上设置,二是通过逻辑VLAN端口间接设置。为了分析这2种配置方法在交换机实际运行中会产生哪些差别,在详细分析了三层交换机端口工作原理的基础上,搭建测试环境,主要从端口初始化和三层路由收敛过程分析了2种方式的不同。通过分析发现,在交换机物理端口上直接配置IP地址,可以节省生成树协议(STP,Spanning Tree Protocol)收敛所需的时间,并且不需要规划额外的VLAN,为日后的运行维护工作带来了方便。展开更多
在长期演进（LTE）系统中,发送天线端口数通过循环冗余校验掩码的方式隐含于物理广播信道（PBCH）中,终端在解读PBCH信道获取主信息块（MIB）的同时,需要正确检测PBCH采用的发送天线端口数。传统的检测方法尝试分别用1、2、4等3种发射...在长期演进（LTE）系统中,发送天线端口数通过循环冗余校验掩码的方式隐含于物理广播信道（PBCH）中,终端在解读PBCH信道获取主信息块（MIB）的同时,需要正确检测PBCH采用的发送天线端口数。传统的检测方法尝试分别用1、2、4等3种发射天线数进行PBCH译码,直至正确译码为止,译码复杂度非常高。基于此,提出一种改进的天线端口数估计算法,提取各天线端口传输的小区参考信号序列做相关,通过相关值与相关系数门限值的比较直接快速获取基站的实际天线端口数。仿真结果表明：该算法相较于传统检测算法和功率检测算法在时间复杂度上分别提升了4个数量级和3倍;在信噪比高于0 d B时,所提检测算法较功率检测算法有4-6 d B的增益。展开更多
文摘As the maritime sector embraces more technology to increase efficiency, lower carbon emissions, and adapt to meet modern challenges, cyber and cyber-physical safety become a more significant issue. However, unfortunately, much of past research view cyber-security issues in transportation as primarily information technology problems. This paper designs and uses a case study to illustrate how cyber-security and physical safety should be viewed together, cyber and physical (</span><i><span style="font-family:Verdana;">i.e.</span></i><span style="font-family:Verdana;"> cyber-physical), when considering ship-to-ship</span></span><span style="font-family:Verdana;"> and ship-to-shore interactions. While there is some scenario designing, this case study is built with real port data and ship systems to demonstrate a real-world cyber-attack on a ship. It shows plausible physical effects that affect the safety of those involved. This case study is also made realistic with a novel hybrid cyber range and hardware testbed environment, designed to examine the different effects a ship-based cyber-attack could potentially have on a port. This informs several solutions, technical and social, that could enhance cyber-physical safety in marine transportation.
文摘目前市场上的三层交换机有2种方式可以配置交换机端口的IP地址,一是直接在物理端口上设置,二是通过逻辑VLAN端口间接设置。为了分析这2种配置方法在交换机实际运行中会产生哪些差别,在详细分析了三层交换机端口工作原理的基础上,搭建测试环境,主要从端口初始化和三层路由收敛过程分析了2种方式的不同。通过分析发现,在交换机物理端口上直接配置IP地址,可以节省生成树协议(STP,Spanning Tree Protocol)收敛所需的时间,并且不需要规划额外的VLAN,为日后的运行维护工作带来了方便。
文摘在长期演进（LTE）系统中,发送天线端口数通过循环冗余校验掩码的方式隐含于物理广播信道（PBCH）中,终端在解读PBCH信道获取主信息块（MIB）的同时,需要正确检测PBCH采用的发送天线端口数。传统的检测方法尝试分别用1、2、4等3种发射天线数进行PBCH译码,直至正确译码为止,译码复杂度非常高。基于此,提出一种改进的天线端口数估计算法,提取各天线端口传输的小区参考信号序列做相关,通过相关值与相关系数门限值的比较直接快速获取基站的实际天线端口数。仿真结果表明：该算法相较于传统检测算法和功率检测算法在时间复杂度上分别提升了4个数量级和3倍;在信噪比高于0 d B时,所提检测算法较功率检测算法有4-6 d B的增益。
