Physical layer security is an emerging technique for improving wireless communication security, which is widely regarded as a complement to cryptographic technologies. To design physical layer security techniques for ...Physical layer security is an emerging technique for improving wireless communication security, which is widely regarded as a complement to cryptographic technologies. To design physical layer security techniques for practical scenarios, uncertainty and imperfections in the channel knowledge need to be taken into account. This paper is a survey of recent research on physical layer security that considers imperfect channel state information （CSI） at communication nodes. We first give an overview of the main information-theoretic measures of secrecy performance with imperfect CSI. Then, we describe several signal processing enhancements in secure transmission designs. These enhancements include secure on-off transmission, beamforming with artificial noise, and secure communication assisted by relay nodes or in cognitive radio systems. Recent studies of physical layer security in large-scale decentralized wireless networks are also summarized. Finally, open problems for on-going and future research are discussed.展开更多
随着信息技术的快速发展,建筑信息模型(Building Information Modeling,BIM)在建筑行业中的应用日益广泛。本论文针对路桥项目的特殊性,以解决实际问题为目标,探讨了BIM在路桥项目管理与协调中的应用[1]。通过对实际项目的案例研究,提...随着信息技术的快速发展,建筑信息模型(Building Information Modeling,BIM)在建筑行业中的应用日益广泛。本论文针对路桥项目的特殊性,以解决实际问题为目标,探讨了BIM在路桥项目管理与协调中的应用[1]。通过对实际项目的案例研究,提出了一套基于BIM的路桥项目管理与协调的方法和工具,以优化项目的生命周期管理和提高项目的整体效率。本研究为路桥项目的实际应用提供了有益的参考和指导。展开更多
The rapid development of the digital economy has provided a new impetus for rural residents to extend their working hours.Based on the data collected by the China Labor-force Dynamics Survey(CLDS)in 2014,2016,and 2018...The rapid development of the digital economy has provided a new impetus for rural residents to extend their working hours.Based on the data collected by the China Labor-force Dynamics Survey(CLDS)in 2014,2016,and 2018,this paper measured the development level of the digital economy in China from the perspectives of internet development and digital financial inclusion,and tested the mechanisms of how the digital economy affected rural residents’working hours.The results showed that the digital economy extended rural residents’working hours by expanding information channels and enhancing human capital,and this mechanism was affected by heterogeneity in rural residents’educational background,age,and social capital.Building on these findings,this paper holds that to increase rural residents’income by extending their working hours and achieving common prosperity for all,it is necessary to expand the opportunities for rural residents to participate in skills training and promote their accumulation of human capital.展开更多
文摘Physical layer security is an emerging technique for improving wireless communication security, which is widely regarded as a complement to cryptographic technologies. To design physical layer security techniques for practical scenarios, uncertainty and imperfections in the channel knowledge need to be taken into account. This paper is a survey of recent research on physical layer security that considers imperfect channel state information （CSI） at communication nodes. We first give an overview of the main information-theoretic measures of secrecy performance with imperfect CSI. Then, we describe several signal processing enhancements in secure transmission designs. These enhancements include secure on-off transmission, beamforming with artificial noise, and secure communication assisted by relay nodes or in cognitive radio systems. Recent studies of physical layer security in large-scale decentralized wireless networks are also summarized. Finally, open problems for on-going and future research are discussed.
文摘随着信息技术的快速发展,建筑信息模型(Building Information Modeling,BIM)在建筑行业中的应用日益广泛。本论文针对路桥项目的特殊性,以解决实际问题为目标,探讨了BIM在路桥项目管理与协调中的应用[1]。通过对实际项目的案例研究,提出了一套基于BIM的路桥项目管理与协调的方法和工具,以优化项目的生命周期管理和提高项目的整体效率。本研究为路桥项目的实际应用提供了有益的参考和指导。
基金This paper is part of the Youth Program of Science and Technology Research of Chongqing Municipal Education Commission(KJQN202300545)Youth Program of National Social Science Fund of China(21CJY001)Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN202300567).
文摘The rapid development of the digital economy has provided a new impetus for rural residents to extend their working hours.Based on the data collected by the China Labor-force Dynamics Survey(CLDS)in 2014,2016,and 2018,this paper measured the development level of the digital economy in China from the perspectives of internet development and digital financial inclusion,and tested the mechanisms of how the digital economy affected rural residents’working hours.The results showed that the digital economy extended rural residents’working hours by expanding information channels and enhancing human capital,and this mechanism was affected by heterogeneity in rural residents’educational background,age,and social capital.Building on these findings,this paper holds that to increase rural residents’income by extending their working hours and achieving common prosperity for all,it is necessary to expand the opportunities for rural residents to participate in skills training and promote their accumulation of human capital.
