By analyzing the working principle of Linux network device driver,discussing the Linux network driver structure and its key technologies,the general network driver structure and its design methodologies in Linux syste...By analyzing the working principle of Linux network device driver,discussing the Linux network driver structure and its key technologies,the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull.c and improving the COW technology,the Zero-Copy technology in Linux (kernel version 2.6.11) is implemented. In the end,the success test tells us that the thorough analysis of network device driver is the foundation of many applications,and it also provides a certain improvement to a lot of real applications,even to military application development.展开更多
The objective of this research is to determine the effect earthquakes have on the performance of transportation network systems.To do this,bridge fragility curves,expressed as a function of peak ground acceleration(PG...The objective of this research is to determine the effect earthquakes have on the performance of transportation network systems.To do this,bridge fragility curves,expressed as a function of peak ground acceleration(PGA)and peak ground velocity(PGV),were developed.Network damage was evaluated under the 1994 Northridge earthquake and scenario earthquakes.A probabilistic model was developed to determine the effect of repair of bridge damage on the improvement of the network performance as days passed after the event.As an example,the system performance degradation measured in terms of an index,'Drivers Delay,'is calculated for the Los Angeles area transportation system,and losses due to Drivers Delay with and without retrofit were estimated.展开更多
文摘By analyzing the working principle of Linux network device driver,discussing the Linux network driver structure and its key technologies,the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull.c and improving the COW technology,the Zero-Copy technology in Linux (kernel version 2.6.11) is implemented. In the end,the success test tells us that the thorough analysis of network device driver is the foundation of many applications,and it also provides a certain improvement to a lot of real applications,even to military application development.
基金The Federal Highway Administration(FHWA)under Contract No.DTFH61-98-C-00094the California Department of Transportation(CALTRANS)
文摘The objective of this research is to determine the effect earthquakes have on the performance of transportation network systems.To do this,bridge fragility curves,expressed as a function of peak ground acceleration(PGA)and peak ground velocity(PGV),were developed.Network damage was evaluated under the 1994 Northridge earthquake and scenario earthquakes.A probabilistic model was developed to determine the effect of repair of bridge damage on the improvement of the network performance as days passed after the event.As an example,the system performance degradation measured in terms of an index,'Drivers Delay,'is calculated for the Los Angeles area transportation system,and losses due to Drivers Delay with and without retrofit were estimated.
