针对虚拟机(virtual machine,VM)在不同子网间进行在线迁移时,因网络接入点发生改变而无法继续通信的问题,设计和实现了基于代理移动IP(proxy mobile IP,PMIP)的网络连接重定向系统。当VM迁移到外部子网时,将其看做移动节点,不改变IP地...针对虚拟机(virtual machine,VM)在不同子网间进行在线迁移时,因网络接入点发生改变而无法继续通信的问题,设计和实现了基于代理移动IP(proxy mobile IP,PMIP)的网络连接重定向系统。当VM迁移到外部子网时,将其看做移动节点,不改变IP地址,通过外部网络和家乡网络之间的双向隧道传输所有来自和发往该VM的网络数据。此方案中跨子网的在线迁移行为对VM以及与VM通信的节点透明。实验证明了该系统可以保证VM较快的网络切换速度和较好的网络通信性能。展开更多
In order to overcome the disadvantages of diagonal connection structures that are complex and for which it is difficult to derive the discriminant of the airflow directions of airways, we have applied a multiple regre...In order to overcome the disadvantages of diagonal connection structures that are complex and for which it is difficult to derive the discriminant of the airflow directions of airways, we have applied a multiple regression method to analyze the effect, of changing the rules of mine airflows, on the stability of a mine ventilation system. The amount of air （ Qj ） is determined for the major airway and an optimum regression equation was derived for Qi as a function of the independent variable （ Ri ）, i.e., the venti- lation resistance between different airways. Therefore, corresponding countermeasures are proposed according to the changes in airflows. The calculated results agree very well with our practical situation, indicating that multiple regression analysis is simple, quick and practical and is therefore an effective method to analyze the stability of mine ventilation systems.展开更多
Posterior lumbopelvic fixation with iliac screws is the most commonly used method for unstable spinopelvic injuries. It has certain limitations including inability to use distraction along the spinopelvic rod as an in...Posterior lumbopelvic fixation with iliac screws is the most commonly used method for unstable spinopelvic injuries. It has certain limitations including inability to use distraction along the spinopelvic rod as an indirect reduction maneuver, need for complex 3-dimensional rod contouring and complications such as hardware prominence and soft tissue coverage. In the present case report,we described a surgical technique of lumbopelvic fixation with sacral alar screws for traumatic spinopelvic instability resulted from a unilateral Denis-Ⅲ comminuted sacral fracture and the L5 burst fracture. On the opposite side of the sacral fracture, caudal screws were implanted into the pedicle of the S1, whereas on the side of sacral fracture, two sacral alar screws were placed parallel to the superior sacral endplate as well as the plane of sacroiliac joint. In addition,horizontal stabilization was conducted with cross-link connections to maintain the longitudinal traction. For sacral fracture associated with traumatic spinopelvic instability,this modified lumbopelvic fixation technique using sacral alar screws makes longitudinal reduction easier, requires less rod contouring, and reduces hardware prominence without compromising the stability.展开更多
文摘针对虚拟机(virtual machine,VM)在不同子网间进行在线迁移时,因网络接入点发生改变而无法继续通信的问题,设计和实现了基于代理移动IP(proxy mobile IP,PMIP)的网络连接重定向系统。当VM迁移到外部子网时,将其看做移动节点,不改变IP地址,通过外部网络和家乡网络之间的双向隧道传输所有来自和发往该VM的网络数据。此方案中跨子网的在线迁移行为对VM以及与VM通信的节点透明。实验证明了该系统可以保证VM较快的网络切换速度和较好的网络通信性能。
基金Project F010206 supported by the National Natural Science Foundation of China
文摘In order to overcome the disadvantages of diagonal connection structures that are complex and for which it is difficult to derive the discriminant of the airflow directions of airways, we have applied a multiple regression method to analyze the effect, of changing the rules of mine airflows, on the stability of a mine ventilation system. The amount of air （ Qj ） is determined for the major airway and an optimum regression equation was derived for Qi as a function of the independent variable （ Ri ）, i.e., the venti- lation resistance between different airways. Therefore, corresponding countermeasures are proposed according to the changes in airflows. The calculated results agree very well with our practical situation, indicating that multiple regression analysis is simple, quick and practical and is therefore an effective method to analyze the stability of mine ventilation systems.
文摘Posterior lumbopelvic fixation with iliac screws is the most commonly used method for unstable spinopelvic injuries. It has certain limitations including inability to use distraction along the spinopelvic rod as an indirect reduction maneuver, need for complex 3-dimensional rod contouring and complications such as hardware prominence and soft tissue coverage. In the present case report,we described a surgical technique of lumbopelvic fixation with sacral alar screws for traumatic spinopelvic instability resulted from a unilateral Denis-Ⅲ comminuted sacral fracture and the L5 burst fracture. On the opposite side of the sacral fracture, caudal screws were implanted into the pedicle of the S1, whereas on the side of sacral fracture, two sacral alar screws were placed parallel to the superior sacral endplate as well as the plane of sacroiliac joint. In addition,horizontal stabilization was conducted with cross-link connections to maintain the longitudinal traction. For sacral fracture associated with traumatic spinopelvic instability,this modified lumbopelvic fixation technique using sacral alar screws makes longitudinal reduction easier, requires less rod contouring, and reduces hardware prominence without compromising the stability.
