Wireless Mesh Network （WMN） is seen as an effective Intemet access solution for dynamic wireless applications. For the low mobility of mesh routers in WMN, the backbone topography can be effectively maintained by pr...Wireless Mesh Network （WMN） is seen as an effective Intemet access solution for dynamic wireless applications. For the low mobility of mesh routers in WMN, the backbone topography can be effectively maintained by proactive routing protocol. Pre-proposals like Tree Based Routing （TBR） protocol and Root Driven Routing （RDR） protocol are so centralized that they make the gateway becorre a bottleneck which severely restricts the network performance. We proposed an Optimized Tree-based Routing （OTR） protocol that logically separated the proactive tree into pieces. Route is partly computed by the branches instead of root. We also discussed the operation of multipie Intemet gateways which is a main issue in WMN. The new proposal lightens the load in root, reduces the overhead and improves the throughput. Numerical analysis and simulation results confirm that the perforrmnce of WMN is improved and OTR is more suitable for large scale WMN.展开更多
In this paper,the soil-pile system of O-cell test of pile is simplified as an axi-symmetric problem.By using aggregation of quadrilateral isoparametric elements to simulate pile and soil,setting Goodman's elements...In this paper,the soil-pile system of O-cell test of pile is simplified as an axi-symmetric problem.By using aggregation of quadrilateral isoparametric elements to simulate pile and soil,setting Goodman's elements between pile and soils,a method of numerical simulation analysis on O-cell test of pile is presented with the consideration of nonlinear mechanical behavior of soils and pile-soil interface.The method is applied to the analysis of a case of O-cell test of pile.The load-displacement curves and axial force curves of upper pile and lower pile obtained from the O-cell test of pile are fitted,and parameters of the mechanical model of soils and interface are determined.Analysis results validate that the numerical simulation analysis method put forward in this paper is applicable.Furthermore,the interaction and influence of upper pile and lower pile in the O-cell test are also studied with the method.The result shows that if load box is located in a soil layer with fine mechanical behavior,the interaction of upper pile and lower pile in O-cell test can be ignored generally.展开更多
基金Acknowledgements This paper was supported by the Major National Science and Technology program under Grant No. 2011ZX03005-002 the National Natural Science Foundation of China under Grant No. 61100233 the Fundamental Universities under Grant No Research Funds for the Central K50510030010.
文摘Wireless Mesh Network （WMN） is seen as an effective Intemet access solution for dynamic wireless applications. For the low mobility of mesh routers in WMN, the backbone topography can be effectively maintained by proactive routing protocol. Pre-proposals like Tree Based Routing （TBR） protocol and Root Driven Routing （RDR） protocol are so centralized that they make the gateway becorre a bottleneck which severely restricts the network performance. We proposed an Optimized Tree-based Routing （OTR） protocol that logically separated the proactive tree into pieces. Route is partly computed by the branches instead of root. We also discussed the operation of multipie Intemet gateways which is a main issue in WMN. The new proposal lightens the load in root, reduces the overhead and improves the throughput. Numerical analysis and simulation results confirm that the perforrmnce of WMN is improved and OTR is more suitable for large scale WMN.
文摘In this paper,the soil-pile system of O-cell test of pile is simplified as an axi-symmetric problem.By using aggregation of quadrilateral isoparametric elements to simulate pile and soil,setting Goodman's elements between pile and soils,a method of numerical simulation analysis on O-cell test of pile is presented with the consideration of nonlinear mechanical behavior of soils and pile-soil interface.The method is applied to the analysis of a case of O-cell test of pile.The load-displacement curves and axial force curves of upper pile and lower pile obtained from the O-cell test of pile are fitted,and parameters of the mechanical model of soils and interface are determined.Analysis results validate that the numerical simulation analysis method put forward in this paper is applicable.Furthermore,the interaction and influence of upper pile and lower pile in the O-cell test are also studied with the method.The result shows that if load box is located in a soil layer with fine mechanical behavior,the interaction of upper pile and lower pile in O-cell test can be ignored generally.
