In the conventional differential quadrature (DQ) method the functional values along a mesh line are used to approximate derivatives and its application is limited to regular regions. In this paper, a local different...In the conventional differential quadrature (DQ) method the functional values along a mesh line are used to approximate derivatives and its application is limited to regular regions. In this paper, a local differential quadrature (LDQ) method was developed by using irregular distributed nodes, where any spatial derivative at a nodal point is approximated by a linear weighted sum of the functional values of nodes in the local physical domain. The weighting coefficients in the new approach are determined by the quadrature rule with the aid of nodal interpolation. Since the proposed method directly approximates the derivative, it can be consistently well applied to linear and nonlinear problems and the mesh-free feature is still kept. Numerical examples are provided to validate the LDQ method.展开更多
为提高物联网(IOT)应用中源节点位置距离基站较近时的隐私保护强度,提出基于不规则环的源位置隐私保护路由协议RBIR(routing based irregular ring)。设计一种创建不规则环的方法并分析环的最佳创建区域,结合中间节点实现数据包的转发...为提高物联网(IOT)应用中源节点位置距离基站较近时的隐私保护强度,提出基于不规则环的源位置隐私保护路由协议RBIR(routing based irregular ring)。设计一种创建不规则环的方法并分析环的最佳创建区域,结合中间节点实现数据包的转发。中间节点的选择受到约束,避免路径交叉;动态更新环节点,使环节点能耗分散,延长网络寿命。仿真结果表明,RBIR的网络寿命较长且安全性较好,当源节点距离基站较近时,有效保证了源位置的隐私。展开更多
为了改善四边形网格的拓扑连接关系,针对Liu等提出的优化方法[1](Liu Jianfei,Sun Shuli,Chen Yongqiang.A new method of quality improvement for quadrilateral mesh based on small polygon reconnection).Acta Mechanica Sinica,20...为了改善四边形网格的拓扑连接关系,针对Liu等提出的优化方法[1](Liu Jianfei,Sun Shuli,Chen Yongqiang.A new method of quality improvement for quadrilateral mesh based on small polygon reconnection).Acta Mechanica Sinica,2012,28(1):140-145),提出了面向不规则点消除的四边形网格优化方法.首先引入了一个加速策略,使每次操作可以处理的区域更大,从而提高了消除不规则点的能力;其次将方法拓展至曲面网格的优化.数值实验结果表明,该方法既能够大幅度改善ANSYS等数值模拟软件生成的四边形网格,也能进一步提高使用图形学领域方法得出的四边形网格的质量.展开更多
文摘In the conventional differential quadrature (DQ) method the functional values along a mesh line are used to approximate derivatives and its application is limited to regular regions. In this paper, a local differential quadrature (LDQ) method was developed by using irregular distributed nodes, where any spatial derivative at a nodal point is approximated by a linear weighted sum of the functional values of nodes in the local physical domain. The weighting coefficients in the new approach are determined by the quadrature rule with the aid of nodal interpolation. Since the proposed method directly approximates the derivative, it can be consistently well applied to linear and nonlinear problems and the mesh-free feature is still kept. Numerical examples are provided to validate the LDQ method.
文摘为提高物联网(IOT)应用中源节点位置距离基站较近时的隐私保护强度,提出基于不规则环的源位置隐私保护路由协议RBIR(routing based irregular ring)。设计一种创建不规则环的方法并分析环的最佳创建区域,结合中间节点实现数据包的转发。中间节点的选择受到约束,避免路径交叉;动态更新环节点,使环节点能耗分散,延长网络寿命。仿真结果表明,RBIR的网络寿命较长且安全性较好,当源节点距离基站较近时,有效保证了源位置的隐私。
文摘为了改善四边形网格的拓扑连接关系,针对Liu等提出的优化方法[1](Liu Jianfei,Sun Shuli,Chen Yongqiang.A new method of quality improvement for quadrilateral mesh based on small polygon reconnection).Acta Mechanica Sinica,2012,28(1):140-145),提出了面向不规则点消除的四边形网格优化方法.首先引入了一个加速策略,使每次操作可以处理的区域更大,从而提高了消除不规则点的能力;其次将方法拓展至曲面网格的优化.数值实验结果表明,该方法既能够大幅度改善ANSYS等数值模拟软件生成的四边形网格,也能进一步提高使用图形学领域方法得出的四边形网格的质量.