During range-based self-localization of Wireless Sensor Network (WSN) nodes, the number and placement methods of beacon nodes have a great influence on the accuracy of localization. This paper proves a theorem which d...During range-based self-localization of Wireless Sensor Network (WSN) nodes, the number and placement methods of beacon nodes have a great influence on the accuracy of localization. This paper proves a theorem which describes the relationship between the placement of beacon nodes and whether the node can be located in 3D indoor environment. In fact, as the highest locating accuracy can be acquired when the beacon nodes form one or more equilateral triangles in 2D plane, we generalizes this conclusion to 3D space, and proposes a beacon nodes selection algorithm based on the minimum condition number to get the higher locating accuracy, which can minimize the influence of distance measurement error. Simulation results show that the algorithm is effective and feasible.展开更多
The simulation of injection molding process requires a stable algorithm to model the molten polymer with non-isothermal non-Newtonian property.In this paper,a staggered and iterative scheme is particularly designed to...The simulation of injection molding process requires a stable algorithm to model the molten polymer with non-isothermal non-Newtonian property.In this paper,a staggered and iterative scheme is particularly designed to solve the velocity-pressure-temperature variables.In consideration of the polymer characteristic of high viscosity and low thermal conductivity,the non-Newtonian momentum-mass conservation equations are solved by the Crank-Nicolson method based split (CNBS) scheme,and the energy conservation equation with convective character is discretized by the characteristic Galerkin (CG) method.In addition,an arbitrary Lagrangian Eulerian (ALE) free surface tracking and mesh generation method is introduced to catch the front of the fluid flow.The efficiency of the proposed scheme is demonstrated by numerical experiments including a lid-driven cavity flow problem and an injection molding problem.展开更多
基金Supported by the National Natural Science Foundation of China (No.61003236 61171053)+2 种基金the Doctoral Fund of Ministry of Education of China (No.20113223110002)the Natural Science Major Program for Colleges and Universities in Jiangsu Province (No.11KJA520001)Science & Technology Innovation Fund for higher education institutions of Jiangsu Province (CXZZ12_0481)
文摘During range-based self-localization of Wireless Sensor Network (WSN) nodes, the number and placement methods of beacon nodes have a great influence on the accuracy of localization. This paper proves a theorem which describes the relationship between the placement of beacon nodes and whether the node can be located in 3D indoor environment. In fact, as the highest locating accuracy can be acquired when the beacon nodes form one or more equilateral triangles in 2D plane, we generalizes this conclusion to 3D space, and proposes a beacon nodes selection algorithm based on the minimum condition number to get the higher locating accuracy, which can minimize the influence of distance measurement error. Simulation results show that the algorithm is effective and feasible.
基金the National Natural Science Foundation of China(No. 50873060)the YuYao Technology Division Grand Science and Technology Special Project
文摘The simulation of injection molding process requires a stable algorithm to model the molten polymer with non-isothermal non-Newtonian property.In this paper,a staggered and iterative scheme is particularly designed to solve the velocity-pressure-temperature variables.In consideration of the polymer characteristic of high viscosity and low thermal conductivity,the non-Newtonian momentum-mass conservation equations are solved by the Crank-Nicolson method based split (CNBS) scheme,and the energy conservation equation with convective character is discretized by the characteristic Galerkin (CG) method.In addition,an arbitrary Lagrangian Eulerian (ALE) free surface tracking and mesh generation method is introduced to catch the front of the fluid flow.The efficiency of the proposed scheme is demonstrated by numerical experiments including a lid-driven cavity flow problem and an injection molding problem.
