针对移动传感器网络(Mobile sensor networks,MSNs)中动态目标(事件源)的监测优化问题,为提高网络覆盖质量,建立基于Voronoi剖分的监测性能(Quality of monitoring,QoM)评价函数,提出基于群集控制的传感器节点部署分布式控制算法.每个...针对移动传感器网络(Mobile sensor networks,MSNs)中动态目标(事件源)的监测优化问题,为提高网络覆盖质量,建立基于Voronoi剖分的监测性能(Quality of monitoring,QoM)评价函数,提出基于群集控制的传感器节点部署分布式控制算法.每个节点在本地结合最小二乘法和一致性算法来估计目标相对位置.相比传统算法,本文算法只需本地和单跳通信(可观测)邻居的信息,从而减小通信时长和能耗.算法在提高以目标为中心的一定区域监测性能的同时,使全体传感器速度趋于一致,从而在尽量保持网络拓扑结构的同时减少了整体移动能耗.在目标匀速或目标加速度信息全网可知的情况下,全体传感器速度渐近收敛至目标速度,且监测性能收敛至局部最优.所采用的目标位置估计滤波算法计算简单、切实可行.展开更多
Early water breakthrough and a rapid increase in water cut are always observed in high- permeability completion intervals when perforations are uniformly distributed in the wellbore in heterogeneous reservoirs. Optimi...Early water breakthrough and a rapid increase in water cut are always observed in high- permeability completion intervals when perforations are uniformly distributed in the wellbore in heterogeneous reservoirs. Optimization of perforating parameters in partitioned sections in horizontal intervals helps homogenize the inflow from the reservoir and thus is critically important for enhanced oil recovery. This paper derives a coupled reservoir-wellbore flow model based on inflow controlling theory. Genetic algorithms are applied to solving the model as they excel in obtaining the global optimum of discrete functions. The optimized perforating strategy applies a low perforation density in high- permeability intervals and a high perforation density in low-permeability intervals. As a result, the inflow profile is homogenized and idealized.展开更多
This paper presents an extended sequential element rejection and admission(SERA)topology optimizationmethod with a region partitioning strategy.Based on the partitioning of a design domain into solid regions and weak ...This paper presents an extended sequential element rejection and admission(SERA)topology optimizationmethod with a region partitioning strategy.Based on the partitioning of a design domain into solid regions and weak regions,the proposed optimizationmethod sequentially implements finite element analysis(FEA)in these regions.After standard FEA in the solid regions,the boundary displacement of the weak regions is constrained using the numerical solution of the solid regions as Dirichlet boundary conditions.This treatment can alleviate the negative effect of the material interpolation model of the topology optimization method in the weak regions,such as the condition number of the structural global stiffness matrix.For optimization,in which the forward problem requires nonlinear structural analysis,a linear solver can be applied in weak regions to avoid numerical singularities caused by the over-deformedmesh.To enhance the robustness of the proposedmethod,the nonmanifold point and island are identified and handled separately.The performance of the proposed method is verified by three 2D minimum compliance examples.展开更多
文摘针对移动传感器网络(Mobile sensor networks,MSNs)中动态目标(事件源)的监测优化问题,为提高网络覆盖质量,建立基于Voronoi剖分的监测性能(Quality of monitoring,QoM)评价函数,提出基于群集控制的传感器节点部署分布式控制算法.每个节点在本地结合最小二乘法和一致性算法来估计目标相对位置.相比传统算法,本文算法只需本地和单跳通信(可观测)邻居的信息,从而减小通信时长和能耗.算法在提高以目标为中心的一定区域监测性能的同时,使全体传感器速度趋于一致,从而在尽量保持网络拓扑结构的同时减少了整体移动能耗.在目标匀速或目标加速度信息全网可知的情况下,全体传感器速度渐近收敛至目标速度,且监测性能收敛至局部最优.所采用的目标位置估计滤波算法计算简单、切实可行.
基金supported by National Scientific Project(No. 2008ZX05024-03)
文摘Early water breakthrough and a rapid increase in water cut are always observed in high- permeability completion intervals when perforations are uniformly distributed in the wellbore in heterogeneous reservoirs. Optimization of perforating parameters in partitioned sections in horizontal intervals helps homogenize the inflow from the reservoir and thus is critically important for enhanced oil recovery. This paper derives a coupled reservoir-wellbore flow model based on inflow controlling theory. Genetic algorithms are applied to solving the model as they excel in obtaining the global optimum of discrete functions. The optimized perforating strategy applies a low perforation density in high- permeability intervals and a high perforation density in low-permeability intervals. As a result, the inflow profile is homogenized and idealized.
基金supported by the National Science Foundation of China (Grant No.51675506).
文摘This paper presents an extended sequential element rejection and admission(SERA)topology optimizationmethod with a region partitioning strategy.Based on the partitioning of a design domain into solid regions and weak regions,the proposed optimizationmethod sequentially implements finite element analysis(FEA)in these regions.After standard FEA in the solid regions,the boundary displacement of the weak regions is constrained using the numerical solution of the solid regions as Dirichlet boundary conditions.This treatment can alleviate the negative effect of the material interpolation model of the topology optimization method in the weak regions,such as the condition number of the structural global stiffness matrix.For optimization,in which the forward problem requires nonlinear structural analysis,a linear solver can be applied in weak regions to avoid numerical singularities caused by the over-deformedmesh.To enhance the robustness of the proposedmethod,the nonmanifold point and island are identified and handled separately.The performance of the proposed method is verified by three 2D minimum compliance examples.
