The advent of drones is leading to a paradigm shift in courier services,while their large-scale deployment is confined by a limited range.Here,we design a low-cost product that allows drones to drop parcels onto and p...The advent of drones is leading to a paradigm shift in courier services,while their large-scale deployment is confined by a limited range.Here,we design a low-cost product that allows drones to drop parcels onto and pick them up from the roofs of moving passenger vehicles.With this,we propose a ground-air cooperation(GAC)based business model for parcel delivery in an urban environment.As per our case study using real-world data in Beijing,the new business model will not only shorten the parcel delivery time by 86.5% with a comparable cost,but also reduce road traffic by 8.6%,leading to an annual social benefit of 6.67 billion USD for Beijing.The proposed model utilizes the currently“wasted or unused”rooftops of passenger vehicles and has the potential to replace most parcel trucks and trailers,thus fundamentally addressing the congestion,noise,pollution,and road wear and tear problems caused by trucks,and bringing in immense social benefit.展开更多
为实现前沿阵地和地面防空两种典型应用约束条件下到达时间差(Time Difference of Arrival,TDOA)定位的自动布站优化,分析了这两种典型约束条件下的基站长度、站点间角度等对定位精度的影响。提出了基于自适应差分进化(Differential Evo...为实现前沿阵地和地面防空两种典型应用约束条件下到达时间差(Time Difference of Arrival,TDOA)定位的自动布站优化,分析了这两种典型约束条件下的基站长度、站点间角度等对定位精度的影响。提出了基于自适应差分进化(Differential Evolution,DE)算法的TDOA自动布站优化策略。采用该算法对这两种约束条件下的自动布站优化进行了仿真分析,并对自适应DE算法计算复杂度进行了分析。结果表明,自适应DE算法的自动布站复杂度低,收敛快速,与定位误差分析一致,具有较好的全局寻优能力。展开更多
文摘The advent of drones is leading to a paradigm shift in courier services,while their large-scale deployment is confined by a limited range.Here,we design a low-cost product that allows drones to drop parcels onto and pick them up from the roofs of moving passenger vehicles.With this,we propose a ground-air cooperation(GAC)based business model for parcel delivery in an urban environment.As per our case study using real-world data in Beijing,the new business model will not only shorten the parcel delivery time by 86.5% with a comparable cost,but also reduce road traffic by 8.6%,leading to an annual social benefit of 6.67 billion USD for Beijing.The proposed model utilizes the currently“wasted or unused”rooftops of passenger vehicles and has the potential to replace most parcel trucks and trailers,thus fundamentally addressing the congestion,noise,pollution,and road wear and tear problems caused by trucks,and bringing in immense social benefit.
文摘为实现前沿阵地和地面防空两种典型应用约束条件下到达时间差(Time Difference of Arrival,TDOA)定位的自动布站优化,分析了这两种典型约束条件下的基站长度、站点间角度等对定位精度的影响。提出了基于自适应差分进化(Differential Evolution,DE)算法的TDOA自动布站优化策略。采用该算法对这两种约束条件下的自动布站优化进行了仿真分析,并对自适应DE算法计算复杂度进行了分析。结果表明,自适应DE算法的自动布站复杂度低,收敛快速,与定位误差分析一致,具有较好的全局寻优能力。
