The increasing demand for interactive mobile multimedia service is causing the integration of 3rd generation （3G） cellular systems and wireless broadcast systems. The key challenge is to support data dissemination w...The increasing demand for interactive mobile multimedia service is causing the integration of 3rd generation （3G） cellular systems and wireless broadcast systems. The key challenge is to support data dissemination with low response time, request drop rate, and the unfairness of request drop. This article proposes a novel scheduling algorithm called DAG （on-demand scheduling utilizing analytic hierarchy process （AHP） and grey relational analysis （GRA））, which takes multiple factors--waiting time, number of active requests, deadline--into consideration, and models the data scheduling process as a multiple factors＇ decision-making and best option-selecting process. The proposed approach comprises two parts. The first part applies AHP to decide the relative weights of multiple decision factors according to user requests, while the second adopts GRA to rank the data item alternatives through the similarity between each option and the ideal option. Simulation results are presented to demonstrate that DAG performs well in the multiple criterions mentioned above.展开更多
As urbanization and high-rise living increase,frequent delivery of goods in the building to higher floors from the ground level is becoming a pressing issue.We introduce a drone-based vertical delivery system aimed at...As urbanization and high-rise living increase,frequent delivery of goods in the building to higher floors from the ground level is becoming a pressing issue.We introduce a drone-based vertical delivery system aimed at enhancing the efficiency of high-rise building logistics.The potential of the proposed system in reducing delivery time and energy consumption compared to conventional elevator-based delivery is analyzed.By assessing the requisite number of drones,their operating frequencies,and identifying scenarios in which drones can surpass conventional methods,the advantages using drone delivery systems are highlighted.The results indicate that drone delivery is not only viable but also advantageous to meet certain demand levels,offering a promising alternative to elevator-based deliveries.展开更多
目的随着车联网技术的发展,网联自动驾驶车辆(connected and autonomous vehicle,CAV)的部署场景变得越来越复杂。为了保证效率和安全,提出一种面向CAV部署的集成无人机和现有路侧基础设施的车—路—无人机跨域协同技术,旨在解决依靠路...目的随着车联网技术的发展,网联自动驾驶车辆(connected and autonomous vehicle,CAV)的部署场景变得越来越复杂。为了保证效率和安全,提出一种面向CAV部署的集成无人机和现有路侧基础设施的车—路—无人机跨域协同技术,旨在解决依靠路侧基础设施支持CAV感知和通信解决方案在部署范围、机动性和感知视角等方面存在一定限制的问题。方法本文设计了基于任务需求和资源约束的双层调度算法,实现无人机资源的灵活调度和智能决策。该算法上层实现任务规划,下层运动规划则根据动力学约束和虚拟场模型生成无人机运动轨迹,采用上、下层反馈机制,动态响应感知和通信需求,给出目标区域无人机的最优部署方案。结果实验模拟混合交通流场景,并估计了不同场景下CAV动态感知和通信需求;通过对比无人机跨域协同方案与现有路侧基础设施辅助方案,结果表明所提方案相比现有方案降低了路侧设备单元(roadside units,RSU)的空闲率,在CAV渗透率为70%时,所提方案在仿真路网和城市路网场景下分别将RSU的空闲率降低了33.82%和31.20%;同时也展示了基于双层调度算法按需调度无人机的流程,验证了该算法的有效性。结论本文所提出的无人机跨域协同的CAV辅助部署方案,对比现有的基础设施辅助方案,具有覆盖范围广、可以按需灵活调度的特点,可以支持CAV大规模部署。展开更多
基金EU project under the information society technologies（IST）Programme（045461）； the National Natural Science Foundation of China（60772112）.
文摘The increasing demand for interactive mobile multimedia service is causing the integration of 3rd generation （3G） cellular systems and wireless broadcast systems. The key challenge is to support data dissemination with low response time, request drop rate, and the unfairness of request drop. This article proposes a novel scheduling algorithm called DAG （on-demand scheduling utilizing analytic hierarchy process （AHP） and grey relational analysis （GRA））, which takes multiple factors--waiting time, number of active requests, deadline--into consideration, and models the data scheduling process as a multiple factors＇ decision-making and best option-selecting process. The proposed approach comprises two parts. The first part applies AHP to decide the relative weights of multiple decision factors according to user requests, while the second adopts GRA to rank the data item alternatives through the similarity between each option and the ideal option. Simulation results are presented to demonstrate that DAG performs well in the multiple criterions mentioned above.
文摘As urbanization and high-rise living increase,frequent delivery of goods in the building to higher floors from the ground level is becoming a pressing issue.We introduce a drone-based vertical delivery system aimed at enhancing the efficiency of high-rise building logistics.The potential of the proposed system in reducing delivery time and energy consumption compared to conventional elevator-based delivery is analyzed.By assessing the requisite number of drones,their operating frequencies,and identifying scenarios in which drones can surpass conventional methods,the advantages using drone delivery systems are highlighted.The results indicate that drone delivery is not only viable but also advantageous to meet certain demand levels,offering a promising alternative to elevator-based deliveries.
文摘目的随着车联网技术的发展,网联自动驾驶车辆(connected and autonomous vehicle,CAV)的部署场景变得越来越复杂。为了保证效率和安全,提出一种面向CAV部署的集成无人机和现有路侧基础设施的车—路—无人机跨域协同技术,旨在解决依靠路侧基础设施支持CAV感知和通信解决方案在部署范围、机动性和感知视角等方面存在一定限制的问题。方法本文设计了基于任务需求和资源约束的双层调度算法,实现无人机资源的灵活调度和智能决策。该算法上层实现任务规划,下层运动规划则根据动力学约束和虚拟场模型生成无人机运动轨迹,采用上、下层反馈机制,动态响应感知和通信需求,给出目标区域无人机的最优部署方案。结果实验模拟混合交通流场景,并估计了不同场景下CAV动态感知和通信需求;通过对比无人机跨域协同方案与现有路侧基础设施辅助方案,结果表明所提方案相比现有方案降低了路侧设备单元(roadside units,RSU)的空闲率,在CAV渗透率为70%时,所提方案在仿真路网和城市路网场景下分别将RSU的空闲率降低了33.82%和31.20%;同时也展示了基于双层调度算法按需调度无人机的流程,验证了该算法的有效性。结论本文所提出的无人机跨域协同的CAV辅助部署方案,对比现有的基础设施辅助方案,具有覆盖范围广、可以按需灵活调度的特点,可以支持CAV大规模部署。
