The practical engineering of satellite tracking telemetry and command(TT&C)is often disturbed by unpredictable external factors,including the temporary rise in a significant quantity of satellite TT&C tasks,te...The practical engineering of satellite tracking telemetry and command(TT&C)is often disturbed by unpredictable external factors,including the temporary rise in a significant quantity of satellite TT&C tasks,temporary failures and failures of some TT&C resources,and so on.To improve the adaptability and robustness of satellite TT&C systems when faced with uncertain dynamic disturbances,a hierarchical disturbance propagation mechanism and an improved contract network dynamic scheduling method for satellite TT&C resources were designed to address the dynamic scheduling problem of satellite TT&C resources.Firstly,the characteristics of the dynamic scheduling problem of satellite TT&C resources are analyzed,and a mathematical model is established with the weighted optimization objectives of maximizing the revenue from task completion and minimizing the degree of plan disturbance.Then,a bottom-up distributed dynamic collaborative scheduling framework for satellite TT&C resources is proposed,which includes a task layer,a resource layer,a central internal collaboration layer,and a central external collaboration layer.Dynamic disturbances are propagated layer by layer from the task layer to the central external collaboration layer in a bottom-up manner,using efficient heuristic strategies in the task layer and the resource layer,respectively.We use improved contract network algorithms in the center internal collaboration layer and the center external collaboration layer,the original scheduling plan is quickly adjusted to minimize the impact of disturbances while effectively completing dynamic task requirements.Finally,a large number of simulation experiments were carried out and compared with various comparative algorithms.The results show that the proposed algorithm can effectively improve the solution effect of satellite TT&C resource dynamic scheduling problems,and has good application prospects.展开更多
Rural urbanization driven by e-commerce is a new bottom-up urbanization process originating in the information era.The systematical restructuring that this process brings about in the social life,economic environment,...Rural urbanization driven by e-commerce is a new bottom-up urbanization process originating in the information era.The systematical restructuring that this process brings about in the social life,economic environment,and physical space of the countryside,which is reflected in characteristics such as the leaping non-agriculturalization of employment,the comprehensive modernization of rural life,and the intensive spatial urbanization.Obviously,there are many common features between this new process and the old one in the past three decades,but progresses also exist.The distinctions of the countryside,such as a low-cost entrepreneurial environment,local non-agricultural industry,and resources of specialty agricultural products,are manifested in the process.Combined with the Internet and e-commerce by the rural grassroots entrepreneurs,they enable rural area to break the location constrains and join in the national even global industry division,and further realize the leaping development of scale and function.Meanwhile,the capital and talents back to the rural areas are an important guarantee for the upgrading of rural development.Consequentially,the developing and planning idea of smart shrinking is necessary for the rural urbanization process driven by e-commerce in China.展开更多
基金This work was supported in part by the National Natural Science Foundation of China(No.62373380).
文摘The practical engineering of satellite tracking telemetry and command(TT&C)is often disturbed by unpredictable external factors,including the temporary rise in a significant quantity of satellite TT&C tasks,temporary failures and failures of some TT&C resources,and so on.To improve the adaptability and robustness of satellite TT&C systems when faced with uncertain dynamic disturbances,a hierarchical disturbance propagation mechanism and an improved contract network dynamic scheduling method for satellite TT&C resources were designed to address the dynamic scheduling problem of satellite TT&C resources.Firstly,the characteristics of the dynamic scheduling problem of satellite TT&C resources are analyzed,and a mathematical model is established with the weighted optimization objectives of maximizing the revenue from task completion and minimizing the degree of plan disturbance.Then,a bottom-up distributed dynamic collaborative scheduling framework for satellite TT&C resources is proposed,which includes a task layer,a resource layer,a central internal collaboration layer,and a central external collaboration layer.Dynamic disturbances are propagated layer by layer from the task layer to the central external collaboration layer in a bottom-up manner,using efficient heuristic strategies in the task layer and the resource layer,respectively.We use improved contract network algorithms in the center internal collaboration layer and the center external collaboration layer,the original scheduling plan is quickly adjusted to minimize the impact of disturbances while effectively completing dynamic task requirements.Finally,a large number of simulation experiments were carried out and compared with various comparative algorithms.The results show that the proposed algorithm can effectively improve the solution effect of satellite TT&C resource dynamic scheduling problems,and has good application prospects.
基金supported by the Natural Science Foundation of China,No.51478216
文摘Rural urbanization driven by e-commerce is a new bottom-up urbanization process originating in the information era.The systematical restructuring that this process brings about in the social life,economic environment,and physical space of the countryside,which is reflected in characteristics such as the leaping non-agriculturalization of employment,the comprehensive modernization of rural life,and the intensive spatial urbanization.Obviously,there are many common features between this new process and the old one in the past three decades,but progresses also exist.The distinctions of the countryside,such as a low-cost entrepreneurial environment,local non-agricultural industry,and resources of specialty agricultural products,are manifested in the process.Combined with the Internet and e-commerce by the rural grassroots entrepreneurs,they enable rural area to break the location constrains and join in the national even global industry division,and further realize the leaping development of scale and function.Meanwhile,the capital and talents back to the rural areas are an important guarantee for the upgrading of rural development.Consequentially,the developing and planning idea of smart shrinking is necessary for the rural urbanization process driven by e-commerce in China.
