Properties of continuous solutions of a second order polynomial-like iterated functional equation are given by considering its characteristic.A useful method to discuss the general case is described indeed in this pro...Properties of continuous solutions of a second order polynomial-like iterated functional equation are given by considering its characteristic.A useful method to discuss the general case is described indeed in this procedure.展开更多
With the rapid increase of Unmanned Aircraft Vehicle(UAV) numbers,the contradiction between extensive flight demands and limited low-altitude airspace resources has become increasingly prominent.To ensure the safety a...With the rapid increase of Unmanned Aircraft Vehicle(UAV) numbers,the contradiction between extensive flight demands and limited low-altitude airspace resources has become increasingly prominent.To ensure the safety and efficiency of low-altitude UAV operations,the low-altitude UAV public air route creatively proposed by the Chinese Academy of Sciences(CAS) and supported by the Civil Aviation Administration of China(CAAC) has been gradually recognized.However,present planning research on UAV low-altitude air route is not enough to explore how to use the ground transportation infrastructure,how to closely combine the surface pattern characteristics,and how to form the mechanism of "network".Based on the solution proposed in the early stage and related researches,this paper further deepens the exploration of the low-altitude public air route network and the implementation of key technologies and steps with an actual case study in Tianjin,China.Firstly,a path-planning environment consisting of favorable spaces,obstacle spaces,and mobile communication spaces for UAV flights was pre-constructed.Subsequently,air routes were planned by using the conflict detection and path re-planning algorithm.Our study also assessed the network by computing the population exposure risk index(PERI) and found that the index value was greatly reduced after the construction of the network,indicating that the network can effectively reduce the operational risk.In this study,a low-altitude UAV air route network in an actual region was constructed using multidisciplinary approaches such as remote sensing,geographic information,aviation,and transportation;it indirectly verified the rationality of the outcomes.This can provide practical solutions to low-altitude traffic problems in urban areas.展开更多
设X为一致光滑Banach空间,A:D（A） X→X为K-正定算子满足D（A）=D（K）,则存在常数β>0使得 x∈D（A）,||Ax||≤β||Kx||而且 f∈X,方程∧x=f有唯一解;设{an}n≥0为[0,1]中的实数列满足（i）an→0（n→∞）,（ii）sum from n=0...设X为一致光滑Banach空间,A:D（A） X→X为K-正定算子满足D（A）=D（K）,则存在常数β>0使得 x∈D（A）,||Ax||≤β||Kx||而且 f∈X,方程∧x=f有唯一解;设{an}n≥0为[0,1]中的实数列满足（i）an→0（n→∞）,（ii）sum from n=0 to ∞ an=∞, x0∈D（A）,迭代地定义序列{xn}n≥0如下:则{xn}n≥0强收敛于方程Ax=f的唯一解.展开更多
基金Supported by NSF of China,Sichuan Provincial Youth Sci-Tech Foundation and Math.Grant of CAS
文摘Properties of continuous solutions of a second order polynomial-like iterated functional equation are given by considering its characteristic.A useful method to discuss the general case is described indeed in this procedure.
基金National Key Research and Development Program of China,No.2017YFB0503005Key Research Program of the Chinese Academy of Sciences,No.ZDRW-KT-2020-2+1 种基金National Natural Science Foundation of China,No.41971359,No.41771388Tianjin Intelligent Manufacturing Project Technology of Intelligent Networking by Autonomous Control UAVs for Observation and Application,No.Tianjin-IMP-2。
文摘With the rapid increase of Unmanned Aircraft Vehicle(UAV) numbers,the contradiction between extensive flight demands and limited low-altitude airspace resources has become increasingly prominent.To ensure the safety and efficiency of low-altitude UAV operations,the low-altitude UAV public air route creatively proposed by the Chinese Academy of Sciences(CAS) and supported by the Civil Aviation Administration of China(CAAC) has been gradually recognized.However,present planning research on UAV low-altitude air route is not enough to explore how to use the ground transportation infrastructure,how to closely combine the surface pattern characteristics,and how to form the mechanism of "network".Based on the solution proposed in the early stage and related researches,this paper further deepens the exploration of the low-altitude public air route network and the implementation of key technologies and steps with an actual case study in Tianjin,China.Firstly,a path-planning environment consisting of favorable spaces,obstacle spaces,and mobile communication spaces for UAV flights was pre-constructed.Subsequently,air routes were planned by using the conflict detection and path re-planning algorithm.Our study also assessed the network by computing the population exposure risk index(PERI) and found that the index value was greatly reduced after the construction of the network,indicating that the network can effectively reduce the operational risk.In this study,a low-altitude UAV air route network in an actual region was constructed using multidisciplinary approaches such as remote sensing,geographic information,aviation,and transportation;it indirectly verified the rationality of the outcomes.This can provide practical solutions to low-altitude traffic problems in urban areas.
文摘设X为一致光滑Banach空间,A:D（A） X→X为K-正定算子满足D（A）=D（K）,则存在常数β>0使得 x∈D（A）,||Ax||≤β||Kx||而且 f∈X,方程∧x=f有唯一解;设{an}n≥0为[0,1]中的实数列满足（i）an→0（n→∞）,（ii）sum from n=0 to ∞ an=∞, x0∈D（A）,迭代地定义序列{xn}n≥0如下:则{xn}n≥0强收敛于方程Ax=f的唯一解.
