The increasing emergence of the time-series single-cell RNA sequencing(scRNA-seq)data,inferring developmental trajectory by connecting transcriptome similar cell states(i.e.,cell types or clusters)has become a major c...The increasing emergence of the time-series single-cell RNA sequencing(scRNA-seq)data,inferring developmental trajectory by connecting transcriptome similar cell states(i.e.,cell types or clusters)has become a major challenge.Most existing computational methods are designed for individual cells and do not take into account the available time series information.We present IDTI based on the Increment of Diversity for Trajectory Inference,which combines time series information and the minimum increment of diversity method to infer cell state trajectory of time-series scRNA-seq data.We apply IDTI to simulated and three real diverse tissue development datasets,and compare it with six other commonly used trajectory inference methods in terms of topology similarity and branching accuracy.The results have shown that the IDTI method accurately constructs the cell state trajectory without the requirement of starting cells.In the performance test,we further demonstrate that IDTI has the advantages of high accuracy and strong robustness.展开更多
With the rapid development of data-driven intelligent transportation systems,an efficient route recommendation method for taxis has become a hot topic in smart cities.We present an effective taxi route recommendation ...With the rapid development of data-driven intelligent transportation systems,an efficient route recommendation method for taxis has become a hot topic in smart cities.We present an effective taxi route recommendation approach(called APFD)based on the artificial potential field(APF)method and Dijkstra method with mobile trajectory big data.Specifically,to improve the efficiency of route recommendation,we propose a region extraction method that searches for a region including the optimal route through the origin and destination coordinates.Then,based on the APF method,we put forward an effective approach for removing redundant nodes.Finally,we employ the Dijkstra method to determine the optimal route recommendation.In particular,the APFD approach is applied to a simulation map and the real-world road network on the Fourth Ring Road in Beijing.On the map,we randomly select 20 pairs of origin and destination coordinates and use APFD with the ant colony(AC)algorithm,greedy algorithm(A*),APF,rapid-exploration random tree(RRT),non-dominated sorting genetic algorithm-II(NSGA-II),particle swarm optimization(PSO),and Dijkstra for the shortest route recommendation.Compared with AC,A*,APF,RRT,NSGA-II,and PSO,concerning shortest route planning,APFD improves route planning capability by 1.45%–39.56%,4.64%–54.75%,8.59%–37.25%,5.06%–45.34%,0.94%–20.40%,and 2.43%–38.31%,respectively.Compared with Dijkstra,the performance of APFD is improved by 1.03–27.75 times in terms of the execution efficiency.In addition,in the real-world road network,on the Fourth Ring Road in Beijing,the ability of APFD to recommend the shortest route is better than those of AC,A*,APF,RRT,NSGA-II,and PSO,and the execution efficiency of APFD is higher than that of the Dijkstra method.展开更多
以深圳市出租车GPS数据为基础,运用时空拓展的轨迹数据场聚类方法提取城市交通热点区域,结合城市POI(Point of Interest)数据和地理实况对热点区域加以理解和分析。基于复杂网络的视角,计算交互分析指标并可视化热点区域的空间交互网络...以深圳市出租车GPS数据为基础,运用时空拓展的轨迹数据场聚类方法提取城市交通热点区域,结合城市POI(Point of Interest)数据和地理实况对热点区域加以理解和分析。基于复杂网络的视角,计算交互分析指标并可视化热点区域的空间交互网络,探究城市交通和居民出行的时空规律。结果表明:1)交通枢纽(机场、火车站和口岸)、综合性商圈、城市重要主干道周边和城市商务中心在节假日和工作日均表现为持续热点区域;2)节假日热点区域分布较"发散",主要反映了居民个性化出行需求;3)工作日热点区域分布较"收敛",主要表现为职住分离的通勤模式;4)不同热点区域在空间交互网络中的重要性存在明显差异,其空间交互体现了距离衰减效应和局部抱团现象,居民出行的热点区域网络本身具有小世界效应和无标度特征。展开更多
基金the National Natural Science Foundation of China(62061034,62171241)the key technology research program of Inner Mongolia Autonomous Region(2021GG0398)the Science and Technology Leading Talent Team in Inner Mongolia Autonomous Region(2022LJRC0009).
文摘The increasing emergence of the time-series single-cell RNA sequencing(scRNA-seq)data,inferring developmental trajectory by connecting transcriptome similar cell states(i.e.,cell types or clusters)has become a major challenge.Most existing computational methods are designed for individual cells and do not take into account the available time series information.We present IDTI based on the Increment of Diversity for Trajectory Inference,which combines time series information and the minimum increment of diversity method to infer cell state trajectory of time-series scRNA-seq data.We apply IDTI to simulated and three real diverse tissue development datasets,and compare it with six other commonly used trajectory inference methods in terms of topology similarity and branching accuracy.The results have shown that the IDTI method accurately constructs the cell state trajectory without the requirement of starting cells.In the performance test,we further demonstrate that IDTI has the advantages of high accuracy and strong robustness.
基金the National Natural Science Foundation of China(Nos.62162012,62173278,and 62072061)the Science and Technology Support Program of Guizhou Province,China(No.QKHZC2021YB531)+3 种基金the Youth Science and Technology Talents Development Project of Colleges and Universities in Guizhou Province,China(No.QJHKY2022175)the Science and Technology Foundation of Guizhou Province,China(Nos.QKHJCZK2022YB195 and QKHJCZK2022YB197)the Natural Science Research Project of the Department of Education of Guizhou Province,China(No.QJJ2022015)the Scientific Research Platform Project of Guizhou Minzu University,China(No.GZMUSYS[2021]04)。
文摘With the rapid development of data-driven intelligent transportation systems,an efficient route recommendation method for taxis has become a hot topic in smart cities.We present an effective taxi route recommendation approach(called APFD)based on the artificial potential field(APF)method and Dijkstra method with mobile trajectory big data.Specifically,to improve the efficiency of route recommendation,we propose a region extraction method that searches for a region including the optimal route through the origin and destination coordinates.Then,based on the APF method,we put forward an effective approach for removing redundant nodes.Finally,we employ the Dijkstra method to determine the optimal route recommendation.In particular,the APFD approach is applied to a simulation map and the real-world road network on the Fourth Ring Road in Beijing.On the map,we randomly select 20 pairs of origin and destination coordinates and use APFD with the ant colony(AC)algorithm,greedy algorithm(A*),APF,rapid-exploration random tree(RRT),non-dominated sorting genetic algorithm-II(NSGA-II),particle swarm optimization(PSO),and Dijkstra for the shortest route recommendation.Compared with AC,A*,APF,RRT,NSGA-II,and PSO,concerning shortest route planning,APFD improves route planning capability by 1.45%–39.56%,4.64%–54.75%,8.59%–37.25%,5.06%–45.34%,0.94%–20.40%,and 2.43%–38.31%,respectively.Compared with Dijkstra,the performance of APFD is improved by 1.03–27.75 times in terms of the execution efficiency.In addition,in the real-world road network,on the Fourth Ring Road in Beijing,the ability of APFD to recommend the shortest route is better than those of AC,A*,APF,RRT,NSGA-II,and PSO,and the execution efficiency of APFD is higher than that of the Dijkstra method.
文摘以深圳市出租车GPS数据为基础,运用时空拓展的轨迹数据场聚类方法提取城市交通热点区域,结合城市POI(Point of Interest)数据和地理实况对热点区域加以理解和分析。基于复杂网络的视角,计算交互分析指标并可视化热点区域的空间交互网络,探究城市交通和居民出行的时空规律。结果表明:1)交通枢纽(机场、火车站和口岸)、综合性商圈、城市重要主干道周边和城市商务中心在节假日和工作日均表现为持续热点区域;2)节假日热点区域分布较"发散",主要反映了居民个性化出行需求;3)工作日热点区域分布较"收敛",主要表现为职住分离的通勤模式;4)不同热点区域在空间交互网络中的重要性存在明显差异,其空间交互体现了距离衰减效应和局部抱团现象,居民出行的热点区域网络本身具有小世界效应和无标度特征。
