The upper bound of the optimal number of clusters in clustering algorithm is studied in this paper. A new method is proposed to solve this issue. This method shows that the rule cmax≤N^(1/N), which is popular in curr...The upper bound of the optimal number of clusters in clustering algorithm is studied in this paper. A new method is proposed to solve this issue. This method shows that the rule cmax≤N^(1/N), which is popular in current papers, is reasonable in some sense. The above conclusion is tested and analyzed by some typical examples in the literature, which demonstrates the validity of the new method.展开更多
Refined 3D modeling of mine slopes is pivotal for precise prediction of geological hazards.Aiming at the inadequacy of existing single modeling methods in comprehensively representing the overall and localized charact...Refined 3D modeling of mine slopes is pivotal for precise prediction of geological hazards.Aiming at the inadequacy of existing single modeling methods in comprehensively representing the overall and localized characteristics of mining slopes,this study introduces a new method that fuses model data from Unmanned aerial vehicles(UAV)tilt photogrammetry and 3D laser scanning through a data alignment algorithm based on control points.First,the mini batch K-Medoids algorithm is utilized to cluster the point cloud data from ground 3D laser scanning.Then,the elbow rule is applied to determine the optimal cluster number(K0),and the feature points are extracted.Next,the nearest neighbor point algorithm is employed to match the feature points obtained from UAV tilt photogrammetry,and the internal point coordinates are adjusted through the distanceweighted average to construct a 3D model.Finally,by integrating an engineering case study,the K0 value is determined to be 8,with a matching accuracy between the two model datasets ranging from 0.0669 to 1.0373 mm.Therefore,compared with the modeling method utilizing K-medoids clustering algorithm,the new modeling method significantly enhances the computational efficiency,the accuracy of selecting the optimal number of feature points in 3D laser scanning,and the precision of the 3D model derived from UAV tilt photogrammetry.This method provides a research foundation for constructing mine slope model.展开更多
为解决环形无线传感器网络能量空洞和能量最小问题,提出一种基于模糊控制的分簇路由算法FCRA(Fuzzy logic control based Clustering Routing Algorithm)。首先将网络分为宽度相等的环,以每环能耗最小为目标函数,计算出各环的最优簇数...为解决环形无线传感器网络能量空洞和能量最小问题,提出一种基于模糊控制的分簇路由算法FCRA(Fuzzy logic control based Clustering Routing Algorithm)。首先将网络分为宽度相等的环,以每环能耗最小为目标函数,计算出各环的最优簇数。然后设计簇头选举模糊控制器,其输入为节点剩余能量和到基站距离,输出为节点成为簇头概率。最后,采用簇间多跳模式进行数据传输,基于节点剩余能量、下一跳距离以及到基站跳数确定每条传输路径的权重函数,获得最优下一跳中继节点。仿真结果表明FCRA能有效减小网络能耗、延长网络生命周期。展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 69872003 and 40035010)
文摘The upper bound of the optimal number of clusters in clustering algorithm is studied in this paper. A new method is proposed to solve this issue. This method shows that the rule cmax≤N^(1/N), which is popular in current papers, is reasonable in some sense. The above conclusion is tested and analyzed by some typical examples in the literature, which demonstrates the validity of the new method.
基金funded by National Natural Science Foundation of China(Grant Nos.42272333,42277147).
文摘Refined 3D modeling of mine slopes is pivotal for precise prediction of geological hazards.Aiming at the inadequacy of existing single modeling methods in comprehensively representing the overall and localized characteristics of mining slopes,this study introduces a new method that fuses model data from Unmanned aerial vehicles(UAV)tilt photogrammetry and 3D laser scanning through a data alignment algorithm based on control points.First,the mini batch K-Medoids algorithm is utilized to cluster the point cloud data from ground 3D laser scanning.Then,the elbow rule is applied to determine the optimal cluster number(K0),and the feature points are extracted.Next,the nearest neighbor point algorithm is employed to match the feature points obtained from UAV tilt photogrammetry,and the internal point coordinates are adjusted through the distanceweighted average to construct a 3D model.Finally,by integrating an engineering case study,the K0 value is determined to be 8,with a matching accuracy between the two model datasets ranging from 0.0669 to 1.0373 mm.Therefore,compared with the modeling method utilizing K-medoids clustering algorithm,the new modeling method significantly enhances the computational efficiency,the accuracy of selecting the optimal number of feature points in 3D laser scanning,and the precision of the 3D model derived from UAV tilt photogrammetry.This method provides a research foundation for constructing mine slope model.
文摘为解决环形无线传感器网络能量空洞和能量最小问题,提出一种基于模糊控制的分簇路由算法FCRA(Fuzzy logic control based Clustering Routing Algorithm)。首先将网络分为宽度相等的环,以每环能耗最小为目标函数,计算出各环的最优簇数。然后设计簇头选举模糊控制器,其输入为节点剩余能量和到基站距离,输出为节点成为簇头概率。最后,采用簇间多跳模式进行数据传输,基于节点剩余能量、下一跳距离以及到基站跳数确定每条传输路径的权重函数,获得最优下一跳中继节点。仿真结果表明FCRA能有效减小网络能耗、延长网络生命周期。
