A simple fast method is given for sequentially retrieving all the records in a B tree. A file structure for database is proposed. The records in its primary data file are sorted according to the key order. A B tree ...A simple fast method is given for sequentially retrieving all the records in a B tree. A file structure for database is proposed. The records in its primary data file are sorted according to the key order. A B tree is used as its dense index. It is easy to insert, delete or search a record, and it is also convenient to retrieve records in the sequential order of the keys. The merits and efficiencies of these methods or structures are discussed in detail.展开更多
为解决快速扩展随机树算法(rapid-exploration random tree,RRT*)在三维环境中盲目搜索路径以及缺乏节点扩展记忆性等问题,提出一种融合蚁群算法的双向搜索算法ACO-RRT*。为适应精细化三维建模环境和解决地面起伏不平坦等问题,对RRT*算...为解决快速扩展随机树算法(rapid-exploration random tree,RRT*)在三维环境中盲目搜索路径以及缺乏节点扩展记忆性等问题,提出一种融合蚁群算法的双向搜索算法ACO-RRT*。为适应精细化三维建模环境和解决地面起伏不平坦等问题,对RRT*算法进行改进优化。采用双向搜索策略,在起点和终点同时运行改进后的RRT算法和蚁群算法,相向而行,对路径长度和运行时间进行优化。针对生成路径不够平滑等问题,引入B样条曲线平滑策略优化路径。仿真结果表明,所提算法能够有效用于机器人三维路径规划。展开更多
针对快速扩展随机树(rapidly-exploring random tree,RRT)算法在无人机路径规划过程中采样次数多、生成路径曲折等问题,提出了一种将路径重规划策略和平滑度优化相结合的路径规划算法。首先,通过重新构造采样区域降低RRT算法采样次数,...针对快速扩展随机树(rapidly-exploring random tree,RRT)算法在无人机路径规划过程中采样次数多、生成路径曲折等问题,提出了一种将路径重规划策略和平滑度优化相结合的路径规划算法。首先,通过重新构造采样区域降低RRT算法采样次数,利用目标偏向寻优策略为RRT算法添加导向性;其次,在筛选初始航迹点的同时引入无人机性能约束;然后,利用B样条对重规划路径进行平滑处理;最后,利用Matlab对所提出的算法进行仿真实验。实验结果为平均采样次数为386次,平均运行时间为0.43 s,平均航迹距离为1392.16(无量纲),表明了算法可有效降低采样次数并改善路径平滑性。展开更多
The Fermat–Pramanik series are like below: .The mathematical principle has been established by factorization principle. The Fermat-Pramanik tree can be grown. It produces branched Fermat-Pramanik series using same pr...The Fermat–Pramanik series are like below: .The mathematical principle has been established by factorization principle. The Fermat-Pramanik tree can be grown. It produces branched Fermat-Pramanik series using same principle making Fermat-Pramanik chain. Branched chain can be propagated at any point of the main chain with indefinite length using factorization principle as follows: Same principle is applicable for integer solutions of A<sup>M</sup>+B<sup>2</sup>=C<sup>2</sup>which produces series of the type . It has been shown that this equation is solvable with N{A, B, C, M}. where , , M=M<sub>1</sub>+M<sub>2</sub> and M<sub>1</sub>>M<sub>2</sub>. Subsequently, it has been shown that using M= M<sub>1</sub>+M<sub>2</sub>+M<sub>3</sub>+... The combinations of Ms should be taken so that the values of both the parts (C<sub>n</sub>+B<sub>n</sub>) and (C<sub>n</sub>-B<sub>n</sub>) should be even or odd for obtaining Z{B,C}. Hence, it has been shown that the Fermat triple can generate a) Fermat-Pramanik multiplate, b) Fermat-Pramanik Branched multiplate and c) Fermat-Pramanik deductive series. All these formalisms are useful for development of new principle of cryptography. .展开更多
文摘A simple fast method is given for sequentially retrieving all the records in a B tree. A file structure for database is proposed. The records in its primary data file are sorted according to the key order. A B tree is used as its dense index. It is easy to insert, delete or search a record, and it is also convenient to retrieve records in the sequential order of the keys. The merits and efficiencies of these methods or structures are discussed in detail.
文摘为解决快速扩展随机树算法(rapid-exploration random tree,RRT*)在三维环境中盲目搜索路径以及缺乏节点扩展记忆性等问题,提出一种融合蚁群算法的双向搜索算法ACO-RRT*。为适应精细化三维建模环境和解决地面起伏不平坦等问题,对RRT*算法进行改进优化。采用双向搜索策略,在起点和终点同时运行改进后的RRT算法和蚁群算法,相向而行,对路径长度和运行时间进行优化。针对生成路径不够平滑等问题,引入B样条曲线平滑策略优化路径。仿真结果表明,所提算法能够有效用于机器人三维路径规划。
文摘针对快速扩展随机树(rapidly-exploring random tree,RRT)算法在无人机路径规划过程中采样次数多、生成路径曲折等问题,提出了一种将路径重规划策略和平滑度优化相结合的路径规划算法。首先,通过重新构造采样区域降低RRT算法采样次数,利用目标偏向寻优策略为RRT算法添加导向性;其次,在筛选初始航迹点的同时引入无人机性能约束;然后,利用B样条对重规划路径进行平滑处理;最后,利用Matlab对所提出的算法进行仿真实验。实验结果为平均采样次数为386次,平均运行时间为0.43 s,平均航迹距离为1392.16(无量纲),表明了算法可有效降低采样次数并改善路径平滑性。
文摘The Fermat–Pramanik series are like below: .The mathematical principle has been established by factorization principle. The Fermat-Pramanik tree can be grown. It produces branched Fermat-Pramanik series using same principle making Fermat-Pramanik chain. Branched chain can be propagated at any point of the main chain with indefinite length using factorization principle as follows: Same principle is applicable for integer solutions of A<sup>M</sup>+B<sup>2</sup>=C<sup>2</sup>which produces series of the type . It has been shown that this equation is solvable with N{A, B, C, M}. where , , M=M<sub>1</sub>+M<sub>2</sub> and M<sub>1</sub>>M<sub>2</sub>. Subsequently, it has been shown that using M= M<sub>1</sub>+M<sub>2</sub>+M<sub>3</sub>+... The combinations of Ms should be taken so that the values of both the parts (C<sub>n</sub>+B<sub>n</sub>) and (C<sub>n</sub>-B<sub>n</sub>) should be even or odd for obtaining Z{B,C}. Hence, it has been shown that the Fermat triple can generate a) Fermat-Pramanik multiplate, b) Fermat-Pramanik Branched multiplate and c) Fermat-Pramanik deductive series. All these formalisms are useful for development of new principle of cryptography. .
