With some popular tracking methods for free surface, simulations of several typical examples are carried out under various flow field conditions. The results show that the Smoothed Particle Hydrodynamics （SPH） metho...With some popular tracking methods for free surface, simulations of several typical examples are carried out under various flow field conditions. The results show that the Smoothed Particle Hydrodynamics （SPH） method is very suitable in simulating the flow problems with a free surface. A viscous liquid droplet with an initial velocity impacting on a solid surface is simulated based on the SPH method, and the surface tension is considered by searching the free surface particles, the initial impact effect is considered by using the artificial viscosity method, boundary virtual particles and image virtual particles are introduced to deal with the boundary problem, and the boundary defect can be identified quite well. The comparisons of simulated results and experimental photographs show that the SPH method can not only exactly simulate the spreading process and the rebound process of a liquid droplet impacting on a solid surface but also accurately track the free surface particles, simulate the free-surface flow and determine the shape of the free surface due to its particle nature.展开更多
针对Top-k高效用项集挖掘算法在挖掘过程中忽略内存管理的问题,提出基于DBP的Top-k高效用项集挖掘算法TKBPH(Top-k buffer pool high utility itemsets mining),采用数据缓冲池(DBP)结构存储效用链表,并由索引链表记录效用链表在DBP的...针对Top-k高效用项集挖掘算法在挖掘过程中忽略内存管理的问题,提出基于DBP的Top-k高效用项集挖掘算法TKBPH(Top-k buffer pool high utility itemsets mining),采用数据缓冲池(DBP)结构存储效用链表,并由索引链表记录效用链表在DBP的位置。数据缓冲池根据挖掘过程情况在数据缓冲池尾部动态插入和删除效用链表,通过索引链表直接读取效用链表避免项集搜索时频繁的比较操作,有效减少内存空间和运行时间消耗。不同类型数据集上的实验结果表明,TKBPH算法在挖掘过程中执行速度更快、内存消耗更少。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.51079095)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(Grant No.51021004)
文摘With some popular tracking methods for free surface, simulations of several typical examples are carried out under various flow field conditions. The results show that the Smoothed Particle Hydrodynamics （SPH） method is very suitable in simulating the flow problems with a free surface. A viscous liquid droplet with an initial velocity impacting on a solid surface is simulated based on the SPH method, and the surface tension is considered by searching the free surface particles, the initial impact effect is considered by using the artificial viscosity method, boundary virtual particles and image virtual particles are introduced to deal with the boundary problem, and the boundary defect can be identified quite well. The comparisons of simulated results and experimental photographs show that the SPH method can not only exactly simulate the spreading process and the rebound process of a liquid droplet impacting on a solid surface but also accurately track the free surface particles, simulate the free-surface flow and determine the shape of the free surface due to its particle nature.
文摘针对Top-k高效用项集挖掘算法在挖掘过程中忽略内存管理的问题,提出基于DBP的Top-k高效用项集挖掘算法TKBPH(Top-k buffer pool high utility itemsets mining),采用数据缓冲池(DBP)结构存储效用链表,并由索引链表记录效用链表在DBP的位置。数据缓冲池根据挖掘过程情况在数据缓冲池尾部动态插入和删除效用链表,通过索引链表直接读取效用链表避免项集搜索时频繁的比较操作,有效减少内存空间和运行时间消耗。不同类型数据集上的实验结果表明,TKBPH算法在挖掘过程中执行速度更快、内存消耗更少。
