面向轨迹大数据的压缩空间算法研究

大量定位技术和移动技术的成熟为多源、多模态数据的增加奠定了基础,其中有关运动物体轨迹的GPS轨迹数据增长尤为突出。因此,提出了一种路网轨道压缩算法。首先,在预处理步骤中,将轨迹分解为空间路径和时间序列。其次,在压缩步骤中,设计对空间路径执行空间压缩的算法,以及对时间序列并行执行时间压缩的算法。

Solving Incompressible internal Flow Fields in Thrbomachinerywith Time Marching Algorithms

A time marching algorithms, which is used to solve incompressible internal flow fields in turbomachinery, has beendeveloped. By using Chorin’s method of artificial compressibility, the governing equations are transformed fromelliptic type into hyperbolic form in order to extend the time marching technique to very low Mach number flows.Viscous effects can be predicted by using the distributed body force method and Baldwin-Lomax eddy viscosityturbulence model. Some accelerating convergence techniques such as multi-grid and local time step method areemployed. The applicahon to a flow field within a low-solidity rocket pump inducer is presented and discussed.