We investigate the relations between certain bases and quasi-bases,prove that a space has finite rank base if and only if it has finite rank quasi-base,a space has an ortho-base if and only if it has an ortho-quasi-base.
我们研究了某些基与拟基的关系,证明了空间具有有限秩的基当且仅当它有有限秩的拟基,空间具有正交基当且仅当它有正交的拟基。
A new error motion measurement method is put forward based on virtual datum, with the core of "workpiece is datum".
根据数控机床运动误差检测的实时性、高效性等特点 ,提出了“工件即基准”为核心的 ,基于虚拟基准的数控机床运动误差检测方案 ,该方案具有高柔度、不需要基准件 ,可实现在机检测等优
In order to solve the shelter problem of GPS network and state control points conjunction, a method of constructing virtual vector was put forward in this thesis.
针对GPS控制网与国家控制点联测时遮挡严重的问题,提出了一种虚拟基线的方法,即通过常规方法测出GPS网中某点与国家控制点之间的基线构造元素,并利用WGS84地心坐标系与站心地平直角坐标系之间的转换模型计算出国家控制点的WGS84地心坐标,然后根据GPS商业处理软件的基线格式构造出GPS网中某点与国家控制点之间的虚拟基线,并入整个GPS控制网中进行平差解算。