vector invariant

Studied the actions of Lie groupoids on its Inner subgroupoids, proved the result that its Maurer-Cartan forms acting on left invariant vector field is a constant.

研究了李群胚在其内子群胚上的作用，并证明了李群胚上的Maurer-cartan形式在其任意左不变向量场上作用的结果为常数。

a vector invariant on tetrahedron and its deductions

关于四面体的一个向量恒等式及其推论

In line with characteristics of human motion, we can combine space-time invariant physical structure parameters of moving human with Time-varying motion parameters, making up a periodic eigen vector template.

根据人体运动特性，将运动人体时空不变的身体结构参数和随时空变化的动态参数结合起来，构造一个周期的特征向量模板。

Presents new vector matrix form formulas for solving linear time invariant state equations.

提出了求解线性非时变状态方程的新公式。