projective group

Study on the Group Personality Projective Test in China

团体个性投射测验（GPPT）的初步试测报告

A group of projective invariants was derived based on the cross ratio of five coplanar points, and used to recognize planar polygons. Experimental results show that the invariants have projective invariance and can be used to recognize planar polygons effectively.

利用共面五点的交比，导出一组用于识别平面多边形的射影不变量，用这组不变量实现平面多边形的识别，实验结果表明，这组不变量具有射影不变性，可以有效地识别平面多边形。

The main result: Let q be a power of a prime, and if G is a collineation group of a projective plane and G acts transitively on the points, then G is not isomorphic to PSU ( 3, q~ 2).

得到主要结果：令q是素数方幂，若G是一个射影平面的共线变换群并且传递地作用在点集合上，则G不能与PSU（3，q2）同构。