A concept of kernel matrix of quaternion is proposed, which is based on rotation groupalgebra and with spacecraft attitude control as its background.
基于旋转群代数，以航天器姿态控制研究为背景，提出了四元数的核心矩阵的概念。
2
The structure of the idempotent elements, regular elements and maximal subgroups and the number of the idempotent elements and regular elements in Boolean groupalgebra are given.
给出了布尔群代数半群中的幂等元、极大子群和正则元的结构以及幂等元和正则元的个数。
3
Group Explorer is mathematical visualization software for the abstract algebra classroom. Users can explore dozens of finite groups (and morphisms among them) visually and interactively.