On May 24th, three students from the labs Zhu Shuai, Yuan Shuai and Shi Gege respectively gave a thesis defense on the ‘Hierarchical Construction and Analysis Method of Road Networks Based on Geometric Algebra ’, ‘ynamic Evacuation Method of Multi-targets under Scene Constraints based on Geometric Algebra’, and ‘Geometric algebra expression and analytic method of geography object semantics’ conferences in the 23rd conference room of the Academy of Sciences. All the students passed the assessment smoothly.