Prof. Xuehou Tan, who comes from the Tokai University, visited the CFC on May 18th. And he gave two lectures on “An Introduction to Computational Geometry: Geometric Algorithms and Their Applications” and “Recent Results on Visibility and Shortest Paths in Polygonal Regions”, respectively. Prof. Tan’s lectures made details in the algorithm and applications of Computational Geometry. He also introduced his research on the Computational Geometry.