Update visitors.yml

Author: wangc168

_data/members/visitors.yml

@@ -1,7 +1,7 @@
 - name: "[Changchang Sun](https://scholar.google.com/citations?user=bCxWjjYAAAAJ&hl=en) (Visiting)"
   info: Ph.D. student, Department of Computer Science, University of Illinois Chicago 
   visiting: Aug. 2023 - May. 2025
-  research:
+  research: "<a href='https://arxiv.org/abs/2412.16780'>Forget Vectors at Play: Universal Input Perturbations Driving Machine Unlearning in Image Classification</a>"
 
 - name: Yuhao Sun (remote)
   info: Graduate student, University of Science and Technology of China