SubmissionNumber#=%=#72 FinalPaperTitle#=%=#Team QUST at SemEval-2024 Task 8: A Comprehensive Study of Monolingual and Multilingual Approaches for Detecting AI-generated Text ShortPaperTitle#=%=# NumberOfPages#=%=#8 CopyrightSigned#=%=#Xiaoman Xu JobTitle#==# Organization#==#QUST Qingdao University of Science and Technology, Qingdao, Shandong Province, China Abstract#==#This paper presents the participation of team QUST in Task 8 SemEval 2024. we first performed data augmentation and cleaning on the dataset to enhance model training efficiency and accuracy. In the monolingual task, we evaluated traditional deep-learning methods, multiscale positive-unlabeled framework (MPU), fine-tuning, adapters and ensemble methods. Then, we selected the top-performing models based on their accuracy from the monolingual models and evaluated them in subtasks A and B. The final model construction employed a stacking ensemble that combined fine-tuning with MPU. Our system achieved 6th (scored 6th in terms of accuracy, officially ranked 13th in order) place in the official test set in multilingual settings of subtask A. We release our system code at:https://github.com/warmth27/SemEval2024_QUST Author{1}{Firstname}#=%=#Xiaoman Author{1}{Lastname}#=%=#Xu Author{1}{Email}#=%=#xxm.981215@gmail.com Author{1}{Affiliation}#=%=#Qingdao University of Science and Technology Author{2}{Firstname}#=%=#Xiangrun Author{2}{Lastname}#=%=#Li Author{2}{Email}#=%=#15288825435@163.com Author{2}{Affiliation}#=%=#Qingdao University of Science and Technology Author{3}{Firstname}#=%=#Taihang Author{3}{Lastname}#=%=#Wang Author{3}{Email}#=%=#thang20@163.com Author{3}{Affiliation}#=%=#Qingdao University of Science and Technology Author{4}{Firstname}#=%=#Jianxiang Author{4}{Lastname}#=%=#Tian Author{4}{Email}#=%=#wwxy.mail@gmail.com Author{4}{Affiliation}#=%=#Qingdao University of Science and Technology Author{5}{Firstname}#=%=#Ye Author{5}{Lastname}#=%=#Jiang Author{5}{Email}#=%=#ye.jiang@qust.edu.cn Author{5}{Affiliation}#=%=#Qingdao University of Science and Technology ========== èéáğö