Begen, E.Sayan, İ. U.Bayrak, A. T.Yıldız, Olcay Taner2024-02-152024-02-152023979-835033890-4http://hdl.handle.net/10679/9138https://doi.org/10.1109/INISTA59065.2023.10310515Restaurant cash registers frequently experience fraudulent transactions, leading to substantial financial losses for operators. Despite several methods aimed at preventing fraud at the cash register, addressing this issue remains an ongoing concern. In this study, machine learning methods are used to detect fraudulent transactions at the cash register in fast-food restaurants. By using POS logs, transactions in restaurants are recorded and these logs are analyzed to detect fraudulent transactions on an unbalanced dataset. Random forest, XGBoost and LGBM algorithms are used in the study and different resampling techniques (ADASYN etc.) are applied to improve the performance of these algorithms. In addition, it is aimed to find the best parameters with the randomized search method. In conclusion, this study offers a solution for detecting fraudulent transactions at the cash register in fast-food restaurants. The results of the study are promising in its current state.engrestrictedAccessconferenceObject10.1109/INISTA59065.2023.10310515LgbmPoint of sale fraud detectionResamplingUnbalanced dataXgboost2-s2.0-85179550067