2 Credit Card Fraud Detection using Hidden Markov ... - Wiphala.net

This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication.IEEE TRANSACTIONS ON DEPEDABLE AND SECURE COMPUTINGtransaction amount ranges in the transactions. It may be noted that for cardholders in the othertwo groups, namely, high spending and medium spending, will show similar performance as onlythe relative ordering of a, b and c will change. We also vary the mean value μ of malicioustransactions from 0.5 to 4.0 in steps of 0.5. The σ value is kept fixed at 0.5 for all theexperiments. Thus, every sequence of transaction that we use for testing is a mixed sequencecontaining both genuine as well as malicious transactions. For each combination of spendingprofile and malicious transaction distribution, we carried out 100 runs and report the averageresult. The same set of data was used to determine the performance of both OA and ST.Figure 5(a) shows the variation of TP and FP for the two approaches using the spendingprofile (95 3 2). Variation of TP-FP and Accuracy is shown in Figure 5(b).80TP_OA TP_ST FP_OA FP_STTP and FP (%)60402000.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0Malicious Transaction Distribution Mean5(a)25