Deng entropy and extropy are two measures useful in the Dempster-Shafer evidence theory (DST) to study uncertainty, following the idea that extropy is the dual concept of entropy. In this paper, we present their fractional versions named fractional Deng entropy and extropy and compare them to other measures in the framework of DST. Here, we study the maximum for both of them and give several examples. Finally, we analyze a problem of classification in pattern recognition in order to highlight the importance of these new measures.
Keywords: Deng entropy and extropy; classification and discrimination; fractional entropy; measures of uncertainty.