A Note on the Analysis of (Q.r) Policy : GLD Approximation vs Distribution Free Approach
In this article, we consider the analysis of a continuous review (Q, r) inventory model with a mixture of back orders and lost sales, assuming Weibull distribution for the lead time demand (LTD). The use of generalized λ-type distribution (GLD) in approximating the LTD is demonstrated. Through numerical studies, optimal values of the policy parameters are obtained under GLD approximation method, the distribution free approach, and the exact case. Further, the expected value of additional information (EVAI) which serves as a measure of efficiency of the procedure is provided for both the GLD and the distribution free procedures.
We address the problem of comparing the performance of classifiers. In this paper we study techniques for generating and evaluating bands on ROC curves. Historically this has been done using one-dimensional confidence intervals by freezing one variable - false-positiverate, or threshold on the classification scoring function. Weadapt two prior methods and introduce a new radial sweepmethod to generate confidence bands. We show, throughempirical studies, that the bands are too tight and introducea general optimization methodology for creatingbands that better fit the data, as well as methods for evaluatingconfidence bands. We show empirically that theoptimized confidence bands fit much better and that, usingour new evaluation method, it is possible to gauge therelative fit of different confidence bands.