Freeform optics can be used to greatly extend the functionalities, improve performance, and reduce volume weight of optical systems. Today, design imaging systems largely relies on efficient ray tracing optimization algorithms. Such a "step-and-repeat" approach typically requires considerable experience, intuition, eventually "trial-and-error" guesswork. This time-consuming process applies espe...

in this paper we present a method to perform flood frequency analysis (ffa) when the assumption of stationary is not important (or not valid). a wavelet transform model is developed to ffa. a full series is applied to ffa using two different wavelet functions, and then a combined method is investigated. in the combined method, all discharge data which were less than the lowest value of annual m...