Nonnegative Matrix Factorization (NMF) is the problem of approximating a nonnegative matrix with the product of two low-rank nonnegative matrices and has been shown to be particularly useful in many applications, e.g., in text mining, image processing, computational biology, etc. In this paper,...

Предлагаются многосеточные варианты иерархических методов моделирования распределения потоков для оптимизации нестационарных режимов транспорта газа на...

Many optimization algorithms require gradients of the model functions, but computing accurate gradients can be computationally expensive. We study the implications of using inexact gradients in the context of the multilevel optimization algorithm <Emphasis Type="SmallCaps">MG/Opt. <Emphasis Type="SmallCaps">MG/Opt recursively uses (typically...</emphasis></emphasis>