In this paper we present a discrete adjoint approach for the optimization of unsteady, turbulent flows. While discrete adjoint methods usually rely on the use of the reverse mode of Automatic Differentiation (AD), which is difficult to apply to complex unsteady problems, our approach is based on the discrete adjoint equation directly and can be implemented efficiently with the use of a sparse f...

We apply a new industrial strength numerical approximation, called the “mesh-free adjoint method,” to solve the nonlinear filtering problem. This algorithm exploits the smoothness of the problem, unlike particle filters, and hence we expect that mesh-free adjoints are superior to particle filters for many practical applications. The nonlinear filter problem is equivalent to solving the Fokker-P...

This paper presents a nite element algorithm based on the adjoint method for the design of a certain class of solidi cation processes. In particular, the paper addresses the design of directional solidi cation processes for pure materials such that a desired freezing front heat ux and growth velocity are achieved. This is the rst time that an in nite-dimensional continuum adjoint formulation is...

An inverse spectral problem for the Sturm-Liouville operator with a singular potential from class $W_2^{-1}$ is solved by method of mappings. We prove uniqueness theorem, develop constructive algorithm solution and obtain necessary sufficient conditions solvability in self-adjoint non-self-adjoint cases.

This paper deals with the application of the adjoint transport theory in order to optimize Monte Carlo based radiotherapy treatment planning. The technique is applied to Boron Neutron Capture Therapy where most often mixed beams of neutrons and gammas are involved. In normal forward Monte Carlo simulations the particles start at a source and lose energy as they travel towards the region of inte...

We give a mathematically rigorous analysis which confirms the surprising results in a recent paper [2] of Benilov, O’Brien and Sazonov about the spectrum of a highly singular non-self-adjoint operator that arises in a problem in fluid mechanics. MSC-class: 34Lxx, 76Rxx, 65F15, 65Q05 keywords: spectrum, non-self-adjoint, fluid mechanics, pseudospectra, eigenvalue, basis.

In this work, we present two recent developments in goaloriented error estimation applied to finite element simulations. The first one is a non-intrusive enrichment of the adjoint solution using handbook techniques, inserting locally the (generalized) Green functions associated with the quantity of interest under study. The second one is a new bounding technique, based on homothetic domains, th...

Research considered investigates the optimal control problem which is constrained by a hyperbolic conservation law (HCL). We carried out a comparative study of the solutions of the optimal control problem subject to each one of the two different types of hyperbolic relaxation systems [64, 92]. The objective was to employ the adjoint-based optimization to minimize the cost functional of a matchi...

The secular variation of the geomagnetic field as observed at the Earth's surface results from the complex magnetohydrodynamics taking place in the fluid core of the Earth. One way to analyze this system is to use the data in concert with an underlying dynamical model of the system through the technique of variational data assimilation, in much the same way as is employed in meteorology and oce...

An object $X$ of a category $mathbf{C}$ with finite limits is called exponentiable if the functor $-times X:mathbf{C}rightarrow mathbf{C}$ has a right adjoint. There are many characterizations of the exponentiable  spaces in the category $mathbf{Top}$ of topological spaces. Here, we study the exponentiable objects in the category $mathbf{STop}$ of soft topological spaces which is a generalizati...