We study a nonlinear elliptic boundary value problem arising from electrochemistry in the study of heterogeneous electrode surfaces. The boundary condition is of exponential type (Butler–Volmer) and has a periodic structure. We find a limiting or effective problem as the period approaches zero, along with a first order correction. We establish convergence estimates and provide numerical experim...

The boundary slip error resulting from the interpolation/spreading non-reciprocity of direct-forcing immersed-boundary method is analyzed based on a simple and generic theoretical framework. In explicit implementations, scales with Courant number, as predicted by analysis confirmed lattice-Boltzmann simulation results. Using an analytical approximation error, force can be corrected in order to ...

We consider practical density estimation from large data sets sampled on manifolds embedded in Euclidean space. Existing density estimators on manifolds typically require prior knowledge of the geometry of the manifold, and all density estimation on embedded manifolds is restricted to compact manifolds without boundary. First, motivated by recent developments in kernel-based manifold learning, ...

A novel immersed boundary velocity correction–lattice Boltzmann method is presented and validated in this work by its application to simulate the two-dimensional flow over a circular cylinder. The present approach is inspired from the conventional immersed boundary method (IBM). In the conventional IBM, the effect of rigid body on the surrounding flow is modeled through a forcing term, which is...

This paper examines and develops matrix methods to approximate the eigenvalues of a fourth order Sturm-Liouville problem subjected to a kind of fixed boundary conditions, furthermore, it extends the matrix methods for a kind of general boundary conditions. The idea of the methods comes from finite difference and Numerov’s method as well as boundary value methods for second order regular Sturm-L...

In the numerical treatment of integral equations of the first kind using boundary element methods (BEM), the author and E. P. Stephan have derived a posteriori error estimates as tools for both reliable computation and self-adaptive mesh refinement. So far, efficiency of those a posteriori error estimates has been indicated by numerical examples in model situations only. This work affirms effic...

The flux of vorticity from a piston-cylinder vortex generator is commonly approximated using a model in which the fluid efflux is treated as a uniform slug of fluid with negligible boundary layer thickness. Shusser et al. (2002) introduced a correction to the slug model that accounts for boundary layer growth within the cylinder. We show that their implemented boundary layer solution contains a...

The first term is the estimation error and measures the performance of the discrimination rule with respect to the best hypothesis in H. In previous lectures, we studied performance guarantees for this quantity when ĥn is ERM. Now, we also consider the approximation error, which captures how well a class of hypotheses {Hk} approximates the Bayes decision boundary. For example, consider the hist...

We present a new algorithm, the Time Dependent Phase Space Filter (TDPSF) which is used to solve time dependent Nonlinear Schrodinger Equations (NLS). The algorithm consists of solving the NLS on a box with periodic boundary conditions (by any algorithm). Periodically in time, we decompose the solution into a family of coherent states. Those coherent states which are outgoing are deleted, while...