Now showing items 1-20 of 900

• #### Tissue drives lesion: computational evidence of interspecies variability in cardiac radiofrequency ablation ﻿

(HE 10TH INTERNATIONAL CONFERENCE ON FUNCTIONAL IMAGING AND MODELING OF THE HEART, 2019)
Radiofrequency catheter ablation (RFCA) is widely used for the treatment of various types of cardiac arrhythmias. Typically, the efficacy and the safety of the ablation protocols used in the clinics are derived from tests ...
• #### Bloom type upper bounds in the product BMO setting ﻿

(Journal of Geometric Analysis, 2019-04-08)
We prove some Bloom type estimates in the product BMO setting. More specifically, for a bounded singular integral $T_n$ in $\mathbb R^n$ and a bounded singular integral $T_m$ in $\mathbb R^m$ we prove that  \| [T_n^1, ...
• #### Convex Integration Arising in the Modelling of Shape-Memory Alloys: Some Remarks on Rigidity, Flexibility and Some Numerical Implementations ﻿

(Journal of Nonlinear Science, 2019-03-30)
We study convex integration solutions in the context of the modelling of shape-memory alloys. The purpose of the article is twofold, treating both rigidity and flexibility prop- erties: Firstly, we relate the maximal ...
• #### Adjoint-based formulation for computing derivatives with respect to bed boundary positions in resistivity geophysics ﻿

(Computational Geosciences, 2019-02)
In inverse geophysical resistivity problems, it is common to optimize for specific resistivity values and bed boundary positions, as needed, for example, in geosteering applications. When using gradient-based inversion ...
• #### Topological singular set of vector-valued maps, I: application to manifold-constrained Sobolev and BV spaces ﻿

(Calculus of Variations and Partial Differential Equations, 2019-03-30)
We introduce an operator $\mathbf{S}$ on vector-valued maps $u$ which has the ability to capture the relevant topological information carried by $u$. In particular, this operator is defined on maps that take values in a ...
• #### Order Reconstruction for neatics on squares with isotropic inclusions: A Landau-de Gennes study ﻿

(SIAM Journal on Applied Mathematics, 2019-03-30)
e study a modified Landau-de Gennes model for nematic liq- uid crystals, where the elastic term is assumed to be of subquadratic growth in the gradient. We analyze the behaviour of global minimizers in two- and three-dimensional ...
• #### A C0 interior penalty discontinuous Galerkin method for fourth‐order total variation flow I: Derivation of the method and numerical results ﻿

(NMPDE:Numerical Methods For Partial Differential Equations, 2019-02-23)
We consider the numerical solution of a fourth‐order total variation flow problem representing surface relaxation below the roughening temperature. Based on a regularization and scaling of the nonlinear fourth‐order parabolic ...
• #### A C 0 interior penalty discontinuous Galerkin Method for fourth-order total variation flow. II: Existence and uniqueness ﻿

(NMPDE:Numerical Methods For Partial Differential Equations, 2019-02-25)
We prove the existence and uniqueness of a solution of a C0 Interior Penalty Discontinuous Galerkin (C0 IPDG) method for the numerical solution of a fourth‐order total variation flow problem that has been developed in part ...
• #### Parallel refined Isogeometric Analysis in 3D ﻿

(IEEE Transactions on Parallel and Distributed Systems, 2018-11)
We study three-dimensional isogeometric analysis (IGA) and the solution of the resulting system of linear equations via a direct solver. IGA uses highly continuous $C^{p-1}$ basis functions, which provide multiple benefits ...
• #### Asymptotic Models for the Electric Potential across a Highly Conductive Casing ﻿

(Computers and Mathematics with Applications, 2018-07)
We analyze a configuration that involves a steel-cased borehole, where the casing that covers the borehole is considered as a highly conductive thin layer. We develop an asymptotic method for deriving reduced problems ...
• #### On initialization of milling paths for 5-axis flank CNC machining of free-form surfaces with general milling tools ﻿

(Computer Aided Geometric Design (CAGD, Elsevier), 2019-03-27)
We propose a path-planning algorithm for 5-axis flank CNC machining with general tools of varying curvature. Our approach generalizes the initialization strategy introduced for conical tools [Bo et al., 2017] to arbitrary ...
• #### Stochastic spatial models in ecology: a statistical physics approach ﻿

(Journal of Statistical Physics, 2017-11-21)
Ecosystems display a complex spatial organization. Ecologists have long tried to characterize them by looking at how different measures of biodiversity change across spatial scales. Ecological neutral theory has provided ...
• #### A space-time DPG method for the wave equation in multiple dimensions ﻿

(RICAM book series, 2019)
A space-time discontinuous Petrov–Galerkin (DPG) method for the linear wave equation is presented. This method is based on a weak formulation that uses a broken graph space. The well-posedness of this formulation is ...
• #### Fast inversion of logging-while-drilling resistivity measurements acquired in multiple wells ﻿

(Geophysics, 2016-10)
This paper introduces a new method for the fast inversion of borehole resistivity measurements acquired in multiple wells using logging-while-drilling (LWD) instruments. There are two key novel contributions. First, we ...
• #### Finite element approximation of electromagnetic fields using nonfitting meshes for Geophysics ﻿

(SIAM Journal on Numerical Analysis, 2018-07)
We analyze the use of nonfitting meshes for simulating the propagation of electromagnetic waves inside the earth with applications to borehole logging. We avoid the use of parameter homogenization and employ standard edge ...
• #### Time-Domain Goal-Oriented Adaptivity Using Pseudo-Dual Error Representations ﻿

(Computer Methods in Applied Mechanics and Engineering, 2017-12)
Goal-oriented adaptive algorithms produce optimal grids to solve challenging engineering problems. Recently, a novel error representation using (unconventional) pseudo-dual problems for goal-oriented adaptivity in the ...
• #### Bloom type inequality for bi-parameter singular integrals: efficient proof and iterated commutators ﻿

(International Mathematics Research Notices, 2019-03-14)
Utilising some recent ideas from our bilinear bi-parameter theory, we give an efficient proof of a two-weight Bloom type inequality for iterated commutators of linear bi-parameter singular integrals. We prove that if $T$ ...
• #### Fractional kinetics in random/complex media ﻿

(Handbook of Fractional Calculus with Applications Volume 5 Applications in Physics, Part B, 2019)
In this chapter, we consider a randomly-scaled Gaussian process and discuss a number of applications to model fractional diffusion. Actually, this approach can be understood as a Gaussian diffusion in a medium characterized ...
• #### Fractional Brownian motion in a finite interval: correlations effect depletion or accretion zones of particles near boundaries ﻿

(New Journal of Physics, 2019-02)
Fractional Brownian motion (FBM) is a Gaussian stochastic process with stationary, long-time correlated increments and is frequently used to model anomalous diffusion processes. We study numerically FBM confined to a finite ...
• #### Boundary Triples for the Dirac Operator with Coulomb-Type Spherically Symmetric Perturbations ﻿

(Journal of Mathematical Physics, 2019-02)
We determine explicitly a boundary triple for the Dirac operator $H:=-i\alpha\cdot \nabla + m\beta + \mathbb V(x)$ in $\mathbb R^3$, for $m\in\mathbb R$ and \$\mathbb V(x)= |x|^{-1} ( \nu \mathbb{I}_4 +\mu \beta -i \lambda ...