### Recent Submissions

• #### 5-axis double-flank CNC machining of spiral bevel gears via custom-shaped milling tools -- Part I: modeling and simulation ﻿

(Precision Engineering, 2019-11-20)
A new category of 5-axis flank computer numerically controlled (CNC) machining, called \emph{double-flank}, is presented. Instead of using a predefined set of milling tools, we use the shape of the milling tool as a free ...
• #### Refined Isogeometric Analysis for fluid mechanics and electromagnetism ﻿

(Computer Methods in Applied Mechanics and Engineering, 2019-03)
Starting from a highly continuous isogeometric analysis discretization, we introduce hyperplanes that partition the domain into subdomains and reduce the continuity of the discretization spaces at these hyperplanes. As the ...
• #### Efficient mass and stiffness matrix assembly via weighted Gaussian quadrature rules for B-splines ﻿

(Journal of Computational and Applied Mathematics, 2019-12-14)
Calabr{\`o} et al. [10] changed the paradigm of the mass and stiffness computation from the traditional element-wise assembly to a row-wise concept, showing that the latter one offers integration that may be orders of ...
• #### Studies on knot placement techniques for the geometry construction and the accurate simulation of isogeometric spatial curved beams ﻿

(Computer Methods in Applied Mechanics and Engineering, 2019-11)
The present paper investigates the use of different knot placement techniques for isogeometric analysis of spatial curved beams, to enhance analysis results in cases when geometries are given in terms of data points. ...
• #### On the application of isogeometric finite volume method in numerical analysis of wet-steam flow through turbine cascades ﻿

(Computers and Mathematics with Applications, 2019-10)
The isogeometric finite volume analysis is utilized in this research to numerically simulate the two-dimensional viscous wet-steam flow between stationary cascades of a steam turbine for the first time. In this approach, ...
• #### Explicit-in-Time Variational Formulations for Goal-Oriented Adaptivity ﻿

(2019-10)
Goal-Oriented Adaptivity (GOA) is a powerful tool to accurately approximate physically relevant features of the solution of Partial Differential Equations (PDEs). It delivers optimal grids to solve challenging engineering ...
• #### Variational Formulations for Explicit Runge-Kutta Methods ﻿

(Finite Elements in Analysis and Design, 2019-08)
Variational space-time formulations for partial di fferential equations have been of great interest in the last decades, among other things, because they allow to develop mesh-adaptive algorithms. Since it is known ...
• #### Using Covariance Matrix Adaptation Evolutionary Strategy to boost the search accuracy in hierarchic memetic computations ﻿

(Journal of Computational Science, 2019-04)
Many global optimization problems arising naturally in science and engineering exhibit some form of intrinsic ill-posedness, such as multimodality and insensitivity. Severe ill-posedness precludes the use of standard ...
• #### Snapshots location for Reduced Order Models: An approach based on Proper Orthogonal Decomposition and Mesh Adaptivity Techniques ﻿

(2019-06-28)
Solving Partial Differential Equations (PDE), is a key issue in science and engineering since they are widely used in many real problem modelling including fluid mechanics, acoustics, heat and mass transfer ...etc. Exact ...
• #### Forward-in-Time Goal-Oriented Adaptivity ﻿

(International Journal for Numerical Methods in Engineering, 2019-03)
In goal-oriented adaptive algorithms for partial differential equations, we adapt the finite element mesh in order to reduce the error of the solution in some quantity of interest. In time-dependent problems, this adaptive ...
• #### Accessibility for Line-Cutting in Freeform Surfaces ﻿

(Computer-Aided Design, 2019-04-26)
Manufacturing techniques such as hot-wire cutting, wire-EDM, wire-saw cutting, and flank CNC machining all belong to a class of processes called line-cutting where the cutting tool moves tangentially along the reference ...
• #### 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 ...
• #### 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 ...
• #### 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 ...
• #### Explicit-in-Time Goal-Oriented Adaptivity ﻿

(Computer Methods in Applied Mechanics and Engineering, 2019-04-15)
Goal-oriented adaptivity is a powerful tool to accurately approximate physically relevant solution features for partial differential equations. In time dependent problems, we seek to represent the error in the quantity of ...