Now showing items 63-82 of 204

• #### Fast 1D Inversion of Logging-While-Drilling Resistivity Measurements for Improved Estimation of Formation Resistivity in High-Angle and Horizontal Wells ﻿

(2014-12)
We have developed an efficient inversion method to estimate layer-by-layer electric resistivity from loggingwhile-drilling electromagnetic induction measurements. The method assumes a 1D model based on planarly layered ...
• #### Fast 2.5D Finite Element Simulations of Borehole Resistivity Measurements ﻿

(2018-05-29)
We develop a rapid 2.5-dimensional (2.5D) finite element method for simulation of borehole resistivity measurements in transversely isotropic (TI) media. The method combines arbitrary high-order $H^1$ - and $H$ (curl)-conforming ...
• #### FAST AND AUTOMATIC INVERSION OF LWD RESISTIVITY MEASUREMENTS FOR PETROPHYSICAL INTERPRETATION ﻿

(2015-07)
This paper describes an extension of a recently developed fast inversion method (Pardo and Torres-VerdÍn (2015)) for estimating a layer-by-layer electric resistivity distribution from logging-whiledrilling (LWD) electromagnetic ...
• #### Fast inversion of logging-while-drilling resistivity measurements acquired in multiple wells ﻿

(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 ...
• #### Fast One-dimensional Finite Element Approximation of Geophysical Measurements ﻿

(2018)
There exist a wide variety of geophysical prospection methods. In this work, we focus on resistivity methods. We categorize these resistivity prospection methods according to their acquisition location as (a) on the surface, ...
• #### Fast Simulation of 2.5D LWD Resistivity Tools ﻿

(2017-06)
As a first step towards the fast inversion of geophysical data, in this work we focus on the rapid simulations of 2.5D logging-while-drilling (LWD) borehole resistivity measurements. Given a commercial logging instrument ...
• #### Fast simulation of through-casing resistivity measurements using semi-analytical asymptotic models. Part 1: Accuracy study ﻿

(2014-12-31)
When trying to obtain a better characterization of the Earth's subsurface, it is common to use borehole through-casing resistivity measurements. It is also common for the wells to be surrounded by a metal casing to protect ...
• #### Finite element approximation of electromagnetic fields using nonfitting meshes for Geophysics ﻿

(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 ...
• #### A Finite Element based Deep Learning solver for parametric PDEs ﻿

(2021)
We introduce a dynamic Deep Learning (DL) architecture based on the Finite Element Method (FEM) to solve linear parametric Partial Differential Equations(PDEs). The connections between neurons in the architecture mimic the ...
• #### Finite Element Simulations of Logging-While-Drilling and Extra-Deep Azimuthal Resistivity Measurements using Non-Fitting Grids ﻿

(2018-04-27)
We propose a discretization technique using non-fitting grids to simulate magnetic field-based resistivity logging measurements. Non-fitting grids are convenient because they are simpler to generate and handle than fitting ...
• #### Forward-in-Time Goal-Oriented Adaptivity ﻿

(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 ...
• #### Fourier finite element modeling of light emission in waveguides: 2.5-dimensional FEM approach ﻿

(2015-12-31)
We present a Fourier finite element modeling of light emission of dipolar emitters coupled to infinitely long waveguides. Due to the translational symmetry, the three-dimensional (3D) coupled waveguide-emitter system can ...
• #### Fractional Laguerre spectral methods and their applications to fractional differential equations on unbounded domain ﻿

(2015-12-31)
In this article, we first introduce a singular fractional Sturm-Liouville problem (SFSLP) on unbounded domain. The associated fractional differential operator is both Weyl and Caputo type. The properties of spectral data ...
• #### FREE-FORM TOOLS DESIGN AND FABRICATION FOR FLANK SUPER ABRASIVE MACHINING (FSAM) NON DEVELOPABLE SURFACES ﻿

(2019)
Manufacturing improvements are becoming a real need in industry. In order to satisfy these industrial requirements, they should be targeted in two different directions: new manufacturing processes and surface optimization ...
• #### Fusion-based variational image dehazing ﻿

(2017-02-01)
We propose a novel image-dehazing technique based on the minimization of two energy functionals and a fusion scheme to combine the output of both optimizations. The proposed fusion-based variational image-dehazing (FVID) ...
• #### Gauss-Galerkin quadrature rules for quadratic and cubic spline spaces and their application to isogeometric analysis ﻿

(2016-07-01)
We introduce Gaussian quadrature rules for spline spaces that are frequently used in Galerkin discretizations to build mass and stiffness matrices. By definition, these spaces are of even degrees. The optimal quadrature ...
• #### Gaussian quadrature for $C^1$ cubic Clough-Tocher macro-triangles ﻿

(2018-10-31)
A numerical integration rule for multivariate cubic polynomials over n-dimensional simplices was designed by Hammer and Stroud [14]. The quadrature rule requires n + 2 quadrature points: the barycentre of the simplex and ...
• #### Gaussian quadrature rules for $C^1$ quintic splines with uniform knot vectors ﻿

(2017-03-22)
We provide explicit quadrature rules for spaces of $C^1$ quintic splines with uniform knot sequences over finite domains. The quadrature nodes and weights are derived via an explicit recursion that avoids numerical solvers. ...
• #### Generalization of the Pythagorean Eigenvalue Error Theorem and its Application to Isogeometric Analysis ﻿

(2018-10-13)
This chapter studies the effect of the quadrature on the isogeometric analysis of the wave propagation and structural vibration problems. The dispersion error of the isogeometric elements is minimized by optimally blending ...
• #### Generalization of the Zlámal condition for simplicial finite elements in ℝ d ﻿

(2011-12-31)
The famous Zlámal's minimum angle condition has been widely used for construction of a regular family of triangulations (containing nondegenerating triangles) as well as in convergence proofs for the finite element method ...