Browsing Computational Mathematics (CM) by Title
Now showing items 1-20 of 368
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1.5D BASED INVERSION OF LOGGING-WHILE-DRILLING RESISTIVITY MEASUREMENTS IN 3D FORMATIONS
(2017-06)This manuscript describes an extension of a computer method developed for the fast inversion of logging-while-drilling (LWD) resistivity measurements Pardo and Torres-Verdín (2015); Bakr et al. (2016). The method enables ... -
1D Painless Multi-level Automatic Goal-Oriented h and p Adaptive Strategies Using a Pseudo-Dual Operator
(2022-01-01)The main idea of our Goal-Oriented Adaptive (GOA) strategy is based on performing global and uniform h- or p-refinements (for h- and p-adaptivity, respectively) followed by a coarsening step, where some basis functions are ... -
2.5-D Deep Learning Inversion of LWD and Deep-Sensing em Measurements Across Formations with Dipping Faults
(2022-01-01)Deep learning (DL) inversion of induction logging measurements is used in well geosteering for real-time imaging of the distribution of subsurface electrical conductivity. We develop a DL inversion workflow to solve 2.5-D ... -
3D hp-Adaptive Finite Element Simulations of Bend, Step, and Magic-T Electromagnetic Waveguide Structures
(2014-03)Metallic rectangular waveguides are often the preferred choice on telecommunication systems and medical equipment working on the upper microwave and millimeter wave frequency bands due to the simplicity of its geometry, ... -
5-axis double-flank CNC machining of spiral bevel gears via custom-shaped milling tools -- Part I: modeling and simulation
(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 ... -
5-axis double-flank CNC machining of spiral bevel gears via custom-shaped tools – Part II: physical validations and experiments
(2021-10)Recently, a new methodology for 5-axis flank computer numerically controlled (CNC) machining, called double-flank machining, has been introduced (see “5-axis double-flank CNC machining of spiral bevel gears via custom-shaped ... -
Accelerating fluid-solid simulations (Lattice-Boltzmann & Immersed-Boundary) on heterogeneous architectures
(2015-12-31)We propose a numerical approach based on the Lattice-Boltzmann (LBM) and Immersed Boundary (IB) methods to tackle the problem of the interaction of solids with an incompressible fluid flow, and its implementation on ... -
Accessibility for Line-Cutting in Freeform Surfaces
(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 ... -
Adaptive simulation of unsteady flow past the submerged part of a floating wind turbine platform
(2015-12-31)Offshore floating platforms for wind turbines represent challenging concepts for designers trying to combine an optimal compromise between cost effectiveness and performance. Modelling of the hydrodynamic behaviour of the ... -
Adaptive Solution of a Singularly-Perturbed Convection-Diffusion Problem Using a Stabilized Mixed Finite Element Method
(2019-01-05)We explore the applicability of a new adaptive stabilized dual-mixedfinite element method to a singularly-perturbed convection-diffusion equation withmixed boundary conditions. We establish the rate of convergence when the ... -
Adjoint-based formulation for computing derivatives with respect to bed boundary positions in resistivity geophysics
(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 ... -
Aeroacoustic Analysis of a Closely Installed Chevron Nozzle Jet using the High-Order Discontinuous Galerkin Method
(2023-06-08)In this paper, we use Large Eddy Simulations (LES) in combination with the Ffowcs Williams - Hawkings method to study the influence of chevrons on the flow field as well as the noise produced by a closely installed M = 0.6 ... -
Aeroacoustic Analysis of a Subsonic Jet using the Discontinuous Galerkin Method
(2022)In this work, the open-source spectral/hp element framework Nektar++ (www.nektar.info) is coupled with the Antares library (www.cerfacs.fr/antares/) to predict noise from a subsonic jet. Nektar++ uses the high-order ... -
Aerodynamic study of a tricycle wheel subsystem for drag reduction
(2014-12-31)This paper deals with a computational fluid dynamics (CFD) and experimental drag analysis on an isolated rotating wheel subsystem (including its accessories: tire, suspension, A-arms, and fender) of a motor tricycle vehicle ... -
An Agent-Oriented Hierarchic Strategy for Solving Inverse Problems
(2015-12-31)The paper discusses the complex, agent-oriented hierarchic memetic strategy (HMS) dedicated to solving inverse parametric problems. The strategy goes beyond the idea of two-phase global optimization algorithms. The global ... -
Algebraic equations for constant width curves and Zindler curves
(2022-03)An explicit method to compute algebraic equations of curves of constant width and Zindler curves generated by a family of middle hedgehogs is given thanks to a property of Chebyshev polynomials. This extends the methodology ... -
An Algorithm based on continuation techniques for minimization problems with highly non linear equality constraints
(2021)We present an algorithm based on continuation techniques that can be applied to solve numerically minimization problems with equality constraints. We focus on problems with a great number of local minima which are hard to ... -
Analysis of extreme wave events on the southern coast of Brazil
(2014-12-31)Using the wave model SWAN (simulating waves nearshore), high waves on the southwestern Atlantic generated by extra-tropical cyclones are simulated from 2000 to 2010, and their impact on the Rio Grande do Sul (RS) coast is ... -
Apparent slip mechanism between two spheres based on solvent rheology: Theory and implication for the shear thinning of non-Brownian suspensions
(2018-12-10)Analytical results for the apparent slip between two spheres in a simple biviscous model of a shear thinning fluid are presented. Velocity profiles and apparent slip lengths along the surfaces are analyzed in order to ...