Now showing items 21-40 of 206

• #### On numerical solution of Fredholm and Hammerstein integral equations via Nystr\"{o}m method and Gaussian quadrature rules for splines ﻿

(2022-01)
Nystr\"{o}m method is a standard numerical technique to solve Fredholm integral equations of the second kind where the integration of the kernel is approximated using a quadrature formula. Traditionally, the quadrature ...
• #### Deep learning enhanced principal component analysis for structural health monitoring ﻿

(2022-01-01)
This paper proposes a Deep Learning Enhanced Principal Component Analysis (PCA) approach for outlier detection to assess the structural condition of bridges. We employ partially explainable autoencoder architecture to ...
• #### Error representation of the time-marching DPG scheme ﻿

(2022-03-01)
In this article, we introduce an error representation function to perform adaptivity in time of the recently developed time-marching Discontinuous Petrov–Galerkin (DPG) scheme. We first provide an analytical expression for ...
• #### 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 ...
• #### Modeling extra-deep electromagnetic logs using a deep neural network ﻿

(2021-05)
Modern geosteering is heavily dependent on real-time interpretation of deep electromagnetic (EM) measurements. We have developed a methodology to construct a deep neural network (DNN) model trained to reproduce a full set ...
• #### Majorant series for the N-body problem ﻿

(2021-01-01)
As a follow-up of a previous work of the authors, this work considers uniform global time-renormalization functions for the gravitationalN-body problem. It improves on the estimates of the radii of convergence obtained ...
• #### Global Time-Renormalization of the Gravitational N-body Problem ﻿

(2021-01-01)
This work considers the gravitational N-body problem and introduces global time-renormalization functions that allow the efficient numerical integration with fixed time-steps. First, a lower bound of the radius of convergence ...
• #### 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 ...
• #### Approximations for traveltime, slope, curvature, and geometrical spreading of elastic waves in layered transversely isotropic media ﻿

(2021-10)
Each seismic body wave, including quasi compressional, shear, and converted wave modes, carries useful subsurface information. For processing, imaging, amplitude analysis, and forward modeling of each wave mode, we need ...
• #### Vibration-Based SHM Strategy for a Real Time Alert System with Damage Location and Quantification ﻿

(2021-01)
We present a simple and fully automatable vibration-based Structural Health Monitoring (SHM) alert system. The proposed method consists in applying an Automated Frequency Domain Decomposition (AFDD) algorithm to obtain the ...
• #### Error Control and Loss Functions for the Deep Learning Inversion of Borehole Resistivity Measurements ﻿

(2020-05)
Deep learning (DL) is a numerical method that approximates functions. Recently, its use has become attractive for the simulation and inversion of multiple problems in computational mechanics, including the inversion of ...
• #### 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 ...
• #### Vibration-Based SHM Strategy for a Real Time Alert System with Damage Location and Quantification ﻿

(2021-01-11)
We present a simple and fully automatable vibration-based Structural Health Monitoring (SHM) alert system. The proposed method consists in applying an Automated Frequency Domain Decomposition (AFDD) algorithm to obtain the ...
• #### Deep learning driven self-adaptive hp finite element method ﻿

(2021-06)
The fi nite element method (FEM) is a popular tool for solving engineering problems governed by Partial Di fferential Equations (PDEs). The accuracy of the numerical solution depends on the quality of the computational ...
• #### Large-offset P-wave traveltime in layered transversely isotropic media ﻿

(2021-05-01)
Large-offset seismic data processing, imaging, and velocity estimation require an accurate traveltime approximation over a wide range of offsets. In layered transversely isotropic media with a vertical symmetry axis, the ...
• #### On isoptics and isochordal-viewed curves ﻿

(2021)
In this paper, some results involving isoptic curves and constant $\phi$-width curves are given for any closed curve. The non-convex case, as well as non-simple shapes with or without cusps are considered. Relating the ...
• #### Massive Database Generation for 2.5D Borehole Electromagnetic Measurements using Refined Isogeometric Analysis ﻿

(2021-06)
Borehole resistivity measurements are routinely inverted in real-time during geosteering operations. The inversion process can be efficiently performed with the help of advanced artificial intelligence algorithms such as ...
• #### Geometry and tool motion planning for curvature adapted CNC machining ﻿

(2021)
CNC machining is the leading subtractive manufacturing technology. Although it is in use since decades, it is far from fully solved and still a rich source for challenging problems in geometric computing. We demonstrate ...
• #### 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 ...
• #### 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, ...