Now showing items 1-20 of 70

• #### 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 ...
• #### 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, ...
• #### 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 ...
• #### 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 ...
• #### Arithmetic method of double-injection-electrode model for resistivity measurement through metal casing ﻿

(2010-12-31)
Through-casing resistivity (TCR) measurement instruments such as Cased Hole Formation Resistivity are extensively used for the dynamic monitoring of oil reservoirs during the production phase in oil wells to evaluate the ...
• #### Asymptotic Models for the Electric Potential across a Highly Conductive Casing ﻿

(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 ...
• #### Automatic Red-Channel underwater image restoration ﻿

(2015-12-31)
Underwater images typically exhibit color distortion and low contrast as a result of the exponential decay that light suffers as it travels. Moreover, colors associated to different wavelengths have different attenuation ...
• #### Bearing assessment tool for longitudinal bridge performance ﻿

(2020-09)
This work provides an unsupervised learning approach based on a single-valued performance indicator to monitor the global behavior of critical components in a viaduct, such as bearings. We propose an outlier detection ...
• #### Borehole Resistivity Simulations of Oil-Water Transition Zones with a 1.5D Numerical Solver ﻿

(2020)
When simulating borehole resistivity measurements in a reservoir, it is common to consider an oilwater contact (OWC) planar interface. However, this consideration can lead to an unrealistic model since in the presence of ...
• #### Compensation effect analysis in DIE method for through-casing measuring formation resistivity ﻿

(2011-08)
The measuring technique based on Double-Injection-Electrodes (DIE) and its compensation arithmetic method have been proven to be very useful for eliminating the errors caused by electrode-scale mechanical tolerances in ...
• #### Computational cost estimates for parallel shared memory isogeometric multi-frontal solvers ﻿

(2014-12-31)
• #### A DPG-based time-marching scheme for linear hyperbolic problems ﻿

(2020-11)
The Discontinuous Petrov-Galerkin (DPG) method is a widely employed discretization method for Partial Di fferential Equations (PDEs). In a recent work, we applied the DPG method with optimal test functions for the time ...
• #### Energy-norm-based and goal-oriented automatic hp adaptivity for electromagnetics: Application to waveguide Discontinuities ﻿

(2008-12-31)
The finite-element method (FEM) enables the use of adapted meshes. The simultaneous combination of h (local variations in element size) and p (local variations in the polynomial order of approximation) refinements, i.e., ...
• #### Enhanced variational image dehazing ﻿

(2015-12-31)
Images obtained under adverse weather conditions, such as haze or fog, typically exhibit low contrast and faded colors, which may severely limit the visibility within the scene. Unveiling the image structure under the haze ...