Searched for: subject:"inverse%5C+problem"
(1 - 20 of 45)

Pages

document
Flaschel, Moritz (author), Kumar, Siddhant (author), De Lorenzis, Laura (author)
We propose a new approach for data-driven automated discovery of isotropic hyperelastic constitutive laws. The approach is unsupervised, i.e., it requires no stress data but only displacement and global force data, which are realistically available through mechanical testing and digital image correlation techniques; it delivers interpretable...
journal article 2021
document
Fuchs, P.S. (author)
Electrical properties, the conductivity and permittivity of tissue, are quantities that describe the interaction of an object and electromagnetic fields. These properties influence electromagnetic fields and are influenced themselves by physiological phe- nomena such as lesions or a stroke. Therefore, they are important in identifying or...
doctoral thesis 2020
document
van Rooij, J. (author)
Optical imaging is the imaging of objects with visible light. It is a tool often used for diagnostic purposes, such as in biomedical and material sciences. Digital holography is an optical imaging technique that captures and images the amplitude as well as the phase (the complex amplitude) of the lightwave. An advantage is that the complex...
doctoral thesis 2020
document
Jongbloed, G. (author), Mc Garrity, K.S. (author), Sietsma, J. (author)
Kernel estimators are proposed for estimating the cumulative distribution functions and the probability density functions of several quantities of interest in a stereological oriented cylinder model. This oriented cylinder model was developed to represent anisotropic microstructural features in materials. The asymptotic properties of these...
journal article 2020
document
Shachor, Benny (author)
Understanding the permeability of the subsurface is a crucial step to simulate fluid flow in the subsurface. A parameter estimation problem for the flow equations can be solved to find the permeability. The robust identification of material parameters remains a significant challenge. In classical approaches, the non-linear least-squares problem...
master thesis 2019
document
van den Brink, Robbert-Jan (author)
Mines and improvised explosive devices are the cause of many mortalities of vehicle occupants. Both experimental and numerical research in this field aims to improve the safety of military vehicles. TNO has advanced Finite Element (FE) models to simulate such events. The numerical research is done to better understand mine blasts. Another aim is...
master thesis 2019
document
Nickl, Richard (author), Söhl, J. (author)
We study nonparametric Bayesian statistical inference for the parameters governing a pure jump process of the form (Formula Presented) where N(t) is a standard Poisson process of intensity λ, and Z <sub>k</sub> are drawn i.i.d. from jump measure μ. A high-dimensional wavelet series prior for the Lévy measure ν = λμ is devised and the...
journal article 2019
document
Abdi, Bahareh (author), Hendriks, R.C. (author), van der Veen, A.J. (author), de Groot, Natasja M.S. (author)
Finding the hidden parameters of the cardiac electrophysiological model would help to gain more insight on the mechanisms underlying atrial fibrillation, and subsequently, facilitate the diagnosis and treatment of the disease in later stages. In this work, we aim to estimate tissue conductivity from recorded electrograms as an indication of...
journal article 2019
document
Sun, S. (author), Kooij, B.J. (author), Yarovoy, Alexander (author)
In this paper, the generalized multiple measurement vectors (GMMV) linear inversion method is applied to the reconstruction of the 3-D Fresnel data, provided by the Institue Fresnel (Marseille, France). The results show that the GMMV-based method can obtain good resolution along the x- and y- axes, while poor resolution along the z-axis,...
conference paper 2019
document
Naghibzadeh, S. (author)
Fundamental scientific questions such as how the first stars were formed or how the universe came into existence and evolved to its present state drive us to observe weak radio signals impinging on the earth from the early days of the universe. During the last century, radio astronomy has been vastly advancing. Important discoveries on the...
doctoral thesis 2018
document
Thota Radhakrishnan, A.K. (author), van Lier, J.B. (author), Clemens, F.H.L.R. (author)
Information on the rheology of domestic slurries is essential in designing pipeline transportation in novel sanitation systems. As concentrated slurries in their original collected state have wide particle size distribution, with particles up to 2 mm, a wide gap rheometer is used to acquire the rheograms. Rheograms obtained from a wide gap...
journal article 2018
document
Schaaphok, Marianne (author)
This research presents a data-driven model for the magnetic signature of an object, consisting of linearly reacting isotropicmaterial. From magnetostatics mathematical-physical model is derived for the linear behaviour of the induced magnetization. Data-driven updates for the permanent magnetization are computed from comparisons of the computed...
bachelor thesis 2018
document
Schwarz, Alexander (author), Dwight, R.P. (author)
We investigate theoretically and numerically the use of the least-squares finite-element method (LSFEM) to approach data-assimilation problems for the steady-state, incompressible Navier-Stokes equations. Our LSFEM discretization is based on a stress-velocity-pressure (S-V-P) first-order formulation, using discrete counterparts of the Sobolev...
journal article 2018
document
Konijnenberg, A.P. (author), Coene, W.M.J.M. (author), Urbach, Paul (author)
A noise-robust extension of iterative phase retrieval algorithms that does not need to assume a noise model is proposed. It works by adapting the intensity constraints using the reconstructed object. Using a proof-of-principle ptychographic experiment with visible light and a spatial light modulator to create an object, the proposed method is...
journal article 2018
document
D' Onofrio, Federica (author)
RANS equations are nowadays widely used in industry because of their affordability in terms of computational costs. They reached a high level of complexity, as they involve systems of non-linear partial differential equations. However they still lack of generality as they are based on closure coefficients determined from fundamental real flow...
master thesis 2017
document
Lopatin, Craig (author), Rabinovich, Daniel (author), Givoli, D. (author), Turkel, Eli (author)
A model-based non destructive testing (NDT) method is proposed for damage identification in elastic structures, incorporating computational time reversal (TR) analysis. Identification is performed by advancing elastic wave signals, measured at discrete sensor locations, backward in time. In contrast to a previous study, which was purely...
journal article 2017
document
Belligoli, Z. (author), Dwight, R.P. (author), Kok, G. J.P. (author), Lucas, P. (author)
This paper presents an approach for updating the epistemic uncertainty of ultrasonic flow meter measurements under non-ideal flow conditions. Instead of re-calibrating the instrument to correct its behavior in these difficult working conditions, a Bayesian calibration of a computer model of the real process is used. The numerical model is...
journal article 2017
document
Trull, A.K. (author), van der Horst, J. (author), Palenstijn, W.J. (author), van Vliet, L.J. (author), van Leeuwen, Tristan (author), Kalkman, J. (author)
As a result of the shallow depth of focus of the optical imaging system, the use of standard filtered back projection in optical projection tomography causes space-variant tangential blurring that increases with the distance to the rotation axis. We present a novel optical tomographic image reconstruction technique that incorporates the point...
journal article 2017
document
Ishiyama, T. (author), Blacquière, G. (author), Verschuur, D.J. (author), Mulder, W.A. (author)
Surface waves in seismic data are often dominant in a land or shallow-water environment. Separating them from primaries is of great importance either for removing them as noise for reservoir imaging and characterization or for extracting them as signal for near-surface characterization. However, their complex properties make the surface-wave...
journal article 2016
document
Kahrobaei, S.S. (author)
doctoral thesis 2016
Searched for: subject:"inverse%5C+problem"
(1 - 20 of 45)

Pages