نتایج جستجو برای: deterministic inversion

تعداد نتایج: 90490  

ژورنال: ژئوفیزیک ایران 2020
Mahjoobeh Meskaranian Peyman Pour Moghaddam

This study derives the discretized adjoint states full waveform inversion (FWI) in both time and frequency domains based on the Lagrange multiplier method. To achieve this, we applied adjoint state inversion on the discretized wave equation in both time domain and frequency domain. Besides, in this article, we introduce reliability tests to show that the inversion is performing as it should be ...

Journal: :Computers & Geosciences 2021

Inversion of electromagnetic data finds applications in many areas geophysics. The inverse problem is commonly solved with either deterministic optimization methods (such as the nonlinear conjugate gradient or Gauss-Newton) which are prone to getting trapped a local minimum, probabilistic very computationally demanding. A recently emerging alternative employ deep neural networks for predicting ...

Gravity data inversion is one of the important steps in the interpretation of practical gravity data. The inversion result can be obtained by minimization of the Tikhonov objective function. The determination of an optimal regularization parameter is highly important in the gravity data inversion. In this work, an attempt was made to use the active constrain balancing (ACB) method to select the...

Remnant magnetization causes a change in the direction and intensity of the magnetization vector. If inversion is performed regardless of remnance, in some cases it may have unreliable and misleading results. For inversion with respect to remnant magnetization, several solutions have been proposed so far, one of which is to convert the data of total magnetic field into data that is independent ...

Shear-wave velocity ( ) is an important parameter used for site characterization in geotechnical engineering. However, dispersion curve inversion is challenging for most inversion methods due to its high non-linearity and mix-determined trait. In order to overcome these problems, in this study, a joint inversion strategy is proposed based on the particle swarm optimization (PSO) algorithm. The ...

2012
Shengji Wei Robert Graves Don Helmberger Jean-Philippe Avouac Junle Jiang

Oki earthquake. Here we combine deterministic inversion and dynamically guided forward simulation methods to model over one thousand high-rate GPS and strong motion observations from 0 to 0.25 Hz across the entire Honshu Island. Our results display distinct styles of rupture with a deeper generic interplate event ( Mw8.5) transitioning to a shallow tsunamigenic earthquake ( Mw9.0) at about 25 k...

2014
Daniel Kostrzewa

The expanded Invasive Weed Optimization algorithm (exIWO) is an optimization metaheuristic modelled on the original IWO version created by the researchers from the University of Tehran. The authors of the present paper have extended the exIWO algorithm introducing a set of both deterministic and nondeterministic strategies of individuals’ selection. The goal of the project was to evaluate the e...

2006
Christian Weihrauch Ivan Tomov Dimov Simon Branford Vassil N. Alexandrov

In this paper we consider bilinear forms of matrix polynomials and show that these polynomials can be used to construct solutions for the problems of solving systems of linear algebraic equations, matrix inversion and finding extremal eigenvalues. An almost Optimal Monte Carlo (MAO) algorithm for computing bilinear forms of matrix polynomials is presented. Results for the computational costs of...

2008
Gavin E. Crooks

The dynamics of an open quantum system can be described by a quantum operation: A linear, complete positive map of operators. Here, I exhibit a compact expression for the time reversal of a quantum operation, which is closely analogous to the time reversal of a classical Markov transition matrix. Since open quantum dynamics are stochastic, and not, in general, deterministic, the time reversal i...

1993
Carsten Peterson

A deterministic algorithm for calculating polymer properties is presented. It is based on a variational approach where the bond and Coulomb potentials are approximated by a quadratic trial energy. The parameters, which describe average atom positions and Gaussian uctuations, are the solutions of matrix equations. By a judicious choice of parameter representations and the use of incremental matr...

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