A novel approach to the model appraisal and resolution analysis of regularized geophysical inversion

Geophysics ◽  
2006 ◽  
Vol 71 (6) ◽  
pp. R79-R90 ◽  
Author(s):  
Michael S. Zhdanov ◽  
Ekaterina Tolstaya
Keyword(s):  
Decomposition Method ◽  
Numerical Technique ◽  
Upper Bounds ◽  
Covariance Matrices ◽  
Cauchy Inequality ◽  
Model Resolution ◽  
Geophysical Inversion ◽  
Bay Area ◽  
Novel Approach ◽  
Resolution Analysis

The existing techniques for appraisal of geophysical inverse images are based on calculating the model resolution and the model covariance matrices. In some applications, however, it becomes desirable to evaluate the upper bounds of the variations in the solution of the inverse problem. It is possible to use the Cauchy inequality for the regularized least-squares inversion to quantify the ability of an experiment to discriminate between two similar models in the presence of noise in the data. We present a new method for resolution analysis based on evaluating the spatial distribution of the upper bounds of the model variations and introduce a new characteristic of geophysical inversion, resolution density, as an inverse of these upper bounds. We derive an efficient numerical technique to compute the resolution density based on the spectral Lanczos decomposition method (SLDM). The methodology was tested on 3D synthetic linear and nonlinear electromagnetic (EM) data inversions, and also to interpret the helicopter-borne EM data collected by INCO Exploration in the Voisey’s Bay area of Canada.

scholarly journals A novel approach to optimize the production cost of railway coaches of India using situational-based composite triangular and trapezoidal fuzzy LPP models

2021 ◽  
Author(s):  
Rakesh Kumar ◽  
Gaurav Dhiman ◽  
Neeraj Kumar ◽  
Rajesh Kumar Chandrawat ◽  
Varun Joshi ◽  
...  
Keyword(s):  
Comparative Study ◽  
Real Time ◽  
Production Cost ◽  
Upper Bounds ◽  
Production Costs ◽  
Cost Data ◽  
Novel Approach ◽  
Membership Grade ◽  
Minimum Costs

AbstractThis article offers a comparative study of maximizing and modelling production costs by means of composite triangular fuzzy and trapezoidal FLPP. It also outlines five different scenarios of instability and has developed realistic models to minimize production costs. Herein, the first attempt is made to examine the credibility of optimized cost via two different composite FLP models, and the results were compared with its extension, i.e., the trapezoidal FLP model. To validate the models with real-time phenomena, the Production cost data of Rail Coach Factory (RCF) Kapurthala has been taken. The lower, static, and upper bounds have been computed for each situation, and then systems of optimized FLP are constructed. The credibility of each model of composite-triangular and trapezoidal FLP concerning all situations has been obtained, and using this membership grade, the minimum and the greatest minimum costs have been illustrated. The performance of each composite-triangular FLP model was compared to trapezoidal FLP models, and the intense effects of trapezoidal on composite fuzzy LPP models are investigated.

scholarly journals Multilingual Projection for Parsing Truly Low-Resource Languages

2016 ◽  
Vol 4 ◽  
pp. 301-312 ◽  
Author(s):  
Željko Agić ◽  
Anders Johannsen ◽  
Barbara Plank ◽  
Héctor Martínez Alonso ◽  
Natalie Schluter ◽  
...  
Keyword(s):  
Empirical Evaluation ◽  
Upper Bounds ◽  
Low Resource ◽  
Part Of Speech Tagging ◽  
Part Of Speech ◽  
Novel Approach ◽  
Cross Lingual ◽  
Test Languages ◽  
Speech Tagging ◽  
Parallel Texts

We propose a novel approach to cross-lingual part-of-speech tagging and dependency parsing for truly low-resource languages. Our annotation projection-based approach yields tagging and parsing models for over 100 languages. All that is needed are freely available parallel texts, and taggers and parsers for resource-rich languages. The empirical evaluation across 30 test languages shows that our method consistently provides top-level accuracies, close to established upper bounds, and outperforms several competitive baselines.

A Novel Approach to Detect Note Onset Using Musical Wavelet

2014 ◽  
Vol 651-653 ◽  
pp. 2094-2098
Author(s):  
Wen Ming Gui ◽  
Yu Feng Chen ◽  
Rui Fan Liu
Keyword(s):  
Feature Extraction ◽  
Decomposition Method ◽  
Experimental Results ◽  
Signal Decomposition ◽  
Onset Detection ◽  
Musical Note ◽  
Frequency Structure ◽  
Novel Approach ◽  
Extraction Stage

In this paper, a novel approach to detect note onset was proposed. At the signal transform stage of the note onset detection, a new musical signal decomposition method based on musical wavelet was bring forward according to the frequency structure of the musical note. At the feature extraction stage, the partial flux feature was proposed in light of the point that some of the partials must change at the time of the onsets. The experimental results indicted that the proposed approach was theoretically feasible and practically effective.

scholarly journals Some Comparison of Solutions by Different Numerical Techniques on Mathematical Biology Problem

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Susmita Paul ◽  
Sankar Prasad Mondal ◽  
Paritosh Bhattacharya ◽  
Kripasindhu Chaudhuri
Keyword(s):  
Mathematical Biology ◽  
Decomposition Method ◽  
Numerical Technique ◽  
Adomian Decomposition Method ◽  
Nonlinear Ordinary Differential Equation ◽  
Volterra Model ◽  
Numerical Techniques ◽  
Numerical Examples ◽  
Adomian Decomposition ◽  
Ordinary Differential Equation Systems

We try to compare the solutions by some numerical techniques when we apply the methods on some mathematical biology problems. The Runge-Kutta-Fehlberg (RKF) method is a promising method to give an approximate solution of nonlinear ordinary differential equation systems, such as a model for insect population, one-species Lotka-Volterra model. The technique is described and illustrated by numerical examples. We modify the population models by taking the Holling type III functional response and intraspecific competition term and hence we solve it by this numerical technique and show that RKF method gives good results. We try to compare this method with the Laplace Adomian Decomposition Method (LADM) and with the exact solutions.

Propagation of Lamb Waves in a Pre-Stressed Plate

2011 ◽  
Vol 66-68 ◽  
pp. 413-418 ◽  
Author(s):  
Jie Liu ◽  
Jin Xiong Zhou
Keyword(s):  
Surface Wave ◽  
Dispersion Relation ◽  
Closed Form ◽  
Lamb Wave ◽  
Decomposition Method ◽  
Lamb Waves ◽  
Finite Thickness ◽  
Helmholtz Decomposition ◽  
Mechanical Behaviors ◽  
Novel Approach

A novel approach is presented to solve the propagation of Lamb wave in a pre-stressed plate with finite thickness, where the commonly used Helmholtz decomposition method fails to find the solution. By using the proposed approach, some important relations of Lamb wave such as the dispersion relation can be obtained and analyzed in closed form, and the effects of initial stress are discussed in details. The method presented herein can be developed further to study the mechanical behaviors of other surface wave acoustic devices.

Modal Identification of damped vibrating systems by iterative smooth orthogonal decomposition method

2020 ◽  
pp. 136943322096844
Author(s):  
Zhixaing Hu ◽  
Jun Li ◽  
Lunhai Zhi ◽  
Xiao Huang
Keyword(s):  
Decomposition Method ◽  
Experimental Studies ◽  
Covariance Matrices ◽  
Transformation Matrix ◽  
Orthogonal Decomposition ◽  
Modal Identification ◽  
Iteration Step ◽  
Coupled Modes ◽  
Smooth Orthogonal Decomposition ◽  
Vibrating Systems

The smooth orthogonal decomposition method (SOD) is an efficient algorithm that can be used to extract modal matrix and frequencies of lightly damped vibrating systems. It uses the covariance matrices of output-only displacement and velocity responses to form a generalized eigenvalues problem (EVP). The mode shape vectors are estimated by the eigenvectors of the EVP. It is stated in this work that the accuracy of the SOD method is mainly affected by the correlation characteristic of modal coordinate responses. For the damped vibration systems, biases will be contained in the results of using the SOD. Therefore, an iterative smooth orthogonal decomposition (ISOD) method is proposed to identify modal parameters of the damped system from the covariance matrices of the displacement, velocity, and acceleration responses. The modal matrix given by the SOD method is updated in each iteration step using a transformation matrix. The transformation matrix can be efficiently computed using a set of analytical formulations. Meanwhile, natural frequencies and damping ratios are obtained by using a simple search method. The performance of the proposed ISOD method is verified by numerical and experimental studies. The results demonstrate that, by considering the correlation of modal responses, the ISOD method can be used to extract accurately the modal information of vibration systems with coupled modes.

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