Estimating uncertainty in inverse elasticity with application to quantitative elastography

2011 ◽  
Vol 130 (4) ◽  
pp. 2405-2405
Author(s):  
Paul E. Barbone ◽  
Bryan Chue ◽  
Assad A. Oberai
Keyword(s):  
Inverse Elasticity

scholarly journals Adjoint-weighted variational formulation for the direct solution of plane stress inverse elasticity problems

2008 ◽  
Vol 135 ◽  
pp. 012012 ◽  
Author(s):  
Paul E Barbone ◽  
Carlos E Rivas ◽  
Isaac Harari ◽  
Uri Albocher ◽  
Assad A Oberai ◽  
...  
Keyword(s):  
Plane Stress ◽  
Variational Formulation ◽  
Direct Solution ◽  
Elasticity Problems ◽  
Inverse Elasticity

A Stabilized B-Splines FEM Formulation for the Solution of an Inverse Elasticity Problem Arising in Medical Imaging

2008 ◽  
Author(s):  
Carlos E. Rivas ◽  
Paul E. Barbone ◽  
Assad A. Oberai
Keyword(s):  
Mechanical Properties ◽  
Diagnostic Value ◽  
Incompressible Material ◽  
High Order ◽  
Elasticity Problem ◽  
Parameter Distribution ◽  
Order Continuity ◽  
B Splines ◽  
Inverse Elasticity ◽  
Continuous Problem

Soft tissue pathologies are often associated with changes in mechanical properties. For example, breast and other tumors usually present as stiff lumps. Imaging the spatial distribution of the mechanical properties of tissues thus reveals information of diagnostic value. Doing so, however, typically requires the solution of an inverse elasticity problem. In this work we consider the inverse elasticity problem for an incompressible material in plane stress, formulated and solved as a constrained optimization problem. We formulate this inverse problem enforcing high order continuity for our variables. Driven by the requirements for the strong and weak solutions to this problem, we assume that our data field (i.e. the measured displacement) is in H2 and our parameter distribution (i.e. the sought shear modulus distribution) is in H1. This high order regularity requirement for the data is incompatible with standard FEM. We solve this problem using a FEM formulation that is novel in two respects. First, we employ quadratic b-splines that enforce C1 continuity in our displacement field, consistent with the variational requirements of the continuous problem. Second, we include Galerkin-least-squares (GLS) stabilization in the iterative optimization formulation. GLS adds consistent stability to the discrete formulation that otherwise violates an ellipticity condition that is satisfied by the continuous problem. Computational examples validate this formulation and demonstrate numerical convergence with mesh refinement.

scholarly journals Quantitative Compression Optical Coherence Elastography as an Inverse Elasticity Problem

2016 ◽  
Vol 22 (3) ◽  
pp. 277-287 ◽  
Author(s):  
Li Dong ◽  
Philip Wijesinghe ◽  
James T. Dantuono ◽  
David D. Sampson ◽  
Peter R. T. Munro ◽  
...  
Keyword(s):  
Elasticity Problem ◽  
Optical Coherence ◽  
Inverse Elasticity

scholarly journals The Evaluation of Asymmetry in Price Transmission and Market Power in Iran Sugar Production Industry

2016 ◽  
Vol 8 (11) ◽  
pp. 127
Author(s):  
Mohammad Omrani ◽  
Mohammad Nabi Shahiki Tash ◽  
Ahmad Akbari
Keyword(s):  
Market Power ◽  
Agricultural Products ◽  
Price Transmission ◽  
Sugar Production ◽  
Asymmetric Price Transmission ◽  
Inverse Elasticity ◽  
Production Industry ◽  
Seasonal Data

<p>Asymmetric price transmission in production institutes can be a reason for the existence of market power. In this regard, by the help of an integrative sample, this study simultaneously analyzes the price transmission between production markets and retails markets of sugar in the presence of the parameter of market power. For this purpose, the seasonal data of the required variables during the years 1995-2013 was used. In order to meet the study objectives, the behavior of the retails price of sugar was evaluated in the framework of two regimes of different changes which were compatible with nature of presenting agricultural products that are widely supplied in the harvest seasons. Also, the inverse elasticity of product supply was used as the parameter of market power. Considering the more probable regime (second regime), it was realized that the marketing elements at the wholesale level intend to price transmission increase more intensively than price decrease to the retail trades level. In this regime, asymmetric price transmission and existence of market power were approved. In the first regime, market power was much more and considering the fact that it has the 30% probability of happening, it has more compatibility with the seasons when supply is abundant. In these seasons, sugar production and refining units increase the market power and create a monopsony market in buying the inputs.</p>

Quantitative optical coherence elastography as an inverse elasticity problem (Conference Presentation)

2016 ◽  
Author(s):  
Li Dong ◽  
Philip Wijesinghe ◽  
James T. Dantuono ◽  
David D. Sampson ◽  
Peter R. T. Munro ◽  
...  
Keyword(s):  
Elasticity Problem ◽  
Optical Coherence ◽  
Inverse Elasticity
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