THE LEVICH INSTITUTE ANNOUNCES THE FOLLOWING SEMINAR:

Tuesday, 12/8/98
4:00 PM
Steinman Hall, Room #1M-22
Professor Salvatore Torquato
Princeton University
Department of Civil Engineering and Operations Research and Princeton Materials Institute
"Reconstructing Random Media: An Intriguing Inverse Problem"


ABSTRACT

The reconstruction of heterogeneous media, such as porous and composite media, from a knowledge of limited morphological information (correlation functions) is an intriguing inverse problem. An effective reconstruction procedure enables one to generate accurate structures at will, and subsequent analysis can be performed on the image to obtain desired macroscopic properties (e.g., transport, electromagnetic and mechanical properties) of the media. This provides a non-destructive means of estimating the macroscopic properties: a problem of important technological relevance. We formulate a procedure to reconstruct the structure of general random media from limited morphological information. The procedure has the advantages that it is simple to implement and generally applicable to multidimensional, multiphase and anisotropic structures. Furthermore, an extremely useful feature is that it can incorporate any type and number of correlation functions in order to provide as much morphological information as is necessary for accurate reconstruction. We have used our algorithm to construct heterogeneous media from specified hypothetical correlation functions as well as physically unrealizable ones. We have also employed use of the algorithm to reconstruct a three-dimensional image of a sandstone by utilizing morphological information extracted from a two-dimensional slice (thin section) of the sandstone. The procedure sheds light on the nature of the information contained in the correlation functions and can aid in classifying random media. It is shown that the structure factor obtained from scattering is usually not sufficient to reconstruct the material accurately.

BRIEF ACADEMIC/EMPLOYMENT HISTORY:

1980        Ph.D., Mechanical Engineering, SUNY, Stony Brook
1982-85   Assistant Professor, Mechanical Engineering, North Carolina State University
1985-91   Associate Professor, North Carolina State University
1991-92   Professor, North Carolina State University
1992-       Professor, Department of Civil Engineering and Operations Research, Princeton University

RESEARCH INTERESTS:

Statistical mechanics, transport and mechanical properties of composite and porous materials, biological materials, percolation theory, image science and cancer growth.


Return to Fall, 1998 Seminar Schedule