Jamshid Ghaboussi

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A new representation combining redundancy and implicit fitness constraints is introduced that performs better than a simple genetic algorithm (GA) and a structured GA in experiments. The implicit redundant representation (IRR) consists of a string that is over-specified, allowing for sections of the string to remain inactive during function evaluation. The(More)
Intraocular pressure (IOP) in the human eye as measured by a Goldmann applanation tonometer (GAT) is known to be affected by individual differences in central corneal thickness (CCT). However, data from clinical studies also show considerable scatter in the correlation between measured IOP and CCT. One possible implication of the large observed scatter is(More)
This paper presents findings of a railroad ballast Discrete Element Modeling (DEM) research study focused on investigating ballast settlement under repeated wheel loading. In this approach, the ballast layer is modeled as an assembly of aggregate particles, AREMA No. 24 ballast gradation with different shapes and angularities and rough surface textures. The(More)
This paper presents an improved self-learning simulation and its application to modeling of ‘cyclic’ behavior of the connections from the results of structural testing. Unlike other inverse modeling approaches such as parameter optimization methods, the proposed method requires no prior knowledge about the behavior and model. It can extract the cyclic(More)
PURPOSE To demonstrate the importance of material properties of the cornea in intraocular pressure (IOP) readings via standard Goldmann applanation tonometry. METHODS A realistic finite element model of the cornea was developed for the simulation of Goldmann applanation tonometry. A virtual cornea population was generated by randomly sampling material(More)
The fact that Goldmann applanation tonometry does not accurately account for individual corneal elastic stiffness often leads to inaccuracy in the measurement of intraocular pressure (IOP). IOP should account not only for the effect of central corneal thickness (CCT) but should also account for other corneal biomechanical factors. A computational method for(More)
A new control method using Genetic Algorithms (GAs) to reduce the structural response under seismic excitation is proposed. The proposed control method uses state space reconstruction technique to obtain the full state performance from the available reduced order feedback. The controller is optimized using GAs without making simplifying assumptions. The(More)
An information-based technique is described for applications in mechanical property imaging of soft biological media under quasi-static loads. We adapted the Autoprogressive method that was originally developed for civil engineering applications for this purpose. The Autoprogressive method is a computational technique that combines knowledge of object shape(More)
Ballast, typically comprising large sized aggregate particles with uniform gradation, is an essential layer in the railroad track substructure. Functions of ballast include facilitating load distribution and drainage, maintaining track geometry and track stability, and providing track resilience and noise absorption. Throughout its service life, ballast(More)