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Expert has focused on minimizing the current needed to yield lift/stabilization forces with high speed magnetic bearings. He uses boundary element field analyses to perform this optimization as well as to get leakage and eddy current losses. He is developing a passive bearing using null-flux coils.

Expert finds boundary element modeling an excellent technique for accurately modeling electric and magnetic fields. He is capable of extremely accurate predictions of global quantities such as force, torque, inductance, and capacitance. Using boundary element modeling, Expert has been able to analyze literally hundreds of configurations in short order.

Nearly all of Expert's career has centered on the use of numerical modeling systems. A good numerical model can save endless hours in the laboratory or machine shop. Much of his modeling is now performed using MATLAB. At Georgia Tech he teaches a graduate course which focuses on partial differential equations, eigenvalue analyses, optimization and neural net techniques.

Expert has specialized in an area of electromagnetics known as quasistatics, where the displacement current is negligible. His doctorate was in continuum electromechanics - the science of how fields and fluids interact with matter. This area includes eddy currents, electromechanics, electroosmosis, plasma dynamics, and field-fluid pumping.

The operation of many electromechanical devices is summarized by knowing the mutual coupling of coils in various positions. The ability to determine how inductance changes is also essential to many magnetic based sensors. Expert has performed hundreds of analyses on electromechanical devices using inductive coupling.

Expert has centered the last twelve years of his career largely on problems where currents are induced by changing magnetic fields. These applications have ranged from non-destructive evaluation, to sensing, fusion, nerve stimulation, new computational techniques, and stable levitation.

Sensitive electrical impedance measurements can be performed to predict the composition of the interior of the body. Expert is working on techniques to solve the 'inverse problem' associated with such applications.

Having a background in both electrical field theory and fluid mechanics allows Expert to analyze how fields can be used to manipulate fluids. Examples include the shaping of fluids (e.g. with contact lens, menisci) and passive levitation using a conducting fluid in a time-varying magnetic field.

Expert notes that stable magnetic levitation can be realized effectively by using eddy current forces which come as a result of passive induction. By using null-flux coils, stable levitation both for rotary and linear applications can be produced. The same levitation effects are useful in metal molding and fabrication. Expert has two patents pending in the field of magnetic levitation.

Non-invasive nerve stimulation is effectively produced using rapidly-changing magnetic fields. The changing magnetic field induces an electric field causing charge transfer to occur across the nerve membrane interface causing the nerve to fire. The source of the field can be either external or internal to the body. Expert has constructed successful stimulators (in vitro and in vivo) and has written several papers on these devices.

Metals are conventionally separated by a number of methods, one of which uses eddy currents. Systems utilizing eddy currents have traditionally been constructed using magnets which are mounted on a rotating drum which is positioned under a conveyor belt on which the material rests. Geometrical variations from the conventional arrangements of the magnets can significantly enhance the separation forces. Eddy current forces using variants of these principles can be used to realize metal-metal separation. Expert is currently involved in this area.

A large amount of Expert's work has focused on electrodynamic suspensions in which the currents are induced in the secondary member to yield lift and guidance forces. The primary directive in most maglev research is to reduce the system cost. Expert achieves this by using a track-based coil in a multiplicity of functions.

A target goal in many applications is to design a magnet to deliver a specified B field, force, or torque for the minimum weight or cost. By using parametric techniques, Expert has been able to model up to four variable optimizations using a mixed order polynomial. This polynomial is smoothly differentiable and lends itself to contained sequential quadratic programming approaches.

MAGNETIC OPTIMIZATION. Expert has been using optimization techniques such as sequential quadrative programming to shape field structures. Applications include (a) Designing magnetic structures to target an average field desired with a minimum weight; (b) Designing coils in a levitation device for the least cost; (c) Generating a given motor torque for the smallest volume.

Each of these applications involves a parametric field analysis, modeling the system in terms of a smoothly differentiable function before calling on the optimization algorithm.