User Portlet

I have had a career making mathematical models of forest dynamics using applied mathematical models -- ordinary nonlinear first order differential equations mostly -- wherein the observations on forests (from permanent sample plots) were taken as boundary conditions governing the differential equation solution. I followed the works of Bellman, Kalaba, Kagiwada, and Childs who developed the quasilinearization method of model parameter estimation, and developed fortran code to implement the method of complimentary functions as well as the perturbed particular solutions method. Early service in US Peace Corps piqued my interest in appropriate technology, so with help of Kevin Nimerfro we developed a Mathematica Demonstration of a parabolic trough solar concentrator -- to be used for roasting groundnuts in Africa -- so we could simulate effects of focus, roasting tube size, concentration factor, etc. With new findings about ice crystal producing more diffuse and less 'beam' radiation, I would like to revisit the solar concentrator work. I've had a long standing interest in research methods instruction for graduate students, and Mathematica has been the ONLY package that can track the loss of significant digits in a long series of computations. Our forest measurement instruments have limited resolution -- most tree stem measurements have at most 3 significant digits. Should one subtract two repeated measurements on the same tree a few years apart, the difference may contain a single significant digit. Mathematica allows one to tract the loss of significance in model parameters on final system predictions -- which can become very 'grainy'. After 9/11 I used Mathematica to outline a teardrop shaped structure for the memorial competition. I passed the output to architect Peter Taylor Ernst, expert in SketchUp, who finalized the design -- still available on the web. I've continued to explore relationships in the nested tear shapes.