Intro (fwd)

Guy Laden (laden@math.tau.ac.il)
Mon, 22 Apr 1996 23:12:16 +0300 (GMT+0300)

I realized to my horror that the welcome message didnt include
the address for posting to the mailing list!
It is: oberonf@math.tau.ac.il

Below is a message meant for the list which was sent to me
personally because of my oversight.

Guy.

--

Forwarded message: >From al@sarah.lerc.nasa.gov Mon Apr 22 15:18:12 1996 Date: Mon, 22 Apr 1996 08:14:56 -0400 (EDT) Subject: Re: a posting to: Oberon/F mailing list

Hello,

>It'd be nice if you sent an 'intro' to the list describing what you do >and how you use the framework (ofcourse this is completly optional).

I'm Al Freed, a materials research engineer for NASA. My job description is to develop, characterize, implement and verify materials models for their deformation response under the adverse conditions of jet and rocket engines and, more recently, the processing of materials. Why tell you this? I've been a FORTRAN programmer until Oberon-2 came along. Forget C or C++, they just don't make sense to me. I guess I'm left-lobe brain dominant and you need to be a right-lober to understand it, or something like that. Oberon-2 was the language I was looking for - introduced to me on a trip to Europe I made some 5 years ago.

I've used V2, V4 and System 3, but when Oberon/F came out I changed to it. I now use only Oberon/F, not that I didn't enjoy the others. Oberon/F being a commercial product has a vested interest in the future. That was my first reason for changing over. I like their environment so much I'll not change back. For the record, I run Oberon/F on Windoze NT 3.51.

I developed a module for numerical integration of first-order, ordinary, differential equations called ODE. At present it is in vs 1.02 and is available from Bob Brown's web cite http://www.dstc.edu.au/BDU/staff/bob/Oberon/OberonArch.html The next upgrade will permit ODE to run nicely as a background process. I'm in the process of installing multiple Actions, see Obx examples, into the module. If nothing else, ODE serves as a clear demonstration that Oberon-2 is a viable language for numerical computation (number crunching) and, believe me, Oberon/F makes the debugging process a breeze compared to other languages one typically associates with for this purpose.

Future work: I'm writing an optimizer to attach to ODE (mostlikely it will become part of this same module) whose objective will be to obtain best fits of model (ODEs) constants to data supplied by the user. For example, say you are a chemist (or are working with one) and you have a chemical reaction whose mathematical sturture (a system of stiff ODEs) you know but whose model (material) constants are unknown. How do you get them? Run experiments and compare (trial and error) model predictions to data, or, do the inverse problem and let an optimizer do the job for you. Anyway, that is one of my projects.

The other has to do with graphical display. Take the optimizer mentioned above. I want a visual picture of input data vs. predicted response as an XY plot. Here I'm outside my field of expertise, so this is a learn as you go project, and learn I have. Attaining this objective is a goal set for at least a year or more into the future. Since this is not a NASA project, I would be interested in collaborating with anyone who has like interests. This could become a commerical product - time and talent permitting.

I expect many good things to come from this mailing list. Thanks Guy for putting it together for us.

Best wishes to all readers,

\|/ (o o) +=================oOOo==\_/==oOOo=================+ | Alan D. Freed, Ph.D. | | Computational Materials Laboratory, MS 105-1 | | NASA Lewis Research Center | | 21000 Brookpark Road | | Cleveland, OH 44135-3191 | | | | tel: 1-216-433-8747 | | fax: 1-216-433-5033 | | email: afreed@lerc.nasa.gov | | al@sarah.lerc.nasa.gov | | web: http://sarah.lerc.nasa.gov/~al | | | | The views expressed are my own. They are not | | necessarily those of NASA or the US Government. | +-------------------------------------------------+