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October 28, 1998
QuestChat with Roxana Greenman

Aerospace Engineer
NASA Ames Research Center, Moffett Field, CA

[ Oran/NASAChatHost - 3 - 08:48:52 ]
Hello to our early arriving Aerospace Team Online chat participants! Aerospace Team Online chat with Roxana Greenman from NASA Ames Research Center will begin at 9:00 a.m., Pacific Time. Be sure you have read Roxana's autobiography at http://quest.arc.nasa.gov/aero/team/greenman.html before joining this chat.

[ Oran/NASAChatHost - 4 - 08:49:25 ]
Once the chat begins, Roxana will attempt to answer as many of your questions as she can, but please be patient. The chat will "moderated" if Roxana gets behind in answering your questions. This means that only a few questions will be posted to the chat room at a time. Don't worry if your questions do not appear on your screen immediately. They will be posted as Roxana answers those ahead of you.

[ Oran/NASAChatHost - 5 - 08:49:47 ]
As a reminder, remember to enter "Your Handle" in the box provided, before posting questions to the chat room. Once you've done this, please let us know that you have logged on for today's chat.

[ Oran/NASAChatHost - 6 - 08:50:16 ]
At the conclusion of today's chat, we ask that you take a few minutes to let us know what you thought about it. For your convenience, you may use our online feedback forms at http://quest.arc.nasa.gov/qchats/qchat-surveys. We look forward to hearing from you!

[ Oran/NASAChatHost - 8 - 08:58:16 ]
RE: [Ann/AERO-Ann/AERO] Good morning aspiring and practicing research scientists and Aloha.
Welcome, Ann. We'll begin our chat shortly. Please stay with us!

[ Oran/NASAChatHost - 9 - 08:59:24 ]
Hello and welcome to today's Aerospace Team Online chat with Roxana Greenman from NASA Ames Research Center! Roxana researches the field of computational fluid dynamics (CFD). CFD is the process of using computers to solve complex equations associated with aircraft flight. One of her current research areas is the development of new methods that incorporate information technology into CFD design methods. She is trying to learn the benefits of combining technology based on our biological nervous systems with special computer programs.

[ Oran/NASAChatHost - 10 - 08:59:44 ]
And now, here is Roxana Greenman to answer your questions.

[ RoxanaGreenman/ARC - 14 - 09:08:01 ]
Good Morning! I look forward to answering and chatting with all of today!

[ RoxanaGreenman/ARC - 13 - 09:06:46 ]
RE: [Ann/AERO-Ann/AERO] Would you please describe the high-lift devices which you design and explain how they relate to the human nervous system.
Good Morning Ann! High-lift devices are located on the wing. They consist usually of a slat which is the leading-edge device and a flap which is the trailing-edge device. One of there many purpose is to help the aircraft generate more lift. They are used at takeoff and landing and are stowed during cruise. Now, neural networks are computational devices that model the human nervous system. They are two different items. High-lift devices do NOT model the human nervous system.

[ Oran/NASAChatHost - 18 - 09:15:23 ]
Roxana, perhaps you can share with us any obstacles or constraints you've had to contedn with as you've moved along in your career.

[ RoxanaGreenman/ARC - 20 - 09:18:30 ]
I recently received my doctorate at Stanford University. Researching, writing, and defending my Ph. D. dissertation has been one of the most difficult events that I have accomplished. But at the same time, it was one of the most rewarding!

[ RoxanaGreenman/ARC - 22 - 09:20:54 ]
Recently, I have integrated a genetic algorithm, neural network, and an optimizer together to find the maximum lift of a multi-element wing. The wing had a slat, main, and flap element on it. The genetic algorithm mimics the evolution process of the "survival of the fittest" to find the best answer.

[ RoxanaGreenman/ARC - 24 - 09:23:55 ]
RE: [Shae-Shae/LamarUniversity] You said that working with NASA has alwaays been fun. What kinds of things do you do that make this possible?
Good Morning Shae! I enjoy working at NASA because there are so many opportunities that are available to me. I was able to choose the topic of research that I have been involved in for the last 3 years. This is important to me. Also at NASA, my collegues give me great support and help to succeed. It also rewarding to be working with scientists who are known world-wide and I also enjoy working with all the state-of-the-art equipment.

[ RoxanaGreenman/ARC - 26 - 09:26:13 ]
RE: [Ann/AERO-Ann/AERO] Yes that would be great, also could you refer us to any published info on your research and/or available space science publications. Thank you.
Ann, in my Ph.D. dissertation, I have an excellant Reference list. Here is the reference for my dissertation: Greenman, R. M., "Two-Dimensional High-Lift Aerodynamic Optimization Using Neural Networks, Ph. D. Dissertation, Stanford University (see Also NASA TM 1998-112233), June 1998. If you need more please let me know.

[ RoxanaGreenman/ARC - 28 - 09:29:21 ]
RE: [Shae-Shae/LamarUniversity] I wish to have a career in NASA and so, would love to have an inside view on the kinds of things that are done and the opportunities that will be presented.
First of all, I would highly encourage getting involved with NASA as you are now! This is what I am currently working on: 1) Preparing journal articles 2) Investigating genetic algorithms and other information technology 3) I will participate in the planning of IVHM (Integrated Vehicle health monitoring) 4) I also review proposals and other papers 5) business stuff. But remember that there are many different opportunities with NASA. It really depends on your job and what research group you are in.

[ RoxanaGreenman/ARC - 29 - 09:31:47 ]
RE: [Shae-Shae/LamarUniversity] Do you work with any of the space program? That is the area in which NASA has drawn my attention most.
Currently, I am not involved with the space program. But in the NEAR future I will be. With IVHM we will be looking at space vehicles and my divion is also moving in the direction of space. We will be examining Reuseable Launch Vehicles (RLV). I am very excited about this!!

[ RoxanaGreenman/ARC - 31 - 09:35:02 ]
RE: [Ann/AERO-Ann/AERO] Roxana, I am an adult educator, un-fortunately the school day has not begun yet here (the students are just getting on the bus). Your explanations of complicated research are so clear and easy to understand. On a recent Discovery channel show, it was suggested that space travel and travel to the deep sea are similar. Since you're the ocean is important in your leisure hours, have you observed similarities?
I have also heard about space travel and travel in the deep sea are similar. Unfortunately, I have not done either. So I am not sure.

[ Oran/NASAChatHost - 32 - 09:35:52 ]
As a reminder, at the conclusion of today's chat, please let us know what you thought about it at http://quest.arc.nasa.gov/qchats/qchat-surveys. Thanks!

[ RoxanaGreenman/ARC - 33 - 09:36:09 ]
RE: [Shae-Shae/LamarUniversity] That sounds amazing!
Thanks!! Shae -- what do you study? Aeronautics? Do you like your University?

[ RoxanaGreenman/ARC - 35 - 09:39:54 ]
RE: [Shae-Shae/LamarUniversity] If so, what kinds of things do you do?
I imagine in the future, I will apply computational fluid dynamics (CFD) to the different space vehicles that we will be researching. Also, I will use CFD with information technology such as neural networks, genetic algorithms, and others to try to locate optimums or to enhance our database.

[ RoxanaGreenman/ARC - 37 - 09:43:58 ]
RE: [Shae-Shae/LamarUniversity] I am studying to become an Aerospace engineer. I am not really sure yet about what in particular I would like to do and am presently searching for information.
Good for you! It sounds like you are definitely intesteted in space versus aeronautics. You must be excited about the next launch in the next day or so. Another great source for information on different areas of research are the journals. For example, Journal of Aircraft, AIAA Journal, and Journal of Fluids Engineering. These will have a lot of information on the new topics that are being researched. Sometimes just reading the abstracts will give you a good feel for what is important in industry and govenment.

[ RoxanaGreenman/ARC - 40 - 09:49:20 ]
RE: [Shae-Shae/LamarUniversity] RLV sounds interesting. In what particular ways would you apply CFD to this progect?
CFD can be used in RLV research in many ways. One imporant result from CFD would be the loads that the vehicle would experience during its flight and especially in re-entery. In this case, we will have to incorporate chemistry with the Navier-Stokes equation (conservation of mass, momentum, and energy) due to the high heating. Neural Networks can then be used to minimize the amount of data points needed to be computed. The neural networks can fill in the design space once it is trained properly with some inputs and outputs.

[ RoxanaGreenman/ARC - 43 - 09:51:10 ]
RE: [Shae-Shae/LamarUniversity] How do I gain access to such journals?
Most of these Journals are on the web -- or at least the titles of the papers and the abstracts. Do a search for AIAA and ASME and go to their home pages. Then just have "fun". Also, you can find all these journals in a good technical library.

[ RoxanaGreenman/ARC - 45 - 09:54:30 ]
RE: [NyyotaHolmes-Mr.Howard/HighlandParkHighSchool] I'm in a algebra class. I'm interested in knowing what math classes would i need to take to be in your feild?
You do need a lot of math to be an Aerospace engineer. In high school, I took algebra, geometry, trig, and calculus. But then in college I re-took Calculus. I basically took math all through my bachelors and Ph. D. Some other course I took in college are differential equations, simlitude, advanced applied math. But they were all fun and interesting. Just make sure you take them in the correct order because they are usually pre-requisites.

[ RoxanaGreenman/ARC - 46 - 09:56:08 ]
RE: [Shae-Shae/LamarUniversity] Oh, so one of the most important things you would do has to do with the intelegence of the craft?
Yes, the control system of the aircraft is very important. There are stability and control engineers who work on just that!

[ RoxanaGreenman/ARC - 48 - 09:56:59 ]
RE: [Shae-Shae/LamarUniversity] Are they readily availible to everyone?
Yes, you should have no problem locating the Journals, if you do, please let us know.

[ RoxanaGreenman/ARC - 50 - 10:01:09 ]
RE: [Shae-Shae/LamarUniversity] Would you please expand upon the neural network you spoke of earlier?
Neural networks (NN) are computational devices that are very good at predicting non-linear data once they are trained on a data set. The neural networks are trained by presenting input-output pairs to the networks. Then the NN adjust the connectivity weights between nodes until the error between the predicted value and the actual value of the output for a given input in minimized. Thus, they are used to fill in a design space that is sparse. They were designed to simulate the human nervous system.

[ Oran/NASAChatHost - 51 - 10:01:59 ]
EVERYONE, Roxana will be able to stay online with us for another 15-20 minutes today. For those of you leaving us, please let us know what you thought of today's chat at http://quest.arc.nasa.gov/qchats/qchat-surveys.

[ RoxanaGreenman/ARC - 52 - 10:02:20 ]
RE: [Shae-Shae/LamarUniversity] This network sound very interesting.
The NN are very interesting and it is amazing at how well they perform!

[ RoxanaGreenman/ARC - 54 - 10:04:06 ]
RE: [Shae-Shae/LamarUniversity] I thank you very much, Dr. Greenman, for your time and gift of information. I regret that I must go now.
Thank you for participating! I enjoyed it, it was my pleasure. I wish you the very best in your future career!

[ Oran/NASAChatHost - 57 - 10:09:06 ]
This concludes our chat with Roxana Greenman from NASA Ames Research Center. Thank you to everyone for joining us today!

[ Oran/NASAChatHost - 59 - 10:09:33 ]
A special thanks to Roxana for sharing her time and expertise with us online today.

[ Oran/NASAChatHost - 60 - 10:10:46 ]
Please let us know what you thought of today's chat by using our online feedback surveys at http://quest.arc.nasa.gov/qchats/qchat-surveys.

[ RoxanaGreenman/ARC - 61 - 10:11:17 ]
RE: [Ann/AERO-Ann/AERO] I'd like to thank you too. would you care to comment on this week's historic space launches?
Thank You too Ann! It was my pleasure. Thank you for your questions. I think it is just remarkable that Senator Glenn is going up again! He is a great hero to all of us as well as the other astronauts.

[ Oran/NASAChatHost - 62 - 10:11:46 ]
To learn about upcoming chats with ADTO experts, check the ADTO chat page at http://quest.arc.nasa.gov/aero/chats. To learn about chats with other NASA experts, check our schedule of events page at http://quest.arc.nasa.gov/common/events.

[ Oran/NASAChatHost - 63 - 10:13:04 ]
Once again, we would like to than everyone and Roxana for joining us for today's chat. Please join us on Wednesday, November 4 at 4:00 p.m. Pacific Time for our next ADTO chat with Susanne Ashby from NASA Ames Research Center.


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