Chris Penningroth’s Weltanschauung » Engineering

Clarke’s Third Law Applied

Chris Penningroth — Mon, 11 Aug 2008 10:32:20 +0000

It appears that the highly-desired Cloak of Invisibility that my Dungeons and Dragons characters were searching for over 25 years ago was finally found in a lab at UC-Berkeley.

No wonder Ug the Barbarian-Ranger never found it, it wasn’t in a dragon’s lair–it was in an ivory tower!

Click here for more Arthur C. Clarke quotations.

Wild Ride

Chris Penningroth — Sun, 13 Jan 2008 11:31:11 +0000

Here’s a computer-generated video of the F-15 that broke up in mid-flight back in November via Air Force AimPoints and CNN.

Keep Working On It

Chris Penningroth — Thu, 01 Nov 2007 12:35:45 +0000

Some guy built a 21′ replica of an X-Wing. Good on him!

Too bad this looks like it’s just an oversized Estes model rocket.

When someone builds an actual X-Wing, let me know. I know of a canyon near Big Bend, TX that resembles the Death Star equatorial trench.

Test Anxiety

Chris Penningroth — Mon, 30 Oct 2006 12:34:49 +0000

I just took my second exam in my controls class. Somehow, I’ve managed two straight times to convince myself I understood the material well enough to do great on an exam. That, and he allowed us to have a table of integrals, a table of Laplace transforms, and a crib sheet filled with equations (plus a matrix algebra crib sheet).

Somehow, I still managed to find that the determinant of a matrix was zero, so the inverse didn’t exist, and had to hope that I managed to clip that curveball into at least a base hit. Then, from out of left field came hyperbolic sine! What the. . . !? I don’t think I’ve seen one of those since orbital mechanics class back in 1994. By the way, the table of integrals weren’t quite as helpful as a table of derivatives would have been!

As long as there are exams, there will be prayer in school. Or at the testing center on base.

MatLab

Chris Penningroth — Sun, 24 Sep 2006 06:21:46 +0000

MatLab is an extremely versatile program, it’s actually almost like another computer programming language. It is far, far easier to perform arithmatic operations with it than FORTRAN. It’s especially good at matrix operations. Just type in the matrix, and off it goes!

Naturally, this program has replaced FORTRAN as the bane of my computing existence. Lines of code that work fine on the professors computer don’t run on mine. The controls toolbox seems to be installed on my computer, but the control functions are recognized as variables, not operators, when I try to use them. I’m sure there’s a very simple explanation for all of the problems I end up having. Maybe I just need to upgrade from version 6.0 to version 7.1.

Why is it that spending several hundred dollars always ends up being my solution to my computer problems?

Update: Apparently you can type ‘ver’ in the command window and MatLab will tell you what toolboxes you have installed (or you can uninstall it and the first menu page also lists the uninstall options, including toolboxes). As luck would have it, I don’t have the toolbox I need. It looks like I get to pay for an upgrade. Great! Just what I was hoping for!

Newton

Chris Penningroth — Tue, 12 Sep 2006 10:44:42 +0000

Sir Isaac Newton is at once something of a hero and the bane of my existence. My latest problem has me trying to use integration by parts of natural exponentials and trigonometric functions. The last time I had to do this in earnest was 1994 (if that late). In a way it’s been fun going back and re-learning all of the Calculus and differential equations I’ve forgotten. On the other hand, it’s time-consuming to have to go back and look it up, and it causes my homework to be late more often than I care to admit.

If anyone in a small town called Rolla runs into a guy named Wyatt, give him a hearty handshake for me! I don’t think I’d've figured out that one problem without him pointing out what example to follow!

Partial Fraction Expansion

Chris Penningroth — Tue, 05 Sep 2006 13:09:28 +0000

If anyone out there can explain how to perform partial fraction expansion of a couple polynomials, please call me! I’ve got a problem that’s giving me fits!