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     Biker_bob |
I thought it was those who can't do, teach, those that can't teach, teach gym!  | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Jlnance |
Jinance: Wow, you were in the minority if you loved controls w/complex number et al (well, speaking for the MEs anyway)... Well, I'm an EE so by the time I got to controls I was well versed in complex numbers. The one that drove me nuts was modern control theory which was entirly matrix based. We would do awful things like find the eigen values of matrices by hand. And of course they would end up being complex. There is only so much math I can do before I make a mistake, and all those problems were way past my limit. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Dmcutter |
Jiminy, JLNance....if you didn't ride a Buell I would think you were a complete nerd. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Dr_greg |
Wow, somebody that speaks my language! JL, finding eigenvalues of matrices greater than 2x2 is why they invented computers and software like MATLAB! BTW, MATLAB "inventor" Cleve Moler used to be CS Department chair here at UNM ('72-'85). And for the rest of you, just feel secure in knowing (or hoping) that the linearized eigenvalues of your moto steering dynamics better darn well be in the left half of the complex number plane (JL knows that!) Why? No tankslapper like the one which fractured my humerus in 2003 (bone was sticking through a hole it tore in my leathers). | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lovehamr |
BSED, Cop and firearms guy with some experience in finite strength analysis (blowing stuff up yeehaa). My oldest son is taking that a step further, he's an EOD tech with the USAF currently in Iraq. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Yamahammer490 |
Although I've moved into corporate management, my guys refer to me as a "recovering engineer" because you really can't take it out of you once it's in. I'm an ME. In the spirit of the holidays I offer this recipe that only an engineer can appreciate: Chocolate Chip Cookies Ingredients: 1) 532.35 cm3 gluten 2) 4.9 cm3 NaHCO3 3) 4.9 cm3 refined halite 4) 236.6 cm3 partially hydrogenated tallow triglyceride 5) 177.45 cm3 crystalline C12H22O11 6) 177.45 cm3 unrefined C12H22O11 7) 4.9 cm3 methyl ether of protocatechuic aldehyde 8) Two calcium carbonate encapsulated avian albumin coated protein 9) 473.2 cm3 theobroma cacao 10) 236.6 cm3 de-encapsulated legume meats (sieve size #10) To a 2-L jacketed round reactor vessel (reactor #1) with an overall heat transfer coefficient of about 100 BTU/F-ft2-hr, add ingredients one, two and three with constant agitation. In a second 2-L reactor vessel with a radical flow impeller operating at 100 rpm, add ingredients four, five, six and seven until the mixture is homogenous. To reactor #2, add ingredient eight, followed by three equal volumes of the homogenous mixture in reactor #1. Additionally, add ingredients nine and ten slowly, with constant agitation. Care must be taken at this point in the reaction to control any temperature rise that may be the result of an exothermic reaction. Using a screw extrude attached to a #4 nodulizer, place the mixture piece-meal on a 316SS sheet (300 X 600 mm). Heat in a 460K oven for a period of time that is in agreement with Frank & Johnson's first order rate expression (see JACOS, 21, 55), or until golden brown. Once the reaction is complete, place the sheet on a 25C heat-transfer table, allowing the product to come to equilibrium. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Jlnance |
Jiminy, JLNance....if you didn't ride a Buell I would think you were a complete nerd. The reason I ride a Buell is so I won't be a complete nerd.  | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Jlnance |
finding eigenvalues of matrices greater than 2x2 is why they invented computers and software like MATLAB! You know, the thing that pissed me off is I had a calculator that would have figured them out. The prof just wouldn't let me use it.  The linearized eigenvalues of your moto steering dynamics better darn well be in the left half of the complex number plane (JL knows that!) I don't believe I've finally met someone else who knows about left half plane poles. I've only been looking since 1989. It has never proved to be a very good conversation starter with the ladies. Go figure. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Jlnance |
The sad thing is I think I could follow that recipe. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Whodom |
I don't believe I've finally met someone else who knows about left half plane poles. I've only been looking since 1989. It has never proved to be a very good conversation starter with the ladies. Go figure. The sum total of my knowledge retention from ME 401 (Automatic Controls) is that a pole in the right-hand half plane is a bad thing.  | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Dmcutter |
so do you guys actually use that i, square root of negative one thing? I never understood what practical use that actually had. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Jlnance |
The sum total of my knowledge retention from ME 401 (Automatic Controls) is that a pole in the right-hand half plane is a bad thing. OMG, there are 3 of us! | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Jlnance |
Dmcutter - Yes, EEs use it all the time. I suspect MEs use it less (and thats just a guess), but they still use it. Here is the short answer on what it's good for. Say you have a structure with springs and weights (ie a motorcycle suspension, a bridge, or your garrage door), and you want to know how it moves when you do something to it. No matter how complex the structure is, its fairly trivial to write a differential equation that describes it's movement. Unfortunatly differential equations are a PITA to solve. There is a trick you can use to solve certain types of differential equations which lets you transform them into regular algebra. But it's algebra with complex numbers (that sqrt(-1) thing). But even with complex numbers, it is a lot easier to work with algerbra than it is differential equations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Whodom |
The sum total of my knowledge retention from ME 401 (Automatic Controls) is that a pole in the right-hand half plane is a bad thing. Ooo, ooo! I remembered something else. If you get to the lab early, and find 3 cool-looking motor gizmos wired together with a standard household two-prong plug on the end, and plug it into a wall socket, you will hear "BZZZZT!" and smell ozone. A few minutes later, the professor will walk in, explain that he is going to be demonstrating the uses and operation of servos today, then he will open the cabinet and pull out this huge contraption which turns out to be a 60 hz / 400 hz converter. He will then power it up and plug the servos into it, and be puzzled at why they don't work. Then he will look around and ask "You guys didn't plug these into a wall socket, did you? Oh well, I guess you let the smoke out of them." When you look puzzled, he will explain the "smoke theory" of electrical devices. That's how I learned about electricity. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Jlnance |
The smoke theory is a fundamental principle of EE. So is the principle of not admitting you plugged it in if he didn't see you. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Blake |
"the "smoke theory" of electrical devices." LOL! That's a new one for me. Great stuff! All I recall from my engineering education is that shit won't flow uphill and you can't push on a rope. Will add the "smoke theory" of electrical devices to that.  | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Whodom |
Smoke Theory of Electrical Devices- Virtually all electrical devices (motors, switches, transformers, wire, etc.) work because of special smoke which is encapsulated inside them during the manufacturing process. If these devices fail due to age, misuse, or defects, the smoke will be released and the device will no longer function. Hence, an operator-induced failure of an electrical device is often referred to as "letting the smoke out of it". I have let the smoke out of a few electrical devices in my day. (Message edited by whodom on December 15, 2005) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Dmcutter |
That is hilarious. That's better than the Navy's PFM. In a naval science class one of the students asked the instructor how submarines navigate under polar ice caps. He said it was PFM, pure f'ing magic. JLNance, would that be your Laplace Transformation? Or is that the natural child birth method? | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Dr_greg |
As I prepare to teach complex numbers to my 12-yr old son (it's time), I'll pass on the reason why we absolutely need so-called "imaginary" numbers: 1. The only reason you need negative numbers is so you can solve equations like: x+2=0...the solution is x=-2. Without the "-" you can't write down the solution. 2. Likewise, the only reason you need "imaginary" numbers is so you can solve: x^2+4=0 (the ^2 thing means "squared")...the solution is x=i2. Without the "i" you can't write down the solution. Think of "i" as an operator, just like "-". Actually "i" is easier than "-": it just rotates by 90 degrees on the complex number plane, while "-" rotates by 180 degrees! End of lecture. Tuition is, let's see...whatever you think it's worth! Since I'm in a good mood we'll even skip the final exam. Merry Christmas to all! Even to us nerdy engineers... | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bigdaddy |
Jim, Did you ever get the Diffie-Q ball cap? If you had issues let me know. I *may* have an extra one at the house. Love them Diffie-Q's,,,, G2 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Jerseyguy |
"Letting the smoke out" is our term for the first time we power up a new machine control system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Djkaplan |
Understanding Engineers - Take One Two engineering students crossing the campus when one said, "Where did you get such a great bike?" The second engineer replied, "Well, I was walking along yesterday minding my own business when a beautiful woman rode up on this bike. She threw the bike to the ground, took off all her clothes and said, "Take what you want." The first engineer nodded approvingly, "Good choice; the clothes probably wouldn't have fit." Understanding Engineers - Take Two To the optimist, the glass is half full. To the pessimist, the glass is half empty. To the engineer, the glass is twice as big as it needs to be. Understanding Engineers - Take Three A pastor, a doctor and an engineer were waiting one morning for a particularly slow group of golfers. The engineer fumed, "What's with these guys? We must have been waiting for 15 minutes!" The doctor chimed in, "I don't know, but I've never seen such ineptitude!" The pastor said, "Hey, here comes the greens keeper. Let's have a word with him." "Hi George! Say, what's with that group ahead of us? They're rather slow, aren't they?" The greens keeper replied, "Oh, yes, that's a group of blind firefighters. They lost their sight saving our clubhouse from a fire last year, so we always let them play for free anytime." The group was silent for a moment. The pastor said, "That's so sad. I think I will say a special prayer for them tonight." The doctor said, "Good idea. And I'm going to contact my ophthalmologist buddy and see if there's anything he can do for them." The engineer said, "Why can't these guys play at night?" Understanding Engineers - Take Four What is the difference between Mechanical Engineers and Civil Engineers? Mechanical Engineers build weapons and Civil Engineers build targets. Understanding Engineers - Take Five "Normal people believe that if it ain't broke, don't fix it." Engineers believe that "if it ain't broke, it doesn't have enough features yet" Understanding Engineers - Take Six An engineer was crossing a road one-day when a frog called out to him and said, "If you kiss me, I'll turn into a beautiful princess." He bent over, picked up the frog and put it in his pocket. The frog spoke up again and said, "If you kiss me and turn me back into a beautiful princess, I will stay with you for one week." The engineer took the frog out of his pocket, smiled at it and returned it to the pocket. The frog then cried out, "If you kiss me and turn me back into a princess, I'll stay with you and do ANYTHING you want." Again the engineer took the frog out, smiled at it and put it back into his pocket. Finally, the frog asked, "What is the matter? I've told you I'm a beautiful princess, and that I'll stay with you for a week and do anything you want. Why won't you kiss me?" The engineer said, "Look, I'm an engineer. I don't have time for a girlfriend, but a talking frog, now that's cool." | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Blake |
Come on Doc! We got math formatting here just for you! Try... \+{exponent or superscript here} and \-{subscript here} We even have integrals and stuff...
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| Jlnance |
JLNance, would that be your Laplace Transformation? Yes, that is the Laplace Transformation. I LOVE the symbols Blake. But you left out the integral. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Whodom |
While we're on the subject, and in the spirit of the Christmas season, see the file below for "What an Engineer Does for Christmas". Christmas.pdf | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Blake |
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| Lowflyer |
I'm not an engineer, but I do play one at work. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Dr_greg |
Blake, sorry for not using classy formatting here, but anyone ever heard of this jingle...you have to me a math/science geek to pronounce everything so the rhythm is right: "e to the x, dy dx, e to the y dy, cosine, secant, tangent, sine, 3.14159..." That's all I know, but I'll bet there's more. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Electraglider_1997 |
Must be from the same linguist that wrote: The cube of the tube is inversely proportional to the angle of the dangle. (Message edited by electraglider_1997 on December 21, 2005) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Dmcutter |
Saw a real funny cartoon one time, I think it was in NC State's paper...there was a kid doing calculus and drinking a beer, and a cop was citing him for deriving under the influence. |
