How to Beat a Speeding Ticket for Motorists

[Argentum Vulpes]

Ok so here is the next term.

Alligatoring

Hint: It has nothing to do with the animal, or Ham radios.

 

[flatmaster]

Alligatoring is the drill in basic training where the GI's crawl under barbed wire. They look like alligators walking on their elbows.

 

[Argentum Vulpes]

Not what I'm looking for Flatmaster.

Next hint,
It is a defect to some people, and some people want it.

 

[Danger]

Please tell me that it isn't an S/M version of "scissoring" from the GLBT culture...

 

[Ivan Seeking]

Not what I'm looking for Flatmaster.

Next hint,
It is a defect to some people, and some people want it.

Paint cracking?

 

[Argentum Vulpes]

Yup you got it Ivan. It is a paint defect caused when the top coat is more rigid then the bottom coat, causing a regular cracking pattern resembling alligator skin.

 

[Ivan Seeking]

Porpoising

Context -
Industrial

Additional clue
Mathematical

 

[Ivan Seeking]

2nd clue:
Proportional

 

[Ivan Seeking]

Next clue: Motion

 

[flatmaster]

Proposing is some sort of motion on a crankshaft. From the side, you may see just the top of the crank arm going up and down. The motion looks like a porpoise continually breaking the surface of the water.

When on the beach, proposing is the fastest way to move through intermediate depth water that is too deep for running, but not deep enough for swimming.

 

[Ivan Seeking]

another clue: Loop

 

[Ivan Seeking]

uh oh, too obscure?

big clue
PID

 

[Jonathan Scott]

I associate "porpoising" with the undulating motion of a servo which is supposed to be in a specific position but the feedback mechanism has sufficient delay in it to cause overshoot.

 

[Ivan Seeking]

I associate "porpoising" with the undulating motion of a servo which is supposed to be in a specific position but the feedback mechanism has sufficient delay in it to cause overshoot.

Close enough!

Specifically, I was going for the sinusoidal oscillation that results in some process value for a system, when the proportional term is set too high in a PID [proportional-integral-derivative] loop or controller, for motion and other applications. It could refer to oscillations in pressure, temp, position, speed, solution strength, flow rate, or any variable in a dynamic system controlled with this type of algorithm, which in industry is pretty much any dynamic system where a set point value must be maintained. One common PID equation used is

where
K_p: Proportional gain, a tuning parameter
K_i: Integral gain, a tuning parameterK_
d: Derivative gain, a tuning parametere:
e: Error = SP - PV [set point - process value]
t: Time or instantaneous time (the present)
tau: Variable of integration; takes on values from time 0 to the present t.
http://en.wikipedia.org/wiki/PID_controller

A subject close to my own heart, the thing that sent me on the path to self-employment was a custom PID equation and algorithm that I wrote for a difficult problem. I also found an error in the Rockwell PID algorithm used in some of their industrial computers, so there is a firmware revision out their with my name on it [literally].

But you are correct that a number of problems can result in porpoising of the process value. And one that is often missed [that has made me a good bit of money in correcting] is not properly allowing for or calculating the feedback time. The PID loop update times are too short and are responding to data that you haven't actually received yet, so you continually get overshoots. So your example is a particularly good one.

Just fyi, another cause can be "windup" in the integral term, where either startup or some deviation in the normal process, or an abrupt change, can cause the value of the integral term to windup [continually add], causing a long delay in the recovery. This in turn can result in windup in other direction, which leads to long-term oscillations. Most controllers now come with anti-windup features but they still have to enabled, or some escape routine added to the code to prevent this if you're writing your own routine. Often you can just set a limit for the max/min value of the integral term.

 

[Jonathan Scott]

OK, next one is "shoe shine" used as an adjective.

 

[Jonathan Scott]

As could be guessed, this term relates to one of my primary interests

 

[Jonathan Scott]

"Shoe shine" is one alternative to the normal technique. "Hooked" is another.

 

[lisab]

Is that a bowing technique?

 

[Jonathan Scott]

Is that a bowing technique?

Yes, it is indeed. It is a string instrument bowing technique for alternating short and long notes, in a "di-dum di-dum di-dum" pattern.

The normal rule is that the stronger (long) note is a down bow and the short note is an up bow. However, in faster music, this can be awkward, mainly because they are different lengths.

One alternative is to use "hooked" bowing, in which the short note follows in the same bowing direction as the preceding long note (but the bow is stopped or lifted between the two notes so that they are not joined). This is very common.

A less common alternative is to use a down bow on the short note, bouncing to an up bow on the long one. This typically gives a very brisk effect of a rapid pair of notes followed by a gap, and gives a more uniform effect than hooked bowing because each pair is bowed in exactly the same way. This action of a short down stroke bouncing to an up stroke is known as "shoe shine" bowing because of the way the hand moves.

OK, you're next, lisab.

 

[Danger]

Is that a bowing technique?

That response made absolutely no sense to me any time that I read it. Then when Jonathan agreed, I realized that there was an "L" missing in what I thought you had typed. I really should wear my glasses more often.

 

[lisab]

OK, this one is petty obscure:

Cheese.

First hint: It's in the culinary realm but has nothing to do with dairy.

 

[Danger]

It's in the culinary realm but has nothing to do with dairy.

I'm not sure if that rules out a yeast infection or not...

 

[lisab]

I'm not sure if that rules out a yeast infection or not...

Yeast has its place in this process.

 

[lisab]

Yeast has its place in this process.

In the olde days, straw had its place, too. It provided a path of escape.

 

[OCR]

It's in the culinary realm but has nothing to do with dairy.

Stinky tofu?... I know, wrong!



OCR... lol

 

[Danger]

I'm thinking on it, but so far... nuthin'.

 

[lisab]

The "cheese" is actually a by product, and is often fed to chickens or other farm animals.

 

[collinsmark]

Here's a guess. I'm not sure if it fits though.

Is it a part of a cider press? (fruit press?)

"A stack of cloth-wrapped, mash-filled 'bags' layered between pressing discs (a.k.a., racks) is traditionally referred to as a cheese."

http://www.whizbangcider.com/2012/07/how-to-make-proper-cheese-for-pressing.html

[Edit: I imagine that maybe the remaining, fruity solids that are leftover after the pressing/squeezing takes place might still be considered the cheese, perhaps. (or "pomace"?)]

 

[lisab]

Here's a guess. I'm not sure if it fits though.

Is it a part of a cider press? (fruit press?)

"A stack of cloth-wrapped, mash-filled 'bags' layered between pressing discs (a.k.a., racks) is traditionally referred to as a cheese."

http://www.whizbangcider.com/2012/07/how-to-make-proper-cheese-for-pressing.html

[Edit: I imagine that maybe the remaining, fruity solids that are leftover after the pressing/squeezing takes place might still be considered the cheese, perhaps.]

Excellent, yes that's it (the bolded text)!

You're up.

 

[collinsmark]

You're up.

I'm not sure if this is going to be hard or easy. But just in case, I'll ensure plenty of hints.

What is the shoulder? Context: used in the phrase, "over the shoulder."

• It's pretty abstract. You can't hold this type of shoulder in your hand.
• It's kind of technical.
• It's even sort of mathematical.
• Ironically though, most people who study (or have studied) the subject matter are not necessarily technically minded, and are in fact artists. This may have been considered as one of those areas where mathematics has some real-world applications.
• It is almost always undesirable for things to be "over the shoulder." (I'll concede that there can be some rare exceptions, however.)

Hint:
It involves a dying art. Well, that's not entirely true. In a more general sense the art is flourishing. As a matter of fact the art is more popular now than it ever has been in the history of all human kind. It's just that the particular aspect of the art where the phrase "over the shoulder" would apply is dying a speedy death. Some have argued that it is already dead.

 

[flatmaster]

When I hear "mathematical, but used by artists", I think "Fractal" or "Tessellation" but neither of thoes seems to fit.

My guess is that "over the shoulder" refers to a specific camera angle where the camera is looking over one of the character's shoulders and we see what they may be seeing.

 

[collinsmark]

When I hear "mathematical, but used by artists", I think "Fractal" or "Tessellation" but neither of thoes seems to fit.

Nope. Neither fractals nor tesselation is involved. (The art of which I speak predates modern computers.)

"The shoulder" almost always involves a different, particular mathematical function though. Here's a hint. Before the advent of electronic calculators this mathematical function was used pretty commonly by most anybody doing numerical math. So even non-technically minded, professional artists would probably be at least somewhat familiar with its use.

My guess is that "over the shoulder" refers to a specific camera angle where the camera is looking over one of the character's shoulders and we see what they may be seeing.

Sorry, but that's not the same "over the shoulder" to which I refer. My "shoulder" does not actually involve a human shoulder.

That said, you're really close to the correct subject matter.

Here's another hint: The aspect of the art that's dying fast (or is arguably already dead) has only been doing so for maybe a decade or two (I'd say closer to a decade and a half, but its hard to pin down).

 

[flatmaster]

Maby shoulder refers to a step function. The art application would be a film camera that must move film step-wise rather than continuously. If something is "over the shoulder" the film is out of synch with the shutter and you see two halves of a cell rather than a single cell.

 

[Office_Shredder]

Over the shoulder is when you expose a picture for too long?

 

[collinsmark]

Over the shoulder is when you expose a picture for too long?

Correct. And I suppose that that's close enough that I'll give the complete answer.

Photographers used to pick the film they were going to use for a shoot based on the film's "Density vs. log E" characteristics.

The curve used to look similar to this one,

found in this link.
http://en.wikipedia.org/wiki/Sensitometry

Any photographer worth his or her weight used to know about H-D curves. The top part of the curve is known as "the shoulder" where overexposure compresses the details of any highlights. The opposite of the shoulder is "the toe" and any exposure in this region compressed details of the shadows, and was called "under the toe."

If a photographer makes an exposure mistake using film, he/she could often get some of the detail back in the darkroom print, but often at the expense of contrast. That said, photographers such as Ansel Adams characterized all his film and equipment to the point where he chose the ideal equipment for the particular scene, such that the exposure extended all the way from toe to the shoulder without any significant saturation -- making the very most of the equipment. He didn't stop there either. The same attention to detail was done with his darkroom.

Today though, photography is changing. CMOS and CCD, electronic sensors usually have a different shaped curve. The linear region of the curve typically extends all the way up to the top where it sharply plateaus. Photographers rarely call exposure in this plateau region "over the shoulder" anymore, since there isn't even really a shoulder. Instead they're just called "blown highlights." And once they're blown, they're blown. There ain't any amount of Photoshop that will get them back (without faking it).

On the other end, electronic sensors don't have a toe either. The linear region just keeps going down and down forever, or until it's just random noise. This makes digital sensors well suited for astrophotography where long exposures in low light situations are the norm.

Okay Office_Shredder, your move.

 

[Office_Shredder]

Lensing

As you might guess it has to do with focusing light. But this particular form of lensing can be quite problematic for solar power enthusiasts

 

[flatmaster]

I suppose this is the type of lensing that occurs with water droplets on the panel. A dry panel would have even lunumous flux over it's entire area, but a panel covered in water droplets would experience pin points of high intensity light caused by lensing from water droplets. I suppose this light may be intense enough to damage this part of the solar array.

 

[Office_Shredder]

Water droplets can indeed be the cause of this lensing, but not when placed on the array. In fact in certain applications solar arrays are sprayed with water to cool them off - this helps to increase their efficiency

 

[Office_Shredder]

A hint: If you can see this lensing, it will usually pass you by quite quickly

 

[Office_Shredder]

And the weatherman can tell you whether you should expect to see any

 

[collinsmark]

Okay, I'll bite with a nearly wild guess. (It's been about a day with no guesses, so I'll give it a go.)

Even the dry atmosphere can refract light. And this is called atmospheric lensing.

When looking at the sun at sunset or sunrise, you're not actually looking toward the true position of the sun at the time. The direction to the sun is actually lower than it looks. This is because the atmosphere bends the sunlight "down" (so to speak) making the direction to the sun appear farther up.

If you have a simple photovoltaic panel (PVP) and you want to get maximum efficiency, its best to make the PVP's surface normal to the direction of the sunlight. For most situations, this is easy enough by mounting the PVP on a equatorial mount, and have it track the Earth's rotation using a simple timer.

But such a setup would not be as efficient as it otherwise could be around sunrise or sunset due to the fact that the sunlight is not coming from the true direction of the sun, because of atmospheric lensing. That's not a big deal though. All that is lost is a little efficiency.

But wait, it gets weirder. Potentially a lot weirder.

Depending on the weather conditions anywhere between your location and down past the horizon, this effect can be less or more pronounced such as discussed in this link (The sun has already set, and yet then there's another sun! WTF?):

http://www.spaceweather.com/gallery/indiv_upload.php?upload_id=37810

It doesn't end there either. Many of you have probably seen a mirage at some time or another. A mirage can be considered another form of [atmospheric] lensing. When air is warmed by a hot surface, it can bend the light up making an additional image of the sun* (or sky or whatnot), seemingly coming from a pool of water (or mirror) on the ground (where no pool of water or mirror exists).

*(Edit: the actual scenario where an additional image is of the sun itself is not likely to happen from a hot ground mirage, since the ground usually starts cooling off by sunset. But I'm just saying that the atmospheric lensing in the first link is not altogether different than a mirage.)

So how can this be problematic for a solar power enthusiast?** Well, there are more ways to harness solar power than a simple PVP.

One of them is concentrated photovoltaics

http://en.wikipedia.org/wiki/Concentrated_photovoltaics​

And there's also concentrated solar thermal.

http://en.wikipedia.org/wiki/Concentrated_solar_power​

Both of these methods require proper tracking of the sunlight.

Improper tracking of the sunlight, combined with concentrating that light, can cause bad things to happen. Very bad things: things such as awful fires, melting metal/concrete etc. There's going to be a focused beam of sunlight somewhere, so you'd better darn well make sure that it lands on something you want it to, and goodness sake not on something you don't want it to.

But what if (due to atmospheric lensing) there are suddenly two suns? Now that's a problem!

That's my guess anyway.

**(Edit: And even for a single non-concentrated PV system, such atmospheric lensing might throw off an automatic feedback sunlight tracking system, if the mount contains such a feedback tracking system. No actual danger in this situations, but I imagine it could completely throw off the mount's tracking abilities for awhile.)

 

[Office_Shredder]

collins, that's a pretty awesome answer but unfortunately wasn't the one I was thinking of My lensing is a bit more of a mundane process that's named after the meteorological phenomenon that spawns it.

It's pretty hard to find on google, I highly recommend using quotation marks when searching

 

[lisab]

Is it related to rainbows?

 

[OCR]

Sun dog??

http://en.wikipedia.org/wiki/Sun_dog



OCR

 

[Office_Shredder]

Sun dogs and rainbows are both tangentially related to the lensing I am referring to, in that they are caused by refraction of light through water in the atmosphere, and so is this effect. This lensing often requires a more noticeable concentration of water to occur though.

(Also sun dogs may have a similar effect on solar power as this lensing but I'm not sure about that so take it with a grain of salt)

 

[OCR]

requires a more noticeable concentration of water

Haar, haar, haar... lol



OCR

 

[OCR]

Ignore the ignorant guess at post # 196...
OCR... lolhttp://en.wikipedia.org/wiki/Haar_(fog)

 

[Office_Shredder]

If that haar was located a couple miles in the sky it might be perfect :p

 

[flatmaster]

Lensing from clouds? I thought cloud droplets were small enough to cause scattering rather than refraction.

 

[flatmaster]

Every cloud has a silver lining

http://en.wikipedia.org/wiki/Silver_lining_(idiom )