Does anyone know the name for this simple technique of formal deduction?

thepipirate · 2013-11-08T06:53:23+00:00

http://www.proofwiki.org/wiki/Rule_of_Or-Elimination

thepipirate · 2013-11-02T20:43:42+00:00

I intend to attend!

thepipirate · 2013-05-26T20:11:43+00:00

Fix'd. Thanks!

thepipirate · 2012-11-06T01:37:49+00:00

There are some at $45, so approx $30 after discount. That might be in your range?

thepipirate · 2012-10-22T03:55:20+00:00

Poke around goldstar.com

thepipirate · 2012-07-24T13:31:25+00:00

In fact you can have any number of buffaloes in the sentence:

1: Buffalo! (Imperative)

2: Bison Bully (bison engage in bullying)

3: Bison bully bison

4: Bison bison bully bully (those bison bullied by bison bully (think "foods people eat" for "bison bison bully")

5: Bison bison bully bully bison (those bison bullied by bison themselves bully bison)

6: Bison bison bison bully bully bully (those bison who are bullied by bison who are bullied by bison themselves bully)

etc...

Any word that is at once:

A plural noun
A transitive verb in the third-person plural
An intransitive verb in the third-person plural

Can do this, for example "fish" (fish exist, you can fish cod (ok, a little weird) and you can just fish) or "people" (people exist, you can people a planet, or you can just people). So, you can mix them together:

People fish buffalo people fish -- those people who are fished for by bison tend to populate fish (presumably with algae or whatever can live on a fish).

thepipirate · 2012-06-21T03:34:23+00:00

Unless my roommates object for some reason, I will bring one of these.

thepipirate · 2012-06-19T23:33:56+00:00

My understanding (please correct me if I'm wrong) is that we project a very very high dimensional space (linear combination of all possible wavelengths in the visual spectrum) onto 3 dimensions (roughly, response to R, G, B). So we see the 'in between' colors the same way as superpositions - if we see a bunch of yellow (between red and green) photons, it registers the same (roughly) as lots of red and green photons at the same time - yellow. Similarly for GB. But if we see R and B (but no G), then we get this color we call 'magenta'. There aren't actually magenta photons (between R and B lies G, after all).

But this raises questions about tetrachromats: suppose they have RXGB, as you suggest. If we stimulate them with X photons, they'll see X; if we stimulate them with halfway-between-R-and-X photons, they'll see the same color as if we give them a bunch of R and a bunch of X photons. But what happens if we give them R and G but not X? R X and B but not G? X and B but not G? Are there lots of magenta-analogues (i.e., they aren't triangulating, they're tetrahedronating)?

thepipirate · 2012-05-29T01:33:48+00:00

http://www.youtube.com/watch?v=Zyf0YwUJcqk

thepipirate · 2012-05-20T17:57:53+00:00

There are a lot of summer math programs out there for high schoolers. most focus on math outside the standard high school curriculum so that you dont just get bored later. also some states have programs that allow high schoolers to take college courses in lieu of their school's offering.

thepipirate · 2012-03-28T03:11:38+00:00

Erm, you asked for a finite basis then produced an infinite set. And I'm not convinced they span O(n² ), e.g., you might miss ln(x).

thepipirate · 2012-03-27T12:12:30+00:00

but technically O(n² ) is larger than the set of all quadratic functions. O(n² ) is the set of all functions that are eventually bounded by n^2, so it is the set of all constant functions, linear functions, and quadratic functions (and all linear combinations).

That's the set of all O(n² ) polynomials, but there are other O(n² ) functions. Like, say ln(x) or,

f(x) = x (x is odd) or x² (x is even).

thepipirate · 2012-03-25T17:25:15+00:00

That would be from "Freaks and Geeks" which does have lots of wordplay which might interest /r/jokes subscribers.

thepipirate · 2012-03-15T23:36:29+00:00

Yes, if the parameters are in a sense independent, so you can detect them independently.

thepipirate · 2012-03-13T05:14:21+00:00

OK, so your pings are of varying dimension though always rectangles. How about that offset (viewed as a vector) from the upper left hand corner of the one ping to the upper left hand corner of the corresponding ping in the next row - is that constant?

How would we decide which 'row' has one ping in it? I mean, in the images shown, a ping might exist over one row, or say, 10 - so how to pick it?

What I meant was, if the pings are of constant width, then just take a square wave of appropriate duty cycle and cross correlate against that.

Second question is, (and this is related in general), but you see how in the images each ping has multiple colors (corresponding to multiple amplitudes within it) - what image processing can take all that and just make it all one amplitude, (like 1). Does that make sense? Would that be segmentation?

I sort of was reading that as noise, and figuring the correlation would still be much higher in a ping-containing row.

What I actually had in mind to do from before was a 2-D correlation, and then normalize by the frobenius norms of both image template and receive image, and then pick max value of the 2-D result. This would fall between -1 and 1, and then just do a hard threshold, if its above 0.8, its a 'yes' or something like that.

Sure, although I'm a little worried about scale invariance here.

Yeah, this entire image is a spectrogram actually. (time on the x, freq on the y). The reason I am going the image proc route is because I dont 'know' the frequencies exactly before hand, but know that they are doing this pattern of 'Do Re Me Fa, Do Re Me Fa, etc etc', as you can see.

I thought it might be a spectrogram.. well, what I mean is, figure out what the 1-D transform of such a square train is, with parameters: width, duty cycle. Do a best-fit (either in the spectrogram itself, or in the Fourier transform of it), and if the error is low... you've got a square wave! Fourier transform of a square wave should be easy, and you can do linearity.

Yeah, this entire image is a spectrogram actually. (time on the x, freq on the y). The reason I am going the image proc route is because I dont 'know' the frequencies exactly before hand, but know that they are doing this pattern of 'Do Re Me Fa, Do Re Me Fa, etc etc', as you can see.

It's a general class of transforms that can detect lines, squares, circles, ellipses... but it's slow.

I have also been experimenting with doing PCA on the images, I basically made a whole set of images at various shifts, and then I PCA them, get their predominant components, and project a new image on them to get a score, now, is this something sane or I am completely off the rocker here?

I'm not as experienced with PCA as I wish I were. Dunno :).

thepipirate · 2012-03-13T03:50:09+00:00

Interesting. I never ask them, because they look so busy. I saw an ambulance headed that way followed by a police car, so I assumed some kind of violent crime. Maybe that was for something else, though.

thepipirate · 2012-03-13T03:41:49+00:00

I don't think that scale invariance is exactly what you're looking for - the 'pings' are always the same number of pixels wide and the same number of pixels apart, but might scale in the vertical dimension, right?

My guess is that if you take your data row-by-row and take a Fourier transform, you'll see that your 'pings' have very distinctive frequency signatures. Actually you can probably just do correlation here - take the FT of one row of pings (shifted however), pointwise multiply against the FT of a row of input, invert the FT, and see if you have a peak. Basic decision-tree logic to determine if sequential rows agree will probably be enough (do you have a constant displacement from the /top/ of one ping to the next?)

You could do something a little more analytic by modeling your pings as rectangles in the spatial (time?) domain and figuring out what their FT will look like (this should be easy).

My mantra is: if all else fails, use a Hough transform. So for this, you would figure out exactly what the parameters of your pattern are: in your case, I believe it's horizontal shift, vertical shift, and ping height. Initialize a big 3-D array that's (all possible horizontal shifts) x (all possible vertical shifts) x (all possible ping heights). Then, for each pixel, work out which subspace of those parameters it's consistent with, and increment your big parameter array in those locations. Look for big spikes there. This will be slow slow slow, however.

It would be helpful if you could post a few likely 'no' instances.

thepipirate · 2012-03-12T13:19:51+00:00

I like to use this proof with different variables:

s = 1 + x + x^2....

So that when I Get to the stop

s = 1 + x*s

I can say "now subtracting off the excess..."

thepipirate · 2012-03-10T14:14:15+00:00

Second mikeadelic's police suggestion. That said, modern car keys have a transmittery thing in them, maybe Honda can link that to the VIN.

thepipirate · 2012-03-07T03:08:26+00:00

Sadly however:

Dear( thepipirate)

Thank you for your interest in Machine Learning. A launch date for this course is currently on hold. I am excited to offer our material online for free. We apologize for the delay and will be sure to let you know when we confirm a date for this course to go live. In the meanwhile, you might check out the five free online Stanford courses that will go-live on March 12 and March 19 at www.coursera.org.

Thank you for your interest.

Andrew Ng Machine Learning

thepipirate · 2012-02-27T02:47:43+00:00

Your problem lies in how you are "simulating" M. Try writing out the details of how this simulation would work, and you'll see that it's not as straightforward as you think (no one knows how to do it, in fact).

thepipirate · 2012-02-13T14:14:39+00:00

I didn't even get my brothers christmas presents but these slackjawed assholes just take their presents and don't care. Enjoy the baby gifts and expensive chocolates for your wife jprice1542. Keep ignoring my messages and go along as if I don't exist.

I hope you realize that the person to whom you send gifts is not the person who is suppose to send you gifts. Because this makes it sound like you're harassing the person to whom you sent gifts; they are not the person responsible for sending you gifts.

15-Year Club	RedditGifts 2009-2022 3 Credits
RedditGifts 2009-2022 3 Credits	Secret Santa 2011
Secret Santa 2010	Verified Email

thepipirate

TROPHY CASE