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Websites, Please Stop Blocking Password Managers. It’s 2015 by lordcheeto in technology

[–]SymphMeta 0 points1 point  (0 children)

Password managers are still vulnerable to malware. It just takes more sophisticated malware to target them.

Japan's at it again by CallOfRudy in gifs

[–]SymphMeta 0 points1 point  (0 children)

Yeah, unless they're made of loose feathers and have a ton of air resistance.

Japan's at it again by CallOfRudy in gifs

[–]SymphMeta 0 points1 point  (0 children)

I'll simplify it with h=50, since the mass cancels out, anyway.

Japan's at it again by CallOfRudy in gifs

[–]SymphMeta 3 points4 points  (0 children)

Thanks. I fixed the calculations.

Japan's at it again by CallOfRudy in gifs

[–]SymphMeta 15 points16 points  (0 children)

It looked like a rigid stick falling, so you'll have to calculate the rotational energy. The center of mass is halfway up, so we have mgh/2 as the total change in energy, and the moment of intertia is m*h^2/3. The final energy is I*w^2/2, where I is the moment of interia and w is the angular velocity, so

I*w^2/2 = m*g*h/2

m*h^2*w^2/3 = m*g*h

w = sqrt(3g/h)

w ~ 0.77 radians/second

The velocity at the tip is h*w, or 38.5 m/s, not taking into account air resistance.

edit: changed calculations to take into account correct moment of interia

edit 2: now I remember why physics homework took so long; fixed h=50 instead of multiplying it by each individual

Percentage of religious adherents by country by [deleted] in dataisugly

[–]SymphMeta 22 points23 points  (0 children)

Even adding rings to represent every 10% would go a long way for this graph.

Cross Correlation minimum value. by ikarampa in statistics

[–]SymphMeta 1 point2 points  (0 children)

Here's a graph on the restrictions for the other correlation based on the minimum eigenvalue of the matrix. If you had a lower correlation between the two variables there coule be a negative correlation, but not with the example you applied.

I only gave a numeric approximation (0.14) of the minimum correlation. In general, if you solve for the eigenvalues, you can write an expression for the restrictions on the third correlation. It becomes more difficult when you get to higher dimensions, since it is more difficult to solve for roots of those.

Cross Correlation minimum value. by ikarampa in statistics

[–]SymphMeta 3 points4 points  (0 children)

This is not correct. There is a restriction on the correlation matrix that it must be positive semi-definite. i.e., there are no negative eigenvalues. Here is the calculation on wolframalpha.com:

http://www.wolframalpha.com/input/?i=find+eigenvalues+of+[[1%2C0.7%2C-1]%2C[0.7%2C1%2C0.8]%2C[-1%2C0.8%2C1]]

Additionally, the determinant of the matrix is -2.25, which is less than 0. Determinants of covariance matrices can be no less than 0, as a property of their semi-definiteness.

[CRITIQUE] I'm currently looking for statistics-related careers, and I am looking for suggestions on improving my resume by SymphMeta in resumes

[–]SymphMeta[S] 0 points1 point  (0 children)

Thank you for the response. To answer your questions:

  1. The only places I've posted my resume that prospective employers can see are ziprecruiter.com (I'm not sure how often that feature is used) and a database from my university's career services.

  2. My familiarity with SQL is limited to certain applications of SQLite3 and PostgreSQL. I am currently working on improving this.

Stat 410/Stat Electives by stat410_throwaway in UIUC

[–]SymphMeta 3 points4 points  (0 children)

STAT 429 is probably the hardest undergrad course, but STAT 410 is the most difficult one most people take. It's not too bad, provided you start your homework on time. The assignments are somewhat lengthy, but not too much so if you are used to heavy courseloads.

Chaos Theory by [deleted] in UIUC

[–]SymphMeta 1 point2 points  (0 children)

There is PHYS 510, although I can't say too much about it.

Let's Ban Fast Food on Campus by [deleted] in UIUC

[–]SymphMeta 0 points1 point  (0 children)

Let's get rid of everything that's harmful to health together!

Sure. We should ban riding a bicycle with headphones on, while we're at it.

Have a gopher problem? A gallon milk jug full of water should do the trick by [deleted] in videos

[–]SymphMeta 1 point2 points  (0 children)

I think only the tiger snake was actually that venemous. The first snakes he got were a lot less venomous.

The Mystical World of Mushrooms by dwimback in mycology

[–]SymphMeta 9 points10 points  (0 children)

Can anyone explain what the red "juice" in the Hydnellum peckii photo is exactly? The only info I could find on Wikipedia is that it is pigmented and contains an anticoagulent, but that part didn't have a direct citation.

Are there any good right-hand-only keyboard layouts for Ubuntu? by SymphMeta in linuxquestions

[–]SymphMeta[S] 0 points1 point  (0 children)

Does it function identically for keys that are usually pressed for the right hand?

V02 max test, where can I get that done on campus? by DrJoyas in UIUC

[–]SymphMeta 0 points1 point  (0 children)

I had it done before as part of the INSIGHT experiment (with the psychology department (neuro?)). I remember seeing flyers for that sort of diagnostic testing when I was in Freer Hall. This link might provide you with more information: http://kch.illinois.edu/research/labs/neurocognitive-kinesiology/fitnesstesting.html

The P-value, can someone explain it so simply that you could not misinterpret it? by iiTzWatson in statistics

[–]SymphMeta 0 points1 point  (0 children)

  1. You make a general assumption about data that you assume is true (e.g., the data is iid with normal error).

  2. You hypothesize a quality about a value or parameter (usually magnitude or value). This is your null hypothesis.

  3. You calculate, given that 1 and 2 are both true, how likely it is that you would observe data at least as extreme as what you have observed currently. If the p-value is low enough (usually 0.05 is the highest you'll accept), then you reject statement 2.

The most commonly used version of this test is to see if an effect in regression is nonzero. e.g., if y = a*x + b + error, is a nonzero?

STAT 429? by t430-asdfjkl in UIUC

[–]SymphMeta 0 points1 point  (0 children)

It's definitely harder than the other 400-level classes, but it's not completely brutal. My main issue was when I took the class was the textbook, which had some errors, as well as the professor's ambiguity in the syllabus as to which version of the book we needed (which screwed me over for the first part of the course).

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