Search found 70 matches

by Quan
Fri Jul 03, 2009 2:11 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0394: "Kilobyte"
Replies: 138
Views: 36481

Re: "Kilobyte" Discussion

I happen to have implemented the XKCD standard for file size units in KDE (http://pastebin.ca/1482983). Thought I'd share the patch here, for those of you who are tired of the IEC standard KDE currently uses. And it's only a -7.7i KiB patch. (For best results, apply to KDE 4.3 or 4.4.) Is that Corr...
by Quan
Tue Mar 11, 2008 8:13 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0394: "Kilobyte"
Replies: 138
Views: 36481

Re: "Kilobyte" Discussion

My prof would always say "it's a lie. But it's a good lie; it makes life happier for us. :) " We consider electricity to flow from + to - because it makes the math easier in that field. Similarly, considering k to be 2 10 has made the math easier for some fields of computers. I think ambi...
by Quan
Tue Mar 11, 2008 1:29 am UTC
Forum: Individual XKCD Comic Threads
Topic: 0394: "Kilobyte"
Replies: 138
Views: 36481

Re: "Kilobyte" Discussion

I totally agree... I grew up without that silly sounding "kibi mibi" etc crap, it was understood that it was 1024 and not 1000... The only reason I can think of for people wanting to change it is because hard drive companies realized at some point that if they used 1000 bytes in a kilobyt...
by Quan
Mon Mar 10, 2008 10:09 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0394: "Kilobyte"
Replies: 138
Views: 36481

Re: "Kilobyte" Discussion

Unfortunately that is not consistent with SI prefixes , some of which predate "computer world" by a couple hundred years. The bottom line is that kilobyte is ambiguous whereas kibibyte isn't. Kilobytes and Megabytes weren't ambiguous until some bastards started intentionally misinterpreti...
by Quan
Mon Mar 10, 2008 6:45 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0394: "Kilobyte"
Replies: 138
Views: 36481

Re: "Kilobyte" Discussion

DeadCatX2 wrote:
Quan wrote:KB = Kelvin-Byte

The well known unit of heat information :D

Is this unit used to measure the intensity of a flame war?


Strangely makes sense, given a constant co-efficient of heat information for a thread, as heat goes up due to more flaming, information goes down.
by Quan
Mon Mar 10, 2008 5:54 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0394: "Kilobyte"
Replies: 138
Views: 36481

Re: "Kilobyte" Discussion

Look, people. I don't care about what "standard" notation for kilo/mega/etc are. This is computer world! See, as an engineer I'd rather follow IEEE (1541) and IEC (60027) standards than some convention. (incidentally, JEDEC confuses things by having their own definition of KB, MB and GB f...
by Quan
Mon Mar 10, 2008 3:31 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0394: "Kilobyte"
Replies: 138
Views: 36481

Re: Data rates

As for a solution to base-ten and base-two: KB 2 vs. KB 10 . Simple and not confusing, though if you want to churn out the pedants then KB 2 by analogy would have to be 8 bytes, not 1024 bytes, and then we're back at confusing. (Cookies to the person who figures out why and doesn't trip over their ...
by Quan
Mon Mar 10, 2008 2:52 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0394: "Kilobyte"
Replies: 138
Views: 36481

Re: "Kilobyte" Discussion

I've actually been doing a lot of reading in to this recently because I've been trying to convince Firefox to change their notation. Under the European Harmonisation Document and the new up and coming ISO 80000, if we're to be technical about things: KB = Kelvin-Byte kB = kilobyte (10^3 bytes) KiB =...
by Quan
Sat Dec 01, 2007 11:41 pm UTC
Forum: Mathematics
Topic: Distance from Sqrt(x) to .5x
Replies: 9
Views: 1790

Re: Distance from Sqrt(x) to .5x

Sqrt(x) is only an integer when x is a square number, x/2 is only an integer when x is even, go figure.

(Though it takes a bit more to prove that Sqrt(x) - x/2 is only an integer when both Sqrt(x) and x/2 is an integer).
by Quan
Fri Nov 30, 2007 7:57 am UTC
Forum: Mathematics
Topic: Have you ever used the values for e or pi as a password?
Replies: 44
Views: 4856

Re: Have you ever used the values for e or pi as a password?

When I need a 4 digit pin I find that 1729 is such a wonderful number to use (smallest number expressible as the sum of 2 positive cubes 2 different ways).
by Quan
Thu Nov 29, 2007 4:24 pm UTC
Forum: Mathematics
Topic: Hilbert space and stuff...
Replies: 6
Views: 1170

Re: Hilbert space and stuff...

Thanks a lot guys. The girl attempting the question is actually doing a statistics course and gave me the cauchy-schwarz inequality in terms of an expected value inequality (but I have a fair deal of familiarity with the cauchy-schwarz inequality).
by Quan
Thu Nov 29, 2007 3:30 am UTC
Forum: Mathematics
Topic: Hilbert space and stuff...
Replies: 6
Views: 1170

Hilbert space and stuff...

A friend of mine who is still doing a maths course (I graduated this year) asked me this question because I'm supposed to be the Algebra expert in my group of friends: "How do you prove that Hilbert space H2(T) is closed under addition and scalar multiplication using the cauchy-schwarz inequali...
by Quan
Wed Nov 07, 2007 1:51 pm UTC
Forum: Mathematics
Topic: Math Websites
Replies: 125
Views: 162031

Re: Great Math Site

That's quite cool.

In terms of forum help, I almost always find myself on the maths subsection of http://www.physicsforums.com/ - again it has integrated TeX in to the forum, so really easy to write up problems you may have.
by Quan
Wed Oct 31, 2007 1:08 pm UTC
Forum: Mathematics
Topic: 1000!
Replies: 13
Views: 5626

Re: 1000!

antonfire confused me - I don't want to even know what he was doing with numerology. Answer is 249 for reasons listed - that website is really good at explaining it. LoopQuantumGravity - where were you able to multiply that out and get all the numbers. btw - my first guess before I looked into it w...
by Quan
Wed Oct 17, 2007 2:56 am UTC
Forum: Hardware
Topic: Clock speed reached local maxima?
Replies: 46
Views: 9445

Re: Re:

This has nothing to do with desktop processors in specific though. In addition, many things are not coded parrallely, games are just coming a bit parallel. Your perception of the common workload of a desktop CPU may need some work you know. Spreadsheets that take several minutes to computer aren't ...
by Quan
Mon Oct 15, 2007 4:33 am UTC
Forum: Hardware
Topic: Clock speed reached local maxima?
Replies: 46
Views: 9445

Re:

I'd say over all it is much, much worse. A good number of interesting problems degrade to pointer chasing. Take for example maintaining a graph closure in a directed acyclic graph. Wider cores help you not, all that really matters is how fast you can chase pointers. Sure, most simple programs like,...
by Quan
Mon Oct 15, 2007 4:12 am UTC
Forum: Individual XKCD Comic Threads
Topic: 0329: "Turing Test"
Replies: 120
Views: 59932

Re: "Turing Test" Discussion

I hope people realize that xkcd seems to be a true html purist and it's actually the title text, the alt text only reads "Turing Test".

Pretty clever this week, but only made my smile a bit :)
by Quan
Thu Oct 04, 2007 7:46 pm UTC
Forum: Mathematics
Topic: Integral of (tan x)^0.5?
Replies: 20
Views: 12237

Re: Integral of (tan x)^0.5?

Well I managed to do it in the end, the trick appears to be in choosing a clever enough substitution and the rest falls in to place really. Choose: u = 1 + sqrt(2 tan(x)) Giving: du/dx = sec 2 (x)/sqrt(2 tan(x)) Play around with this for a bit and use the trig...
by Quan
Thu Oct 04, 2007 4:54 pm UTC
Forum: Mathematics
Topic: Integral of (tan x)^0.5?
Replies: 20
Views: 12237

Re: Integral of (tan x)^0.5?

PS @ Quan: LQG might have used less harsh language if you didn't respond to his post with "lol what?" and then acting as he doesn't have the faintest clue, when in fact it was quite clear, at least to me, that he was using a substitution. Fair enough, re-reading, I get what he's doing now...
by Quan
Thu Oct 04, 2007 4:00 pm UTC
Forum: Mathematics
Topic: Integral of (tan x)^0.5?
Replies: 20
Views: 12237

Re: Integral of (tan x)^0.5?

lol what? That's just differentiating it, and you missed a 1/2 in the first step. WTF is wrong with you? :| Yeah, sorry to be honest I have absolutely no idea what you're on about. ... u = tan(x) du = sec 2 (x) dx sqrt(tan(x)) dx = sqrt(u) / sec 2 (x) = ... I have no idea how you got that, mayb...
by Quan
Thu Oct 04, 2007 8:16 am UTC
Forum: Mathematics
Topic: Integral of (tan x)^0.5?
Replies: 20
Views: 12237

Re: Integral of (tan x)^0.5?

So yeah - I came across this question (find the integral of (tan x) 1/2 ) on the Cambridge maths department website, and it's been bugging me for ages. I tried integration by substitution, and ended up with an equation in two variables Wha? That doesn't make any sense. u = tan(x) du = sec 2 (x) dx ...
by Quan
Mon Oct 01, 2007 1:16 am UTC
Forum: Mathematics
Topic: solving with e and ln
Replies: 4
Views: 1412

Re: solving with e and ln

This can only really be solved by numerical analysis in terms of the stuff you've already learnt. It has 2 real solutions and an infinite number of complex solutions. Non-elementary functions can be used to solve it "exactly", but in a sense it's artificial, because they were pretty much i...
by Quan
Wed Sep 26, 2007 2:51 am UTC
Forum: Mathematics
Topic: Fraction
Replies: 41
Views: 5035

Re: Fraction

the fraction (1/9) is numerically equal to .111111111111111111111111111 etc. and as it goes (2/9) is equal to .2222222222222222222222222222. Seeing this I can not help but wonder whether 9/9 is .999999999999999999999999999 and we always round up because its infinitely small or is it 1. My math teac...
by Quan
Thu Sep 20, 2007 3:08 pm UTC
Forum: Mathematics
Topic: Word Numbers Puzzle
Replies: 33
Views: 4243

Well another problem is how you would write them, for example I'm not familiar with:

ninehundredelevenmillionsixhundredtenthousandthirtyfour for 911'610'034

In England we would write that as:
ninehundredandelevenmillionsixhundredandtenthousandthrityfour
by Quan
Thu Sep 20, 2007 2:51 am UTC
Forum: Logic Puzzles
Topic: Choose signs to make a complex series converge
Replies: 61
Views: 8499

Yeah, I was fairly impressed by the challenge and the simplicity of the solution once you were pointed in the right direction.

Nice problem :)
by Quan
Tue Sep 18, 2007 3:46 pm UTC
Forum: Logic Puzzles
Topic: Choose signs to make a complex series converge
Replies: 61
Views: 8499

Huh Yakk, I'm not sure your proof actually stands, I doubt it's logically valid to re-order like that. My proof doesn't require such a reorder. I'm also unconvinced without a reorder that you can make both of them converge to 0. But anyway, taking my proof a little further, you can look at the sum, ...
by Quan
Tue Sep 18, 2007 1:26 pm UTC
Forum: Logic Puzzles
Topic: Choose signs to make a complex series converge
Replies: 61
Views: 8499

While I was falling asleep last night, I had inspiration, but unfortunately wasn't able to post it as I actually fell asleep. It only leaves 1 case unproven: Let x_i and y_i be the components of z_i (= x_i + i*y_i) We know that: lim(i -> Infinity, x_i) = 0 and lim(i -> Infinity, y_i) = 0 Which impli...
by Quan
Mon Sep 17, 2007 4:26 pm UTC
Forum: Mathematics
Topic: The 6 Ns puzzle
Replies: 40
Views: 5205

ikerous wrote in the first post that you could use log and that it had to be base N. ikerous didn't state exactly what functions you could and couldn't use so i guess whether you could use -N or not is a matter of opinion. its just that in the problem we're told that we can only use N and no other ...
by Quan
Mon Sep 17, 2007 4:20 pm UTC
Forum: Logic Puzzles
Topic: Choose signs to make a complex series converge
Replies: 61
Views: 8499

So far I have a proof that there exists a sequence s_i (the -1 and 1 bit) such that Sum[s_i*x_i] converges. That's actually a direct consequence of the oscillating series property. The problem is getting a sequence that work for the xi and the yi. Oh really, I've not come across that one. Is there ...
by Quan
Mon Sep 17, 2007 4:03 pm UTC
Forum: Logic Puzzles
Topic: Choose signs to make a complex series converge
Replies: 61
Views: 8499

Right, I've made a little further work on this. I've been trying to tackle this by coming up with an appropriately good algorithm that chooses the signs s_i, to make sure that both x_i and y_i converge. Anyway, not really spoilerish, but some people might want to work out a few properties on their o...
by Quan
Mon Sep 17, 2007 3:32 pm UTC
Forum: Mathematics
Topic: The 6 Ns puzzle
Replies: 40
Views: 5205

in reply to the [(Arccos(-N/N))^((N/N) + (N/N))]=9 solution by gmedina, i don't think you can use -N (thats like 0-N or N*(-1) and you can't use 0 or -1). another way to do it would be ( log(N*N*N) )^( cos[cosN] + cos[cosN] ) where logN is base N and [a] is the integer part of a. -N seems more vali...
by Quan
Mon Sep 17, 2007 3:32 am UTC
Forum: Mathematics
Topic: Notations for matrices
Replies: 5
Views: 1297

Re: Notations for matrices

I'm typing up some proofs for linear algebra, and was wondering if there's a convention for writing My experience has varied on how I use them. Generally just use a capital letter like: Let A be an n x n matrix. Or sometimes A_(n,n). The identity matrix I've seen most frequently as I (or I_n for an...
by Quan
Mon Sep 17, 2007 2:58 am UTC
Forum: Coding
Topic: Funniest/Most Annoying Code Comments
Replies: 662
Views: 133554

String name; //Creates a String called name I see things like that ALL THE TIME in intro CS classes. i++; //add 1 to i /.... tons of other code, completely without comments ..../ int b = 0; //initialize b /.... tons of other code, completely without comments ..../ Haha, I read that the other way ar...
by Quan
Mon Sep 17, 2007 2:45 am UTC
Forum: Logic Puzzles
Topic: Choose signs to make a complex series converge
Replies: 61
Views: 8499

@Quan: You can do things like H 2 O, or a(b,c). I think I can show that the sum is bounded in modulus, but the argument bit isn't coming together it seems. Thanks, that's not too bad I guess, but I would just like the [sub]tags[/sub] to work and nested sub tags would make my day at the moment. I've...
by Quan
Sun Sep 16, 2007 11:45 pm UTC
Forum: Logic Puzzles
Topic: Choose signs to make a complex series converge
Replies: 61
Views: 8499

Only just seen this, cool problem :D I've been working on it for the last 20 mins or so, I've made quite a bit of progress on it (or at least I think so). I'll post my workings later tonight, I want to see if I can completely crack it before I give my workings away. The only problem though is my ans...
by Quan
Thu Sep 06, 2007 2:27 pm UTC
Forum: Mathematics
Topic: My mathematical speed bump
Replies: 36
Views: 5249

Everything eventually just sort of mixes together really easy. I think most people at your stage in understanding mathematics have the same problem, so many rules and some of them seem almost arbitrary, but then they go on to imply other things. I got taught mathematics in a different order, but I d...
by Quan
Thu Sep 06, 2007 2:18 pm UTC
Forum: Mathematics
Topic: Prime Number Formula; Looks a bit hokey.
Replies: 8
Views: 3885

http://mathworld.wolfram.com/PrimeFormulas.html

This is nothing special. And I've seen similar formula from that web page, but actually displayed in a much nicer way than that one.
by Quan
Thu Sep 06, 2007 2:11 pm UTC
Forum: Mathematics
Topic: Peer-review my mathy blog post!
Replies: 23
Views: 3272

Re: Peer-review my mathy blog post!

The real question you need to ask yourself, is there anything nature which is circle like at all? The circle is an abstract geometrical construct, really quite different in many respects to what the universe is made up off. Plenty of things look like circles. http://farm1.static.flickr.com/92/25181...
by Quan
Thu Sep 06, 2007 2:01 pm UTC
Forum: Logic Puzzles
Topic: Easy one for people with quantum computers
Replies: 17
Views: 3350

200 digits is pretty much impossible with a standard computer if you observe some basic rules, those rules imposing the general idea of these 2 points: 1. Not too close to the square root so that an algorithm working from the square root out can easily find them 2. Not too far apart so the smaller p...
by Quan
Thu Sep 06, 2007 2:26 am UTC
Forum: Logic Puzzles
Topic: Easy one for people with quantum computers
Replies: 17
Views: 3350

solution wrote:2


:) , factoring numbers like that is easy :P

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