Archive for the 'Uncategorized' Category

virtual economies

Old news that I never digested from about a year ago.

At first I wondered, well what exactly is being produced in game economies that are of productive value? Then, I thought, wait, what is being produced in real economies that are of productive value? Especially the “service sector.” Lots of things can be dismissed as having no productive value, but as long as there is demand, there is value, and where there is value, there is an economy waiting to develop. I guess that’s the first lesson.

Secondly, there is no way Anshe Chung would have been as successful in the real world without the virtual world existing. Not only would she not have pursued some of the, erm, career opportunities, let’s say, nor would she have been given the kind of opportunities such as real estate “development” to amass the starting capital as easily — most opportunities in the real world have been taken or have strong players already firmly entrenched. It puts a new kink in the argument of work vs. luck in terms of financial (or general) success in life, and it highlights the fine boundary between obeying social constraints vs. giving up on risk taking.

synthetic genome

all over the news today.

Scientists have built the first synthetic genome by stringing together 147 pages of letters representing the building blocks of DNA.

The researchers used yeast to stitch together four long strands of DNA into the genome of a bacterium called Mycoplasma genitalium. They said it’s more than an order of magnitude longer than any previous synthetic DNA creation. Leading synthetic biologists said with the new work, published Thursday in the journal Science, the first synthetic life could be just months away — if it hasn’t been created already.

“We consider this the second in our three-step process to create the first synthetic organism,” said J. Craig Venter, president of the J. Craig Venter Institute where scientists performed the study, on Thursday during a teleconference. “What remains now that we have this complete synthetic chromosome … is to boot this up in a cell.”

This is what they actually did. Looks like an interesting application of TAR cloning in yeast (another link) — normally used for sequence selection — which itself is a significant extension of the YAC toolset.

I guess small artificial genomes are a practical reality now, but TAR cloning is really the key here, allowing a less restrictive abstraction of the join operation to be implemented. Nice.

Dear Michael…

…the building manager,

I am getting sick from the formaldehyde and benezene fumes that are obviously emenating from the newly installed carpet. It smells like a freaking dry erase marker every time I breathe. My throat hurts, I have phlegm, my eyes water, and I got a headache. Look, I don’t want to get high on glue. You should have gotten a carpet installer (who will surely die from lung cancer) that aired the carpet out. Or left time to air the building out. How much is it worth to get everybody sick? Less than a week of rent? Think again…

resolving the St. Petersburg paradox

The St. Petersburg paradox is based on one of those gambling games where the usual model of using expected gain to decide whether to play the game gives a counter-intuitive result.

In the simplest of examples, you pay some entry fee to play the game, $1 is put in a pot by a counterparty, then a coin is repeatedly flipped and the pot is doubled on every coin flip by the counterparty, until “tail” comes up. You receive the money in the pot. The expected gain of this game is infinite, regardless of the initial entry fee. So it would seem that one should always play the game, regardless of the amount demanded as entry fee. But, as the article points out, “few of us would pay even $25 to enter such a game.”
(Read the article)

How to (maybe) get WordPress Stats to accept the API key

WordPress stats is a nice little filter for WordPress, one of those devious hidden image IP trackers. Unfortunately, getting it to accept the API key doesn’t always work (even if it works for Akismet without complaint).

You may keep getting

Enter your WordPress.com API key to link this blog to your WordPress.com account. Be sure to use your own API key! Using any other key will lock you out of your stats.

even if the API key is correct. or if you hard code the API key

An API Key is present in the source code but it did not work.

The WordPress.com Stats Plugin is not working because it needs to be linked to a
WordPress.com account.

I didn’t find a solution in any of the forums, so I looked at the stupid script some more. Basically it uses the API key to get a “blog_id” (database index, most likely) from WordPress.com and can’t find one. So I made up a blog_id in the code. That shut up the plug-in, but of course stats aren’t tracked.

Finally, I went to http://dashboard.wordpress.com, logged into the account, made a new garbage *.Wordpress.com blog, then a bit later took out the made-up blog_id from the code, de-activated and re-activated, and … everything works. The external blog shows in the “Global dashboard.” Also the real blog_id is returned from code. But, if I take out the hard coded API key, it stops working again.

This is definitely a WordPress.com problem with registering externally hosted blogs, so to make it work, hard code the API key, make sure there is at least one *.Wordpress.com blog, wait a little bit, then re-activate the stats plug in.

a little Gaussian problem

Here’s a problem I heard last month that I’ve been meaning to write up.

We know that if two random variables X and Y are jointly Gaussian, then X and Y are each Gaussian. The converse is not true, even if X and Y are uncorrelated — we have examples of this. What if one more condition is added?

Assume the following:

  1. X and Y each distributed as \(\mathcal{N}(0, 1)\)
  2. X and Y are uncorrelated
  3. X+Y is distributed as \(\mathcal{N}(0, 2)\)

Is X and Y jointly Gaussian or, equivalently, are X and Y independent (because uncorrelation implies independence for a pair of jointly Gaussian random variables)?

The necessary and sufficient condition for X and Y to be jointly Gaussian is for every non-trivial linear combination of X and Y to be Gaussian, so unless (3) somehow makes that true, X and Y would not be jointly Gaussian.
(Read the article)

credit card grace period

I just came across the topic of credit card grace period, and could not find a consistent answer on exactly how it is supposed to apply in more complex situations than a monthly full payment.

On the back of the bill, it is defined thusly

We accrue periodic finance charges on a transaction, fee, or finance charge from the date it is added to your daily balance until payment in full is received on your account. However, we do not charge periodic finance charges on new purchases billed during a billing cycle if we receive both payment of your New Balance on your current statement by the date and time your payment is due and also payment of your New Balance on your previous statement by the date and time your payment was due.

This still is fairly ambiguous. In order to find out how this works exactly, to the cent, I did a simple test and found out.
(Read the article)

8 perfect shuffles

It is said that 8 perfect shuffles of a standard deck of 52 cards results in an unshuffled deck. Why is that? Is it true only for 52 cards? What kind of shuffle is implied by this statement? Yesterday, we (high school math buddies) made pretty good sense of it.
(Read the article)

how to get NVTV tuner to work with MCE

This tuner card kind of sucks, but it is supposed to work with Windows Media Center Edition 2005.

It doesn’t work out of the box, though. The way to get it to work is to install the following:

  1. The driver, version 1.20.45, from nVidia
  2. Forceware Multimedia 3.62 from XFX (with these two, the card will work with nVidia provided applications)
  3. April 2006 update for MCE 2005 Rollup 2 (that makes the card work under MCE)

It still craps out occasionally, but it works. Image quality is pretty good.

Edit: Wow, a couple of days playing with MCE made me realize that PC’s these days can be woken from hibernation on schedule programmatically — that’s right, hibernation, not standby, and that’s right, by software, not via wake-on-hardware. I wonder how that happens… I gotta try this on an older PC now to see if it works there, too.

Calvin Broadus lost his mind

That according to the video and the comments here.

What’s more, this ridiculous song has an uncensored twin version… What.

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