They're Still Getting It Wrong

It is a well known fact that boys have a higher variance on high school math tests than girls. No one knows what causes this - maybe there are different social pressures on boys, maybe boys test differently, maybe boys are innately different. Anyways, the results of the latest study which, again, showed higher male variance are still being misreported:
26. Girls and boys now perform equally on standardized high school mathematics tests across North America, ending a gender gap that lasted for decades.

The source for this quote is the study I linked to, which showed that the extreme scores are more likely to be male's scores. The study showed major differences in the scores! Of the major media outlets, only the WSJ got it right the first time around. Of course the bad information was passed on.

What shocks me about all of the coverage is that no one has reported the differences between whites' scores and Asian-Americans' scores in the study. While the results from white Americans fell in line with previous results, namely that twice as many boys as girls were expected in the 99th percentile on math tests, this wasn't true for Asian-Americans. An Asian-American female was actually a hair more likely to be in the top percentile than an Asian-American male, though this fact didn't hold for the top five percent of scores. I haven't seen quantitative studies on differences in values across different racial groups, but from anecdotes and personal experience I think that Asian-Americans parents have fewer differences in expectations from daughters and sons. This is the first data (I've seen) which supports the variance difference being an environmental one. There wasn't enough data on any other group to make it into the study.


On Vacation until January 2

I'm going to take a blog vacation until January 2. I'm burned out and need a vacation from everything right now.

As a random aside, the critical Dutch phrase of the week is "praten over koetjes en kalfjes." This phrase is the Dutch equivalent of "shoot the breeze" or "shoot the $#!+," and literally means "to chat about little cows and little calves."

The Dutch word "koetje" is the diminutive form of "koe," or cow. The same is true of "kalfje" and "kalf." Diminutive words signify a smaller or more intimate form of a regular word, and in most languages these words have a common suffix. Common examples in English are doggy, baggy, piglet and duckling. The Dutch use the diminutive form extensively. I think Dutch speakers obsess over 'j'-based sounds such as je, pronounced "juh," much as Americans love the sounds of "eh" and "er".



Today I convinced myself that the central idea behind my PhD is not practical.



Life vs Securing Property

I'd never heard of Katko vs Briney, but the ruling is fascinating.

Near small-town Oskaloosa, Iowa, owners of an unused property created unmanned traps with shotguns to shoot any trespassers. The gun was aimed to injure the legs, but not kill. It was well known by neighbors, and also apparent on the property, that the property was unused.

A burglar who had previously broken into the house for antique jars came back to look for more antique jars. When the gun shot off part of his leg, he sued...and *won*. Apparently the right to life is more fundamental than the right to property; the court thought only defending the safety of an individual gave the right to risk another person's life.

I kid you not about the antique jars. Iowans are taught to use jars for everything, from jam to sinaasappelsap. Mmmmm, sinaasappelsap.



When I was in high school I used Photoshop at a web design job. I worked with an older graphics guy who taught me not only basic graphics techniques, but also random things, like how to create a fake photo with a man's head on a woman's body. He did this with one of my photographs, enlarging my nose and chin to enhance the effect. I showed this fake photo to my friends, all of whom thought it was hilarious. To impress them, I secretly put their heads on different bodies of women. When I showed them their "womanized" versions, they all freaked out. I asked them why, and they said it was cool when it wasn't their photograph.

Airbrushing isn't new, but I don't see the "behind the scenes" examples very often. While browsing around today, I came across an airbrush example I've seen a few times. The link below contains a women in a bikini but no nudity, so it might be NSFW depending on your workplace. You'll need to mouse-over the photo for the effect.


Another great example which is definitely safe for work is at:


Sometimes I wonder if most humans are like my friends in high school, only we don't know that the media plays tricks on us all day long. Or maybe we're supposed to know?

PS My face on a woman's body is hotter than 20% of women, according to HotOrNot.com. I don't think people were rating the face, though. No, I'm not going to post the photograph here. Yes, I'll close the comments on this post if I have to.


Is Cash an Incentive?

Roland Fryer claims cash motivates students. His grade payment program has expanded from NYC last year to to Chicago, DC, and NYC this year.

Dan Ariely claims monetary incentives could easily be counter-productive. He walks a fine line by making only simple assertions in the article, but the article implies big cash bonuses to be harmful.


Technology to Solve One of Woman's Oldest Problems?

The lids lifted up when I approached. If I stood in front of one, it took a guess at my gender and lifted up the seat as well.

The BBC on how toilets are going to solve the classic "seat down" dilemma, improve our lives, and also bring world peace.



That is the Taj Mahal Hotel about two and a half years ago when I visited. I never thought a photo with an overcast sky could be beautiful, but now I think it will be for a while.

It is very strange seeing places I've actually been in the news as terrorist targets. New York City was a distant land during the World Trade Center attacks in 2001. But I walked through the Taj Mahal Hotel when I was in Mumbai. My hopes and thoughts are with all of the victims.

Europeans: No to Pie

Now that the election season is finally over (okay, well, not in MN), it is time to look forward to future candidates. With the recent murmurs of a pie run for President, I though I'd talk a bit about European views on pie. Europeans prefer desserts that can take the heat, and though pie shows promise its distasteful actions leave Europeans hungry for something else.

First, most Europeans consider pie too inexperienced to lead. Do you know how old most desserts are? Modern pudding, for example, is a highly refined beast. Pudding started as a custard in Roman times, experimented with sausage meat in the 17th and 18th century century, replaced its easily-spoiled egg components with modern chemicals during the great push west, and finally became the sweet dish we know today just as pie came onto the scene. Chocolate, too, has also undergone a defining journey. As a drink chocolate was too wishy-washy on issues, and has now solidified its stance against quaffing as a primary means of consumption. Looking at these histories, Europeans ask themselves, "Where is pie's history? How do we know that it isn't just the crust that is flaky"?

Thsee long histories have also given these recipes a chance to work across boundaries. The international crisis in Iceland gave British pie a chance to rise on the international scene. What do pie do? Pie used terrorism laws to keep Icelandic food in the British Isles! Pie's clumsy maneuvers have allowed blini to further its questionable motives. Europeans know that chocolate would never take such a stance; Nordic milk helps create some of the finest chocolate.

Blini has already shown up on the cover of an Icelandic recipe book. Or is that a dinosaur in the right photo? I can't really tell, I need glasses.

Finally, Europeans fear pie's strong ties to the dark, corporate side of America. Pie and corn starch's on-going attempts at alignment show that pie isn't the grass roots hero it claims to be. Furthermore, pie's relationships with cloying sugar and cream cause grave concern in the European community. Europeans often look at an American pie and exclaim, "Is there any healthy ingredient in that abomination? Why does pie drown out the fruit with sugar? No wonder Americans are so fat".

While pie faces strong opposition overseas, I don't think this will affect American opinion in the next election. With over a billion dollars spent in the last campaign, pie's ability to raise funds could lead to a decisive advantage. At least with the kitchen demographic.


Happy Thanksgiving

Nobody really celebrates Thanksgiving over here, but I decided to find something American that I could be thankful for. And find something I did.

America, thank you for exporting your original, canned hot dog recipe. Tonight I'm going to have a TV dinner with these guys and some Coke, eating them while watching the Simpsons episode where they reverse the toilet flow in Australia. And I'm going to try not to cry, but I don't think I'm going to succeed.

God bless America.


On the Rationality of Contracts

If a punishment of breaking a contract was death, would a rational person ever enter into such a contract? I've been thinking about this recently because an Islamic tenet is that apostasy's punishment is death.

The US social contract has death as an available punishment; certain criminal actions in Texas could lead to your death. All US citizens live under this contract. One could argue, however, that this punishment is a feature of the natural contract between all people and further restrictions on the right of life is not rational. I mean Locke's "state of nature" contract when I say natural contract.

Civics Quiz

I got 31 out of the 33 questions correct. I missed the origin of the "wall of separation" quote, and the definition of the Puritans. Supposedly elected officials and Americans average under 50% correct. I actually don't think elected officials would miss so many questions - I'll believe it when I see it with my own eyes.


Follow-up to Charging by Weight

Flying in Canada, you can get another seat for free...but you have to qualify as obese.

In a previous post I guessed about how much people pay for fuel. I estimated that about 5% of a ticket's cost on long-distance, crowded flights is the weight of a person and his/her luggage.

In case the previous post wasn't clear, I think that airlines should be allowed to charge a passenger for his/her weight and baggage's weight. Thus I disagree with the Canadian ruling, though I can think of a few arguments for it.

Knowledge Export

As a kennismigrant (knowledge immigrant), I appreciate some pieces of knowledge more than others. Such as the European style of eating a kiwi. In these busy days I wouldn't normally have time to eat a kiwi, much less prepare a blog post. Luckily, however, Europeans love solving multiple problems with a single solution. Looking for a solution that is easy, classy, filling, delicious, *and* blog-postable? Carve out a kiwi, yo.

Several kiwis were harmed in the creation of these photographs. Feel free to direct any complaints here.


Noise in SPADs

Today I'm going to continue my post from two weeks ago and talk about noise in SPADs.

As I discussed in my previous post, a SPAD consists of a fast, positive feedback system in conjunction with a slow, negative feedback system. The positive feedback system detects generated electrons, whether they're created by tunneling electrons, traps, thermal electrons, or photons. Since we're focusing on photons, the other types of generated electrons are noise.

If you don't know much about silicon, you probably don't know what a trap is. Standard silicon consists of a repeating pattern of atoms. We need to implant ions into this repeating pattern so we create the properties we need - raise the voltage here and it goes down over there, etc. However, implanting these ions can damage silicon's structure so that the atoms no longer form a neat pattern. When atoms don't form a neat pattern, electrons interact differently with the damaged part of the lattice. Sometimes electrons get stuck in these damaged parts for a bit of time, hence the term "trap". When the electrons finally leave the trap, they can cause an avalanche.

The most prevalent location of traps is at the interface between the silicon and the insulating silicon oxide. Every modern SPAD I've seen buries the region in which the avalanche occurs, the multiplication region. Burying the multiplication region keeps it away from most of the traps and "trap-generated" electrons.

Another source of noise is tunneling. Tunneling is a phenomenon that requires knowledge of quantum mechanics, and I don't think I can explain it well in a paragraph or two. A good one sentence description of tunneling might be, "The laws of nature do not stop electrons from jumping over barriers of any size, although the odds decrease with different barriers." The main way to control tunneling is to change the properties of the barriers between different regions of the chip, specifically the doping of the different implants we add into the silicon.

There is another source of noise I didn't mention called crosstalk. Crosstalk is ostensibly named because improperly-wired phone circuits can pick up pieces of other phone conversations, or leak portions of your phone conversations. SPAD crosstalk is the phenomenon of one detector's firing causing the unwanted firing of another detector. Crosstalk can be standard electrical crosstalk, which is uncommon in SPADs, or optical. Optical crosstalk is pretty cool - it turns out that stray electrons can create photons much as photons create electrons. During the middle of an avalanche a SPAD gives off a lot of photons, and these photons might accidentally cause another detector's firing. Optical crosstalk isn't a severe issue in most SPADs, but it varies from environment to environment.

Though optical crosstalk can increase the noise from SPADs, the created photons do have one advantage. Since an avalanching SPAD gives off photons in the multiplication region, taking a long exposure picture of a SPAD allows us to see whether the multiplication region has the shape we expect. If our silicon implants go poorly, we won't see a uniform multiplication region.

I hope you enjoyed a discussion of the source of noise in SPADs. If this seems boring, keep in mind that we're detecting single photons here! Over the next few weeks I'll start to discuss some additional properties of SPADs, and eventually I'll get to the point where I start comparing them to CCD or CMOS image sensors.

PS Blogspot's dictionary claims that avalanching isn't a word, but it doesn't contain truthiness either. Very suspect.


Geographical Variation in Sensitivity to Blue Light

We have a blue laser in one of our setup rooms, and my Japanese colleague's eyes appear to be more sensitive to blue light than my own. We pointed the laser at the wall and pointed to where we thought the light ended, and the two European descendants (Swiss and American) both saw less blue light than the non-Europeans (Iranian and Japanese). Has anyone heard of cross-regional studies in sensitivity to blue light? Neither I nor my Swiss colleague had heard this before, but my Japanese colleague said this was (somewhat) common knowledge.

My head is spinning thinking that people from different regions see all of art differently. I wonder if this has an effect on designing web logos? Would we expect to see different shades in different regions?

EDIT: Since laser light contains only specific frequencies, someone suggested that we might be most sensitive to different frequencies of light. This is known to occur - there are variations in what frequencies people are most sensitive to. Some studies even suggest that a faction of women have four different kinds of cones, rather than three.


So Long, First Web-site

I think the first, useful web-site I completely created was a political web-site for Swati Dandekar. Swati won a seat in the 2002 Iowa state house of representatives election. This year she ran for an Iowa state senate seat and won. Congratulations Swati!

Unfortunately they had to do away with my 1st symphony for an updated web page that is clearly *not* the work of a high-school student. Maybe they could have kept the animated state logo and "Excellence for Office" gif? That was genius. Seriously. How many web-sites can pull off an animated gif? I should have gone into advertising.

(I'd like to point out that the way-back machine doesn't cache the roll-overs, so those image roll-overs were not only fashionable at the time, they were also working.)


...where I do talk about politics...

Why don't random European girls kiss me?

...where I don't write about government...

I was going to write about government for my regular Friday post, but with all the politics lately I decided this would be a bad idea. So instead I'm going to share a lighter subject, which is a little family history about how my two paternal grandparents met. I know I've told a few "Oog Robot" readers this story, but this is my favorite family story and deserves a repeat or two.

My grandmother was a city girl from Pennsylvania. She was a chemical engineer who applied to the Heinz company for an internship over one of her summers. The Heinz company decided she was some combo of awesome and fearsome, because they decided to send her to be a chemical engineer in one of their ketchup factories. If she didn't like the acid levels in the ketchup, the plant's ketchup wasn't going out the door. Except the ketchup factory was in Muscatine, Iowa (i.e. middle-of-nowhere-small-town, middle-of-nowhere-state).

My grandpa was home for a summer from the University of Iowa. He met my grandma and worked up the courage to ask her to a movie, but she turned him down with something like, "I've got to wash my hair." Anyways, my grandpa decided to go to the movies anyways with a few of his buddies...and he ran into my future grandmother, with another boy of course.

After the movie, things must not have gone too well with the other boy because my grandma was waiting for the bus or a taxi when my grandpa ran into her. He offered her a ride home, and the rest is history. I don't know how my grandpa convinced her to move from Pennsylvania to Muscatine, IA. But I appreciate this now.

Grandpa and Grandma were two of the coolest people I know. My grandpa was a farmer and a lawyer! He'd get up before dawn, feed some cows, and then go work out some intricate legal arguments at work. He believed people should always have two jobs, in case one didn't work out. My grandma is probably responsible for sending me to MIT. She gave me a subscription to MIT's Technology Review, which sparked my interest in the school. I might have discovered MIT later, but who knows? I think I probably would have ended up at Iowa State University if she had not given me the TR subscription, and I would be a very different person.

Anyways, my grandpa passed away when I was in 5th grade, and my grandma died when I was a freshmen in high school. I wish I'd been able to get to know them better.


Tie in Iowa County

Iowa County, a county in (unsurprisingly) Iowa, had as many blue votes as red votes.
Obama: 4,173
McCain: 4,173
"Other": 125

I thought this would be a rare event until I messed around with a few numbers. If you assume that voters are independent and equally likely to vote for one of two candidates, the chance of an 8,000 person county being equally divided is almost 1%. With fewer people in a county, the odds increase. Assuming 100 counties with fewer than 8,000 people, one expects at least one county in the country to evenly split the vote.

Those are some pretty big assumptions, though. The odds are very sensitive to how split the voters are, so if one candidate has odds of 51% and the other 49%, then the probability for such a county drops to around 0.1%. If you assume 52% odds for one candidate, then we're down to 0.001%. I used the handy binomial calculator from Vassar to crunch the numbers. Also, I do not think that county size and vote color are independent; I would guess that small counties tend to vote red.

A quick, non-exhaustive search shows there were a few other counties that came close:
KY's Bath County: 24
MN's Murray County: 25
MN's Aitkin County: 10
MO's Washington County: 9 (EDIT: added later)

I couldn't find systematic county data to look at, so I might have missed counties that were closer or even tied. The data above (having a few counties in the sub-25 range) suggests around a 20% chance of a tie during an election in which a democrat is slightly ahead.


Wikipedia Antics

Head over to the front page of Wikipedia. Reload the page a few times (done by hitting f5 in IE or Firefox). Way to be unbiased, Wikipedia. Now if only the sides of the pictures flipped, too.

(this post will probably only work today)


American Elections

I cannot wait until I don't have to answer questions about American elections. Mostly I clarify confusion about why such a large percentage of Americans support John McCain. People are very confused when I explain that I would have voted for McCain in 2000 if I had the chance. I was under 18 at the time, and I'm still confused why 16 year-olds are not allowed to vote.


Basics of Single Photon Avalanche Diodes

As you may or may not know, I work with single photon avalanche diodes (SPADs), sometimes referred to as detectors instead of diodes. I'm going to give a high level overview of SPADs in this post - why we care and how they work.

First, why do we care about single photons? One reason you should care is quantum computing. Most computing today relies on classical electronics, and uses assumptions which are starting to be not so valid. For example, you might know that CPU makers are no longer focusing on speeding up their processors much more, and instead are focusing on placing more and more "cores" onto chips or lowering power consumption. In the past, shrinking the device size has allowed CPU makers to speed up their processors. Everyone agrees that to speed up processors, we're going to need to find other ways of performing computing. Another way is quantum computing, which does not rely on the same set of assumptions as classical computing, but requires different technology. One applicable technology is accurate detection of single photons. My group works with other applications of these detectors, including radiation hardened detectors, distance sensors, and some mysterious stuff I can't talk about.

The distance sensor application is particularly cool. By measuring the flight time from the laser to the environment to the photon detector we can actually get distance accurate to less than a mm in a second. Keep in mind that the speed of light is 3 * 10^8 meters per second, or 300,000,000,000 mm/s, meaning we need to have accuracy in the picoseconds. The current accuracy is in the 100s of picoseconds, but multiple measurement within the allotted second increase accuracy. If you're really interested in the topic you can look for the 2008 ISSCC paper "A 128x128 Single-Photon Imager with on-Chip Column-Level 97ps 10bit Time-to-Digital-Converter Array".

Short aside: a 4 GHz computer has a clock period of 250 picoseconds. Light and information only travels about 7.5 cm in 250 picoseconds! With all the random stuff in your processor slowing down signals, you cannot route signals across the entire processor and have this information communicated in one clock cycle.

Anyways, back to SPADs. I'm going to explain the notion of an avalanche first, and then I'll explain how an avalanche applies to SPADs. Free electrons are just bouncing around in the air. When we apply an electric field, the fields interacts with the electrics and causes them to move faster in the field's direction. If we make the field strong enough, an electron might gain enough speed to strip an electron or two off an atom during a collision. The original electron and the stripped atoms again start to acquire speed, and when these electrons hit another set of atoms we expect to have more than four electrons. Another round and we expect to have more than eight electrons (see footnote 1 for details). This process is exponential, so in a short amount of time we'll expect to have millions of electrons that are moving very fast. When an event causes more of the same type of event to occur, this is known as positive feedback.

The basic idea of a SPAD couples the avalanche's fast positive feedback system with a slow negative feedback system to quench the avalanche. The key component to an avalanche diode is, surprise, the electrical diode. I don't want to go to much into how a diode works, but the important point is that putting a large, negative voltage across most electrical diodes (not a standard operating condition) causes a very strong electrical field to build up in part of the diode. If the voltage increases enough, we can get avalanches. When a photon interacts with an atom in the diode, the photon can strip free an electron. Thus a single photon creates a single electron, which can cause an avalanche, which would start to move a lot of current. We currently have about a 30% probability that a photon causes an avalanche (see footnote 1).

I can hear a few people protest, "But wait! There is ambient thermal energy which can also create electrons - don't these electrons cause avalanches?" Avalanches occur in the absence of light. Aside from thermal electrons, tunneling electrons also cause photon-less avalanches. These rate of these non-photon avalanches is the dark count rate (DCR) of an avalanche diode. The DCR obscures the signal, and we usually want to keep the DCR as low as possible. (see footnote 2)

Now that we have a lot of electrons moving (and electrical current flowing), how do we quench the avalanche? And what about detection? Placing a component called a resistor in series with the diode causes the current to flow through the resistor, raising the voltage across the resistor, lowering the voltage / electric field across the diode, and quenching the avalanche. We can observe the voltage at the resistor for spikes to detect avalanches. This is the slower negative feedback system I discussed.

There are lots of details I've omitted, but I hope you found my explanation useful. If you have questions, please leave them in the comments - I'll make sure I answer them.

Footnote 1: The interactions of the electrons with the atoms are random, so sometimes an electron only picks up a little speed before it hits an atom, sometime an electron picks up a lot of speed. Thus we can only talk about avalanches in the expected sense, saying "we expect to see X".

Footnote 2: Some people actually like a high DCR. It turns out truly random information is difficult to create. Dark avalanches, to the best of our knowledge, are truly random event (based on quantum interactions). Some people are working to create "random information generators" based on these detectors.


Post Pushed Back to Saturday

I have a final tomorrow morning so I'm pushing back my regularly scheduled post to Saturday. Until then you can rest easy knowing that the Dutch word for glove is "Handschoen".


Taxes Across Countries

The Organization for Economic Co-operation & Development (OECD) has released their annual report of taxes across countries. This year's data comes from 2006. Quick hits of average tax rates:

Mexico - 21%
US - 28%
Switzerland - 30%
Netherlands - 39%
Denmark - 49%

The brief is mostly European countries, ostensibly due to information availability.

I'm not looking forward to taxes next year, though supposedly I can apply to be tax-free in Holland the first three years I'm here.


(Roughly) Half of a Plane Ticket's Cost is Fuel

(there is an edit at the bottom of this post)

Due to some commentary on my last post, I decided to calculate how much you pay for fuel when you fly.

While kilos lifted and moved might be a small fraction of the total cost, it is still a fraction of the total cost. But what fraction?

Wikipedia says that *new* aircraft consume about 3 L / 100 km for only the passenger, not the luggage. Thus, per passenger, we're looking at 30 cc per km. Let's assume an average weight of 72 kg per passenger. Now we've got .42 cc / (km * kg). Gas prices are tough, because they're over $6 in Europe but only $2.50 in the states (airplane fuel costs nearly the same amount as car fuel, I don't have a great source on this). We'll assume gas is $3.78 a gallon, or 1$ for 10^-3 cc. So fuel is .42 cc / (km * kg) * 1 $ / (10^3 cc), so the conversion between dollars and km * kg is:

4.2 * 10^-4 dollars / (km * kg).

NYC is about 6,000 km from Amsterdam. 20 kg * 6,000 km * 4.2 * 10^-4 $ / (km * kg) comes to (drum roll):

50$ (EDIT: This is overstated by a factor of 10 - see below)

I looked at ticket prices for a flight from NYC to Amsterdam in February. With tax, a round trip ticket is about $800. For 80 kg of load, that is $200 each way, or $400. Fuel is about *half* the price of your ticket. This meshes with what was presented in our 6.UAT lecture on estimation...wow, that class actually came in handy for something.

One further assumption is required for the above to be valid: burned fuel must scale linearly with weight. We'll leave that one to the reader.

If fuel is indeed half the cost of a plane ticket, why does a 60 kg person with 5 kg of luggage pay the same $800 as an 80 kg person with 20 kg of luggage? The 65 kg of weight should pay less than $700.

And why does going to a XXX2 matinee cost the same amount as going to see The Dark Knight?

EDIT: loyal reader asc has pointed out that the fuel efficiency should include the plane's weight. If we look at the weight of an A380, we see the plane is about 275,000 kg when empty. 555 passengers at 90 kg apiece (72 kg weight plus 18 kg luggage) weigh 50,000 kg. Including other weight (seats, fuel, etc.), it seems reasonable that the passengers account for at least 10% of the total weight. If we assume 50% of ticket price is fuel, we're looking at more than 5% of a ticket's price being fuel to move you and your stuff. Thus we're down to the Hamilton range:

Though this is hazy economics range, I maintain airlines could still turn a profit here. We know that $15 changes in ticket price have large effects on consumer behavior. Smaller customers would be more likely to fly an airline that charged by gross weight, meaning a charge-per-weight airline would be taking the smaller customers from its competitors, and leaving them with the larger (more expensive) ones. Furthermore, I haven't even mentioned non-financial incentives. Wouldn't you be happy flying an airline that charged people based on the amount of fuel they burn?

Airlines and Movie Theaters

A few days ago Continental Airlines announced it would be shrinking its luggage allowance. While perusing this article, I thought of pricing at movie theaters.

Movie theaters price matinee tickets uniformly - if you go to a movie on a Friday night, you'll shell out $10 whether you're seeing The Dark Knight or XXX2. I'd consider seeing XXX2 if it cost less than The Dark Knight.

For airlines, you pay the same amount no matter your weight. I can think of a few girls that pay the same for a plane ticket as I do, even though they are at least 20 kilograms lighter than I am (with luggage, though, we probably cost the same to fly).

Why do you think movie theaters and airlines have flat pricing? A "pay per kilo" model would probably insult airline's overweight customers, though $15 must make a big difference when we're booking plane fare. I'm waiting for the "pay per kilo" airline. You'd buy a ticket with a weight allowance, and pay extra if you and your luggage (together) are over this weight.

Daylight Savings Time

Clocks moved an hour back today for everyone in the Netherlands. In the states this happens next week. WTF?


Border Issues

If you think the U.S. has border issues, imagine what the Netherlands and Belgium have to go through in Baarle-Nassau (google maps link).

In other news, southern towns in the Netherlands are having trouble with the tourist influx caused by the cannabis shops. The Dutch have a very tolerant view of drugs, but no tolerance for violence. An excerpt from Cop in the Hood:

I saw a police officer give an addict back his heroin when the addict was released after a night in jail for some petty crime. I expressed my amazement to the officer that he could give illegal drugs back to a criminal. He explained to me that as soon as the man ran out of heroin, he would break into a car to get money to buy his next hit. It made no sense to the police officer to hasten the addict’s next criminal act by taking away his drugs. I asked about sending the wrong message. The police officer said his message was stop breaking into cars.


More Bicycles

This is going to be a photo-centered post about bicycles. I'd read about Holland and Denmark having a lot of bicycles, but I had not seen images that convinced me this was the case. I'm going to show some infrastructure and pictures to convince you about the pervasiveness of bicycles in Holland. But first I'm going to go over a standard Dutch bicycle.

I bought a bicycle last weekend:

My bicycle is a standard Dutch bicycle. There are a few things you'll notice are different than an American bicycle. First of all, there is the luggage rack over the rear tire. All standard bicycles in Holland have these racks. When I say standard, I mean bicycles which aren't racing or folding bicycles. Second, the handlebars are curved. Very few bicycles have straight handlebars. I'd guess it is a style thing, though I'm saying this simply because I understand neither style nor curved handlebars so I'm lumping the two together. The lock is also a bit different, as the next three photos show. The first photo is a picture of the left side - there is a key that cannot be removed unless you turn the metal bar on the right side. The bar goes into the back wheel. You can see the bar in second and third photos below.

Next to my bicycle this morning was another type of Dutch bicycle:

While buying my bike, I asked the store clerk about why some bikes have the curved metal like this one. He said it is a girl's model (I swear I've seen guys riding bikes like these). He didn't have a good reason was it is a girl's model, but it does look more stylish than a standard bicycle.

As I wrote in my post on my apartment, the building has bicycle sheds. Here is a photo of one floor's bicycle shed:

There is also a general area for parking bicycles in the apartment building:

My workplace actually has an underground bicycle parking lot! Rijwielingang, the sign over the entrace, literally means "row wheel entrance". Rijwiel, or "row wheel", is one of the three common Dutch words for a bicycle - the other two are fiets and tweewieler. "Ingang" means entrance. Google Translate only bats about .750 with Dutch.

To give you an idea of how common bicycle commuting is, here are some other "parking lots". The first picture was taken outside my building at about 5 pm. Parking underground is a bit of a hassle, as you have to pedal up the tunnel - a lot of people park outside and risk the rain. The second shot was taken at the library (bibliotheek). The third shot shows one of five or six parking lots near the train station.

Finally, to give you an idea of the infrastructure I've been talking about, I took a picture of the bicycle "light" at an intersection. You can see that bicycles, like cars, have to wait at a stoplight when crossing an intersection. There is a push button for requesting a crossing. The bicycle request button has a feedback light, but the pedestrian button does not.

As for roads, you can see above that bicycles have separate roads from the cars. Most bicycle paths are next to the street, as you can see in the first two photos below. There are lots of bicycle-only paths, like the third photo.

The next photo is a bit difficult to describe. Due to the train traffic, few streets cross the train tracks, most go under or over. There is a big tunnel that goes under the train tracks near the town center. There are two separate tunnels for bicyclists and moped riders on the outside, and two tunnels of two lanes for cars and motorcyclists in the middle of the bridge. The sign with a red circle on the border of a car and a motorcycle signifies that cars and motorcycles are not to use the outside path.

If you are wondering about scooters, my experience is that scooters are considered a type of moped. I believe there are six classes of traffic on the road: trucks, cars, motorcycles, scooters/mopeds, bicycle, and pedestrians. I've seen a motorcycle or two take a path valid for scooters/mopeds, but I'm pretty sure this is illegal.

While I was "driving" home from work yesterday, Abtswoudsebrug had to let a boat through. The bridge is only for pedestrians and bicyclists, and it was a bit of a traffic jam.

The second photo above shows a common type of bag placed across the luggage rack of a bicycle.

If you want to see more about the types of bicycles, I suggest this post. The author has a lot of pictures of types of bicycles, and talks about the things that surprise foreigners (buitenlanders). First, helmets are the exception, rather than the rule. Policemen and children wear helmets, but no one else. Second, formally dressed individuals ride bicycles, even women in skirts. A girl will sometimes wear a skirt over tight black pants, I'm assuming the pants protect against the cold and make riding a bicycle less awkward. Third, it is common for a second person to ride on the luggage rack. Guys will "ride luggage" (I made that up) with other guys, too, though this is less common.

The only type of bicycle the other post missed mentioning is the folding bicycle. I didn't get a good shot of one, as these bicycles are less common. You see a folded bicycle every now and then on the train. One can bring a non-folding bicycle onto roughly half of the trains, though this requires a special ticket. Folding bicycles are allowed onto all the trains at no extra charge.

I hope you enjoyed the set of photos discussing bicycles in Delft. I'll post updates if I ever find a folding bicycle.


When Will They Learn?

You don't put MIT in an online poll. Or even better, you don't run online polls with tech schools as choices.

The latest victim is here. Looks like Drexel and Texas Tech beat the MIT script kiddies to the punch, though - it'll be interesting to see who wins first. Either way, the web-site is running really, *really* slow. Poor call, Victoria's Secret.

Just One of Those Days

Today is going to be one of Those Days.

I think I'm going to get a wiki with graphviz up and running. It won't be the most productive thing to do, but documenting is always useful.


Bicycles in the States

Colleges are using bicycles to combat car-centered lifestyles.


While browsing the BBC's How Will You Die? map, I came up with the bright idea to start a web-comic based on maps. I do like the maps.

Wacko Political Views

I know this is all over the 'net, but I have deep respect for Colin Powell and his stance on the Republican party's current insinuations:

I'm also troubled by, not what Sen. McCain says, but what members of the party say, and it is permitted to be said such things as: "Well, you know that Mr. Obama is a Muslim." Well, the correct answer is: he is not a Muslim. He's a Christian. He's always been a Christian.

But the really right answer is: What if he is? Is there something wrong with being a Muslim in this country? The answer is: No, that's not America. Is there something wrong with some 7-year-old, Muslim-American kid believing he or she can be President?

Yet I have heard senior members of my own party drop the suggestion: he's a Muslim, and he might be associated with terrorists. This is not the way we should be doing it in America.

During this interview, Powell also mentioned one of the most poignant photographs I've seen. The photo is from a high-quality, New Yorker slideshow.

(props to the New Yorker for being a classy magazine)


Job: Kindergarten Teacher

During my first two weeks in Zuid-Holland, I didn't have regular internet and wrote a lot of posts on my laptop. I have now run out of posts. I've been a bit busy with VHDL the past few days (yesterday I checked roughly 15,000 lines of VHDL into our repository! 14,900 of these lines were code-generated test vectors, however, so I'm not really that productive). Anyways, I don't really have a great post ready, so I'm going to give a high level overview of VHSIC hardware description language (VHDL), a language I've had to use at work recently. This post is geared towards non-technical readers - most of my university friends have taken a processor architecture class which requires the use of a custom hardware description language similar to VHDL.

Nearly all software languages are serial, meaning they completely execute one instruction before starting on the next. Statements have a linear structure, such as:

get out of bed
eat breakfast
clean dishes
check RSS reader for Oog Robot posts
take shower
brush teeth

The correct output of the program relies on the statements being executed *in order*. A reason that computer programs were originally built like this is that sharing is hard. Even in the example above, someone wouldn't want to take a shower while another person was washing dishes. Well, at least in my apartment there would be little reason to sing in the shower.

In contrast is a completely parallel model of execution. In a parallel model, everything occurs at the same time. A simple analogy is a woodworking assembly line and a carpenter. Serial programs are like carpenters - only a few things can occur at a time. I say a few because a good carpenter might cut one piece of wood while she waits for the varnish to dry on another. At the end of the day, however, there is a limit to how many things one carpenter can do.

Parallel programs are like assembly lines, as work can scale with size. While assembly lines can do a lot more work, they are not as easy to set up. The amount of coordination must also scale with the number of workers. The output and input of subsequent stages must match in attributes like volume and timing, or else mishaps such as pile-ups start to occur.

For a concrete example, say we want to make a peanut butter and jelly sandwich. Here are the steps at a certain level of detail:

Take out plate
Take out bread
Take out PB
Take out J
Take out PB knife
Take out J knife
Spread PB on bread with PB knife
Spread J on bread with J knife
Put away bread
Put away PB
Put away J
Put away PB knife
Put away J knife
Put bread together

In a serial program we have to make sure all the instructions are in the right order, and place these instructions in order. In a parallel program, however, we can leverage the fact that some things can occur at the same time. We could have a "bread factory", a "PB spreading factory", a "J spreading factory", and a "sandwich from pre-spread bread factory".

Bread factory:
Take out bread
Give out bread on request
Put away bread

PB spreading factory:
Take out PB
Take out PB knife
Get bread from "bread factory"
Spread PB on bread
Pass bread w/ PB downstream
Put away PB
Put away knife

J spreading factory:
Take out J
Take out J knife
Get bread from "bread factory"
Spread J on bread
Pass bread w/ J downstream
Put away J
Put away knife

Sandwich factory:
Take out plate
Take PB-bread from PB factory
Take J-bread from J factory
Put slices of bread together

Thus the factories can work at the same time. The sandwich factory and J-bread factory can be taking out plates and J, respectively. Note that while we have more instructions overall due to coordination (and I've even skipped some coordination instructions), each of the specific units is much simpler than the entire program. Understanding a complex system requires breaking down functionality into smaller chunks. Serial programs also aggregate functionality for understandability in a similar way.

As computers evolve it will be interesting to watch the two types of programs evolve. The speed of computer processors has not increased much over the past few years. Processor manufacturers have started to put multiple sets of older, single processors (called cores) into their fancy new processors. Small modifications to serial programs can easily take advantage of a few of these cores, but major modifications or complex procedures are required for serial programs to take advantage of a lot of cores (more than, say, 16).

Anyways, I work with field-programmable gate arrays (FPGAs), which require parallel programs. I'm writing software and coordination routines which allow a light sensor (like your eye) to talk to a display. One can implement serial programs, but one must write a parallel program with complex signaling to do this (or take a freely available one). Thus a good statement of my job is that right now I'm coordinating interactions between a bunch of components. Except the components are like my red-headed stepchildren, and they really don't want to talk to one another. Especially that ones that aren't supposed to be talking to one another.


Cartoon Off

I don't like to post about links I see from reddit.com, but the cartoon-off between XKCD and the New Yorker is the classiest thing to happen this year.


I'm Horrible at First Person Shooters...

...but unfortunately my experience with other computer games implies I have quick reflexes. Supposedly quick reflexes are not good in a lover.

Hmmmm, would I rather have poor reflexes or be a good lover? Tough call.

Small-town Iowa in the News

It is pretty rare when I come across an article about a small town in Iowa, but within the last day I've seen three. Probably just coincidence.

A Class Divided - with the increasing focus on race in the current presidential campaign, PBS hopes to teach people with the anecdotal evidence of a 1970 discrimination experiment in Riceville, IA.

Immigration Problems - Still angry at the recent raids on a meat packer in Postville, IA, politicians blame the gov't for the increase in crime and drop in business. Meanwhile in the US, there still is no immigration path for unskilled workers.

The Oxford Project - 20 years later, a new book focuses on the residents of Oxford, IA. Probably just a PR article.


Exposure Troubles

I couldn't get the levels quite right. Even in the original, high-res version the middle clouds look a little blocky, and the trees below the cloud line are too dark.


Vacation in Iceland?

With Iceland's financial collapse, your dollars (or euros) will buy a lot more in the small country. Assuming you can find food to buy.

A Trip to the Bank

Despite what google tells you, "to pull" in Dutch is "trekken". Trekken also means "draw", in both the "draw on" and "horse-drawn carriage" sense of the word draw. "To push" is "buwen".

Dutch fire code does not require doors to open outward like American fire code requires, meaning you shouldn't assume that a door opens outwards when outside a building. These sorts of assumptions will screw you when you're attempting to enter the bank. There will be a bunch of giggling teenage girls are behind you, and you'll never forget that "buwen" means push. And they said degrees from MIT would help open doors. Lies.

I wonder why the Dutch don't take fire code so seriously. Doors in America always open outwards so no one gets trapped behind the door. And there aren't embarrassing moments like these. Well, at least not outside of buildings.

Anyways, on to the main point of this post, a short discussion about differences in banking. In order to open a bank account at ABN-AMRO, a bank in the Netherlands, one must schedule an appointment several days to a week in advance. I don't know if it is ABN-AMRO specifically, but an email I received from HR implies that all banks are this way. I've opened three checking accounts in America with three different banks, and every time I just walked in and 15 minutes later I walked out with a checking account.

Two weeks after said embarrassing encounter and several days after my appointment, I received my debit card in the mail. Instead of a 16 digit credit card number, my account number is on the debit card! Putting a different, 16-digit number onto a debit card serves two purposes to my knowledge. The first reason is that a debit card can have the same interface as a credit card - sellers don't need two different mechanisms for payment. It would be a big hassle to parse two sets of information, go to a different interface based on the info, etc. The second reason is that your debit card doesn't contain your account number, so your account number is not suspect if you lose your debit card. Every American check contains one's account number, however, so I suppose it isn't so bad if the account number is compromised.

The debit card also has a formatted version of my name, an expiration date, and a "card number" which contains roughly the same amount of information as the CVV number of the back of my American credit cards (short aside: did you know that Canadians hate it when US citizens call themselves American? They're North American, and hence American, too). The card is called a "Wereldpas", meaning (you guessed it) "world pass". The card also contains a ChipKnip contact.

ChipKnip, from my limited understanding, is a standardized interface to vending machines and small payment devices. You have to go to a special ATM-like machine to take money from your main account and place this money onto/into the ChipKnip portion of your card. At my appointment the teller described ChipKnip as a coin-purse on your debit card, but quickly moved on, probably not wishing to stretch her English nor explain such a "basic" concept. I'm very interested in the security of the device. How do you prevent people from taking advantage of ChipKnip? Expect a post sometime in the future as I learn more about how the ChipKnip device works.

Roughly a day after the mailman delivered my debit card, I received an authentication device for internet banking, and a letter thanking me for asking not to receive paper statements. I'll be writing more about the security of this device in a later post.

For all the trouble I went through to setup a bank account, there won't be much money in it until next month. I need a SoFi number (social fiscal, Dutch equivalent of SSN) before the Universiteit can pay me. Until then I'll be eating pasta.

(This post was written on my laptop, before I had regular internet access. No animals were harmed, though some red tape did suffer damage.)



I'm all for multi-tools, but 85 implements is a bit absurd.


SPADs mentioned at Ars Technica

Ars Technica mentioned single photon avalanche detectors (SPADs) in an article on quantum crypto today. I'm working with these avalanche detectors - I'll be giving an overview on SPADs pretty soon on my blog. Stay tuned!

Inches overseas

Computer/laptop monitor sizes in Europe are *not* reported in centimeters, as one expects, but in inches. A 19" monitor is a 19" where ever you go. I don't think I've run across anything else in inches.

TV screen sizes are reported in cm, though.


I Knew It!

When speed dating, women are nearly as shallow as men.

Strong evidence that women base a first impression on the same characteristics as men.


This post contains a description of reserving my apartment, and a breakdown of my apartment. Note that when I talk about floors (1st floor, 2nd floor, etc.), I mean European floors, which are 0-indexed.

Reserving my apartment was simple. An HR rep forwarded me a DUWO (short stay housing company) form which needed to be filled out at least three months in advance. Seriously, everything takes three months in Holland. After completing and returning the form, I received a confirmation letter via email. I showed up at the housing agency, paid my deposit and rent (they take cash), and received my keys. There is an indoor bike shed I can use when I buy my bicycle. The floor hallways are outside.

Security is physical key based. Everyone has a mailbox key. The second key is used to open the ground-level doors, your bike shed's door, your floor's door, and your room's door. There is also an emergency exit. While your key only opens your particular floor's door, the emergency exit doors aren't locked. I made the 13 floor journey to get photos from the 17th floor.

My apartment is a pretty standard studio apartment. The apartment came furnished...well, European furnished, as the coffee mug is a bit small. The heating is pretty bad, temperature stays at 20 Celsius (68 Fahrenheit) during the day, at night it drops to 15 Celsius (59 Fahrenheit). According to the rental agreement my room can be searched at any point in time. I am not allowed to:

- have guests stay overnight (doubles aren't allowed to have more than two people stay overnight)
- add appliances (microwave, rice cooker are used as examples, no rigorous definition of appliance is given)
- drives nails anywhere
- paint

I wonder if you can get kicked out of the country for breaking your rental agreement?

The apartment consists of three rooms and an entrance. The entrance is pretty non-chalant, so I'll go over the rooms from worst to best.

The bathroom is horrible, and the German shelf-toilet will give me nightmares for years to come. With an American toilet, one's business goes into water, but no water covering means that the bathroom smells compared to an American one. There are other shortcomings, but there is something called "Too Much Information". Google information about German toilets if you are interested.

The shower gives out hot water, but the water pressure is awful (I played around with the values, but don't think I can adjust this from my apartment). There is no good de-humidifying method, so the mirror stays fogged up after a shower. The shower lip keeps the water near the shower, but the floor is curved away from the shower lip and the toilet sits in a depression - accidently spraying water over the shower lip means a pool forms near the toilet. This is easily the worst bathroom I've had. Possibly even worse than the shallow Goodale bathroom when it turned sketchy my sophomore year.

The bathroom is so awful I hope no one wants to come and visit me until I find a better apartment. (Everyone I've told still has a standing invitation, but I'll sweat bullets worrying about my bathroom)

The kitchen is a mixed bag. I don't have a microwave nor oven, and since I'm a rule-follower to the letter there will never be one in my apartment. The kitchen came with hot plates and a pot, so I'm pretty set on pasta. The fridge is okay, there isn't a freezer (no ice cream!) but it is bigger than a standard cube fridge.

The main room is huge. Seriously, I could host a party in here (not going to happen). There are two massive West facing windows, both keep my apartment hot at the end of a sunny day. The windows are semi-opaque from one meter off the ground to two meters off the ground so people walking by can only see your floor and ceiling. The bed is a bit too springy. This surprised me, as Dutch people are tall (average adult male height is 6') and taller people usually sleep on firm mattresses. Otherwise one's spine gets tangled up and you wake up with a sore lower back.

My room number is actually my street address. Rooms are odd-numbered from 3 to 749 over 17 floors. Roughly 400 people live in my building (more on Dutch apartment buildings later). The first number of a room doesn't correspond to the floor, my room is in the 100s but I live on the fourth floor. There are five washers and three dryers. For 400 people, 5 washers! The laundry machines are small, too: 1 American load == 1.5 European loads. Laundry is expensive at 2 euros per wash or dry, and will run about 6 euros (10 dollars) a week for me. The laundry machines suffer concurrency issues like nobody's business on the weekends. Poor engineering, not enough redundancy.

All and all, I'm pretty happy with my place. Large windows can compensate for a lot. Watching the sun set, I remind myself how important it is to take it all in. One day the sun will be gone (preferably at my hand), and it will no longer set in the west. Muahaha.


The World is Quiet Here

I just moved into my office, and I have a sweet view of the library. And the Ikea.

But mostly the library. I love TU Delft's library.