Friday, June 11, 2010
He finally does it.
Congrats Wheating on your victory over the freshman wonder. Now run some fast times over in Europe already. Well, after the 1500m tomorrow anyway.
Saturday, June 5, 2010
The Current State of American Distance Running
He finally did it. Bernard Lagat broke the US 5k record today, finishing third in Oslo with a 12:54. Ignoring for a minute all the arguments that Lagat is not a true American (seriously?), I am proud to say three Americans have broken 13 minutes in the 5k over the last year, with the American record being reset twice. Furthermore, the men's US 10k record was recently broken (sub-27:00!) by Chris Solinsky with an amazing finish at the Payton Jordan Invitational at Stanford, the US women finished third at World Cross this year, and two Americans (Meb and Shalane) have medaled in distance events at the two most recent Olympic games. The United States is no longer chasing the west Africans - we are now actually competing with them.
For a number of years (from the 80s to the early 2000s), the running community believed American distance running was in decline. Only Bob Kennedy could run with the Kenyans, though even he never obtained a World Championship or Olympic medal. However, taking a look at recent events, I would say we can feel good about the current state of American distance running. I am not sure what exactly we are doing right (hopefully not EPO!), but I am getting excited about what the future may bring.
For a number of years (from the 80s to the early 2000s), the running community believed American distance running was in decline. Only Bob Kennedy could run with the Kenyans, though even he never obtained a World Championship or Olympic medal. However, taking a look at recent events, I would say we can feel good about the current state of American distance running. I am not sure what exactly we are doing right (hopefully not EPO!), but I am getting excited about what the future may bring.
Friday, June 4, 2010
Proof Math is Beautiful
I just thought I would point you all to Proof Math is Beautiful, an online blog of pictures arising from mathematics.
Validity of Computational Simulation
As a computational scientist, I believe it is important that I question the validity and reliability of my work. And that is precisely what I will be talking about today.
Computational simulation is a strange game. The entire process of simulation can usually be laid out as follows:
(1) Development of a mathematical model which approximates reality.
(2) Development of a computational model which approximates the mathematical model.
(3) Extraction of useful information from the computational model.
Item (3) has little room for error. Item (2) is more prone to error. However, we have a good understanding of how to estimate or control this error and thus verify our computational model. In many cases, we can use hard mathematical analysis to quantify how different our computational model is from our mathematical model. We can use adaptive methods to control this error and even drive the error to zero. Item (1), on the other hand, can be a bit of a mystery.
The process of determining how well a mathematical model approximates reality is known as validation and is currently an extremely hot topic in computational science. The most common validation techniques involve comparing the results of a mathematical model to those of reality for certain, often simple, explicit scenarios. These validation experiments are often combined with parameter estimation in order to arrive at "better" models. However, these validation experiments by no means quantify how close our model is to reality in every scenario. In fact, it is often impossible to validate a complex system for even simple scenarios. The data just simply isn't there. How can we begin to trust our model when validation isn't even an option? Furthermore, we run into more awkward situations when we have an abundance of data. In these situations, one often finds it is impossible to tune parameters in order to eliminate error from every validation experiment. One either has to either (i) introduce more parameters and hence introduce a more complex model or (ii) choose a subset of validation experiments. Option (ii) immediately seems like a cop-out. However, option (i) often leads to models that aren't even computationally tractable. Of course, one can point to the rapid increase in computational resources and say, "Just wait a few years. Then we can simulate whatever we want." However, as our computational resources have become larger, so have our problems, often at a faster rate. Will this trend continue? I feel that these are important questions that we as computational scientists often ignore.
One last thought: if we can, theoretically, pinpoint the "modeling" error associated with a mathematical model down to say 50%, is there a reason to adaptively reduce the "mathematical" error associated with a computational model to, say, below 5%? Or, more simply put, shouldn't we establish a direct relationship between validation and verification?
With all this in mind, I pose the same question that one of my mentors, Professor Ivo Babuska, often does: "Will you sign the blueprints?"
Computational simulation is a strange game. The entire process of simulation can usually be laid out as follows:
(1) Development of a mathematical model which approximates reality.
(2) Development of a computational model which approximates the mathematical model.
(3) Extraction of useful information from the computational model.
Item (3) has little room for error. Item (2) is more prone to error. However, we have a good understanding of how to estimate or control this error and thus verify our computational model. In many cases, we can use hard mathematical analysis to quantify how different our computational model is from our mathematical model. We can use adaptive methods to control this error and even drive the error to zero. Item (1), on the other hand, can be a bit of a mystery.
The process of determining how well a mathematical model approximates reality is known as validation and is currently an extremely hot topic in computational science. The most common validation techniques involve comparing the results of a mathematical model to those of reality for certain, often simple, explicit scenarios. These validation experiments are often combined with parameter estimation in order to arrive at "better" models. However, these validation experiments by no means quantify how close our model is to reality in every scenario. In fact, it is often impossible to validate a complex system for even simple scenarios. The data just simply isn't there. How can we begin to trust our model when validation isn't even an option? Furthermore, we run into more awkward situations when we have an abundance of data. In these situations, one often finds it is impossible to tune parameters in order to eliminate error from every validation experiment. One either has to either (i) introduce more parameters and hence introduce a more complex model or (ii) choose a subset of validation experiments. Option (ii) immediately seems like a cop-out. However, option (i) often leads to models that aren't even computationally tractable. Of course, one can point to the rapid increase in computational resources and say, "Just wait a few years. Then we can simulate whatever we want." However, as our computational resources have become larger, so have our problems, often at a faster rate. Will this trend continue? I feel that these are important questions that we as computational scientists often ignore.
One last thought: if we can, theoretically, pinpoint the "modeling" error associated with a mathematical model down to say 50%, is there a reason to adaptively reduce the "mathematical" error associated with a computational model to, say, below 5%? Or, more simply put, shouldn't we establish a direct relationship between validation and verification?
With all this in mind, I pose the same question that one of my mentors, Professor Ivo Babuska, often does: "Will you sign the blueprints?"
Thursday, June 3, 2010
Screening for Celiac Disease
In approximately a month, I will be traveling to Italy for a workshop on "Non-Standard Methods for PDEs". While the trip sounds super exciting, in the past few weeks, I started becoming nervous about my travels abroad. Notably, I was concerned about what I, as a celiac sufferer, could eat in the land of pasta and bread. Thankfully, I recently found out Italy is a haven for celiacs. Nearly every pharmacy in Italy has an aisle or two dedicated to gluten-free food, and most chefs in the country will prepare gluten-free pasta if requested to do so. Celiacs are given two paid days a month to shop for grocerties, and further, they are given financial aid to offset the high cost of gluten-free items. Reading all this again makes me wonder if I shouldn't just stay in Italy while I am there =P. Finally, children in Italy are screened for celiac disease by the age of five.
In the United States, celiac screening is not a common occurrence. I had been tested for just about every other digestive disorder before a doctor even suggested celiac disease. I was diagnosed with IBS and lactose intolerance, and while I adjusted my diet accordingly, nothing seemed to help. Luckily, celiac is now more widely recognized. Many grocery stores have gluten-free sections, May has become celiac awareness month, etc. Still, I believe more progress must be made. Children are usually only screened if there is a family history of celiac or if other underlying conditions (such as Type 1 Diabetes or Downs Syndrome) exist. Children and adults are most often misdiagnosed in the presence of digestive symptoms. This needs to be changed. Celiac disease can cause a multitude of issues down the road, not the least being colon or bowel cancer. I believe doctors in the United States need to be educated on celiac and that they should take the initiative with regards to screening for celiac and other common diseases. Finally, I believe that mass screening, as is done in Italy, might be a viable and cost-effective option.
In the United States, celiac screening is not a common occurrence. I had been tested for just about every other digestive disorder before a doctor even suggested celiac disease. I was diagnosed with IBS and lactose intolerance, and while I adjusted my diet accordingly, nothing seemed to help. Luckily, celiac is now more widely recognized. Many grocery stores have gluten-free sections, May has become celiac awareness month, etc. Still, I believe more progress must be made. Children are usually only screened if there is a family history of celiac or if other underlying conditions (such as Type 1 Diabetes or Downs Syndrome) exist. Children and adults are most often misdiagnosed in the presence of digestive symptoms. This needs to be changed. Celiac disease can cause a multitude of issues down the road, not the least being colon or bowel cancer. I believe doctors in the United States need to be educated on celiac and that they should take the initiative with regards to screening for celiac and other common diseases. Finally, I believe that mass screening, as is done in Italy, might be a viable and cost-effective option.
Wednesday, June 2, 2010
Some Thoughts on Barefoot Running
The barefoot running phenomena has certainly caught fire recently. With the release of Born to Run by Christopher McDougall, every yuppie in YuppieTown is running to their local REI or running store to buy a new pair of Vibrams. "It's natural." "Surely, if I run barefoot like our ancestors did, I will stop getting injured." Maybe. But probably not.
I can certainly agree that there are many good reasons to go barefoot (or at least more minimalist). Our foot muscles have become weaker running in heavy clonkers. But that's just the thing - our foot muscles are weaker, and we need to respect that. Namely, if one elects to go minimalist, one needs to take a very long time getting there. I am not talking about starting off walking in the Vibrams for one mile a week and then proceeding from there. Hell, some people, including my sister, have gotten injured that way. That way is still too fast. I am talking about a multi-stage approach to barefoot running. Slowly introduce a slightly lighter shoe into your running over the course of a few months. Then, once you have adjusted to that shoe, continue running in that shoe for a few months before introducing an even lighter shoe. Yadda yadda yadda. This process takes years, not months. If you take it too fast, you will certainly get injured.
Even though I do agree there are reasons to go barefoot, there are some things I would like to make clear before I proceed: (1) going barefoot is not necessarily going to make you a faster runner, (2) going barefoot is surely not the only way to become a faster runner, (3) if you get injured running barefoot, your barefoot running (and perhaps not your training!) might be at fault (check out http://www.sportsscientists.com/), and (4) if you wear Vibrams, I will still point and laugh.
There has also been some talk among the blogosphere that perhaps we weren't all *gasp* born to run. See, for example, this article by Matt Fitzgerald, which consequently has been blasted by a lot of minimalist runners. The idea is that every cheetah is a world-class sprinter. However, not every human is a world-class long distance runner. In fact, there is a ton of variation. Humans have a wide variety of talents and skills compared to other animals. Some just simply aren't that great at running. Are these folk perhaps not born to run? To quote Matt, "The romantic vision of an Edenic primitive humanity in which everyone ran like Kenenisa Bekele is complete hokum. Endurance running was very likely only ever a specialization of the few, exactly as it is today." I am not saying that I completely agree with Matt and his article, but I do agree we need to read books such as Born to Run with a grain of salt.
Some last thoughts. Minimalist running does not necessarily mean Vibram running. I run much of my mileage in racing flats, and many consider this minimalist. However, if you must insist on running in ugly shoes to the same effect as the Vibram Five Fingers, save yourself a few dollars and buy a cheap pair of water shoes. They're so much less expensive and still protect your feet. And Vibram isn't such an innocent company. They have funded many of the studies illustrating the advantages of the Five Fingers. For example, Vibram funded research done at Harvard which concluded there is less pounding associated with running 25 meters barefoot than running 25 meters in heavy shoes. And we all know 25 meters is roughly a marathon. Okay, that was harsh. I agree there are many reasons to go barefoot. Just please don't look like this guy while channeling our ultra-marathon ancestors.
I can certainly agree that there are many good reasons to go barefoot (or at least more minimalist). Our foot muscles have become weaker running in heavy clonkers. But that's just the thing - our foot muscles are weaker, and we need to respect that. Namely, if one elects to go minimalist, one needs to take a very long time getting there. I am not talking about starting off walking in the Vibrams for one mile a week and then proceeding from there. Hell, some people, including my sister, have gotten injured that way. That way is still too fast. I am talking about a multi-stage approach to barefoot running. Slowly introduce a slightly lighter shoe into your running over the course of a few months. Then, once you have adjusted to that shoe, continue running in that shoe for a few months before introducing an even lighter shoe. Yadda yadda yadda. This process takes years, not months. If you take it too fast, you will certainly get injured.
Even though I do agree there are reasons to go barefoot, there are some things I would like to make clear before I proceed: (1) going barefoot is not necessarily going to make you a faster runner, (2) going barefoot is surely not the only way to become a faster runner, (3) if you get injured running barefoot, your barefoot running (and perhaps not your training!) might be at fault (check out http://www.sportsscientists.com/), and (4) if you wear Vibrams, I will still point and laugh.
There has also been some talk among the blogosphere that perhaps we weren't all *gasp* born to run. See, for example, this article by Matt Fitzgerald, which consequently has been blasted by a lot of minimalist runners. The idea is that every cheetah is a world-class sprinter. However, not every human is a world-class long distance runner. In fact, there is a ton of variation. Humans have a wide variety of talents and skills compared to other animals. Some just simply aren't that great at running. Are these folk perhaps not born to run? To quote Matt, "The romantic vision of an Edenic primitive humanity in which everyone ran like Kenenisa Bekele is complete hokum. Endurance running was very likely only ever a specialization of the few, exactly as it is today." I am not saying that I completely agree with Matt and his article, but I do agree we need to read books such as Born to Run with a grain of salt.
Some last thoughts. Minimalist running does not necessarily mean Vibram running. I run much of my mileage in racing flats, and many consider this minimalist. However, if you must insist on running in ugly shoes to the same effect as the Vibram Five Fingers, save yourself a few dollars and buy a cheap pair of water shoes. They're so much less expensive and still protect your feet. And Vibram isn't such an innocent company. They have funded many of the studies illustrating the advantages of the Five Fingers. For example, Vibram funded research done at Harvard which concluded there is less pounding associated with running 25 meters barefoot than running 25 meters in heavy shoes. And we all know 25 meters is roughly a marathon. Okay, that was harsh. I agree there are many reasons to go barefoot. Just please don't look like this guy while channeling our ultra-marathon ancestors.
Tuesday, June 1, 2010
A Silly Name, A Serious Game
Last night, a friend of mine pointed out a hilariously named CS article that had just popped up on the arxiv, notably "Simple Wriggling is Hard Unless You Are a Fat Hippo". Upon reading this title, I recalled SCIgen, the automatic CS paper generator (see http://en.wikipedia.org/wiki/SCIgen), and surely thought there must be a connection. But alas, there was none. Here it was: a paper with a silly name but a serious game.
The paper of interest actually involves a proof of the difficulty of finding an approximation of the shortest "thin" path between two points in a polygonal domain (i.e., that the problem is NP-hard). The title is a play on words, utilizing the connection between "thick" paths and "hippo"-dromes. Even the paper's chapter titles are cheeky, with gems such as "Snake Anatomy and Physiology" and "Being a Long Snake is Hard".
Motivated by this awkward title, I spent about a half hour in search of other serious papers with silly names. I, unfortunately, was vastly unsuccessful in this effort, but I did come across a number of notable silly papers. Of particular note are "Chicken Chicken Chicken: Chicken Chicken" by Dr. Doug Zongker of the University of Washington and "The Theory of Interstellar Trade" by Dr. Paul Krugman of Yale University. I was particular impressed with "Theory of Interstellar Trade" and the question it seeked to answer: "How should interest charges on goods in transit be computed when the goods travel close to the speed at light?" In this 1978 paper, Dr. Krugman pointed out that such a question was quite valid with the then recent progress in the technology of space travel. However, with Mr. Obama's recently proposed NASA budget cuts, we may never see if Dr. Krugman's hypotheses regarding interstellar trade ring true.
UPDATE: I finally did the obvious thing of researching the conference where "Simple Wriggling" will be presented and came across a slew of talks with fun titles and serious messages (for the most part). Check out the program here.
The paper of interest actually involves a proof of the difficulty of finding an approximation of the shortest "thin" path between two points in a polygonal domain (i.e., that the problem is NP-hard). The title is a play on words, utilizing the connection between "thick" paths and "hippo"-dromes. Even the paper's chapter titles are cheeky, with gems such as "Snake Anatomy and Physiology" and "Being a Long Snake is Hard".
Motivated by this awkward title, I spent about a half hour in search of other serious papers with silly names. I, unfortunately, was vastly unsuccessful in this effort, but I did come across a number of notable silly papers. Of particular note are "Chicken Chicken Chicken: Chicken Chicken" by Dr. Doug Zongker of the University of Washington and "The Theory of Interstellar Trade" by Dr. Paul Krugman of Yale University. I was particular impressed with "Theory of Interstellar Trade" and the question it seeked to answer: "How should interest charges on goods in transit be computed when the goods travel close to the speed at light?" In this 1978 paper, Dr. Krugman pointed out that such a question was quite valid with the then recent progress in the technology of space travel. However, with Mr. Obama's recently proposed NASA budget cuts, we may never see if Dr. Krugman's hypotheses regarding interstellar trade ring true.
UPDATE: I finally did the obvious thing of researching the conference where "Simple Wriggling" will be presented and came across a slew of talks with fun titles and serious messages (for the most part). Check out the program here.
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