I know vdov doesn’t usually go for the “hey look at this cool thing on the internet” type of posts but, hey look at this cool thing on the internet. It is clearly the greatest music video that has ever existed. It also dominates the field of “zombie Stalin” videos as well. It’s by a Russian metal band called ANJ [their myspace page].

I’m used to writing in C (and Matlab, unfortunately), though I’m not particularly proficient in either. But lately I’ve taken on C++ and holy hell what a huge language. Still, it has a lot of nice features that are going to be important to me in the next year of my graduate work and I’m gonna stick with it. Yay OO, ugh.

For all its size, one of the areas where I have been left completely unsatisfied is in support for threads. Yes, of course POSIX threads are there and I’ve had some success implementing them in some of my older, now completely obsolete C code which I never want to look at again. It’s baffling to me that there is nothing in the STL which develops some nice thread classes. I know there are at least 2 (if not more) very experienced C++ programmers who read vdov.net, and I’m looking for advice. Have you looked at some developed thread classes and if so what have you thought? Recommendations? I would really rather not have to write my own thread classes from scratch (especially since accessing the C pthread library would be a nightmare here), as this is both utterly useless for my research and, well, I’d probably screw it up with near-fledgling knowledge of the language.

Cheers.

I hate advertisements and, more specifically, advertisements on my clothing. This is one of the reasons why I wear GoodWill t-shirts: I don’t want to be a walking, talking billboard. This choice has brought me rather frequent social t-rauma (see exhibit 1) and I haven’t suffered alone. A recent news headline was A man was threatened with arrest for wearing a Transformers t-shirt. A couple of weeks ago my “Central Ohio Senior Olympics 1997” shirt caused me t-rauma, albeit far less public.

A man approached me while I stood in line at the Subway on the University of Chicago campus. He said, looking at my shirt, “Really? You think so?” I stared at him blankly. He continued “Are you from the area (central Ohio)?” Realizing he was talking about my t-shirt, I said “Yes”. The man replied “Well, welcome to intellectual heaven!” and walked away smiling. Still standing in line, I started to stew about this brief exchange:

Subway is intellectual heaven!? Is being from central Ohio or wearing a central Ohio t-shirt a sufficient qualification for admittance into intellectual heaven? Very unlikely.

Was I just welcomed by an (the) intellectual god? If yes, then I met an (the) intellectual god, a “sandwich artist,” and “ate fresh” in intellectual heaven after what must have been my untimely intellectual death.

What caused my intellectual death? I’d guess being constantly bombarded with advertisements and repeated t-rauma from my choice of t-shirts.

But wait! Where is intellectual hell? How can I be trying to answer such deep questions while reading mind-numbing advertisements for Doritos (taking snacking to a higher level), Mountain Dew (the new dew is up to you), Subway (eat fresh live green)? Am I really in intellectual hell?

[Update]: Is my hatred of advertisements legal in Canada?

The storm season in Indiana has been particularly active this spring/early summer. A couple weeks ago we had one hell of a storm come through north-central Indiana, hitting northern West Lafayette the hardest. It remains the only storm I have ever been through (and I’m including living in Florida for 9 years) which has actually scared me/caused significant damage.

This was a nice storm: decent MCS and individual supercell formation leading to a squall line. Loving thunderstorms and the study of weather as I do (thanks Meyers!), I was pretty busy taking pictures/watching/looking at weather data when I saw a swirling cloud of debris headed straight for the back of the house. I figured it couldn’t be that big of a deal so I just sat there and watched. Then the 100 mph winds hit the house and I hit the deck (and subsequently an interior room). While the damage to our house was moderate (shingles, aluminum siding and gutters missing, thrown AC unit, etc.), some other people right down the street didn’t fare so well.

Pictures of the storm and of some of the damage are available here.

Cheers.

I put up some (long overdue) pictures, some of my favorites, on the web for people to check out. It was one of the best times of my life. We spent the majority of our time on Molokai, some place I really want to go back to some day. The wedding was absolutely perfect, right on a completely deserted beach on the west side of the island at sunset. We even saw some humpback whales as the ceremony concluded.

Other notable events: crazy single engine Cessna ride to the island, touring the Leper colony after having hiked down (and subsequently hiked up) the tallest sea cliffs in the world. If you recognize those, it’s because Jurassic Park 2 & 3 were filmed there. And of course the cover of my first boy band album.

Congrats Mica & Jason! It was amazing, I was so happy to be there!

Cheers.

My love for South Park is well know. As such, while I was at this year’s ASMS conference in Denver, Lucas, Lindsey and I took a trip down Colfax avenue to go to Casa Bonita! It was amazing. Pretty much everything from the South Park episode (which, if you haven’t watched it is easily in my top 10) was there. Most importantly this includes the cliff divers (yes, they really dive) and Black Bart’s hideout. I put some pictures up online. You can find them here.

Cheers.

PS: The Colfax avenue bus is quite an experience.

One of the major cases before the Canadian “Human Rights Commissions” has concluded and awarded a win for free speech. While the outcome is gratifying the fact still remains that the Canadian government still believes it just and correct to regulate speech, which I (and many others) posit should be free and unfettered despite its message or content.

This has been one of the few “political” topics followed by vdov.net but I believe it has been an appropriate topic. For a little more background on the Canadian “Human Rights Commissions” vis a vis free speech you can see this previous article. Any debate and/or comments on the topic are always appreciated.

I was having some fun with taking pictures around the house with my new lens, so I thought I’d share. Besides, this may be the only reasonable way to up my posting on vdov, especially since I don’t think anyone pays attention to my gallery (but I will add the images there, too: shollen.vdov.net …visit sometime). (more…)

This story is both scientifically interesting and hilarious in some places; you should continue reading it. I’ve divided it into several parts, as it is fairly long. It involves science, scientific politics, and gracious insults. Most importantly, it discusses how my lab at Brown University has shown strong evidence for the existence of Cooper pairs in insulators. In case some readers are backlogged on their scientific jargon (do they have RSS feeds for that?), I’ll describe what I mean. (more…)

I am sure that the vdov authorship remembers our old, Canadian pal who ever so politely and succinctly let us know that “…hate is illegal in Canada.” The sacrifice of free speech at the altar of “not being offended” has now come to fruition in our good Nation to the North.

For those not closely following (anything in Canada) the dust up over free speech in Canada I will provide a couple basics. Several individuals including Ezra Levant and Mark Steyn have been hauled before provincial “Human Rights Commissions” to be tried for things they have said or written that may have offended individuals or groups. The idea being that what these individuals wrote or said was “hate speech” that disenfranchises people.

My general view is that all speech should be free, naturally. I take the “sticks and stones” approach with the caveat of speech that incites immediate violence. I am very much in line with standard American legal thinking. By placing restriction on forms of speech considered “offensive” or “hateful” a broad and completely subjective stifling of speech can occur which I find completely unacceptable. The point of all of this being that the current “trail” of Mark Steyn for his writings provides an excellent example of the farcical nature of limiting some forms of speech “for the greater good.” Andrew Coyne has been liveblogging the trial of Mark Steyn. The whole process is not only ridiculous from the standpoint of truly free speech it crosses into the realm of self parody because the Human Rights Council itself seems completely unable to justify or conduct itself in any kind of competent legal framework.

I am hoping that folks around here will take a crack at this one. It’s at least worth some discussion.

I’m drawn to writing with a clear purpose and logical structure: writing that places the readers’ consumption of the content above all else. When studying a technical subject, I attempt to find the clearest, most concise text(s) available. That is, I look for the book or books that will expose the roots of the area. Further, I find reading more fruitful when the text is designed to lay a foundation for a field using a line of reasoning with a concise argument or set of arguments, as opposed to a purely axiomatic or pedagogical approach.

Typically, such books are shorter than those I use for reference and much longer than a wikipedia article - they are in between. I’ve taken to calling these books “tweeners” (n., pl., pronounced tee-wieners), as in “they are be-tween-ers”. Another possible term was “t’ain’ts” (n., pl., a contracted contraction of it with ain’t), as in “t’ain’t a wikipedia article and t’ain’t a reference book”. While I prefer the equally appropriate term t’ain’t, the unfortunate (inappropriate) slang meaning justifies avoiding this collision of terminology (no link). There are also less severe collisions with “tweener”:

Let it be understood that I am not referring to a tweener, n., (1) a person capable of playing multiple positions in a sport, (2) a person that falls between two age generations, (3) a bowling form, (4) a hobbit between the ages of 20 and 32 or (5) a man that looks like a woman or vice versa.

Currently, I’m reading A.I. Khinchin’s “Mathematical Foundations of Statistical Mechanics”. It’s definitely a tweener! As far as I know, the readers (and writers) of vdov.net are a diverse group. Do you have a tweener? Are you man, woman, man that looks like a woman, woman that looks like a man or hobbit enough to share it?

For awhile now I’ve been doing distributed computing based on two major methods: the METIS graph partitioning method for decomposition and the MPI method for parallelism. Both of these techniques are well established and used extensively in many fields of computational physics, engineering and chemistry. I’ve been doing simulations in a simple mesh for a few months now. This mesh is simply a box with 200 x 200 x 200 cells. I decompose the box into 8 parts, each part to be run on a different processor using MPI as the construct to deal with processor-processor boundaries/communication. It occurred to me that the METIS method does something particularly ridiculous in this case.

If you simply break the box up into 8 pieces, the easiest possible way to do this is just to simply cut through the planes of the box. The faces of the global box do not exist on processor boundaries, as I apply boundary conditions on all these faces. Each cutting plane has 200 x 200 faces, so you don’t need a CS or math degree to know that the number of processor faces in this case would be 120,000. Is this what METIS gives you? No! It gives you 164,033 processor faces. What the hell?

Here’s a little graph of what this looks like (excuse my very quick and dirty xfig’ing). The width of the boundaries is directly related to the number of processor-processor faces between each decomposed domain.

While there is some obvious symmetry here (within a certain level of approximation), this yields far from the cleanest solution. While METIS may be fantastic for complex domains, it doesn’t do well with simple domains with obvious symmetry. Further, each domain should have a maximum of 3 processor-processor boundaries! It’s important to note here that in fact each processor has 3 major processor-processor boundaries (each node has 3 wide connections — this tell us that METIS is in fact roughly trying to get to the optical structure described above). It’s all the little connections that would be removed with some knowledge of the basic full domain structure. I understand and perhaps believe that this could all be due to some convergence criteria in the method which I am unaware of (in my reading of the papers on the subject and the code itself I haven’t found any such parameter), though still, I see no reason why some from-end part of the algorithmic implementation shouldn’t take into consideration the symmetry of the large and subdomain groups.

Cheers.

[UPDATE after the jump] (more…)