Finished door panel prototype

Actually I spent most of the day working on a paper with Andy but there's no cool picture for that. Afterwards I finished the door panel prototype. I think they look pretty good but they were a real pain in the ass. I'd like to do it all over the house but I think I'll wait until I have access to a large mill.

Old media to new media conversion rate? Negligible

I was curious as to what the conversion rate might be from old media such as Science Magazine to new media like this blog so I tracked the hits of this blog during the publication of the Science article about me last week. The answer? Anemic. On the day of the release, only 90 visits to this blog and most of those came from HackerNews because my friend Jim posted it there. Granted, that's a lot more than the background of near zero, but compared to times when my website Mine-Control has been mentioned in obscure blogs, it's nothing. For example, an obscure Spanish art/video site once linked to Mine-Contol and I ended up with a $1000 monthly bill on bandwidth after tens of thousands of hits. A single tag on a social bookmarking site like digg usually generates thousands of hits. So, despite the fact that lots of people read Science, the conversion rate is apparently low. Of course, this is a single biased sample and it might just be that nobody cared enough about that article, but I suspect that it wasn't that much different in interest than any of the much higher converting blog entries I've been on the receiving end of before. So, thinking of advertising in old media and hoping for a lot of resulting web hits? -- maybe not a great idea.

More back seat wall progess

Christmas day progress on the back wall. I built a temporary mold with bricks and leveled out the top surface in preparation for the seat course.

Back seat wall progress

Today I made good progress on the back seat wall on a perfect 60 degree day. It isn't doesn't require any creative thought as the pattern is regular over the whole length so it's an almost meditative task that requires nearly zero brain power.

Diffusively coupled oscillators

Having previously seen the effects that oscillators near 180 degree phase-boundaries run faster, I conducted the experiment of isolating two oscillators and varying the diffusive constant between them (thanks John). This first graph shows the time trace of the two diffusively-coupled oscillators started 180 degrees out of phase. Note how both amplitude and wavelength are different early-on compared to later when the two have synchronized. The next graph shows the peak frequency of the first phase (before phase lock) as a function of diffusion.


I know this is a well-known phenomena and is the basis of reaction diffusion systems so I started hunting for references. First google hit was: PRL 96 054101 - Daido and Nakanishi - Diffusion Induced Inhomogeneity in Globally Coupled Oscillators. They show various facets of a similar system without regard to spatial dynamics (like this experiment). They refernce Erik's father's (A T Winfree) book The Geometry of Biological Time which looks like a must read. They also reference an interesting sounding book: Synchronization - A Universal Concept in Nonlinear Sciences which looks like another must read and the UT library has an online copy!

Feature size varies to the 1/2 power in diffusive latches

I extended yesterday's bi-stable diffusive latach over a larger diffusive range. It was roughly linear over a 0 to 1 domain. It is proportional to the 1/2 power over a larger range. I took Edward's advice and plotted it with error bars and just ignored the deviation information. Here is the sampling over 30 trials with differing random small initial conditions with 1 SD error bars.

Latch with diffusion

Feature size changes with diffusion ... more diffusion, bigger features.


Today I played around with how the diffusion coefficient effects the formation of pattern in the simple latch case. This is an array of bi-stable switches with uninitialized starting conditions (i.e. a little bit of noise). The feature size varies directly with the diffusion. The graph shows that the mean feature size (blue, multiple trials) rises fairly linearly with diffusion as does the variance (standard deviation plotted in red, same trials). There's probably a sexier way to make this plot with error bars or something, I'll think about that.