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Thursday, April 29, 2010

So I might buy a coffee shop...

Well, a third of one anyway. Chris is blogging all the details at LogicsCafe.blogspot.com . I started of just building the financial model for them, but as I became more convinced of the model, I got more enthusiastic about helping run it. I'll graduate with my MS this quarter, spend a year or so running this coffee shop and studying. The only purpose taking classes next year would serve is to discipline myself into studying; but it seems silly to pay upwards of $12k for that motivation, especially when I could end up with a similar amount of owners equity in the same period. Plus, what an awesome experience, right? We'll see how the few unresolved items shake out (ie: liqueur license, signing the lease, signing the loan...).

Returning to a more familiar theme: putting hotter plugs in my bike seems to have improved the starting and running situations. I had inadvertently put the coldest plugs available in it; no wonder they were getting fouled even with the mix screws all the way in.

Its still got some idling issues, but they're different now. It only idles stably at 4k rpm, like before, but now if I close the choke lever by two thirds and reopen it it'll settle down to a nice 1.5k rpm idle. However, it wont come smoothly out of this idle: I have to ease it back up to the 4k level or it'll gasp and die. Once it gets back up to 4k, it stays there unless I do the choke thing again.

I've got the NEVERDIE ambigram tank badge mostly finished. I've been applying coats of polyeurithane to it for the last couple days, its developing a nice clear dome over the embossed letters. It's a race between evaporation in my poorly sealed can and accumulation on the surface to see when it finishes.

Also exciting: I set off car alarms when I ride past them. The neighborhood totally digs me.

On the gardening front: I planted another tomato plant and a pepper in a topsoil bag inside two worn out white t-shirts, hung from my back balcony with four bass guitar strings and a hose clamp keeping the hook from unbending. My garlic are finally all sprouting, I've got some Habanero sprouts, and my ghost pepper seeds have got tap roots. It will be a spicy, spicy fall this year.

Aaand finally, I got the GRE "Big Book;" 54 practice tests. If this isn't good enough, I'm incorrigible. I got a 73% on the test I took this morning. So if I were to do two a day and improve by a half a percent each time, I'd be perfect in less than a month. That's achievable, right?

Monday, April 26, 2010

Brake Cable: Fixed

Headlight: Broken
Spedometer: Inexplicably out of calibration
Sparkplugs: Still getting fouled, but with a little bit of tan coloring on the electrode.

Friday, April 23, 2010

Compression

Another thought related to the post below on compression: I'm not sure that the most compressed program is going to be the fastest in all cases. I don't have the requisite computer science knowledge to say for sure, but it seems that compressed computer programs need to be expanded before they are run, and this takes time. If a compressed program had to be expanded every time it was run, and had to compete with the already-expanded version of the program, then it would certainly be slower.

But then again, a program that contains is compressed, but expands to the larger program could be said to actually consist of both the compression and the expansion, and thus it is larger than the expansion alone.

Thursday, April 22, 2010

Simplicity in Epistemology

I got to make a pleasing contribution to my Epistemology class today, and some of my QA degree got called into service. Before class everyone was talking about how the reading was really tough (incomprehensibly so), and someone pointed out that "that guy" (me) was probably best suited to understand it. I was skeptical that this was true, but it actually worked out to be so in some cases.

An interesting point on compression: we were trying to ground Vitani and Li's claim that the most compressed (or compressible) description is most likely to be true (this is "Minimum Description Length" theory). Taking a page from Baum, I suggested:
  • Think of the phenomenon we're observing as a process with inputs and outputs, existing in an environment of finite resources.
  • Two processes may exist that have identical inputs and outputs, but which may differ in the process by which the output is produced.
  • If one process takes longer (ie: if the program is larger), then there will be proportionally more outputs produced by the faster process per unit of time, until the input resources are expended.
  • Therefore, there's a higher probability that the output we're observing has been produced by the simpler process.
Further (as Baum argues), when selection is added to this picture, the simpler process gets selected for and the more complicated one gets out-competed and dies out.

Later, We were trying to figure out why a model with fewer parameters gives larger priors. I pointed out that when you add parameters, you loose degrees of freedom, which is comparable to reducing the sample size, and thus increasing the variance. This (I guess?) would have the effect of reducing the prior. I might be blowing smoke.

Skipper was also intrigued by likelihood ratios: I explained that the "likelihood" of a model for a data set is the ratio of the product of the observed data (fit to the model) to the product of the theoretical values if the model was true. This is, at least, roughly how it works.

Broken brake cable

It never ends, it seems. This is the only cable I haven't yet replaced, and to be fair it was my fault. I apparently didn't put a locking washer on the nut that keeps the front break drum from rotating (and there's lots of force on that nut), and it came out. The result was a weird noise as the brake cable wrapped itself around the hub, and me being shocked when I pulled the lever and found it completely slack. Its surprising that it didn't bind up and pitch me over the handlebars, and for that I'm thankful.

I'm trying to think of what else could break. The only area I haven't overhauled or replaced is the gearbox; so the next trouble is probably there. I have felt the clutch slip a little bit when I really give it gas...

Update: whether or not there was a locking washer on the bolt (and I suspect there actually was) doesn't matter. The threads were stripped right out of the hole. So despite having procured a new cable this morning, I can't install it properly until I get the hole tapped and a bigger bolt put through it.

Wednesday, April 21, 2010

The Return of the King

My bike is, triumphantly, in front of my apartment again.

Several things, apparently, went wrong.

1. The gasket on the distributor cover had a gap in it, and this was causing a short, causing the plugs to not fire. See the post below.

2. When I left the ignition on for five minutes (without it running), it blew a fuse. I put two spares in the toolbox.

3. The sparkplugs were getting fouled; I got a spare and also put it in my toolbox.

4. Carbonized plugs are, evidently, the result of running too rich. I'm trying to figure out how to properly adjust the carbs now.

5. The bolt holding the gas tank to the frame came out.

6. The fuel hoses I installed get kinked when they get hot, as a result of the way the new gas tank makes them sit. Not sure if a longer hose will help, but I'm gonna try. Otherwise I'm just gonna have to modify the petcock on the tank somehow.

7. The lovely toaster tank doesn't have a tube connecting the two lobes of the tank to equalize the levels in them. So there can be lots of gas remaining in the left side of the tank, but if it doesn't slosh over the hump in the right side, the carbs will dry up. I might have to make a major modification to fix that.

Gasket

I fixed my distributor-cover electrical-shorting problem by making a
gasket out of the back cover of a notebook:

Thursday, April 15, 2010

A very breif victory

So I got the pants, gloves and helmet, and rode my bike back down to Clifton:

I had the pleasure of parking it in front of my house once:
And it broke down. I was riding it in traffic, trying to get the idle right (it was running really really high). I adjusted the idle stop for the right cylinder, it blew a bunch of white smoke, and then apparently stopped firing. I got it to start again and managed to get it to the College of Business, where its parked now. I'm afraid I might have to tear apart the engine again.

Local Music

Eclipse 'pry the best band I've seen live in Cincinnati. Click here to listen.

"Salsa with Cuban influence," as they say, and they blend Jazz with hip-hop vocals in a way that I find pleasing. It's what rap can be when its practitioners focus on rhythm and rhyme (and enunciation), when they have live virtuoso instrumentalists backing them up, and when they have lyrics with positive content.

Tuesday, April 13, 2010

Rachael and TJ, Sittin in a tree

K I S S I N G

Actually its just her in the tree. Its a bit small for the both of us, but I'm at least under it.

Saturday, April 3, 2010

Rachael and I queue in front of That to see Vampire weekend:

Vampire Weekend takes the stage:
the giant blond lady's powers are invoked:


Back in cincy, a musician gets a head massage before going on: