Pasky’s Log

Readers of this blog should be already a little bit familiar with the Ailao brand, which we use for spinning off and commercialization of our academic research. Originally, Ailao was all about text and question answering, but there was always the theme of dealing with unstructured data in general.

Nowadays, Ailao is not just me (Petr BaudiÅ¡) anymore – but a partnership with Tomáš Gogár and Tomáš Tunys, fellow PhD students! And we are widening our breadth to cover documents in general, developing a machine learning computational platform Ailao Brain (just a codename!) as well as working hard on some exciting end-user products. We are also working on a prettier website (including a new look for this blog) and many other things, but more on that soon.

What I wanted to point out is our talk at Machine Learning Meetups Prague. The talk itself (video) is in Czech, but you can enjoy at least our English slides on our bleeding edge technology research (webpage information extraction and text understanding). Stay tuned for more!

At our hackerspace brmlab, one of the things we do is picking up landed weather sondes. In short, fun hardware literally falling off the sky, several times a day, every day. These are stratospheric balloons used for weather data prediction, launched from various sites, that reach the 35km altitude, then the balloon bursts and it lands back on the ground at a random location. At the whole time, it transmits its current GPS coordinates via radio, making this a rather exciting sub-class of geocaching.

As a simple hack today (idea by chido), I created a simple script sonde.sh that is designed to be run three times a day, runs sonde trajectory prediction (a predict.habhub.org service – example) and if the sonde is predicted to land in a certain radius, reports that with a link to the prediction. By default, it is connected to jendabot, one of our brmlab IRC robotic minions, written in an appealingly crazy way as a collection of bash scripts.

So, thanks to very helpful Rickta59 on #43oh IRC channel, I got my Launchpad v1.5 serial communication working. The key piece of information I was missing:

This is even drawn on the board, but it just didn’t occur to me that I need to do this simple thing. Most examples seem to use hardware UART, and Energia Serial class also uses hardware UART.

It is still very flaky:

• For the first ten seconds, communication is impossible. Wait for timeout messages to appear in dmesg, then you can start communication.
• When the board is sending data, something must be reading them on the host side. If not, the driver collapses and you need to replug the device.
• The latter might be circumvented by direct USB communication without involving the tty driver.

So, it is rather fragile, but usable! Let’s enjoy our Launchpads for projects where this is not a big issue…

Just a quick note – at the beginning of August, I have submitted my master thesis, titled Information Sharing in MCTS. MCTS means Monte Carlo Tree Search and it is a powerful technique for finding moves in games with large state space and difficult evaluation functions, such as Go.

The thesis presents the modern Computer Go techniques and open problems, my (not too weak) Go-playing program Pachi and some modest improvements of the MCTS algorithms. It might make a good introduction to state-of-art Computer Go.

Couple of things to blog about accumulated again, so I guess I will be posting bunch of articles soon. For such a long gap, a general update is in order, I suppose.

Aside of my studies, continuous MCTS (Go) research, grinding away on random glibc bugs and such, I most notably got involved in brmlab this summer – the Prague hackerspace. We got a pretty thriving community there now, with various cool events, a lot of great projects (I’m involved in quite a few), and so on!

Well, I wanted to mention more, but I can’t remember it right now. I suppose it will just come together. Oh, and seeing my last post – I have a new bike, this time with insurance. ;-)

So, just after I wrote about biking in Prague, my bike got stolen… :-(

I was used to leave my bike standing around (locked by the standard cheap-ish wire lock) quite a lot, even at a relatively deserted places at night, and noone bothered to stole even the snap-on lights, so I was quite delighted about safety in Prague… yesterday, I rode to do some shopping at the local supermarket and locked my bike in front of the supermarket. When I came back, there was only the snapped lock lying at the ground where there used to be my bike. Noone saw anything, unsurprisingly.

This has quite robbed me of my naivity; I’m intending not to give up on daily utility biking (which does inevitably involve leaving the bike outdoor at various places), but I just wish I’d have read the PrahouNaKole guide.

Anyone knows a good shop with used bikes in Prague, preferrably with low percentage of stolen bikes? My first bike has cost about 9.5k with all accessories, I’d prefer not to go over 4.5k with my second one.

About two months ago, I have finally bought myself a bike and started riding semi-regularly to work – the round trip amounts to about 17km daily, which is a decent workout already. (When it will start feeling too easy, I will just ride faster. ;-)

I was not very keen on this for a long time since Prague is not an overly bike-friendly city and the only time I can really give the bike-riding is riding to work (in the city center), since so many things already chew on my free time. You don’t really see many bike corridors and bike lanes in Prague.

However, I have given this some more serious thought at the beginning of Spring, and it turned out that things aren’t nearly as bad as it seemed and it is in fact possible to find very decent routes.

My priorities were:

• No long/steep climbs. My stamina is not up to it so far.
• Absolutely no riding with many / fast going cars. I value my life.

…and I live in Letnany and work at Mala Strana. Hmm?

It turned out that it is possible to ride this route while avoiding _any_ busy roads! The indispensable resource here is the prahounakole.cz map – it is not an official resource but a community map showing not only official bike roads, but also good routes over normal roads, etc. with a very good organization so it is really easy to plan a route between any two points in Prague.

One good rule of thumb is “get to Vltava” – along most of the river, there are fine bike roads and you may spend the most of your trip there; the only problematic point is the historic center. Other than that, it turns out that where there is busy road, that frequently also means that the sidewalk is completely deserted and can be easily used. (If the sidewalk does not tend to be deserted, it is of course not a good practice at all to use it.) Putting these two together, it’s almost painless to go from Letnany to Mala Strana and back.

(I use the cunning A262 to get from Letnany to Vysocany extremely fast, then join the bike route A26 to get to Vltava and go by A2 all the way to Palachovo namesti. The only part of the way where I have to go with many cars is over the bridge then.) (An alternate route is over Strizkov, but right at the beginning there is an annoying killer climb to get over the highway, and the extremely busy A27->A2 crossroad is basically impossible to cross safely. A262 is *much* better even though it involves one slightly annoying road crossing too.)

(To get back, I don’t use the same route as my stamina is not yet up to climbing all the way back to Letnany. ;-) So I go along the other side of Vltava, on Nabrezi kapitana Jarose. There is no bike route there, but except a tourist bus stop at one point, the sidewalks are completely deserted, and then A1 moves to the sidewalks as well anyway; at Holesovicka trznice, it’s best to turn to A151 (on sidewalks too), suffer two road crossings, and then get quickly to Nadrazi Holesovice – the subway will get me back to Letnany then.)

Hope this helps someone. :)