I went to see the launch of Space Shuttle Discovery in Florida a couple of weeks ago and am finally getting around to posting a few pictures. The actual launch happened just before dawn, so the it was mostly a big fireball in an otherwise dark sky, but it was awesome and my camera was able to pull out some dawn light a few minutes after launch (that's Discovery in the photo above about 300 miles downrange from Cape Canaveral). The shuttle is scheduled to land back in Florida tomorrow morning, and with only three flights left I'm really glad I got to witness a launch before the shuttle program ends.

Jesse presenting our Billion Triples Challenge work

Our work on RDF querying on supercomputers was recieved with much interest at the SSWS workshop. Lots of good questions were asked about the approach, and I hope I provided reasonable answers to them (though I think I could have done a better job in presenting the techniques to avoid some of the resulting confusion). The big news was that our Semantic Web Challenge entry (combining the parallel RDF query work, Jesse's parallel RDFS materialization work, and Medha's BitMat work) won in the Billion Triples track.

Jesse and I had some good conversations with Jacopo Urbani about his MapReduce-based reasoning system, its similarity to Jesse's reasoning work, and the overlap with the parallel query answering work (in the context of extending their systems to handle more expressive reasoning).

Members of the SPARQL working group had what I thought was a good panel Q&A at ISWC about what's coming in SPARQL 1.1. There was some good input (and criticism) of what we've got so far, and I hope we can follow up on many of the points made including the issues of efficient federated querying and atomicity versus full ACID trasactions (we discussed some of these issues at the meeting in Santa Clara).

The RDF indexing in Parliament (also presented at SSWS) looked interesting (especially the "average case analysis" that explains some of the tradeoffs of the design and why the design is good for many real-world datasets). Unfortunately, the SSWS proceedings seem to link mistakenly to a draft version of the paper. I've put some more thoughts on Parliament and its impact on our clustered RDF query engine on the Tetherless World blog: Parliament, storage density, and napkin math.

Golden Gate Bridge

Leigh Dodds produced a good looking vocabulary at VoCamp DC for Describing SPARQL Extension Functions. Seems like it would mesh nicely with the SPARQL service descriptions we're working on for SPARQL 1.1.

Expressing Statistics with RDF does a nice job of explaining how to use the SCOVO vocabulary to describe statistical data. I've been using SCOVO to encode statistical descriptions for the data.gov datasets with some success (though I hear the voiD folks are working on a less verbose way to do dataset descriptions).

Silk looks like a great tool to do linking between datasets, and something I hope we can look at for the data.gov RDF work.

Finally, while sitting in on the SPARQL meeting in Santa Clara, Dave Beckett designed a very nice diagram explaining the SPARQL 1.1 Query Execution Sequence. It captures the conceptual ordering of the operations involved in a SPARQL 1.1 query (including aggregates) and I assume maps nicely to many actual implementation (certainly it does to mine).

1. No Apple laptop should ever be put to sleep while not connected to an external power source.
2. No Macintosh computer will sleep if any running application is trying to access the network.

After explaining my problems (which included the sleep issue, iSync [which I haven't seen since 10.4!] starting every few minutes, and screen artifacts), the "genius" tole me that I could damage my laptop by letting it sleep without the external power source plugged in. Putting that aside for now, and insisting that that wasn't my problem, he had me boot the system and immediately upon seeing several menu bar accessories and many icons on the desktop immediately told me that I had lots of "third party software" installed, that much of it was probably incompatible with Snow Leopard, and that it wasn't his job to troubleshoot that sort of thing for me. He speculated that VMWare Fusion (which he referred to as Parallels) was causing the problem, but couldn't (or wouldn't) make an attempt to find out if VMWare Fusion was known to cause problems in Snow Leopard.

After pressing hard about not wanting to just be told to go home and make sure all my applications were compatible with Snow Leopard only to discover it was a deeper problem, he gave in and rebooted my system in safe mode. The sleep problem persisted. He then plugged in an external disk and boot the system into what I believe was Snow Leopard (but which he referred to as 10.5) and the sleep problem disappeared.

At this point, he suggested that it was clearly a problem with my "third party applications" (a term he used many, many times as if to suggest that I was somehow out of the mainstream by running any applications not provided by Apple, and the use of which made my seeking technical support a waste of his time), and that a clean install was the solution. He continued to tell me that my laptop wouldn't ever sleep if any running application were "trying to access the network." To this last point I told him he was wrong, but he insisted that any application trying to access the network would wake the computer from sleep. Clearly trying to argue this point wasn't a good use of my time.

As a final attempt to make his point, he started Activity Monitor, and sat watching the CPU usage graph for a couple of minutes and told me that "there's a lot of programs running for an idle system." I resorted the process list by CPU usage and pointed out that the only processes which were actively running (and not sleeping) were mdworker, activitymonitord, and kernel_task, all Apple-provided processes. There was not real response to this, he asked what Tweetie was, and then reiterated that I was just going to have to perform a clean install.

By this point I wasn't confident that my iSync or screen artifact issues could be resolved by spending any more time at the genius bar. So for the time being, I'm stuck having to turn my computer off completely any time I need put it away from more than a few minutes, stuck having to dismiss iSync from trying to connect to a mobile phone which I haven't used in years, and dreading the reappearance of screen artifacts. This whole experience has soured me a bit on the Genius Bar. I've had such great experiences in the past, making this one all the more surprising and frustrating.

The Pirate Party says music and movies should be freely shared on the Web. Copyright laws should be rewritten, and the current patent system scrapped.

I'm sympathetic to wanting to change copyright laws and the patent system, but the Marketplace piece ended up sounding like these were secondary issues to wanting to be able to download free media and continue to make use of The Pirate Bay. Is this just bad reporting? Is the Pirate Party actually a civil rights party (as claimed), with those interviewed just making it sound like a party devoted entirely to pirating legitimately copyrighted media?

It's been a busy semester, which is now thankfully over. Since classes ended a few weeks ago I've remained busy, not only with research but also some travel and personal stuff.

Across the Charles

I went down to MIT for a W3C SPARQL meeting, meeting a lot of SPARQL people in person for the first time, and trying to avoid being attacked by the numerous robots that were patrolling outside our conference room (it's a wonder we got anything done with all the robots around the CSAIL lab). While in Cambridge, I stayed with Kabir for a couple nights, enjoying the awesome view of Boston and the Charles river from his apartment.

Red Tulips

After returning from Cambridge two weeks ago, Kat and I went to the Albany Tulip Festival and saw some nice tulips before it started pouring rain. It was nice, but the flowers seemed a bit past their prime by the festival (last year's timing worked out much better).

Buffalo

This past weekend, we drove out to Buffalo to spend the weekend with Karie. We had an amazingly full weekend, getting some great food (vegan buffalo "wings"!), drinks, waded out into Lake Erie from a secluded beach in Canada, and went to Niagara Falls (where there were much nicer tulips than in Albany).

Niagara Falls

More photos on Flickr of Buffalo and the Tulip Festival.

• SPARQL syntax extensions:
  • Support for UNSAID keyword, allowing much simpler syntax for queries with negation.
  • Support for FeDeRate BINDINGS syntax, generalizing the ability to pre-bind certain variables.
• The new (fairly rudimentary) cost model code will give significant speedup on some queries.
• The use of proper query plan objects allows queries to be built programmatically (a feature requested by KjetilK).

The new version, 2.100, is available from CPAN, and ongoing development is available from github.

But the other day, I noticed this:

Something has gone dreadfully wrong. How in the world did iTunes end up thinking this song (which I bought through the iTunes store!) is located in my Aperture library‽ What could have possibly caused this? Utterly baffling.

Wonderfully sleek, it summarizes my travels from last year, pulling photos from Flickr for the highlighted cities. I just wish there was some detail for all the cities.

Dopplr says my travel was responsible for 7.23 tonnes of CO₂. Not as much as I would have guessed, but still an uncomfortably large number. Hopefully visualizing this data helps me to keep the carbon emissions in mind when considering future travel -- something we should all try to reduce.

Wishing everyone happy holidays and a great new year.