Thursday 30 October 2014, 12:16
In January of 2011, I had recently arrived at the University of Manitoba
to work as a postdoc with Stephane Durocher. One of the first things he
asked me to do was find out how many cycles there are in an n-dimensional
hypercube graph, for general n. At the time, he and I both assumed that
that meant spending maybe half an hour in the library looking up the
Since then it's been more than three years; thousands of lines of
computer code and months of CPU time; we added two more co-authors; we
didn't solve the original problem, and didn't completely solve the
other problem that we ended up working on, either; but here's a journal
paper, anyway, and I think it's pretty interesting. The official definitive
version will be free to access until mid-December and then will go
behind Elsevier's paywall; the authors' accepted manuscript on
arXiv is permanently accessible.
Read the paper if you're interested in the math details; in this entry
I'm going to try to tell the story behind the paper, in relatively
non-mathematical terms. I'm hoping it'll be of interest to my Web log
readers and give you some idea, because I often get asked this, of what I
actually do at work.
Wednesday 15 October 2014, 11:49
Every time I think I've seen it all with regard to Danish excuses, this place
surprises me. Today's excuse is tzaraath.
Monday 6 October 2014, 12:26
Saturday 4 October 2014, 13:23
I've been in Denmark just over a month, and I'm pretty stressed. This
update is going to be somewhat disconnected. You can get some idea of what
my experience has been like by watching the famous Bank Account
Thursday 4 September 2014, 12:35
Denmark, being part of Europe, has a great deal of bureaucracy and many
rules. However, the Danes are not really rule-followers. That at least is
their reputation among people from other Nordic countries and I can see why.
This is a list of excuses I've heard from Danish people, mostly
government bureaucrats. All are genuine, though some have been paraphrased
from their more complicated original forms or to remove personal
information. The list will be periodically updated.
Thursday 4 September 2014, 12:32
As I start writing this, it's Thursday aboput 2pm in Copenhagen, and I am in
the waiting room at International House Copenhagen, waiting to apply for a
Central Persons Register (CPR) number. I have been in Denmark since Monday
Thursday 28 August 2014, 18:59
I don't think I have officially mentioned this here on my Web log yet,
but here it is: I am moving to Denmark to work as a postdoc in the
Scaleable Similarity Search project at the IT University of Copenhagen.
This is a one-year temporary position with a possible renewal for a second
As I type this, I am in my apartment in Winnipeg, sitting on top of my
modular synthesizer in its Pelican case because that is the closest thing to
furniture that hasn't been taken away by either the movers or Goodwill.
Sunday 17 August 2014, 16:26
I have just posted Tsukurimashou
0.9, the latest version of my Japanese-language font project.
After almost a year in development since the last version, this one contains
1754 kanji, including all through Grade Four and 100 from Grade Five (a
little more than half of the 185 assigned to that grade). This version also
includes extensive infrastructure changes, most notably a bundled
interpreter for the FontForge native scripting language, intended to provide
insurance of future support as mainline FontForge moves further and further
away from that language.
The future of Tsukurimashou development may be tangled, as my commitments
and priorities change with my upcoming move to Denmark. This 0.9 release was
produced in a bit of a rush to get something out the door before I pack up
my computer for shipment. I don't know when I will next get a change to
work on it more, but that will be at least two months from now. You can do
your bit to support continued work on Tsukurimashou by building it, using
it, and above all by writing about it. What the project needs most of all
Sunday 20 July 2014, 20:20
The Apollo moon landings were fake.
I don't mean that they did not occur - it was before I was born, but it
seems clear that men did at one time walk on the Moon. There are too many
independent confirmations of that for it to be in any reasonable doubt.
However, the Apollo Moon landings occurred under false pretences. The
story told about the factual events, both at the time and now, was and is a
dishonest story, carefully constructed to further the goals of the US
government and certain other powerful forces.
Sunday 20 April 2014, 16:52
In my last posting I
described getting Slackware ARM to boot headless on the ODROID U3
single-board computer, and I said that the next step would be to try to make
it handle ungraceful shutdown (power loss) better. I plan to put this board
into a Eurorack synthesizer module with no easy access to the microHDMI monitor
connection, and SSH over the Ethernet connection as the only access to
administrative functions. If, when the power is pulled on it, it comes up
on next boot in a state where it requires console interaction to do a step
like checking the filesystem before it will accept SSH connections, that is
a disaster; I'd have to disassemble the whole module to extract the
microSDMI card and replace the OS image. To be useful, the ODROID
must be guaranteed or almost guaranteed to survive a power drop
and come up SSH-able on the next boot. Ideally, I want pulling the plug
on it with no shutdown formalities to be the normal expected way of shutting
it down too, not just an error condition from which it can recover. A good
journalling filesystem can increase the chance of recovery from occasional
accidental power drops, but I think the only way to make routine
non-accidental power drops safe is to keep the filesystem mounted read-only
- which might be desirable anyway, to reduce wear on the flash memory
and prevent its being corrupted by other kinds of accidents. So this
posting is about my experiences configuring Slackware ARM on the ODROID U3
to keep its root filesystem read-only.