Some thoughts for 2015

Thursday 1 January 2015, 04:38

On this first day of 2015 I'm writing down some things that are important and that I wish people around me would know. There's nothing here that I haven't said before. My usual pattern is to say something and treat it as settled, because I expect everyone present at the time to remember it once they've been told. But not all of my friends have been paying attention to all of my writings for all of the decades I have been writing, and maybe at this time some repetition is appropriate. I wish I could have ten thousand readers for this and for all of my important postings. I may be lucky to get as many as ten readers. But if nothing else, the exercise of choosing what I want to say today is of some use to me personally, whether anybody reads it or not.

Matthew, Rued Langgaards Vej 7, versus the Appliances

Wednesday 31 December 2014, 13:16

It's New Year's Eve in Copenhagen, and time for another update.

lilypond-bookとLaTeXで音楽の植字

Friday 5 December 2014, 23:15

数学と理学ではLaTeXが有名です。 論文を書ければいつもLaTeXを使っています。 でもLaTeXではいろいろな文書ができます。 今日LaTeXとlilypond-bookで音楽の書くことを見ましょう。

[音楽]

これはTeX & LaTeX Advent Calendar 2014に僕の寄贈です。

New apartment

Sunday 2 November 2014, 02:07

As I start writing this, it is the evening of November 1 and I am sitting in my new apartment on Hallandsgade, Amagerbro, Copenhagen. It'll probably be the 2nd before I can post it, because I don't have the Net here. It sure looks like Rabbi Schlomo Yitschaki was dead right about the tzaraath of houses. Now I kind of want to read the rest of his many volumes of commentaries on Jewish religious law.

Cycle-maximal triangle-free graphs

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 answer.

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.

Days since last Biblical plague: 0

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.

False negative

Monday 6 October 2014, 12:26

I. Fukurou

Bank Account Man

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 Man commercial.

The Danish excuse list

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 received 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.

A few days in Denmark

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 morning.