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0xDE
10 August 2015 @ 11:13 pm

I took a few photos on my recent trip to WADS, of the people at the conference and the scenery on the conference excursion. Below are the ones of individual people:

( The rest of the photos )

 
 
0xDE
08 August 2015 @ 08:52 pm
I just returned from Victoria, BC, where the University of Victoria (under the capable local organization of Ulrike Stege) was the host for WADS, the Symposium on Algorithms and Data Structures. (The acronym made more sense when it was calling itself a workshop.)

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0xDE
04 August 2015 @ 11:11 pm
If you've been paying any attention to my blog posts and other online activity, you probably know that I'm a huge fan of Wikipedia. I think it's a great way to communicate theoretical research to a wider audience, a great way to practice writing in a setting that encourages writing for readability, and a great place to publish survey-like material. Since I began editing Wikipedia in 2006, I have made over 90000 edits and created over 700 new articles (not counting redirects etc), most of them on mathematical subjects. I've also regularly been using collections of Wikipedia readings as textbooks in some of my classes for which there is no published text that matches the material I want to cover. I've encouraged others to contribute their expertise and will take the opportunity to do so again: Edit Wikipedia! Contribute your knowledge to the broader world!

But if you've read many Wikipedia article on mathematical subjects, you'll know that they can have a few issues. The content may sometimes be amateurish and topics may be missing, but those can be fixed with some effort. (Edit Wikipedia! Contribute your knowledge!) Another, more stubborn issue concerns the formatting of its mathematical equations.

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0xDE
02 August 2015 @ 10:39 pm
Street art? In Irvine? Apparently, now, the answer is yes. Local clothing manufacturer Tillys somehow persuaded the planning commission to allow them to commission Zio Ziegler (new Wikipedia article) to decorate one of their warehouses, right next to interstate 405, where approximately 240,000 daily drivers will see it.

You can't exactly stop on the freeway to take photos, but I found enough other more accessible vantage points to get a few shots:



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0xDE
27 July 2015 @ 11:55 pm
My daughter is doing a summer internship at the visual arts competition of the Orange County Fair: she helped bring in the submitted pictures, hung them, and assisted the judges, and now while the fair is on she gets to stand around telling people not to bring drinks into the exhibit. All very educational...

Anyway, this weekend we went to the fair ourselves, had Sara show us her favorite photos in the exhibit (as a staff member she got to assign three staff award ribbons to the entries), visited the ice sculptures, tasted some of the wines (my favorite: the Gold Hill 2011 El Dorado Zinfandel), ate greasy food on a stick (we did not try the deep-fried koolaid nor the caviar-encrusted twinkies), watched the pig races, etc. And of course, took plenty of photos.

The one below is of the stiltwalking leader of a steampunk band that passed us at one point during our visit:



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0xDE
25 July 2015 @ 12:24 am
One of my students, Will Devanny, is teaching a summer-session offering of our lower-division undergraduate data structures class. (My university forbids graduate students from being the instructor of record for classes during the regular term, despite allowing equally-qualified non-student lecturers, but encourages students to teach during the summer; don't ask me why.) Anyway, he asked his students the following question: Suppose you are given as input a sorted sequence of numbers. Describe an efficient algorithm for constructing a perfectly balanced binary search tree with these numbers as keys. (Here perfectly balanced means that the depths of the leaves of the tree are all within one of each other.)

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0xDE
07 July 2015 @ 09:38 pm

You're probably familiar with folding paper bags. You know, the small ones for lunches or the large ones for groceries? They have a triangular folding pattern on their sides that lets them either fold flat or open up into a brick shape. Five sides of the brick are covered by the paper of the bag, and the sixth top side makes an opening that you can put things into.

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0xDE
06 July 2015 @ 09:16 pm
There are a lot of ways of ordering points so that nearby points are likely to be nearby in the ordering; space-filling curves are one good example. But what if you want nearby points to be far apart in the ordering? In this case, a good choice is the farthest-first traversal (also known as greedy permutation), the subject of my latest preprint (with Sariel Har-Peled and Tasos Sidiropoulos, arXiv:1507.01555). This is an ordering of the given points determined by a greedy algorithm, in which each successive point is chosen to be as far as possible from all previously-chosen points.

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0xDE
04 July 2015 @ 10:57 pm
I'm in Mendocino once more for their July 4th parade. As usual it was an irreverent mixture of fire trucks, local businesses and politicians, theatre troupes, hippies, and protesters in a beautiful oceanside setting. Lots of fun, and I took lots of photos. Here's just one shot, of the start of the parade, where all the local fire departments (mostly volunteers) bring their trucks and set off their sirens.



The fog bank visible in the background is not a good omen for the success of tonight's fireworks show...
 
 
 
0xDE
30 June 2015 @ 06:11 pm
Although it only hints at the connection, one way of interpreting my latest preprint is about higher-dimensional graph drawings. The paper is "Track Layouts, Layered Path Decompositions, and Leveled Planarity" (with Bannister, Devanny, Dujmović, and Wood, arXiv:1506.09145).

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0xDE
29 June 2015 @ 06:55 pm
Here's another town in the Netherlands that I visited just before Computational Geometry Week: Thorn, also known as "the white village". The story goes that when Napoleon took over the Netherlands, he instituted a building tax based on how many windows each building had. So the villagers bricked up many of their windows and then, to make the change less obvious, whitewashed the buildings. The buildings are still painted white and give the place a distinctive look.

It's a small town, so not something that would likely fill a whole day of sightseeing, but very pretty. Behind the church we found an art gallery where an older man had put on a show of his art about trains, including paintings, prints based on old engineering drawings, and a giant model of the bridge over the river Kwai; it was the first day of the show and we were the first to visit.



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0xDE
28 June 2015 @ 02:51 pm
I arrived a day early in the Netherlands for Computational Geometry Week, to allow me longer to get used to the nine-hour time change. One of the things I did with the extra time was to visit Delft, one of many pretty Dutch canal cities, which turned out to be holding a fun flea market that day as well as some sort of children's marching band competition. I didn't take any photos of those, but I did get some from a tour of the Royal Delft Museum and Factory there. Royal Delft is probably best known for its ornamental blue-and-white painted plates, but I was more interested in their architectural ceramics:



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0xDE
27 June 2015 @ 03:33 pm
I just returned from visiting Eindhoven, the Netherlands, for Computational Geometry Week, including the 31st International Symposium on Computational Geometry, the 4th Annual Minisymposium on Computational Topology, the Workshop on Geometric Networks, the Workshop on Stochastic Geometry and Random Generation, the Workshop on Geometric Intersection Graphs, the Young Researchers Forum, and the CG Week Multimedia Exposition, almost all of which I attended pieces of (it was not possible to attend everything because SoCG had two parallel sessions and the workshops were run in parallel to each other).

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0xDE
16 June 2015 @ 08:30 pm
Somehow I seem to have two new papers online that I haven't mentioned here before.

Maximal SubsequencesCollapse )

Genus, Treewidth, and Local Crossing NumberCollapse )
 
 
 
0xDE
07 June 2015 @ 06:11 pm
I have another new preprint out this evening: "Metric Dimension Parameterized by Max Leaf Number", arXiv:1506.01749. The metric dimension of a graph is the minimum number of vertices you need to choose as landmarks so that all other vertices are uniquely determined by their distances to the landmarks.

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