Professor of Computer Science at UC Irvine, researching graph algorithms and computational geometry. Wikipedian. Amateur photographer. Father of two.
0xDE's Latest Posts
In my new Wikipedia article on the queue number of graphs, the binary de Bruijn graphs form an important family of examples. These are 4-regular graphs with one vertex for every n-bit binary string, and with an edge from every string of the form 0s or 1s to s0 or s1. I posted about them here several years ago, with the following drawing, which can be interpreted as a 2-queue drawing with one queue for the edges that wrap around the left side and another for the edges that wrap around the […]
A broken pane in the main stairwell of my department's building (maybe a bird strike?) gave me a chance to play with the geometry of shattered glass.( The rest of the photos )
The Schmidt arrangement, triangular rosettes of circles from number theory (G+)Brückner, Vielecke und Vielflache (1900), with a tumblr post of some stellated polyhedra photographed in the book (G+)$1000 prize for solving open problems in OEIS (G+)MAA celebrates Women's History Month (G+)Tensegrity robot video (G+)Mini-biographies of five women scientists (G+)Numberphile video on the diversity of human natural-language number systems (G+)Interactive 3d fractal fly-through (G+)Yet more […]
I was in Barbados last week for the Third Annual Workshop on Geometry and Graphs. This time, unlike my visit last year, I remembered to bring my camera.( Many more photos, not all by me )
Franz Brandenburg, Andreas Gleißner, and Andreas Hofmeier have a 2013 paper that considers the following problem: given a finite partial order P and a permutation π of the same set, find the nearest neighbor to π among the linear extensions of P. Here "nearest" means minimizing the Kendall tau distance (number of inversions) between π and the chosen linear extension. Or, to put it another way: you are given a directed acyclic graph whose vertices are tagged with distinct numbers, […]
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