SoCG 2008 Update

There’s only one session left of the second day of SoCG 2008 here at the University of Maryland in College Park. The temperature is close to 40 degrees C and it’s very humid so everyone stays inside in the air-conditioned building of the conference venue. As usual it’s hard to dress such that you’re not completely fried when you go outside, and such that you don’t freeze when you’re inside. The conference is taking place at the business school, I’m definitely not used to seeing stock tickers in computer labs – fun detail.

Bardia presented our paper, I/O-Efficient Algorithms for Computing Contours on a Terrain, as the very first day of the talk. The audience raised a couple of interesting points which I’m sure we’ll think more about after the conference.

The closes thing to a conference excursion was two busses that took us to Dupont Circle in downtown Washington, DC for dinner yesterday. I went to a Korean restaurant with a couple of people and had good Korean-style steak thingy, and I liked walking in the Dupont Circle area, which hadn’t explored on foot before.

Tonight is the conference banquet, that should be fun.

No Plans for August? Come to Denmark and Learn About Cache-Oblivious Algorithms

MADALGO is hosting a summer school on cache-oblivious algorithms in August this year. Here is the announcement: (Note that registration is free (!) and that the registration deadline is approaching)


Cache-oblivious algorithms are algorithms that are efficient on any
level of any memory hierarchy; they are basically algorithms developed
for a two-level memory model (I/O-model) but without using any
parameters describing the memory levels. Although it might seem hard to
design algorithms for a memory hierarchy without using any
hierarchy-specific parameters, many efficient cache-oblivious algorithms
and data structures have nevertheless been developed since the
cache-oblivious model was defined in the late 1990s. The goal of the
summer school is to provide an in-depth introduction to some of the key
issues in cache-oblivious algorithms and data structures.

The school will be taught by experts in the area of cache-oblivious
algorithms and data structures. The lecturers will include (more
lectures to be announced):

* Erik Demaine (MIT)
* Gerth S. Brodal (MADALGO)
* Norbert Zeh (Dalhousie University)

The summer school will take place on August 18-21, 2008 at Center for
Massive Data Algorithmics (MADALGO) in the Department of Computer
Science, University of Aarhus, Denmark.

The school is targeted at graduate students, as well as researchers
interested in an in-depth introduction to cache-oblivious algorithms.

The capacity of the summer school is limited. Prospective participants
should register using the online registration form available at as soon as possible. Registering
graduate students must also have their supervisor send a
letter confirming their graduate student status directly to; the subject line of the email should be
‘student_last_name/SS_2007/confirming’. Registration is on a
first-come-first-serve basis and will close on June 15, 2008.

Registration is free; handouts, coffee breaks, lunches and a dinner will
be provided by MADALGO and the University of Aarhus.

* Lars Arge (MADALGO, Aarhus)
* Gerth S. Brodal (MADALGO, Aarhus)
* Erik Demaine (MADALGO, MIT)
* Else Magård (MADALGO, Aarhus)

Center for MAssive Data ALGOrithmics is a major basic research center
funded by the Danish National Research Foundation. The center is located
at the Department of Computer Science, University of Aarhus, Denmark,
but also includes researchers at CSAIL, Massachusetts Institute of
Technology in the US, and at the Max Planck Institute for Informatics
and at Frankfurt University in Germany. The center covers all areas of
the design, analysis and implementation of algorithms and data
structures for processing massive data (interpreted broadly to cover
computations where data is large compared to the computational
resources), but with a main focus on I/O-efficient, cache-oblivious and
data stream algorithms.

SoCG 2008 Accepted Papers

The list of accepted papers for The 24th Annual ACM Symposium on Computational Geometry (SoCG) 2008 is out: (Hint, paper 40 looks good)

  1. Manor Mendel and Assaf Naor. Markov convexity and local rigidity of distorted metrics
  2. Noga Alon, Robert Berke, Maike Buchin, Kevin Buchin, Peter Csorba, Saswata Shannigrahi, Bettina Speckmann and Philipp Zumstein. Polychromatic Colorings of Plane Graphs
  3. Jinhee Chun, Matias Korman, Martin Nöllenburg and Takeshi Tokuyama. Consistent Digital Rays
  4. Eitan Yaffe and Dan Halperin. Approximating the Pathway Axis and the Persistence Diagram of a Collection of Balls in 3-Space
  5. Naoki Katoh and Shin-ichi Tanigawa. Fast Enumeration Algorithms for Non-crossing Geometric Graphs
  6. Ken Been, Martin N??llenburg, Sheung-Hung Poon and Alexander Wolff. Optimizing Active Ranges for Consistent Dynamic Map Labeling
  7. Hans Raj Tiwary and Khaled Elbassioni. On the Complexity of Checking Self-duality of Polytopes and its Relations to Vertex Enumeration and Graph Isomorphism
  8. Victor Chepoi, Feodor Dragan, Bertrand Estellon, Michel Habib and Yann Vaxes. Diameters, centers, and approximating trees of delta-hyperbolic geodesic spaces and graphs
  9. Esther Arkin, Joseph Mitchell and Valentin Polishchuk. Maximum Thick Paths in Static and Dynamic Environments
  10. Julien Demouth, Olivier Devillers, Marc Glisse and Xavier Goaoc. Helly-type theorems for approximate covering
  11. Sarit Buzaglo, Ron Holzman and Rom Pinchasi. On $k$-intersecting curves and related problems
  12. Mohammad Ali Abam, Mark de Berg and Joachim Gudmundsson. A Simple and Efficient Kinetic Spanner
  13. Frederic Chazal and Steve Oudot. Towards Persistence-Based Reconstruction in Euclidean Spaces
  14. Ken Clarkson. Tighter Bounds for Random Projections of Manifolds
  15. Krzysztof Onak and Anastasios Sidiropoulos. Circular Partitions with Applications to Visualization and Embeddings
  16. Bernard Chazelle and Wolfgang Mulzer. Markov Incremental Constructions
  17. Kenneth L. Clarkson and C. Seshadhri. Self-Improving Algorithms for Delaunay Triangulations
  18. Frederic Cazals, Aditya Parameswaran and Sylvain Pion. Robust construction of the three-dimensional flow complex
  19. Herbert Edelsbrunner, John Harer and Amit Patel. Reeb Spaces of Piecewise Linear Mappings
  20. Evangelia Pyrga and Saurabh Ray. New Existence Proofs for $\epsilon$-Nets
  21. Lars Arge, Gerth Stølting Brodal and S. Srinivasa Rao. External memory planar point location with logarithmic updates
  22. Eric Berberich, Michael Kerber and Michael Sagraloff. Exact Geometric-Topological Analysis of Algebraic Surfaces
  23. Misha Belkin, Jian Sun and Yusu Wang. Discrete Laplace Operator on Meshed Surfaces
  24. Olivier Devillers, Marc Glisse and Sylvain Lazard. Predicates for 3D visibility
  25. Luca Castelli Aleardi, Eric Fusy and Thomas Lewiner. Schnyder woods for higher genus triangulated surfaces
  26. Erin Chambers, Jeff Erickson and Pratik Worah. Testing Contractibility in Planar Rips Complexes
  27. Rado Fulek, Andreas Holmsen and J??nos Pach. Intersecting convex sets by rays
  28. Noga Alon, Dan Halperin, Oren Nechushtan and Micha Sharir. The Complexity of the Outer Face in Arrangements of Random Segments
  29. Maarten L??ffler and Jack Snoeyink. Delaunay triangulations of imprecise points in linear time after preprocessing
  30. Erin Chambers, Éric Colin de Verdière, Jeff Erickson, Sylvain Lazard, Francis Lazarus and Shripad Thite. Walking Your Dog in the Woods in Polynomial Time
  31. Jean-Daniel Boissonnat, Camille Wormser and Mariette Yvinec. Locally Uniform Anisotropic Meshing
  32. Adrian Dumitrescu, Micha Sharir and Csaba Toth. Extremal problems on triangle areas in two and three dimensions
  33. Timothy M. Chan. A (Slightly) Faster Algorithm for Klee's Measure Problem
  34. Timothy M. Chan. Dynamic Coresets
  35. Timothy M. Chan. On Levels in Arrangements of Curves, III: Further Improvements
  36. Minkyoung Cho and David Mount. Embedding and Similarity Search for Point Sets under Translation
  37. Jacob Fox and Janos Pach. Coloring K_k-free intersection graphs of geometric objects in the plane
  38. Timothy G. Abbott, Zachary Abel, David Charlton, Erik D. Demaine, Martin L. Demaine and Scott D. Kominers. Hinged Dissections Exist
  39. Vida Dujmovic, Ken-ichi Kawarabayashi, Bojan Mohar and David R. Wood. Improved upper bounds on the crossing number
  40. Pankaj Agarwal, Lars Arge, Thomas Mølhave and Bardia Sadri. I/O Efficient Algorithms for Computing Contour Lines on a Terrain
  41. Pankaj Agarwal, Bardia Sadri and Hai Yu. Untangling triangulations through local explorations
  42. Ileana Streinu and Louis Theran. Combinatorial Genericity and Minimal Rigidity

Election Day

I never made it to the consulate in Seattle in time to vote, pills unfortunately. I hope the right ones win. Anyways, stuff DR decided to open their online live-tv to non-danish computers for today only, so I am currently sitting in my office at Duke watching the online coverage of the election, yay :)

Election on online TV

We ordered some new machines the other day, four Dell XPS 720, two of those are in Denmark and the other two are currently in my office – look at these babies:

New Toys

Flight Log

This blog needs more random junk! Being a flight geek I decided to keep track of my flight history, so far 46 legs in 18 months (!). I wil try to keep the log updated – mostly for my own amusement.

It would also be cool to attach pictures to the different places as well, similar to Mihai’s picture page.

[Update]: Forgot trip to Waterloo in December, haven’t bought the tickets yet but it will probably raise the grand total to 50 flights in 18 months.

[Update 2]: Yay, Air Canada has direct flights from RDU to Toronto (YYZ).

Danish Election

There’s an election in Denmark in November and I am kinda bummed that I won’t be there to vote. This document at the website for the Danish embassy in Washington says that I can go to a Danish consulate or embassy and vote by mail, the deadline for doing this is November 6. According to this list, the closest official danish mission is in Atlanta, Georgia or Charleston South Carolina, but that’s still quite a drive and I won’t have time to go there before November 6. On the other hand, there’s a Danish consulate in Seattle, and I am flying to seattle on November 6. It’s a long flight, but due to the time diffence I am going to be arriving in the late afternoon (about 3pm) and the Danish consulate closes at 4pm – which means that if I don’t get delayed in flight and get a very fast cab from the airport, I might just make it.


I have not been very good at updating this blog lately, I personally blame the fact that I have both Facebook and IM accounts. It is more convenient for me to update my facebook status, so my facebook-friends get more updates than the readers of this blog.
Anyways, a fortnight ago I travelled to Eilat, Israel for the European Symposium on Algorithms (ESA). The conference hotel was situated right by the red sea and a few hundred meters from the Jordan-border and sported several swimming pools and bars.


View from my hotel room’s balcony.


The lagoon on the back side of the hotel, the mountains in the distance are in Jordan. Continue reading Israel

Noise Cancelling Headphones

I ended up buying a set of Sony MDR-NC60 at Circuit City here in Durham. So far I am very pleased with them, they come with airplane plugs and a handy bag and the sound quality is quite good. Furthemore, when the noise cancelling feature is turned on, the hum of A/C devices pretty much disappears, I am looking forward to see how effective they will be on airplanes. I constantly turn the volume up way to high on the crappy head phones that most airlines supply – hopefully I won’t have to do that with these.

Car Update

Lars and Henrik arrived 7 days ago have been visiting Duke the past week. Lars went home yesterday and Henrik is staying a week more. Yesterday Henrik and I went to Jiffy-Lube in Durham and I had my car inspected (it passed!) and got an oil change. I am now pretty much done with all the talks related to the car, find the only thing left is to send the old New Jersey plates back and to send my insurance company a copy of my registration.

I have a couple of lang-haul flights in the upcoming months (Seattle and Israel) and is currently seriously looking into noise canceling headphones. I tried a pair from Bose at an Apple Store in Raleigh two days ago and they were amazingly effective, pilule they would make for a great companion on flight and on the train when I get back home. Unfortunately the technology is quite pricey with the top-of-the-range Bose headphones leading the field at around 300 dollars. I am also considering getting one of the new 8 gig iPod nanos (yes I know, I said I would never get one of those, leave me alone!) to go with the head phones. The iPod is actually considerably _cheaper_ than the headphones.

If anyone has any headphone recommendations, please put them in the comments to this post. I have read this positive New York Times review of different types of headphones, the technology looks pretty mature.