The 2019 Iriomote Workshop on Parallel Tree Search and Discrete Optimization
A workshop held from May 20, 2019 until May 24, 2019 in Iriomote, Japan.


A small workshop will be held at the Villa Iriomote (西表島のリゾートヴィラ) in Iriomote, Japan, from May 20, 2019 until May 24, 2019. This is the second workshop, after a first successful meeting in May 2017.

There will be talks by three speakers:

The workshop is part of a five-year JSPS project entitled Large scale parallelization for geometric computation with mathematical programming applications (幾何計算のための大規模並列化と数理計画法への応用). That project is summarized as follows: Most research in algorithms since the 1970s has been for single processor machines, resulting in a vast amount of sophisticated and robust software. Unfortunately most of this software profits very little when run on the now prevalent multiprocessor hardware. The redesign and reimplementation of all this software will be an extremely time consuming and expensive task. The purpose of this research is to efficiently parallelize certain algorithms without any essential change to their existing implementation. This is achieved by adding parallelization as a wrapper to the existing code. This technique will be applied to tree search algorithms used in geometric computation, discrete optimization, AI and machine learning.


  • Monday May 20, 2019: Arrival at Villa Iriomote.
  • Monday May 20, 2019-Friday May 24, 2019: Workshop. We will have talks in the morning (Villa Iriomote conference room, 10-12am) by the main speakers, and open problem and work sessions in the afternoons. The topics of the talks will be as follows:
    • May 20-May 21 (David Avis). Algorithms for approximating the size of Galton-Watson trees.
    • May 22 (Luc Devroye). Tree size estimation by random sampling.
    • May 23 (William Cook). Computation of the Beardwood-Halton-Hammersley constant for random TSP problems.
  • Friday, May 24, 2019: Departure of all participants.


The meeting is organized by David Avis (Graduate School of Informatics, Kyoto University, Kyoto, Japan).


All participants are responsible for their own meals. Near the workshop hotel, one can dine at Kitchen Inaba ($$) and Shima Italian En ($$), or visit one of several local noodle restaurants ($).


The workshop takes place at Villa Iriomote in Uehara, which is located on the island of Iriomote, Japan.

Iriomote can be reached by a brief boat transfer from Ishigaki Jima via the ports of Ohara or Uehara. From the port of Uehara, there are taxis, or one can walk (ca. 10 minutes). From Ohara, one must take a bus which costs about 1000 yen. Ishigaki has many daily flights to Osaka and Tokyo.

About Iriomote

Iriomote (西表島), like the rest of Japan, is safe. In May, the temperature is quite pleasant, ca. 25 degrees, thanks to the a cooling ocean breeze.


Participants should find their own accommodation. Besides Villa Iriomote in Uehara, there is Hotel Nirakanai (ホテルニラカナイ小浜島), a luxury hotel. Other hotels are available in the port of Ishigaki such as Hotel East China Sea (ホテルイーストチャイナシー <石垣島>).