A picture taken a few years ago -
now I have much smaller glasses...;
"Barequet" is the biblic word for
emerald (Be3Al2(SiO3)6::Cr) !
barequet at cs dot technion dot ac dot il
Help!
|
A picture taken a few years ago - now I have much smaller glasses...; "Barequet" is the biblic word for emerald (Be3Al2(SiO3)6::Cr) ! |
barequet at cs dot technion dot ac dot il
Help! |
|
| Associate Professor at the
Dept. of Computer Science,
Technion---Israel Institute of Technology Head of the CGGC (Center for Graphics and Geometric Computing) since October 2001 [CGGC seminar program; brochure; articles: Technion Focus (1/2002), Technion Magazine (3/2002), CS Homepage Magazine (2/2009)] |
|
(23/MAY/13)
λ > 4
(Joint project with Günter Rote from Freie
Universität Berlin and my M.Sc. student Mira Shalah.)
On Sunday, May 19, 2013, 20:25 Germany time (21:25 Israel time), the
supercomputer DL980 of the "HPI (Hasso Plattner Institut) Future
SOC Lab" in Potsdam, Germany, computed the new lower bound 4.0009... on
λ, the asymptotic growth constant of polyominoes on the planar
square lattice.
(Specifically, this number is a lower bound on λ27,
the growth constant of polyominoes on a twisted cylinder of width 27,
which itself is a lower bound on λ.)
Our program continued to run for a few more days, resulting in the final
lower bound 4.002537727 obtained today
around 17:30.
The computation was peformed on 64 cores (128 virtual cores) with a total
of 2 TB of main memory (RAM).
The fact that we performed the computations with 32-digit
floating-point numbers does not imply that numerical
errors can be too large to nullify our result.
Our computed number is an eigenvalue of a huge integer matrix, for which
we have a witness vector that is a good approximation of the eigenvector
corresponding to λ27.
This vector proves rigorous bounds on the true eigenvalue with numerical
errors whose magnitude is comparable with the accuracy of floating-point
numbers, much smaller than the gap we opened above 4.
=====================================================================
(23/NOV/12) Once again, the Technion CS team, Idan Elad, Olivier Hofman, and Mike Harris, with its coach Noa Korner and under my virtual supervision, performed nicely, winning this time a bronze medal (12th place) in the prestigious ACM/ICPC contest (Southwestern Europe region) held in November 18, 2012 in Valencia, Spain.
(22/NOV/10) The Technion CS team, Shahar Papini, Yaniv Sabo, and Carmi Grushko, with its coach Kolman Vornovitsky and under my supervision, won a gold medal (2nd place) in the prestigious ACM/ICPC contest (Southwestern Europe region) held in November 21, 2010 in Madrid, Spain. (Shahar almost did not compete since he lost both his passport and his contest badge. Worldwide efforts to restore both items were successful.)
(04/MAR/09) The Technion awarded me the Henri Taub prize for academic excellence for a few polyomino and polycube-related works. (The background of the picture in the above link is completely unrelated to the things I do. 8-)
Just want to be a CGGC student and then decide? Click
Here.
Would like to consider a thesis topic in Computational Geometry? Take my
Computational Geometry
course and send me a
message!
Here is a nice research problem for a thesis: Read
this paper (journal #26) and rethink about
the 3D case. Can it be improved to Ω(1/n³) by sharpening
the argument for the inner-most cylinder?
For perspective,
here is
(completely out of context!) how Eli O'Hana was quoted in Yediot Akhronot in
an interview in May 1999.
Computational geometry
Graph theory and combinatorics
Discrete mathematics
Geometric and solid modeling
Geometric algorithms for medical imaging
Geometric algorithms for computer graphics |
 |
Polyominoes and polycubes:
Running time of Jensen's Algorithm
λ (Klarner's constants) ≥ 3.9801
Redelmeier's algorithm on any lattice
Redelmeier's algorithm without the dimensionality curse
Formulas enumerating polycubes
Tree-like convex polyominoes
Exact formular for DX(n,n-3)
Object reconstruction from slices:
Geometric-hashing algorithm
Context-enabled interpolation
Smooth blending of slices
Straight-skeleton algorithm
Matability of polygons
Moving polygons around
Nonplanar interpolation
Multicolor interpolation
My
electronic collection of human organs and digital terrains
(in polygonal-slices format), and related software
My
partial surface matching and object registration software
My
polyhedral environment and database software (DCEL)
Software for
approximating the minimum-volume bounding box of a spatial point
set (with Sariel Har-Peled) 
Computational Geometry (236719,
announcement):
Project in Copmutational Geometry (236729):
Discrete Algorithmic Geometry (238739):
Advanced Seminar in Geometric Computing:
Computer Graphics 1 (234325):
Introduction to System Programming (234122):
CS, Tel Aviv University
(Tel Aviv, Israel, 1991-96)
CS, Johns Hopkins University
(Baltimore, MD, 1996-98)
CS, Tufts University
(Medford, MA, 2009-10)
Office address:
Dept. of Computer Science
(New Taub bldg., fl. 4, rm. 428)
Technion---Israel Inst. of Technology
Haifa 32000
Israel
+972 (4) 829-3219
(ask Sigal below)
(center) +972 (4) 829-5538
(dept.) +972 (4) 829-3900
barequet@cs.technion.ac.il
http://www.cs.technion.ac.il/~barequet
CGGC administrative assistant:
Sigal Zemach
New Taub bldg., fl. 4, rm. 427
phone: +972 (4) 829-4906;
fax: +972 (4) 829-5538
sigal@cs.technion.ac.il
View in and from the Technion:
| The new Taub building, hosting the department of computer science: (Click on the picture to see it full sized) |
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| When the visibility is perfect, this is how the Hermon mountain
(60 miles [96.5 KM] from Haifa) is seen from my office: (Click on the picture to see the full sight [Dani B., 07/01/2003], and a new picture shot ten years later [Mira S., 29/01/2013]) |
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