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Office
625 Soda Hall
Computer Science Division
University of California at Berkeley
Berkeley, California 94720-1776
(510) 642-3936 [(510) NICE ZEN]
Fax: (510) 642-3962
Home
965 Sutter Street #815
San Francisco, California 94109-6082
Outside of email, your best shot at contacting me is to try my office
between 5 pm and midnight on Monday, Wednesday, Thursday, or Friday,
in person or by phone, except during my
mesh generation class, which takes place
Mondays and Wednesdays, 5:30-7:00 pm.
(I do not come to campus or read email on Tuesdays.)
Those are the ideal times to ask me about
research, coursework, or anything else.
Sadly, Soda Hall is locked after 6:30, so call my office
if you want to visit and don't have a keycard.
While you're by, ask me to make a pot of tea.
I get teas from Upton Tea Imports,
a first-rate importer in Massachusetts,
and I enjoy introducing people to the good stuff.
Mornings I sleep and afternoons I shuttle from meeting to meeting.
Attempts to phone me during that period are futile.
TRIANGLE.
A production-quality C program for
two-dimensional constrained Delaunay triangulation and quality mesh generation.
See the
Triangle page
to obtain the source code or for hypertext instructions.
I expect to release its three-dimensional successor, Pyramid,
in the near future.
The algorithms behind Triangle and Pyramid are discussed in my dissertation
and in several other papers on my
Papers page.
EXACT ARITHMETIC AND ROBUST
GEOMETRIC PREDICATES.
I've written a set of fast routines for exact floating-point
addition and multiplication, which I've used to create
fast correct geometric predicates, namely the two- and three-dimensional
orientation and incircle tests.
These predicates are used to make the Delaunay triangulation routines
in Triangle and Pyramid robust against roundoff error.
See my
Robust Predicates page for more information, for papers,
or to obtain the C source code.
RESEARCH OVERVIEW.
Here's a self-contained summary of some of my research.
This is the fastest way to learn a bit about my work.
THREE SINS OF AUTHORS IN
COMPUTER SCIENCE AND MATH.
A short crotchety essay that will improve your technical writing,
or annoy you trying.
You won't find these sins decried in the usual books of writing advice.
While you're at it, you might be interested in my (less snarky) advice on
Giving an Academic
Talk.
Projects
QUAKE.
The Quake Project is a multidisciplinary Grand Challenge Application
Group studying ground motion in large basins during strong earthquakes,
with the goal of characterizing the seismic response of the Los Angeles basin.
We've created some of the largest unstructured finite element
simulations ever performed.
ARCHIMEDES.
Our secret to producing such huge unstructured simulations?
With the collaboration of David O'Hallaron, I've written
Archimedes,
a chain of tools for automating the construction of general-purpose
finite element simulations on parallel computers.
CS 274: COMPUTATIONAL GEOMETRY(Autumn 2006,
Spring 2005,
Spring 2003).
Geometric algorithms, analyses, and applications.
Polygons, polytopes, triangulations, planar and spatial subdivisions,
convex hulls, halfspace intersections, Voronoi diagrams,
Delaunay triangulations, arrangements of lines and hyperplanes.
Geometric queries (databases, point location), binary space partitions,
robot motion planning, cartography, solid modeling,
small-dimensional linear programming, and more.
BRYAN KLINGNER
is studying tetrahedral mesh improvement algorithms and
physical simulations with dynamically changing geometry.
RAVIKRISHNA KOLLURI
in December 2005 completed his Ph.D. on surface reconstruction algorithms,
including spectral surface reconstruction, scan registration,
moving least squares interpolation for generating implicit surfaces,
and the very cool
Power
Crust.
He now works at Google.
FRANÇOIS LABELLE
in August 2007 completed his Ph.D. on
tetrahedral mesh generation algorithms with
guaranteed dihedral angles (notably
isosurface
stuffing).
During his time at Berkeley,
he also did lovely work in anisotropic mesh generation.
He now works at Google.
JESSICA SCHOEN
is studying robust anisotropic mesh generation in the plane and on surfaces.
For over 30 years, researchers and government agencies have put forth
nutritional edicts that are unsupported, and often contradicted, by their own
data:
“saturated fat
(or all fat) is bad for you”;
“polyunsaturated seed oils are good for you”;
“whole grains are healthy”;
“fiber is important
for good health”;
“carbohydrates are
essential”;
“high
LDL cholesterol (or total cholesterol) causes heart disease”;
“fat
is fattening”;
“obesity can be combatted by
eating less and
exercising more.”
The public and press are unaware how much
evidence nutritional authorities have had to ignore to perpetuate these
notions, which survive on account of ambition, politics, and fear of scientific
ostracism, rather than good science. Meanwhile, a tide of evidence has quietly
risen implicating carbohydrates as the primary cause of heart disease,
diabetes,
overweight,
and perhaps even Alzheimer's disease and many cancers.
Yet carbohydrate consumption has risen sharply in response to official
demonization of dietary fat, causing increases of type 2 diabetes and obesity.
The American Medical Association, the
American
Heart Association, the
American Diabetes
Association,
and many other authorities have blood on their hands, and
they will continue to lead us lambs into the slaughterhouse of carbohydrate
poisoning until the culture of nutritional research is reformed.
While I've been aware of these facts for some time, I now have a rigorous
account to direct people to. Gary Taubes, in
Good
Calories, Bad Calories—his new
exposé of what the scientific data really reveal—writes,
“The institutionalized vigilance, `this unending exchange of critical
judgment,' is nowhere to be found in the study of nutrition, chronic disease,
and obesity, and it hasn't been for decades. For this reason, it is difficult
to use the term `scientist' to describe those individuals who work in these
disciplines. … The result is an enormous enterprise dedicated in
theory to determining the relationship between diet, obesity, and disease,
while dedicated in practice to convincing everyone involved, and the lay
public, most of all, that the answers are already known and always have
been—an enterprise, in other words, that purports to be a science and yet
functions like a religion.” Harsh words, but words entirely justified by
the data in the research literature—though the papers that present those
data often go through great contortions to
explain them away and
defend the dogma.
I call upon the National Institutes of Health (NIH) to fund large randomized
controlled trials that test the hypothesis that carbohydrates are central
in the etiology of coronary heart disease, diabetes, and obesity. Over the
past two decades, the NIH has dedicated its largest nutritional grants to
unsuccessfully confirming the “fat is bad” hypothesis, while
neglecting all competing hypotheses. We are all suffering for this
misallocation of resources.
“[Wisdom] is earned through disgrace, through painful realization of
the inadequacy of your personal world view.”
—
Nat Hillard
“In my psychedelic, hazy-vision state, where I reach the ultimate
heightened awareness of the beer-buzz, I realise the true meaning of exams:
that professors are evil, torture-loving beings, and that we cannot blame them
for their shortcomings.”
—
Rob Chung
“We need a more lasting form of negative feedback than just
paper rejections.”
— Jonathan Hardwick
on research