Dr. Dobb's Journal September, 2004
A million dollar prize went unclaimed in last year's DARPA Grand Challenge (http://www.darpa.mil/grandchallenge/), as none of the autonomous robot racers managed to travel more than eight miles of the 142 mile off-road course. DARPA, however, has decided to make a yearly event of the race. The next Grand Challenge has been scheduled for October 8, 2005, and the prize money has been doubled. This year, DARPA is also holding a Participants Conference "intended for participants, interested sponsors, and groups looking for others to help complete their teams." The conference will take place on August 14 in Anaheim, California.
Fifteen teams from a field of 106 applicants managed to qualify for the race in 2004. The best showing was made by "Sandstorm," a robotic Humvee built by a team at Carnegie-Mellon, which managed to complete 7.4 miles with an average speed of 15 mph (http://www.redteamracing.org/index.html). The Carnegie-Mellon team is already preparing for next year's race, and DARPA expects overall participation to rise significantly this year.
The Great Internet Mersenne Prime Search (GIMPS), a distributed computing effort that uses the spare computing cycles of volunteers to search for as-yet-unknown prime numbers, has discovered a 7,235,733-digit prime number. The new number, which can be concisely expressed as 2 to the 24,036,583th power minus 1, is the largest known prime and only the 41st known Mersenne prime. The discovery was made by Josh Findley, a consultant to the National Oceanic and Atmospheric Administration in La Jolla, California. He has been part of the GIMPS project (http://www.mersenne.org/) for five years; the specific calculation that led to the new discovery took two weeks to perform on his 2.4-GHz Pentium 4 PC.
Mersenne primes are named for Marin Mersenne, a French monk who published a sequence of these numbers in 1644, although he was not the first to study the relationship between prime numbers and numbers of the form 2n-1. For example, these numbers are prime when n equals 2, 3, 5, 7, 13, 17, 19, 31, 61, 89, 107, and 127.
This is the seventh Mersenne prime discovered by the GIMPS project over the last eight years. The Electronic Frontier Foundation offers a $100,000 prize for the discovery of the first 10-million-digit prime: "An award-winning prime could be mere weeks or as much as few years away—that's the fun of math discoveries," said GIMPS founder George Woltman in a prepared statement.
A team of researchers from the University of Southern California says their Variational Shape Approximation scheme lets 3D images be compressed with much more efficiency than existing methods (http://www-grail.usc.edu/pubs.html). Assistant professor Mathieu Desbrun worked with two postdoctoral researchers—Pierre Alliez, now with France's National Institute for Research in Information and Automation, and David Cohen-Steiner, now of Duke University—to produce the "Variational Shape Approximation" scheme, which represents 3D images as simplified meshes. It uses a technique called "Lloyd Clustering," from the field of machine learning, to dissect 3D objects into nonoverlapping connected HASH(0x80d2a8) that can then be separately optimized.
Microsoft is eliminating many of the restrictions on the use of its "shared source" license for Windows CE 5.0. The revised shared source license increases the source code that Microsoft is making available to more than 2.5 million lines of code, including the GUI, operating-system kernel, and the like. Among other revisions, the license for CE 5.0 lets developers customize the OS code in their software without having to sublicense the modified code back to Microsoft. For more information, see http://msdn.microsoft.com/embedded/.
Sun has announced the open-source availability of the Java 3D API and Project Looking Glass. The Java 3D API provides a set of object-oriented interfaces that support a high-level programming model you can use to build, render, and control 3D objects and visual environments. With the Java 3D API (http://www.java.sun.com/products/java-media/3D/), you can incorporate high-quality, platform-independent 3D graphics into Java-based applications and applets. Project Looking Glass (http://www.sun.com/software/project-looking-glass/) is an interface that offers an intuitive, 3D environment to interact with desktop apps.