0-1串成的世界

（转自2006年国际数学家大会官方网站）

Plenary Lecture: Ronald DeVore

The World of Zeros and Ones
When we download the photographs taken with our digital camera at the last party onto the computer, we usually only see how flattering or unflattering the camera has been to us. But there are others, such as in some well-known science fiction films, who see a series of zeros, ones and a mass of calculations that determine the quality of the images. This is the case of Ronald DeVore, who will give one of the plenary lectures at the International Congress of Mathematicians in Madrid. This North American mathematician says that “for a mathematician, an image is a function, and the values of its pixels are the values of the function”.

Professor DeVore is attempting to find a better numerical solution to problems arising in the field of computation. In his lecture he will provide different examples of “optimal computation”. One of these examples concerns images stored in a computer or sent via Internet. The total number of bits that can be used is generally determined by the device, the CD or DVD, or by the communication channel. If the number of bits is fixed, then the problem resides in providing the most faithful representation of the image, given the number of bits. However, it is not a question of compressing a single image, but rather of repeating this process millions of times every day. In order to do this, different types of images are studied and a method of compression is sought that gives the best results for an entire type.

The optimization of solutions is not solely confined to the question of pixels. A further example provided by professor DeVore is taken from the sphere of communications. Thousands of signals – from a cell phone or a radio, for example – are emitted every second. How can the most relevant signals be identified in the shortest possible time? For instance, when it concerns an emergency call for help? In this case, DeVore compares his work to a game; he says it would be like determining the fewest number of questions one could ask in order to guess any number between 1 and 128 that someone has chosen at random.

Although the ability to see life in terms of zeros and ones is not a gift available to all, if we had a miraculous pair of spectacles that enabled us to do so, we would see this pair of numbers fluttering about all over the place.

Ronald DeVore was born in Detroit in 1941. He graduated in Mathematics in 1964 from the University of Eastern Michigan and gained his doctorate at the State University of Ohio in 1967. He worked at the University of Oakland for eight years, and in 1977 went on to become professor at the University of South Carolina, where in 1999 he founded the Industrial Mathematics Institute (IMI), of which he was director until his retirement in 2005. After retiring, he was made professor emeritus of the University of South Carolina. He has received many prizes in recognition of his work, such as the Humboldt award for research in 2002. In 2001 he was elected a member of the American Academy of Arts and Sciences.

Lecturer: Ronald DeVore

Title: Optimal Computation

Date: Tuesday, August 29th, 11:45-12:45

ICM2006 Scientific Programme: http://www.icm2006.org/scientificprogram/plenarylectures/