**
**Toby
Berger

Irwin and Joan Jacobs
Professor of Engineering, Electrical and Computer Engineering

392 Rhodes Hall

Phone: 607/255-1447

E-mail:
berger@ece.cornell.edu

B.S. 1962 (Yale); M.S. 1964, Ph.D. 1966 (Harvard)

Berger joined the
Cornell faculty in 1968. During graduate study he held a Raytheon Advanced
Study Fellowship, and subsequently was a senior scientist at Raytheon. At
Cornell he is associated with the Center for Applied Mathematics and the
graduate Field of Statistics. He was a Guggenheim fellow in 1976, a Japan
Society for Promotion of Science fellow in 1980, and a fellow of the Ministry
of Education of the People's Republic of China in 1981. In 1982 Berger
received the Frederick E. Terman Award (which recognizes an outstanding young
educator in electrical engineering) from the American Society for Engineering
Education. He has served as a consultant to Raytheon, IBM, Schlumberger,
Teknekron Communication Systems and AT&T Bell Labs. He is a fellow of the
Institute of Electrical and Electronics Engineers, a member of the Governing
Board and a past president of the IEEE Information Theory Group, and a past
editor-in-chief of the *IEEE Transactions on Information Theory. *He is a
fellow of the Institute of Electrical and Electronics Engineers and a member
of the American Association for the Advancement of Science, the American
Society for Engineering Education, Sigma Xi, and Tau Beta Pi. Berger directs
the DISCOVER Lab,
a research facility for video/audio compression development.

I conduct and supervise research in diverse disciplines including information theory, random fields, communication networks, video compression, signature verification, and coherent signal processing. I am particularly interested in situations in which information generated at several different locations must be transmitted over a network of communication links whose capacity is limited.

We have studied
throughput versus delay tradeoffs and robust design techniques in packet
communication systems. Other problems concern applying multiterminal
rate-distortion theory and multiterminal decision theory to situations in
which many remote, correlated sources are connected to a common processor via
separate communication links. This work is of significance for multisite
signal-processing applications such as interferometry, seismology, and emitter
location. We have contributed to the problem of optimum diversity coding,
known also as the* multiple descriptions problem*, in several cases
obtaining exact results for the ultimate capabilities of such systems.

The subject of random fields, which is under intense investigation in mathematics and physics, is being studied from the viewpoint of information theory. Analysis, synthesis, simulation, and encoding of random fields are all under investigation. A rigorous basis has been provided by extending the fundamental block and sliding-block coding theorems for sources and channels to situations characterized by multidimensional parameters. Work on rate-distortion theory for non-Gaussian random fields has included the establishment of a critical distortion phenomenon for the Ising model in two dimensions. We are exploring ties with statistical physics, including the information-theoretic implications of phase-transition phenomena. In particular, we have extended the Shannon McMillan theorem to stationary and ergodic fields on trees and have determined the cardinality of phase transition of symmetric fields on closed trees.

- Information Fields
and Communication Topologies
*(National Science Foundation)* - Lossy Data
Compression
*(National Science Foundation)* - Coordination of
Distributed Information and Decisions
*(National Science Foundation)* - Circuit-Switched Desktop Video and Data-Compressed Computer Graphics

- Berger, T. 1971.
*Rate-distortion theory: A mathematical basis for data compression.*Englewood Cliffs, NJ: Prentice-Hall. - Berger, T. 1972.
On the correlation coefficient of a bivariate, equal variance, complex
Gaussian sample.
*Annals of Mathematical Statistics*43:2000-03. - Berger, T. 1982.
Minimum entropy quantizers and permutation codes. [Invited paper, Special
Issue on Quantization] IEEE
*Transactions on Information Theory*IT-28:149-57. - Berger, T. and A.
H. Kaspi. 1982. Rate-distortion for correlated sources with partially
separated encoders.
*IEEE Transactions on Information Theory*IT-28:828-40. - Berger, T., and Z.
Zhang. 1983. Minimum breakdown degradation in binary source encoding.
*IEEE Transactions on Information Theory*29:807-14. - Berger, T., N.
Mehravari, D. Townsley, and J. K. Wolf. 1984. Random multiple-access
communication and group testing.
*IEEE Transactions on Communication*COM-32:769-79. - Hajek, B. E., and
T. Berger. 1987. A decomposition theorem for binary Markov random fields.
*The Annals of Probabiilty*15:1112-25. - Berger, T., and R.
W. Yeung. 1989. Multiterminal source encoding.
*IEEE Transactions on Information Theory*35(2):237-44. - Berger, T., and Z.
X. Ye. 1990. A bound on the phase transition region for ising models on
closed Cayley trees.
*Physica A*169:430-43. - Berger, T., and Z.
X. Ye. 1990. Entropic aspects of random fields on trees.
*IEEE Transactions on Information Theory*IT-36:1006-18. - Berger, T., A.
Hekstra, and A. Orlitsky. 1993. Asymptotic component densities in
programmable gate arrays realizing all circuits of a given size.
*Algorithmica*9:101-27. - Berger, T., and Z.
Chen. 1994. Reliability and availability analyses for Manhattan street
networks.
*IEEE Transactions on Communications*42:347-56. - Berger, T., and Z.
Zhang. 1995. Multiple desorption source coding with no excess marginal
rate.
*IEEE Transactions on Information Theory*in press.

**
Last Updated: January 23, 2001**