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Exploration of the nature of human communication and the media is a pre requisite to any assessment of the likely future role of communications . . We cannot assume that the nature of these things is transparently obvious to everyone and therefore commonly understood. Three developments in recent decades should adequately warn against such an assumption. First, we had the fiasco of social scientists trying to apply Shannon's mathematical theory of information as if it were a theory of human communication. 'In Shannon's use of information we cannot speak of how much information a person has only how much a message has. ' (Ackoff and Emery, 1972, p. 145). They would not have wandered into that blind alley if they had stopped to think about the nature of human communication. Second was the belated but wholehearted acceptance of the Heider theory of balance and its subse quent wane. Its wane had nothing to do with its inherent merits. It waned because it could not survive on the Procrustean bed of the psychologists' theory of choice. It did not occur to the psychologists to question their as sumptions about how people made the choices that lead to purposeful com munication (Ackoff and Emery, 1972, p. 58). The last example has been the bitter and unended furore about McLuhan. This time the psychologists and sociologists haye been strangely quiet but we can be sure this does not imply acquiescence in McLuhan's views."

Researchers and graduate students in the theory of stochastic processes will find in this 35th volume some thirty articles on martingale theory, martingales and finance, analytical inequalities and semigroups, stochastic differential equations, functionals of Brownian motion and of L vy processes. Ledoux's article contains a self-contained introduction to the use of semigroups in spectral gaps and logarithmic Sobolev inequalities; the contribution by Emery and Schachermayer includes an exposition for probabilists of Vershik's theory of backward discrete filtrations.

This volume contains 19 contributions to various subjects in the theory of (commutative and non-commutative) stochastic processes. It also provides a 145-page graduate course on branching and interacting particle systems, with applications to non-linear filtering, by P. del Moral and L. Miclo.

Besides topics traditionally found in the Seminaire de Probabilites (Martingale Theory, Stochastic Processes, questions of general interest in Probability Theory), this volume XXXIII presents nine contributions to the study of filtrations up to isomorphism. It also contains three graduate courses: Dynamics of stochastic algorithms, by M. Benaim; Simulated annealing algorithms and Markov chains with rare transitions, by O. Catoni; and Concentration of measure and logarithmic Sobolev inequalities, by M. Ledoux. These up to date courses present the state of the art in three matters of interest to students in theoretical or applied Probability Theory, and to researchers as well.

This is a reproduction of a book published before 1923. This book may have occasional imperfections such as missing or blurred pages, poor pictures, errant marks, etc. that were either part of the original artifact, or were introduced by the scanning process. We believe this work is culturally important, and despite the imperfections, have elected to bring it back into print as part of our continuing commitment to the preservation of printed works worldwide. We appreciate your understanding of the imperfections in the preservation process, and hope you enjoy this valuable book. ++++ The below data was compiled from various identification fields in the bibliographic record of this title. This data is provided as an additional tool in helping to ensure edition identification: ++++ How To Enjoy Pictures EMERY (M. S.) Prang Educational Co., 1898