that they respond to the demands and realities of the social and organizational development; the engineer Jorge Johnson, professor whose vision and expertise played a key role in the conceptual direction and design of the workshops sequence; the engineer and entrepreneur Luis Carlos Gaviria, Monterrosa, A

requirements. Derivations of the formulas and a numerical example are also presented. * David M. Allen is an Associate Professor in the Department of Statistics, University of Kentucky. This manuscript 1fas prepared while the author was

This paper provides the complete list of papers that were read and discussed in graduate seminars run in 1998 and 2001 by Professor Donald Johnson of the University of Illinois. A literature sleuth, Professor Johnson’s courses provide insight into what he thought were themajor papers and books

Dedicated to Professor Yasuhiko Kitada on the occasion of his sixtieth birthday ABSTRACT. In this paper we construct new obstructions for the surjectivity of the Johnson homomorphism of the automorphism group of a free group. We also deter-mine the structure of the cokernel of the Johnson

as special modelling advisor Professor Tom Johnson of the University of Missouri-Columbia, USA, and

Thank you to the residents of the Heartside neighborhood who were so gracious in allowing me to speak with them about their experiences. You were my very best teachers and should receive full credit for the following paper. Thank you to my thesis committee- Professor Jerry Johnson, Professor

x i+1 . Idea Execute a 2-out-of-2 sharing scheme for each pair of parties in the scheme. In other words, pick x 1 x 2 = y 1 y 2 = z 1 z 2 = x, and give party 1 shares x 1 and z 2 , party 2 shares z 1 and y 2 , and party 3 y 1 and x 2 . These schemes have a threshold of 2: 2 users can recover x. The latter scheme obviously generalizes to w-out-of-n sharing schemes by using w-out-of-w sharing schemes, but the size of each share is proportional to . This suggests a notion of e#ciency for sharing schemes. Definition 1 The rate of a sharing scheme is the ratio of the size of the secret to the size of each share. For unconditionally secure schemes, rate 1 is optimal. To see why, suppose a set of users, B = {i 1 , . . . , i k }, is allowed to reconstruct the secret x and each user's share of the secret is of length # < |x|. Then users i 1 , . . . , i k-1 can guess user i k 's share and recover x. Rates greater than 1 can be achieved by allowing fuzzy thresholds,

, Professor Patrick Chapman, for giving me the opportunity to pursue graduate studies here at the University of Illinois at Urbana-Champaign. I would also like to thank Professor Peter Sauer for helping me complete this research. This work was supported by The Graduate College Fellowship and SURGE Fellowship

criterion of economists that nobody be worse off after the reform than they were before it. We illustrate how one can use a quantitative model of the Danish economy to determine what reforms could be Pareto improvements if one allowed compensation of losers. Dewey H. Johnson Professor of Economics

iii ACKNOWLEDGMENTS I would like to thank my thesis committee-- Professor Andrew Johnson,