A Conversation with Ulf Grenander

Ulf Grenander was born in Vastervik, Sweden, on July 23, 1923. He started his undergraduate education at Uppsala University, and earned his B.A. degree in 1946, the Fil. Lic. degree in 1948 and the Fil. Dr. degree in 1950, all from the University of Stockholm. His Ph.D. thesis advisor was Harald Cram\'{e}r. Professor Grenander is well known for pathbreaking research in a number of areas including pattern theory, computer vision, inference in stochastic processes, probabilities on algebraic structures and actuarial mathematics. He has published more than one dozen influential books, of which Statistical Analysis of Stationary Time Series (1957, coauthored with M. Rosenblatt), Probabilities on Algebraic Structures (1963; also in Russian) and Abstract Inference (1981b) are regarded as classics. His three-volume lecture notes, namely, Pattern Synthesis (vol. I, 1976), Pattern Analysis (vol. II, 1978) and Regular Structures (vol. III, 1981a; also in Russian) created and nurtured a brand new area of research. During 1951--1966, Professor Grenander's career path took him to the University of Chicago (1951--1952), the University of California--Berkeley (1952--1953), the University of Stockholm (1953--1957), Brown University (1957--1958) and the Institute for Insurance Mathematics and Mathematical Statistics (1958--1966) as its Professor and Director. From 1966 until his retirement he was L. Herbert Ballou University Professor at Brown University. Professor Grenander also held the position of Scientific Director (1971--1973) of the Swedish Institute of Applied Mathematics. He has earned many honors and awards, including Arhennius Fellow (1948), Fellow of the Institute of Mathematical Statistics (1953), Prize of the Nordic Actuaries (1961), Arnberger Prize of the Royal Swedish Academy of Science (1962), Member of the Royal Swedish Academy of Science (1965), Guggenheim Fellowship (1979) and Honorary Fellow of the Royal Statistical Society, London (1989). He has delivered numerous prestigious lectures, including the Rietz Lecture (1985), the Wald Lectures (1995) and the Mahalanobis Lecture (2004). Professor Grenander received an Honorary D.Sc. degree (1993) from the University of Chicago and is a Fellow of both the American Academy of Arts and Sciences (1995) and the National Academy of Sciences, U.S.A. (1998). Professor Grenander's career, life, passion and hobbies can all be summarized by one simple word: Mathematics.Comment: Published at http://dx.doi.org/10.1214/088342305000000313 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Time Series Analysis, Cointegration, and Applications

The two prize winners in Economics this year would describe themselves as "Econometricians," so I thought that I should start by explaining that term. One can begin with the ancient subject of Mathematics which is largely concerned with the discovery of relationships between deterministic variables using a rigorous argument. (A deterministic variable is one whose value is known with certainty.) However, by the middle of the last millennium it became clear that some objects were not deterministic, they had to be described with the use of probabilities, so that Mathematics grew a substantial sub-field known as "Statistics." This later became involved with the analysis of data and a number of methods have been developed for data having what may be called "standard properties."time series; cointegration

Art, public authorship and the possibility of re-democratization

The subject of this study is a large public art project by German artist Jochen Gerz, which was part of the urban regeneration program The Phoenix Initiative in Coventry City, 1999-2004. The study presents a short historical backdrop to Gerz’s work by way of defining ‘public authorship’ of which the Coventry project is one example. It extends the literature on contemporary countermonument by assessing Gerz’s artistic strategy in using a monument to exploring the conditions of public culture and possible shape of a cultural public sphere in the contemporary city. The public art project lasted over five years and was a mechanism by which the political issues at stake in the public life of Coventry, particularly the socio-historic conflicts that are constitutive of its civic identity, were articulated. The study argues that public authorship succeeded in identifying some crucial coordinates in the political constitution of public culture in Coventry, but in the face of competing civic rhetoric and new urban policy initiatives, the project remains an open inquiry. This study concludes by identifying some critical lines of inquiry for future studies in art’s critical role in the public sphere

Generating and Sampling Orbits for Lifted Probabilistic Inference

A key goal in the design of probabilistic inference algorithms is identifying and exploiting properties of the distribution that make inference tractable. Lifted inference algorithms identify symmetry as a property that enables efficient inference and seek to scale with the degree of symmetry of a probability model. A limitation of existing exact lifted inference techniques is that they do not apply to non-relational representations like factor graphs. In this work we provide the first example of an exact lifted inference algorithm for arbitrary discrete factor graphs. In addition we describe a lifted Markov-Chain Monte-Carlo algorithm that provably mixes rapidly in the degree of symmetry of the distribution