Ştefan S. Ralescu (born March 27, 1952 in Bucharest, Romania) is a leading statistician who has made significant contributions to the theory of statistical inference, mainly through asymptotic theory. He is a professor of mathematics and statistics at Queens College of the City University of New York in New York City. He studied first at the University of Bucharest obtaining an MA in mathematics (1976). He came to Indiana University in 1977, completing his PhD in 1981 under the direction of Madan Lal Puri. Before moving to New York, Ralescu was an Assistant Professor in the Division of Applied Mathematics at Brown University (1981–1984).
His research themes are varied, with noteworthy contributions in the fields of asymptotic theory of perturbed empirical and quantile processes, nonparametric density estimation and Stein estimation (see James–Stein estimator). Other applied work that received praise was written up in collaboration with Dr. A. Cassvan in connection to techniques using brain auditory evoked potentials (BAEP). The paper "Brainstem auditory evoked potential studies in patients with tinnitus and/or vertigo" is a standard reference.
He has published more than 70 research articles in prestigious scientific international periodicals. He is an Associate Editor of Journal of Statistical Planning and Inference (JSPI) and International Journal of Statistics and Systems (IJSS). He was a former director of the mathematics section of the PSC-CUNY Research Foundation.
Ralescu is an Elected Fellow of the International Statistical Institute. He is listed in Marquis Who's Who in Science and Engineering (since 1995).
His hobbies include rare book collecting and bridge. A bridge champion in his native Romania in the early 1970s, Ştefan Ralescu has published many bridge articles that have appeared in The Bridge World, the ACBL Bulletin and Bridge Today, among other magazines.
- D. Ralescu, S. Ralescu, A Class of Nonlinear Admissible Estimators in the One-Parameter Exponential Family, The Annals of Statistics, Vol. 9, No. 1, (1981), pp. 177–183.
- M. Seoh, S. Ralescu, M. L. Puri, Cramer Type Large Deviations for Generalized Rank Statistics, The Annals of Probability, Vol. 13, No. 1, (1985), pp. 115–125.
- M. L. Puri, S. Ralescu, Central limit theorem for perturbed empirical distribution functions evaluated at a random point, J. Multivar. Anal., Vol. 19, No. 2, (1986), pp. 273–279.
- A. Cassvan, S. Ralescu, E. Shapiro, F.G. Moshkovski, J. Weiss, Median and radial sensory latencies to digit I as compared with other screening tests in carpal tunnel syndrome, Am. J. Phy. Med., Vol. 67, (1988), pp. 221–224.
- P. Deheuvels, M.L. Puri, S.S. Ralescu, Asymptotic expansions for sums of nonidentically distributed Bernoulli random variables, J. Multivar. Anal., Vol. 28, No. 2, (1989), pp. 282–303.
- A. Cassvan, S. Ralescu, F.G.Moshkovski, E. Shapiro, Brainstem auditory evoked potential studies in patients with tinnitus and/or vertigo, Arch. Phys. Med. Rehabil., 71(8),(1990), pp. 583–586.
- S.S. Ralescu, Asymptotic deviations between perturbed empirical and quantile processes, J. Stat. Plan. Inference, Vol. 32, No. 2, (1992), pp. 243–258.
- S. Ralescu, A.C. Brandwein, W.E. Strawderman, Stein estimation for non-normal spherically symmetric location families in three dimensions, J. Multivar. Anal., Vol. 42, No. 1, (1992), pp. 35–50.
- S. Ralescu, A.C. Brandwein, W. E. Strawderman, Shrinkage Estimators of the Location Parameter for Certain Spherically Symmetric Distributions, Annals of the Institute of Statistical Mathematics, 45, (3), (1993), pp. 551–65.
- S. Ralescu, The law of the iterated logarithm for the multivariate nearest neighbor density estimators, J. Multivar. Anal., Vol. 53, No. 1,(1995), pp. 159–179.
- S.S. Ralescu, A Bahadur–Kiefer law for the Nadaraya empiric-quantile processes, Theory Probab. Appl. Vol. 41, No. 2, (1996), 296–306 and Teor. Veroyatn. Primen. Vol. 41, No. 2, (1996), pp. 380–392.
- S.S. Ralescu, M.L. Puri, Weak convergence of sequences of first passage processes and applications, Stochastic Processes and their Applications, Vol. 62, No. 2, (1996), pp. 327–345.
- S. Ralescu, On solutions for global Stein optimization problems with applications, J. Stat. Plann. Inference 103, No.1–2, (2002), pp. 391–400.