Joseph Armstrong Joseph Armstrong, a building service worker, died March 20 at Urbana. He was 51. Survivors include his wife, Sharon; a son; and a sister. Memorial contributions may be made to the Seymour United Methodist Church. George Dittmann George Dittmann, a retired instrument maker, died March 24 at Covenant Medical Center, Urbana. He was 72. Dittmann retired in 1987, after 30 years on the UI staff. He attended the UI and was an apprentice machinist at the Elgin Watch Co. Survivors include his wife, Marilyn; two sons; two daughters; two sisters; and four grandchildren. Hazel McInnes Hazel McInnes, a retired food service worker, died March 28 at the Urbana Americana Healthcare Center. She was 77. McInnes was employed at the Illini Union for 20 years. She retired in 1988. Survivors include a brother, a sister, two nieces and a nephew. Memorial contributions may be made to the American Heart Association. Earl Planty Earl Planty, a professor emeritus of management, died Dec. 19 at Boca Raton, Fla. He was 91. Planty was a faculty member in the College of Commerce and Business Administration from 1955 until he retired in 1967. He took a two-year leave of absence from the UI to serve as the dean of the College of Business Administration at Haile Selassie I University, Addis Ababa, Ethiopia, from 1964 to 1966. He was elected a fellow of the Academy of Management in 1960. Survivors include his wife, Marjorie; two daughters; four grandchildren; and two sisters. Memorial contributions may be made to the Research Division, National Alzheimer's Association, 919 N. Michigan Ave., Chicago, IL 60611. Lee A. Rubel Lee A. Rubel, a UI mathematician who advocated greater use of analog computers and was renowned in many branches of his field, died March 25 in Covenant Hospital, Urbana. He was 66. A memorial service will be held at 4 p.m. April 16 at Smith Memorial Hall. C. Ward Henson, a former chair of the mathematics department, said Rubel was "one of the most original and inspiring mathematicians of his generation. He kept his considerable creative powers to the very end of his life." Anil Nerode, a mathematician at Cornell University and vice president of the American Mathematical Society, said, "I regard [Rubel's work] as the most significant in differential algebra since ... the 1930s, and it deserves to be much more widely known." In his last years, Rubel developed mathematics to improve analog computers, which use equations rather than raw data, as do digital computers, to determine patterns. Analog computers can be used in conjunction with biological computing, neural networks, and particle accelerators, according to computer scientist Jonathan W. Mills at Indiana University in Bloomington. "Rubel's theoretical blueprint has been as important a contribution to analog computing as Alan Turing's machine was to digital computing," Mills said. Turing devised a theoretical computer that is a mathematical model of digital computers. "Rubel's work will be the foundation of analog computer research for the next decade and beyond." Rubel was editor of a variety of mathematical journals and served on committees of the American Mathematical Society. He became disenchanted with the AMS because, he wrote in the February issue of its journal, Notices, he felt the AMS had turned away from research and compromised "the pure pursuit of mathematics, whose aim is to discover, prove and understand theorems." A graduate of the Bronx High School of Science and of the City College of New York, Rubel earned a doctorate in mathematics at the University of Wisconsin in 1954. He was a visiting scholar at the Institute for Advanced Study in Princeton, N.J., from 1956 to 1958, and joined the UI faculty in 1958. He retired in 1993 to devote himself to research. Rubel is survived by his wife, Nina; a son; a daughter; and a brother. Memorial contributions may be made to the Arthur Danielyan Fund, P.O. Box 416, Champaign, IL 61824-0416, to provide partial support for a young Armenian mathematician. Richard Stegeman Richard Stegeman, retired professor of journalism, died March 27 at St. Peter's Manor, St. Louis. He was 59. Stegeman was on the UI faculty from 1984 to 1992. He was the editor of the Metro-East-Journal at East St. Louis in the 1970s and early '80s when the paper closed. He taught journalism at Cairo, Egypt, from 1965 to 1968. Survivors include his wife, Beatrice; a daughter; and a sister.