In the academic world, Miller has been an adjunct professor for more than 50 years, beginning at the University of Houston.   He was also a professor at the graduate schools of business at New York University and Fordham University, and started the Business and Management Department at Northeastern Illinois University in Chicago.   Miller has five degrees, including an honorary doctorate from Bethany College (W. Va.), where he has been a trustee for 46 years.   He also was executive-in residence at the graduate business schools at the University of Toronto, Wyoming and Illinois.