Benjamin H. Alexander formally took over yesterday as the second president of the University of the District of Columbia, pledging to make the school a "flagship institution" with doctoral programs and courses to prepare students for the technological age.

"There will be open admissions at UDC, but there will not be open graduations," Alexander said at the installation ceremony, which was held in the outdoor plaza at the UDC Van Ness campus. "Our faculty will not coddle students . . . ," he said. "Doing so only dooms people to the junk heap of no success."

Looking trim at 60 in a pale grey suit set off by a red tie, Alexander grinned widely as the platform guests, including Mayor Barry, City Council members, leaders of the D.C. public schools and the UDC board of trustees -- each dressed in cap and gown -- spoke of the new spirt of optimism which Alexander has promised to bring to the university.

"Already we see the new direction of the university taking shape and form," said D.C. Schools Superintendent Floretta D. McKenzie. "A new spirit is forming . . . a new level of expectation is surfacing in the community."

After the traditional investiture, in which Alexander donned the official black gown and gold hood of the presidency and received the gold mace and medallion that symbolize his office, the new president pledged that stiffer standards for academic performance would be "vigorously enforced."

Alexander drew loud applause when he noted that last August, the university began enforcing for the first time a five-year-old standard for minimum grade point averages. At that time, 1,000 students were suspended and another 800 expelled for failing to achieve the required average.

A touch of the personal also came through as Alexander told of a recent visit he had made with his 22-year-old daughter to the place in Georgia where his grandfather, Lewis Rumph, had been a plantation slave. As soon as his grandfather was freed, Alexander recalled, he changed the family name because "rump is something you sit on and he had heard of Alexander the Great."

"The descendants of my grandfather are now doctors, lawyers, judges, businessmen, politicians -- and a university president" while the descendents of his grandfather's former owner, he said, are still tilling the land in Georgia. "I say to you that being poor is no handicap," Alexander said forcefully.

The new president, who spoke extemporaneously despite a prepared text, announced to the crowd that the mayor had pledged his support for the construction of a new science building. As president, Alexander said he intended to see through the construction of a new downtown campus at Mount Vernon Square, a project long stalled by Congressional opposition.

Alexander replaces Lisle C. Carter Jr., first president of the university formed by the merger of D.C. Teachers College, Federal City College and the Washington Technical Institute. UDC officials have scheduled a ceremony today naming the plaza at the Van Ness campus after former WTI president Cleveland L. Dennard.

Despite the upbeat tone of yesterday's ceremony, relations between Alexander and some university trustees and faculty remain strained.

No representative of the Faculty Senate or Faculty Association was invited to speak at yesterday's installation or to sit among platform guests -- a decision which Faculty Senate President Wilmer L. Johnson called "a deliberate affront . . . based on biased opinion rather than academic protocol."

Marjorie Parker, chairman of the board of trustees, said the faculty leadership was excluded because they had "pursued litigation" to try to block Alexander's appointment. A suit filed by five trustees seeking to halt the appointment is still pending in D.C. Superior Court.

Alexander told a reporter yesterday that the board of trustees, not he, planned the installation program. He expressed his continued interest in working with all members of the faculty.

Johnson said that Alexander had angered many faculty members last week when he unexpectedly requested that the board of trustees delay ratification of the faculty's new contract after negotiations had concluded. Alexander objected to some provisions related to the number of hours faculty members are required to teach.