This paper presents lessons learned during the development of NASA's Systems Test and Operations Language (STOL) Intelligent Tutoring System (ITS), being developed at NASA Goddard Space Flight Center with support by Carlow Associates Incorporated and Computer Sciences Corporation. The purpose of the intelligent tutor is to train STOL users by adapting tutoring based on inferred student strength...

Tryptophan has been widely used as a probe of protein environment and dynamics. Proper interpretation of the experimental results requires a detailed understanding of tryptophyl photoprocesses, so much effort has been made to understand the fluorescence decay of zwitterionic tryptophan. For a review of these efforts, see ref. [l] . It is now well established that the fluorescence decay of trypt...

In this paper, we extend the construction of a fuzzy subgroup generated by a fuzzy subset to $L$-setting. This construction is illustrated by an example. We also prove that for an $L$-subset of a group, the subgroup generated by its level subset is the level subset of the subgroup generated by that $L$-subset provided the given $L$-subset possesses sup-property.