SRI International

About: SRI International is a nonprofit organization based out in Menlo Park, California, United States. It is known for research contribution in the topics: Ionosphere & Laser. The organization has 7222 authors who have published 13102 publications receiving 660724 citations. The organization is also known as: Stanford Research Institute & SRI.

Quantifier sloping in the sri core language engine

Abstract: An algorithm for generating the possible quantifier scopings for a sentence, in order of preference, is outlined. The scoping assigned to a quantifier is determined by its interactions with other quantifiers, modals, negation, and certain syntactic-constituent boundaries. When a potential scoping is logically equivalent to another, the less preferred one is discarded.The relative scoping preferences of the individual quantifiers are not embedded in the algorithm, but are specified by a set of rules. Many of the rules presented here have appeared in the linguistics literature and have been used in various natural language processing systems. However, the co-ordination of these rules and the resulting coverage represents a significant contribution. Because experimental data on human quantifier-scoping preferences are still fragmentary, we chose to design a system in which the set of preference rules could be easily modified and expanded.The algorithm described has been implemented in Prolog as part of a larger natural language processing system. Extensions of this algorithm are in progress.

Interactions of Blackbody Radiation with Atoms

Abstract: Blackbody radiation affects low-frequency (${h}_{\ensuremath{ u}}\ensuremath{\ll}\mathrm{kT}$) atomic transitions both by inducing transitions and producing ac frequency shifts, important effects that have previously been ignored. Here we report the calculation and experimental observation of a manifestation of the former, the threefold reduction of the Na $\mathrm{np}$ radiative lifetimes by 300-K blackbody-radiation-induced stimulated emission and absorption. Estimates of ac frequency shifts for Rydberg and ground-state atoms are given.