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Research and Advances

Natural language with discrete speech as a mode for human-to-machine

A voice interactive natural language system, which allows users to solve problems with spoken English commands, has been constructed. The system utilizes a commercially available discrete speech recognizer which requires that each word be followed by approximately a 300 millisecond pause. In a test of the system, subjects were able to learn its use after about two hours of training. The system correctly processed about 77 percent of the over 6000 input sentences spoken in problem-solving sessions. Subjects spoke at the rate of about three sentences per minute and were able to effectively use the system to complete the given tasks. Subjects found the system relatively easy to learn and use, and gave a generally positive report of their experience.
Research and Advances

A randomized protocol for signing contracts

Randomized protocols for signing contracts, certified mail, and flipping a coin are presented. The protocols use a 1-out-of-2 oblivious transfer subprotocol which is axiomatically defined.The 1-out-of-2 oblivious transfer allows one party to transfer exactly one secret, out of two recognizable secrets, to his counterpart. The first (second) secret is received with probability one half, while the sender is ignorant of which secret has been received.An implementation of the 1-out-of-2 oblivious transfer, using any public key cryptosystem, is presented.
Research and Advances

A polynomial time generator for minimal perfect hash functions

A perfect hash function PHF is an injection F from a set W of M objects into the set consisting of the first N nonnegative integers where N ⩾ M. If N = M, then F is a minimal perfect hash function, MPHF. PHFs are useful for the compact storage and fast retrieval of frequently used objects such as reserved words in a programming language or commonly employed words in a natural language.The mincycle algorithm for finding PHFs executes with an expected time complexity that is polynomial in M and has been used successfully on sets of cardinality up to 512. Given three pseudorandom functions h0, h1, and h2, the mincycle algorithm searches for a function g such that F(w) = (h0(w) + g ° h1(w) + g ° h2(w)) mod N is a PHF.
Research and Advances

Computing in the home: shifts in the time allocation patterns of households

An empirical study of 282 users of home computers was conducted to explore the relationship between computer use and shifts in time allocation patterns in the household. Major changes in time allocated to various activities were detected. Prior experience with computers (i.e., prior to purchase of the home computer) was found to have a significant impact on the time allocation patterns in the household. The study provides evidence that significant behavior changes can occur when people adopt personal computers in their homes.

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