17,175 research outputs found
MARKET CONDUCT IN THE U.S. READY-TO-EAT CEREAL INDUSTRY
The FTC's "shared monopoly" case was the focus of U.S. antitrust activity during the late 1970s, but prosecution of the cereal industry was terminated in 1981. We estimate the degree of market power in the industry, and find an increase in multilateral power after 1981.Marketing,
NASA systems autonomy demonstration project: Advanced automation demonstration of Space Station Freedom thermal control system
The NASA Systems Autonomy Demonstration Project (SADP) was initiated in response to Congressional interest in Space station automation technology demonstration. The SADP is a joint cooperative effort between Ames Research Center (ARC) and Johnson Space Center (JSC) to demonstrate advanced automation technology feasibility using the Space Station Freedom Thermal Control System (TCS) test bed. A model-based expert system and its operator interface were developed by knowledge engineers, AI researchers, and human factors researchers at ARC working with the domain experts and system integration engineers at JSC. Its target application is a prototype heat acquisition and transport subsystem of a space station TCS. The demonstration is scheduled to be conducted at JSC in August, 1989. The demonstration will consist of a detailed test of the ability of the Thermal Expert System to conduct real time normal operations (start-up, set point changes, shut-down) and to conduct fault detection, isolation, and recovery (FDIR) on the test article. The FDIR will be conducted by injecting ten component level failures that will manifest themselves as seven different system level faults. Here, the SADP goals, are described as well as the Thermal Control Expert System that has been developed for demonstration
A Unified Approach to High-Gain Adaptive Controllers
It has been known for some time that proportional output feedback will
stabilize MIMO, minimum-phase, linear time-invariant systems if the feedback
gain is sufficiently large. High-gain adaptive controllers achieve stability by
automatically driving up the feedback gain monotonically. More recently, it was
demonstrated that sample-and-hold implementations of the high-gain adaptive
controller also require adaptation of the sampling rate. In this paper, we use
recent advances in the mathematical field of dynamic equations on time scales
to unify and generalize the discrete and continuous versions of the high-gain
adaptive controller. We prove the stability of high-gain adaptive controllers
on a wide class of time scales
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