Stability of systems with nonlinear feedback through randomly time-varying delays

In a large class of multiloop control systems, many feedback loops are "closed" through a time-shared digital computer, using algorithms which require information from sources which are sampled at a rate which is not synchronized with the sampling of the individual "plants." This missynchronization, in conjunction with variations in the computer's task load caused by "interrupts," results in a randomly time-varying delay in the closing of the various feedback loops. Consequently, the dynamics of each controlled "plant" in such a system may be modeled by means of a stochastic delay-differential equation. This paper presents some new research results concerning the sample stability (as opposed to statistical, or ensemble stability) of nonlinear stochastic delay-differential equations.     

The emplacement mechanisms and growth styles of the GuposhanHuashan batholith in western Nanling Range, South China

The Guposhan-Huashan batholith was emplaced during transition from Tethysian tectonic regime to Pacific tectonic regime in the Middle-Late Jurassic. The regional EW-striking Yishan-Quannan basement deep fault zone, associated with the Tethysian regime, is thought likely to control the formation of the batholith. The development of the batholith was, however, achieved when the Pacific tectonic extensional regime dominated. The batholith consists of seven individual intrusive units that were emplaced subseque...     

On the almost-sure sample stability of systems with randomly time-varying delays

In a large class of multi-loop control systems, many feedback loops are “closed” through a time-shared digital computer, by means of algorithms which require information from sources which are sampled at a rate which is not synchronized with the sampling of the individual “plants”. This mis-synchronization, coupled with variations in the computer's task load caused by “interrupts”, results in a randomly time-varying delay in the closing of the various feedback loops. Consequently, the dynamics of each controlled “plant” in such a system may be modeled by means of a stochastic delay-differential equation. This paper presents some new research results concerning the sample stability, as opposed to statistical, or ensemble stability, of linear stochastic delay-differential equations.     

Intelligent user interface for expert systems applied to powerplant maintenance and troubleshooting

A research and development project is under way to specify, design, construct, and evaluate a user interface system to meet the requirements of a knowledge-based system for gas turbine electronics equipment maintenance and troubleshooting. The user interface is a portable device with text display, video and overlay graphics display, voice recognition and speech production, special-function keypad, and printer. A modular software structure based on a serial communications protocol between the user interface device and expert system host computer provides flexibility, expandability, and a simple, effective user-interface dialog