On-board statistical detection and compensation of anomalous pilot-aircraft interactions

A statistical method for the on-board detection and compensation of adverse oscillations in pilot-aircraft systems is presented. A recursively updated linear model representing the pilot-aircraft system is used to continuously check for stability loss. The instability-related oscillations are detected early, using a statistical hypothesis test. Furthermore, a specially designed stability augmentation system assists the pilot during the instability periods. The method's effectiveness is demonstrated via data obtained from a flight simulator and a detailed simulation model.     

The characteristics of sharp (small-scale) boundaries of solar wind plasma and magnetic field structures

We investigate properties of large (>20%) and sharp (<10 min) solar wind ion flux changes using INTERBALL-1 and WIND plasma and magnetic field measurements from 1996 to 1999. These ion flux changes are the boundaries of small-scale and middle-scale solar wind structures. We describe the behavior of the solar wind velocity, temperature and interplanetary magnetic field (IMF) during these sudden flux changes. Many of the largest ion flux changes occur during periods when the solar wind velocity is nearly constant, so these are mainly plasma density changes. The IMF magnitude and direction changes at these events can be either large or small. For about 55% of the ion flux changes, the sum of the thermal and magnetic pressure are in balance across the boundary. In many of the other cases, the thermal pressure change is significantly more than the magnetic pressure change. We also attempted to classify the types of discontinuities observed.     

Weightlessness: a case history

The facts presented represent, for convenience, a composite clinical picture of the three crewmen aboard Skylab II as observed by me.     

A Nominator-Selector Two-Stage Signal Detection Scheme

A two-stage approach to computationally efficient signal detection is to nominate candidate signal vectors using a suboptimal, but computationally cheap, detection scheme, and subsequently perform optimal detection on the candidates. Bounds on the detection performance of this approach are presented along with sufficient conditions for optimality. Examples are presented of an optimal and nearly optimal two-stage detection scheme where computational costs are drastically reduced relative to the singli-stage optimal detector.