This paper concerns the structure that can be achieved by feedback in descriptor systems that lack controllability at innnity. Staircase and double staircase condensed forms obtained through a sequence of orthogonal state transformations display when and how feedback can be used to achieve minimal index. Furthermore, they reveal that the modes that are uncontrollable at innnity have a xed minim...

Controlling Chaos could be a big factor in getting great stable amounts of energy out of small amounts of not necessarily stable resources. By definition, Chaos is getting huge changes in the system’s output due to unpredictable small changes in initial conditions, and that means we could take advantage of this fact and select the proper control system to manipulate system's initial conditions ...

Complete attitude control of a spacecraft is not possible with only one single-gimbal variable-speed control moment gyro due to the conservation of angular momentum. However, partial attitude control without violating the angular momentum conservation principle is still possible. In this paper feedback controllers using only one singlegimbal variable-speed controlmoment gyro are presented that ...

We consider the problem of active reduction of the structural vibrations induced by the sloshing of large masses of fuel inside a partly full tank. The proposed study focuses on an experimental device mimicking an aircraft wing made of an aluminum rectangular plate equipped with piezoelectric patches at the clamped end and with a cylindrical tip-tank, more or less filled with liquid. After deri...

[1] Ross ice streams supply over 90% of the ice volume flowing out of the Ross sector of the West Antarctic ice sheet (WAIS). Stoppage of Ice Stream C (ISC) ca. 150 years ago appears to have pushed this sector of WAIS from negative into positive mass balance [Joughin and Tulaczyk, 2002]. We propose an explanation for the unsteady behavior of ISC using a new numerical ice-stream model, which inc...

Seeking the optimal control of spacecraft orbital maneuvers with non-smooth control logic in feedback sense, we extend our recently developed technique based on the Hamilton-Jacobi theory. Specifically we propose a new methodology stemming from the direct use of generating functions for solving optimal feedback control problem. Starting from the Hamilton-Jacobi equation for generating functions...

Achievements of the Space Shuttle experience and recent research activities were analyzed and absorbed, and a rapid generation technique of trajectories was focused on for the terminal area of reentry runway-landing flight vehicles. Based on the present processing capability of onboard computers, the trajectory geometry preset planning can be replaced by logic condition based algorithms which c...

An earlier analysis of pore-water salinity (chlorinity) in two deep-sea cores, using terminal constraint methods of control theory, concluded that although a salinity amplification in the abyss was possible during the LGM, it was not required by the data. Here the same methodology is applied to δOw in the upper 100 m of four deep-sea cores. An ice volume amplification to the isotopic ratio is, ...

We propose a mathematical model for cholera with treatment through quarantine. The model is shown to be both epidemiologically and mathematically well posed. In particular, we prove that all solutions of the model are positive and bounded; and that every solution with initial conditions in a certain meaningful set remains in that set for all time. The existence of unique disease-free and endemi...

We consider the problem of stabilizing sets parametrized by a single variable. Our approach is based on the solution to the maneuvering problem. In this problem, the state of the system is driven to a path that coincides with the set, and the particular location on the path is determined dynamically from the value of the state. Within this control structure, we induce a separation of time scale...