The ability of compensators (e.g., bow-tie filters) designed for kV cone-beam computed tomography (CT) to reduce both scatter reaching the detector and dose to the patient is investigated. Scattered x rays reaching the detector are widely recognized as one of the most significant challenges to cone-beam CT imaging performance. With cone-beam CT gaining popularity as a method of guiding treatmen...

We investigate basic properties of the set of observer-based state-space compensators (OBCs). In particular, we are interested in how much of this set is occupied by its OBC members. We examine both classical OBCs and generalized OBCs, as developed in [D. Cobb, SIAM J. Control Optim., 50 (2012), pp. 1921–1949]. We perform our analysis for both real and complex compensators. In every case, we sh...

Both the Doob-Meyer and the Graversen-Rao decomposition theorems can be proved following an approach based on predictable compensators of discretizations and weak-L technique, which was developed by K.M. Rao. It is shown that any decomposition obtained by Rao’s method gives predictability of compensators without additional assumptions (like submartingality in the original Doob-Meyer theorem or ...

Introduction: Multilevel converters are finding considerable attention in academia and industry as one of the preferred choices for high power conversion applications, such as traction drives, active filters, reactive power compensators, photovoltaic power conversion, uninterruptible power supplies, static compensators and flexible AC transmission systems. In general, multilevel converters are ...

It has been a practice in control system design to provide certain means of control in any control system by using different techniques such as adding compensators like PI, PD, and PID, with the incorporation of machine intelligence techniques such as fuzzy logic, artificial neural networks, and evolutionary computation. This paper presents a design approach in the development of compensators f...

Traditionally, an anti-windup compensator is activated when control signal saturation occurs. An alternative approach is to activate the compensator at a level below that of the physical control constraints: the antiwindup compensator is activated in anticipation of actuator saturation. Recent studies have proposed systematic methods for the construction of such anticipatory anti-windup compens...

In certain applications the use of stable compensators greatly simplifies controller testing and implementation. Unfortunately, standard LQG theory, as well as mixednorm H2/H, theory, may yield compensators that are unstable. The problem of synthesizing stable stabilizing controllers has been of interest for many years [14], and a variety of techniques have been proposed based on modifications ...

The discrete-time optimal projection equations, which constitute necessary conditions for optimal reducedorder LQG compensation, are strengthened. For the class of minimal stabilizing compensators the strengthened discrete-time optimal projection equations are proved to be equivalent tofirst-order necessary optimality conditionsfor optimal reduced-order LQG compensation. The conventional discre...