in this paper, we investigate various kinds of extensions of twin-good rings. moreover, we prove that every element of an abelian neat ring r is twin-good if and only if r has no factor ring isomorphic to z2  or z3. the main result of [24] states some conditions that any right self-injective ring r is twin-good. we extend this result to any regular baer ring r by proving that every element of a...

The adaptive sliding-mode observer has been widely used to estimate the rotor flux and rotor speed in inverter-fed sensorless induction motor drives. However, the technique requires setting a priori the sliding-mode observer constants and also knowledge of the induction motor parameters. This particular aspect can cause significant errors in the estimation of the rotor speed used in sensorless ...

of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science OBSERVER-SIDE PARAMETER ESTIMATION FOR ADAPTIVE CONTROL By Jason Nezvadovitz August 2017 Chair: Warren Dixon Major: Mechanical Engineering In adaptive control, a controller is precisely designed for a certain model of the system, but that model’s...

abstract background and aim: cone beam computed tomography (cbct) produces high-quality data in periodontal diagnosis and treatment planning. the aim of this study was to compare the accuracy of cbct with intraoral digital and conventional radiography in the measurement of periodontal bone defects.  methods and materials: in this diagnostic research, two hundred and eighteen artificial osseous ...

A method is described by which it is possible to determine the high barrier to ring inversion and hindered rotation by neat racemization of optically active compounds when the racemization is caused by ring inversion or hindered rotation. The method is based preparation of sufficiently pure enantiomers, mainly by chromatography on swollen microcrystalline triacetylcellulose (TAC). By this t...

This paper investigates the problem of robust fault detection observer design for nonlinear Takagi–Sugeno models with unmeasurable premise variables subject to sensor faults and unknown bounded disturbance. The main idea is to synthesize a robust fault detection observer by means of a mixed H =H1 performance index. The considered observer is used to estimate jointly states and faults. Using the...

In this work the problem of designing a reduced-order observer to infer the concentration in a catalytic reactor with temperature measurements and a simplified model is addressed. The process motion has a poor observability property, meaning that a carefully tuned high-order EKF technique is required to design an observer. Here, a constructive low-high gain estimation scheme is considered to ac...

We propose a novel recursive design scheme of state observer for lower triangular nonlinear systems. The design begins from the bottom dynamics and propagates to upper dynamics recalling the backstepping scheme for nonlinear control. The proposed class of systems is fairly general since it includes non-uniformly observable or detectable multi-output systems. The error convergence to zero is pro...

In this paper, an observer-based decentralized fuzzy controller is designed for discrete-time interconnected fuzzy systems. Based on the fuzzy subsystem of the interconnected fuzzy system, the observer-based decentralized fuzzy controller is considered. By using the fuzzy subsystem and the observer-based decentralized fuzzy controller, the closed-loop system is obtained. From the closed-loop sy...

This paper is concerned with network-based sampled-data observer design problem for a class of switched linear systems in the finite-time H∞ sense. Outputs sampling and the detection of mode variations are both performed via a clock-driven approach, and networkinduced limitations involving transmission delays and data packet dropouts are also taken into account. Moreover, we introduce a novel m...