We aimed to investigate the characteristics of Parkinsonian features assessed by the unified Parkinson's disease rating scale (UPDRS) and determine their correlations with the computed tomography (CT) findings in patients with idiopathic normal pressure hydrocephalus (iNPH). The total score and the scores for arising from chair, gait, postural stability, and body hypokinesia in the motor examin...

This paper advocates disturbance observer based control (DOBC) for uncertain nonlinear systems. Within this framework, a nonlinear controller is designed based on the nominal model in the absence of disturbance and uncertainty where the main design specifications are to stabilize the system and achieve good tracking performance. Then a nonlinear disturbance observer is designed to not only esti...

Disturbance attenuation for a class of nonlinear systems under unknown disturbances is considered in this paper. Based on the Disturbance-Observer-Based Control (DOBC) concept, two design schemes are proposed for external disturbances generated by exogenous systems where the disturbances could be unbounded. One design scheme is obtained by augmenting the estimation of the disturbance into a sta...

The synchronization of the Hindmarsh-Rose neuron system with external disturbance is investigated via sliding mode control. Based on the Lyapunov stability theory, a single sliding mode controller is derived even when the response Hindmarsh-Rose neuron system with external disturbance. The numerical simulation is presented to verify the effectiveness of the proposed control scheme.

1 New Results on Output-Feedback Variable Structure Model-Reference Adaptive Control: Design and Stability Analysis Liu Hsu, Fernando Lizarralde and Aldayr D. de Araújo Abstract The Variable Structure Model-Reference Adaptive Control (VS-MRAC) redesign and stability analysis, presented earlier for the case of plants with relative degree n 2, is generalized to the case of arbitrary n 1. This pap...

Power systems are usually large non-linear systems, which are often subjected to low frequency electromechanical oscillations. Power System Stabilizers (PSSs) are often used as effective and economic means for damping the generators’ electromechanical oscillations and enhance the overall stability of power systems. Power system stabilizers have been applied for several decades in utilities and ...

For many nonlinear control systems, the chosen equilibrium determines both the steady-state efficiency and the dynamic performance. This paper addresses the issue of obtaining an optimal equilibrium in terms of some steady-state operation criteria for a Lur’e-type system and such an equilibrium can also guarantee a sufficiently large stability region in the dynamic domain such that the system c...

In disturbance-observer-based control, the closed loop system consists of a main feedback control loop and an inner disturbance observer loop. This paper presents a design method for a disturbance observer to satisfy closed loop performance specifications, provided that the main feedback controller is known. Taking advantage of certain fixedstructure disturbance observers, the disturbance obser...