The main weakness of all control methodologies is the dependency of feedbacks to full state measurements. In practical situations, measuring the states of a given system may fail because sometimes the measurements are impossible and sometimes, possible, but too expensive. Observer design for highly nonlinear dynamics is an important issue, particularly when the locally observable dynamics are n...

Occupancy models that account for imperfect detection are often used to monitor anuran and songbird species occurrence. However, presence–absence data arising from auditory detections may be more prone to observation error (e.g., false-positive detections) than are sampling approaches utilizing physical captures or sightings of individuals. We conducted realistic, replicated field experiments u...

In this paper a novel method is proposed for construction of an exponential observer for nonlinear system. The presented method is based on direct solution of dynamic error without any linearzing of nonlinear terms. Necessary and sufficient conditions for construction of direct observer are presented. Stability of the observer is checked using Lyapunov theorem. Also the ability of this observer...

This article reviews the effects of the thermal environment on vigilance. A reinterpretation of early and contemporary studies contradicts the existing notion that vigilance is facilitated in ambient temperatures that exceed a comfortable level. Rather, performance is degraded as thermal homeostasis of the observer is disturbed. Significant breakdown in capability becomes manifest with measurab...

The problem of observer design for nonlinear systems has got great attention in the recent literature. The nonlinear observer has been a topic of interest in control theory. In this research, a modified robust sliding-mode observer (SMO) is designed to accurately estimate the state variables of nonlinear systems in the presence of disturbances and model uncertainties. The observer has a simple ...

The effect of ambient light on linearization of gray scales was studied in two experiments by measuring brightness-discrimination thresholds for stimuli as a function of ambient-light level. The luminance and contrast levels of stimuli were chosen to include typical instances encountered in electronically displayed medical images. Three ambient-light levels were used: 4 and 40 lx, which span th...

In this paper, we propose a new chaos-based communication scheme using the observers. The novelty lies in the masking procedure that is employed to hide the confidential information using the chaotic oscillator. We use a combination of the addition and inclusion methods to mask the information. The performance of two observers, the proportional observer (P-observer) and the proportional integra...

BACKGROUND To reduce the ambient concentration of waste anesthetic agents, exhaust gas scavenging systems are standard in almost all operating rooms. The incidence of contamination and the factors that may increase the concentrations of ambient anesthetic gases have not been evaluated fully during routine circumstances, however. METHODS Concentrations of nitrous oxide (N2O) in ambient air wer...

In this paper, a fault detection and accommodation scheme is designed, which is applicable to a large class of nonlinear systems. The nonlinear observer is designed to enable the detection of fault occurrences through comparison of observed states with their signatures. Under such circumstances, when a component fails, the fault accommodation control will be activated to compensate the effects ...