Background: The I-Space is a radiological imaging system in which Computed Tomography (CT)-scans can be evaluated as a three dimensional hologram. The aim of this study is to analyze the value of virtual reality (I-Space) in diagnosing acute occult scaphoid fractures.   Methods: A convenient cohort of 24 patients with a CT-scan from prior studies, without a scaphoid fracture on radiograph, ye...

This paper deals with the problem of observers design for implicit state affine systems for which the observer synthesis depends on the input excitation. Two approaches can be used to solve this problem; The first one consists in designing an observer which requires solving at each time an algebraic equation combined with an ODE system (implicit observer). The second approach proposed in this p...

SUMMARY This paper proposes a robust state observer for multi-input multi-output LTI systems. Unknown inputs of polynomial form and high-frequency measurement noises are considered in the system model. The unknown inputs and the noises are not in the same form. Multiple integra-tions of both the observer error signal and the measurement output are used for the observer design. The existence con...

ing the Observer To solve this problem with numerical constraints, Lurette computes an abstract version of the original observer. In this abstract observer, all numerical constraints have been replaced by new Boolean Variables. These new variables are treated as further inputs of the observer. Consider the following observer with a number of numerical constraints: node RELEVANT(X,Y,Z : int; A,B...

In this paper we investigate the impact of colorimetric observer categories on the prediction of the average suprathreshold color difference perception. The observer categories were obtained from an observer classification experiment, while the color difference data were obtained from an experiment involving a liquid crystal display (LCD) with fluorescent backlight. The same observer panel with...

This paper compares CIE 2006 model predictions and the 1964 10° standard colorimetric observer with the average observer data from three distinct subgroups of 47 Stiles-Burch observers formed on the basis of observer ages. For two of these subgroups, the long-wave sensitive (x-) color matching functions obtained from the CIE 2006 model did not accurately predict the intra-group average observer...

A hybrid static gain observer for systems described by a linear time-delay continuous part under impulsive feedback is suggested. The purpose of the observer is to asymptotically drive the state estimation error in the continuous states to zero and synchronize the sequence of modulated jump instants estimated by the observer with that of the plant. Conditions on the observer gain matrix to loca...

Globally convergent observers are designed for a class of systems with monotonic nonlinearities. The approach is to represent the observer error system as the feedback interconnection of a linear system and a time-varying multivariable sector nonlinearity. Using LMI software, observer gain matrices are computed to satisfy the circle criterion and, hence, to drive the observer error to zero. In ...

This paper deals with the design of a nonlinear observer for the inverted pendulum. The observer uses the standard structure of the linear observer with the linear model replaced by a nonlinear model. Nominal observer gains are determined from a linearized model. This model is also used to find a compromise between robustness and performance. The stability of the observer is then discussed and ...

This paper investigates the nonlinear observer design for mechanical systems, viz. nonlinear pendulum systems, undamped oscillators and Lienard systems. Explicitly, Sundarapandian’s Theorem (2002) for observer design for nonlinear systems is used to solve the problem of local exponential observer design for nonlinear pendulum systems, undamped oscillators and Lienard systems. Numerical examples...