Visual determination of hue suprathreshold tolerances

A visual experiment was performed to generate suprathreshold tolerances sampling the direction of CIELAB hue, thereby extending the RIT-Dupont dataset. Thirty nine color centers including three complete hue circles at different lightness or chroma levels and three CIE recommended colors (red, green, blue) were evaluated for hue discrimination. Forty five observers participated in the pass/fail experiments. A total of 32,226 visual observations were made. The statistical method, logit analysis with 3-dimensional normit function, was used to determine the hue discrimination suprathreshold for each color center. The results indicated that the hue discrimination suprathresholds of observers varied with hue angle. The suprathreshold also increased with the chroma position of a given color center. The results were compared with current color-difference formulae, CMC, BFD and CIE94. A mathematical equation was derived from the present dataset

Five-dimensional generalized f(R)f(R) gravity with curvature-matter coupling

The generalized $f(R)$ gravity with curvature-matter coupling in five-dimensional (5D) spacetime can be established by assuming a hypersurface-orthogonal spacelike Killing vector field of 5D spacetime, and it can be reduced to the 4D formulism of FRW universe. This theory is quite general and can give the corresponding results to the Einstein gravity, $f(R)$ gravity with both no-coupling and non-minimal coupling in 5D spacetime as special cases, that is, we would give the some new results besides previous ones given by Ref.\cite{60}. Furthermore, in order to get some insight into the effects of this theory on the 4D spacetime, by considering a specific type of models with $f_{1}(R)=f_{2}(R)=\alpha R^{m}$ and $B(L_{m})=L_{m}=-\rho$, we not only discuss the constraints on the model parameters $m$, $n$, but also illustrate the evolutionary trajectories of the scale factor $a(t)$, the deceleration parameter $q(t)$ and the scalar field $\epsilon(t)$, $\phi(t)$ in the reduced 4D spacetime. The research results show that this type of $f(R)$ gravity models given by us could explain the current accelerated expansion of our universe without introducing dark energy.Comment: arXiv admin note: text overlap with arXiv:0912.4581, arXiv:gr-qc/0411066 by other author

Isolation performance metrics for personal sound zone reproduction systems

Two isolation performance metrics, Inter-Zone Isolation (IZI) and Inter-Program Isolation (IPI), are introduced for evaluating Personal Sound Zone (PSZ) systems. Compared to the commonly-used Acoustic Contrast metric, IZI and IPI are generalized for multichannel audio, and quantify the isolation of sound zones and of audio programs, respectively. The two metrics are shown to be generally non-interchangeable and suitable for different scenarios, such as generating dark zones (IZI) or minimizing audio-on-audio interference (IPI). Furthermore, two examples with free-field simulations are presented and demonstrate the applications of IZI and IPI in evaluating PSZ performance in different rendering modes and PSZ robustness

DRIVE SYSTEMS INCLUDING SLIDING MODE OBSERVERS AND METHODS OF CONTROLLING THE SAME

At least one example embodiment discloses a drive system including a motor including a rotor, the motor configured to receive a measured current, a controller configured to generate a Voltage command for the motor, a sliding mode observer configured to determine an estimated current for the motor based on the Voltage command, determine a difference between the measured current and the estimated current, and determine a Switching control vector and an estimator con figured to estimate a rotor position based on the Switching control vector, the Switching control vector being determined based on the difference and adaptive parameters of the sliding mode observer, the controller being further configured to control the motor based at least in part on the estimated rotor position