How Emmy Noether's theorem uses the Lagrangian to provide a formula for calculating the quantity of symmetries in a system—like the orbit of planets.

Abstract: In the existing research on finite-time synchronization (FTS) control for fractional-order coupled neural networks (FOCNNs), signum function plays a crucial role in controller design. The ...

Just east of the battered town of Lyman, the Russia-Ukraine war now unfolds less with the sound of thunder than with the low electronic hum of First-Person View (FPV) drones. Above narrow forest ...

Some of the functions in this section, such as abs and signum, are apparently unrelated to trigonometric functions when considered as functions of real numbers only. The way in which they are extended ...