The Mayan town of Uxmal, in Yucatán, was founded c. A.D. 700 and had some 25,000 inhabitants. The layout of the buildings, which date from between 700 and 1000, reveals a knowledge of astronomy. The ...

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Abstract: This article provides a tutorial introduction to disk margins. These are robust stability measures that account for simuitaneous gain and phase perturbations in a feedback system. The ...

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