Oscar Mayer Oscar Mayer The Oscar Mayer Company is an American meat and cold cut production company, owned by the American food company Kraft Heinz. It is known for its hot dogs, bologna, bacon, ham and Lunchables products. German immigrant Oscar F. Mayer (1859–1955), born in Kösingen, Germany, began working at a meat market in Detroit, Michigan, and later in Chicago, Illinois. In 1883, Mayer and his brother Gottfried leased the Kolling Meat Market on the near-northside of Chicago. The Mayer brothers sold bratwurst, liverwurst, and weißwurst which was popular in the predominantly German neighborhoods around their Chicago meat market. As the
Slowly varying envelope approximation Slowly varying envelope approximation In physics, the slowly varying envelope approximation (SVEA, sometimes also called slowly varying amplitude approximation or SVAA) is the assumption that the envelope of a forward-travelling wave pulse varies slowly in time and space compared to a period or wavelength. This requires the spectrum of the signal to be narrow-banded—hence it also referred to as the narrow-band approximation. The slowly varying envelope approximation is often used because the resulting equations are in many cases easier to solve than the original equations, reducing the order of—all or some of—the highest-order partial derivatives. But the validity of the