ABSTRACT
Robust method of short-term forecast of Covid-19 epidemic in small administrative units (districts) is proposed. By identifying similar sections of epidemic evolutions in the past it is possible to obtain short-term forecast of epidemic in given district. Examples of one and two-weeks forecasts for three cities in Poland during third epidemic wave (March and April 2021) are shown. Difference between epidemic evolutions in third wave and previous waves caused by Covid B.1.1.7 UK variant is observed. Proposed algorithm allows one to manage epidemic locally by entering or releasing anti-Covid restrictions in groups of small administrative units.
ABSTRACT
We review recent research on Zitterbewegung (ZB, trembling motion) of electrons in semiconductors. A brief history of the subject is presented, the trembling motion in semi-relativistic and spin systems is considered and its main features are emphasized. ZB of charge carriers in monolayer and bilayer graphene as well as in carbon nanotubes is elaborated in some detail. We describe the effects of an external magnetic field on ZB using monolayer graphene as an example. The nature of electron ZB in crystalline solids is explained. We also review various simulations of the trembling motion in a vacuum and in semiconductors, and mention ZB-like wave phenomena in sonic and photonic periodic structures. An attempt is made to quote all the relevant literature on the subject.
