Continuetijd
Continuetijd, literally Dutch for "continuous time," is a concept used to describe models in which time is treated as a continuous variable rather than as a sequence of discrete moments. In Continuetijd models, the state of a system changes smoothly over time, typically described by ordinary differential equations (ODEs) or by stochastic differential equations for random dynamics.
Mathematically, continuous-time dynamical systems are expressed as dx/dt = f(x,t,u(t)) in the deterministic case, or by stochastic
Analysis relies on calculus and transform methods, such as the Laplace transform and Fourier transform, together
Applications of Continuetijd span engineering (control systems, electrical circuits, signal processing), physics (mechanics, quantum dynamics), biology
Real-world data are typically obtained at discrete intervals, so discretization and sampling are essential for estimation