Introduction to Discrete Systems
A discrete system is a system in which all or a key component of a system has discrete signal forms, and the state of the system is mutated at discrete points in time. A variable that takes values at discrete times of time is called a discrete signal, usually a sequence of numbers of equal time intervals, such as data collection at a certain sampling instant. Discrete systems need to be described by difference equations. Discrete system theory is widely used in social, economic, and engineering systems, such as automata, pulse control, sampling adjustment, and digital control. A discrete event dynamic system is a dynamic system that is triggered by event-driven state evolution. The state of such a system usually takes only a limited number of discrete values, corresponding to possible conditions such as the quality of the system components, busyness, and the like. The behavior of the system can be described by the state or sequence of events it produces. Changes in system state are caused by random events such as the appearance or disappearance of certain environmental conditions, certain operations, and the initiation or termination of operations. Because of the lack of operational structure in its state space, it is difficult to study with traditional methods based on differential or difference equations. Experimental research using computer simulation is often the main method.