Dynamical Systems and Modeling

Abstract

A system is an isolated part of the Universe that is of interest due to a specific reason for an appropriate time. This isolated reality can be used for discussion, study, analysis, improvement, betterment, protection, or any other objective. The isolated part in which we take interest actually becomes the system and everything else is surroundings, environment, or the rest of the Universe. For example, an astrophysicist wants to study the gravitational forces of the sun and its planets, so this isolated interest becomes a solar system for him. The rest of the galaxies, and even relatively small events on the earth and planets, become surroundings for him. An oceanographer analyzing the waves and currents in the Pacific is only interested in his isolated reality and the rest of the happenings in the world are collectively an environment. Similarly, an engineer working on a comparatively small problem whether designing, studying, or discussing is a system for him and everything else in the world becomes an environment or surroundings to him till he stops working. A car is a system, an isolated part of reality for a buyer. But this car itself is a combination of many other systems such as a combustion system, braking system, fuel injection system, electrical system, steering systems, etc. A buyer at a time is interested in all including the color of car, financial value in the market, fuel consumption, etc. He is overall looking for an appropriate driving system that suits his needs. But several different types of engineers are interested in several subsystems of the same car. This car in turn is a collection of subsystems. A subsystem is a complete system when one develops an interest in it and other subsystems of the same car become an environment or surroundings for it. This example is similar to the human body system with several subsystems like the respiratory system, digestive system, reproductive system, central nervous system, etc. A body needs all subsystems at a time but an orthopedic surgeon usually only focuses on the skeletal system, and a gastroenterologist is only interested in the digestive system.