Computer Modeling

FIELDS OF STUDY

Computer Science; Computer Engineering; Software Engineering

ABSTRACT

Computer modeling is the process of designing a representation of a particular system of interacting or interdependent parts in order to study its behavior. Models that have been implemented and executed as computer programs are called computer simulations.

PRINICIPAL TERMS

UNDERSTANDING COMPUTER MODELS

A computer model is a programmed representation of a system that is meant to mimic the behavior of the system. A wide range of disciplines, including meteorology, physics, astronomy, biology, and economics, use computer models to analyze different types of systems. When the program representing the system is executed by a computer, it is called a simulation.

One of the first large-scale computer models was developed during the Manhattan Project by scientists designing and building the first atomic bomb. Early computer models produced output in the form of tables or matrices that were difficult to analyze. It was later discovered that humans can see data trends more easily if the data is presented visually. For example, humans find it easier to analyze the output of a storm-system simulation if it is presented as graphic symbols on a map rather than as a table of meteorological data. Thus, simulations that produced graphic outputs were developed.

Computer models are used when a system is too complex or hard to study using a physical model. For example, it would be difficult if not impossible to create a physical model representing the gravitational effects of planets and moons on each other and on other objects in space.

There are several different types of models. Static models simulate a system at rest, such as a building design. Dynamic models simulate a system that changes over time. A dynamic model could be used to simulate the effects of changing ocean temperatures on the speed of ocean currents throughout the year. A continuous model simulates a system that changes constantly, while a discrete model simulates a system that changes only at specific times. Some models contain both discrete and continuous elements. A farming model might simulate the effects of both weather patterns, which constantly change, and pesticide spraying, which occurs at specified times.

HOW COMPUTER MODELS WORK

To create a computer model, one must first determine the boundaries of the system being modeled and what aspect of the system is being studied. For example, if the model is of the solar system, it might be used to study the potential effect on the orbits of the existing planets if another planet were to enter the solar system.




Mathematical models are used to identify and understand the details influencing a real system. Computer programs allow one to evaluate many variations in a mathematical model quickly and accurately, thus efficiently evaluating and improving models.





Mathematical models are used to identify and understand the details influencing a real system. Computer programs allow one to evaluate many variations in a mathematical model quickly and accurately, thus efficiently evaluating and improving models.
Adapted from Allen and Tildesly, “Computer Simulation of Liquids.

The model must also have a data source from which it will draw the input data. This data may be directly entered into the program or imported from an external source, such as a file, database, or spreadsheet.

WHY COMPUTER MODELS ARE IMPORTANT

Computer models have provided great benefits to society. They help scientists explore the universe, understand the earth, cure diseases, and discover and test new theories. They help engineers design buildings, transportation systems, power systems, and other items that affect everyday life. With the development of more powerful computer systems, computer models will remain an important mechanism for understanding the world and improving the human condition.

—Maura Valentino, MSLIS

SAMPLE PROBLEM

It is important to select appropriate variables and parameters when designing a computer model. List two variables and two parameters that might be used to determine the speed of a baseball after it has traveled three feet from the pitcher's throwing hand.

Answer:

Variables needed to determine the ball's speed might include the mass and size of the ball, the angle at which the ball is released, and the force with which it is thrown.

Parameters that define the system, which may be changed to test different scenarios, include wind speed, aerodynamic drag on the ball, and whether or not it is raining when the ball is thrown.

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