Simulation is the imitation of some real thing, state of affairs, or process. The act of simulating something generally entails representing certain key characteristics or behaviours of a selected physical or abstract system.
Simulation is used in many contexts, including the modeling of natural systems or human systems in order to gain insight into their functioning. Other contexts include simulation of technology for performance optimization, safety engineering, testing, training and education. Simulation can be used to show the eventual real effects of alternative conditions and courses of action.
Key issues in simulation include acquisition of valid source information about the relevant selection of key characteristics and behaviours, the use of simplifying approximations and assumptions within the simulation, and fidelity and validity of the simulation outcomes.
A computer simulation (or "sim") is an attempt to model a real-life or hypothetical situation on a computer so that it can be studied to see how the system works. By changing variables, predictions may be made about the behaviour of the system.
Computer simulation has become a useful part of modeling many natural systems in physics, chemistry and biology, and human systems in economics and social science (the computational sociology) as well as in engineering to gain insight into the operation of those systems. A good example of the usefulness of using computers to simulate can be found in the field of network traffic simulation. In such simulations, the model behaviour will change each simulation according to the set of initial parameters assumed for the environment.
Traditionally, the formal modeling of systems has been via a mathematical model, which attempts to find analytical solutions enabling the prediction of the behaviour of the system from a set of parameters and initial conditions. Computer simulation is often used as an adjunct to, or substitution for, modeling systems for which simple closed form analytic solutions are not possible. There are many different types of computer simulation, the common feature they all share is the attempt to generate a sample of representative scenarios for a model in which a complete enumeration of all possible states would be prohibitive or impossible.
Several software packages exist for running computer-based simulation modeling (e.g. Monte Carlo simulation, stochastic modeling, multimethod modeling AnyLogic) that makes the modeling almost effortless.
Modern usage of the term "computer simulation" may encompass virtually any computer-based representation.
Material is synonymous with substance, and is anything made of matter – hydrogen, air and water are all examples of materials. Sometimes the term "material" is used more narrowly to refer to substances or components with certain physical properties that are used as inputs to production or manufacturing. In this sense, materials are the parts required to make something else, from buildings and art to stars and computers.
A material can be anything: a finished product in its own right or an unprocessed raw material. Raw materials are first extracted or harvested from the earth and divided into a form that can be easily transported and stored, then processed to produce semi-finished materials. These can be input into a new cycle of production and finishing processes to create finished materials, ready for distribution, construction, and consumption.
An example of a raw material is cotton, which is harvested from plants. Cotton can be processed into thread (also considered a raw material), which can then be woven into cloth, a semi-finished material. Cutting and sewing the fabric turns it into a garment, which is a finished product. Steelmaking is another example – raw materials in the form of ore are mined, refined and processed into steel, a semi-finished material. Steel is then used as an input in many other industries to make finished products. In chemistry materials can be divided into two metals and non-metals.
Materials science or materials engineering is an interdisciplinary field involving the properties of matter and its applications to various areas of science and engineering. This science investigates the relationship between the structure of materials at atomic or molecular scales and their macroscopic properties. It includes elements of applied physics and chemistry. With significant media attention focused on nanoscience and nanotechnology in recent years, materials science has been propelled to the forefront at many universities. It is also an important part of forensic engineering and failure analysis. The material science also deals with fundamental properties and characteristics of material.
Modelling and Simulation in Materials Science and Engineering is a peer-reviewed scientific journal covering properties, structure and behavior of all classes of materials at scales from the atomic to the macroscopic. This includes electronic structure/properties of materials determined by ab initio and/or semi-empirical methods, atomic level properties of materials, microstructural level phenomena, continuum-level modelling pertaining to material behavior and modelling behavior in service.
