A simulation is an imitative representation of a process or system that could exist in the real world. In this broad sense, simulation can often be used interchangeably with model. Sometimes a clear distinction between the two terms is made, in which simulations require the use of models; the model represents the key characteristics or behaviors of the selected system or process, whereas the simulation represents the evolution of the model over time. Another way to distinguish between the terms is to define simulation as experimentation with the help of a model. This definition includes time-independent simulations. Often, computers are used to execute the simulation.
A cognitive model is an approximation of one or more cognitive processes in humans or other animals for the purposes of comprehension and prediction. There are many types of cognitive models, and they can range from box-and-arrow diagrams to a set of equations to software programs that interact with the same tools that humans use to complete tasks. In terms of information processing, cognitive modeling is modeling of human perception, reasoning, memory and action.
Social simulation is a research field that applies computational methods to study issues in the social sciences. The issues explored include problems in computational law, psychology, organizational behavior, sociology, political science, economics, anthropology, geography, engineering, archaeology and linguistics.
IDEF, initially an abbreviation of ICAM Definition and renamed in 1999 as Integration Definition, is a family of modeling languages in the field of systems and software engineering. They cover a wide range of uses from functional modeling to data, simulation, object-oriented analysis and design, and knowledge acquisition. These definition languages were developed under funding from U.S. Air Force and, although still most commonly used by them and other military and United States Department of Defense (DoD) agencies, are in the public domain.
An agent-based model (ABM) is a computational model for simulating the actions and interactions of autonomous agents in order to understand the behavior of a system and what governs its outcomes. It combines elements of game theory, complex systems, emergence, computational sociology, multi-agent systems, and evolutionary programming. Monte Carlo methods are used to understand the stochasticity of these models. Particularly within ecology, ABMs are also called individual-based models (IBMs). A review of recent literature on individual-based models, agent-based models, and multiagent systems shows that ABMs are used in many scientific domains including biology, ecology and social science. Agent-based modeling is related to, but distinct from, the concept of multi-agent systems or multi-agent simulation in that the goal of ABM is to search for explanatory insight into the collective behavior of agents obeying simple rules, typically in natural systems, rather than in designing agents or solving specific practical or engineering problems.
SEDRIS is an international data coding standard infrastructure technology created to represent environmental data in virtual environments. Environmental data represented by SEDRIS may be concrete, such as trees and mountains, or abstract, such as the behavior of light. The infrastructure frees users to place their focus on application development and also facilitates the exchange of data for reuse and wider scrutiny. Research into shared ways to represent environmental data was begun in the 1980s in order to permit distributed simulations to work together. SEDRIS was launched in 1994 by program managers of the United States Army's Simulation Training and Instrumentation Command and the US Department of Defense's Defense Advanced Research Projects Agency.
Purdue University's Synthetic Environment for Analysis and Simulations, or SEAS, is currently being used by Homeland Security and the US Defense Department to simulate crises on the US mainland. SEAS "enables researchers and organizations to try out their models or techniques in a publicly known, realistically detailed environment." It "is now capable of running real-time simulations for up to 62 nations, including Iraq, Afghanistan, and China. The simulations gobble up breaking news, census data, economic indicators, and climactic events in the real world, along with proprietary information such as military intelligence. [...] The Iraq and Afghanistan computer models are the most highly developed and complex of the 62 available to JFCOM-J9. Each has about five million individual nodes representing things such as hospitals, mosques, pipelines, and people."
The US DoD Modeling and Simulation Glossary, was originally created in 1998. As of October 2010 the glossary was being updated, without changing its main objective of providing a uniform language for use by the M&S community. This article contains a list of terms and acronyms, based on the original DoD 5000.59-M and information related to the update.
A Synthetic Natural Environment (SNE) is the representation in a synthetic environment of the physical world within which all models of military systems exist and interact. It includes both data and models representing the elements of the environment, their effects on military systems, and models of the impact of military systems on environmental variables.
Modeling and simulation (M&S) is the use of models as a basis for simulations to develop data utilized for managerial or technical decision making.
In a synthetic environment, the synthetic human-made environment (SHME) is the representation of buildings, bridges, roads, and other man-made structures.
In a synthetic environment, Synthetic Psychological Environment (SPE) refers to the representation of influences to individuals and groups as a result of culture ).
A dynamic terrain is the representation of terrain together with the capability for modification during a simulation.
The Simulation Interoperability Standards Organization (SISO) is an organization dedicated to the promotion of modeling and simulation interoperability and reuse for the benefit of diverse modeling and simulation communities, including developers, procurers, and users, worldwide.
Live, Virtual, & Constructive (LVC) Simulation is a broadly used taxonomy for classifying Modeling and Simulation (M&S). However, categorizing a simulation as a live, virtual, or constructive environment is problematic since there is no clear division among these categories. The degree of human participation in a simulation is infinitely variable, as is the degree of equipment realism. The categorization of simulations also lacks a category for simulated people working real equipment.
Human-in-the-loop or HITL is used in multiple contexts. It can be defined as a model requiring human interaction. HITL is associated with modeling and simulation (M&S) in the live, virtual, and constructive taxonomy. HITL along with the related human-on-the-loop are also used in relation to lethal autonomous weapons. Further, HITL is used in the context of machine learning.
Synthetic data is information that's artificially generated rather than produced by real-world events. Typically created using algorithms, synthetic data can be deployed to validate mathematical models and to train machine learning models.
Natural computing, also called natural computation, is a terminology introduced to encompass three classes of methods: 1) those that take inspiration from nature for the development of novel problem-solving techniques; 2) those that are based on the use of computers to synthesize natural phenomena; and 3) those that employ natural materials to compute. The main fields of research that compose these three branches are artificial neural networks, evolutionary algorithms, swarm intelligence, artificial immune systems, fractal geometry, artificial life, DNA computing, and quantum computing, among others.
A virtual human is a software fictional character or human being. Virtual human have been created as tools and artificial companions in simulation, video games, film production, human factors and ergonomic and usability studies in various industries, clothing industry, telecommunications (avatars), medicine, etc. These applications require domain-dependent simulation fidelity. A medical application might require an exact simulation of specific internal organs; film industry requires highest aesthetic standards, natural movements, and facial expressions; ergonomic studies require faithful body proportions for a particular population segment and realistic locomotion with constraints, etc.
