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 Scientific modelling is the process of generating abstract, conceptual, graphical and/or mathematical models. Science offers a growing collection of methods, techniques and theory about all kinds of specialized scientific modelling. Also a way to read elements easily which have been broken down to the simplest form of natural systems or human systems in order to gain insight into their functioning.[1] Other contexts include simulation of technology Technology is the usage and knowledge of tools, techniques, crafts, systems or methods of organization. The word technology comes from the Greek technología — téchnē (τέχνη), an 'art', 'skill' or 'craft' and -logía (-λογία), the study of something, or the branch of knowledge of a discipline. The term can either be applied generally for performance optimization, safety engineering Safety engineering is an applied science strongly related to systems engineering and the subset System Safety Engineering. Safety engineering assures that a life-critical system behaves as needed even when pieces fail, testing Experiments is the step in the scientific method that arbitrates between competing models or hypotheses. Experimentation is also used to test existing theories or new hypotheses in order to support them or disprove them. An experiment or test can be carried out using the scientific method to answer a question or investigate a problem. First an, training The term training refers to the acquisition of knowledge, skills, and competencies as a result of the teaching of vocational or practical skills and knowledge that relate to specific useful competencies. It forms the core of apprenticeships and provides the backbone of content at institutes of technology . In addition to the basic training and education Education in the largest sense is any act or experience that has a formative effect on the mind, character or physical ability of an individual. In its technical sense, education is the process by which society deliberately transmits its accumulated knowledge, skills and values from one generation to another. Simulation can be used to show the eventual real effects of alternative conditions and courses of action. Simulation is also used when the real system cannot be engaged. The real system may not be engaged because it may not be accessible, it may be dangerous or unacceptable to engage, or it may simply not exist [2].
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.
Classification and terminology
Human-in-the-loop simulation of outer space Outer space is the void that exists beyond any celestial body including the Earth. It is not completely empty (i.e. a perfect vacuum), but contains a low density of particles, predominantly hydrogen plasma, as well as electromagnetic radiation, magnetic fields, and neutrinos. Theoretically, it also contains dark matter and dark energy. Visualization of a direct numerical simulation A direct numerical simulation is a simulation in computational fluid dynamics in which the Navier-Stokes equations are numerically solved without any turbulence model. This means that the whole range of spatial and temporal scales of the turbulence must be resolved. All the spatial scales of the turbulence must be resolved in the computational model.Historically, simulations used in different fields developed largely independently, but 20th century studies of Systems theory Systems theory is a transdisciplinary approach, which abstracts and considers a system as a set of independent and interacting parts. The main goal is to study general principles of system functioning to be applied for the all types of systems in all fields of research. As a technical and general academic area of study it predominantly refers to and Cybernetics Cybernetics is the interdisciplinary study of the structure of regulatory systems. Cybernetics is closely related to control theory and systems theory. Both in its origins and in its evolution in the second-half of the 20th century, cybernetics is equally applicable to physical and social systems combined with spreading use of computers across all those fields have led to some unification and a more systematic view of the concept.
Physical simulation refers to simulation in which physical objects are substituted for the real thing (some circles[3] use the term for computer simulations modelling selected laws of physics Physics is a natural science that involves the study of matter and its motion through space-time, as well as all applicable concepts, including energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves, but this article doesn't). These physical objects are often chosen because they are smaller or cheaper than the actual object or system.
Interactive simulation is a special kind of physical simulation, often referred to as a human in the loop simulation, in which physical simulations include human operators, such as in a flight simulator or a driving simulator Driving Simulators are used for entertainment as well as in training of driver's education courses taught in educational institutions and private businesses. They are also used for research purposes in the area of human factors and medical research, to monitor driver behavior, performance, and attention and in the car industry to design and.
Human in the loop simulations can include a computer simulation as a so-called synthetic environment.[4]
Computer simulation
Main article: Computer simulation A computer simulation, a computer model, or a computational model is a computer program, or network of computers, that attempts to simulate an abstract model of a particular system. Computer simulations have become a useful part of mathematical modeling of many natural systems in physics , astrophysics, chemistry and biology, human systems inA 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 A prediction or forecast is a statement about the way things will happen in the future, often but not always based on experience or knowledge. While there is much overlap between prediction and forecast, a prediction may be a statement that some outcome is expected, while a forecast may cover a range of possible outcomes may be made about the behaviour of the system.[1]
Computer simulation has become a useful part of modeling In the most general sense, a model is anything used in any way to represent anything else. Some models are physical objects, for instance, a toy model which may be assembled, and may even be made to work like the object it represents. However a conceptual model, may only be drawn on paper, described in words, or imagined in the mind. They are used many natural systems in physics Physics is a natural science that involves the study of matter and its motion through space-time, as well as all applicable concepts, including energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves, chemistry Chemistry is the science of matter and the changes it undergoes. The science of matter is also addressed by physics, but while physics takes a more general and fundamental approach, chemistry is more specialized, being concerned with the composition, behavior, structure, and properties of matter, as well as the changes it undergoes during chemical and biology Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy[5], and human systems in economics Economics is the social science that analyzes the production, distribution, and consumption of goods and services. The term economics comes from the Ancient Greek οἰκονομία from οἶκος (oikos, "house") + νόμος (nomos, "custom" or "law"), hence "rules of the house(hold)". Current economic and social science The social sciences are the fields of academic scholarship that explore aspects of human society. "Social science" is commonly used as an umbrella term to refer to a plurality of fields outside of the natural sciences. These include: anthropology, archaeology, economics, geography, history, linguistics, political science, international (the computational sociology Computational sociology is a branch of sociology that uses computationally-intensive methods to analyze and model social phenomena. Using computer simulations, artificial intelligence, complex statistical methods, and new analytic approaches like social network analysis, computational sociology develops and tests theories of complex social) as well as in engineering Engineering is the discipline, art and profession of acquiring and applying technical, scientific, and mathematical knowledge to design and implement materials, structures, machines, devices, systems, and processes that safely realize a desired objective or invention 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 Telecommunications systems are complex real-world system, containing many different components which interact, in complex interrelationships. The analysis of such a system can become extremely difficult: modelling techniques tend to analyse each component rather than the relationships between components. Simulation is an approach which can be used. In such simulations, the model In the most general sense, a model is anything used in any way to represent anything else. Some models are physical objects, for instance, a toy model which may be assembled, and may even be made to work like the object it represents. However a conceptual model, may only be drawn on paper, described in words, or imagined in the mind. They are used 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 A mathematical model uses mathematical language to describe a system. The process of developing a mathematical model is termed mathematical modelling . Mathematical models are used not only in the natural sciences (such as physics, biology, earth science, meteorology) and engineering disciplines, but also in the social sciences (such as economics,, 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 In mathematics, an expression is said to be a closed-form expression if, and only if, it can be expressed analytically in terms of a bounded number of certain "well-known" functions. Typically, these well-known functions are defined to be elementary functions – constants, one variable x, elementary operations of arithmetic , nth roots, 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 A scenario is a synthetic description of an event or series of actions and events. In the Commedia dell'arte it was an outline of entrances, exits, and action describing the plot of a play that was literally pinned to the back of the scenery. It is also known as canovaccio or "that which is pinned to the canvas" of which the scenery was 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 Monte Carlo methods are a class of computational algorithms that rely on repeated random sampling to compute their results. Monte Carlo methods are often used in simulating physical and mathematical systems. Because of their reliance on repeated computation of random or pseudo-random numbers, these methods are most suited to calculation by a simulation, stochastic modeling Stochastic means random. A stochastic process is one whose behavior is non-deterministic, in that a system's subsequent state is determined both by the process's predictable actions and by a random element. However, according to M. Kac and E. Nelson, any kind of time development (be it deterministic or essentially probabilistic) which is, multimethod modeling) that makes the modeling almost effortless.
Modern usage of the term "computer simulation" may encompass virtually any computer-based representation.
Computer science
In computer science Computer science or computing science is the study of the theoretical foundations of information and computation, and of practical techniques for their implementation and application in computer systems. It is frequently described as the systematic study of algorithmic processes that create, describe, and transform information. Computer science, simulation has some specialized meanings: Alan Turing Alan Mathison Turing, OBE, FRS , was an English mathematician, logician, cryptanalyst and computer scientist. He was influential in the development of computer science and providing a formalisation of the concept of the algorithm and computation with the Turing machine, playing a significant role in the creation of the modern computer used the term "simulation" to refer to what happens when a universal machine In computer science, a universal Turing machine is a Turing machine that can simulate an arbitrary Turing machine on arbitrary input. Alan Turing introduced this machine in 1936-1937. This model is considered by some (for example, Martin Davis ) to be the origin of the stored program computer -- used by John von Neumann (1946) for his " executes a state transition table (in modern terminology, a computer runs a program) that describes the state transitions, inputs and outputs of a subject discrete-state machine. The computer simulates the subject machine. Accordingly, in theoretical computer science Theoretical computer science is a branch of computer science that focuses on the more abstract, logical and mathematical aspects of computing, such as the theory of computation, analysis of algorithms, and semantics of programming languages. Although not itself a single topic, its practitioners form a distinct subgroup within computer science the term simulation is a relation between state transition systems, useful in the study of operational semantics In computer science, operational semantics is a way to give meaning to computer programs in a mathematically rigorous way. Other approaches to providing a formal semantics of programming languages include axiomatic semantics and denotational semantics.
Less theoretically, an interesting application of computer simulation is to simulate computers using computers. In computer architecture In computer science and computer engineering, computer architecture or digital computer organization is the conceptual design and fundamental operational structure of a computer system. It is a blueprint and functional description of requirements and design implementations for the various parts of a computer, focusing largely on the way by which, a type of simulator, typically called an emulator An emulator in computer sciences duplicates the functions of one system using a different system, so that the second system behaves like (and appears to be) the first system. This focus on exact reproduction of external behavior is in contrast to some other forms of computer simulation, which can concern an abstract model of the system being, is often used to execute a program that has to run on some inconvenient type of computer (for example, a newly designed computer that has not yet been built or an obsolete computer that is no longer available), or in a tightly controlled testing environment (see Computer architecture simulator and Platform virtualization In computing, hardware virtualization is a virtualization of computers or operating systems. It hides the physical characteristics of a computing platform from users, instead showing another abstract computing platform). For example, simulators have been used to debug a microprogram Microcode is a layer of hardware-level instructions and/or data structures involved in the implementation of higher level machine code instructions in many computers and other processors; it resides in a special high-speed memory and translates machine instructions into sequences of detailed circuit-level operations. It helps separate the machine or sometimes commercial application programs, before the program is downloaded to the target machine. Since the operation of the computer is simulated, all of the information about the computer's operation is directly available to the programmer, and the speed and execution of the simulation can be varied at will.
Simulators may also be used to interpret fault trees Fault tree analysis is a failure analysis in which an undesired state of a system is analyzed using boolean logic to combine a series of lower-level events. This analysis method is mainly used in the field of safety engineering to quantitatively determine the probability of a safety hazard, or test VLSI Very-large-scale integration is the process of creating integrated circuits by combining thousands of transistors into a single chip. VLSI began in the 1970s when complex semiconductor and communication technologies were being developed. The microprocessor is a VLSI device. The term is no longer as common as it once was, as chips have increased in logic designs before they are constructed. Symbolic simulation In computer science, a simulation is a computation of the execution of some appropriately modelled state-transition system. Typically this process models the complete state of the system at individual points in a discrete linear time frame, computing each state sequentially from its predecessor. Models for computer programs or VLSI logic designs uses variables to stand for unknown values.
In the field of optimization In mathematics and computer science, optimization, or mathematical programming, refers to choosing the best element from some set of available alternatives, simulations of physical processes are often used in conjunction with evolutionary computation In computer science, evolutionary computation is a subfield of artificial intelligence that involves combinatorial optimization problems to optimize control strategies.
Wed, 25 Aug 2010 14:42:27 GMT+00:00
EOG.com The Red Sox have a better than 55% chance of winning based on 1000 game simulations generated one play at a time by the AccuScore Simulation Supercomputer. ...
Tue, 01 Jan 2008 19:25:51 PST
How to pass... using Buzzball Pass Simulation style of stick passing.. youtube.com.
