Simulation And Stochastic Models

SIMULATION: ❏ Simulation is the imitation of the operation of a realworld process or system over time. ❏ The act of simulating something first requires that a model be developed; this model represents the key characteristics or behaviors/functions of the selected physical or abstract system or process. ❏ The model represents the system itself, whereas the simulation represents the operation of the system over time.

Simulation is used in many contexts such as: ➢ ➢ ➢ ➢ ➢ ➢

simulation of technology for performance optimization safety engineering testing training education video games

➢ Often, computer experiments are used to study simulation models. Simulation is also used with scientific modelling of natural systems or human systems to gain insight into their functioning.

CLASSIFICATION OF SIMULATIONS: ❏ Physical simulation refers to simulation in which physical objects are substituted for the real thing i.e., computer simulations modelling selected laws of physics. ❏ 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 driving simulator.

❏ Human in the loop simulations can include a computer simulation as a so-called synthetic environment. ❏ Simulation in failure analysis refers to simulation in which we create environment/conditions to identify the cause of equipment failure. This was the best and fastest method to identify the failure cause.

COMPUTER SIMULATION: ❏ 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 in the simulation, predictions may be made about the behaviour of the system. ❏ It is a tool to virtually investigate the behaviour of the system under study.

USES OF COMPUTER SIMULATION: ● Modeling of natural systems in Physics, Chemistry and Biology. ● Human systems in Economics and Social Science. ● In Engineering, to gain insight into the operation of the natural and human systems. ● Network traffic simulations where the model behaviour changes for each simulation. ● In the field of Cybertherapy, to make the patients overcome traumatic experiences, from fear of heights to social anxiety.

Simulation in education and training: ● Simulation is extensively used for educational purposes. It is frequently used by way of adaptive hypermedia. ● Simulation is often used in the training of civilian and military personnel.This usually occurs when it is prohibitively expensive or simply too dangerous to allow trainees to use the real equipment in the real world.

VIRTUAL SIMULATIONS: ➔ Virtual simulations represent a specific category of simulation that utilizes simulation equipment to create a simulated world for the user.They allow users to interact with a virtual world. ➔ Virtual worlds operate on platforms of integrated software and hardware components. In this manner, the system can accept input from the user (e.g., body tracking, voice/sound recognition, physical controllers) and produce output to the user (e.g., visual display, aural display, haptic display) . [15] ➔ Virtual Simulations use the aforementioned modes of interaction to produce a sense of immersion for the user.

VIRTUAL SIMULATION INPUT HARDWARE: Body tracking: The motion capture method is often used to record the user’s movements and translate the captured data into inputs for the virtual simulation. For example, if a user physically turns their head, the motion would be captured by the simulation hardware in some way and translated to a corresponding shift in view within the simulation. ● Capture suits and/or gloves may be used to capture movements of users body parts. ● Eye trackers can also be used to detect eye movements so that the system can determine precisely where a user is looking at any given instant.

Physical controllers: ●

Physical controllers provide input to the simulation only through direct manipulation by the user. In virtual simulations, tactile feedback from physical controllers is highly desirable in a number of simulation environments. ● Omni directional treadmills can be used to capture the users locomotion as they walk or run.

Voice/sound recognition: ● This form of interaction may be used either to interact with agents within the simulation (e.g., virtual people) or to manipulate objects in the simulation (e.g., information). ● Users may use headsets with boom microphones, lapel microphones or the room may be equipped with strategically located microphones.

Conclusion: Training a human to be adaptable under stress is elusive without the actual situation. Classroom instruction will never be able to fill the knowledge gap between school and reality. Simulation, on the other hand, can erase common mistakes and bring a student closer to the reality experience. It is not the physical reality that provides the immersive environment for the participant, but the cognitive realism afforded by complex and engaging tasks. The exposure to and completion of the tasks (afforded by the simulation) develop the necessary knowledge and skills which are transferable to the “live” context.

Learning by doing, peer-to-peer teach ing, and computer simulation are all part of the same equation.

~Nicholas Negroponte

STOCHASTIC SYSTEMS: ❏ Physical systems in which we are uncertain about the values of parameters, measurements, expected input and disturbances are termed Stochastic Systems. ❏ In probability theory, a purely stochastic system is one whose state is randomly determined, having a random probability distribution or pattern that may be analyzed statistically but may not be predicted precisely.

❏ In this regard, it can be classified as non-deterministic (i.e., "random") so that the subsequent state of the system is determined probabilistically. ❏ Any system or process that must be analyzed using probability theory is stochastic at least in part.

FIELDS DEALT BY STOCHASTIC SYSTEMS: ➢ Stochastic systems and processes play a fundamental role in mathematical models of phenomena in many fields of science, engineering, and economics. ➢ Training and research in mathematical finance. ➢ In various engineering disciplines like power systems, robotics, automotive technology, signal processing, manufacturing systems, semiconductor manufacturing, communication networks, wireless networks etc. ➢ In the field of neuroscience

❏ Mathematics:

In mathematics, specifically in probability theory, the field of stochastic processes has been a major area of research. A stochastic matrix is a matrix that has non-negative real entries that sum to one in each column, row, or both.

❏ Artificial intelligence: In AI, stochastic programs work by using probabilistic methods to solve problems, as in simulated annealing, stochastic neural networks, stochastic optimization,genetic algorithms and genetic programming.

❏ Computer science Although most computers are deterministic machines, their complexity makes deterministic analysis impossible. Consequently, stochastic forensics analyzes computer crime by viewing computers as stochastic processes.

❏ Music In music,mathematical processes based on probability can generate stochastic elements. Stochastic processes may be used in music to compose a fixed piece or may be produced in performance.

Few other fields in which Stochastic models are used: ➢ Natural Science ➢ Color reproduction ➢ Language and linguistics ➢ Social sciences ➢ Business ➢ Oil reservoirs ● Stochastic methods are widely used for uncertainty assessment in future performance predictions of oil and gas reservoirs