The metal-oxide-semiconductor field-effect transistor is a type of field-effect transistor, most fabricated by the controlled oxidation of silicon. It has an insulated gate; this ability to change conductivity with the amount of applied voltage can be used for amplifying or switching electronic signals. A metal-insulator-semiconductor field-effect transistor or MISFET is a term synonymous with MOSFET. Another synonym is IGFET for insulated-gate field-effect transistor; the basic principle of the field-effect transistor was first patented by Julius Edgar Lilienfeld in 1925. The main advantage of a MOSFET is that it requires no input current to control the load current, when compared with bipolar transistors. In an enhancement mode MOSFET, voltage applied to the gate terminal increases the conductivity of the device. In depletion mode transistors, voltage applied at the gate reduces the conductivity; the "metal" in the name MOSFET is sometimes a misnomer, because the gate material can be a layer of polysilicon.
"oxide" in the name can be a misnomer, as different dielectric materials are used with the aim of obtaining strong channels with smaller applied voltages. The MOSFET is by far the most common transistor in digital circuits, as billions may be included in a memory chip or microprocessor. Since MOSFETs can be made with either p-type or n-type semiconductors, complementary pairs of MOS transistors can be used to make switching circuits with low power consumption, in the form of CMOS logic; the basic principle of this kind of transistor was first patented by Julius Edgar Lilienfeld in 1925. In 1959, Dawon Kahng and Martin M. Atalla at Bell Labs invented the metal-oxide-semiconductor field-effect transistor as an offshoot to the patented FET design. Operationally and structurally different from the bipolar junction transistor, the MOSFET was made by putting an insulating layer on the surface of the semiconductor and placing a metallic gate electrode on that, it used crystalline silicon for the semiconductor and a thermally oxidized layer of silicon dioxide for the insulator.
The silicon MOSFET did not generate localized electron traps at the interface between the silicon and its native oxide layer, thus was inherently free from the trapping and scattering of carriers that had impeded the performance of earlier field-effect transistors. The semiconductor of choice is silicon; some chip manufacturers, most notably IBM and Intel, have started using a chemical compound of silicon and germanium in MOSFET channels. Many semiconductors with better electrical properties than silicon, such as gallium arsenide, do not form good semiconductor-to-insulator interfaces, thus are not suitable for MOSFETs. Research continues on creating insulators with acceptable electrical characteristics on other semiconductor materials. To overcome the increase in power consumption due to gate current leakage, a high-κ dielectric is used instead of silicon dioxide for the gate insulator, while polysilicon is replaced by metal gates; the gate is separated from the channel by a thin insulating layer, traditionally of silicon dioxide and of silicon oxynitride.
Some companies have started to introduce a high-κ dielectric and metal gate combination in the 45 nanometer node. When a voltage is applied between the gate and body terminals, the electric field generated penetrates through the oxide and creates an inversion layer or channel at the semiconductor-insulator interface; the inversion layer provides a channel through which current can pass between source and drain terminals. Varying the voltage between the gate and body modulates the conductivity of this layer and thereby controls the current flow between drain and source; this is known as enhancement mode. The traditional metal-oxide-semiconductor structure is obtained by growing a layer of silicon dioxide on top of a silicon substrate and depositing a layer of metal or polycrystalline silicon; as the silicon dioxide is a dielectric material, its structure is equivalent to a planar capacitor, with one of the electrodes replaced by a semiconductor. When a voltage is applied across a MOS structure, it modifies the distribution of charges in the semiconductor.
If we consider a p-type semiconductor, a positive voltage, V GB, from gate to body creates a depletion layer by forcing the positively charged holes away from the gate-insulator/semiconductor interface, leaving exposed a carrier-free region of immobile, negatively charged acceptor ions. If V GB is high enough, a high concentration of negative charge carriers forms in an inversion layer located in a thin layer next to the interface between the semiconductor and the insulator. Conventionally, the gate voltage at which the volume density of electrons in the inversion layer is the same as the volume density of holes in the body is called the threshold voltage; when the voltage between transistor gate and source exceeds the threshold voltage, the difference is known as overdrive voltage. This structure with p-type body is the basis of the n-type MOSFET, which requires the addition of n-type source and drain regions; the MOS capacitor structure is the heart of the MOSFET. Let's consider a MOS capacitor.
If a positive voltage is applied at
Newline is a control character or sequence of control characters in a character encoding specification, used to signify the end of a line of text and the start of a new one. Text editors set this special character; when displaying a text file, this control character causes the text editor to show the following characters in a new line. In the mid-1800s, long before the advent of teleprinters and teletype machines, Morse code operators or telegraphists invented and used Morse code prosigns to encode white space text formatting in formal written text messages. In particular the Morse prosign represented by the concatenation of two literal textual Morse code "A" characters sent without the normal inter-character spacing is used in Morse code to encode and indicate a new line in a formal text message. In the age of modern teleprinters standardized character set control codes were developed to aid in white space text formatting. ASCII was developed by the International Organization for Standardization and the American Standards Association, the latter being the predecessor organization to American National Standards Institute.
During the period of 1963 to 1968, the ISO draft standards supported the use of either CR+LF or LF alone as a newline, while the ASA drafts supported only CR+LF. The sequence CR+LF was used on many early computer systems that had adopted Teletype machines—typically a Teletype Model 33 ASR—as a console device, because this sequence was required to position those printers at the start of a new line; the separation of newline into two functions concealed the fact that the print head could not return from the far right to the beginning of the next line in time to print the next character. Any character printed after a CR would print as a smudge in the middle of the page while the print head was still moving the carriage back to the first position. "The solution was to make the newline two characters: CR to move the carriage to column one, LF to move the paper up." In fact, it was necessary to send extra characters—extraneous CRs or NULs—which are ignored but give the print head time to move to the left margin.
Many early video displays required multiple character times to scroll the display. On such systems, applications had to talk directly to the Teletype machine and follow its conventions since the concept of device drivers hiding such hardware details from the application was not yet well developed. Therefore, text was composed to satisfy the needs of Teletype machines. Most minicomputer systems from DEC used this convention. CP/M used it in order to print on the same terminals that minicomputers used. From there MS-DOS adopted CP/M's CR+LF in order to be compatible, this convention was inherited by Microsoft's Windows operating system; the Multics operating system used LF alone as its newline. Multics used a device driver to translate this character to whatever sequence a printer needed, the single byte was more convenient for programming. What seems like a more obvious choice—CR—was not used, as CR provided the useful function of overprinting one line with another to create boldface and strikethrough effects.
More the use of LF alone as a line terminator had been incorporated into drafts of the eventual ISO/IEC 646 standard. Unix followed the Multics practice, Unix-like systems followed Unix; the concepts of line feed and carriage return are associated, can be considered either separately or together. In the physical media of typewriters and printers, two axes of motion, "down" and "across", are needed to create a new line on the page. Although the design of a machine must consider them separately, the abstract logic of software can combine them together as one event; this is why a newline in character encoding can be defined as CR combined into one. Some character sets provide a separate newline character code. EBCDIC, for example, provides an NL character code in addition to the LF codes. Unicode, in addition to providing the ASCII CR and LF control codes provides a "next line" control code, as well as control codes for "line separator" and "paragraph separator" markers. Software applications and operating systems represent a newline with one or two control characters: EBCDIC systems—mainly IBM mainframe systems, including z/OS and i5/OS —use NL as the character combining the functions of line-feed and carriage-return.
The equivalent UNICODE character is called NEL. EBCDIC has control characters called CR and LF, but the numerical value of LF differs from the one used by ASCII. Additionally, some EBCDIC variants use NL but assign a different numeric code to the character. However, those operating systems use a record-based file system, which stores text files as one record per line. In most file formats, no line terminators are stored. Operating systems for the CDC 6000 series defined a newline as two or more zero-valued six-bit characters at the end of a 60-bit word; some configurations defined a zero-valued character as a colon character, with the result that multiple colons could be interpreted as a newline depending on position. RSX-11 and OpenVMS use a record-based file system, which stores text files as one record per line. In most file formats, no line terminators are stored, but the Record Management Services facility can transparently add a terminator to each line when it is retrieved by
An integrated circuit or monolithic integrated circuit is a set of electronic circuits on one small flat piece of semiconductor material, silicon. The integration of large numbers of tiny transistors into a small chip results in circuits that are orders of magnitude smaller and faster than those constructed of discrete electronic components; the IC's mass production capability and building-block approach to circuit design has ensured the rapid adoption of standardized ICs in place of designs using discrete transistors. ICs are now used in all electronic equipment and have revolutionized the world of electronics. Computers, mobile phones, other digital home appliances are now inextricable parts of the structure of modern societies, made possible by the small size and low cost of ICs. Integrated circuits were made practical by mid-20th-century technology advancements in semiconductor device fabrication. Since their origins in the 1960s, the size and capacity of chips have progressed enormously, driven by technical advances that fit more and more transistors on chips of the same size – a modern chip may have many billions of transistors in an area the size of a human fingernail.
These advances following Moore's law, make computer chips of today possess millions of times the capacity and thousands of times the speed of the computer chips of the early 1970s. ICs have two main advantages over discrete circuits: performance. Cost is low because the chips, with all their components, are printed as a unit by photolithography rather than being constructed one transistor at a time. Furthermore, packaged ICs use much less material than discrete circuits. Performance is high because the IC's components switch and consume comparatively little power because of their small size and close proximity; the main disadvantage of ICs is the high cost to fabricate the required photomasks. This high initial cost means. An integrated circuit is defined as: A circuit in which all or some of the circuit elements are inseparably associated and electrically interconnected so that it is considered to be indivisible for the purposes of construction and commerce. Circuits meeting this definition can be constructed using many different technologies, including thin-film transistors, thick-film technologies, or hybrid integrated circuits.
However, in general usage integrated circuit has come to refer to the single-piece circuit construction known as a monolithic integrated circuit. Arguably, the first examples of integrated circuits would include the Loewe 3NF. Although far from a monolithic construction, it meets the definition given above. Early developments of the integrated circuit go back to 1949, when German engineer Werner Jacobi filed a patent for an integrated-circuit-like semiconductor amplifying device showing five transistors on a common substrate in a 3-stage amplifier arrangement. Jacobi disclosed cheap hearing aids as typical industrial applications of his patent. An immediate commercial use of his patent has not been reported; the idea of the integrated circuit was conceived by Geoffrey Dummer, a radar scientist working for the Royal Radar Establishment of the British Ministry of Defence. Dummer presented the idea to the public at the Symposium on Progress in Quality Electronic Components in Washington, D. C. on 7 May 1952.
He gave many symposia publicly to propagate his ideas and unsuccessfully attempted to build such a circuit in 1956. A precursor idea to the IC was to create small ceramic squares, each containing a single miniaturized component. Components could be integrated and wired into a bidimensional or tridimensional compact grid; this idea, which seemed promising in 1957, was proposed to the US Army by Jack Kilby and led to the short-lived Micromodule Program. However, as the project was gaining momentum, Kilby came up with a new, revolutionary design: the IC. Newly employed by Texas Instruments, Kilby recorded his initial ideas concerning the integrated circuit in July 1958 demonstrating the first working integrated example on 12 September 1958. In his patent application of 6 February 1959, Kilby described his new device as "a body of semiconductor material … wherein all the components of the electronic circuit are integrated." The first customer for the new invention was the US Air Force. Kilby won the 2000 Nobel Prize in Physics for his part in the invention of the integrated circuit.
His work was named an IEEE Milestone in 2009. Half a year after Kilby, Robert Noyce at Fairchild Semiconductor developed a new variety of integrated circuit, more practical than Kilby's implementation. Noyce's design was made of silicon. Noyce credited Kurt Lehovec of Sprague Electric for the principle of p–n junction isolation, a key concept behind the IC; this isolation allows each transistor to operate independently despite being part of the same piece of silicon. Fairchild Semiconductor was home of the first silicon-gate IC technology with self-aligned gates, the basis of all modern CMOS integrated circuits; the technology was developed by Italian physicist Federico Faggin in 1968. In 1970, he joined Intel in order to develop the first single-chip central processing unit microprocessor, the Intel 4004, for which he received the National Medal of Technology and Innovation in 2010; the 4004 was designed by Busicom's Masatoshi Shima and Intel's Ted Hoff in 1969, but it was Faggin's improved design in 1970 that made it a reality.
Advances in IC technology smaller features and la
An electronic component is any basic discrete device or physical entity in an electronic system used to affect electrons or their associated fields. Electronic components are industrial products, available in a singular form and are not to be confused with electrical elements, which are conceptual abstractions representing idealized electronic components. Electronic components leads; these leads connect to create an electronic circuit with a particular function. Basic electronic components may be packaged discretely, as arrays or networks of like components, or integrated inside of packages such as semiconductor integrated circuits, hybrid integrated circuits, or thick film devices; the following list of electronic components focuses on the discrete version of these components, treating such packages as components in their own right. Components can be classified as active, or electromechanic; the strict physics definition treats passive components as ones that cannot supply energy themselves, whereas a battery would be seen as an active component since it acts as a source of energy.
However, electronic engineers who perform circuit analysis use a more restrictive definition of passivity. When only concerned with the energy of signals, it is convenient to ignore the so-called DC circuit and pretend that the power supplying components such as transistors or integrated circuits is absent, though it may in reality be supplied by the DC circuit; the analysis only concerns the AC circuit, an abstraction that ignores DC voltages and currents present in the real-life circuit. This fiction, for instance, lets us view an oscillator as "producing energy" though in reality the oscillator consumes more energy from a DC power supply, which we have chosen to ignore. Under that restriction, we define the terms as used in circuit analysis as: Active components rely on a source of energy and can inject power into a circuit, though this is not part of the definition. Active components include amplifying components such as transistors, triode vacuum tubes, tunnel diodes. Passive components can't introduce net energy into the circuit.
They can't rely on a source of power, except for what is available from the circuit they are connected to. As a consequence they can't amplify, although they may increase current. Passive components include two-terminal components such as resistors, capacitors and transformers. Electromechanical components can carry out electrical operations by using moving parts or by using electrical connectionsMost passive components with more than two terminals can be described in terms of two-port parameters that satisfy the principle of reciprocity—though there are rare exceptions. In contrast, active components lack that property. Conduct electricity in one direction, among more specific behaviors. Diode, diode bridge Schottky diode – super fast diode with lower forward voltage drop Zener diode – passes current in reverse direction to provide a constant voltage reference Transient voltage suppression diode, unipolar or bipolar – used to absorb high-voltage spikes Varicap, tuning diode, variable capacitance diode – a diode whose AC capacitance varies according to the DC voltage applied.
Light-emitting diode – a diode that emits light Photodiode – passes current in proportion to incident light Avalanche photodiode – photodiode with internal gain Solar Cell, photovoltaic cell, PV array or panel – produces power from light DIAC, Trigger Diode, SIDAC) – used to trigger an SCR Constant-current diode Peltier cooler – a semiconductor heat pump Tunnel diode - fast diode based on quantum mechanical tunneling Transistors were considered the invention of the twentieth century that changed electronic circuits forever. A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. Transistors Bipolar junction transistor – NPN or PNP Photo transistor – amplified photodetector Darlington transistor – NPN or PNP Photo Darlington – amplified photodetector Sziklai pair Field-effect transistor JFET – N-CHANNEL or P-CHANNEL MOSFET – N-CHANNEL or P-CHANNEL MESFET HEMT Thyristors Silicon-controlled rectifier – passes current only after triggered by a sufficient control voltage on its gate TRIAC – bidirectional SCR Unijunction transistor Programmable Unijunction transistor SIT SITh Composite transistors IGBT Digital electronics Analog Hall effect sensor – senses a magnetic field Current sensor – senses a current through it Opto-electronics Opto-isolator, opto-coupler, photo-coupler – photodiode, BJT, JFET, SCR, TRIAC, zero-crossing TRIAC, open collector IC, CMOS IC, solid state relay Slotted optical switch, opto switch, optical switch LED display – seven-segment display, sixteen-segment display, dot-matrix display Current: Filament lamp Vacuum fluorescent display Cathode ray tube (monochro
A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, terminate transmission lines, among other uses. High-power resistors that can dissipate many watts of electrical power as heat, may be used as part of motor controls, in power distribution systems, or as test loads for generators. Fixed resistors have resistances that only change with temperature, time or operating voltage. Variable resistors can be used to adjust circuit elements, or as sensing devices for heat, humidity, force, or chemical activity. Resistors are common elements of electrical networks and electronic circuits and are ubiquitous in electronic equipment. Practical resistors as discrete components can be composed of various forms. Resistors are implemented within integrated circuits; the electrical function of a resistor is specified by its resistance: common commercial resistors are manufactured over a range of more than nine orders of magnitude.
The nominal value of the resistance falls within the manufacturing tolerance, indicated on the component. Two typical schematic diagram symbols are as follows: The notation to state a resistor's value in a circuit diagram varies. One common scheme is the RKM code following IEC 60062, it avoids using a decimal separator and replaces the decimal separator with a letter loosely associated with SI prefixes corresponding with the part's resistance. For example, 8K2 as part marking code, in a circuit diagram or in a bill of materials indicates a resistor value of 8.2 kΩ. Additional zeros imply a tighter tolerance, for example 15M0 for three significant digits; when the value can be expressed without the need for a prefix, an "R" is used instead of the decimal separator. For example, 1R2 indicates 1.2 Ω, 18R indicates 18 Ω. The behaviour of an ideal resistor is dictated by the relationship specified by Ohm's law: V = I ⋅ R. Ohm's law states that the voltage across a resistor is proportional to the current, where the constant of proportionality is the resistance.
For example, if a 300 ohm resistor is attached across the terminals of a 12 volt battery a current of 12 / 300 = 0.04 amperes flows through that resistor. Practical resistors have some inductance and capacitance which affect the relation between voltage and current in alternating current circuits; the ohm is the SI unit of electrical resistance, named after Georg Simon Ohm. An ohm is equivalent to a volt per ampere. Since resistors are specified and manufactured over a large range of values, the derived units of milliohm and megohm are in common usage; the total resistance of resistors connected in series is the sum of their individual resistance values. R e q = R 1 + R 2 + ⋯ + R n; the total resistance of resistors connected in parallel is the reciprocal of the sum of the reciprocals of the individual resistors. 1 R e q = 1 R 1 + 1 R 2 + ⋯ + 1 R n. For example, a 10 ohm resistor connected in parallel with a 5 ohm resistor and a 15 ohm resistor produces 1/1/10 + 1/5 + 1/15 ohms of resistance, or 30/11 = 2.727 ohms.
A resistor network, a combination of parallel and series connections can be broken up into smaller parts that are either one or the other. Some complex networks of resistors cannot be resolved in this manner, requiring more sophisticated circuit analysis; the Y-Δ transform, or matrix methods can be used to solve such problems. At any instant, the power P consumed by a resistor of resistance R is calculated as: P = I 2 R = I V = V 2 R where V is the voltage across the resistor and I is the current flowing through it. Using Ohm's law, the two other forms can be derived; this power is converted into heat which must be dissipated by the resistor's package before its temperature rises excessively. Resistors are rated according to their maximum power dissipation. Discrete resistors in solid-state electronic systems are rated as 1/10, 1/8, or 1/4 watt, they absorb much less than a watt of electrical power and require little attention to their power rating. Resistors required to dissipate substantial amounts of power used in power supplies, power conversion circuits, power amplifiers, are referred to as power resistors.
Power resistors are physically larger and may not use the preferred values, color codes, external packages described below. If the average power dissipated by a resistor is more than its power rating, damage to the resistor may occur, permanently altering its resistance. Excessive power dissip
A capacitor is a passive two-terminal electronic component that stores electrical energy in an electric field. The effect of a capacitor is known as capacitance. While some capacitance exists between any two electrical conductors in proximity in a circuit, a capacitor is a component designed to add capacitance to a circuit; the capacitor was known as a condenser or condensator. The original name is still used in many languages, but not in English; the physical form and construction of practical capacitors vary and many capacitor types are in common use. Most capacitors contain at least two electrical conductors in the form of metallic plates or surfaces separated by a dielectric medium. A conductor may be sintered bead of metal, or an electrolyte; the nonconducting dielectric acts to increase the capacitor's charge capacity. Materials used as dielectrics include glass, plastic film, mica and oxide layers. Capacitors are used as parts of electrical circuits in many common electrical devices. Unlike a resistor, an ideal capacitor does not dissipate energy.
When two conductors experience a potential difference, for example, when a capacitor is attached across a battery, an electric field develops across the dielectric, causing a net positive charge to collect on one plate and net negative charge to collect on the other plate. No current flows through the dielectric. However, there is a flow of charge through the source circuit. If the condition is maintained sufficiently long, the current through the source circuit ceases. If a time-varying voltage is applied across the leads of the capacitor, the source experiences an ongoing current due to the charging and discharging cycles of the capacitor. Capacitance is defined as the ratio of the electric charge on each conductor to the potential difference between them; the unit of capacitance in the International System of Units is the farad, defined as one coulomb per volt. Capacitance values of typical capacitors for use in general electronics range from about 1 picofarad to about 1 millifarad; the capacitance of a capacitor is proportional to the surface area of the plates and inversely related to the gap between them.
In practice, the dielectric between the plates passes a small amount of leakage current. It has an electric field strength limit, known as the breakdown voltage; the conductors and leads introduce an undesired resistance. Capacitors are used in electronic circuits for blocking direct current while allowing alternating current to pass. In analog filter networks, they smooth the output of power supplies. In resonant circuits they tune radios to particular frequencies. In electric power transmission systems, they stabilize power flow; the property of energy storage in capacitors was exploited as dynamic memory in early digital computers. In October 1745, Ewald Georg von Kleist of Pomerania, found that charge could be stored by connecting a high-voltage electrostatic generator by a wire to a volume of water in a hand-held glass jar. Von Kleist's hand and the water acted as conductors, the jar as a dielectric. Von Kleist found that touching the wire resulted in a powerful spark, much more painful than that obtained from an electrostatic machine.
The following year, the Dutch physicist Pieter van Musschenbroek invented a similar capacitor, named the Leyden jar, after the University of Leiden where he worked. He was impressed by the power of the shock he received, writing, "I would not take a second shock for the kingdom of France."Daniel Gralath was the first to combine several jars in parallel to increase the charge storage capacity. Benjamin Franklin investigated the Leyden jar and came to the conclusion that the charge was stored on the glass, not in the water as others had assumed, he adopted the term "battery", subsequently applied to clusters of electrochemical cells. Leyden jars were made by coating the inside and outside of jars with metal foil, leaving a space at the mouth to prevent arcing between the foils; the earliest unit of capacitance was the jar, equivalent to about 1.11 nanofarads. Leyden jars or more powerful devices employing flat glass plates alternating with foil conductors were used up until about 1900, when the invention of wireless created a demand for standard capacitors, the steady move to higher frequencies required capacitors with lower inductance.
More compact construction methods began to be used, such as a flexible dielectric sheet sandwiched between sheets of metal foil, rolled or folded into a small package. Early capacitors were known as condensers, a term, still used today in high power applications, such as automotive systems; the term was first used for this purpose by Alessandro Volta in 1782, with reference to the device's ability to store a higher density of electric charge than was possible with an isolated conductor. The term became deprecated because of the ambiguous meaning of steam condenser, with capacitor becoming the recommended term from 1926. Since the beginning of the study of electricity non conductive materials like glass, porcelain and mica have been used as insulators; these materials some decades were well-suited for further use as the dielectric for the first capacitors. Paper capacitors made by sandwiching a strip of impregnated paper between strips of metal, rolling the result into a cylinder were used in the late 19th century.
A simulation is an approximate imitation of the operation of a process or system. This model is a well-defined description of the simulated subject, represents its key characteristics, such as its behaviour and abstract or physical properties; the model represents the system itself. Simulation is used in many contexts, such as simulation of technology for performance optimization, safety engineering, training and video games. Computer experiments are used to study simulation models. Simulation is used with scientific modelling of natural systems or human systems to gain insight into their functioning, as in economics. Simulation can be used to show the eventual real effects of alternative conditions and courses of action. Simulation is used when the real system cannot be engaged, because it may not be accessible, or it may be dangerous or unacceptable to engage, or it is being designed but not yet built, or it may not exist. Key issues in simulation include the acquisition of valid source information about the relevant selection of key characteristics and behaviours, the use of simplifying approximations and assumptions within the simulation, fidelity and validity of the simulation outcomes.
Procedures and protocols for model verification and validation are an ongoing field of academic study, refinement and development in simulations technology or practice in the field of computer simulation. Simulations used in different fields developed independently, but 20th-century studies of systems theory and cybernetics 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; these physical objects are chosen because they are smaller or cheaper than the actual object or system. Interactive simulation is a special kind of physical simulation referred to as a human in the loop simulation, in which physical simulations include human operators, such as in a flight simulator, sailing simulator, or a driving simulator. Continuous simulation is a simulation where time evolves continuously based on numerical integration of Differential Equations.
Discrete Event Simulation is a simulation where time evolves along events that represent critical moments, while the values of the variables are not relevant between two of them or result trivial to be computed in case of necessityStochastic Simulation is a simulation where some variable or process is regulated by stochastic factors and estimated based on Monte Carlo techniques using pseudo-random numbers, so replicated runs from same boundary conditions are expected to produce different results within a specific confidence band Deterministic Simulation is a simulation where the variable is regulated by deterministic algorithms, so replicated runs from same boundary conditions produce always identical results. Hybrid Simulation corresponds to a mix between Continuous and Discrete Event Simulation and results in integrating numerically the differential equations between two sequential events to reduce the number of discontinuities Stand Alone Simulation is a Simulation running on a single workstation by itself.
Distributed Simulation is operating over distributed computers in order to guarantee access from/to different resources. Modeling & Simulation as a Service where Simulation is accessed as a Service over the web. Modeling, interoperable Simulation and Serious Games where Serious Games Approaches are integrated with Interoperable Simulation. Simulation Fidelity is used to describe the accuracy of a simulation and how it imitates the real-life counterpart. Fidelity is broadly classified as 1 of 3 categories: low and high. Specific descriptions of fidelity levels are subject to interpretation but the following generalization can be made: Low – the minimum simulation required for a system to respond to accept inputs and provide outputs Medium – responds automatically to stimuli, with limited accuracy High – nearly indistinguishable or as close as possible to the real systemHuman 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 fastest method to identify the failure cause. A computer simulation 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 investigate the behaviour of the system under study. Computer simulation has become a useful part of modeling many natural systems in physics and biology, human systems in economics and social science as well as in engineering to gain insight into the operation of those systems