What is Model: Definition and 1000 Discussions

A model is an informative representation of an object, person or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin modulus, a measure.
Representational models can be broadly divided into the concrete (e.g. physical form) and the abstract (e.g. behavioural patterns, especially as expressed in mathematical form). Of particular importance in the modern context, conceptual models are central to philosophy of science, as almost every scientific theory effectively embeds some kind of model of the physical or human sphere.
In commerce, a model might instead reference a specific version or configuration of a product offering, rather than functioning as a representation of something else.
In taxonomic settings (e.g. biology, architecture, art) a model is sometimes a particular instance of a set of related entities (species, built structures, artistic compositions) chosen as a convenient reference point around which to build discourse; such a model is almost always chosen to typify some central tendency of the group, exemplify the group's defining characteristic, or reify the group's historical lineage.
Kinds of models include:

View More On Wikipedia.org
Recent contents Top users
  1. Shriraam Prabu

    Auto track using Kinematic model

    Hi, I'm trying to implement an auto track guidance system for ground vehicles (Eg Tractors), I'm using Matlab and Simulink. I'm at a point where I can calculate heading errors. I'm not too sure how to calculate the lateral errors. Also, I need help in designing the controller. I'm using...
  2. Raptor112

    A Optical Bistability and the Jaynes-Cummings Model

    I understand that otical bistability only occurs in a specific parameter regime defined by the bimodial leaf, but I have read that bistability originates from highly non linear dynamics of the system. As we are dealing with a qubit in a cavity that is being driven so things become non-trivial...
  3. Raptor112

    A Dispersive Regime in Jaynes-Cummings Model

    From the reading I have done: In the presence of a drive, which is described by an addition term in the Jaynes-Cummings Hamiltonian, the Hamiltonian cannot be solved analytically. The dynamics of the system become non-trivial, with the behaviour depending on the specic parameter regime. So, the...
  4. B

    Blasius Model Solution in Matlab | Boundary Layer Profiles without ODE45

    Homework Statement Program, without any built in functions (like ODE45), a solution to the Blasius Equation in Matlab that outputs boundary layer profiles for given x values, u values, etc. Homework Equations 2f''' + f''f = 0 fj = fj-1 + Δη/2 * (gj + gj-1) gj = [Δη2/4][2gj+1/Δη2 + 2gj-1/Δη2 +...
  5. Samy_A

    Particle Books about the Standard Model (with math)

    I've been trying to learn more about the standard model. Leonard Susskind's lectures have been very helpful for SR, GR and QM. His lectures about the standard model are interesting, I learned a lot, no question. But he doesn't really cover in any depth the mathematical side of it. He mentions...
  6. iheadset

    B Markov model on a sequence of numbers

    Dear Sir, Assuming that my lottery machine can generate 10 numbers (0..9), in which 0 and 9 are supposed to be starting and ending states of my Markov chain. I apply Markov chain to model each number appearance because I would want to modify the random generation process into, say, my own...
  7. Telemachus

    Nearly free electron model: band gap

    I was trying to determine the bandgap in the nearly free electron model. I'm having trouble to determine the band gap bewteen the second and the third band. Its a one dimensional problem. So, the central equation reads: ##\displaystyle \left [ \frac{\hbar}{2m} (k-G)^2-E \right ]c_{k-G}+...
  8. thegirl

    Basic interactions in the Standard Model

    Hi, Is there a list of basic interactions in the standard model? Does anyone know where I can find this list of basic interactions in the standard model?
  9. P

    Geocentric vs heliocentric model evidence

    Homework Statement I wasn't sure where the most appropriate place to post this question is. But anyway. Which of these, if any, can be used as evidence that the Earth revolves around the sun. 1. The phases of the moon 2. The seasons 3. analemma of the sun 4. solar and lunar eclipses 5. the...
  10. wolram

    Is the LCDM Model Challenged by Evidence of Running Cosmic Vacuum?

    I noticed this in the arxivs, i thought the LCDM model was irifutable but it seems some are trying to better it. arXiv:1602.02103 [pdf, ps, other] First evidence of running cosmic vacuum: challenging the concordance model Joan Sola, Adria Gomez-Valent, Javier de Cruz Perez Comments: LaTeX, 6...
  11. domainwhale

    Insights High Temperature Low Temperature Duality for the Ising Model on an Infinite Regular Tree - Comments

    domainwhale submitted a new PF Insights post High Temperature Low Temperature Duality for the Ising Model on an Infinite Regular Tree Continue reading the Original PF Insights Post.
  12. C

    Attempting to model traffic flow after front car decelerates

    So I'm trying to create a very simple mathematical model for a very idealized theoretical situation of traffic flow. In this situation I'm considering vehicles to be points (no length) each going the same speed with the same distance between them. The vehicle in front (vehicle 1) slows down and...
  13. A

    Finding the state space model of a nonlinear system

    Homework Statement The state space model of a nonlinear system is x'_1(t) = 2x^2_2(t) - 50 x'_2(t) = -x_1(t) - 3x_2(t) + u(t) Where x_1(t) and x_2(t) are the states, and u(t) is the input. The output of the system is x_2(t). Find the state space model of this system linearized at the...
  14. Feeble Wonk

    Can Anyone Explain the Spin Foam Model in Simple Terms?

    Help. I'm really struggling with the general idea here. The intricacies of the theory are hopelessly beyond my cognitive reach. I'm just trying to get a general handle on the big picture concept. I read a bit where Lee Smolin referred to this model as a leading theory that characterized space...
  15. alw34

    Does this dynamic model complement the Balloon Analogy?

    This is a kind of cooperative problem solving post. But don't be too terribly 'focused' because likely I have missed important issues. I had not seen a dynamic illustration like this before: maybe I am over impressed, weak-kneed, like seeing Kate Hudson the first time?? In Wikipedia at...
  16. J

    Electrostatic analysis of cad model of protons neutrons

    Could the orbit filling order of electrons be more classical and less quantum? I attached a jpeg and need someone to do a electrostatics analysis of the CAD model version of it. Does anyone have an electrostatics software package and have time to do a finite element analysis on a 3-D part to...
  17. M

    Does the Bohr model go against classical Electromagnetism

    I was told in high school that Rutherford's atomic model was wrong because an electron which is in acceleration must release energy. That's how electromagnetic waves are made. and then I was told that Bohr gave his model and solved this problem. By making energy quantized. But what I really...
  18. jerromyjon

    Exploring the Gravity Model: The Impact of Photons on Mass and Tensor Theory

    I was in deep thought about the mass of photons (assuming they only impart "mass" as they approach a given mass) and wondered how that might work to model gravity as a continual stream of "virtual" photons. Does this sound unique or did I simply think up a way to describe tensors?
  19. C

    Calculating Forces and Angles in a Model Plane System

    Homework Statement A motorised model plane is attached to a light string anchored to a ceiling. The plane follows a circular path of radius 0∙35 m as shown in Figure 2. The plane has a mass of 0∙20 kg and moves with a constant angular velocity of 6∙0 rad s−1 . (a) Calculate the central force...
  20. tesla_sm

    How do we model metal nanoparticles for MD simulations?

    I am trying to model metal NPs capped with organic agents to simulate their phase transfer behavior from aqueous to organic. Not doing computational chemistry courses has had me to disadvantage. Would love some initiation or a jump start primer for the same. Looking forward for cues to get me...
  21. Y

    Fitting data to complicated model

    1) For standard non-linear least squares, the standard approaches are to either a) to use the jacobian to linearize, and proceed with linear regression, or to b) linearize the raw data 2) When data needs to be "fit" to a complicated model (e.g. some non-linear differential equation) that...
  22. zonde

    Efficiency model in loophole free photon Bell tests

    I would like ask comments about assumed photon detection efficiency model used in these experiments that test Bell inequalities and consequences if it does not hold. http://arxiv.org/abs/1511.03189 http://arxiv.org/abs/1511.03190 Detection efficiency is calculated as two-fold coincidence events...
  23. T

    Calculating the Z2 Invariant in Kane-Mele Model

    Hi Everyone, As part of my computational project in topological insulators, I wish to calculate the Z2 invariant in my tight binding model of Kane-Mele Graphene. I have so far produced band structure and surface states consistent with literature, and have been looking at the theory of the Z2...
  24. vabm

    Enunciation/notation in utility maximisation model

    Hi Everyone. I am working on a model that I think can be defined as a utility optimisation problem but I'm struggling with the enunciation and notation. The model should describe how the utilities of a set of agents A={1,2,...,n} increase with the availability of a larger set of product types...
  25. R

    Standard model says 17 particals, M theory says 18?

    Hi. I've only just started reading on M-theory. I'm otherwise a lay person so I'm going to have some basic questions. Here's my first. Standard Model has 17 elementary particles right? But doesn't M-theory say there's 18? Or 36 if you include the symetrical ones. So am I missing one particle...
  26. S

    Any models that can predict nuclear reactions?

    Are there any good models, software or codes that can predict the probabilities of nuclear reactions where an atom of a given type strikes another atom of another type with a given energy? Or is this information only obtainable experimentally? To further clarify, I am interested determining...
  27. A

    Geocentric model: how long was it taught in universities?

    I have a historical question which I'm not finding any reference for. I recall how my former professor of history of science told us that the geocentric model was still taught for about a century in the accademia, long after Galileo's discovery of the phases of Venus and long after the...
  28. N

    I How the standard spacetime model relates to reality

    As I understand it, the standard spacetime model is a 4-dimensional geometric object, and that my personal history is just a particular curve in the model. Reality as I experience it though is that I move through time, and thus I have the concept of the present in which "now" corresponds to the...
  29. Mr Davis 97

    AD/AS Model for economics

    Homework Statement If the AD curve intersects the AS curve in the intermediate section of the AS curve, can you calculate the increase in real output in the AD/AS model resulting from the $100 million increase in government spending? If not, what additional information would you need? Homework...
  30. S

    Standard Model, Mass in QFT - Is There Consensus?

    I realize that Wiki is not the preferred reference source here, but I'll go ahead with this question anyway... In the latest iteration of the article on the Standard Model is the statement, "We see that the mass-generating interaction is achieved by constant flipping of particle chirality." Is...
  31. Azaxa

    Transmission Line Model (TLM) End Resistance (Re)

    Hi guys. I'm looking into the modelling of a transmission line model (TLM) and feel that I'm understanding it fairly well. Although, one parameter keeps popping up with very little explanation as to what it actually is. It seems that to characterize contact resistance for a e.g. GaAs TLM with...
  32. K

    Electronic materials -using the Kronig-Penney model

    Hey guys I need your helps. Show you as pictures.
  33. Azaxa

    Transmission Line Model (TLM) End Resistance (Re)

    Hi guys. I'm looking into the modelling of a transmission line model (TLM) and feel that I'm understanding it fairly well. Although, one parameter keeps popping up with very little explanation as to what it actually is. It seems that to characterize contact resistance for a e.g. GaAs TLM with...
  34. J

    I To create a new model on physics what do i need to have?

    to create a new model on physics what do i need to have?
  35. K

    Neutrino miminal standard model vs string/M-theory

    back ground http://arxiv.org/abs/0912.0208 Asymptotic safety of gravity and the Higgs boson mass Mikhail Shaposhnikov, Christof Wetterich (Submitted on 1 Dec 2009 (v1), last revised 12 Jan 2010 (this version, v2)) There are indications that gravity is asymptotically safe. The Standard Model...
  36. V

    Linearizing a nonlinear least squares model

    I have a nonlinear least squares problem with a set of parameters \bf{g}, where I need to minimize the function: \chi^2 = \sum_i \left( y_i - M(t_i ; {\bf g}) \right)^2 The t_i are some independent parameters associated with the observations y_i and the model function has the form M(t_i ...
  37. W

    Order of calculations solar system model

    I am really, really stuck! I am trying to write java code to model the solar system, or at least currently just earth, the sun and mercury. I've made a big mistake somewhere, the planets are very unstable and either move in a line or spiral inwards! I just wanted to check that I'm doing things...
  38. Q

    Bandgaps in kronig penny model

    can someone explain to me how the bandages change in kronig penny model
  39. T

    Haldane Model: Does edge current exist for a filled band?

    Hi all, I'm currently trying to investigate the edge current on a finite strip of Zigzag Haldane model (spinless, pi/2 phase) and I measure the current (in my code) by taking the expectation value of my current operator which is a function of wavevector k, for each eigenvector of the...
  40. K

    If Sterile neutrino and axions exist, is that standard model

    it's commonly stated that the standard model has no dark matter candidate. axions and/or sterile neutrions are well motivated extensions of the standard model. if experiments show they exist and are a part of dark matter, would this still be within the framework of the standard model, or is it...
  41. Aaron young

    Reworking of the Drude model using scattering statistics

    Homework Statement The problem I have been set is to rework the Drude model using clearly defined scattering statistics. Homework Equations The Drude model as we have been given it is in terms of momentum \vec{p}(t+dt)=(1-\frac{dt}{\tau})(\vec{p}(t)-q\vec{E}(t)dt)+(\frac{dt}{\tau})(0) Where...
  42. Q

    How Accurate Are Your Kronig-Penny Model Graphs Compared to Wolfram?

    Hi I draw the graphs for kronig penny model when E>V0 and E<V0 but I am not sure about this graphs when I compare it with Wolfram is there someone can help me with it? thanks
  43. I

    Average Speed in Kinetic-Molecular model

    Hello, In the Kinetic-Molecular model for gas molecules in a container it is assumed that the square of the x-y-z velocity components is the same, how is it possible that we assume this?
  44. 22990atinesh

    Numerical Problem on Processor Pool Model

    Consider the case of a distributed computing system based on the processor-pool model that has ##P## processors in the pool. In this system, suppose a user start a computing job that involves compilation of a program consisting of ##F## source file ##(F < P)##. Assume that at this time the user...
  45. D

    Design of deoxygenating system for offshore water injection

    Any ideas on how I could model a deoxygenating system and which software would be best to use to do so. Thanks
  46. H

    Torus used to model 4D rotation

    A torus can be used to model rotations of a sphere in 4 dimensions. Such rotations have two planes of rotation at right angles to one another. So one rotation plane corresponds to rotation around the major axis of the torus, and the other rotation plane to rotation around the minor axis...
  47. Gbl911

    Compression Nozzles on Model Rockets

    I am doing a experiment with model rockets to see if a added compression nozzle on a model rocket would make the engine perform better. As you can see in this picture there is a small clay nozzle immediate to the propellant. This is the same place that you put the igniter. My experiment is...
  48. N

    Using Airy's Model of isostatic equilibrium, solve for....

    Homework Statement Using Airy's Model of isostatic equilibrium, solve for the average anti-root height due to the ocean and the average density of the upper mantle. given info: ocean depth avg = 4km ocean crust is 10 km thick avg continental crust if 40 km thick avg all crust is the same...
  49. M

    Work-kinetic energy theorem - model rocket velocity/height

    Homework Statement A student experimenting with model rockets measures the speed of a vertically-launched rocket to be 18.0 m/s when it is 75.0 m above the ground on the way up. The rocket engine fires from when the rocket is at ground level to when it is 8.75 m above the ground. If the rocket...
  50. MathematicalPhysicist

    Exploring Conjectures in a Random Matrix Model - arXiv Study

    Is any of the conjectures in: http://arxiv.org/pdf/hep-th/9610043v3.pdf have been proven/disproven? what has been left still open? I am thinking of reading this article sometime in the future, hope it's digestable (but first need to finish my studies of QFT and GR.)
Back
Top