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:
I have an assigned project in Physics with numerical modeling, to which I am supposed to use Euler's method to approximate the velocity of a "mass sliding down a frictionless in the shape of a quarter circle of radius 2.00 m."
The assignment also states: "Do three trials: t = 0.2s, t = 0.02s...
Hi everyone,
Homework Statement
I've been having a bit of trouble with my mathematics coursework. We have to model an aeroplane that has just landed with two equations. One prior to braking, one after. I've used a model with a quadratic drag approximation; and I'm not certain if my result...
Hi,
I am looking to get some good information sources on modelling nuclear power in power plants and related fields. Anyone got any good starting points ?
P.S. I am a biomedical engineer looking into different fields.
Hi, I have been reading a book regarding modelling vehicle behaviour using multi-body systems.
It discusses the use of points, vectors, local and global co-ordinate systems as well as assigning degrees of freedom to various parts. I am pretty confident with the whole concept but I am unsure...
Hi, my name is Steve..
I am working on a ducted fan. I want to simulate it in Fluent in order to optimize my design. I know that sliding mesh technique and multiple reference frame method will be used but I am having problems in Gambit.
I do not know how to model it in Gambit. I have made...
Hello all,
I am attemtping to model crystal twinning using DFT methods. In particular I wish to look at the twin energy as a function of twin angle in a hcp system. I am running into difficulty however in attempting to create my repeat unit prior to my calculations. I was wondering if...
Given a power spectral density Sn(f) (or alternatively the autocorrelation function), is there a way to output random noise in Mathematica? Not sure if anyone here will know this but it's worth a try.
Hi all,
I am currently working on a water pipeline project and am investigating a pipe burst scenario at a pump station with the aim of producing a flow rate entering the pump room in the event of a burst.
For simplification and what has been used previously on similar jobs is to model...
Hi,
I am just finished my Calc II class and a programming class and I am trying to write a computer graphics shader...
My goal is to model this scenario:
"Imagine a brick wall standing on a plane --- a shadow will be cast depending on the light source" ---my goal is to model the dispersion of...
How is it best to model Helium gas,
Ideal gas equation?
Dieterici?
Van der Waals?
some other equation?
Also if it is dieterici or van der waals,what the values of a and b, the constants in the equation of state.
i need help in modeling magnetic field which will be created using arrangement of magnets which may be in motion ,, i want a simulation model or some software for this please suggest some... thanks
Hi guys,
Im a newbie to this site... I have been wrking on a simulink model of a F1 car for a few days.I wanted to simulate the start of a F1 car from standstill.. I used the following basic concepts:
1) The engine is revved at say around 11000 .rpm
2)So when the lights go off, I engage the...
Help in mathematical modelling phase diagrams! :(
Mathematical modelling question on predator-prey models
logistic prey-predator model with prey logistic growth
dx/dt= ax - bx^2 -cy
dy/dt= -ey + fxy
ax = growth rate of prey in the absence of predation
-cxy = the death rate per...
logistic prey-predator model with prey logistic growth
dx/dt= ax - bx^2 -cy
dy/dt= -ey + fxy
ax = growth rate of prey in the absence of predation
-cxy = the death rate per encounter due to predation
-cy = the natural death rate of predators in the absence of prey
fxy = is the prey's...
Let us assume a dynamic system which has vector with 'n' components (which are non-negative integers from 1->n) at time t=1. In other words we have a permutation over 1->n at time t=1. Assuming time to be discrete, at any time time 't' , the system evolves such that there are 't' permutations...
Hi,
I am looking for some guidance w.r.t modelling real world phenomena using ODE/PDE/SDE type equations. Are there books which go into the issues of modelling real world phenomena with these sorts of equations?
Thanks in advance,
Excor.
Homework Statement
Prepare the Relational Tables to represent the following situation, which is
described by means of text and an Entity Relationship Diagram.
Note: Do not attempt to modify the ERD. Your task is to state the relational tables
which fit the given ERD.
The NSW government...
Hi,
I am trying to calculate the power of a reflected electromagnetic field and can't find a physical explanation for a given solution.
I've noticed the following example:
The Plane has a radar for altitude measurement which emmits the power Ptx at the frequency ftx. Calculate the power...
when modelling a function for a Fourier series, what determines which function i select from the forcing function for an and bn?
eg
in the following would 1-t^2 be used in the an or bn formula?
http://users.on.net/~rohanlal/fourier2.jpg
Hello all.
I'm modelling several new aircraft as mods for a flight sim.
These mods are all WW2 birds like the Kittyhawk and Ta152.
The generic computer models have a series of terms I am unsure about. So far I've been using existing aircraft modelling as a guideline but as we are expanding...
Homework Statement
Hi all,
I'll outline the situation first, then I'll ask about what I need.
Tank (designed by me / other students) which has no closed in top or bottom. Can be any shape, i.e. cylinder / cone / square etc etc. Made from cardboard with plastic bag in the middle acting...
Hi, I am trying to simulate condensation of water in air.
I am using the shan-chen multi-phase multi-component model in order to achieve this (a variation of the Lattice Boltzmann Equation, not too important). The goal ultimately is to study the effect of condensation in fuel cell membranes...
Hi PF,I'm working on a semi-classical model for a group of rather strange polymers based on carbon, nitrogen, and oxygen. In this treatment, I'm approximating the bond length and bond angle to be more or less classical (ie. ball and stick). But I would also like to treat the dihedral angles...
Hello All. I am a second year engineering student switching over from Mechatronics engineering to physics with a minor in computer sciences. While I have done some programming in C, C++, Java, TCL and Assembler, I would like to know how I would approach modeling physical phenomena...e.g basic...
Homework Statement
"The very simple population model for a resource limited population with constant immigration, and no breeding, M'(t) = M(S-M) + I attempts to describe the growth of corals on a reef. Function M(t) represents the biomass of corals."
a - Explain which term gives the...
Homework Statement
I have 3 pairs of resistors and capacitors, with each pair in parallel. These pairs are in series with another resistor and a voltage source. I have been asked to find the voltage across the resistor in the middle pair as a function of time, assuming that at time t=0 the...
Hello! I chose an aspect of a dynamical system exhibiting resonance to model. The focus of the project is on the resonant response of the system.
If the wind has a frequency that matches the natural frequency of a turbine, then the turbine will resonate due to wind. I am working on modelling...
This post simply represents a learning process, my own. As such, it is only attempting to understand how the energy density might have changed with time and what can be inferred from this. There are 3 diagrams attached to this post, figure-1 is an attempt to show the relative density of matter...
Homework Statement
I need to model the streamlines for an incompressible, irrotational flow about various symmetric bodies, starting with an ellipseHomework Equations
for a uniform flow in the positive x direction, psi =y
for a source/sink of strength K at (xn,yn)
psi = Karctan((y-yn)/(x-xn))...
Can anyone help clarify a few things about telling the time series model used based on the (partial) autocorrelation graphs. For example, if I have to difference a series once to get the autocorrelation and partial correlation graph completely within the confidence bands, does that mean it's...
Modelling "Gravitational" Motion
Hi All,
I am new here and this is not a homework question... I'm turning 40 this year and my retention of physics is low to say the least. I am trying to rekindle some knowledge... Just for fun!
I am trying to use a spreadsheet to model the motion of a...
so I am tearing my hair out with this one...
the density of the Earth's atmostsphere vaires with height r above the Earth's surface as
p = p(o) exp(-r/r(o))
where p(o) the density of the air at ground level, is 1.3 kg/m^3 and r(o) the scale height is 8km
use this to estimate an...
Okay, I'm doing my yr 11 Mathematics assignemnt and I need help.
How do you find a Logistic or Polynomial function/equation using data? (in steps please!)
I could just give some example data as... an example, but I think I'll just throw 1 small section of my assignment, use the data or...
I don't understand how muscles create torque. More specifically, I am trying to model muscles inside a computer program. I have two line segments (bones) from A->B and B->C, so B is obviously the joint. I was thinking of modeling a muscle as a spring going from A to somewhere on the line BC (but...
Sorry for such an easy question LOL..
So.. I need a bit of help,
I was thinking of modelling a ram air intake on a car.
But it seems like I'm not educated enough..
What I know is:
the car goes with 100 km/h speed,
the engine consumes 1800 liters of air / minute,
and the intake at...
I need a book to study the theory for turbulent modeling for external flow. So far I used Fox & McDonald for fluid dynamics, it has turbulent modeling for pipe flow. I learned to simulate it in fluent & learned a lot more in its tutorials(though i didn't know the theory part:biggrin::redface:)...
Could someone please help me urgently?
The problem is: 130 micrograms of thyroxine is needed in her bloodstream. Her doctor prescribed one 100 microgram ,thyroxine tablet to be taken every day. If the half-time of thyroxine is 6.7 days, either justify that the uptake of thyroxine by the body...
I'm having a bit of trouble working out the cosine function for the data I have on tide charts.
Homework Statement
I need to put the data provided into the cosine function y=acos(nx-b)+c
Morning average high tide: 5.137 metres
Morning average low tide: 1.29 metres
Afternoon average high...
I am aware of the very valuable analysis skills physics teaches. A physics major may not be possible for me so with your experience with physics or electrical engineering, would you say you learn how to model physical systems better with electrical engineering or with mechanical engineering? It...
hey everyone,
this is for a school project, I'm wondering what would be the best for building a model to represent the Earth's magnetic field. it has to be 3D so what would be the best way to represent this? Also it has to do a demonstration what would be a good way of demonstrating the Earth's...
Hi everybody. This is my first post in this forum. I am working with COMSOL MULTIPHYSICS and I am trying to model a laboratory burner (Meker burner) heating a copper disc placed above the burner. I am modelling the burner as a boundary setting of heat flux entering the domain. I have obtained a...
Homework Statement
A particle of mass m moves along the positive x-axis with a potential energy given by
V(x)=C+4/x^2+x^2
where C is a postive constant.
Calulate the equilibrium position X0 of the particle.
Homework Equations
None.
The Attempt at a Solution
I realize...
Homework Statement
I need some help with all of the questions in the attatchment but would love it if you could provide some help with the first question please.
Homework Equations
In the file.
The Attempt at a Solution
Dont be silly, I don't have a clue. If I could do it I...
Hi all!
OK, hopefully this will be a very quick question. Basically, I want to know how to model a vacuum tube (both triode and pentode) in terms of creating a dynamic system model. For example, if were to look at the voltage in an inductor as a function of time, I would employ the relation...
OK, I have an assessment task to create a 3D model of SOME of Einstein's thought experiments involving trains and mirrors, and present it to the class. Therefore a minimum of 2 thought experiments. The task is unique (ie each student is required to model a different part of the course), and I'm...
University project which involves modelling the acceleration of a car from 0-60mph given certain variables. I am looking for help with how torque and power relate to the driving force of the car, I think i have every thing else covered but any help will be greatfully recieved. The model will be...
Hello My friends , I want to deal with a nozzle in an unsteady flow , what methodology should I use in your opinion to solve it using Computational Fluid Dynamics and using Fluent software .
Thanks in advance
Due to complications I have with drawing and uploading pics at the moment, I'll simply describe the model instead of posting a pic; it's a cantilever beam (ignore the cross section and modulus of elasticity given in the pic, and the force P) of length L = 1, the coordinate axis x is along the...