Modeling Definition and 609 Threads

OKAY I have a trg test make up and due tomroow and I have no clue what I am doing, I've searched online chatrooms and they all want money. so this is basiaclly my last hope the test is over rATIONAL ROOTS ZEROS POLYNOMIALS ETC. please show all work if answering QUESTIONS i NEED HELP ON BELOW...

Hi there, I have been thinking about how to actually describe a system input filter consisting of several caps and an inductance in the state-space representation. The topology follows: a DC source to inductor to two parallel caps that are referenced to the same potential as the voltage...

I am trying to approximate the field of a permanent neodymium magnet as that of a magnet dipole. The magnet in link the below can be modeled by a magnetic dipole of what strength? http://www.magnet4less.com/product_info.php?cPath=11&products_id=123 Thanks in advance!

Okay so after tearing my face off trying to find a 2-cycle, I've managed to make significant process. I divided an enormous polynomial with another polynomial and got a god awful mess which incidentally was correct. Now I'm having trouble solving this equation with x in terms of c...

This question deals with a 1-parameter equation: fc(x)= (4/x)+(x/2)-c for 0≤c≤ 2.3 a.) Use algebra to find the positive fixed point p(c) of fc(x) (in terms of c) and identify its exact interval of existence a.) Ok so for the fixed point I got p(c)= -c+√(c2+8) I'm not sure if this is...

I just was wondering if anyone here has pursued a degree in scientific computing / high performance computing / computational simulation and modeling, type of degree. For example Georgia Tech's Computational Science and Engineering degree or Computational and Mathematical Engineering degree, or...

I do not if it is the right section, however hello I'm Antonio and I am Italian so I apologize for my English. I have a problem I'm trying to manage a mathematical modeling from a graphical point of view, (I applied chaos theory and the theory of earthquakes and using the concept of point...

curious as to the proper way to model this. beam is symmetric so centroid is in the middle (used to calculate distance from centroid d in bending moment of inertia equation) bending moment of inertia is I =\sum(I + Ad2) I=\frac{1}{12}bh b=base h=height d=distance of the area's...

Hi All, I'm working in OpenSCAD to draw up a 3D model of a pan flute that I could print out using a 3D printer and (with any luck!) play right there on the spot. I've looked up some of the formulas for determining the pitch of a open ended tube but I have some questions... Wikipedia says that...

[b]1. I'm carrying out the modeling of control valve using Physical method as part of my project. The first step is to get the physical model representation of a valve and then carry out the modeling. Secondly, I need to incorporate friction in the modeling to see the effect. I've seen a number...

Hi guys, just embarking on the journey of modeling with differential equations and solving them. I have a more conceptual quesiton. Linear differential equations in my book are defined to be ones where F(t, y, y', y'',...,yn) = 0 is a linear function of the dependent var y and all of its...

This a plankton herbivore model. The dimensionalized model is $\displaystyle \frac{dP}{dt} = rP\left[(K-P)-\frac{BH}{C+P}\right], \quad \frac{dH}{dt} = DH\left[\frac{P}{C+P} - AH\right] $ where $r$, $K$, $A$, $B$, $C$, and $H$ are positive constants. The dimensions of K, P, B, H, C have to...

Can anyone refer me to an introductory text about math modeling of mortgage backed securities?

http://www.openvsp.org/

Hi, I am trying to model electrical equivalent of a coaxial cable. The data I have is 1. Conductor resistance 2. Insulator resistance 3. Partial discharge 4. Insulation Thickness 5. Overall diameter Actually I planned to use an equivalent circuit that has series connection of...

Hi, I'm an online poker player and i need some help modeling a promotion that the site where i play offers. I think it's rigged and intend to prove it but I'm short on skillz. The promotion is described here and i already made a model but can't solve it. It goes like this: Supose you have...

I am trying to make simulation of severe accidents in advanced nuclear reactors. Can anybody advice me in how to write the input deck? Is there any training materials about that? Please, share your experience in simulationg nuclear reactors, problems you faced, etc.

So I've been having a bit of fun with FFT's of some nonlinear functions applied to sine waves and I noticed 'reflection' of the harmonics due to generation of frequencies beyond the Nyquist frequency. This comes as no surprise, but it left me wondering how one might model nonlinear systems...

I am trying to determine how to accurately model an open system which includes: A tank: Volume = 1320 gallons An exit pipe from tank: Diameter = 3 inches The tank is compressed from atmospheric conditions to a final pressure of 100 psig. Then the tank is allowed to decompress by opening a...

Musical-recording age Since the dawn of the musical-recording age, the preferred method of recording guitars has been to set up microphones in front of amplifiers and capture the sounds produced. This carried the limitations of eliminating the electromagnetic signal bleed from the amplifier...

Is there any website that already has 3-D models of steam generators, turbines, reactor vessels, cooling towers, or containment vessels? I am trying to develop some models so that I can rapid prototype scale model nuclear power plant components. The reactor will hold water and will be pumped...

I've been having some trouble modeling shot noise for a photomultiplier tube on Mathematica - I know that I have to use a random number generator and the Poisson distribution to do it, but I'm having trouble synthesizing everything. (There are many things I'm going to leave just as parameters...

Hi guys, I'm doing some thinking about random walk. Imagine there is a bounded 2D plane and a single spawn point. The spawn produces units which must bring in minerals scattered around the spawn. The locations of minerals are not known, so the units diffuse randomly away from the spawn...

Homework Statement I am trying to come up with a logical explanation (using an example from real life modeled in Combination and/or Permutation) to show that 3^n = summation (from i=0 to n) of (n choose i)*(2^i). In other words, I am trying to pose a combinatorial/selection/combination...

Homework Statement I am trying to come up with a logical explanation (using an example from real life modeled in Combination and/or Permutation) to show that 3^n = summation (from i=0 to n) of (n choose i)*(2^i). In other words, I am trying to pose a combinatorial/selection/combination...

Hello all, I am trying to come up with a logical explanation (using an example from real life modeled in Combination and/or Permutation) to show that 3^n = summation (from i=0 to n) of (n choose i)*(2^i). My trial is that 3^n could be modeled as having 3 boxes and we are placing n items in...

Hello, I keep myself busy by trying to model/predict standing waves in the optical path of a heterodyne spectrometer we built in our lab. We split and combine the local oscillator and the sky (it's for astronomy) with a beam splitter. Our beam splitters are wire grid polarizers. The...

I recently noticed that in Silvaco Atlas (device modeling software), the default bandgap of silicon is given as 1.08 eV. This is at 300 K, no bandgap narrowing, and no other secondary effects - it is default. However, most (all?) of the modern references (e.g. Sze, Streetman, Pierret) give the...

I am currently a double major in biology and math, interested in mathematical modeling of ecosystems and physiological systems. The math portion involves modeling and pure math, but there isn't a lot of concentration on knowing physical laws. I'm not sure if I would miss all the knowledge...

When I try and model a curve using a sine regression with my graphic calculator, it returns an error message that says: Singular Matrix I decided then to do it by hand. Here are three points. Minimum: (0,554.8), Maximum: (45, 1220.5) and a random point (20, 830.7) I want something in...

Hi All, Just wanted to know, what is a good way to learn mathematical modeling? I'm a social scientist working with simulation and data, and would like approach the issue more formally. Before trying modeling textbooks, what should I know beyond calculus? Any suggestions (books, tutorials...

Hey as part of my Physics undergrad in second year I have to take a module in either Mathematical Modelling or Linear Algebra (both course descriptions below) In first year I preferred Linear Algebra ( a very basic intro course) but apparently in second year its just all proof and no...

Hi I'm trying to preform a simple model of a ferromagnetic bar which has a coil wrapped around it. The bar has a 4×4 cm base and is 15 cm tall, the coil has an inside radius of 29 mm and outside radius 30 mm and a height of 10 cm. The goal is to find the eddy currents in the bar, generated...

This is not a homework question or anything assigned, but I would like some practice / assistance with modeling as we have not covered that in my DE class. Homework Statement The rhinoceros is now extremely rare. Suppose enough game preserve land is set aside so that there is sufficient...

I'm not sure if this should go in this section or the learning materials section, so please feel free to move this thread to the appropriate location. This semester I am taking differential equations. I have a totally awesome professor :) So far we have been working on linear algebra and...

Hi, I have a small project coming up, based around modeling (and perhaps building) a small Micro UAV system. Its a small device with contra-rotating blades (for stability), and I want to perhaps model the control system using simulink but I really don't know where to start! The aim is for the...

Hi, I'm a physics major working an internship for an engineering company at present. I have been trying to model the energy consumption and/or power for an elevator system. The goal is to be able to input different variables (cab weight, capacity, counterweight percentages, motor types...

How do I model a breadboard in simulator. The capacitance, inductance. For example, if I place a DIP part on breadboard, how much capacitance should I add between the pins in the model? I think the typical capacitance is 2pf for adjacent pins. What about pins that are 3 pins apart?

Hi all, I am currently working on a task which requires a decent model of evaporation rates from a pond. Water is deposited into the pond from a series of nozzles that spray droplets into the air over the pond. I have found some equations that I would like to use that model evaporation rates...

To the EE Forum, I am a new guy on this Physics Forum and this is my first post. I have downloaded a free software code, Finite Element Method Magnetics (FEMM) solver (see http://www.femm.info/wiki/Download) but it doesn’t work because FEMM is limited to solving low frequency electromagnetic...

I just had a weird thought. One qubit is a 2-d complex vector space which is isomorphic to a 4-d real vector space. Why can't we model the 4-manifold of space-time universe using one qubit?

Homework Statement Suppose the rate at which the volume in a tank decreases is proportional to the square root of the volume present. The tank initially contains 25 gallons, but has 20.25 gallons after 3 minutes. Solve for the general solution (do not solve for V). The Attempt at a...

My system is a compound pendulum hinged at some distance from one end and have a propeller mounted dc motor at the other end. I wish to position the pendulum with the help of motor propeller system. I tried but i am unable to get a mathematical model for it. I am getting a non linear model...

I am trying to model the diffusion of fluorophores in a cell with a source in the middle by solving the appropriate differential equation. I can solve the PDE easily enough, however as I haven't done DE's in a while, I need a refresher on how to apply the appropriate boundary conditions for my...

Hi, I would like to model static buildup and discharge. It will be appreciated if someone can point to me a direction. Thanks! Pei-Ying

Homework Statement Model the following reaction with any software. You have a gas phase reaction going on at the wall of a catalytic reactor. Homework Equations dA/dx = f1(x)*(A-B) dC/dx = f2(x)*(C-D) f1(x)*(A-B) = Const1*(D/1+D)*B f2(x)*(C-D) = Const2*(D/1+D)*B The Attempt at a Solution i...

Modeling with exponential and logarithmic functions help? Homework Statement Use Newton's Lay of Cooling, T = C + (T0 - C)e-kt, to solve this exercise. At 9:00 A.M., a coroner arrived at the home of a person who had died during the night. The temperature of the room was 70 degrees F, and at...

Hello PF, I've been given the daunting task of performing energy minimization calculations for my undergraduate research assignment. Is there someone with experience using TINKER? I wanted to use the dynamics.exe for calculations of a protein peptide sequence and it's asking me to enter a...

Homework Statement a) What can you say about a solution of the equation y' = -y^2 just by looking at the differential equation? b) Verify that all members of the family y = 1/(x + C) are solutions of the equation in part (a) c) Can you think of a solution of the differential equation y' =...

***Ugh, I'm so sorry. I think I put this in the wrong thread. It probably should be in Calculus and Beyond... I tried to delete it but didn't see that option.So my professor gave us this problem to work on but no one could figure it out. I don't know where to even start and there's nothing at...