Finite Definition and 1000 Threads

Deaar all good morning I am very interested to the flux in a slab of extrapolated thickness a, containing distributed sources of neutron. A I have an example in which the source is given as s(x)=S(x+a/2) where S is a constant and x distance from the center of the slab. You mentioned in one...

It's been said that the universe has no edge, it's expanding, it has no center and the big bang was the birth of energy, matters and space-time. I also often hear that it's been estimated the universe has approximately 200 billion galaxies or more or much more. Also the number of particles...

Hi. I'm reading "Quantum Field Theory - Mandl and Shaw" about how to derive the cross-section and in the derivation the authors make the following argument "For large values of T and V, we can then take \delta_{TV}(\sum p_f' - \sum p_i) = (2\pi)^4 \delta^{(4)}(\sum p'_f - \sum p_i) and...

Hi All, I'd like to what kind of steps need to be taken to accurately estimate the yield lines of RC structures. My intention is, to know what type of loading is acting on beams transferred from slabs. I know how to formulate thin/thick plates and shells. The results converges with commercial...

Let G be a finite group. Under what circumstances ... Homework Statement ... is that map δ:G→G defined by δ(x)=x2 an automorphism of F. Homework Equations And automorphism δ:G→G is a bijective homomorphism. The Attempt at a Solution The only circumstance I've so far found is...

Folks, The element equations for a uniform bar element with constant EA according to the attachment is given as ##\displaystyle \frac{E_a A_e}{h_e}\begin{bmatrix} 1 &0 &-1 &0 \\0 &0 &0 &0 \\-1 &0 &1 &0 \\ 0 &0 &0 &0 \end{bmatrix}\begin{Bmatrix} u^e_1\\v^e_1 \\u^e_2...

Homework Statement Evaluate \int_{R} \int \frac{xy^2}{(4x^2 + y^2)^2} dA where R is the finite region enclosed by y = x^2\,\,\text{and}\,\, y = 2x The Attempt at a Solution I think the easiest way to integrate is to first do it wrt x and then wrt y, i.e \int_{0}^{4}...

I'm reading about automata theory and am currently at the part about what a FSA can recognize and what it cannot. They use the example of some language: {0n1n | n ≥ 0} which an FSA cannot be built for. When I first started learning about state machines before reading into theory of...

Homework Statement So basically, I'm studying the proof for this: "In a finite dimensional vector space, the length of every linearly independent list of vectors is less than or equal to the length of every spanning list of vectors." What the book (Axler's Linear Algebra Done Right 2e) does...

Homework Statement prove by induction that if A and B are finite sets, A with n elements and B with m elements, then AxB has mn elements Homework Equations AxB is the Cartesian product. AxB={(a,b) such that a is an element of A and b is an element of B} The Attempt at a Solution...

Well I am coming across problems like finding permutation of some n characters. On paper I can find all the permutations given some finite characters easily but when it comes to programming it is hard, why? Why is it hard to tell a computer what I myself can do it so easily? This is strange -...

Homework Statement Solve the energy eigenvalue problem for the finite square well without using the symmetry assumption and show that the energy eigenstates must be either even or odd. Homework Equations The finite well goes-a to a and has a potential V0 outside the box and a potential...

A solenoid of length 0.4 m and diameter 0.6 m consists of a single layer of 1000 turns of fine wire carrying a current of 5 x 10-3 A. Calculate the magnetic field strength on the axis at the middle and at the ends of the solenoid. I know the field inside a long solenoid, B = μNI, which is...

Folks, I have the book An Introduction to the Finite Element Method by J.N Reddy. The following website provides http://highered.mcgraw-hill.com/sites/0072466855/student_view0/executables.html access to the Fortran Executable but I am not sure how to work them. I am just beginning to...

Prove that a nonempty finite S\,\subseteq\,\mathbb{R} contains its Supremum. If S is a finite subset of ℝ less than or equal to ℝ, then ∃ a value "t" belonging to S such that t ≥ s where s ∈ S. This is the only way I see to prove it, I hope your help :)) Regards

Homework Statement Let A be an integral domain with field of fractions K, and suppose that f\in A is non zero and not a unit. Prove that A[\frac{1}{f}] is not a finite A-module. [Hint: if it has a finite set of generators then prove that 1,f^{-1},f^{-2},...,f^{-k} is a set of generators for...

A pattern that does not continually re-occur?

The spectrum of the Cosmic Microwave Background radiation - the flash of the Big Bang, aligns almost precisely with the shape of the Black Body radiation curve. This means that the CMB radiation came from a state that was in thermal equilibrium. Since thermal equilibrium is a state of maximum...

E=MC2, if I understand it correctly, tells us that an object would need an infinite amount of energy and mass in order to travel at light speed, which is why particle accelerators can only travel at 99.99999 or so percent of the speed of light. With this in mind I have a couple of questions...

Homework Statement Prove that every Hausdorff topology on a finite set is discrete. I'm trying to understand a proof of this, but it's throwing me off--here's why: Homework Equations To be Hausdorff means for any two distinct points, there exists disjoint neighborhoods for those points...

what is an infinite group that has exactly two elements with order 4? i let G be an infinite group for all R_5 ( multiplication modulo 5) within this interval [1,7) so i got |2|=|3|=4. i'm not sure this is the right answer but i couldn't think of anything else at a moment. help please.

Folks, Is there anyone out there familiar with 'An introduction to the Finite Element Method' by J.N. Reddy? I am struggling to decipher what is happening on page 129 as shown in the attachment. If some-one is willing to help I will reply with a more specific query on that page. Thanks

Hi, I have a question regarding finite difference approximation: Consider the finite difference approximation u'(xj-1/2) + λu(xj−1/2) ≈ 1/h*[u(xj ) − u(xj−1)] + λ(θu(xj ) + (1 − θ)u(xj−1)) how can I Find the order of approximation as a function of θ? I am really new in this field, so...

Hello, I know the value of a field variable in a 3d mapped finite element mesh. Can anyone suggest an effective method/methods to find its gradient throughout the mesh.

Homework Statement I've read in my textbook, and confirmed via WolframAlpha that lim x->0 (cosx/x^0) =1 , and need an explanation for it. I thought it should be ∞ or something undefined, since 0^0 is undefined. Homework Equations The Attempt at a Solution I tried to use L'Hospitale on the...

Homework Statement I've come across the type of sum in several places/problems but seem to be making no progress in trying to simplifying it further. We have a finite series of some exponential function. \sum_{n=0}^{N}e^{-na} Where a is some constant, a quantum of energy or a...

Homework Statement Please see the attached photo. (The one with the green highlighter), I haven't written it out to avoid mistakes. Homework Equations None. The Attempt at a Solution I have constructed a moore state diagram, a state transition table and come up with boolean...

http://books.google.rs/books?id=vrcHC9XoHbsC&pg=PA252&lpg=PA252&dq=Nolting+Finite+Ising+lattice&source=bl&ots=5uRHp0iALf&sig=_YBUSvbCBbhNQJ5Zu1go9AsEkM8&hl=sr&sa=X&ei=y_E4UIEyyobiBPvFgMgM&ved=0CC0Q6AEwAA#v=onepage&q=Nolting%20Finite%20Ising%20lattice&f=false A finite lattice X with so...

Various closed form formulas for summing the first n terms of a sequence \{a_i\} of numbers can be developed by considering the various order differences of the terms, such as {\triangle} a_i = a_{i+1} - a_i and \triangle^2 a_i = \triangle ( \triangle a_i) . Closed form formulas occur if...

My question is about the shaded area in the attachment? How did the author get that all the elements of order p or 4 of L are contained in K? I mentioned the abstract but I do not think there is a need for that. Help?

Homework Statement the first two energy eigenstates of a 1 nm wide finite well of barrier height 8vo have energy eigen values of 0.66ε and 2.6ε. calculate the expectation value of a linear superposition of these states? Homework Equations airy equations The Attempt at a Solution...

Homework Statement Consider the finite length x[n]= 2δ[n]+δ[n-1]+δ[n-3] We perform the following operation on this sequence: (i) We compute the 5-point DFT X[k] (ii) We compute a 5-point inverse DFT of Y[k]=X[k]2 a) Determine the sequence y[n] for n= 0, 1, 2, 3, 4 b) If N-point...

Homework Statement Statement: A set F can never be equivalent to its proper subset E This statement appears in Halmos's Naive set theory in the chapter 13. Arithmatic. He arrives at this statement through the following steps 0. In the previous chapter, he proves the recusrsion theorem...

I have a project where I need to solve T''(x) = bT^4 ; 0<=x<=1 T(0) = 1 T'(1) = 0 using finite differences to generate a system of equations in Matlab and solve the system to find the solution So far I have: (using centred 2nd degree finite difference) T''(x) = (T(x+h) - 2T(x) +...

Hallo, I tried to use 'finite difference' method to solve a Initial Value Problem(IVP). For the two boundaries I used periodical condtion and for the differential operators I used 4th degree center approximations. But as result, I got this thing. Where comes this strange oscillation What do you...

I am having trouble understanding the permutations of a finite set in general. I want to know what it may be used for, and how to solve some of its problems (examples?). In my attachment, I post some pictures of what I am currently reading, and what has confused me.

I was thinking about the following thing: we know that if the Lagrangian in field theory doesn't depend on the spacetime position, the Noether's theorem says that the stress-energy tensor is conserved, and that T^00 is the energy density at spacetime point x. Then if one integrates this h(x)...

Hello, I would love some help on calculating the following sum for \alpha, \beta \in \mathbb{N} and n \in \mathbb{N} \backslash \{0\}: \displaystyle\sum_{i=1}^{n-1}i^{\alpha}(n-i)^{\beta}. Thanks in advance, Latrace

Hi, I'm facing a real-life problem and I don't what specific mathematics topic it's related to. Homework Statement I know the value of the components of a vector field in three points of space and I have to find the flux of this vector field through the surface defined by those...

Homework Statement If G is a finite abelian group, and x is an element of maximal order, then <x> is a direct summand of G. Homework Equations The Attempt at a Solution I claim that the hypothesis implies that A = G\<x> \bigcup {e} is a subgroup of G. If so, then since G = < <x> \bigcup A>...

I came across this series by recognizing a pattern while trying to evaluate an integral. I was wondering if the series could be solved in a generalized form where n can vary, and if so, can the limit then be taken as n approaches infinity? You can't take the infinite series without first...

Homework Statement I'm doing a class on Numerical Solutions of DE and I have my first assignment. The problem is stated: Consider the following second order boundary value problem: \epsilon \frac{d^{2}y}{dx^{2}} + \frac{1}{2+x-x^{2}} \frac{dy}{dx}-\frac{2}{1+x}y = 4sin(3x), y(0) = 2, y(2) =...

Hii everyone, I have a sequence {ai,1<= i <=k} where i know the sum of this sequence(say x). I want to know the sum of another sequence {bi, 1<=i <=k}(at least a tight upper bound) where bi=ai*(1/2^i). Or in other words, if you know the sum of the ratio sequence and sum of 1 sequence, how to...

I know that this is a lot, but I would love some help. My trouble is at the end of Part II. Theorem (Cauchy’s Theorem): Let G be a finite group, and let p be a prime divisor of the order of G, then G has element of order p. Proof: Suppose G is a finite group. Let the order of G be k. Let p...

Proposition: If every element of G/H has finite order, and every element of H has finite order, then every element of G has finite order. Proof: Let G be a group with normal subgroup H. Suppose that every element of G/H has finite order and that every element of H has finite order. We wish to...

Hello to everyone, I would like to ask what does it mean that a theory is NOT finitely axiomatizable? What are the pleasant and unpleasant consequences of that?

Suppose I have a C∞ function, which I wish to prove attains its maximum/minimum. First I must prove that the function is bounded at all. If I determine R, the region (of the plane in this case) where the function is strictly positive, and integrate over R to find a finite answer, can I say the...

Hi all. I would like to do a finite element simulation of a coil in a time-varying magnetic field, to see how much current is induced in the coil, and also to see how the coil itself affects its surroundings. Now my question is, how do I model a coil with several thousand turns in a practical...

Just wondering, is there a way to sort of "collapse" a finite series (to get the sum) that isn't classified as arithmetic, geometric or a p-series.

Let's say we have an object. And we then say that E = (1/2)mv2. so we solve for velocity and say that v = (2E/m)^(1/2) then integrate both sides with respect to time ∫(2E/m)^(1/2)dt= ∫v dt so we then have (2E/m)^(1/2)t = distance so if time was infinitely large (long) could an...