In mathematical optimization, the Karush–Kuhn–Tucker (KKT) conditions, also known as the Kuhn–Tucker conditions, are first derivative tests (sometimes called first-order necessary conditions) for a solution in nonlinear programming to be optimal, provided that some regularity conditions are satisfied.
Allowing inequality constraints, the KKT approach to nonlinear programming generalizes the method of Lagrange multipliers, which allows only equality constraints. Similar to the Lagrange approach, the constrained maximization (minimization) problem is rewritten as a Lagrange function whose optimal point is a saddle point, i.e. a global maximum (minimum) over the domain of the choice variables and a global minimum (maximum) over the multipliers, which is why the Karush–Kuhn–Tucker theorem is sometimes referred to as the saddle-point theorem.The KKT conditions were originally named after Harold W. Kuhn and Albert W. Tucker, who first published the conditions in 1951. Later scholars discovered that the necessary conditions for this problem had been stated by William Karush in his master's thesis in 1939.
Homework Statement
A sphere under uniform rotation R, in a simple shear flow, given at infinity by
ui = G(x2 + c)deltai1
The centre of sphere is fixed at x2
Boundary conditions are ui = EijkRjxk on sphere,
and ui = G(x2 + c) at...
Homework Statement
Find the solution of the equation
v''- 4v'+5v=0,such that v=-1 and v'=1 when x=pi=3.14159Homework Equations
...
The Attempt at a Solution
I treat it as a polynomial=>r^2+4r+5=0
=>delta=-4=>r1=2+2i and r2=2-2i
v=e^[x+2](A*cos[2]+B*i*sin[2])
v=-1=e^[pi+2](A*cos[2]+B*i*sin[2])...
Boundary conditions & time domain electromagnetic waves: does classical model fit?
Consider two propagating media: a lossy dielectric medium and a lossless dielectric medium. Thus, the interface that separates them has two tangential components of electric field, one for each medium. One of...
I don't seem to grasp the meaning of boundary conditions for Laplace's equation.
Consider the Lagendre expansion of the potential at x due to a unit charge 1/|x-x'|, where x' is the position of the unit point charge.
To do the expansion, we need to consider a volume in space where the...
What is the mechanism that results in formic acid quickly converting to CO2. I know this happens under basic conditions so I'm assuming the first step is forming the formate ion.
When solving Schrodinger's eqn for a quantum ring, what would be the boundary conditions?
The solution (polar) should be
Ψ(Φ) = A exp(ikΦ) + B exp(-ikΦ)
And I believe the boundary conditions are
Ψ(0) = Ψ(2pi)
Ψ(0) = A + B
Ψ(2pi) = A exp(ik*2π) + B exp(ik*2π)
and I suppose I can...
Hi Everyone,
Apologies if this is posted in the wrong place.
I am trying to produce numerical solutions for the following initial value partial differential equations, namely the overdamped Schmoluchowski equation
\frac{\partial p(x,t)}{\partial t}=-\frac{\partial}{\partial...
If a PDE has no boundary conditions specified, how does one go about providing a solution--even if this is a general solution?
I'm stuck looking at the separation of variables and other methods which all seem to heavily rely on those boundary conditions and initial conditions.
If anyone...
Hi,
Sean Carroll talks about energy conditions in ch4 of his GR book. From what I understand we want to impose co-ordinate invariant restrictions so we need to form a scalar from the energy momentum tensor, which is done by just arbitrarily contracting with timelike/null vectors (why not...
Hello, everybody!
During the whole of my undergraduate study of physics, this one thing always bothered me. It concerns the interplay of conserved quantities, symmetries, Noether's theorem and initial conditions.
For a system of N degrees of freedom, governed by the usual Newton's laws...
Homework Statement
Find v(t) across a cap. in a series rlc circuit with no driving force (initial v across cap: 24V)
Homework Equations
from the values of the components, \alpha > \omega_0, the circuit is overdamped, and the following equation can be used: v(t) =A_1 e^{s_1 t} + A_2...
How do you specify, in mathematical notation, that a condition is true for all cases?
For example, I want to say that t=5 for every value of n. Basically like \lim_{n\to\infty}{t=5}, but instead for every value of n, not just as n approaches infinity. Also, how to specify the range of n...
Short version: How accurate is this paper: http://www.wbabin.net/ajay/sharma17.pdf
Long version:
Hello! Physics is not my field of study, but here's my situation: I was having a religious debate and we were discussing the origin of the universe. I decided to quote Lawrence Krauss (a physicist)...
Klein–Gordon equation with time dependent boundary conditions.
Suppose we look for solutions to the Klein–Gordon equation with the following time dependent boundary conditions,
psi(r,theta,phi,t) = 0 zero at infinity
psi(on surface of small ball, B_1,t) = C*exp[i*omega*t]
psi(on...
Say we consider the time independent Klein–Gordon equation, see:
http://en.wikipedia.org/wiki/Klein%E2%80%93Gordon_equation
Lets impose the following boundary conditions, the function is zero at infinity and on some small ball of radius R centered on some origin the function is some...
Homework Statement
I've been given equations that have derivatives as initial conditions, rather than things like u(0,t)=u(L,t)=0
Things like this:
http://img444.imageshack.us/img444/5082/mathu.th.jpg
Uploaded with ImageShack.us
Homework Equations
The Attempt at a...
Homework Statement
Consider a discrete-time system, driven by:
x[k+1] = Ax[k]
for non-zero inital conditions x[0]
a) write the closed-form solution of x[k]. If the system is asymptotically stable how should x(k) behave?
b) what is condition for asymptotic stability?
Homework Equations...
Alternative boundary conditions -- Thomas-algorithm
Hello,
I have to solve a diffusion equation:
MatrixL * Csim(:,i+1) = MatrixR * Csim(:,i) + BoundaryConditions
where Csim = concentration, j = location, i = time.
Boundary conditions are of type Dirichlet (Csim = 5 at j = 1, Csim = 0...
Homework Statement
So we have a string of N particles connected by springs like so:
*...*...*...*...*
A corresponding Hamiltonian that looks like:
H= 1/2* \Sigma P_j^2 + (x_j - x_(j+1) )^2
Where x is transverse position of the particle as measured from the equilibrium position, and...
Homework Statement
I am trying to solve the Laplacian Equation with mixed boundary conditions on a rectangular square that is 1m x 1m.
Homework Equations
\nabla2T=0
.....T=500K
....________
....|@@@@|
T=500K...|@@@@|...T=500K
....|@@@@|
....|______.|
....Convection
....dT...
Homework Statement
If 18.75 mol of helium gas is at 10.0C and a gauge pressure of 0.035atm, calculate a) the volume of the helium gas under these conditions. b) calculate the temp if the gas is compressed to half the voume at a gauge pressure of 1.00atm.
Homework Equations
PV=nRT...
I understand \vec J_{free} only exist on boundary surface of perfect conductors. Copper is close enough and have surface current. Also copper is paramagnetic material which implies \mu_{cu} = \mu_0 or very very close.
In order to find the exact angle of the of the magnetic field inside the...
Homework Statement
Hi
Can anyone help on this. The questions is as follows:
In a double slits experiment using red light, a fringe pattern is observed on a screen at a fixed distance from the double slits. How would the finge pattern change if:
a) The screen is moved closer to the...
In another thread,
https://www.physicsforums.com/showpost.php?p=2973770&postcount=45,
some questions came up about what the conditions are for a spacetime to admit flat spatial slices, and for a spacetime to have a time-independent "scale factor" (see definition below). These questions...
If one could drill a hole to the centre of the earth, presumably the gravitational force on the body would decrease as one passed down this theoretical hole until one could float freely right at the centre where the gravitational force is equal and opposite in all directions with a net effect of...
In an Isothermic and reversible condition why is DH=0? (D=delta) I can understand that DU=0 but DH? but why would DH not change?
DH should also =0 if it was an adiabtic and irreversible condition? since DH=dq/T -> as long as there is no heat transfer DH=0?
Since it's reversible would...
Homework Statement
Find the integral of cot^6(x) without using the reduction formula.
Homework Equations
Potentially any trig identities involving the cotangent
The Attempt at a Solution
I tried splitting up the cot^6 in various ways such as cot^4*cot^2 and cot^2*cot^2*cot*2 but...
Homework Statement
R = { (a+1, b 0) | a, b are real numbers}
S = { (a+b, b, c) | a, b, c are real numbers)
T = R intersect S
I have shown that R and S are subspaces of R^3. Now I have to determine whether T is also a subspace of R^3.
The answer provided is that yes, T is also a...
For part of my lab write up on pendulum motion, my professor wanted us to find out why a pendulum was not a simple harmonic oscillator, and under what conditions it was. He also wanted to show this mathematically.
So far what I have is that if there is no damping(friction?) and if the the...
Its been argued that inflation needs the initial conditions to be finely tuned: eg:
http://en.wikipedia.org/wiki/Inflation_(cosmology)#Fine-tuning_problem
does this paper resolve this problem...
What are the conditions for some matrix to be a density matrix ?
I know of these conditions: 1.) \rho=\rho^{2}
2.) Tr(\rho)=1 (for pure state)
Is this all ?
Homework Statement
Solve: \frac{\partial H}{\partial t} = -4\kappa H^{2}
With initial condition: H(0) = 1/L^{2}
To find: H(t) = \frac{1}{4\kappa t + L^{2}}
2. The attempt at a solution
I tried using Taylor series expansion such that:
H(t)\approx H(0)+t\frac{\partial...
Can one say a body which has the conditions above mentioned be in thermal equilibrium? How does one apply the definition of temperature equilibrium to this situation?
(Physically I think it's possible for a body to be in this situation if some part of it receives heat from the outside and...
Ey guys, this is a problem from my Mech Eng Dynamcis of Machine class
I believe i have the solution already since I've spoken to the lecture'r/tutors who run the subject but would like further clarification just incase I've done something completely wrong.
This is the problem
The...
Hello Everyone,
Is there a list online somewhere of which variable values are 0 and why (conceptually), based on initial conditions? Like I know that for a system at constant volume, w=0. I am looking for a list for the other effects like isothermal, adiabatic, what does pressure= if there is...
Homework Statement
http://img843.imageshack.us/img843/3515/11193469.png
Homework Equations
The Attempt at a Solution
[PLAIN][PLAIN]http://img801.imageshack.us/img801/4829/scan0001i.jpg
An upload of my attempt to solve the problem. Not sure to interpret the results.
A = B...
Hello,
I am facing a diffusion equation..
\frac{du(x,t)}{dt} = D \frac{d^2u}{dx^2}
.. with slightly exotic boundary conditions:
u(0,t) = 0
\frac{d^2u(a,t)}{dx^2}+ \alpha \frac{du(a,t)}{dx} = 0
I expected the solution to be relatively easy to find, since separation of variables quickly...
Homework Statement
Under what conditions are the following true?
a) |\mathbf{a}\cdot \mathbf{b}| =|\mathbf{a}||\mathbf{b}|
b) (\mathbf{a} + \mathbf{b}) \cdot (\mathbf{a} - \mathbf{b}) = |\mathbf{a}|^2 - |\mathbf{b}|^2
Homework Equations
None.
The Attempt at a Solution
a) I...
I am sure to those of you who know GR this will be a simplistic question.
I can only hope there will be a simplistic and definitive answer :-)
Assume a dust cloud of radius=5 and a mass =mc
ANother equivalent mass of condenced matter md=mc
with a radius=1
What would be the...
Homework Statement
Find the voltage across the capacitors in the circuit given under DC conditions.Homework Equations
V=IRThe Attempt at a Solution
The solution is already given (the picture attached was obtained from the solution manual. I have a difficult time understanding how they arrived...
Homework Statement
determine the conditions on a b c and d such that the matrix
a b
c d
will be row equivalent to the given matrix:
1 0
0 1
and
1 0
0 0
Homework Equations
The Attempt at a Solution
I have no idea what its asking, I mean on no. 1:
a = 1 b = 0 c...
Homework Statement
d^2T/dx^2 + S^2*T+B=0
Boundary Conditions:
dT/dx=0 @ x=0
T=T_2 @ x=L
Homework Equations
The Attempt at a Solution
I think you either have to make some type of substitution or find the roots and do it that way.
P.S. This is assignment is a review of diff...
Homework Statement
d^2T/dx^2+S/K=0 Boundary Conditions T=Tsub1 @ x=0
and T=Tsub2 @ x=L
Homework Equations
The Attempt at a Solution
d^2T/dx^2 = -(S/K) <--- intergrate to get
dT=-(S/K)dx+ C1 <--- intergrate to get
T=(-S/K)x+c1+c2
apply both boundary conditions to get...
hi all,
I am trying to solve this PDE by separation of variables, it goes like this:
\frac{\partial u}{\partial t} = \alpha\frac{\partial ^2 u}{\partial z^2} for 0\leq z\leq infty
the initial condition I have is: t=0; u = uo.
the boundary condtions:
z=0; \frac{\partial...
How to derive boundary conditions for interfaces between ferromagnetic material and air?
Please see the attached figure. Any hints will be greatly appreciated!
Hi,
these days I have been trying to understand the essentials of the so-called topological insulators (TBI), such as Bi2Te3, which seem very hot in current research. As i understand, these materials should possesses at the same time gapped bulk bands but gapless surface bands, and spin-orbit...
Homework Statement
For a particular sample of monatomic gas, the rate of change of pressure with volume under isothermal conditions is -2 x 10^7 Pa m^-3. Calculate the rate of change under adiabatic conditions.
Homework Equations
isothermal:
dP/dV = -2 x 10^7
Q = nRTln(Vf/Vi)...