I am studying a nonlinear wave equation and trying to reproduce the energy balance method shown in a research paper. First, the original partial differential equation is reduced to an ordinary differential equation using a traveling wave transformation. After obtaining the reduced equation, the paper rewrites it in a form suitable for the energy balance method and derives the corresponding variational principle and Hamiltonian invariant. Then a trial periodic solution in cosine form is assumed. Using the Hamiltonian invariant and some initial conditions, the parameters of the trial function are determined and a periodic solution is obtained.

I would like to know how to implement this procedure in Maple. Specifically,  compute the Hamiltonian invariant from the equation, substitute the cosine trial function, and determine the unknown parameter in the trial solution using the energy balance method. I will attach images from the paper that show the derivation steps I am trying to reproduce. Any guidance on how to perform these symbolic steps in Maple would be very helpful.

f-s.mw

once i founded but  i lost the technique and i can't remember how i can reach the point how to find thus parameter and find the solution of pde

t1.mw

my question is a little bit long but is not complicated, i want find thus  unkown but  realy i am don't know how apply on it by maple, i have two best paper which explain very well i just want to find thus dimensional Lie algebra which is be invariant or not satisfy condition or not which i have to used or which i have not to use it also the importan part how find them in paper 1 first , for equation fisher 
How find eq(29) which is i think is two -dimensional Lie algebra of equation, also the best part is reduction which by apply this we can change PDE to ode but i don't know how apply eq(31) or even find it yet  is related to eq(27-28)  and by replacing equation eq(34) we can get our ode i am just loking for the ode, for the eq(76) and eq(85) have same procedures,  i will mention the paper link too 

Lie.mw

paper-1

paper-2

I am trying to calculate the stability of my solution using this integral test:

U = 1/2 * ∫ u(x,t)^2 dx

Then I want to compute the derivative with respect to epsilon and check if the result is greater than zero or less than zero.

I tried to do it in Maple but it is not working correctly.

Also, I want to substitute random numbers for the parameters to test stability. I prefer to use simple integer values like 1, 2, 3, etc., not decimal numbers. When I try random values, sometimes the result does not evaluate or gives complicated output.

S-test.mw

is been a while i work on it but i can't figure out where is problem and even my solution is so far from it when numerically i tested , i got same outcome as the paper did maybe is  long but it is same and maybe have some typical different but they are same , the problem in here is that which when i substitue is not my answer i don't know where is my mistake ?

pde-te.mw

f18.mw

f19.mw