Digging through my archive of Maple files, I found this animation from some yeara ago:

prob-02-quad.mw

@ibndirac I don't quite understand the setting of this problem. On the one hand you impose boundary conditions at x=0 and x=L, perhaps implying that you seek a solution g(x,t) where 0 < x < L. On the other hand, to determine beta, you need the values of g(x,t) for all x ∈ (−∞,∞). What is the domain of g? Some clarification is needed.

You will get more helpful responses if you post a real worksheet rather than snippets, especially since the snippets that you have posted seem to be inaccurate.  For instance, what is the meaning of the derivative diff(g(x, t), v) since g(x,t) has no v in it?

To post a worksheet, click the big fat green arrow that appears in the toolbar of the window where you edit your message for posting.

I don't think referencing a web page is a good idea in a thesis.  If you saw a reference to a web page in a thesis written on 1995, would you expect to find it today?

Furthermore, a web page is a living document; it may be changed/updated without notice.  What you see now may not be what your readers will see two years from now.  In fact, the web page that you have referred to, corresponds to Maple's help page "?Groebner[Basis]".  At the bottom of that page in Maple 2018.1 we have:
     The Groebner[Basis] command was updated in Maple 2018.

It may be more helpful to your readers if you cite one or more of the published articles that appear at the end of the help page "?Groebner[Algorithms]".

@rahinui On Maple 2017.3 and 2018.0 (on 64 bit Linux) I am getting the expected answer {f(t, x) = _F1(x)}.  Something strange must be happening at your end. Check!

Did you try applying dsolve() to the system? If you did, what didn't you like about the result?  Post your worksheet so that others won't have to retype the equations.

@Carl Love Maybe there is something to that, however
caption = typeset(a^(b^(c^d))+u^(v^(w^t)))
takes up significantly larger space but causes no problem.

Here is the desired potential function:

V := unapply(piecewise(x < x__1, psi__1(x), x < x__2, psi__2(x), psi__3(x)), x);

If you meant to ask something else, then you need to be more specific.

@student_md Essentially your entire calculation should be enclosed in a procedure.  In the attached worksheet I have made minimal modifications to your worksheet to do that.  It's likely that your calculations can be streamlined and improved significant;ly.  I haven't attempted that.

Download worksheet:   code-ver2.mw

@student_md 

In your worksheet you have all the necessary pieces but some good organization is lacking.

As a first step, instead of specifying J at the top level, see if you can write a procedure that receives J as an argument and produces the desired graphics for that particular J, as in:
frame := proc(J)
     ...
     calculations here
     ...
     return plots:-display([AA, BB]);
end

Next, generate the sequence of frames:
frames := seq(frame(J), J=0..5):

Finally, display the animation:
plots:-display([frames], insequence);

@griffgruff Your statement is clear enough although I don't understand why you asssume that del(u) is normal to the boundary.

That would be the case only when the Dirichlet data is constant.  But you say that it isn't.  If so, then your del(u) is not normal to the boundary, and therefore you cannot calculate the vector n from it.

You need to give that some additional thought.

@griffgruff You say that u is a solution of a PDE and at the same time u represents the domain's boundary. That would be the case only if the boundary is a level curve of u, that is, u(x,y) is specified as a constant on the boundary.

@Kitonum You seem to have misiterpreted the question.  The vectors n and del(u) are unrelated.  The desired answer is  n(x,y)^+ . del_u(x,y), where

n := (x,y) -> < n1(x,y), n2(x,y) >;    # assuming n1*2 + n2^2 = 1
del_u := (x,y) -> < diff(u(x,y),x), diff(u(x,y), y) >;
 

@waseem

Do:

dsol := dsolve(ODEs);

to see what the general solution looks like.  Then you may apply any boundary conditions that you like.

@ivanfanthony You have four equations in the five unknowns, S(t), I(t), E(t), J(t), R(t).  You need to supply one more equation.

Additionally, the symbols I and gamma are reserved for internal use in Maple.  You should use some other symbols instead of those.