“…The main difficulty for scalar conservation laws with a boundary effect is to have a good formation of the boundary condition. Namely, for a fixed initial value as (1.1) 2 , we really cannot impose such a condition on the boundary as (1.1) 3 , and the boundary condition is necessarily linked to the entropy condition (The approach for dealing with the boundary in [6] has been followed by many authors [3,[11][12][13][14][15], who extended the previous results in different directions). In other words, the weak entropy solution u(x, t) for (1.1) does not admit a trace at the boundary, namely, u(0, t) does not always equal u b (t), whereas, as a viscosity approximation of the weak entropy solution for (1.1), the solution of the initial boundary value problems of parabolic Equation (1.2) does admit a fixed trace at the boundary.…”