We consider the following inverse problem of finding the evolution parameter p(r) dnd the solution ~( x .I ) such thdt
(a,,(x3 [ ) U , , + b,(x, t , U ) ) x v,(x) = g ( x , t , U ) on Sr,.,=I and I,, q ( x , t)u(x, t ) dx= E(t) Osts Twhere Qr= C2 X (0, T I , T>O and 52 is an open bounded region in R" with boundary 8D as smooth as needed throughout this paper; v ( x ) = ( v , ( x ) , vz(x), ..., v J x ) ) is the outward pointing normal direction on asl; uir, g, F, a,,, b,. q and E are given functions. The notion of a weak solution for the pair ( U , p ) is formulated. The existence, uniqueness and continuous dependence upon the data of the solution ( U , p ) are demonstrated for F(x, t , U ) = G(x, t , U ) + H ( x , t)p(r) and F(x, t , U ) = G ( x . t , U ) + ~( x , t ) p ( t ) .