Graph-Based Semantic Web Service Composition for Healthcare Data Integration

Algorithm 1

Forward search.

Input: and are the requested input and output parameters of WS searching (I/O dependency)

Output: is a set of discovered paths of potential web services (sets of operations)

procedure FWS(u,v)

          //V is a set of discovered nodes

        //Q is a set of queue of ordered pairs of vertices and paths (sets of arcs)

 while do

      //get the ordered pair of vertex and path (set of arcs) in queue as

  if is equal to then     //check if t is the destiny vertex of I/O dependency

           //add w into

  end if

  for      //to find the adjacent arcs of t through a query “select ?e where {?e tail ?t.}”

            //create w_j as a clone arcs set of w

           //append an arc to arcs set

       //find head vertex of arc e from a query “select ?u_i where {?e head ?u_i.}”

   if is not in then    //check if u_i have not been visited

         //add u_i to the set of visited vertices

    enqueue to     //put order to Q for the next round in while loop

   else if then

    enqueue to     //put order to the if is equal to to find other paths of I/O

   end if

  end for

 end while

 return            //return when is empty

end