HP Unix/Oracle Defunct Processes Hanging

HP Unix/Oracle Defunct Processes Hanging Around
I’m using a warehouse management software on HP11.0 with Oracle 817 I have another program on NT that connects to the HP via RPC connection.When user logs onto the NT client it spawns a process on HP. When they log off NT client the spawned process should die, but sometimes these processes and their Oracle shadow processes hang and create a defunct process. these continue to run and eat CPU. How can I stop these from happening ?