A game bird decoy assembly and a method for making same includes a lightweight planar member contoured in the form of the silhouette of a game bird. The simulation tool comprises: a first algorithm for modeling the behavior of an LPAR operating in a time slice dispatch mode; and a second algorithm for modeling the behavior of a plurality of LPARs. The actuator also comprises means for selectively restricting the swinging movement of the operation key 2 to either of the two directions. An output stage is coupled to the input stage and receives the modified control signal. A snow guard is provided on the ski body, to prevent snow or ice from hindering operation of the wheel unit.