A system and method wherein the parameters used for face recognition are determined via an evolutionary algorithm, such as a genetic algorithm. The variety successfully propagates from softwood cuttings and is suitable for year round production in commercial glasshouses. A plurality of corresponding MV maps is constructed in a time domain according to the MVs. The user pivots his lower legs about the knee joints to produce an oscillating pivoting motion. The gas-suctioning device suctions the gas so the path of gas having contacted the sample rod bends when the extension direction of the sample rod and the blown direction of the gas form an acute angle.