A method of forming a rotorcraft blade is provided. This apparatus repeatedly executes, in principle, a control cycle in which a pressure-reducing control, holding control and linear pressure-increasing control make one set, after ABS control start conditions are satisfied. This method may use many types of code sequences, one or more of which are rapid acquisition sequences of length L that have average acquisition phase searches rlog2L. This uniformalizes the flow rate distribution of the supply air flow from the air outlet and forms a stabilized air curtain flow. Compressed isosurface data can be stored in a data storage device or transmitted through a communication medium to a remote computer system, where the decoder process is executed. In response to input of a new image, the system communicates information of a moving object included in the newly inputted image into the regression tree, and determines a size of a person included in the new image based on a resultant value of the regression tree.