Information regarding the current state in the market is used to prevent orders from crossing. A driving machine is mounted to the fan housing for driving the fan. The second wireless device receives a code transmitted from the first wireless device when the button is pressed, determines if the code has been previously received, and accepts the code if not previously received. The edge indications for successive frames in an MPEG sequence are compared to each other in various ways in order to detect scene changes. By adopting such a method, it is possible to fabricate a specimen for high reliability observation, analysis, and measurement entailing less contamination, in a shorter time and with efficiency.