A waterproof structure for a portable electronic device includes a housing, an interface member, a waterproof circuit board, a chamber, and a main circuit board. A first code stored on the programmable device tracks time on the programmable medium. When a transceiver receiving packets transmits a request to retransmit in the case of failure in reception of at least one packet, a transceiver transmitting packets is configured to retransmit each packet requested as a response to the request. The exemplary system is expandable for more efficiency when the number of turns in the helical shape of blades is increased. In addition, another method and device for analyzing positions are disclosed.