A structure of redundant arrays of inexpensive disks with servers is disclosed. The stepping motor is capable of rotating with not only high speed but also less undesired vibration and noises, and enabling a simpler, smaller manufacturing equipment thereof to be constructed. Also disclosed is a method of growing early stage human embryos to transfer ready blastocysts. A reference key speed is determined that corresponds to a rate of change of a distribution of the tracked traffic with respect to the reference key. , the heart rate, is constructed and is run independently for each channel to generate predictions of the parameter. The method includes ascertaining an intended topology of the N-stage switch network, creating a list of switch boards present in the N-stage switch network, and determining a switch board connection pattern.