This invention relates to a method for determining a quality for a data clustering, said data clustering resulting in a plurality of clusters each cluster having a cluster identifier, the method comprising the steps of:. In the boot voltage generating method, a VID reference voltage generation circuit is provided. An air purifying respirator draws air from outside the protective suit through a filter, supplies filtered breathing air via a breathing hose to a space within the face piece, and supplies filtered ventilating air via a ventilating hose to the interior of the protective suit. A variety of materials can be used in the inkjet printing technique and the alignment concerns associated with the use of multiple lithographic steps and, in particular, with the use of plastics substrates, are substantially alleviated. The gearbox device includes a hollow gearbox input shaft adapted for inputting the first torque, a transmission unit arranged at least partially within the hollow gearbox input shaft and adapted for converting the first rotational speed into the second rotational speed, and a gearbox output shaft adapted for outputting the second torque.