A piezoelectric inkjet printhead includes a fluid path forming substrate having a pressure chamber, a piezoelectric actuator formed on the fluid path forming substrate to provide a drive force to the pressure chamber to eject ink, and a damping layer formed on the piezoelectric actuator to dampen a residual vibration of the piezoelectric actuator. The bivouac shelter includes a closure unit, by way of which the body receiving space is closable in a thermally insulating and airtight manner. The inside of the object is scanned with a second ultrasound beam through the second probe to acquire second ultrasound image data associated with the object. The error for the latent construct estimation is controlled by weighting the contribution of the one or more pretest items. Nodes are removed from this single candidate cluster in accordance with similarity and connectivity criteria, to arrive at a true cluster.