A viscometer assembly includes a first plate with a rail configured to constrain fluid thereon between its edges by surface tension. The folded bit line DRAM device includes an array of memory cells. Another power supply control means controls the gate and drain power supplies at the fall time so that an output voltage of the gate power supply falls later than that of the drain power supply. The method includes transmitting a first signal from a first radio via a first cross-over cable coupled to the first radio and a second radio such that the first signal is received by the second radio. A rotation of the knob in an engaged state is restricted by laying the lever. Therefore, it is possible to accurately correct at least one of a location and an azimuth angle measured by the dead reckoning system, for example, in a home robot having a home base.