A method and system allows conversion of three-dimensional data from a default coordinate frame to an arbitrary user-selected coordinate frame. In some embodiments, the device can prevent a child from being burned or uncomfortable by the heat of a swing seat or car seat by minimizing thermal transfer between a child’s skin and the swing seat for an adequate amount of time. The windowed portions obtained in the training phase exhibit varying degrees of misalignment with the corresponding symbol boundaries. During non-drive period of the driven element, the bearings contact a circular arc surface of the second cam, and further the recesses contact the plurality of rollers, to restrict rotation of the driven element. The output buffer includes a variable resistance circuit connected to a path between the first power source supply terminal and the power source line, the variable resistance circuit serving to change a resistance value thereof in accordance with a magnitude of a total sum of the currents. Present invention is characterised in that the outer conductor is made of an elongated tubular compartment having an elongated opening along one side of the compartment, and that the inner conductor is suspended within the tubular compartment by means of dielectric support means.