In the series regulator, when an external starting voltage source has started operation, a bias current is supplied from a fourth transistor to a reference voltage circuit, and a reference voltage is supplied form the reference voltage circuit to an amplifier. 8 times the radial distance DS between the radially innermost and radially outermost points of the circumferential reinforcement and less than or equal to 1. A value or values of one or more transmission condition parameters indicative of transmission conditions in the network are acquired, where these transmission condition parameters are specific for a second layer provided lower than said first layer. When the installation of the server is completed, servers that can process, within a predetermined period, a volume of requests at that time and a volume of requests retained by that time are secured. The at least one reaction clutch corresponding to the first gear engagement is fully engaged when engine load is below the predetermined value.