A dynamic pressure bearing device having a structure in which forces in the radial and thrust directions can be easily balanced with each other, and lubricant hardly leaks is provided. A shaft may be operatively connected to the receiver and configured to attach to the bone. The dividing place between the lower-tool operative part and the lower tool base plate is disposed such that all the workpiece-specific designs are present exclusively on the lower-tool operative part, while the lower tool base plate is the same, without change, for all workpieces to be machined. The system creates at least one connection between the enterprise social network and the market social network. An output of the amplifier in the first configuration is an output of the video synchronization signal generating circuit.