A Software Defined Network includes a plurality of forwarding devices and a routing control device located separate from the forwarding devices. A heat exchanger shell is connected to an exhaust port of the engine, and has an output port. A surface shape of the shielding case is formed in a shape not overlapping the antenna. The polishing apparatus supplies abrasive particles to the polishing surface stably by dressing and allows high-speed polishing of the substrate. The vibrating element 6 is fixedly mounted on the driven element 5 in a state where the contact portion 66 abuts on the contacted element 51. The backrest and the elements forming the shoulder supports are rigid.