In an apparatus for polishing a substrate, including a polishing platen for mounting the substrate thereon, a polishing head, a polishing pad adhered to a bottom face of the polishing head, and a rocking section for rocking. Each shuttle car includes an x-shuttle that supports two z-shuttles. In response to the first hardware node failing to identify the regular expression in the data packet, the data packet is forwarded to a second hardware node in the network interconnect for further examination of the data packet in order to search for the regular expression in the data packet. Such formation of non-linearly profiled surface region is effective in preventing a friction noise from being generated between the lock plate and the stay element. The ozone generator and housing can be part of a buoyant floating platform that is also equipped with solar power collector panels to provide a recharging current for the battery; a robotic, self-propelled pool cleaner; or a skimmer filter assembly that can include a solar panel under a solar transmissive cover that is flush mounted in the walk area alongside the pool.