One or more labels are associated with a data object. The methods include processing the exhaust gas before each stage of the multi-stage gas compressor to clarify the inert gas in the exhaust gas, processing the exhaust gas after each stage of the multi-stage gas compressor to clarify the inert gas in the exhaust gas and compressing the inert gas processed for export from the inert gas processing system. The low color scale driving circuit generates a first analog signal, a second analog signal, a third analog signal and a fourth analog signal according to the digital signals outputted from the timing controller for driving a liquid crystal panel. The invention converts faces of the base mesh into parametric elementary surfaces and trims at least one of said parametric elementary surfaces located in the vicinity of the extraordinary vertex.