Network connectivity may be managed on a computing device. It applies an advanced variation of stack walking called multi-mode stack walking to the entire system level and generates the unified trace where the user code and kernel events are integrated. The braided reflective sleeve is composed of braided narrow width reflective strips. The method is useful for humans who are operating vehicles or machinery, who are suffering from cardiovascular disease or related complications, who are pregnant, or who are preparing for sleep. A width of a middle portion of one of the active areas in the up-to-down direction being smaller than a width of a portion of the active areas upper of the middle portion and a width of a portion of the active areas below the middle portion.