Motivated by recent observations which detect an outer boundary for starless cores, and evidence for time-dependent mass accretion in the Class 0 and Class I protostellar phases, we reexamine the case of spherical isothermal collapse in the case of a finite mass reservoir. The presence of a core boundary results in the generation of an inward propagating rarefaction wave. This steepens the gas ...

Introduction: Incipient faults of distribution networks, if not detected at an early stage, could evolve into permanent and result in significant economic losses. It is necessary to detect incipient improve power grid security. However, due the short duration unapparent waveform distortion, are difficult identify. In addition, usually have a small data volume, which compromises their pattern re...