We derive several new reformulations of the Hubeny-Rangamani-Takayanagi covariant holographic entanglement entropy formula. These include: (1) a minimax formula, which involves finding maximal-area achronal surface on timelike hypersurface homologous to D(A) (the boundary causal domain region A whose we are calculating) and minimizing over hypersurface; (2) max V-flow in maximize flux through d...

numerous parameters influence bit selection process, which considering all them is not normally feasible. existing methods use limited number of these parameters to choose a suitable bit for a specific drilling condition. one of the widely used methods is cost per foot. specific energy and drilling strength are another methods currently used for bit selection. different methods of bit selection...