BTDC Before Top Dead Center
water diversion from the upper Yangtze River in the south to the upper Yellow River in the north
bias between the mass center and siffness center
center to center communications
center to center distance
1221 upper working face
2×2 Upper Triangular Operator Matrixes
95% Upper confidence limit
Aberdeen Upper Reservoir
Accommodation above the Upper Deck
accurate upper bound solution
Acquired absence of both upper limbs [any level]
Acquired absence of upper limb above wrist