Received: December 18, 2015 Revised: September 29, 2016 Accepted: October 18, 2016 Abstract: Background: Aiming at the challenges in control and perdition of roof strata which caused by the complexity of coal mine roof, the force and vibration characteristics of drill bit have been analyzed considering the coupling vibration between drill bit and coal rock, and the characteristics of coupled vi...

In order to understand critical vibration of a drill bit such as stick-slip and bit-bounce and their wave propagation characteristics through a drill string system, it is critical to model the torsional, longitudinal, and flexural waves generated by the drill bit vibration. Here, a modeling method based on a vibration transfer matrix between two sets of structural wave variables at the ends of ...

Drilling engineering is a high input and risk underground project, which needs the real-time down-hole diagnosis and forecast technique. Drilling string vibration signals contain full and complex vibration waves, which contains the vibration of the drilling string by itself, the vibration stimulated by the interaction of bit and the formation, the vibration induced by colliding between drill st...

This paper investigates the possibility of communicating through vibrations. By modulating the vibration motors available in all mobile phones, and decoding them through accelerometers, we aim to communicate small packets of information. Of course, this will not match the bit rates available through RF modalities, such as NFC or Bluetooth, which utilize a much larger bandwidth. However, where s...

A probabilistic bit (p-bit) is the fundamental building block in circuit of computing (PC), and it produces a random binary bitstream with tunable probability. Utilizing randomness induced by thermal noise-induced lattice vibration ferroelectric (FE) material, we propose p-bits based on stochastic FET (FeFET). The domain dynamic revealed to play crucial roles FE p-bits’ stochasticity, as coupli...

The interaction between friction and vibration is a widely recognised source of inefciency in all mechanical systems. The nature of this interaction is very dependent on the dynamic environment and its control requires a detailed understanding of the mathematical structure governing the stability of this environment. Although the fundamental causes of friction-induced intermittent motion have b...