The detection and recording of vibration emission from human joints, a technique which we have termed "vibration arthrography", is a sensitive, non-invasive method for the objective study of the locomotor system. Using vibration sensors attached to bony prominences around the knee, we studied the joints of both normal and symptomatic subjects. Normal subjects produced three signal types--physio...

The use of vibration signals for internal combustion engines diagnosis is now well established for several applications such as knock detection or valve mechanics behaviour assessment. If standard knock detection can be performed in real time, diagnoses are generally carried out off-line due to algorithm complexity. Our aim was to get some insights on the time-frequency properties of the vibrat...

This study aimed to investigate the effects of two different racket models and two different forehand drive velocities on the three-dimensional vibration behavior of the racket and shock transmission to the player's wrist under real playing conditions. Nine tennis players performed a series of crosscourt flat forehand drives at two velocities, using a lightly and a highly vibrant racket. Two ac...

This paper concentrates on cavitation detection using discrete wavelet transform by classifying the pump vibration signal. Vibration signal acquired from centrifugal pump cavitation test rig carry more information about the cavitation classes. In this paper two classes has been defined namely, no cavitation class and developed cavitation class. This method uses the deviation from zero mean valu...

http://dx.doi.org/10.1016/j.anbehav.2014.09.030 0003-3472/© 2014 The Association for the Study of A Cooperative activities in advanced insect societies are organized by complex systems of communication signals that may have evolved from interactions among nestmates in primitively social ancestors. Primitively social colonies are organized by dominance and aggression, which suggests that some co...

Heterodyne holography is an extremely versatile and powerful holographic technique that is able to fully control the amplitude, phase and frequency of both the illumination and holographic reference beams. Applied to vibration analysis, this technique is able to detect the signal of the carrier or the one of any vibration sideband. A complete analysis of the vibration signal can thus be made, a...

Research shows that multi-fractal can not only exhibit the singular probability distribution form of the fractal signal completely, but also increase the fine level of signal geometrical characteristics and local scaling behavior. Based on multi fractal dimension calculation of time-frequency matrix of vibration signal of rolling bearing in this paper, energy distribution characteristics of tim...

To detect external vibration signals on the latticed fence structure, distributed fiber optic sensor using Sagnac interferometer was fabricated and tested. Because of easy construction Sagnac interferometer was selected rather than MachZehnder type. The latticed structure fabricated with dimension of 180cm in width and 180cm in height, the optical fiber, 50m in length, distributed and fixed on ...