Low frequency vibration occurs especially in ground transportation, either as a cause in adjacent environment or within the vehicle itself. The piezoelectric accelerometers commonly used for vibration measurement are not suitable, hence other sensors capable of measuring accelerations down to sub-hertz region have to be used. Based on some previous experience with MEMS acceleration sensors a th...

OBJECTIVES To investigate changes in digital circulation during and after exposure to hand transmitted vibration. By studying two frequencies and two magnitudes of vibration, to investigate the extent to which haemodynamic changes depend on the vibration frequency, the vibration acceleration, and the vibration velocity. METHODS Finger skin temperature (FST), finger blood flow (FBF), and finge...

The effects of input shaping on trajectory following were investigated by simulating the response of a fourth-order system with orthogonal modes and conducting experiments on an XY positioning stage. For nearly all values of damping and frequency ratio, the shaped inputs result in significantly better trajectory following than unshaped inputs. When the trajectory improvement techniques in this ...

A robust vibration absorber reduces vibrations of a system over a range of frequencies. Passive vibration absorption is achieved with a tuned mass and spring (known as a dynamic vibration absorber (DVA)). This is a simple, low cost method of reducing vibrations at a single frequency; however, in order to achieve robust absorption a heavy mass is required. Active vibration control is achieved wi...

Occupationally used high-frequency vibration is supposed to have negative effects on blood flow and muscle strength. Conversely, low-frequency vibration used as a training tool appears to increase muscle strength, but nothing is known about its effects on peripheral circulation. The aim of this investigation was to quantify alterations in muscle blood volume after whole muscle vibration--after ...

OBJECTIVE We aimed to assess the vocal-fold vibration of patients with moderate-to-severe Reinke's edema using high-speed digital imaging (HSDI) and videostroboscopy and to confirm HSDI usefulness in examining the vocal folds with Reinke's edema. METHODS We examined the vocal folds of seven patients (six severe and one moderate; six females and one male; aged 55-74 years; mean 64.7 years) wit...

A new frequency weighting method to assess hand-arm vibration exposure is proposed in this paper. The influence of frequency components was first estimated using the method of multivariate analysis, then a simple form of the weighting curve was introduced. Compared with the frequency weighting in the current ISO 5349-1 (2001), the proposed weighting can better explain the relationship between r...

One of the significant engineering applications of the elastic metamaterial (EMM) is for low-frequency vibration attenuation because of its unusual low-frequency bandgap behavior. However, the forbidden gap from many existing EMMs is usually of narrow bandwidth which limits their practical engineering applications. In this paper, a chirallattice-based EMM beamwith multiple embedded local resona...

A new approach called the“Variational Theory of Complex Rays”has been developed in order to calculate the vibrations of slightly damped elastic plates in the medium-frequency range. The solution of a small system of equations, which does not result from a fine spatial discretization of the structure, leads to the evaluation of effective quantities (deformation energy, vibration amplitude,. . . ...