Zero-IF receiver has some advantages, such as small factor, low cost and easily integrated on a chip. They make it competitive of RF receivers. However, DC Offset and flicker noise, etc., have profound effects in zero-IF receiver, which need not be considered in super-heterodyne receiver. Following a major study of flicker noise, possible solutions are given, especially those based on the passi...

conclusions according to the factory noise map, except for the control rooms with 81 dba noise, other cases of measuring stations were higher than the standard exposure of 85 dba noise. as a result, the implementation of control strategies, such as inspection and performance of control systems and insulation of the control room to prevent unnecessary exposure noise, are necessary. background st...

Introduction The acoustic noise generated from the MRI system is a serious safety concern as well as a technical challenge for MR and acoustic noise control scientists. The emitted high noise levels can be both annoying and harmful to patients and healthcare workers, especially after long term exposure. Although various passive methods have been proposed to deal with this problem, active noise ...

We study a minimal shell model for the advection of a passive scalar by a Gaussian time-correlated velocity field. The anomalous scaling properties of the white noise limit are studied analytically. The effect of the time correlations are investigated using perturbation theory around the white noise limit and nonperturbatively by numerical integration. The time correlation of the velocity field...

Adaptive-passive vibration and acoustic control systems can provide significant attenuation without requiring significant power compared to an active control system. The control system includes an algorithm to evaluate a costfunction to be minimised, which is typically a time-averaged multiplication of the vibration or noise on the resonator and at a point in the system where the disturbance is...

A model is presented for the complete passive fathometer response to ocean surface noise, interfering discrete noise sources, and locally uncorrelated noise in an ideal waveguide. The leading order term of the ocean surface noise contribution produces the cross-correlation of vertical multipaths and yields the depth of sub-bottom reflectors. Discrete noise incident on the array via multipaths g...

In the design of bridges with large spans, the significant values of the moments at the main deck-structure require very heavy members, either in the case of a beam or a truss deck-structure. In order to minimize the influence of bending moments, several applications of passive control of displacements using cable nets are herein proposed. The base for all the proposed systems is the cables sup...

Recent research activities in elastic metamaterials demonstrate a significant potential for subwavelength wave propagation control owing to their interior locally resonant mechanism. The growing technological developments in electro/magnetomechanical couplings of smart materials have introduced a controlling degree of freedom for passive elastic metamaterials. Active elastic metamaterials could...

Previous studies have shown that small changes can be monitored in a scattering medium by observing phase shifts in the coda. Passive monitoring of weak changes through ambient noise correlation has already been applied to seismology, acoustics, and engineering. Usually, this is done under the assumption that a properly reconstructed Green function (GF), as well as stable background noise sourc...