Abstract There are fan noise and transformer sources inside the converter cabin which may bring environmental pollution through airborne or structural borne paths. In order to identify contribution of each source its path, transfer path analysis test was performed. Take full load working condition at speed as an example, contributions air noise, 88.33%, 3.79%, 7.37% 0.51% respectively. The is 9...

Motivated by their functional conformity, micro-cantilever-based MEMS oscillators are investigated in this study as structure-integrable transducers for the acquisition of guided ultrasonic waves fiber–metal laminates. While acceleration-sensitive limited maximum frequency, presented displacement-sensitive oscillator is operated quasi-free fashion a seismometer, making it particularly sensitive...

Air-borne acoustic based condition monitoring is a promising technique because of its intrusive nature and the rich information contained within the acoustic signals including all sources. However, the back ground noise contamination, interferences and the number of Internal Combustion Engine ICE vibro-acoustic sources preclude the extraction of condition information using this technique. There...

Equal-arm interferometric detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower lev...

This study arose from the need to control noise in naval vessels to reduce their detectability and hence vulnerability to enemy attack. In this report a detailed review of sensor and actuator technologies that could be used for active noise and vibration control in ship structures has been provided. The review focused on a wide range of sensor and actuator materials, such as piezoelectric and e...

The evaluation and control of the trains induced vibrations needs even more attention in the case of underground tracks which passes near to monuments and historical sites. The rail corrugations which occur due to the wheels’ impulse loads during the operation period of underground railway tracks, usually amplify the ground borne noise and vibration. In the current study, the mentioned phenomen...

this article presents a new subspace-based technique for reducing the noise ofsignals in time-series. in the proposed approach, the signal is initially representedas a data matrix. then using singular value decomposition (svd), noisy datamatrix is divided into signal subspace and noise subspace. in this subspace division,each derivative of the singular values with respect to rank order is used ...