We develop a small-signal measurement system on cryogen-free dilution refrigerator which is suitable for superconducting qubit studies. Cryogen-free refrigerators have several advantages such as less manpower for system operation and large sample space for experiment, but concern remains about whether the noise introduced by the coldhead can be made sufficiently low. In this work, we demonstrat...

Materials that consist of a random microstructure can affect ultrasonic measurements--reducing signal strength, increasing noise, and reducing measurement accuracy--through scattering and aberration of the acoustic field. To account for these adverse effects a phase screen model, alongside the stochastic wave equation, has been developed. This approach allows the field and study aberrations to ...

According to the demands of current pipeline detection systems, the above-ground marker (AGM) system based on sound detection principle has been a major development trend in pipeline technology. A novel MEMS acoustic vector sensor for AGM systems which has advantages of high sensitivity, high signal-to-noise ratio (SNR), and good low frequency performance has been put forward. Firstly, it is pr...

introduction: during the thirty years ago noise pollution increased quickly in the urbane communities that motorcycles are chief sources of noise. the objective of this study is reduction of noise emitted from motorcycle exhaust, applying engineering design. materials and methods: in this pre-experimental study, current condition of noise emitted from motorcycle exhaust and physical parameters ...

Statistically optimized near field acoustic holography (SONAH) differs from conventional near field acoustic holography (NAH) by avoiding spatial Fourier transforms; the processing is done directly in the spatial domain. The main advantage of SONAH compared with NAH is that the usual requirement of a measurement aperture that extends well beyond the source can be relaxed. Both NAH and SONAH are...

Noise compensation techniques for robust automatic speech recognition (ASR) attempt to improve system performance in the presence of acoustic interference. In feature-based noise compensation, which includes speech enhancement approaches, the acoustic features that are sent to the recognizer are first processed to remove the effects of noise (see Chapter 9). Model compensation approaches, in co...

Thermocline layer have remarkable effects on acoustic propagation in Persian Gulf environment. So far, no comprehensive research has been conducted to explore thermocline layer, especially its characteristics including top, thickness, and thermal gradient of thermocline in Persian Gulf. Besides, effects of thermocline on underwater acoustic propagation including transmission loss and sound chan...

In this paper, we use LMS filter and design a model with the help of Simulink using MATLAB 11a software. The effect of interference of acoustic noise in speech signals is the most common problem in speech processing. Acoustic noise reduces the intelligibility of speech signals by masking them. We need to suppress this acoustic noise for better communication. By using this technique, the acousti...

The DYNAMAP project has been approved for co-financing by the European Commission through the Life+ 2013 program last May 2014. DYNAMAP aims at the installation of a prototype system in the municipalities of Rome and Milan. It is based on pervasive low-cost hardware network for noise measurement together with some artificial intelligence algorithm to perform the automatic creation of real time ...