THE POWER SPECTRAL DENSITY OF THE H-TERNARY LINE CODE: A SIMULATION MODEL AND COMPARISON

Abstract A method to locate sound sources using an audio recording system mounted on an unmanned aerial vehicle (UAV) is proposed. The method introduces extension algorithms to apply on top of a baseline approach, which performs localisation by estimating the peak signal-to-noise ratio (SNR) response in the time-frequency and angular spectra with the time difference of arrival information. The proposed extensions include a noise reduction and a post-processing algorithm to address the challenges in a UAV setting. The noise reduction algorithm reduces influences of UAV rotor noise on localisation performance, by scaling the SNR response using power spectral density of the UAV rotor noise, estimated using a denoising autoencoder. For the source tracking problem, an angular spectral range restricted peak search and link post-processing algorithm is also proposed to filter out incorrect location estimates along the localisation path. Experimental results show the proposed extensions yielded improvements in locating the target sound source correctly, with a 0.0064–0.175 decrease in mean haversine distance error across various UAV operating scenarios. The proposed method also shows a reduction in unexpected location estimations, with a 0.0037–0.185 decrease in the 0.75 quartile haversine distance error.

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Methodology and Power Spectral Density Limits Proposal for Non Intentional Emissions in frequencies below 150 kHz

2020 IEEE International Symposium on Power Line Communications and its Applications (ISPLC) ◽

10.1109/isplc48789.2020.9115401 ◽

2020 ◽

Author(s):

Noelia Uribe Perez ◽

Ibon Arechalde ◽

Marta Castro ◽

Alberto Sendin ◽

Iker Urrutia ◽

...

Keyword(s):

Spectral Density ◽

Power Spectral Density ◽

Power Spectral

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Numerical and Experimental Studies of Pipe Vibration Generated by Elongated Orifice

Volume 5: High-Pressure Technology; Rudy Scavuzzo Student Paper Symposium and 24th Annual Student Paper Competition; ASME Nondestructive Evaluation, Diagnosis and Prognosis Division (NDPD); Electric Power Research Institute (EPRI) Creep Fatigue Workshop ◽

10.1115/pvp2016-63983 ◽

2016 ◽

Author(s):

Wenjie Bai ◽

Quan Duan ◽

Zaoxiao Zhang

Keyword(s):

Spectral Density ◽

Power Spectral Density ◽

Flow Rate ◽

Vibration Response ◽

Frequency Range ◽

Fluctuating Pressure ◽

Outlet Pressure ◽

Wall Pressure Fluctuations ◽

Power Spectral ◽

Pipe Vibration

Hydraulic tests for elongated orifice-induced wall pressure fluctuations and vibration in pipeline have been carried out. The regulating modes of test system consist of maintaining outlet pressure to increase flow rate and maintaining flow rate to decrease outlet pressure. Both regulating modes would increase the possibility of cavitation within elongated orifice, which has been confirmed by numerical simulation in present study. Statistical characteristics of the fluctuating pressure and structure vibration response have been studied. The standard deviation analyses indicate that the amplitude of fluctuating pressure is mainly determined by flow rate. The power spectral density analyses show that the energy of the fluctuating pressure behind elongated orifice is concentrated in lower frequency range and it can be divided into two parts in this test: the pressure pulsation excited by plunger pump and the random fluctuating pressure produced by elongated orifice’s disturbance. The power spectral density of pipe vibration response shows that the lower frequency of pipe vibration response can be ascribed to the fluctuating pressure behind elongated orifice and the characteristic frequencies corresponding to cavitation within elongated orifice are in the higher frequency range.

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