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The method of compressive sensing is applied to moving source data created by simulation to estimate the mode wavenumbers, mode depth functions and mode amplitudes without any environmental acoustic information, such as sound speed profile or bottom properties. The method needs in principle only data covering a short range span and is thus applicable to a range-dependent environment to estimate the...
In this paper we present a proof-of-concept for an hydro acoustic fish-tag position estimation and tracking system. In our field-tested concept, a formation of Unmanned Surface Vehicles (USV) creates a mobile array of low-cost hydro acoustic fish-tag receivers. The array of receivers is able to estimate fish-tag locations and follow the fish on open waters, significantly increasing capabilities as...
The speed of the target can be estimated by the sound pressure cross-correlation of the line spectrum of the moving target at different time intervals. However, a slight deviation of the line spectrum has a significant influence on the estimated result. In this paper this phenomenon is analyzed from the theory, then the speed of the target is estimated when the line spectrum is biased. Experimental...
A cyberphysical network of insect biobots or biological robots could aid first-responders for search-and-rescue applications in uncertain disaster environments. In such networks, the nodes are insect biobots equipped with miniature backpacks utilizing a system-on-chip. These applications demand fine-grained, real-time localization of the sensor nodes. In this paper, we use a combination of radio-frequency...
Signal source localization and separation are key tasks for many applications. In this paper, a new deterministic method is proposed for estimating the 3D location and separating multiple acoustic or vibration sources, simultaneously active. The method is based on TDOA measurements obtained via crosscorrelation. Then, with the information from the estimated locations, source separation is achieved...
Transmitting large amounts of data such as videos underwater is an important yet challenging problem in the harsh underwater environment in which radio-frequency waves are absorbed for distances above a few tens of meters, optical waves require narrow laser beams and suffer from scattering and ocean wave motion, and acoustic waves—while being able to propagate up to several tens of kilometers—lead...
Multi-channel speech enhancement algorithms rely on a synchronous sampling of the microphone signals. This, however, cannot always be guaranteed, especially if the sensors are distributed in an environment. To avoid performance degradation the sampling rate offset needs to be estimated and compensated for. In this contribution we extend the recently proposed coherence drift based method in two important...
Objective markers obtained from acoustic analysis of speech are of great importance for clinical evaluation of voice disorders because they are non-invasive and provide a severity index of the disorder which allows clinicians to monitor the progress of patients and documents quantitatively the degree of perceived hoarseness. The object of the present study is to introduce a fractional order long-term...
In this paper, we present a new approach of time of flight (TOF) estimation using wide band signals, based on compressive sensing (CS) reconstruction in warped domain. In real conditions, constraints related to signal's transmitting/receiving (such as the transducers configuration or the experimental setup) can affect the informational content of the signal. Thus, the received signals need content...
Knowing the wind speed is an important factor that includes several scientific areas. For the types of existing anemometers, the ultrasonic model is what can be used in most applications. As part of the necessary calculus for wind speed acquisition, it is needed to find the correct ultrasonic echo emitted that has been corrupted by the environmental conditions imposed on it, and is the bigger challenge...
In this paper some methods of ultrasonic signals energy estimation are presented. The origin of this study is a target strength and distance estimation using air coupled ultrasound sensors applied in ie. proximity sensors. In the pulse echo mode based systems the echo detection is based on signal threshold signal estimation. The signal threshold is associated with the signal energy, what implies incorporation...
A model-independent method of the range localization for a moving source using a single receiver is derived. The Demon (detection of envelope and modulation on noise) spectrum demodulated from the broadband noise of the vessel is obtained by the absolute low pass demodulation technology. A relationship between the range interval and the difference between the acoustic field at two different ranges...
Underwater acoustic source localization has attracted wide interests, and the source depth estimation is more difficult than that of source range and bearing. The performance of Matched Field Processing (MFP) degrades greatly under environment parameter mismatches, which makes it limited in practice. Varieties of robust methods have been proposed to relieve the mismatch problems. T. C. Yang proposed...
The determining problem of several fracton mixture srtucture of materials grinding in the gas jet mill is considered. The problem is solved by comparing the standard deviation of the standart power spectral density of acoustics signals of individual fractions and of the mixture ones.
Plane-wave imaging plays a highly significant role o wing to the special demand for high frame rate, however, its po or image quality hinders its application in ultrasound industrie s. Many scholars have attempted to give a wide variety of soluti ons to improve the image quality, however, each of them has li mitations or compromises. In this study, we improve the spatio -temporally smoothed factor...
In recent years, accurate location and characterization of damage has motivated the engineering community to develop several damage identification techniques. Many of the nondestructive evaluations and structural health monitoring techniques are based on the analysis of huge amount of data collected from acousto-ultrasonic sensors. Such analysis is typically a very time-consuming process. Therefore,...
In vivo estimation of attenuation coefficients is useful because of its potential for tissue characterization and relevance in accurate backscatter coefficient estimation. However, current methods based on spectral analysis for ultrasonic attenuation estimation suffer from a severe trade-off between estimation precision and spatial resolution. Recently, the regularized spectral log difference (RSLD)...
The Reference Phantom Method can be used to quantify acoustic properties of tissue by compensating for system effects using the average power spectrum from a well-characterized homogeneous medium. Widespread clinical application of the Reference Phantom Method is hindered by the need to scan the reference phantom using the same transducer, system, and system settings as used for scanning the tissue...
Pressure measurements within the chambers of the heart yield critical information for diagnosis and management of cardiac patients (∼92 million Americans), but cardiac catheterization procedure is invasive and expensive. Subharmonic aided pressure estimation (SHAPE) may be able to estimate intra-cardiac pressures noninvasively, if the optimum incident acoustic output (IAO) for SHAPE can be established...
Subharmonic aided pressure estimation (SHAPE) is based on the inverse relationship between the subharmonic amplitude of contrast microbubbles and the ambient pressure. A noninvasive ultrasound based pressure estimation procedure would be a major development in the diagnosis of portal hypertension and less invasive than the current hepatic venous pressure gradient (HVPG) measurement. The hypothesis...
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