Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 108 for “"Acoustic Signals"”.
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DIGITAL ANALYSIS OF CARDIAC ACOUSTIC SIGNALS IN CHILDREN
DIGITAL ANALYSIS OF CARDIAC ACOUSTIC SIGNALS IN CHILDREN Milad El-Segaier, MD Division of Paediatric Cardiology, Department of Paediatrics, Lund University Hospital, Lund, Sweden SUMMARY Despite tremendous development in cardiac imaging, use of the stethoscope and cardiac auscultation remains the …
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Statistical and Biological Analyses of Acoustic Signals in Estrildid Finches
<p>Acoustic communication is a process that involves auditory perception and signal processing. Discrimination and recognition further require cognitive processes and supporting mechanisms in order to successfully identify and appropriately respond to signal senders. Although acoustic communication …
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Synergistic Combination of Microwaves and Acoustic Signals: Towards Improved Breast Imaging
… resonance imaging (MRI). The ultrasound (US) signals with their short wavelength, low loss and small footprint may also provide this opportunity. The aim of this work is to investigate the possibility of extracting prior information from US signals and integrating this information into …
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Statistical Spectral Parameter Estimation of Acoustic Signals with Applications to Byzantine Music
<p>Digitized acoustical signals of Byzantine music performed by Iakovos Nafpliotis are used to extract the fundamental frequency of each note of the diatonic scale. These empirical results are then contrasted to the theoretical suggestions and previous empirical findings. Several parametric and …
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Maintaining contact : design and use of acoustic signals in killer whales, Orcinus orca
… thesis presents data on the structure and use of acoustic signals produced by free-ranging resident killer whales. The analysis focuses on signal features that might be useful for animals to maintain contact and coordinate activities with preferred associates, including: distinctiveness by group …
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Interaction of task-related and acoustic signals in single neurons of monkey auditory cortex
Contains fulltext : 450811.pdf (Publisher’s version ) (Open Access)
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Investigation on Mt. Etna dynamics by seismic and acoustic signals (August 2007-December 2010)
… system, and define the source-mechanism of acoustic events at Mt. Etna, infrasound signals-continuously recorded by Istituto Nazionale di Geofisica and Vulcanologia- were analyzed in this thesis, jointly with some seismic signals. In particular, we focused on the period comprised between …
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Machine-Learning-Based Non-Destructive Evaluation of Refractory Anchor Welds via Analysis of Percussion-Induced Acoustic Signals
… ends of these anchors. The resulting audio signals were recorded and transformed into Mel-Frequency Cepstral Coefficients (MFCCs). These MFCCs served as input features for multiple machine learning models including supervised and unsupervised models. The supervised models used were support …
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The statistics of finite bandwidth, modulated acoustic signals propagated to long ranges in the ocean, including multiple source effects.
Thesis. 1979. Ph.D.--Massachusetts Institute of Technology. Dept. of Ocean Engineering.
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Acoustic Signals of Closely Related Bird Species Differ More in Sympatry Than in Allopatry - But Not If They Are Learned
Closely related species often have similar mating signals because of their shared recent ancestry, which can affect their reproductive isolation and ability to live together when they overlap in range. Similar mating signals can result in costs of co-occurrence (e.g., maladaptive hybridization, …
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The effects of stress hormones on preferences for acoustic signals in female green treefrogs (Hyla cinerea) and barking treefrogs (Hyla gratiosa)
… for call rate and/or call duration - two acoustic features that are highly variable and characteristically under directional selection via mate choice by females. In <italic>H. cinerea<italic>, the probability of choosing male advertisement calls broadcast at high rates in dual speaker …
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Cultural evolution in Rufous-and-white Wrens (Thryophilus rufalbus): Insights from acoustic and genetic analyses
Acoustic signals play an important role in the evolutionary process. Studying variation in acoustic signals and the evolutionary forces that act on acoustic evolution will help to clarify the role that acoustic divergence plays during speciation. The acoustic signals of birds have been well …
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The effect of attenuation from fish on long-range active and passive acoustic sensing in the ocean
Attenuation from fish can reduce the intensity of acoustic signals and significantly decrease detection range for long-range active and passive sensing in the ocean. This makes it important to understand the relevant mechanisms and accurately predict attenuation from fish in underwater acoustic …
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The Effect of Attenuation from Fish on Long-Range Active and Passive Acoustic Sensing in the Ocean
Attenuation from fish can reduce the intensity of acoustic signals and significantly decrease detection range for long-range active and passive sensing in the ocean. This makes it important to understand the relevant mechanisms and accurately predict attenuation from fish in underwater acoustic …
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Modeling wireless acoustic power transmission systems
… prevents penetration of electromagnetic energy, acoustic wave transmission is often used for data communications and could be a viable option for wireless power transfer. Such a power transfer system design would need to incorporate the behavior of the entire acoustic channel, taking into account …
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A Compact Ultrasonic Airflow Sensor for Clinical Monitoring of Pediatric Tracheostomy Patients
… is a robust method that correlates the timing of acoustic signals to velocity measurement. The compact prototype developed here can non-invasively measure all airflow into and out of a patient, so that breath interruption can easily be detected. This paper concerns technical design of the sensor, …
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Condition Classification in Underground Pipes Based on Acoustical Characteristics. Acoustical characteristics are used to classify the structural and operational conditions in underground pipes with advanced signal classification methods
… and sewer condition/defect analysis based on acoustic characteristics. Pattern recognition has been studied and used widely in many fields including: identification and authentication; medical diagnosis and musical modelling. Audio based classification and research has been mainly focusing on …
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Acoustic source localization
Many technologies rely on underwater acoustics. Most of these applications are able to denoise Gaussian noise from the surrounding, but have trouble removing impulse like noises. One source of impulse-like noise is the snapping shrimps. The acoustic signals they emit from snapping their claws …
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Maximum likelihood time-domain beamforming using simulated annealing
An algorithm is developed for underwater acoustic signal processing with an array of hydrophones. With various acoustic signals coming from different directions, the maximum likelihood approach is used to estimate the source bearings and time series. Simulated annealing is used to implement the …
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