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 33 for “"STFT"”.
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Differential DSP: An audio toolbox for end-to-end ml
The short-time Fourier transform (STFT) has been a staple of signal processing, often being the first step for many audio tasks. A very familiar process when using the STFT is the search for the best STFT parameters, as they often have significant side effects if chosen poorly. These parameters are …
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Time-Frequency Analysis and Filtering based on the Short-Time Fourier Transform
… is the short-time Fourier transform (STFT), which remains to <br/>date the most widely used method for the analysis of signals whose spectral content varies with time. Recent application examples of the STFT and its variants – e.g. the squared magnitude of the STFT known as the …
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Analysis and filtering of time-varying signals
… (PWD), the Short-time Fourier transform (STFT) and the optimally smoothed Wigner distribution (OSWD) used in analyzing STV signals are analyzed and compared. The OSWD is shown to perform satisfactorily even if the signals are amplitude modulated. The OSWD is shown to yield the exact …
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Time-Frequency Localisation of Distributed Brillouin Optical Time Domain Reflectometry
… Optical Time-Domain Reflectometry (STFT-BOTDR), which implements STFT over the full frequency spectrum to measure the distributed temperature and strain along the optic fibre, is applied so that the conventional frequency sweeping method can be replaced for high resolution and fast …
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Statistical Model Based Multi-Microphone Speech Processing: Toward Overcoming Mismatch Problem
… performed in the short-time Fourier transform (STFT) domain, since the atomic speech information can be meaningfully represented with a series of 10 to 30 ms short frames. Convolution in the time domain is formulated as filtering via a feed-forward network in the STFT domain, and is shown to be …
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Mixed-Signal Architectures for Spectrum Sensing
… is based on the short-time Fourier transform (STFT). The architecture consists of a folded double balanced mixer with capacitive loads that implements current-domain windowing in the first stage while downconversion mixing and integration is implemented in the second stage. A load capacitor …
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Bayesian algorithms for speech enhancement
… the clean speech Short Time Fourier Transform (STFT) coefficients. The algorithms are derived from the Bayesian theory of estimation and can be grouped according to i) the STFT representation they estimate ii) the estimator they apply and iii) the speech prior density they assume. Apart from the …
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End-to-end non-negative auto-encoders: a deep neural alternative to non-negative audio modeling
… applications, the short-time fourier transform~(STFT) is used as a universal first step and we design algorithms and neural networks to operate on the magnitude spectrograms. We interpret the sequence of steps involved in computing the STFT as additional neural network layers. This enables us to …
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A verification experiment of the second formant transition feature as a perceptual cue in natural speech
… release. Short Time Fourier Transform (STFT) modifications are made to consonant-vowel (CV) non-sense syllables to remove each of the tested acoustic features. Changes in listener response error are reported. An ANalysis Of VAriance (ANOVA)is used to determine the perceptual significance …
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Modeling, Designing and Applying Machine Learning Algorithms for Driver Drowsiness Detection
… uses both wavelet and short Fourier transform (STFT). The algorithm extracts and selects the desired features. Then, the system applies both the support vector machine (SVM) and K- nearest neighbor (KNN) method. This achieves an accuracy of 80% or higher. In this research, the accuracy output …
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Surface electromyography based speech recognition system and development toolkit
… feature sets, the short-time Fourier transform (STFT), the dual-tree complex wavelet transform (DTCWT), a non-causal time-domain based (E4-NC), and a causal version of E4-NC (E4-C) were implemented. Classification was performed using a hidden Markov model (HMM). The system implemented was able to …
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Relationship between the autonomic nervous system and the recovering heart post exercise using heart rate variability
… (CWT) and the Short Time Fourier Transform (STFT). A moderate relationship (R^2=0.5164) exists between the HF and the rate of recovery. Changes in the ANS throughout the experiment indicated a drop in both the LF and HF (where LF represents a mixture of sympathetic and parasympathetic …
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Analyse optischer Heterodynsignale zur dynamischen Charakterisierung von Diodenlasern
… sich ein „Gefensterte Fouriertransformation“ (STFT) an, die sich außerdem relativ einfach in moderne Signalprozessortechnik implementieren lässt. Sie erweist sich als sehr robust und für die hier erforderliche Analyse von Heterodynsignalen als ausreichend. Mit der Festlegung des Analysefensters …
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Wavelet Scattering Transforms Applied to Whale Vocalisations
… utilise the short-time Fourier transform (STFT), for which the continuous wavelet transform (CWT) serves as a suitable alternative. As an additional contribution, we improve upon the spectral entropy (SE) detector, which is known to be superior in terms of signal detection compared to …
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An approach for the separation of voices in composite musical signals
… signals, based on short-time Fourier transform (STFT) methods. The procedure is evaluated via resynthesis of a ""desired"" signal from the composite analysis and tracking data. Other applications include signal restoration, digital editing and splicing, musique concrete, noise reduction, and …
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Radar-Based Multi-Target Classification Using Deep Learning
… using the Short-time Fourier transform (STFT) algorithm. Spectrograms of the following classes were utilised in classification: one human walking, two humans walking, one human running, moving vehicles, a swinging sphere and clutter/noise. A seven-layer residual network was proposed, …
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Instrument Timbres and Pitch Estimation in Polyphonic Music
… an estimate of the magnitude spectrum via STFT and models the harmonic structure of each pitch contained in the magnitude spectrum with Gaussian density mixtures, whose parameters are subsequently estimated via an Expectation-Maximization (EM) algorithm. Heuristics for EM initialization are …
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Single-Microphone Speech Dereverberation: Modulation Domain Processing and Quality Assessment
… masking in the short time Fourier transform (STFT) domain, preserving only those spectral components less corrupted by reverberation. The experiment results show that single-channel ITFM outperforms four existing multi-channel dereverberation methods and suggest that large potential …
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Micro-doppler classification of humans and animals using FMCW radar
… and using Short-Time Fourier Transform (STFT) for spectrogram generation were applied. Principal Component Analysis (PCA) was employed as the method for data reduction. The dataset was subsequently classified and evaluated across various target class configurations, comparing both the …
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Wavelets Based on Second Order Linear Time Invariant Systems, Theory and Applications
… results than the Short-time Fourier Transform (STFT) and the other harmonic wavelets used in time-frequency analysis. The modal decomposition is applied for modal parameters identification, and the properties of the Laplace and the SOULTI wavelet transforms allows analytical and accurate …
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