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 16 of 16 for “"Filterbank"”.
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Auditory-based processing of communication sounds
… the speech recognition experiments, an auditory filterbank was combined with a Gaussian fitting procedure to produce features which are invariant to changes in speaker VTL. These features were compared against standard mel-frequency cepstral coefficients (MFCCs) in a size-invariant syllable …
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Multidimensional Wavelets and Neural Networks
… of ideals, modules, Fourier analysis, filterbanks and multiresolution analyses, where the mentioned concepts are already considered in an arbitrary dimensional setting to prepare the proof of the main result. There, we show the connection between multivariate scaling functions and …
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AM-FM Analysis of Structural and Functional Magnetic Resonance Images
… the most popular AM-FM methods using different filterbank configurations that includes Gabor, Equirriple and multi-scale directional designs. We compare the performance and robustness to Gaussian noise using synthetic FM image examples. We show that the multi-dimensional quasi-local method (QLM) …
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Improving the Specificity of Medical Ultrasound Imaging Using Scattering Spectrum Matching
… example, in a uniform speckle region, almost any filterbank decomposition and compounding of the echo data results in an improved contrast ratio. For example, multiband audio signal processing is often based on the use of filterbanks with constant bandwidth B or constant quality factor Q. Such …
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AM-FM methods for image and video processing
… results than methods using a multi-scale filterbank. At low noise levels (SNR > 50dB), VS-LQP performs better when used in combination with a multi-scale filterbank. In all cases, VS-LQP outperforms the Quasi-Eigen Approximation algorithm by significant amounts (up to 20dB). New least …
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Robustness of Modified FBMC-SS Against Partial-Band Noise-Like Interference
… A modification on the existing scheme of filterbank multicarrier spread-spectrum (FBMC-SS) is proposed that pseudo-randomly maps spread data chips to different time and frequency locations within a packet. The intended effect of this is to allow the decoder to consider and notch noise-like …
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Sistemas de transmissão multiportadora aplicados em um canal acústico submarino na presença de efeito doppler
… (SNR) and bit error rate. The applicability of filterbank based transceivers with reduced redundancy in each block in underwater communication systems is also analysed. The equalization, in this case, employed a Zero Forcing solution that requires less operations. Computer simulations indicate …
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Subspace methods for portfolio design
… Then, a novel methodology to design subband/filterbank portfolios for a given empirical correlation matrix by using the theory of optimal filter banks is proposed. It is a natural extension of the celebrated eigenportfolios. Closed-form expressions for Sharpe ratios and market exposures of …
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Collective analog bioelectronic computation
… as O(N logN), or a constant-fractional-bandwidth filterbank, which scales as O (N2).
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Detecting cognitive impairment from spoken language
… to learn higher-order representations from filterbank features (AUC 0.85, spec. 81%, sens. 82%). Our speech models exhibit strong performance and are comparable to the baseline demographic model (AUC 0.85, spec. 93%, sens. 65%). Further analysis shows that our neural network model …
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Noise Robust Pitch Tracking by Subband Autocorrelation Classification
… autocorrelations of subbands from an auditory filterbank. The output of the MLP classifier is temporally smoothed to produce the pitch track by finding the Viterbi path of a Hidden Markov Model (HMM). Training on various types of noisy speech recordings leads to a great increase in performance …
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Orthogonal Frequency Division Multiplexing Modelling
… Frequency Division Multiplexing (OFDM) and Filterbank Multicarrier (FBMC). Multicarrier techniques are widely being considered for the development of the telecommunication systems such as the Long Term Evolution (LTE) networks, 5th Generation (5G) and beyond. One of the modulation strategies …
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Attributes and their potential to analyze and interpret 3D GPR data
… using a two-dimensional (2D) log-Gabor filterbank decomposition of the data volume. To extract the physical information from the dual-component data set, I employed a sliding-window principle component analysis. The combination of the geometrically derived feature angle and the …
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Design of optimal equalizers and precoders for MIMO channels
Channel equalization has been extensively studied as a method of combating ISI and ICI for high speed MIMO data communication systems. This dissertation focuses on optimal channel equalization in the presence of non-white observation noises with unknown PSD but bounded power-norm. A worst-case …
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Efficient coding of natural sounds
Es werden Methoden für eine effiziente Kodierung natürlicher Töne vorgeschlagen, die auf dem Konzept der "spärlichen Kodierung" basieren, ein Hauptmechanismus in der neurosensorischen Informationsverarbeitung. Eine verbesserte Audioqualität, insbesondere bei niedrigen Bitraten, wurde in dem …
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Stereophonic Acoustic Echo Cancellation: Theory and Implementation
… the possibilities of using joint subband filterbanks or time to frequency-domain transforms for echo cancellation and perceptual audio coding. The usage of joint filterbanks/transforms not only decreases the computational complexity of the system, it also reduces the total signal …