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 10 of 10 for “"Fourier spectra"”.
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Automatic detection of periodic sources in the K2 data sets
… sources in the K2 data sets. Fast discreet Fourier transformations are used to compute the Fourier spectra of the targets and two different detection algorithms for identifying significant signals are used. The first technique searches through the DFT to identify peaks that are significantly …
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Laser diffraction particle sizing : sampling and inversion
… data is compared to that of super-resolving Fourier spectra. Resolution is shown to be inversely proportional to the angular range of observations. The problem is rephrased so that the size weighted number density is sought from the intensity weighted by the scattering angle cubed. Algorithms …
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Software and hardware improvements for digital solar magnetograph system
… processing methods have been discussed and their Fourier spectra have been analyzed. After noise deduction and stray light elimination, the processed magnetograms have been proved to be much better than the original images.
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A Neural Network-Based Methodology for Generating Spectrum -Compatible Earthquake Accelerograms
… the inverse mapping directly from the response spectra to earthquake accelerograms. A two-stage approach is used. In the first stage, a replicator neural network is used as a data compression tool. The replicator neural network compresses the vector of the discrete Fourier spectra of the …
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Characterization of wave transport in non-conservative media with random and correlated disorder
… systems with singular-continuous spatial Fourier spectra. The non-periodic nature of the system makes it notoriously difficult to characterize theoretically especially in dimensions higher than one. The possibility of mapping the two-dimensional aperiodic Thue-Morse pattern of …
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Deep Learning For Microscopic Image Restoration
… the analysis of the resulting images in the Fourier spectra shows some discrepancies in the high frequency region. To address this problem, two new combinations of frequency based loss functions were proposed for denoising low SNR images. The first loss function is the combination of …
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Natural frequencies evaluation on existing reinforced concrete bridges using microtremor testing
… Sungai Simpang Kiri. By using GEOPSY software, Fourier Spectra Amplitude Ratio (FSA) analysis used for determining bridge natural frequencies and Horizontal-To-Vertical-Spectra-Ratio (HVSR) analysis for ground natural frequencies, fo. The natural frequency results for Sungai Sembrong Bridge (70 …
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Design and characterization of a smart bit for in-situ force measurement, using capacitive load cells and acoustic spectra analysis to determine rock type and tool wear in rock excavation process
… the Support-Vector machine using fast Fourier spectra magnitude of short duration samples of signal, around 0.2 seconds, performed the best. Other machine learning methods explored for classification applications in this research include multi-layer perceptron neural networks and …
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Regionally adaptable ground-motion Prediction Equations (GMPEs) for seismic hazard analysis
… the GMPEs are often derived for response spectral ordinates (e.g., spectral acceleration) of a single degree of freedom (SDOF) oscillator. The functional forms of such GMPEs are based upon the concepts borrowed from the Fourier spectral representation of ground motion. This assumption …
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Optically induced orientational transitions in nematic liquid crystals
… Hopf bifurcation and a new frequency in the time Fourier spectra of the dynamical variables appears. This regime is quasiperiodic and corresponds to a precession and nutation of the director. As the intensity increases further, this state disappears at a certain critical value where the period of …