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 39 for “"Power Spectral Density (PSD)"”.
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Spectrum sensing based on capon power spectral density estimation
… we propose a spectrum sensing based on the Capon Power Spectral Density (PSD) estimation method. The proposed method estimates the received PSD, and uses it to identify free and busy channels. A cooperative spectrum sensing approach is also introduced. The goal is to solve the common hidden node …
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Construction of a random signal with a specific Psd and a uniform Pdf
… network with a random signal that has a specific power spectral density (PSD) and a uniform probability distribution function (PDF). Many algorithms exist for generating a random signal with a white PSD and a uniform PDF, but there exists only one algorithm for generating a random signal with a …
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Anomalous diffusion of mRNA in the cytoplasm of HeLa cells
… of their mean-squared displacement (MSD) and power spectral density (PSD). We observed non-ergodic, subdiffusive behavior, with statistics that depend on observation time, i.e., aging. Additionally, we observe stochastic switching between two mobility states with an order of magnitude …
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Communication in a Poisson field of interferers
… interference and thermal noise. We derive the power spectral density (PSD) of the cumulative interference at any location in the plane. We put forth the concept of spectral outage probability (SOP), a new characterization of the cumulative interference generated by communicating nodes in a …
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Design, Analysis And Implementation Of Orthogonal Frequency Coding In Saw Devices Used For Spread Spectrum Tags And Sensors
… enhanced processing gain and lower interrogation power spectral density (PSD). It is shown that the time ambiguity in the OFC compressed pulse is significantly reduced as compared with a single frequency tag having the same code length and additional coding can be added using a pseudo-noise (PN) …
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Laser Processing of Metals and Polymers
… spectroscopy (FTIR) and x-ray diffraction (XRD). Power spectral density (PSD) spectra computed from AFM data gives further insight into the effect of laser melting on the topography of the treated niobium.</p>
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Ultrathin silicon wafer bonding physics and applications
… new description of surface quality, the Power Spectral Density (PSD). A process for reducing surface roughness of silicon is elucidated and a model of this process is described. A method of detecting particle contamination in chemical baths and other processes using wafer bonding is …
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Design of Structural Stand for High-Precision Optics Microscopy
… random vibrational data using accelerometers and Power Spectral Density (PSD) analysis, the stand was designed to meet the VC-C curve requirement of velocities below 12.5 µm/sec. Furthermore, the stand design was optimized to avoid resonance at common vibrational signatures throughout the …
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Robust Blind Spectral Estimation in the Presence of Impulsive Noise
Robust nonparametric spectral estimation includes generating an accurate estimate of the Power Spectral Density (PSD) for a given set of data while trying to minimize the bias due to data outliers. Robust nonparametric spectral estimation is applied in the domain of electrical communications and …
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The analysis and simulation of the spectral and statistical properties of road roughness for package performance testing
… of vehicle vertical acceleration from the Power Spectral Density (PSD) estimate. The vertical vehicle response acceleration is primarily a function of vehicle suspension and speed, but is ultimately caused by fluctuations in the road surface. This thesis introduces a universal analysis and …
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Models for the study of neuronal activity during cognitive tasks
… of various connectivity patterns in cortical EEG power spectral density (PSD), and investigate the possibility to derive connectivity circuits from EEG data. To this end, two different models have been built. In the first model an individual region of interest (ROI) has been built as the parallel …
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Computational Approaches To Epilepsy: Graph Networks For Localization And Multi-Model Approach For Prediction
… an ensemble of specialized classifiers. The power and flexibility of this framework are demonstrated through two distinct feature engineering approaches. Its effectiveness was first validated using a comprehensive set of power spectral density (PSD) features, achieving a mean sensitivity of …
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Predicting Surface Scatter Using A Linear Systems Formulation Of Non-paraxial Scalar Diffraction
… scattering problem of determining surface power spectral density (PSD) curves from BRDF measurements.
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Analyzing Vibration in Omni-Wheels: A Design of Experiments Approach to Optimizing Omni-Wheel Selection
… derived from Fast Fourier Transform (FFT) and Power Spectral Density (PSD) analyses of accelerometer data. Results show that rotational speed consistently increased vibration across all wheel designs, while lateral motion (90° angle) consistently reduced vibration compared to forward motion. …
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A statistical jet-noise model based on the acoustic analogy and a RANS solution
… equations (RANS). It evaluates the jet-noise power spectral density (PSD) in the quiescent region outside the turbulent jet. It includes the following components:1. A propagation model based on the high- and low-frequency approximations of the Lilley analogy Green's function. The …
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Ultra-wideband technology for short-range wireless communication
… specific constraints. The constraints are the power spectrum density limitation under Federal Communications Commission (FCC) Part 15 rules and the spreading ratio required to achieve a specified jam resistance level. UWB capacity over AWGN channel is expressed as a function of spreading ratio …
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Structural health monitoring of bridges using wireless sensor networks
… use a Fast Fourier Transform estimate of the Power Spectral Density (PSD) associated with the response of the system. In this study it is also shown that higher order statistical estimators such as Spectral Kurtosis (SK) and Sample to Model Ratio (SMR) may be successfully employed to more …
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Exploring the Variability of Accretion Discs with Stochastic Models
… related to the break frequency in the luminosity power spectral density (PSD), providing a possible observational probe for the magnetorotational instability (MRI). I then present a new 2D (vertically integrated) stochastic model for simulating variable accretion discs, generalising the previous …
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The Influence of AR Head-Mounted Displays on Spatial Perception and Worker Response in Construction Training
… heart rate) responses, which are analyzed using Power Spectral Density (PSD), Independent Component Analysis, and regression modeling to identify hemispheric differences and misalignments between perceived safety and actual psychophysiological responses. Objective 3 advances the framework into …
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Quantitative characterisation of surface finishes on stainless steel sheet using 3D surface topography analysis
… the important features shows up dominantly on a Power Spectral Density (PSD) plot and this is used to find the correct sampling interval to accurately reconstruct the 3D surface data. The correct instrument for further measurements is then selected using a Steadman diagram. Operational details of …
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