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 83 for “"correlator"”.
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Design of a real time digital image correlator
… presents the design of a real time digital image correlator circuit The circuit accepts images in real time from two video sources, with one video source serving as a reference with which images from the second video source are compared. The proposed circuit extracts a reference window from the …
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Direct position tracking in GPS using vector correlator
… for direct position tracking using the vector correlator sum. This technique of maximizing the vector correlation sum proves to be beneficial in certain kinds of multipath environments. Further, the tracking loop architecture is validated using experiments with a software receiver.
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Correlator for a Basis-Space Architecture Ultra-Wideband Receiver
Ultra Wideband (UWB) signals have great potential for high data transmission and precise location. However, their wide bandwidth and low signal to noise levels make UWB receiver design via traditional methods difficult. New receiver architectures have been proposed that rely on the correlation of …
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The investigation of correlator systems utilizing object and frequency space filters
… development of a rotationally invariant optical correlator.<br/><br/>Optical correlation systems are investigated for the purpose of high speed, high discriminant and distortion invariant pattern recognition. A photorefractive joint transform correlator (JTC) using Bismuth Silicon Oxide (BSO) as …
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Robust Speech Filter And Voice Encoder Parameter Estimation using the Phase-Phase Correlator
… robust estimator of correlation, the Phase-Phase correlator that is able to cope with impulsive noise. Utilizing this correlator, we develop a Robust Mixed Excitation Linear Prediction encoder that provides improved audio quality for voiced, unvoiced, and transition speech segments. This is …
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Wideband Propagation Measurement Results, Simulation Models, and Processing Techniques for a Sliding Correlator Measurement System
… and simulation models for a sliding correlator measurement system. The sliding correlator technique is explained in detail and large-scale measurement survey is presented. Techniques for statistically quantifying the characteristics of propagation using the sliding correlator …
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Simulation of a binary phase shift keyed receiver with an IF correlator for position location
… a binary phase shift keyed receiver with an IF correlator in a position location application. The feasibility study is done using mathematical simulation. Traditionally the correlator, in a binary phase shift keyed receiver, is placed after the data demodulator. It correlates the incoming …
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Three-Point Correlator and Pion Form Factor in Quantum Chromodynamics: Methods of Calculation for Two-Loop Spectral Density
<p>The methods are developed of two-loop calculation of spectral density for the 3-point correlation function of an electromagnetic current and two axial currents which are the basis of the pion form factor analysis within the framework of QCD sum rules and local quark-hadron duality approach. The …
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Design and Implementation of an Ultrabroadband Millimeter-Wavelength Vector Sliding Correlator Channel Sounder and In-Building Multipath Measurements at 2.5 & 60 GHz
Over the past decade, the market for wireless service has grown at an unprecedented rate. The industry has grown from cellular phones and pagers to broadband and ultra-broadband (also called ultra-wideband) wireless services that can provide voice, data, and full-motion video in real time. This …
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Ultra-wideband Spread Spectrum Communications using Software Defined Radio and Surface Acoustic Wave Correlators
… system using a surface acoustic wave (SAW) correlator receiver with orthogonal frequency coding and software defined radio (SDR) base station transmitter. Orthogonal frequency coding (OFC) and pseudorandom noise (PN) coding provide a means for spreading of the UWB data. The use of orthogonal …
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Accelerating software radio astronomy FX correlation with GPU and FPGA co-processors
… sections of a frequency domain radio astronomy correlator using dedicated co-processors. Two co-processor implementations were made independently with one using reconfigurable hardware (Xilinx Virtex 4LXlOO) and the other uses a graphics processor (Nvidia 9800GT). The objective of a radio …
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Optical information processing using photorefractive BSO
… are also presented of various optical correlators using BSO. These include the optical intensity correlator. The unique properties of the intensity correlator are stressed by practical demonstration. Specifically, the relative intolerance of the intensity correlator (compared with …
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Bayesian Modelling of Galaxy Clusters with the Arcminute Microkelvin Imager
… in the cluster field. In 2015, AMI’s analogue correlator was upgraded to a digital correlator, which was intended to improve the dynamic range and to reduce artefacts in the maps, particularly in the presence of bright sources. In this thesis I present cluster observation and analysis with the …
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Properties and processing applications of photoreactive BSO
A joint transform correlator (JTC) using photorefractive Bismuth Silicon Oxide (BSO) as a nonlinear recording medium, and a liquid crystal television (LCTV) as a spatial light modulator (SLM) is implemented. The physical basis of the processes involved in the photoreffactive recording is studied, …
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Modelling of bio-inspired vision system for velocity estimation.
… Horridge template model and (ii) the Reichardt correlator model. Various extensions and enhancements of these models are implemented with the goal of achieving robust velocity measurements. The template model is one of the prominant models of motion detection, which was proposed by Horridge in …
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Real-time optical intensity correlation using photorefractive BSO
… recording medium in the real-time intensity correlator. To improve the dynamic holographic recording, a moving grating technique is adopted. The nonlinear effects of moving gratings at large fringe modulation are experimentally investigated, and are compared with numerical …
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Bandpass filters for unconstrained target recognition and their implementation in coherent optical correlators
An up-dateable correlator is simulated which is based on the non-degenerate four wave mixing (NDFWM) interaction in the photorefractive material bismuth silicon oxide (Bi12SiO20). Specifically, it is shown that variable bandpass filters can be implemented directly in the correlator by adjusting the …
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Light Quark Masses from QCD Finite Energy Sum Rules
… energy plane, and Cauchy’s theorem for the correlator of axial-vector divergences. This procedure relates a QCD expression containing the quark masses, with an hadronic expression in terms of known hadron masses, couplings, and lifetimes/widths. Thus, the quark masses become a function of …
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Interferometric Methods
… which is pushing the bounds of current FX correlator technology with $\mathbb{O}(n^2)$ scaling, where $n$ is the number of antennas. The design proposals for these instruments include a dense core of antennas, necessitating advances in imaging methods for these very dense cores versus more …
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Dark signalling and code division multiple access in an optical fibre LAN with a bus topology
… of optical CDMA schemes using incoherent correlators is the effect of optical beating due to the presence of multiple incoherent optical signals at the receiver photodiode. The network proposed and analysed in this thesis avoids beating between multiple optical fields because it only uses …
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