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.
Results
Showing 1 to 20 of 44 for “"phase delay"”.
-
An investigation of factors which degrade phase accuracy in a VLF relative navigation system
… the fact that, at any given point on the earth, phase delay of a received VLF signal is highly stable and predictable. As the receiver is physically moved, phase delay changes linearly with distance from the transmitting station, so that by keeping track of the phase delay of the received signal …
-
Adolescent sleep and the circadian pacemaker
… Adolescents often exhibit a circadian phase delay in which they tend to go to bed later and wake up later compared to adults. This thesis seeks to understand the adolescent phase delay and its relationship to the circadian pacemaker, the body’s master clock. Using a dynamic circadian …
-
The properties of single crystal sapphire fibers and the polarimetric optical sensor for high temperature measurements
… The temperature coefficient of the differential phase delay between the orthogonal polarization modes has been measured to be 0.0208 rad / °C m. A resolution of 2 °C has been obtained over the measurement range of 25 °C to 800 °C. It is also observed that the PMA is strongly dependent on the …
-
The Effect of General Anaesthesia on Circadian Rhythms in Mice
… To do so, I collected data to construct a full phase response curve (PRC) for each anaesthetic agent. Animals received either a six-hour GA treatment or a 10-minutes GA treatment (control group) with isoflurane (1.5%) or sevoflurane (2.6%). 80 mice were treated with isoflurane for six hours and …
-
Street Traffic Signal Optimal Control for NEMA Controllers
… and offset. This dissertation proposed a virtual phase-link concept and developed a macroscopic model to describe the dynamics of a traffic network. The coordinated optimal splits control problem was solved using model predictive control. The outputs of the solution are the green splits that can …
-
On-chip Group and Phase Velocity Control for Classical and Quantum Optical Devices
We present group and phase velocity control for the photonic integrated circuits with an emphasis on two-dimensional photonic crystal devices in this thesis. We describe the theory, analytical and numerical designs, and experimental characterization of silicon nanophotonic devices both in classical …
-
Design and analysis of direction-of-arrival estimation systems using electrically small antenna arrays
… antenna. Next generation systems depended on phase measurements for direction-of-arrival information. With the advent of DSP-based direction fi nding, a return to amplitude-based measurements is possible. This enables direction-of-arrival estimation using arrays whose interelement phase di …
-
Integral Manifold in System Design With Application to Flexible Link Robot Control
… flexible link robots is shown to be a cause for phase delay, which is reduced by a corrective controller based on the integral manifold concept. For a class of nonlinear systems with nonlinear output, we designed a nonlinear PI controller that achieve asymptotic tracking and disturbance rejection …
-
Adaptive Beamforming Using a Microphone Array for Hands-Free Telephony
… The input is split into 6 subbands such that phase-steered beamforming would be possible. Two methods of phase-steered beamforming are compared in both narrowband and wideband scenarios, and it is shown that phase-steering the array to the desired source direction-of-arrival has about 0.3 dB …
-
Retrieval of equivalent currents by the use of an integral representation and the extinction theorem --- radome applications
… beam deflection, pattern distortion, etc. The phase shift of the field due to the transmission through the radome, i.e., the insertion phase delay, is visualized. Disturbances due to defects, not detectable in the measured near field, are correctly localized by the equivalent surface currents. …
-
Novel Segment Deformable Mirror Based Adaptive Attenuator Used In Wavelength Division Multiplexed Optical Communications Network
… shown that the total electric field and relative phase delay of each beam form a Fourier transform pair. Thus methods and properties of Fourier analysis are applicable in multi-beam interference analysis and design. Fourier transform based design is presented. Novel devices that apply such design …
-
Actin's role in signaling light-induced phase shifts in the mammalian circadian clock
… into transcriptional changes which induce a delay of clock state. This signaling pathway, mediated by glutamate, involves activation of NMDA receptors, nitric oxide synthesis, and opening of ryanodine receptors with subsequent influx of calcium from intracellular stores. Activation of this …
-
A computational and experimental study of the Drosophila larval locomotor system and its developmental critical period
… periods of nervous system development are phases of heightened plasticity during which neuronal network dynamics is adjusted through activity-regulated plasticity mechanisms. Because plasticity is elevated, these phases are also vulnerable, such that disturbances during this highly plastic …
-
Spring Forward or Fall Back? Redox State as a Determinant in Glutamate Signaling Pathways Adjusting Our Brain Clock
… in the external environment by adjusting the phase of the SCN. The phase-resetting response depends on the temporal state of the clock: during the early night, light/glutamate delays clock phase, whereas during the late night, clock phase is advanced. Key signaling elements downstream of …
-
Studies of measurement techniques for indirect chemical sensing based on fluorescence spectroscopy and applications for fibre-optic sensors
… second interrogation method, where the phase delay between an intensity modulated excitation source and the resultant fluorescence is processed to make measurements, was for the first time, fully analysed for measurement of exponential decays. When measuring fluorescence lifetimes in the …
-
Measurement of a Weak Transition Moment Using Coherent Control
… is based on a two-pathway excitation, using two phase-coherent laser fields, a fundamental field at 1079 nm and its second harmonic at 539.5 nm. The IR field induces a strong two-photon transition, while the 539.5 nm field drives a pair of weak one-photon transitions: a Stark-induced transition …
-
The measurement of oxygen uptake kinetics in children
… frequency domain in terms of amplitude ratio and phase delay over the frequency range of 2.2-8.9mHz. At each of the frequencies assessed amplitude ratio was higher in children (P<0.001) than in either of the adult groups. Phase delay was also significantly shorter in children compared to adults …
-
Fluorescence lifetime distributions in proteins
… laser excitation. The detectors are modulated phase coherently with the mode-locked laser pulses to accurately determine the phase delay and modulation of the fluorescence response. The instrument achieves 1 ps time resolution. The resolvabz""l£ty provided by the experimental data obtained with …
-
Novel Multitemporal Synthetic Aperture Radar Interferometry Algorithms and Models Applied on Managed Aquifer Recharge and Fault Creep
… stacks posed challenges like interferometric phase degradation and tropospheric phase delay. This study introduces an advanced Small Baseline Subset (SBAS) algorithm that optimizes interferometric pairs, addressing systematic errors through dyadic downsampling and Delaunay Triangulation. A …
-
Harmonic Reduction IN a Single-Switch Three-Phase Boost Rectifier With Harmonic-Injected PWM
… the harmonic reduction of a single-switch three-phase boost rectifier. The approach employs a constant duty cycle with sixth-order harmonic injection to suppress the dominant (fifth-order) harmonic in the input currents. Hence, to meet the THD<10% requirement, the rectifier voltage gain can be …
Page 1 of 3