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 63 for “"radio waves"”.
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Stratospheric scattering of radio waves and the Jicamarca radio telescope
… and mechanisms of stratospheric scattering of radio waves is discussed. The equipment and procedures used in previous experiments at the Jicamarca Radio Observatory are examined in detail, and are found to require modification in some cases. The theory of phased arrays is presented, and the …
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An Investigation of the Direction of Arrival of Radio Waves
Made available in DSpace on 2015-05-12T17:06:16Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 0009032.PDF: 6481336 bytes, checksum: 5e196cb41203e30cb9d3816a72b98fbb (MD5) Previous issue date: 1954
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Contactless Sleep and Physiological Monitoring Using Artificial Intelligence and Radio Waves
… advances in artificial intelligence (AI) and radio-frequency (RF) sensing. Our solution makes monitoring more comfortable, accessible, and affordable, while still delivering clinically meaningful insights. This thesis makes four fundamental contributions: First, we introduce a system that can …
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A Study of Radio Waves Scattered From Field-Aligned and Other Ionosphericirregularities
Made available in DSpace on 2014-12-04T21:03:23Z (GMT). No. of bitstreams: 1 6104403.pdf: 5680087 bytes, checksum: 440c82e3176ce80945972f77984288c1 (MD5) Previous issue date: 1961
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Pulse broadening due to multipath scattering of radio waves by the interstellar medium.
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1971.
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Some Basic Problems in the Determination of the Direction of Arrival of Radio Waves
Made available in DSpace on 2014-12-04T21:03:04Z (GMT). No. of bitstreams: 1 5900521.pdf: 6605574 bytes, checksum: 3547ffaf3998eb080c0f8eb2906e0346 (MD5) Previous issue date: 1958
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A preliminary discussion of D-region height fluctuations detected by reflecting 100 KHz radio waves.
Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Geology and Geophysics, 1968.
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A Study and Modelling of the Propagation Effects of Vegetation on Radio Waves at Centimetre-Wavelength Frequencies
… in and more diverse applications of microwave radio communications, the probability of a signal propagating through a medium of vegetation is increased. As a direct result of this demand for microwave communication systems, knowledge is required of the effects of vegetation media on the …
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The Validity of Using a Geographic Information System's Viewshed Function as a Predictor for the Reception of Line-of-Sight Radio Waves
… industry, this function has been used to model radio wave coverages and to site transceiver towers for cellular phones. However, there are errors involved with this function and, without the requisite data, it cannot account for building heights that may affect visibility in urban areas. This …
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Automatic Sleep Assessment from Nocturnal Breathing and Its Applications for Contactless Monitoring
… on-body sensors) simply by analyzing the radio waves bouncing off people’s bodies while they sleep is quite powerful. Such a capability would allow for longitudinal data collection in patients’ homes, informing our understanding of sleep and its interaction with various diseases and their …
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Implementation of the Transmitting Functionality on the TIGER-3 FPGA-based Transceiver Platform
High Frequency (HF) radio waves (3-30 MHz) are commonly used in long-range communication applications or in radars that require long-range detection capabilities. This is due to the refraction of HF radio waves, where the transmitted wave bends back towards to the Earth. HF radio waves can …
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Forecasting the nighttime evolution of radio wave ducting in complex terrain using the MM5 numerical weather model
… conditions that cause anomalous propagation of radio waves. Providing early warning about where and when such conditions will develop would be particularly useful for military communications. To test mesoscale models' ability to provide such early warning, the Pennsylvania State University I …
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Examining Innovation Translation of RFID Technology in Australian Hospitals through a Lens Informed by Actor-Network Theory
… in large hospitals is dynamic and multifaceted. Radio frequency identification (RFID) is a rapidly evolving technology that uses radio waves for data collection and transfer, without human involvement. As an acronym, RFID is used broadly for categorising technologies that use radio waves to …
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Calibration of Jicamarca radar using F-region incoherent scatter for measurements of D-region backscatter RCS
… radar echoes observed at the Jicamarca Radio Observatory in Perú. Radar system calibration is accomplished by simulating the propagation of transmitted and backscattered radio waves through the ionosphere and comparing the simulated power returns to the measurements. The forward model …
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Effects of the troposphere upon radio communications and implications for weather measurement
… to use observations of Very High Frequency (VHF) radio wave propagation to estimate the refractive index of air over a propagation path and subsequently the pressure, temperature, and water vapour. This can be accomplished by transmitting a known signal from one spatial location to another, and …
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Artificial heating of the lower ionosphere
… at an altitude of 80 km. Energy from the radio wave is deposited in the ionosphere as a result of collisions of the electrons with the neutral molecules. Cross-modulation experiments (performed elsewhere) have gained information on electron number density and collision frequency between 60 …
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High Frequency Radio Wave Transionospheric Propagation Polarization Studies from the RRI-SuperDARN Experiment
… One of the 8 instruments it carries is the Radio Receiver Instrument (RRI) which is a passive cross-dipole radio observation instrument. The RRI detects incoming HF (High Frequency) radio waves and measures the polarization information (such as orientation angle and ellipticity angle) of the …
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Acoustic/Gravity Wave Phenomena in Wide-Field Imaging: From Data Analysis to a Modeling Framework for Observability in the Mlt Region and Beyond
<p>Acoustic waves, gravity waves, and larger-scale tidal and planetary waves are significant drivers of the atmosphere’s dynamics and of the local and global circulation that have direct and indirect impacts on our weather and climate. Their measurements and characterization are fundamental …
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A Grid based Indoor Radiolocation Technique Based on Spatially Coherent Path Loss Model
This thesis presents a grid-based indoor radiolocation technique based on a Spatially Coherent Path Loss Model (SCPL). SCPL is a path loss model which characterizes the radio wave propagation in an environment by solely using Received Signal Strength (RSS) fingerprints. The propagation of the radio …
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