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 49 for “"Signal attenuation"”.
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Rock differentiation using microwave irradiation
… to implement. A study of low power microwave attenuation and reflection measurements was undertaken. Reflection measurements were found to be impractical due to the similar amounts of reflected signal from the different rock types. Microwave signal attenuation through rock samples was studied …
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A Novel Intrabody Communication Transceiver for Biomedical Applications
… studies have shown a degradation of transmission signal for IBC between limb segments, these degradations have yet to be quantified with respect to relative limb positions. The current thesis investigates the influence of human movement on signal attenuation during IBC considering limb joint …
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Particle-Based Triboelectric Vibration Sensor for Speech Recognition and Remote Machine Condition Monitoring
… and overcome electromagnetic interference and signal attenuation issues during long-distance transmission. To address these challenges, I introduce a high-bandwidth, self-powered triboelectric particle-surface vibration sensor. The sensor comprises a flat round capsule filled with dielectric …
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An Analysis of 12 GHz low angle radiometric data
… abilities to measure sky noise temperature. Attenuation caused by atmospheric particles (rain, ice, oxygen, etc.) can be predicted from the sky noise temperature. Three years of data (1979-1981) were available for data reduction and analysis. From this data a model is developed to predict …
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Channel prediction and adaptation over satellite channels with weather-induced impairments
… (above 10 GHz) to have significant link attenuation. Usually extra link margins are used to assure link availability. These margins cause inefficient use of precious satellite and terminal power, and unnecessarily limit data throughputs. Efficiency improvements using channel prediction …
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Application of hyperspectral imaging in pharmaceutical analysis
… analysis was used to separate the spectral signals. The near infrared (nIR) was shown to be the most effective wavelength range at separating signals due to an increased number of peaks for comparative analysis. The examination of the dissolution of paracetamol tablets produced by several …
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Indoor positioning using modulated echo radio localization instrument (MERLIN)
… sight with the GPS satellites as well as drastic signal attenuation due to buildings. This calls for a new technology to address this field, thus making indoor positioning a focus of research and development in the past decade. This thesis discusses a positioning system called MERLIN, which is …
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Mechanical performance of optical fibre cable: A theoretical and practical analysis to establish advanced design rules for optical fibre cables.
… company. This research has explained associated signal attenuation phenomena and has shown how customer requirements may be successfully achieved through the logical application of proven physical principles.
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Macromodeling and demonstration of the LT6600 amplifier and lowpass filter
… filtering options and provided 4th-order signal attenuation with only 14 nV/[square root]Hz of voltage noise spectral density.
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Towards Autonomous Localization of an Underwater Drone
… ineffective in underwater environments due to signal attenuation. Autonomous underwater vehicles utilize one or more of the following approaches for successful localization and navigation: inertial/dead-reckoning, acoustic signals, and geophysical data. This thesis examines autonomous …
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Process and design techniques for low loss integrated silicon photonics
… (waveguides) offer high data bandwidths with low signal attenuation and virtually zero heat dissipation. Strategic replacement of RC speed-limited electronic interconnects with photonic interconnects is a logical step to improving data processing performance in future microprocessors. Integration …
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Complex muscle architecture described with diffusion weighted MRI
… by determining direction-specific variations of signal attenuation. Gradients are applied in a set of directions, intensities, and durations and the attenuation data combined to form an approximation of fiber alignment within each voxel. The main original contributions of this work are the …
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High-Dimensional Quantum Information: From Sensing to Underwater Quantum Communication
… characterized by large optical turbulence and signal attenuation. These two challenges are of significant interest underwater communication channels. The detection of high-dimensional states also provides a great challenge for efficiently performing quantum information tasks as the …
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Effects of diversity routing on TCP performance in networks with stochastic channels
… fading effects in wireless networks, or due to signal attenuation by changing weather conditions and turbulence in satellite channels. In this thesis, we study the effects of a diversity routing strategy on TCP performance in networks with stochastic links. This strategy allows each data sender …
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DC powerline communication system using a transmission line transformer for high degree of freedom applications
… are analyzed, and the overall line impedance and signal attenuation are evaluated as the number of nodes goes to infinity. A prototype DC powerline communication system is then designed, built, and tested. The serial windings and special resonance characteristics of TLT coupled with a capacitor …
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Statistical correlation as a tool in propagation studies
… involves correlating dB values of the satellite signal attenuation and polarization isolation with dBZ values of radar backscatter from each of 128 range gates. In it, Pearson product moment correlation coefficients are calculated for attenuation and backscatter and for isolation and backscatter. …
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The Three-Dimensional Turbulent Boundary Layer on a Rotating Disk
… main associated errors were the disk flatness, signal attenuation caused by spatial and temporal resolution challenges and hot-wire conduction close to the wall. The encountered challenges and steps taken to address these are discussed in detail.</p>
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Total power radiometers at 12, 20 and 30 GHz used in the OLYMPUS experiment at Virginia Tech
… The experiment is set up to measure the received signal strength of beacons at 12.502, 19.770 and 29.656 GHz on board the OL YMPUS satellite in order to gather space-earth propagation statistics for a period of one year. The radiometers are used to set the clear sky reference levels for the beacon …
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Terrestrial radio wave propagation at millimeter-wave frequencies
… multipath dispersion, short-term variation and signal attenuation under different weather conditions. A design technique is developed to estimate multipath characteristics based on antenna patterns and site-specific information. Finally, indoor propagation channels at 60+AH4AXA-mbox{GHz} are …
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Analyzing Bit Error Rate using Universal Software Radio Peripheral (USRP) Software Defined Radio in Indoor and Outdoor Environments
… (USRP), with the time synchronization and signal processing occurring in the GNU Radio environment on the Linux platform. The GNU radio allows us to modify several channel parameters to test the behavior of the wireless channel in the real time environment. In an indoor environment, radios …
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