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Full-Text Articles in Engineering
Offshore Wind Energy Study And Its Impact On South Carolina Transmission System, Tingting Wang
Offshore Wind Energy Study And Its Impact On South Carolina Transmission System, Tingting Wang
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As one of the renewable resources, wind energy is developing dramatically in last ten years. Offshore wind energy, with more stable speed and less environmental impact than onshore wind, will be the direction of large scale wind industry. Large scale wind farm penetration affects power system operation, planning and control. Studies concerning type III turbine based wind farm integration problems such as wind intermittency, harmonics, low voltage ride through capability have made great progress. However, there are few investigations concerning switching transient impacts of large scale type III turbine based offshore wind farm in transmission systems. This topic will gain …
Study On Electromagnetic Scattering Of Cylinders Buried In A Half Space With Random Rough Surfaces Of Finite/Infinite Length, Yueyang Dai
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Analysis of electromagnetic scattering of buried objects is a subject of great interest due to its practical importance in both military and civil applications, such as subsurface investigation and target detection. In reality, the earth is of layered structure of random rough interfaces, which leads to a greatly increased complexity of the analysis. However, it is necessary to incorporate the nature of random rough surface and the layered structure because they both have substantial impact on the scattered signature and hence affect the study of inverse scattering and detection of buried objects. In this dissertation, a Monte-Carlo multidomain pseudospectral time …
Encapsulated And Monolithic Resonant Structures For Laser Applications, Aaron Pung
Encapsulated And Monolithic Resonant Structures For Laser Applications, Aaron Pung
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Typically, the composition of a laser system includes a gain medium, a pump illumination source, and an external feedback cavity. This cavity consists of a highly reflective mirror and an outcoupler component. The geometry of the outcoupler can be engineered to tailor the reflected or transmitted beam's spatial and spectral distribution. Functionally, the transmitted beam profile is dependent on the laser application. Broadband reflection profiles can be obtained by utilizing a distributed Bragg reflector (DBR). A DBR device consists of multiple layers of alternating materials. Constructive interference of the reflected light off each interface between different materials produces the spectrally …
Adaptive Transmission Protocols For Wireless Communication Systems With Fountain Coding, Jason Ellis
Adaptive Transmission Protocols For Wireless Communication Systems With Fountain Coding, Jason Ellis
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We present low-complexity adaptive protocols for both unicast and multicast transmission in wireless communication systems that employ higher layer fountain codes. Our adaptive protocols respond to variations in channel conditions by adapting the modulation and channel coding of transmitted packets, and they provide efficient communication over wireless channels that experience fading, shadowing, and other time-varying propagation losses. The operation of our protocols is governed by simple receiver statistics that can be obtained during the demodulation of received packets. We present three adaptive protocols for fountain-coded unicast transmission, and compare the throughput performance of our protocols with that of fixed-rate systems, …
A Hybrid Method Of Performing Electric Power System Fault Ride-Through Evaluations On Medium Voltage Multi-Megawatt Devices, John Fox
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This dissertation explores the design and analysis of a Hybrid Method of performing electrical power system fault ride-through evaluations on multi-megawatt, medium voltage power conversion equipment. Fault ride-through evaluations on such equipment are needed in order to verify and validate full scale designs prior to being implemented in the field. Ultimately, these evaluations will help in reducing the deployment risks associated with bringing new technologies into the marketplace. This is especially true for renewable energy and utility scale energy storage systems, where a significant amount of attention in recent years has focused on their ever increasing role in power system …
Electromagnetic Scattering Of Three-Dimensional (3d) Objects Embedded In A Half Space With Random Rough Surface, Wei Liu
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ABSTRACT
This dissertation presents a Monte-Carlo multidomain pseudospectral time-domain (MPSTD) algorithm developed for the analysis of scattering from a two dimensional (2D) and three dimensional (3D) object buried below a random rough surface separating two half spaces. In the development, special attention is paid to the 3D computation domain decomposition, PML derivations, filtering technique and subdomain mapping involving the random rough surface as well as the subdomain patching along the rough surface. The Mote-Carlo MPSTD algorithm is then employed to determine the scattering of objects of various shapes and electromagnetic properties; embedded in the lower half space with different permittivity …