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Full-Text Articles in Engineering

Blind Ldpc Encoder Identification, Tian Xia Jan 2013

Blind Ldpc Encoder Identification, Tian Xia

LSU Master's Theses

Nowadays, adaptive modulation and coding (AMC) techniques can facilitate flexible strategies subject to dynamic channel quality. The AMC transceivers select the most suitable coding and modulation mechanisms subject to the acquired channel information. Meanwhile, a control channel or a preamble is usually required to synchronously coordinate such changes between transmitters and receivers. On the other hand, low-density parity-check (LDPC) codes become more and more popular in recent years due to their promising capacity-approaching property. The broad range of variations in code rates and codeword lengths for LDPC codes makes them ideal candidates for future AMC transceivers. The blind encoder identification …


Study On Effects Of Supply Voltage Asymmetry And Distortion On Induction Machine, Prashanna Dev Bhattarai Jan 2013

Study On Effects Of Supply Voltage Asymmetry And Distortion On Induction Machine, Prashanna Dev Bhattarai

LSU Master's Theses

Performance of induction motor supplied with asymmetrical and nonsinusoidal supply voltages is studied in this thesis. Theory of induction motor is first presented for sinusoidal symmetrical supply voltages. Equations for the torque, losses, currents and efficiency are derived. Appropriate changes are made to apply this theory to induction motors operating at nonsinusoidal and asymmetrical supply voltages. Single phase equivalent circuit of the induction motor is presented for both asymmetrical and nonsinusoidal supply voltages. The equations governing operating characteristics are presented. Machine torque, losses, current and efficiency for asymmetrical and nonsinusoidal supply voltages are compared with the same for sinusoidal symmetrical …


Performance And Power Comparisons Between Fermi And Cypress Gpus, Ying Zhang Jan 2013

Performance And Power Comparisons Between Fermi And Cypress Gpus, Ying Zhang

LSU Master's Theses

In recent years, modern graphics processing units have been widely adopted in high performance computing areas to solve large scale computation problems. The leading GPU manufacturers Nvidia and AMD have introduced series of products to the market. While sharing many similar design concepts, GPUs from these two manufacturers differ in several aspects on processor cores and the memory subsystem. In this work, we conduct a comprehensive study to characterize and compare the architectural features of Nvidia’s Fermi and AMD’s Cypress GPUs. We first investigate the performance and power consumptions of an AMD Cypress GPU. By employing a rigorous statistical model …


Discrete Time Modeling And Control Of Dc/Dc Switching Converter For Solar Energy Systems, Shaghayegh Kazemlou Jan 2013

Discrete Time Modeling And Control Of Dc/Dc Switching Converter For Solar Energy Systems, Shaghayegh Kazemlou

LSU Master's Theses

Distributed generation networks including micro grids benefit from solar cells that are controlled by dc-dc converters. In this research a nonlinear discrete-time model for a buck converter tied to a solar system is derived with unknown internal dynamics. Then, adaptive neural network (NN) controller is employed to enhance stability of dc-dc converter connected to grid-tie inverter (GTI) in the presence of power system disturbances. The NN weights are tuned online by using a novel update law. By using Lyapunov techniques, all signals can be shown to be uniformly ultimately bounded (UUB). In addition, the interaction of the converter with the …


Learning And Identification Of Wireless Network Internode Dynamics Using Software Defined Radio, Benjamin Elliott Carroll Jan 2013

Learning And Identification Of Wireless Network Internode Dynamics Using Software Defined Radio, Benjamin Elliott Carroll

LSU Master's Theses

The recently developed paradigm of cognitive radio wireless devices has been developed with the goal of achieving more customizable and efficient spectrum utilization of commonly used wireless frequency bands. The primary focus of such spectrum utilization approaches has been to discern occupancies and vacancies over portions of the wireless spectrum without necessarily identifying how specific radio frequency (RF) devices contribute to the temporal dynamics of these occupancy patterns within the spectrum. The aim of this thesis is to utilize a hidden semi-Markov model (HSMM) statistical analysis to infer the individual occupancy patterns of specific users from wireless RF observation traces. …


Gpu Acceleration Of The Variational Monte Carlo Method For Many Body Physics, Kaushik Ragavan Rajagopalan Jan 2013

Gpu Acceleration Of The Variational Monte Carlo Method For Many Body Physics, Kaushik Ragavan Rajagopalan

LSU Master's Theses

High-Performance computing is one of the major areas making inroads into the future for large-scale simulation. Applications such as 3D nuclear test, Molecular Dynamics, and Quantum Monte Carlo simulations are now developed on supercomputers using the latest computing technologies. As per the TOP500 supercomputers rating, most of today‘s supercomputers are now heterogeneous: with massively parallel Graphics Processing Units (GPU) equipped with Multi-core CPU(s) to increase the computational capacity. The Variational Monte Carlo(VMC) method is used in the Many Body Physics to study the ground state properties of a system. The wavefunction depends on some variational parameters, which contain the physics …


Fault Observability In Distributed Power System, Hamidreza Nazaripouya Jan 2013

Fault Observability In Distributed Power System, Hamidreza Nazaripouya

LSU Master's Theses

Fault observability as well as fault location algorithms in distributed power system are studied in this thesis. The importance of finding the fault location in a distribution system with the purpose of increasing reliability and decreasing the maintenance time and cost is discussed. Then, different existing fault location algorithms and approaches in the literature are introduced and compared. Subsequently, a new strategy to achieve fault observability of power systems while aiming minimum required number of Phasor Measurement Units (PMUs) in the network is proposed. The method exploits the nodal voltage and mesh current analyses where the impedance and admittance matrices …


Yield Detection For Non-Destructive Testing Using Ultrasonic Signal Processing, Bharath Murali Thekkedath Jan 2013

Yield Detection For Non-Destructive Testing Using Ultrasonic Signal Processing, Bharath Murali Thekkedath

LSU Master's Theses

Structural health monitoring (SHM) is a very important field for many engineering disciplines. SHM deals with the monitoring of material structures periodically for assessing the lifetimes of the structures. There are various techniques for SHM. Non-destructive testing (NDT) is one of the most popular SHM tools to monitor structures. It demonstrates the indispensable advantage of providing structural health assessment without the need of intrusion. In this thesis, a new NDT tool for yield detection using ultrasonic signal processing is investigated. In this work, for the study of yield detection, steel specimen samples have been acquired, which were obtained from the …