Electrical and Computer Engineering Commons^™

Distributed Fault Detection For A Class Of Large-Scale Nonlinear Uncertain Systems, Qi Zhang

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In the distributed large-scale system, the behavior of any subsystem is not only influenced by variables belonging to it (local variables), but also by the variables in other subsystems during its interaction with neighboring subsystems. The effect of the fault in one subsystem will be quickly propagated to other subsystems due to their interconnections. Currently, most of the fault detection and diagnosis schemes are focused on centralized system which do not consider the interaction terms and can not efficiently detect the faults.

In this thesis, a distributed fault detection scheme is developed for a class of large-scale nonlinear uncertain systems …

Small-Signal Modeling Of Resonant Converters, Agasthya Ayachit

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Resonant DC-DC converters play an important role in applications that operate at high-frequencies (HF). Their advantages over those of pulse-width modulated (PWM) DC-DC converters have led to the invention of several topologies over the traditional forms of these converters. Series resonant converter is the subject of study in this thesis. By variation in the switching frequency of the transistor switches, the optimum operating points can be achieved. Hence, the steady-state frequency-domain analysis of the series resonant converter is performed. The operational and characteristic differences between the series resonant and parallel resonant and series-parallel resonant configurations are highlighted. In order to …

Fault Detection In Process Control Plants Using Principal Component Analysis, Vamshi Krishna Kandula

LSU Master's Theses

The aim of this thesis is to use a statistical method (principal component analysis) to detect a fault in a system. PCA is a dimensionality reduction technique that is used here. First the PCA algorithm was implemented on a simple two dimensional random data to reduce its dimensionality. Then the algorithm was implemented on a three dimensional data from a linear first order process and introduce some white noise later on and compare the results with that under normal operating conditions, thus determining the presence of a fault. Then data from a real time plant is considered for testing. This …

Smart Access Control System With Behavioral Profiling And Dynamic Pin Concept, Lohit Penubaku

LSU Master's Theses

Since ancient time, an access control device has been used for securing valuable properties as well as lives from threatening peoples. The most representative security device is Lock/Key. Recently, those security device technologies have been improved tremendously and provided various types of security methods. Nevertheless, these methods are not individually perfect to provide optimal security so that in recent years many such methods have been combined and used together to provide the required level of security. However, such combination can enhance security for limited number of users only but very difficult to provide scalable security with the number of users …

Communication-Constrained Feedback Stability And Multi-Agent System Consensusability In Networked Control Systems, Laurentiu Dan Marinovici

LSU Doctoral Dissertations

With the advances in wireless communication, the topic of Networked Control Systems (NCSs) has become an interesting research subject. Moreover, the advantages they offer convinced companies to implement and use data networks for remote industrial control and process automation. Data networks prove to be very efficient for controlling distributed systems, which would otherwise require complex wiring connections on large or inaccessible areas. In addition, they are easier to maintain and more cost efficient. Unfortunately, stability and performance control is always going to be affected by network and communication issues, such as band-limited channels, quantization errors, sampling, delays, packet dropouts or …

Cost And Performance Modeling Of The Mu-Decoder, Raghavendra Kongari

LSU Master's Theses

In this thesis we study the implementation details of the MU-Decoders, a recently proposed hardware module that has been theoretically shown to be superior to other methods for generating subsets of large sets. Our study confirms this advantage. Specifically, we compare the performance of implementations of the LUT-Decoder (the most common configurable decoder) to the MU-Decoder. We show that for while the LUT-Decoder is slightly better than the MU-Decoder for arbitrary (and artificial) inputs, for a large class of inputs called totally ordered subsets, that have practical significance, the MU-Decoder is vastly superior in area to the LUT-Decoder. In terms …

Design Of A Low Power And Area Efficient Digital Down Converter And Sinc Filter In Cmos 90-Nm Technology, Steven John Billman

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A digital down converter (DDC) typically receives a digital input that has been generated by an analog to digital converter (ADC) operating at intermediate frequency (IF) in an RF receiver chain. The function of the DDC is to down convert the IF signal to baseband in phase (I) and quadrature (Q) signals and is a very important component in wireless receivers. A Digital Down Converter (DDC) is developed based on square wave local oscillators facilitating a multiplier-less implementation with no constraints on the sampling frequency. The DDC includes a pseudo multi-rate SINC low pass filter which exhibits better performance compared …

Self-Calibrating Cricket Motes For Indoor Navigation, Yogendra Jayant Patil

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Global Positioning System (GPS) plays a vital role for providing localization to the autonomous robots. But the quality of the GPS signal degrades in an indoor location and hence GPS cannot be used for indoor localization. Cricket motes are location-aware system that can provide localization service to its users in an indoor location. Cricket motes apply the acoustic ranging technique to find distance between two points. But before a user can use this localization system, assigning coordinate system to the motes requires manual assistance. This project presents a novel algorithm for self-calibration of the cricket motes to a coordinate system …

Structured Silicon Macropore As Anode In Lithium Ion Batteries, Xida Sun

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Porous silicon (PS) membranes for lithium-ion batteries (LIBs) anode applications were developed, demonstrated and characterized systematically in this work. Electrochemical measurements were conducted on both Si-wafer supported and free-standing porous Si membranes. It turned out that the specific capacity of LIBs was enhanced remarkably by PS based anode. PS was fabricated by using electrochemical anodization in a mixed solution of Dimethylformamide (DMF) and Hydrofluoric acid (HF wt.49%). By varying the anodization conditions, including HF concentration, anodization etching time and current density, pores were formed in a p-type (1-20Ω cm) boron-doped silicon substrate. Scanning electron microscopy (SEM) was employed to investigate …

Graphene Based Rf/Microwave Impedance Sensing And Low Loss Conductor For Rf Applications, Iramnaaz Iramnaaz

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Biosensors are becoming more popular recently and expanding due to their broad applications in detecting disease and infectious agents, monitoring of environmental toxins, etc. Recognition and quantification of biochemical molecules and molecular interactions present great challenges in biosensing [38]. Impedance sensing at radio frequency (RF) /microwave frequency becomes very attractive as bio-molecules exhibits large distinct dielectric properties, and also because the ionic conductivity of water in most physiological systems is greatly diminished. For example, it has been reported that tumoral cells exhibits large value of electrical conductivity and permittivity which can result in significant variation of the impedance when compared …

Dynamic Footed With Clock Overlapping And Load Balancing In Multiple Paths For Noise Tolerance In Dynamic Cmos Circuits, Ramadan U. Buzakuk

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Dynamic CMOS circuits are used in microprocessors as well as in circuits that require high speed and small areas. Dynamic CMOS circuits have many advantages but are not robust in noise tolerance in comparison with the legacy static CMOS circuits. In this thesis several noise tolerance techniques that can be implemented with Dynamic CMOS circuits for robust noise tolerance are studied. A dynamic footed with clock overlapping technique integrated with a load balancing multiple-path transistor sizing algorithm for optimizing performance of noise tolerance and speed while in consideration of process variations is presented. Using the 2-bit weighted binary-to-thermometric converter implemented …

Frequency Diverse Array Receiver Architectures, Aaron M. Jones

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Typical radar systems are limited to energy distribution characteristics that are range independent. However, operators are generally interested in obtaining information at particular ranges and discarding elsewhere. It seems appropriate then to attempt to put energy solely at the range(s) of interest, thus minimizing exposure to clutter, jammers and other range-dependent interferences sources. The frequency diverse array (FDA) can provide a mechanism to achieve range-dependent beamforming and the spatial energy distribution properties are investigated on transmit and receive for different architectures herein.

While simplified FDA receive architectures have been explored, they exclude the return signals from transmitters that are not …

Commercial Program Development For A Ground Loop Geothermal System: G-Functions, Commercial Codes And 3d Grid, Boundary And Property Extension, Kyle L. Hughes

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The rise in fossil fuel consumption and green house gas emissions has driven the need for alternative energy and energy efficiency. At the same time, ground loop heat exchangers (GLHE) have proven capable of producing large reductions in energy use while meeting peak demands. However, the initial cost of GLHEs sometimes makes this alternative energy source unattractive to the costumer. GLHE installers use commercial programs to determine the length of pipe needed for the system, which is a large fraction of the initial cost. These commercial programs use approximate methods to determine the length of pipe mainly due to their …

Direct Digital Frequency Synthesizer Architecture For Wireless Communication In 90 Nm Cmos Technology, Tri Trong Nguyen

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Software radio is one promising field that can meet the demands for low cost, low power, and high speed electronic devices for wireless communication. At the heart of software radio is a programmable oscillator called a Direct Digital Synthesizer (DDS). DDS has the capabilities of rapid frequency hopping by digital software control while operating at very high frequencies and having sub-hertz resolution. Nevertheless, the digital-to-analog converter (DAC) and the read-only-memory (ROM) look-up table, building blocks of the DDS, prevent the DDS to be used in wireless communication because they introduce errors and noises to the DDS and their performances deteriorate …

Circuit Techniques On Improving Timing And Noise In Dynamic Cmos, Arvind Vaidyanadeswaran

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Dynamic CMOS are widely employed in high-performance CMOS chips due to high speed and less area in comparison with Static CMOS. However, Dynamic CMOS circuits are inherently less noise tolerant than Static CMOS circuits. This problem becomes more severe with aggressive technology scaling into nanometer process, particularly caused by the charge sharing, the sub-threshold leakage current, the power rail noise and the crosstalk noise. In this thesis, circuit techniques on improving both timing and noise of Dynamic CMOS are presented. A comparison with previous reported work is also presented. Simulations proved that the proposed circuit techniques can achieve a high …

Real-Time Fault Diagnosis Of Automotive Electrical Power Generation And Storage System, Luis Farfan-Ramos

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Automobiles depend more and more on electric power. Analysis of warranty data by automotive OEMs shows that faults in the automotive electrical power generation and storage (EPGS) system are often misdiagnosed. Therefore, monitoring of the state of health (SOH) of the automotive EPGS system is vital for early and correct diagnosis of faults in it, ensuring a reliable supply of electric power to the vehicle and reducing maintenance costs. In this research project, a model-based SOH monitoring method for the EPGS system is developed without the requirement of an alternator current sensor. A model representing the dynamic relationship between the …

Dc-Dc Power Converter Design For A Portable Affordable Welder System (Paws), Curt Stephen Zackiewicz

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Arc welding machines are typically large, heavy devices that transform an alternating current (AC) input into a low-voltage, direct current (DC) output. Traditionally these high power devices have required steel and copper transformers that account for their bulky size and weight. While the cost of raw materials in electromagnetic components has been increasing the cost of high-power silicon devices has been decreasing. This disparity creates an opportunity for a cost-effective DC-DC switching welder in the consumer market. While DC-DC power electronics are not new to the welding industry, this study, under the commission of a welding equipment manufacturer, aims to …

Analysis And Design Of Pulse-Width Modulated Two-Switch Forward Dc-Dc Converter For Universal Laptop Adapter, Venkata Sai Aditya Kumar Choragudi

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The objective of this research is to analyze, design and simulate a two-switch forward pulse-width modulated (PWM) DC-DC converter. The Forward PWM DC-DC converter is originally derived from the buck converter by the addition of a transformer. The transformer is mainly used as a safety feature to electrically isolate input and output stages of the power converter and also to scale the voltage or current. The steady-state analysis is presented for the two-switch PWM DC-DC forward converter in continuous conduction mode (CCM). Based on the analysis, the design equations for two-switch PWM forward DC-DC converter are derived. A design example …

Observer-Based Fault Diagnosis Of Wind Turbines, Songling Zhao

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Because wind is a clean and renewable energy, it is in high demand as an alternative resource of fossil fuels for our daily power supply. Thus, wind turbine technology is wildly applied to convert the wind energy to electrical power. With the size of the wind turbines increased, the maintenance cost of the wind turbines also goes up. Fault diagnosis can significantly help wind turbines to: reduce the maintenance cost, the machinery breakdown, spare parts inventories, total machine downtime, and overtime expenses, and increase machine life, overall productivity, and profit. The technical challenges for fault diagnosis of the wind turbine …

High-Frequency Wide-Range All Digital Phase Locked Loop In 90nm Cmos, Prashanth Muppala

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This thesis presents a high-frequency wide tuning range all digital phase locked loop (ADPLL) in 90 nm CMOS process with 1.2 V power supply. It operates in the frequency range of 2-7.2 GHz with wide linearity and high resolution. The ADPLL uses a wide frequency range digital controlled oscillator (DCO) and averaging technique to obtain fast lock time. The operation of the ADPLL includes both a frequency acquisition state and a phase acquisition state. A novel architecture is implemented in a coarse stage to obtain a monotonically increasing wide frequency range DCO for frequency acquisition and a fine control stage …

Ab Initio Simulations Of Graphene-Based Nanosensor For Detecting No2 And Li, Ahmed Jama Hassan

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Nanosensors, i.e., sensors based on nanomaterials, have the potential of superior performance owing to their size effect, and can have significant effects on detection of pollutants in the environment. Various nanowires have been used in this context. Here we investigate the possibility of NO2 and Li detection using the quantum conductance change in graphene nanoribbon. Quantum conductance modification in graphene nanoribbon upon NO2/Li adsorption was calculated using ab initio methods. The optimized structures of the adsorbed NO2 indicated two different geometries where either nitrogen or oxygen was closer to the graphene lattice. The former resulted in charge transfer from NO2 …

Characterization Of Room Temperature Terahertz Direct Detectors, Carla Renee Boggs

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Room temperature direct detectors operating in the so-called Terahertz (THz) region of the electromagnetic spectrum, and representing the most common detection technologies currently available, were characterized at 104, 280 GHz or 600 GHz within their intended range of operating frequencies. These detectors included commercial Schottky-diode rectifiers (Virginia Diodes and Spacek Labs), commercial pyroelectric detectors (Spectrum Detector), and a commercial Golay cell (QMCI). The characterization included antenna patterns, responsivity, electrical noise, noise equivalent temperature difference (NEΔT ), and noise equivalent power (NEP). Since all the characterization measurements were made the same way, quantitative comparisons can be made between the performances of …

Spatio-Temporal Cardiac Pacing Sites Localization And Time Varying Pericardium Potential Maps Projection Using Ecg Precordial Leads And A Single Moving Dipole Model, Jaime R. De La Cruz

Open Access Theses & Dissertations

A novel non-invasive method for the spatiotemporal localization of the sites of strongest cardiac activity, and for the creation of time varying Pericardium Potential Maps (PPM), with the use of patients' ECG precordial leads, is proposed in this Thesis study. Compared to previous studies, which analyze electrocardiograms in either time domain or spatial domain, the proposed method has the advantage of a simultaneous spatiotemporal electrocardiograph analysis and a 3-D visualization of pericardium potentials maps, as well as, the pericardium surface polarization patterns during the cardiac cycle. The spatial properties added to the electrocardiogram allow for the analysis of specific regions …

Preserving Useful Info While Reducing Noise Of Physiological Signals By Using Wavelet Analysis, Jeffrey Lam

UNF Graduate Theses and Dissertations

Wavelet analysis is a powerful mathematical tool commonly used in signal processing applications, such as image analysis, image compression, image edge detection, and communications systems. Unlike traditional Fourier analysis, wavelet analysis allows for multiple resolutions in the time and frequency domains; it can preserve time information while decomposing a signal spectrum over a range of frequencies. Wavelet analysis is also more suitable for detecting numerous transitory characteristics, such as drift, trends, abrupt changes, and beginnings and ends of events. These characteristics are often the most important and critical part of some non-stationary signals, such as physiological signals. The thesis focuses …

Forward Error Correction In Memoryless Optical Modulation, David Rhys Jones

UNF Graduate Theses and Dissertations

The unprecedented growth in demand for digital media has led to an all-time high in society’s demand for information. This demand will in all likelihood continue to grow as technology such as 3D television service, on-demand video and peer-to-peer networking continue to become more common place. The large amount of information required is currently transmitted optically using a wavelength division multiplexing (WDM) network structure. The need to increase the capacity of the existing WDM network infrastructure efficiently is essential to continue to provide new high bandwidth services to end-users, while at the same time minimizing network providers’ costs. In WDM …

Modeling Impulse Oscillometry Data: Using Augmented-Ric And Extended-Ric Respiratory Impedance Model Paramaters To Track Pulmonary Health And Disease, Carlos Domingo Ramos Rocha

Open Access Theses & Dissertations

Respiratory diseases are a great health concern. Early detection of disease could greatly improve quality of life and yet the most common pulmonary function test can be an unreliable diagnostic method, especially in the case of children. A reliable method of detecting and assessing small airway impairment could greatly help with timely diagnosis. This research approaches this problem by taking Impulse Oscillometry (IOS) data and its model-derived parameters and assessing their utility in tracking respiratory function and more specifically, small airway function.

This research first describes the use of electric circuits as models to describe lung properties at distinct regions …

Mixed-Signal Distributed Feature Extraction For Classification Of Wide-Band Acoustic Signals On Sensor Networks, Humberto Santacruz

Open Access Theses & Dissertations

This thesis proposes a distributed/collaborative scheme for the classification of wide-band acoustic events within the context wireless sensor networks (WSNs). The proposed method is characterized by a mixed-signal processing scheme for the extraction of feature vectors which reduces the processing, memory allocation, and power requirements of the sensor nodes. The mixed-signal scheme assumes that nodes have an analog frontend consisting of a microphone, a bandpass filter, a squaring element and an integrator. This chain of components produces an estimate of the energy over the frequency subband extracted by the filter. The WSN has the ability to form a distributed filter …

Development And Validation Of Biomechanical Models To Quantify Horse Back Forces At The Walk In Three Horse Breeds, Laxmi Raghunandana Kaidapuram

LSU Master's Theses

Therapeutic horseback riding is a common component of physical therapy programs. Quantification of the horse back forces will provide vital information to match therapeutic riders with equine partners. To meet this medical need, a model to quantify the horse back forces from ground reaction forces was developed to test the hypothesis that the forces transferred to a static weight on the horse’s back can be predicted given horse breed and weight. Simultaneous, real time kinetic, kinematic, and back force data on a static weight were collected from 7 adult horses: 3 thoroughbreds, 3 quarter horses, and 1 paso fino. An …

Surface-Enhanced Raman Spectroscopy Substrates Based On Nanoporous Silicon And Pattern Transfer, Pallavi Rao Malempati

LSU Master's Theses

Surface-enhanced Raman scattering enhances the weak Raman scattering by using a roughened metal-coated surface as a catalyst. Roughness in the nanometer range provides the best enhancement. The nanostructures for the surface-enhanced Raman spectroscopy (SERS) substrates, in this work, are generated using an electrochemical etching process on silicon substrates. The patterns of nanoporous silicon thus generated are transferred onto transparent polydimethylsiloxane (PDMS) substrates using the “lift-off” process. An incomplex sputtering technique is employed to coat this substrate with a ~20 nm aluminum layer. Rhodamine 6G (R6G) molecules, when adsorbed to this metal surface, form the final SERS substrate that undergoes Raman …

Parameter Tuning And Experimental Results Of Power System Stabilizer, Bixiang Tang

LSU Master's Theses

Power system stabilizers (PSS) have been studied for many years as a method to increase power system stability. This thesis focuses on the tuning and structure of the power system stabilizer. Different types of power system stabilizers are reviewed. The one studied in this thesis is the integral of accelerated power stabilizer. The generator control system is introduced to illustrate the working environment of the PSS. The mathematic model of the generator, automatic voltage regulator and PSS are analyzed and the system transfer function in presence of the PSS is derived. Base on the transfer function, a new tuning method …