Electrical and Computer Engineering Commons^™

A Variable Step-Size Normalized Sign Algorithm For Acoustic Echo Cancelation, Tiange Shao, Yahong Rosa Zheng, Jacob Benesty

Electrical and Computer Engineering Faculty Research & Creative Works

A variable step size normalized sign algorithm (VSS-NSA) is proposed, for acoustic echo cancelation, which adjusts its step size automatically by matching the L1 norm of the a posteriori error to that of the background noise plus near-end signal. Simulation results show that the new algorithm combined with double-talk detection outperforms the dual sign algorithm (DSA) and the normalized triple-state sign algorithm (NTSSA) in terms of convergence rate and stability. ©2010 IEEE.

Modeling And Analysis Of Radial Flux Toroidally Wound Twin Rotor Permanent Magnet Motor, Ravi Kishore Pratapa

LSU Master's Theses

The main objective of current thesis is the study of Radial Flux Twin Rotor Permanent Magnet (RFTWTRPM) motor. The tasks were to review the literature about RFTWTPM motors and model the motor using Finite Element Method Magnetics (FEMM 4.0). Later the performance of RFTWTRPM motor as a brushless dc motor was analyzed by using MATLAB/SIMULINK package. To find the electrical and mechanical parameters of the RFTWTRPM motor, the rotor and stator dimensions of the motor were firstly optimized using linear FEMM model of the motor. The optimized dimensions were used to construct the cylindrical FEMM model. This model was later …

Optimization Of New Chinese Remainder Theorems Using Special Moduli Sets, Narendran Narayanaswamy

LSU Master's Theses

The residue number system (RNS) is an integer number representation system, which is capable of supporting parallel, high-speed arithmetic. This system also offers some useful properties for error detection, error correction and fault tolerance. It has numerous applications in computation-intensive digital signal processing (DSP) operations, like digital filtering, convolution, correlation, Discrete Fourier Transform, Fast Fourier Transform, direct digital frequency synthesis, etc. The residue to binary conversion is based on Chinese Remainder Theorem (CRT) and Mixed Radix Conversion (MRC). However, the CRT requires a slow large modulo operation while the MRC requires finding the mixed radix digits which is a slow …

Integrating Lattice Space-Time Codes Of Highest Rank And Multiplexing Over Rayleigh Fading Channels, Vamshi Krishna Samudrala

LSU Master's Theses

In this thesis, we consider the problem of finding an optimal combination of multiplexing and space-time coding over a MIMO array when a transmitter has a prior knowledge about correlation. Some existing work in this area used multiplexing and space-time coding methods as a technique to achieve capacity over a MIMO wireless channel. In this work, we consider a 2x2 lattice space-time code of highest rank and multiplex it over a MIMO system to improve the bit error rate performance. The main focus of this thesis is to address the problem of switching between spatial multiplexing and space-time coding to …

Development Of A Compact Optical System For A Forward-Looking Endoscope, Anandi Kalyan Dutta

LSU Master's Theses

ABSTRACT Optical Coherence Tomography has been effectively used for endoscopy in many previous studies. In this work, a 2 mm diameter forward-looking endoscope is developed with the help of MEMS technology and Optical Coherence Technology (OCT) to obtain in-vivo cross-sectional images of tissues or body cavities. The design consists of a GRIN lens, optical fiber and MEMS chip that are placed in line to fulfill the aim of achieving a 2 mm diameter probe. A standard assembly process has been established for the probe. An anisotropic etching was performed on the sample chip to create the V-groove for carrying the …

Modeling Pm Rotary-Linear Motors With Twin-Stator Using 3d Femm, Oleksandr Dobzhanskyi

LSU Master's Theses

A rapid growth of automatization nowadays requires electric machines to be adjusted to any technological process. Therefore, a need in machines with two degrees of mechanical freedom (TDMF), which can operate rotationally and linearly, is relatively large. This thesis is directed on the design and study of performance of PM (permanent magnet) rotary-linear synchronous motors with twin-armature as a new type of electric machines which can perform linear, rotational and helical movements. Three stator versions are considered, namely: stator with rotary and linear armatures, two rotary armatures, and two linear armatures. The rotors have PMs skewed with respect to the …

Adaptive Quantization In Wireless Sensor Networks With Encryption, Niharika Konakalla

LSU Master's Theses

We consider the estimation of a deterministic unknown parameter in an encrypted wireless sensor networks. Adaptive quantization is used on the sensor's observation and the outputs of the sensors are then encrypted using a probabilistic cipher. In a conventional fixed quantization scheme, estimation error grows exponentially with the difference between the threshold and the unknown parameter to be estimated. Hence, to avoid this, we used and adaptive quantization scheme where each sensor adaptively adjusts its quantization threshold. We find the Cramer-Rao Lower Bound for the Ally Fusion Center (AFC) and then find the optimal estimate of the unknown parameter for …

Audio Watermarking Using Transformation Techniques, Rajkiran Ravula

LSU Master's Theses

Watermarking is a technique, which is used in protecting digital information like images, videos and audio as it provides copyrights and ownership. Audio watermarking is more challenging than image watermarking due to the dynamic supremacy of hearing capacity over the visual field. This thesis attempts to solve the quantization based audio watermarking technique based on both the Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT). The underlying system involves the statistical characteristics of the signal. This study considers different wavelet filters and quantization techniques. A comparison is performed on diverge algorithms and audio signals to help examine the performance …

Quantification Of Energy Intake Using Food Image Analysis, Sertan Kaya

LSU Master's Theses

Obtaining real-time and accurate estimates of energy intake while people reside in their natural environment is technically and methodologically challenging. The goal of this project is to estimate energy intake accurately in real-time and free-living conditions. In this study, we propose a computer vision based system to estimate energy intake based on food pictures taken and emailed by subjects participating in the experiment. The system introduces a reference card inclusion procedure, which is used for geometric and photometric corrections. Image classification and segmentation methods are also incorporated into the system to have fully-automated decision making.

A Higher-Order Spectro-Temporal Integration Model For Predicting Signal Audibility, Qing Yang, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

A higher-order model to determine audibility of audio signals is presented. Previous models have been energy based (second order) and adequate only for stationary, narrow-band signals. Music, speech and other audio signals are nonstationary and wideband so traditional energy models poorly predict the audibility of these sounds. The predictions from the higher-order model are compared to actual subjective listening tests to show that the higher order, wide-band technique outperforms previous models. ©2010 IEEE.

Design And Characterization Of An Integrate-And-Fire Neural Recording System, Sheng Feng Yen, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

A neuronal recording system for brain-machine interfaces (BMI) based on asynchronous biphasic pulse coding is described. A recording experiment comparing, in parallel, a commercial recording system (Tucker-Davis Technology) and the UF's custom solution (FWIRE) is set up to compare performance. The novel aspect of the UF system is that the analog signal is represented by an asynchronous pulse train, which provides a low-power, low-bandwidth, noise-resistant means for coding and transmission. Based on different front-end hardware settings, recording bandwidth and corresponding reconstruction accuracy can be varied. Taking advantage of neural firing features, the pulse-based approach requires less than 3K pulses/second to …

A Unified Method For Detecting And Isolating Process Faults And Sensor Faults In Nonlinear Systems, Niharika Sonti

Browse all Theses and Dissertations

With the increase in the complexity of control systems design and the demand for more productivity, the possibility of the occurrence of faults in control systems has also significantly increased. In this thesis, a unified method for the fault diagnosis of sensor faults and process faults is developed for a class of Lipschitz nonlinear uncertain systems. The fault detection and isolation (FDI) architecture is comprised of a fault detection estimator and a bank of fault isolation estimators (FIEs), where each FIE is designed, based on the functional structure of a particular fault, in the fault class under consideration. The output …

Fabrication Of Zinc Oxide Thin Films For Renewable Energy And Sensor Applications, Theresa Y. Hill

Browse all Theses and Dissertations

Progress in commercializing renewable energy technologies is being advanced by developments in Zinc Oxide material science. The photovoltaic cell, for example, generates electricity by receiving solar energy into the cell, generating electrons, and simultaneously transporting electrical charge out of the cell. Metals are capable of removing electrical charge but block transmission of sunshine. Glass and plastics are capable of transmitting sunshine but block the removal of electrical charge. Therefore an exterior layer that is both optically transparent and electrically conductive is desirable. Transparent conductive oxides (TCOs) are the ideal material for such applications since they are capable of both functions. …

Theory Of ‘Selectivity’ Of Label-Free Nanobiosensors – A Geometro-Physical Perspective, Pradeep R. Nair, Muhammad A. Alam

Birck and NCN Publications

Modern label-free biosensors are generally far more sensitive and require orders of magnitude less incubation time compared to their classical counterparts. However, a more important characteristic regarding the viability of this technology for applications in Genomics/Proteomics is defined by the ‘Selectivity’, i.e., the ability to concurrently and uniquely detect multiple target biomolecules in the presence of interfering species. Currently, there is no theory of Selectivity that allows optimization of competing factors and there are few experiments to probe this problem systematically. In this article, we use the elementary considerations of surface exclusion, diffusion limited transport, and void distribution function to …

On Momentum Conservation And Thermionic Emission Cooling, Raseong Kim, Changwook Jeong, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

The possibility of increasing the performance of thermionic cooling devices by relaxing lateral momentum conservation is examined. Upper limits for the ballistic emission current are established. It is then shown that for most cases, nonconserved lateral momentum model produces a current that exceeds this upper limit. For the case of heterojunctions with a much heavier effective mass in the barrier and with a low barrier height, however, relaxing lateral momentum may increase the current. These results can be simply understood from the general principle that the current is limited by the location, well or barrier, with the smallest number of …

On Landauer Versus Boltzmann And Full Band Versus Effective Mass Evaluation Of Thermoelectric Transport Coefficients, Changwook Jeong, Raseong Kim, Mathieu Luisier, Supriyo Datta

Department of Electrical and Computer Engineering Faculty Publications

Using a full band description of electronic bandstructure, the Landauer approach to diffusive transport is mathematically related to the solution of the Boltzmann transport equation, and expressions for the thermoelectric parameters in both formalisms are presented. Quantum mechanical and semiclassical techniques to obtain from a full description of the bandstructure, E(k)E(k), the density of modes in the Landauer approach or the transport distribution in the Boltzmann solution are compared and thermoelectric transport coefficients are evaluated. Several example calculations for representative bulk materials are presented and the full band results are related to the more common effective mass formalism. Finally, given …

Simulation Of Spin Field Effect Transistors: Effects Of Tunneling And Spin Relaxation On Performance, Yunfei Gao, Tony Low, Mark S. Lundstrom, Dmitri E. Nikonov

Department of Electrical and Computer Engineering Faculty Publications

numerical simulation of spin-dependent quantum transport for a spin field effect transistor is implemented in a widely used simulator, nanoMOS. This method includes the effect of both spin scattering in the channel and the tunneling barrier between the source/drain and the channel. Accounting for these factors permits setting more realistic performance limits for the transistor, especially the magnetoresistance, which is found to be lower compared to earlier predictions. The interplay between tunneling and spin scattering is elucidated by numerical simulation. Insertion of the tunneling barrier leads to an increased magnetoresistance. Simulations are used to explore the tunneling barrier design issues.

Universality Of Non Ohmic Shunt Leakage In Thin Film Solar Cells, Sourabh Dongaonkar, J. D. Sevaites, G. M. Ford, S. Loser, J. Moore, R. M. Gelfand, H. Mohseni, H. W. Hillhouse, R. Agrawal, M. A. Ratner, T. J. Marks, Mark S. Lundstrom, Muhammad A. Alam

Department of Electrical and Computer Engineering Faculty Publications

http://dx.doi.org/10.1063/1.3518509

Abstract can be found at the above link

Detection Statistics Of Multiple-Pulse Optical Signals Through Atmospheric Turbulence, Jacob C. Brandenburg

Wayne State University Dissertations

Statistics are studied for signal detection in optical communication systems operating through the atmosphere. Optical communication systems with which this study is concerned are those that employ intensity modulation and direct detection. Atmospheric turbulence, which is fluctuations in the atmosphere's optical index of refraction, is a hindrance to optical wireless communications because of the signal fades, called scintillation, it causes at the optical receiver. In order to mitigate the deteriorative effect of turbulence on the communications system, the signal length and detection threshold for the signal detector must be properly chosen.

In this study, mathematical models for photoelectron generation in …

Using Bayesian Inference In Design Applications, Chung Yong Chan

Electronic Theses and Dissertations

This dissertation presents a new approach for solving engineering design problems such as the design of antenna arrays and finite impulse response (FIR) filters. In this approach, a design problem is cast as an inverse problem. The tools and methods previously developed for Bayesian inference are adapted and utilized to solve design problems. Given a desired design output, Bayesian parameter estimation and model comparison are employed to produce designs that meet the prescribed design specifications and requirements. In the Bayesian inference framework, the solution to a design problem is the posterior distribution, which is proportional to the product of the …