Engineering Commons^™

Automatic Active Contour Modelling And Its Potential Application For Non-Destructive Testing, Srinath Vepathur Sitaraman

LSU Master's Theses

Active contouring techniques are very useful in medical imaging, digital mapping, non-destructive ultrasonic evaluation, etc. Therefore, we try to explore and investigate the advanced automatic active contouring methods, which can benefit the aforementioned applications. In this thesis work, we study the automatic active contour models adopted for the object characterization, whose extensions could include the potential defect analysis in the ultrasonic non-destructive testing. The active contouring scheme (also called a snake) or an energy minimizing spline, is an algorithm which is very sensitive to the manually marked initial points, and thereby requires an expertly operation. Therefore, we make new research …

Information Analysis Of Dna Sequences, Riyazuddin Mohammed

LSU Master's Theses

The problem of differentiating the informational content of coding (exons) and non-coding (introns) regions of a DNA sequence is one of the central problems of genomics. The introns are estimated to be nearly 95% of the DNA and since they do not seem to participate in the process of transcription of amino-acids, they have been termed “junk DNA.” Although it is believed that the non-coding regions in genomes have no role in cell growth and evolution, demonstration that these regions carry useful information would tend to falsify this belief. In this thesis, we consider entropy as a measure of information …

A Configurable Decoder For Pin-Limited Applications, Matthew Collin Jordan

LSU Master's Theses

Pin limitation is the restriction imposed on an IC chip by the unavailability of a sufficient number of I/O pins. This impacts the design and performance of the chip, as the amount of information that can be passed through the boundary of the chip becomes limited. One area that would benefit from a reduction of the effect of pin limitation is reconfigurable architectures. In this work, we consider reconfigurable devices called Field Programmable Gate Arrays (FPGAs). Due to pin limitation, current FPGAs use a form of 1-hot decoder to select elements (one frame at a time) during partial reconfiguration. This …

[Delta] Iddq Testing Of A Cmos 12-Bit Charge Scaling Digital-To-Analog Converter, Kalyan Madhav Golla

LSU Master's Theses

This work presents design, implementation and test of a built-in current sensor (BICS) for ∆IDDQ testing of a CMOS 12-bit charge scaling digital-to-analog converter (DAC). The sensor uses power discharge method for the fault detection. The sensor operates in two modes, the test mode and the normal mode. In the test mode, the BICS is connected to the circuit under test (CUT) which is DAC and detects abnormal currents caused by manufacturing defects. In the normal mode, BICS is isolated from the CUT. The BICS is integrated with the DAC and is implemented in a 0.5 μm n-well CMOS technology. …

Performance Of Torus-Type Brushless Dc Motor With Winding Connected In Two And Three-Phase System, Dinakar Choppa

LSU Master's Theses

A torus-type permanent magnet brushless DC motor is the object of this thesis. The motor can operate with the winding connected either in two - phase or three - phase system. A comparative study of performance of the motor operating in these two systems is the objective of the thesis. To analyze the motor performance, the dynamic models of the motors operating with two - phase and three - phase motors have been proposed. The simulation of motor operation was carried out using the MATLAB/SIMULINK software package. A study of motors operation in steady state conditions has been done by …

Communication Blades: Modular Communications For Tangible And Embedded Interfaces, Karun Kumar Kallakuri

LSU Master's Theses

Bladed Tiles is a modular hardware toolkit for building tangible and embedded interface devices. It includes “function blades” and “interaction tiles,” which can provide a flexible, inexpensive, open-ended platform for constructing a wide variety of tangible and embedded interfaces. In this paper, we propose Communication Blades. These are a class of electronic modules with varied computational capabilities for interfacing devices built using bladed tiles toolkit and also for interfacing embedded devices as adapters with external communication networks. These blades provide flexibility by offering the ability to select between different communication technologies and connectivity by providing devices with interoperability over different …

Robust Fault-Tolerant Control For Aircraft Systems, Phalguna Kumar Rachinayani

LSU Master's Theses

The need to design controllers that guarantee both stability and performance upon the occurrence of faults has been an active area of research. To address this problem, in this thesis we present different methodologies to design robust controllers that guarantee both stability and robustness for actuator faults and uncertainties. In the first part of this thesis, we introduce the classical uncertainty formulation using Linear Fractional Transformation (LFT) and describe LFT's special cases-norm bounded and convex polytopic uncertainty descriptions. Practical methods to formulate these uncertainty structures are described. In the same spirit, formulation of faults and their modeling for robust control …

Design Of Cmos Lc Voltage Controlled Oscillators, Chetan Shambhulinga Salimath

LSU Master's Theses

This work presents the design and implementation of CMOS LC voltage controlled oscillators. On-chip planar spiral inductors and PMOS inversion mode varactors were utilized to implement the resonator. Two voltage controlled oscillators (VCOs) were realized as a part of this work, one designed to operate at 1.1 GHz while the second at 1.8 GHz. Both VCOs were implemented in a scalable digital CMOS process, with the former in a 1.5 micron CMOS process and the latter in a 0.5 micron technology. A simulation based methodology was adopted to arrive at a simple pi model used to model the metal and …

Mapping A Weak Hypercube On An Optical Slab Waveguide, Divya Rengan

LSU Master's Theses

The communication fabric of a parallel processing system is represented as a directed graph. In a weak topology a processor uses at most one incoming edge or one outgoing edge for communication at any given point in time. Currently, the data rate that can be supported on electronic interconnects is reaching its limits. Optical interconnects have been identified as one of the most promising approaches to the growing demands for today's systems. The “medium bandwidth” of an optical waveguide is huge (order of petabits per second for a 1mm2 cross-section optical slab). The challenge lies in utilizing as much of …

Instantaneously Trained Neural Networks With Complex And Quaternion Inputs, Adityan V. Rishiyur

LSU Master's Theses

Neural network architectures such as backpropagation networks, perceptrons or generalized Hopfield networks can handle complex inputs but they require a large amount of time and resources for the training process. This thesis investigates instantaneously trained feedforward neural networks that can handle complex and quaternion inputs. The performance of the basic algorithm has been analyzed and shown how it provides a plausible model of human perception and understanding of images. The motivation for studying quaternion inputs is their use in representing spatial rotations that find applications in computer graphics, robotics, global navigation, computer vision and the spatial orientation of instruments. The …

Performance Of A Three-Phase Permanent Magnet Motor Operating As A Synchronous Motor And A Brushless Dc Motor, Sophie Sekalala

LSU Master's Theses

The performance of a three-phase permanent magnet (PM) motor operating as a synchronous motor and brushless DC (BLDC) motor is discussed. The PM motor, when operating as a synchronous machine, is supplied with constant frequency, meaning constant rotor speed operation. When operating as a BLDC motor, the supply frequency changes according to the actual rotor speed. It means the speed signal is fed back to the controller, which generates the appropriate frequency to supply the stator winding. This means the BLDC motor cannot operate without a position sensor. The objective of the project was to analyze and compare the performance …

A Novel Robust Mel-Energy Based Voice Activity Detector For Nonstationary Noise And Its Application For Speech Waveform Compression, Syed, Q. Waheeduddin

LSU Master's Theses

The voice activity detection (VAD) is crucial in all kinds of speech applications. However, almost all existing VAD algorithms suffer from the nonstationarity of both speech and noise. To combat this difficulty, we propose a new voice activity detector, which is based on the Mel-energy features and an adaptive threshold related to the signal-to-noise ratio (SNR) estimates. In this thesis, we first justify the robustness of the Bayes classifier using the Mel-energy features over that using the Fourier spectral features in various noise environments. Then, we design an algorithm using the dynamic Mel-energy estimator and the adaptive threshold which depends …

Designing Switches For Routing In Circuit-Switched Trees, Dinesh Prasad Venkat Rao

LSU Master's Theses

Reconfigurable computing provides a fast and flexible solution for intensive computing processes. Thus, it acts as a bridge between software controlled and hardware based processors. The self–reconfigurable gate array (SRGA) is a reconfigurable architecture that allows fast switching between operations on a reconfigurable device. It consists of a 2-dimensional array of processing elements (PEs) connected using a binary tree structure, called a circuit-switched tree (CST). A CST is a balanced binary tree in which leaves represent processing elements (PE) and internal nodes represent switches. The PEs in the CST communicates with each other by configuring the appropriate switches in the …

Space-Time Block Coding For Multiple Transmit Antennas Over Time-Selective Fading Channels, Ioannis Erotokritou

LSU Master's Theses

The last decade we have witnessed an extraordinary growing interest in the field of wireless communications. Wireless industry has recently turned into a technology known as Multiple-Input Multiple-Output (MIMO) to minimize errors and optimize data speed. This is done by using multiple transmit and receive antennas, as well as appropriate space-time block code techniques. Due the fact that time-selective fading channels exist, the assumption that the channel is being static over the length of the codeword does not apply in this thesis. The channel state varies over the number of signal intervals, and in such case the orthogonality of the …

A Methanol And Hydrogen Peroxide Fuel Cell Using Non-Noble Catalysts In Alkaline Solution, Woosuk Sung

LSU Master's Theses

A primary goal of this work is to develop a novel liquid-based microscale fuel cell using non-noble metal catalysts. The developed fuel cell is based on a membraneless structure. The operational complications of a proton exchange membrane lead the development of a fuel cell with the membraneless structure. Non-noble metals with relatively mild catalytic activity, nickel hydroxide and silver oxide, were employed as anode and cathode catalysts to minimize the effect of cross reactions with the membraneless structure. Along with nickel hydroxide and silver oxide, methanol and hydrogen peroxide were selected as a fuel at the anode and an oxidant …

Comparative Study Of Axial Flux Permanent Magnet Brushless Dc Motor Operating With The Winding Connected In Single-Phase And Two-Phase System, Sunil Kumar Challa

LSU Master's Theses

The object of the study is a double-sided axial flux permanent magnet brushless dc (AFPM BLDC) motor with salient pole stator. Its winding can be connected either in single-phase or in two-phase system, which results in different operation of the motor.

The objective of the thesis is to analyze and compare the performances of the AFPM BLDC motor with single-phase winding and two-phase winding. To study the motor operation, a mathematical dynamic model has been proposed for each of the motor with different winding, which became the basis for simulations that were performed using MATLAB/SIMULINK software package.

The calculations were …

Resilient Optical Multicasting Utilizing Cycles In Wdm Optical Networks, Abhishek Satyedranath

LSU Master's Theses

High capacity telecommunications of today is possible only because of the presence of optical networks. At the heart of an optical network is an optical fiber whose data carrying capabilities are unparalleled. Multicasting is a form of communication in wavelength division multiplexed (WDM) networks that involves one source and multiple destinations. Light trees, which employ light splitting at various nodes, are used to deliver data to multiple destinations. A fiber cut has been estimated to occur, on an average, once every four days by TEN, a pan-European carrier network. This thesis presents algorithms to make multicast sessions survivable against component …

Compiler Assisted Cache Prefetch Using Procedure Call Hierarchy, Sheela A. Doshi

LSU Master's Theses

Microprocessor performance has been increasing at an exponential rate while memory system performance improved at a linear rate. This widening difference in performances is increasingly rendering advances in computer architecture less useful as more instructions spend more time waiting for data to be fetched from the memory after a cache miss. Data prefetching is a technique that avoids some cache misses by bringing data into the cache before it is actually needed. Different approaches to data prefetching have been developed, however existing prefetch schemes do not eliminate all cache misses and even with smaller cache miss ratio, miss latency remains …

Improved Content Based Watermarking For Images, Arvind Kumar Parthasarathy

LSU Master's Theses

Due to improvements in imaging technologies and the ease with which digital content can be created and manipulated, there is need for the copyright protection of digital content. It is also essential to have techniques for authentication of the content as well as the owner. To this end, this thesis proposes a robust and transparent scheme of watermarking that exploits the human visual systems’ sensitivity to frequency, along with local image characteristics obtained from the spatial domain, improving upon the content based image watermarking scheme of Kay and Izquierdo. We implement changes in this algorithm without much distortion to the …

Design Of Linear Boolean Network Codes For Combination Networks, Shoupei Li

LSU Master's Theses

Network coding is a promising technique to improve the throughput of communication networks. In the thesis, we investigate linear Boolean network codes on a special class of multicast networks, called combination networks. Using companion matrices of primitive polynomials over finite fields, we design a class of symmetric linear Boolean network codes from Reed-Solomon codes for single-source combination networks. We also prove that, for some cases, the linear Boolean network codes are optimal in the sense of minimum network uses. In the thesis, we further consider two-source network coding problem for combination networks and other specific networks. We develop a method …

Em Algorithm For Multiple Wideband Source Localization, Kiran Kumar Mada

LSU Master's Theses

A computationally efficient algorithm using the expectation-maximization (EM) algorithm for multiple wideband source localization in the near field of a sensor array/area is addressed in this thesis. Our idea is to decompose the observed sensor data, which is a superimposition of multiple sources, into the individual components in the frequency domain and then estimate the corresponding location parameters associated with each component separately. Instead of the conventional alternating projection (AP) method, we propose to adopt the EM algorithm in this work; our new method involves two steps, namely Expectation (E-step) and Maximization (M-step). In the E-step, the individual incident source …