Engineering Commons^™

Prototype Micro Sensors For The Detection Of Pesticide Residues On Blueberries, Guang Chen

Electronic Theses and Dissertations

The widespread use of pesticides on commercial food crops can result in short and long term health problems for both f m workers and consumers as well as serious impacts on the environment. Consequently, there is an increasing need to develop low cost portable detection systems that can be used to screen for pesticide residues on food products. Since phosmet (C1 IH12N04PS2) is one of the most commonly used organophosphorous pesticides within the state of Maine, it is selected as the target pesticide to detect in this thesis. Two sensing techniques were investigated. One is the quartz crystal microbalance (QCM), …

High Frequency Communication System Modeling And Performance Enhancement, Employing Novel Adaptive Dsp Techniques, Murad M. Qahwash

Retrospective Theses and Dissertations

High Frequency (HF) communication has been shown to be a useful communication technique from the very beginning of World War I and it accelerated during World War II. This is attributed to its simplicity, ability to provide near globe connectivity at low power without repeaters, moderate cost, and ease of proliferation [1]. In fact, the HF communication system utilizes the ionosphere [2][3][4] to refract the skywave signals to a distant receiver. This ionospheric channel has some disadvantages. First, it is a non-stationary channel as the HF frequency propagation is a function of the sun spot activities, solar winds, and diurnal …

New Architecture For Heterogeneous Real-Time Simulation, Mandar Anil Mathure

Retrospective Theses and Dissertations

This thesis investigates a new architecture for modeling and simulating complex distributed real-time systems. Modeling adequately a large distributed real time system may involve, due to its complexity, several different theoretical vehicles such as queuing theory, finite state machines, and others. Currently there are no software tools, which would offer combining such heterogeneous features into a single comprehensive simulation environment.

This study involves integrating 3 tools, SES/workbench, an offline simulator using queuing theory as its modeling discipline, ObjecTime as a real-time simulator based on finite state machines as its modeling discipline, and VxWorks real-time kernel used for free modeling in …

Implementation Of An Underwater Digital Acoustic Telemetry Reciever, Raymond A. Mcavoy

Electronic Theses and Dissertations

This thesis presents the design and software implementation of an underwater acoustic modem receiver. Communication links in underwater environments face several undesired effects. These include multipath signal reflections, intersymbol interference, and channel fading. This receiver design uses a combination of time and spatial diversity inputs combined with an adaptive feedback equalizer to counteract those effects. The design is based on three modules. A front-end module demodulates and Doppler-compensates the incoming data. A channel combiner module receives data from one or more front ends for spatial diversity and combines repeated transmissions for time diversity. The data from each input channel is …

Design And Analysis Of Class Ab Rf Power Amplifier For Wireless Communication Applications, Mohamed El-Dakroury

Retrospective Theses and Dissertations

The Power Amplifier is the most power-consulting block among the building blocks of RF transceivers. It is still a difficult problem to design power amplifiers, especially for linear, low voltage operation. Until now power amplifiers for wireless applications is being produced almost in GaAs processes with some exceptions in LDMOS, Si BJT, and SiGe HBT. The submicron CMOS processes for power amplifiers are under research focus since CMOS offers integration for power amplifier with rest of the transceivers blocks due to its high yield. Also CMOS process is cheap.

This thesis report details the design process of a class AB …

Computing Moments Of A Binary Horizontally/Vertically Convex Image Using Run-Time Reconfiguration, Cheowway Neoh

LSU Master's Theses

In this thesis, we present a design for computing moments of a binary horizontally/vertically convex image on an FPGA chip, using run-time reconfiguration. We compute the moments of up to third order for a total of 16 moments. We address how run-time reconfiguration speeds up moment computations without taking up huge hardware resources. Since we are considering a binary horizontally/vertically convex image, we look at an alternative method in moment computations that utilizes constant coefficient multipliers. We divide the image into segments and process one segment at a time. We reconfigure the constant coefficient multipliers before processing the next segment. …

Optimal Channel Equalization For Filterbank Transceivers In Presence Of White Noise, Ehab Farouk Badran

LSU Doctoral Dissertations

Filterbank transceivers are widely employed in data communication networks to cope with inter-symbol-interference (ISI) through the use of redundancies. This dissertation studies the design of the optimal channel equalizer for both time-invariant and time-varying channels, and wide-sense stationary (WSS) and possible non-stationary white noise processes. Channel equalization is investigated via the filterbank transceivers approach. All perfect reconstruction (PR) or zero-forcing (ZF) receiver filterbanks are parameterized in an affine form, which eliminate completely the ISI. The optimal channel equalizer is designed through minimization of the mean-squared-error (MSE) between the detected signals and the transmitted signals. Our main results show that the …

Mobile Home Security With Gprs, Duy Nguyen

Theses : Honours

This thesis presents the results of an honours project on the development of a security system for use on mobile devices. Mobile Home Security (MHS) is a prototype system that aimed to fully investigate a potential use of the wireless high-speed technology General Packet Radio Service (GPRS) in transmitting video from a static location. This thesis Mobile Home Security with GPRS describes in detail the design and developmental stages for the system. The research focused on the sending of video from a security capture device over a high speed radio network. The first stage of the research involved the design …

Modulation Classification Of Digital Communication Signals, Visalakshi S. Ramakonar

Theses: Doctorates and Masters

Modulation classification of digital communications signals plays an important role in both military and civilian sectors. It has the potential of replacing several receivers with one universal receiver. An automatic modulation classifier can be defined as a system that automatically identifies the modulation type of the received signal given that the signal exists and its parameters lie in a known range. This thesis addresses the need for a universal modulation classifier capable of classifying a comprehensive list of digital modulation schemes. Two classification approaches are presented: a decision-theoretic (DT) approach and a neural network (NN) approach. First classifiers are introduced …

Design And Analysis Of Optical Layouts For Free Space Optical Switching, Kung-Meng Lo

Theses: Doctorates and Masters

The Intelligent Reconfigurable Optical Switch (IROS) is an N x N optical switch that uses two reflective Liquid Crystal (LC) Spatial Light Modulators (SLM} in a "Z" configuration to steer the incoming beams from the input ports to the designated output ports. Currently, the maximum steering capacity of practical SLM is limited to few degrees. For a dense optical switch, this makes the optical path between the input and output fiber ports relatively long. When a Gaussian beam is switched from an input fiber port to an output fiber port in a long free space interconnection topology, the beam's illumination …

Improvement Of Resonant Harmonic Filter Effectiveness In The Presence Of Distribution Voltage Distortion, Herbert L. Ginn

LSU Doctoral Dissertations

Resonant harmonic filters (RHFs), are the most common devices installed in distribution systems for reducing distortion caused by harmonic generating loads. When such filters are applied in systems with a distorted distribution voltage their effectiveness may decline drastically. This dissertation explores the causes of degradation of RHFs effectiveness and suggests methods of their improvement both by optimization algorithms and by modification of the filter structure. An optimization based design method is developed for the conventional RHF. It takes into consideration the interaction of the filter with the distribution system and provides a filter which gives the maximum effectiveness with respect …

Three-Dimensional Micromachined On-Chip Inductors For High Frequency Applications, Nimit Chomnawang

LSU Doctoral Dissertations

Demands for wireless communication are ever-escalating for consumer and military communication applications. The requirements of portability, more functionality and lower cost have been driving forces toward smaller, more sophisticated and flexible wireless devices with lower power consumption. To meet these requirements, monolithically integrated passive inductors with high Q-factors and high self-resonant frequencies are desirable. Q-factor and self-resonant frequency of an inductor are significantly degraded at high frequencies due to conductor ohmic loss, magnetically induced eddy current in the conductive substrate, and lower self-resonant frequency from capacitance between conductive substrate and conductors.
In this dissertation, novel three-dimensional arch-like solenoid and dome-shaped …

Wavelength Assignment In All-Optical Networks For Mesh Topologies, Prabhulaiah Bijja

LSU Master's Theses

All-Optical Networks employing Dense Wavelength Division Multiplexing (DWDM) are believed to be the next generation networks that can meet the ever-increasing demand for bandwidth of the end users. This thesis presents some new heuristics for wavelength assignment and converter placement in mesh topologies. Our heuristics try to assign the wavelengths in an efficient manner that results in very low blocking probability. We propose novel static and dynamic assignment schemes that outperform the assignments reported in the literature even when converters are used. The proposed on-line scheme called "Round-Robin" assignment outperforms previously proposed strategies such as first-fit and random assignment schemes. …

A Factorization Approach For Solving The Hamilton-Jacobi Equations In Nonlinear Optimal Control, Mohammad Dikko Aliyu

LSU Doctoral Dissertations

The Hamilton-Jacobi equation (HJE) arose early in the last century in the study of the calculus of variation, classical mechanics and Hamiltonian systems. Recently, there has been a renewed interest in HJEs arising in various analysis and synthesis problems in systems theory. The HJE despite providing a necessary and sufficient condition for an optimal control, is very difficult to solve for general nonlinear systems, and therefore its application remained limited to linear systems. Yet, the HJE has been studied extensively in the literature from diverse areas of science and engineering, varying from mathematical physics, to mechanics, control theory, and to …

Memory Optimization Techniques For Embedded Systems, Jinpyo Hong

LSU Doctoral Dissertations

Embedded systems have become ubiquitous and as a result optimization of the design and performance of programs that run on these systems have continued to remain as significant challenges to the computer systems research community. This dissertation addresses several key problems in the optimization of programs for embedded systems which include digital signal processors as the core processor. Chapter 2 develops an efficient and effective algorithm to construct a worm partition graph by finding a longest worm at the moment and maintaining the legality of scheduling. Proper assignment of offsets to variables in embedded DSPs plays a key role in …

Multiband Analog-To-Digital Conversion, Scott Saucier

Electronic Theses and Dissertations

The current trend in the world of digital communications is the design of versatile devices that may operate using several different communication standards in order to increase the number of locations for which a particular device may be used. The signal is quantized early on in the reciever path by Analog-to-Digital Converters (ADCs), which allows the rest of the signal processing to be done by low complexity, low power digital circuits. For this reason, it is advantageous to create an architecture that can quantize different bandwidths at different frequencies to suit several different communication protocols. This thesis outlines the design …

Video Indexing And Retrieval Techniques Using Novel Approaches To Video Segmentation, Characterization, And Similarity Matching, Waleed Ezzat Farag

Computer Science Theses & Dissertations

Multimedia applications are rapidly spread at an ever-increasing rate introducing a number of challenging problems at the hands of the research community, The most significant and influential problem, among them, is the effective access to stored data. In spite of the popularity of keyword-based search technique in alphanumeric databases, it is inadequate for use with multimedia data due to their unstructured nature. On the other hand, a number of content-based access techniques have been developed in the context of image indexing and retrieval; meanwhile video retrieval systems start to gain wide attention, This work proposes a number of techniques constituting …

Robust Generalised Predictive Control - An Optimal Design For Uncertain Systems, Thomas O'Mahony

Theses

One of the more popular model predictive control approaches, of late, is the generalised predictive controller (GPC). It has received widespread dissemination in academia and numerous successful applications in industry testify to its usefulness. Its popularity partly stems from its superiority over its predecessors, its simplicity and its control acumen. However, since GPC is based on a mathematical model of the process, significant deterioration in performance or even closed-loop instability may arise due to the inevitable discrepancies that arise between the model and the true system. To ensure that the loop stability is not compromised and an adequate level of …

Efficient Convolvers Using The Polynomial Residue Number System Technique, Surendar Paruchuri

LSU Master's Theses

The problem of computing linear convolution is a very important one because with linear convolution we can mechanize digital filtering. The linear convolution of two N-point sequences can be computed by the cyclic convolution of the following 2N-point sequences. The original sequence padded with N zero’s each. The cyclic convolution of two N-point sequences requires multiplications and additions for its computation. A very efficient way of computing cyclic convolution of two sequences is by using the Polynomial Residue Number System (PRNS) technique. Using this technique the cyclic convolution of two N-point sequences can be computed using only N multiplications instead …

Ternary And Quaternary Logic To Binary Bit Conversion Cmos Integrated Circuit Design Using Multiple Input Floating Gate Mosfets, Harish N. Venkata

LSU Master's Theses

Multiple-input floating gate MOSFETs and floating gate potential diagrams have been used for conversion of ternary-valued input and quaternary-valued input into corresponding binary-valued output in CMOS integrated circuit design environment. The method is demonstrated through the design of a circuit for conversion of ternary inputs 00 to -1-1 (decimal 0 to -4) and 00 to 11 (decimal 0 to +4) into the corresponding binary bits and for conversion of quaternary inputs (decimal 0 to 3) into the corresponding binary bits (binary 00 to 11) in a standard 1.5 mm digital CMOS technology. The physical design of the circuits is simulated …

Extensible Data Storage And Presentation Technology For An Ophthalmology Electronic Patient Record, Markus H. Heinrichs

Theses

The Electronic Patient Record (EPR) is a central element of practice systems used in ophthalmology. It acts as a repository for multi-media patient care data as well as billing information, serving healthcare providers and ultimately their patients. The aim of this thesis is to create both a data structure and a flexible on-screen representation of an EPR for an ophthalmology practice, and to provide an XML-based experimental prototype as a “proof of concept” which could ultimately be used as an replacement for an existing DOS- based solution. The medical background and requirements for this system will be described. The state-of-the-art …

Adaptive Radio Resource Management For 2.5g Cellular Networks, Ken Murray

Theses

Recent years have seen a dramatic increase in demand for mobile communication services and with the introduction of 2.5G services such as general packet radio service, this trend is expected to increase further. These new services will introduce highly dynamic tele-traffic variations due to the inherent variability in resource usage of the new data services. The net effect will be considerable increase in load on the available radio resources. The currently employed fixed channel allocation scheme lacks the flexibility to support such traffic variations. A plethora of dynamic channel allocation schemes have been proposed in the past in an effort …

Servo Response And Modelling Issues In Generalised Predictive Control, Ben Griffin

Theses

One of the more popular control strategies, of late, is the Generalised Predictive Controller (GPC). It has received widespread dissemination in academia and numerous successful applications in industry testify to its usefulness. Its popularity partly stems from its superiority to its predecessors, e.g. the generalised minimum variance and pole-placement controllers, but also from the GPC ‘tuning knobs’, which have simple time-domain interpretations and extremely robust default settings. However, despite the widespread interest, there would appear to be some issues relating to the specification of the closed-loop serv^o response that have not been covered in any great detail in the GPC …

Design And Analysis Of Radio Frequency Deployment Algorithms For Gsm, Mónica Pérez-Carbonell

Theses

Due to the growth of the subscriber base and the introduction of new services, mobile communications networks’ demand for wireless resources is increasing. This has resulted in an increasing need to change the frequency allocation of a network in order to adapt the cellular network to new frequency demands.

Currently, a planning tool generates a new frequency plan, which is. then deployed to cell sites. The deployment should ideally be carried out with minimum disruption to network operation, which makes this deployment process a critical undertaking as any errors during or after the deployment can leave the network with poor …

Offline And Online Variants Of The Traveling Salesman Problem, John Ebenezer Augustine

LSU Master's Theses

In this thesis, we study several well-motivated variants of the Traveling Salesman Problem (TSP). First, we consider makespan minimization for vehicle scheduling problems on trees with release and handling times. 2-approximation algorithms were known for several variants of the single vehicle problem on a path. A 3/2-approximation algorithm was known for the single vehicle problem on a path where there is a fixed starting point and the vehicle must return to the starting point upon completion. Karuno, Nagamochi and Ibaraki give a 2-approximation algorithm for the single vehicle problem on trees. We develop a Polynomial Time Approximation Scheme (PTAS) for …