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Theses and Dissertations

2008

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Articles 1 - 30 of 187

Full-Text Articles in Physical Sciences and Mathematics

Quad General Tree Drawing Algorithm And General Trees Characterization: Towards An Environment For The Experimental Study On General Tree Drawing Algorithms, Chu Yao Dec 2008

Quad General Tree Drawing Algorithm And General Trees Characterization: Towards An Environment For The Experimental Study On General Tree Drawing Algorithms, Chu Yao

Theses and Dissertations

Information visualization produces (interactive) visual representations of abstract data to reinforce human cognition and perception; thus enabling the viewer to gain knowledge about the internal structure of the data and causal relationships in it. The visualization of information hierarchies is concerned with the presentation of abstract hierarchical information about relationships between various entities. It has many applications in diverse domains such as software engineering, information systems, biology, and chemistry. Information hierarchies are typically modeled by an abstract tree, where vertices are entities and edges represent relationships between entities. The aim of visualizing tree drawings is to automatically produce drawings of …

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Towards The Total Synthesis Of Thioviridamide: Thiyl Radical Approach To The Beta-Thioenamide Linkage Formation, Jung-Hoon Kang Dec 2008

Towards The Total Synthesis Of Thioviridamide: Thiyl Radical Approach To The Beta-Thioenamide Linkage Formation, Jung-Hoon Kang

Theses and Dissertations

We developed an approach to the β-thioenamide linkage contained in the S-(2-aminovinyl)cysteine (avCys) residue of thioviridamide.1,2 Kinetic and thermodynamic control of radical additions of thiols to ynamides were studied for the formation of β-thioenamide linkage. Thiyl radicals are electrophilic and ynamides are electron-rich alkynes. This complementary polarity of the radical and acceptor increases the likelihood of a successful radical addition reaction. Because little is known about these types of compounds (β-thioenamides), we were unsure what kinds of yields and stereoselectivities (cis vs. trans) to expect. The adduct stability is another issue to consider. Fortunately, under typical radical addition conditions, the …

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Cyber Power In The 21st Century, Joseph M. Elbaum Dec 2008

Cyber Power In The 21st Century, Joseph M. Elbaum

Theses and Dissertations

Historically, the United States Congress has acknowledged that a separate branch of military service is required to exert supremacy over each of the recognized Domains of Operation. Throughout the evolution of modern warfare, leading minds in military theory have come to the conclusion that due to fundamental differences inherent in the theory and tactics that must be employed in order to successfully wage war within a domain’s associated environment, a specialized force was needed - until now. With the recent inclusion of Cyberspace as an operational domain by the Department of Defense, the case should be made that it, too, …

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Improving Library Searches Using Word-Correlation Factors And Folksonomies, Maria Soledad Pera Dec 2008

Improving Library Searches Using Word-Correlation Factors And Folksonomies, Maria Soledad Pera

Theses and Dissertations

Libraries, private and public, offer valuable resources to library patrons; however, formulating library queries to retrieve relevant results can be difficult. This occurs because when using a library catalog for library searches, patrons often do not know the exact keywords to be included in a query that match the rigid subject terms (chosen by the Library of Congress) or terms in other fields of a desired library catalog record. These improperly formulated queries often translate into a high percentage of failed searches that retrieve irrelevant results or no results at all. This explains why frustrated library patrons nowadays rely on …

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Ontology Generation, Information Harvesting And Semantic Annotation For Machine-Generated Web Pages, Cui Tao Dec 2008

Ontology Generation, Information Harvesting And Semantic Annotation For Machine-Generated Web Pages, Cui Tao

Theses and Dissertations

The current World Wide Web is a web of pages. Users have to guess possible keywords that might lead through search engines to the pages that contain information of interest and browse hundreds or even thousands of the returned pages in order to obtain what they want. This frustrating problem motivates an approach to turn the web of pages into a web of knowledge, so that web users can query the information of interest directly. This dissertation provides a step in this direction and a way to partially overcome the challenges. Specifically, this dissertation shows how to turn machine-generated web …

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Sub-Circuit Selection And Replacement Algorithms Modeled As Term Rewriting Systems, Eric D. Simonaire Dec 2008

Sub-Circuit Selection And Replacement Algorithms Modeled As Term Rewriting Systems, Eric D. Simonaire

Theses and Dissertations

Intent protection is a model of software obfuscation which, among other criteria, prevents an adversary from understanding the program’s function for use with contextual information. Relating this framework for obfuscation to malware detection, if a malware detector can perfectly normalize a program P and any obfuscation (variant) of the program O(P), the program is not intent protected. The problem of intent protection on programs can also be modeled as intent protection on combinational logic circuits. If a malware detector can perfectly normalize a circuit C and any obfuscation (variant) O(C) of the circuit, the circuit is not intent protected. In …

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Applications Of Operations Research In Domestic Electric Utilities, Jametta Myers Dec 2008

Applications Of Operations Research In Domestic Electric Utilities, Jametta Myers

Theses and Dissertations

Since its inception in the 1950s, operations research has been used in a number of industries, including the energy industry. Documentation of its use in exploration, production, gasoline blending, oil spill management, coal mining, coal handling, and coal mixing is extensive. However, considerably less documented research exists for one significant customer of many of these products: the electric utility. This work reviews refereed literature from United States operations research journals that document the use of operations research in United States electric utility operations. Applications that centered specifically on the areas of thermal energy generation, transmission, distribution, capacity planning, electric power …

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Secureqemu: Emulation-Based Software Protection Providing Encrypted Code Execution And Page Granularity Code Signing, William B. Kimball Dec 2008

Secureqemu: Emulation-Based Software Protection Providing Encrypted Code Execution And Page Granularity Code Signing, William B. Kimball

Theses and Dissertations

This research presents an original emulation-based software protection scheme providing protection from reverse code engineering (RCE) and software exploitation using encrypted code execution and page-granularity code signing, respectively. Protection mechanisms execute in trusted emulators while remaining out-of-band of untrusted systems being emulated. This protection scheme is called SecureQEMU and is based on a modified version of Quick Emulator (QEMU) [5]. RCE is a process that uncovers the internal workings of a program. It is used during vulnerability and intellectual property (IP) discovery. To protect from RCE program code may have anti-disassembly, anti-debugging, and obfuscation techniques incorporated. These techniques slow the …

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Dynamic Load Balancing Of Virtual Machines Hosted On Xen, Terry Clyde Wilcox Dec 2008

Dynamic Load Balancing Of Virtual Machines Hosted On Xen, Terry Clyde Wilcox

Theses and Dissertations

Currently systems of virtual machines are load balanced statically which can create load imbalances for systems where the load changes dynamically over time. For throughput and response time of a system to be maximized it is necessary for load to be evenly distributed among each part of the system. We implement a prototype policy engine for the Xen virtual machine monitor which can dynamically load balance virtual machines. We compare the throughput and response time of our system using the cpu2000 and the WEB2005 benchmarks from SPEC. Under the loads we tested, dynamic load balancing had 5%-8% higher throughput than …

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Nondestructive Evaluation Of Aircraft Composites Using Terahertz Time Domain Spectroscopy, Christopher D. Stoik Dec 2008

Nondestructive Evaluation Of Aircraft Composites Using Terahertz Time Domain Spectroscopy, Christopher D. Stoik

Theses and Dissertations

Terahertz (THz) time domain spectroscopy (TDS) was assessed as a nondestructive evaluation technique for aircraft composites. Material properties of glass fiber composite were measured using both transmission and reflection configuration. The interaction of THz with a glass fiber composite was then analyzed, including the effects of scattering, absorption, and the index of refraction, as well as effective medium approximations. THz TDS, in both transmission and reflection configuration, was used to study composite damage, including voids, delaminations, mechanical damage, and heat damage. Measurement of the material properties on samples with localized heat damage showed that burning did not change the refractive …

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Performance Analysis Of A Light Weight Packet Scanner, Paras Gandhi Dec 2008

Performance Analysis Of A Light Weight Packet Scanner, Paras Gandhi

Theses and Dissertations

The growth of networks around the world has also given rise to threats like viruses and Trojans. This rise in threats has resulted in counter measures for these threats. These counter measures are in the form of applications called firewalls or IDS. The incorporation of these applications in the network results in some delay in communications. The aim of the experiment in this thesis is to measure the delay introduced by such a firewall in the best case and compare it with the communication done on a network without such an application. These experiments are done using a special miniature …

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Energy Efficient Embedded System Design For Medical Care System Using Wireless Sensor Network, Qi Li Dec 2008

Energy Efficient Embedded System Design For Medical Care System Using Wireless Sensor Network, Qi Li

Theses and Dissertations

Recent surveys on medical service systems show that the cost of patient monitoring has grown significantly. The widespread use of portable digital medical device makes it possible to provide a more comprehensive tracking of patient conditions. However, the development of a full scale, distributed health monitoring system is much delayed due to the lack of efficient wireless communication in a large distributed network. This becomes a challenging research topic which is to find a way to provide accurate and real time patient information to medical experts in a fast, efficient and cost effective fashion. This paper proposes a novel solution …

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Wireless Intelligent Structural Health Monitoring System, Belle Ashwin Dec 2008

Wireless Intelligent Structural Health Monitoring System, Belle Ashwin

Theses and Dissertations

Metal structures are susceptible to various types of damages, including corrosion, stress damage, pillowing deformation, cracks etc. These kinds of damages in the metal structures occur mainly due to operational conditions and exposure to the environment. Our research involves a portable integrated wireless sensor system with video camera and ultrasound capabilities which is being developed to investigate corrosion damage on real structures in real time. This system uses images of the metal surfaces, which are captured from an integrated wireless sensor and then quantified and analyzed using computational intelligence. The quantification of the obtained images is done with specialized component …

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Using Geoscience Education Graduate Students To Help Faculty Transform Teaching Practice, Teagan L. Tomlin Dec 2008

Using Geoscience Education Graduate Students To Help Faculty Transform Teaching Practice, Teagan L. Tomlin

Theses and Dissertations

Universities make claims about student learning that graduates don't often achieve and are under pressure to show improvement in teaching and learning in their undergraduate programs. This has been the constant focus of university-level professional development programs, but most teachers are still not using the most effective teaching methods. Individual departments need to find ways to help their instructors overcome three main challenges associated with adopting more effective student-centered teaching methods. No matter what strategy is adopted, instructors need considerable support to 1) change their beliefs about what constitutes effective teaching and learning, 2) learn to effectively implement new strategies, …

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Simulation And Analysis Of Cadmium Sulfide Nanoparticles, Chad Everett Junkermeier Dec 2008

Simulation And Analysis Of Cadmium Sulfide Nanoparticles, Chad Everett Junkermeier

Theses and Dissertations

I used ab initio molecular dynamics calculations to model cadmium sulfide nanoparticles. The nanoparticles were originaly spherical, bulk-like zinc-blende structures. Constant temperature molecular dynamics calculations reveals that CdS nanoparticles that are about 2 nm in diameter and have unpassivated surfaces are in an amorphous structure with short range order. The nearest neighbor distance on the surface of the nanoparticles being near the wurtzite nearest neighbor distance. I wrote the program xyzSTATS and used its results in justifying the amorphous nanoparticles claim. I also estimated the band gap of the CdS nanoparticles with unpassivated dangling bonds.

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Tolerance Intervals In Random-Effects Models, Kakotan Sanogo Dec 2008

Tolerance Intervals In Random-Effects Models, Kakotan Sanogo

Theses and Dissertations

In the pharmaceutical setting, it is often necessary to establish the shelf life of a drug product and sometimes suitable to assess the risk of product failure at the desired expiry period. The current statistical methodology use confidence intervals for the predicted mean to establish the expiry period and prediction intervals for a predicted new assay value or a tolerance interval for a proportion of the population for use in a risk assessment. A major concern is that most methodology treat a homogeneous subpopulation, say batch, either as a fixed effect and therefore uses a fixed-effects regression model (Graybill, 1976) …

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Life History Observations And Determination Of Potential Host Fish Species For Chipola Slabshell, Elliptio Chipolaensis, Lisa Preister Dec 2008

Life History Observations And Determination Of Potential Host Fish Species For Chipola Slabshell, Elliptio Chipolaensis, Lisa Preister

Theses and Dissertations

North America is home to nearly 300 species of freshwater mussels with approximately 80% being found in the southeastern United States. The Federally threatened species, Elliptio chipolaensis (Chipola slabshell), is considered an endemic species to the Chipola River Basin in the Florida panhandle. E. chipolaensis glochidia are released from the female in conglutinates The potential fish host species for Elliptio chipolaensis are the bluegill and redbreast sunfish. Sixty percent of the bluegill successfully transformed E. chipolaensis glochidia into juvenile mussels while 80% of the redbreast sunfish were successful.

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Tolerance And Accumulation Of Copper, Lead And Zinc By Ceratopteris Richardii, Dorothy Jelagat Cheruiyot Dec 2008

Tolerance And Accumulation Of Copper, Lead And Zinc By Ceratopteris Richardii, Dorothy Jelagat Cheruiyot

Theses and Dissertations

Environmental contamination has increased rapidly in recent years. There is a need to develop cheap and environmentally friendly remediation methods. Numerous studies have evaluated the ability plants to remove contaminants from the environment. The present study evaluated the ability of Ceratopteris richardii gametophytes and sporophytes to tolerate copper, lead and zinc and for the sporophytes to accumulate the three metals in their shoots. Spores were sown in plant medium treated with varying concentrations of Cu, Pb and Zn. Fifteen-day- old sporophytes were transferred into medium mixed with varying concentrations of the three metals. Ceratopteris richardii tolerated and accumulated each of …

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Real-Time Automatic Price Prediction For Ebay Online Trading, Ilya Igorevitch Raykhel Nov 2008

Real-Time Automatic Price Prediction For Ebay Online Trading, Ilya Igorevitch Raykhel

Theses and Dissertations

While Machine Learning is one of the most popular research areas in Computer Science, there are still only a few deployed applications intended for use by the general public. We have developed an exemplary application that can be directly applied to eBay trading. Our system predicts how much an item would sell for on eBay based on that item's attributes. We ran our experiments on the eBay laptop category, with prior trades used as training data. The system implements a feature-weighted k-Nearest Neighbor algorithm, using genetic algorithms to determine feature weights. Our results demonstrate an average prediction error of 16%; …

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An Analysis Of Document Retrieval And Clustering Using An Effective Semantic Distance Measure, Nathan Scott Davis Nov 2008

An Analysis Of Document Retrieval And Clustering Using An Effective Semantic Distance Measure, Nathan Scott Davis

Theses and Dissertations

As large amounts of digital information become more and more accessible, the ability to effectively find relevant information is increasingly important. Search engines have historically performed well at finding relevant information by relying primarily on lexical and word based measures. Similarly, standard approaches to organizing and categorizing large amounts of textual information have previously relied on lexical and word based measures to perform grouping or classification tasks. Quite often, however, these processes take place without respect to semantics, or word meanings. This is perhaps due to the fact that the idea of meaningful similarity is naturally qualitative, and thus difficult …

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A See-Ability Metric To Improve Mini Unmanned Aerial Vehicle Operator Awareness Using Video Georegistered To Terrain Models, Cameron Howard Engh Nov 2008

A See-Ability Metric To Improve Mini Unmanned Aerial Vehicle Operator Awareness Using Video Georegistered To Terrain Models, Cameron Howard Engh

Theses and Dissertations

Search and rescue operations conducted in wilderness environments can be greatly aided by the use of video filmed from mini-UAVs. While lightweight, inexpensive and easily transportable, these small aircraft suffer from wind buffeting and may produce video that is difficult to search. To aid in the video search process, we have created a system to project video frames into a 3D representation of the search region. This projection allows us to tie each frame of video to a real-world location, enabling a myriad of novel views, mosaics and metrics that can be used to guide the search including a new …

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Parameter Estimation For The Beta Distribution, Claire Elayne Bangerter Owen Nov 2008

Parameter Estimation For The Beta Distribution, Claire Elayne Bangerter Owen

Theses and Dissertations

The beta distribution is useful in modeling continuous random variables that lie between 0 and 1, such as proportions and percentages. The beta distribution takes on many different shapes and may be described by two shape parameters, alpha and beta, that can be difficult to estimate. Maximum likelihood and method of moments estimation are possible, though method of moments is much more straightforward. We examine both of these methods here, and compare them to three more proposed methods of parameter estimation: 1) a method used in the Program Evaluation and Review Technique (PERT), 2) a modification of the two-sided power …

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Computer-Aided Trauma Decision Making Using Machine Learning And Signal Processing, Soo-Yeon Ji Nov 2008

Computer-Aided Trauma Decision Making Using Machine Learning And Signal Processing, Soo-Yeon Ji

Theses and Dissertations

Over the last 20 years, much work has focused on computer-aided clinical decision support systems due to a rapid increase in the need for management and processing of medical knowledge. Among all fields of medicine, trauma care has the highest need for proper information management due to the high prevalence of complex, life-threatening injuries. In particular, hemorrhage, which is encountered in most traumatic injuries, is a dominant factor in determining survival in both civilian and military settings. This complication can be better managed using a more in-depth analysis of patient information. Trauma physicians must make precise and rapid decisions, while …

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The Hybrid Game Architecture: Distributing Bandwidth For Mmogs While Maintaining Central Control, Jared L. Jardine Nov 2008

The Hybrid Game Architecture: Distributing Bandwidth For Mmogs While Maintaining Central Control, Jared L. Jardine

Theses and Dissertations

Current Massively Multi-player Online Games (MMOGs) have enormous server-side bandwidth requirements. The costs of providing this bandwidth is in turn passed on to the consumer in the form of high monthly subscription fees. Prior work has primarily focused on distributing this bandwidth using peer-to-peer architectures, but these architectures have difficulty preventing cheating, overwhelming low resource peers, and maintaining consistent game state. We have developed a hybrid game architecture that combines client-server and peer-to-peer technologies to prevent cheating, maintain centralized and consistent game state, significantly reduce central server bandwidth, and prevent lower capacity players from being overwhelmed. By dramatically reducing the …

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Investigating The Margins Of Pleistocene Lake Deposits With High-Resolution Seismic Reflection In Pilot Valley, Utah, John V. South Nov 2008

Investigating The Margins Of Pleistocene Lake Deposits With High-Resolution Seismic Reflection In Pilot Valley, Utah, John V. South

Theses and Dissertations

A vast area of the northeastern Great Basin of the western USA was inundated by a succession of Plio-Pleistocene lakes, including Lake Bonneville (28 ka to 12 ka). The Pilot Valley playa, located just east of the Utah-Nevada border near Wendover, Utah, within the eastern Basin and Range Province, represents an 8 to 16 km wide and ~50 km long remnant of these lakes. The playa corresponds to the upper surface of a closed basin that is delimited by two mountain ranges, which are mantled by recent alluvial fans over which the playa sediments have prograded. In order to investigate …

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Photocycloaddition Of Allenes, Crystal Ward Nov 2008

Photocycloaddition Of Allenes, Crystal Ward

Theses and Dissertations

For the past ten years the Fleming research group has been involved in the research of allene compounds. We have explored the synthesis of allenes as well as several reactions involving allenes, such as oxidation and nitrene addition. Recently, we have explored the synthesis and photochemistry of allenic alcohols tethered to silicon. There are literature examples using allenes in synthesis, but very few examples exist using allenes in photochemical cycloaddition reactions. We have found that a diisopropylallenyloxy(cinnamyloxy)silane derivative undergoes [2+2] photochemical cycloaddition to produce a cyclobutylsilane product when irradiated for 60-75 minutes.

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Wolfcampian Development Of The Nose Of The Eastern Shelf Of The Midland Basin, Glasscock, Sterling, And Reagan Counties, Texas, Douglas S. Flamm Nov 2008

Wolfcampian Development Of The Nose Of The Eastern Shelf Of The Midland Basin, Glasscock, Sterling, And Reagan Counties, Texas, Douglas S. Flamm

Theses and Dissertations

The nose of the Eastern shelf of the Midland Basin is a prominent structural and depositional feature present in Glasscock, Sterling, and Howard counties, Texas. This feature has been expressed in many regional maps and mentioned in some literature, but has not otherwise been studied significantly. This study looks at the viability of using an acoustic impedance seismic inversion to interpret the 2nd and 3rd order sequence stratigraphy of the southern portion of the nose of the Eastern shelf along with its shelf to basin transition in Glasscock, Sterling, and Reagan counties during the Wolfcampian (Asselian-Sakmarian) time (Early Permian). The …

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Effect Of A Water Treatment Bmp On Nutrient Spiraling And Leaf Litter Breakdown In An Urban Stream, Megan Leclair Wheeler Oct 2008

Effect Of A Water Treatment Bmp On Nutrient Spiraling And Leaf Litter Breakdown In An Urban Stream, Megan Leclair Wheeler

Theses and Dissertations

Alterations to stream conditions caused by urbanization can compromise valuable ecosystem services, such as nutrient attenuation and carbon processing. A best management practice (BMP) water facility was installed to restore an impaired urban stream in Columbus, GA. This study was conducted to determine the effect of this BMP on nutrient spiraling and leaf litter decomposition in a 2 km stretch of Weracoba Creek. I hypothesized the BMP would (1) reduce leaf mass loss over time and (2) interfere with nutrient concentrations and uptake lengths. I characterized leaf litter decomposition using tulip tree leaves {Liriodendron tulipifera) in 1mm mesh bags deployed …

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Applications Of The Bivariate Gamma Distribution In Nutritional Epidemiology And Medical Physics, Jolene Barker Sep 2008

Applications Of The Bivariate Gamma Distribution In Nutritional Epidemiology And Medical Physics, Jolene Barker

Theses and Dissertations

In this thesis the utility of a bivariate gamma distribution is explored. In the field of nutritional epidemiology a nutrition density transformation is used to reduce collinearity. This phenomenon will be shown to result due to the independent variables following a bivariate gamma model. In the field of radiation oncology paired comparison of variances is often performed. The bivariate gamma model is also appropriate for fitting correlated variances. A method for simulating bivariate gamma random variables is presented. This method is used to generate data from several bivariate gamma models and the asymptotic properties of a test statistic, suggested for …

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Application Of Optimization Techniques To Spectrally Modulated, Spectrally Encoded Waveform Design, Todd W. Beard Sep 2008

Application Of Optimization Techniques To Spectrally Modulated, Spectrally Encoded Waveform Design, Todd W. Beard

Theses and Dissertations

A design process is demonstrated for a coexistent scenario containing Spectrally Modulated, Spectrally Encoded (SMSE) and Direct Sequence Spread Spectrum (DSSS) signals. Coexistent SMSE-DSSS designs are addressed under both perfect and imperfect DSSS code tracking conditions using a non-coherent delay-lock loop (DLL). Under both conditions, the number of SMSE subcarriers and subcarrier spacing are the optimization variables of interest. For perfect DLL code tracking conditions, the GA and RSM optimization processes are considered independently with the objective function being end-to-end DSSS bit error rate. A hybrid GA-RSM optimization process is used under more realistic imperfect DLL code tracking conditions. In …

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