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Full-Text Articles in Engineering

Development Of A Model And Localization Algorithm For Received Signal Strength-Based Geolocation, Amanda Sue King Jun 2013

Development Of A Model And Localization Algorithm For Received Signal Strength-Based Geolocation, Amanda Sue King

Theses and Dissertations

Location-Based Services (LBS), also called geolocation, have become increasingly popular in the past decades. They have several uses ranging from assisting emergency personnel, military reconnaissance and applications in social media. In geolocation a group of sensors estimate the location of transmitters using position and Radio Frequency (RF) information. A review of the literature revealed that a majority of the Received Signal Strength (RSS) techniques used made erroneous assumptions about the distribution or ignored effects of multiple transmitters, noise and multiple antennas. Further, the corresponding algorithms are often mathematically complex and computationally expensive. To address the issues this dissertation focused on …

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Fluid-Structure Interactions With Flexible And Rigid Bodies, David J. Daily May 2013

Fluid-Structure Interactions With Flexible And Rigid Bodies, David J. Daily

Theses and Dissertations

Fluid structure interactions occur to some extent in nearly every type of fluid flow. Understanding how structures interact with fluids and visa-versa is of vital importance in many engineering applications. The purpose of this research is to explore how fluids interact with flexible and rigid structures. A computational model was used to model the fluid structure interactions of vibrating synthetic vocal folds. The model simulated the coupling of the fluid and solid domains using a fluid-structure interface boundary condition. The fluid domain used a slightly compressible flow solver to allow for the possibility of acoustic coupling with the subglottal geometry …

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A Multiobjective Optimization Method For Collaborative Products With Application To Engineering-Based Poverty Alleviation, Nicholas Scott Wasley May 2013

A Multiobjective Optimization Method For Collaborative Products With Application To Engineering-Based Poverty Alleviation, Nicholas Scott Wasley

Theses and Dissertations

Collaborative products are created by combining components from two or more products to result in a new product that performs previously unattainable tasks. The resulting reduction in cost, weight, and size of a set of products needed to perform a set of functions makes collaborative products useful in the developing world. In this thesis, multiobjective optimization is used to design a set of products for optimal individual and collaborative performance. This is introduced through a nine step method which simultaneously optimizes multiple products both individually and collaboratively. The method searches through multiple complex design spaces while dealing with various trade-offs …

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Evaluating The Safety Effects Of Signal Improvements, Ashley Lynn Dowell May 2013

Evaluating The Safety Effects Of Signal Improvements, Ashley Lynn Dowell

Theses and Dissertations

As a result of high crash frequencies on roadways, transportation safety has become a high priority for the United States Department of Transportation and the Utah Department of Transportation. A large percentage of fatal and injury crashes on roadways occur at intersections and traffic signals have been implemented to reduce these severe crashes. There is a need to evaluate the effectiveness of the traffic signal improvements through the development of Crash Modification Factors (CMFs). Recent research has shown that traditional safety evaluation methods have been inadequate in developing CMFs. In recent years, Bayesian statistical methods have been utilized in traffic …

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Arrow-Based On-Chip Alkali Vapor-Cell Development, John Frederick Hulbert May 2013

Arrow-Based On-Chip Alkali Vapor-Cell Development, John Frederick Hulbert

Theses and Dissertations

The author presents the successful development of an on-chip, monolithic, integrated rubidium vapor-cell. These vapor-cells integrate ridge waveguide techniques with hollow-core waveguiding technology known as Anti-Resonant Reflecting Optical Waveguides (ARROWs). These devices are manufactured on-site in BYU's Integrated Microelectronic Laboratory (IML) using common silicon wafer microfabrication techniques. The ARROW platform fabrication is outlined, but the bulk of the dissertation focuses on novel packaging techniques that allow for the successful introduction and sealing of rubidium vapor into these micro-sized vapor-cells. The unique geometries and materials utilized in the ARROW platform render common vapor-cell sealing techniques unusable. The development of three generations …

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A Mathematical Model For Quantifying System Evolvability Using Excess And Modularity, Morgan Wesley Parry Tackett May 2013

A Mathematical Model For Quantifying System Evolvability Using Excess And Modularity, Morgan Wesley Parry Tackett

Theses and Dissertations

An important factor in system longevity is service-phase evolvability, which is defined as the ability of a system to physically transform from one configuration to a more desirable configuration while in service. These transformations may or may not be known during the design process, and may or may not be reversible. A study of 210 engineered systems was performed and found that system excess and modularity allow a system to evolve while in service. Building on these observations, this thesis introduces mathematical relationships that map a system's excess and modularity to that system's ability to evolve. These relationships are derived …

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Using Topology Optimization To Numerically Improve Barriers To Reverse Engineering, Devin Donald Lebaron May 2013

Using Topology Optimization To Numerically Improve Barriers To Reverse Engineering, Devin Donald Lebaron

Theses and Dissertations

Here explored is a method by which designers can use the tool of topology optimization to numerically improve barriers to reverse engineering. Recently developed metrics, which characterize the time (T) to reverse engineer a product, enable this optimization. A key parameter use din the calculation of T is information content (K). The method presented in this thesis pursues traditional topology optimization objectives while simultaneously maximizing K, and thus T, in the resulting topology. This thesis presents new algorithms to 1) evaluate K for any topology, 2)increase K for a topology by manipulating macro-scale geometry and micro-scale crystallographic information for each …

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Water Soluble Polymer Solar Cells From Electrospray Deposition, Marshall Sweet May 2013

Water Soluble Polymer Solar Cells From Electrospray Deposition, Marshall Sweet

Theses and Dissertations

This dissertation reports the fabrication and characterization of thin films from the water soluble polymer sodium poly[2-(3-thienyl)-ethyloxy-4-butylsulfonate] (PTEBS) by electrospray deposition (ESD). Contiguous thin films were created by adjusting the parameters of the electrospray apparatus and solution properties to maintain a steady Taylor cone for uniform nanoparticle aerosolization and controlling the particle water content to enable coalescence with previously deposited particles. The majority of deposited particles had diameters less than 52 nm. A thin film of 64.7 nm with a root mean square surface roughness of 20.2 nm was achieved after 40 minutes of ESD. Hybrid Solar Cells (HSCs) with …

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Techniques For Li-Bdn Synthesis For Hybrid Microarchitectural Simulation, Tyler S. Harris May 2013

Techniques For Li-Bdn Synthesis For Hybrid Microarchitectural Simulation, Tyler S. Harris

Theses and Dissertations

Computer designers rely upon near-cycle-accurate microarchitectural simulation to explore the design space of new systems. Unfortunately, such simulators are becoming increasingly slow as systems become more complex. Hybrid simulators which offload some of the simulation work onto FPGAs can increase the speed; however, such simulators must be automatically synthesized or the time to design them becomes prohibitive. Furthermore, FPGA implementations of simulators may require multiple FPGA clock cycles to implement behavior that takes place within one simulated clock cycle, making correct arbitrary composition of simulator components impossible and limiting the amount of hardware concurrency which can be achieved. Latency-Insensitive Bounded …

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An Exploration Of Carbon-Filled Carbon Nanotubes As A Potential Material In Coronary Stents, Kristopher Neil Jones May 2013

An Exploration Of Carbon-Filled Carbon Nanotubes As A Potential Material In Coronary Stents, Kristopher Neil Jones

Theses and Dissertations

The purpose of this research is to explore the potential of using carbon-infiltrated carbon nanotubes (CI-CNT) as a material for coronary artery stents. Stents are commonly fabricated from metal, which may not perform as well as many polymers and ceramics in biomedical applications. Pyrolytic carbon, a ceramic, is currently used in medical implant devices due to its preferrable biocompatibility properties. Micro-patterned pyrolytic carbon devices can be created by growing carbon nanotubes, and then filling the space between with amorphous carbon via chemical vapor deposition. We prepared multiple samples of two different planar stent-like flexible geometries and smaller cubic structures out …

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Comfort And Compatibility Of Silicone Hydrogel Contact Lenses, Ngai Keung Tam May 2013

Comfort And Compatibility Of Silicone Hydrogel Contact Lenses, Ngai Keung Tam

Theses and Dissertations

Silicone Hydrogel (SiHy) contact lenses are highly successful compared to previous soft lenses; they were developed to provide superior oxygen permeability. However, the hydrophobic natures of the silicone segments enhance lipid sorption which may diminish the lens surface wettability, clarity and comfort. While lens and lens care product are designed to remove lipid deposition, there is lack of experimental evidence to evaluate the actual performances with respect to lipid removal. An in vitro model using an artificial tear fluid containing radiolabeled lipids was employed in this thesis research to evaluate the efficacy of different multi-purpose lens care solutions in removing …

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Studies Of Performance And Predictability Of Cache-Locking, Matt Loach May 2013

Studies Of Performance And Predictability Of Cache-Locking, Matt Loach

Theses and Dissertations

Today’s real-time systems need to be faster and more powerful than ever before. Caches are an architectural feature that helps solve this problem. Caches however are unpredictable and do not improve the worst case execution time. This work studies the effects of cache-locking on performance and time predictability. Two locking methods were evaluated: a dynamic locking method and a static locking method. The performance of single and multi-core processors and multiple levels of caches were studied. The time predictability of the single core system was studied and the cost of the time predictability was determined for each locking method. Cache-locking …

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Automatic Segmentation Of Pressure Images Acquired In A Clinical Setting, Anathea Pepperl May 2013

Automatic Segmentation Of Pressure Images Acquired In A Clinical Setting, Anathea Pepperl

Theses and Dissertations

One of the major obstacles to pressure ulcer research is the difficulty in accurately measuring mechanical loading of specific anatomical sites. A human motion analysis system capable of automatically segmenting a patient's body into high-risk areas can greatly improve the ability of researchers and clinicians to understand how pressure ulcers develop in a hospital environment. This project has developed automated computational methods and algorithms to analyze pressure images acquired in a hospital setting. The algorithm achieved 99% overall accuracy for the classification of pressure images into three pose classes (left lateral, supine, and right lateral). An applied kinematic model estimated …

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Modernization Of The Mock Circulatory Loop: Advanced Physical Modeling, High Performance Hardware, And Incorporation Of Anatomical Models, Charles Taylor May 2013

Modernization Of The Mock Circulatory Loop: Advanced Physical Modeling, High Performance Hardware, And Incorporation Of Anatomical Models, Charles Taylor

Theses and Dissertations

A systemic mock circulatory loop plays a pivotal role as the in vitro assessment tool for left heart medical devices. The standard design employed by many research groups dates to the early 1970's, and lacks the acuity needed for the advanced device designs currently being explored. The necessity to update the architecture of this in vitro tool has become apparent as the historical design fails to deliver the performance needed to simulate conditions and events that have been clinically identified as challenges for future device designs. In order to appropriately deliver the testing solution needed, a comprehensive evaluation of the …

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The Design And Validation Of A Computational Model Of The Human Wrist Joint, Afsarul Mir May 2013

The Design And Validation Of A Computational Model Of The Human Wrist Joint, Afsarul Mir

Theses and Dissertations

Advancements in computational capabilities have allowed researchers to turn towards modeling as an efficient tool to replicate and predict outcomes of complex systems. Computational models of the musculoskeletal system have gone through various iterations with early versions employing dramatic simplifications. In this work, a three-dimensional computational model of the wrist joint was developed. It accurately recreated the skeletal structures of the hand and wrist and represented the constraints imposed by soft tissue structures like ligaments, tendons, and other surrounding tissues. It was developed to function as a tool to investigate the biomechanical contributions of structures and the kinematic response of …

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Tissue Engineering Composite Biomimetic Gelatin Sponges For Bone Regeneration, Isaac Rodriguez May 2013

Tissue Engineering Composite Biomimetic Gelatin Sponges For Bone Regeneration, Isaac Rodriguez

Theses and Dissertations

The field of tissue engineering aims to develop viable substitutes with the ability to repair and regenerate the functions of damaged tissue. Common practices to supplement bone regeneration in larger defects include bone graft biomaterials such as autografts, allografts, xenografts, and synthetic biomaterials. Autologous bone grafting is the current gold-standard procedure used to replace missing or damaged bone. However, these grafts have disadvantages such as donor site morbidity, limited availability, and the need for a secondary surgery. The focus of this study is to tissue engineer a lyophilized gelatin composite sponge composed of hydroxyapatite (HA), chitin whiskers (CW), and preparations …

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Image-Based Respiratory Motion Extraction And Respiration-Correlated Cone Beam Ct (4d-Cbct) Reconstruction, Salam Dhou May 2013

Image-Based Respiratory Motion Extraction And Respiration-Correlated Cone Beam Ct (4d-Cbct) Reconstruction, Salam Dhou

Theses and Dissertations

Accounting for respiration motion during imaging helps improve targeting precision in radiation therapy. Respiratory motion can be a major source of error in determining the position of thoracic and upper abdominal tumor targets during radiotherapy. Thus, extracting respiratory motion is a key task in radiation therapy planning. Respiration-correlated or four-dimensional CT (4DCT) imaging techniques have been recently integrated into imaging systems for verifying tumor position during treatment and managing respiration-induced tissue motion. The quality of the 4D reconstructed volumes is highly affected by the respiratory signal extracted and the phase sorting method used. This thesis is divided into two parts. …

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Transient Liquid Phase Bonding Of Titanium-, Iron- And Nickel- Based Alloys, A. H. M. Esfakur Rahman May 2013

Transient Liquid Phase Bonding Of Titanium-, Iron- And Nickel- Based Alloys, A. H. M. Esfakur Rahman

Theses and Dissertations

The operating temperature of land-based gas turbines and jet engines are ever-increasing to increase the efficiency, decrease the emissions and minimize the cost. Within the engines, complex-shaped parts experience extreme temperature, fatigue and corrosion conditions. Ti-based, Ni-based and Fe-based alloys are commonly used in gas turbines and jet engines depending on the temperatures of different sections. Although those alloys have superior mechanical, high temperature and corrosion properties, severe operating conditions cause fast degradation and failure of the components. Repair of these components could reduce lifecycle costs. Unfortunately, conventional fusion welding is not very attractive, because Ti reacts very easily with …

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Modeling, Parameter Estimation, And Navigation Of Indoor Quadrotor Robots, Stephen C. Quebe Apr 2013

Modeling, Parameter Estimation, And Navigation Of Indoor Quadrotor Robots, Stephen C. Quebe

Theses and Dissertations

This thesis discusses topics relevant to indoor unmanned quadrotor navigation and control. These topics include: quadrotor modeling, sensor modeling, quadrotor parameter estimation, sensor calibration, quadrotor state estimation using onboard sensors, and cooperative GPS navigation. Modeling the quadrotor, sensor modeling, and parameter estimation are essential components for quadrotor navigation and control. This thesis investigates prior work and organizes a wide variety of models and calibration methods that enable indoor unmanned quadrotor flight. Quadrotor parameter estimation using a particle filter is a contribution that extends current research in the area. This contribution is novel in that it applies the particle filter specifically …

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A Vision-Based Relative Navigation Approach For Autonomous Multirotor Aircraft, Robert C. Leishman Apr 2013

A Vision-Based Relative Navigation Approach For Autonomous Multirotor Aircraft, Robert C. Leishman

Theses and Dissertations

Autonomous flight in unstructured, confined, and unknown GPS-denied environments is a challenging problem. Solutions could be tremendously beneficial for scenarios that require information about areas that are difficult to access and that present a great amount of risk. The goal of this research is to develop a new framework that enables improved solutions to this problem and to validate the approach with experiments using a hardware prototype. In Chapter 2 we examine the consequences and practical aspects of using an improved dynamic model for multirotor state estimation, using only IMU measurements. The improved model correctly explains the measurements available from …

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Chemoelectromechanical Actuation In Conducting Polymer Hybrid With Bilayer Lipid Membrane, Hao Zhang Apr 2013

Chemoelectromechanical Actuation In Conducting Polymer Hybrid With Bilayer Lipid Membrane, Hao Zhang

Theses and Dissertations

Biological and bio-inspired systems using ion transport across a membrane for energy conversion has inspired recent developments in smart materials. The active mechanism in bioderived materials is ion transport across an impermeable membrane that converts electrochemical gradients into electrical and mechanical work. In addition to bioderived materials, ion transport phenomenon in electroactive polymers such as ionomeric and conducting polymers produces electromechanical coupling in these materials. Inspired by the similarity in transduction mechanism, this thesis focuses on integrating the ion transport processes in a bioderived material and a conducting polymer for developing novel actuation systems. The integrated membrane has a bilayer …

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Mimicking The Mechanical Behavior Of Advancing Disc Degeneration Through Needle Injections, Jeremy S. Alsup Apr 2013

Mimicking The Mechanical Behavior Of Advancing Disc Degeneration Through Needle Injections, Jeremy S. Alsup

Theses and Dissertations

Objective - To investigate the effects of injected protease solution on the mechanical advancement of disc degeneration, and to establish test protocol for future pre-clinical validation of spinal arthroplasty devices. The hypothesis that injection of a protease into a cadaveric lumbar disc will mimic advanced degeneration mechanics was the subject of this study. Summary of Background Information - Spinal disc degeneration is a universal condition that progresses in adults due to aging, disease, or injury. Stages of disc degeneration have been categorized in cadaver specimens, with each degeneration level exhibiting characteristic changes in flexibility parameters. Spinal disc tissue can be …

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Modification Of Nanostructures Via Laser Processing, Louis Franzel Apr 2013

Modification Of Nanostructures Via Laser Processing, Louis Franzel

Theses and Dissertations

Modification of nanostructures via laser processing is of great interest for a wide range of applications such as aerospace and the storage of nuclear waste. The primary goal of this dissertation is to improve the understanding of nanostructures through two primary routes: the modification of aerogels and pulsed laser ablation in ethanol. A new class of materials, patterned aerogels, was fabricated by photopolymerizing selected regions of homogeneous aerogel monoliths using visible light. The characterization and fabrication of functionally graded, cellular and compositionally anisotropic aerogels and ceramics is discussed. Visible light was utilized due to it’s minimal absorption and scattering by …

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Investigation Of Surface Properties For Ga- And N-Polar Gan Using Scanning Probe Microscopy Techniques, Josephus Daniel Ferguson Iii Apr 2013

Investigation Of Surface Properties For Ga- And N-Polar Gan Using Scanning Probe Microscopy Techniques, Josephus Daniel Ferguson Iii

Theses and Dissertations

Because the surface plays an important role in the electrical and optical properties of GaN devices, an improved understanding of surface effects should help optimize device performance. In this work, atomic force microscopy (AFM) and related techniques have been used to characterize three unique sets of n-type GaN samples. The sample sets comprised freestanding bulk GaN with Ga polar and N polar surfaces, epitaxial GaN films with laterally patterned Ga- and N-polar regions on a common surface, and truncated, hexagonal GaN microstructures containing Ga-polar mesas and semipolar facets. Morphology studies revealed that bulk Ga-polar surfaces treated with a chemical-mechanical polish …

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A Methodology For The Extraction Of Design Principles For Unfamiliar Markets, Robert D. Campbell Apr 2013

A Methodology For The Extraction Of Design Principles For Unfamiliar Markets, Robert D. Campbell

Theses and Dissertations

Successful product design focuses on design principles that are relevant to a target market. Consequently, the better these principles are understood and used, the higher the likelihood that resulting products will be well-received in that market. This thesis presents a method for extracting market-specific design principles for any market. The method employs user/designer-described characteristics of products within a market to extract the design principles specific to that market. The method generalizes the product characteristics, seeks to discover design decisions that could have resulted in those characteristics, and then extracts the underlying design principles. To demonstrate the ability of the method …

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Missing Data In The Relational Model, Marion Morrissett Apr 2013

Missing Data In The Relational Model, Marion Morrissett

Theses and Dissertations

This research provides improved support for missing data in the relational model and relational database systems. There is a need for a systematic method to represent and interpret missing data values in the relational model. A system that processes missing data needs to enable making reasonable decisions when some data values are unknown. The user must be able to understand query results with respect to these decisions. While a number of approaches have been suggested, none have been completely implemented in a relational database system. This research describes a missing data model that works within the relational model, is implemented …

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The Mechanotransduction Of Primary Cilia In Tumor Progression Of Lung Adenocarcinoma, Sagar Patel Apr 2013

The Mechanotransduction Of Primary Cilia In Tumor Progression Of Lung Adenocarcinoma, Sagar Patel

Theses and Dissertations

The objective of this study was to investigate primary cilia and their mechanotransduction role in lung adenocarcinoma tumor progression. The main focus investigated the effect of primary cilia on cell cycle progression, survival, adhesion and migration analysis of these cells and the role of sonic hedgehog signaling pathway in mechanotransduction. Human Non-Small Cell Lung Cancer (NSCLC) adenocarcinoma biopsies contain more primary cilia than non-tumor lung sections. To observe the effects of primary cilia presence in lung cancer cells in-vitro, formation of primary cilia is inhibited using small interfering RNA. A549 cells with intact primary cilia observe less cell cycle progression …

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Fully Compliant Mechanisms For Bearing Subtraction In Robotics And Space Applications, Ezekiel G. Merriam Apr 2013

Fully Compliant Mechanisms For Bearing Subtraction In Robotics And Space Applications, Ezekiel G. Merriam

Theses and Dissertations

Robotics and space applications represent areas where compliant mechanisms can continue to make a significant impact by reducing costs and weight while improving performance. Because of the nature of these applications, a common need is for bearing replacement mechanisms, or mechanisms that perform the function of a bearing without the complexity and failure modes associated with bearings. Static balancing is a design strategy that attempts to reduce the actuation effort of a mechanism, and has been applied to compliant mechanisms in some applications. Monolithic construction, especially by means of 3D printing technology, is a strategy whereby the mechanism links and …

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Orthogonal Expression Of Metabolic Pathways, George Howard Mcarthur Iv Apr 2013

Orthogonal Expression Of Metabolic Pathways, George Howard Mcarthur Iv

Theses and Dissertations

Microbial metabolism can be tailored to meet human specifications, but the degree to which these living systems can be repurposed is still unknown. Artificial biological control strategies are being developed with the goal of enabling the predictable implementation of novel biological functions (e.g., engineered metabolism). This dissertation project contributes genetic tools useful for modulating gene expression levels (extending promoters with UP elements) and isolating transcription and translation of engineered DNA from the endogenous cellular network (expression by orthogonal cellular machinery), which have been demonstrated in Escherichia coli for the production of lycopene, a 40-carbon tetraterpene carotenoid with antioxidant activity and …

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Improved Channel Probing For Secret Key Generation With Multiple Antenna Systems, Britton T. Quist Apr 2013

Improved Channel Probing For Secret Key Generation With Multiple Antenna Systems, Britton T. Quist

Theses and Dissertations

Establishing secret keys from the commonly-observed randomness of reciprocal wireless propagation channels has recently received considerable attention. In this work we propose improved strategies for channel estimation between MIMO or beamforming systems for secret key generation. The amount of mutual information that can be extracted from the channel matrix estimates is determined by the quality of channel matrix estimates. By allocating increased energy to channel estimation for higher gain beamforming combinations at the expense of low-gain combinations, key establishment performance can be increased. Formalizing the notion of preferential energy allocation to the most efficient excitations is the central theme of …

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