Engineering Commons^™

Analysis Of Amputee Gait Using Virtual Reality Rehabilitation Techniques, Maurissa S. D'Angelo

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This research shows promise in becoming a standard practice for long term amputee rehabilitation. Exceptional rehabilitation is not universally available to all disabled individuals due to circumstances which limit patient care such as a limited number of trained personnel, limited access to therapy in remote areas, limited patient feedback, limited visits under insurance policies and differing expertise of personnel. Providing real-time, objective feedback will help to continuously improve the quality of life of amputee individuals and provide standardized baseline techniques. The research described in this dissertation expands the use of virtual reality systems to amputee rehabilitation. A virtual reality system …

Patterns Of Dipeptide Usage For Gene Prediction, Dayananda Sagar Gangadharaiah

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As the number of complete genomes that have been sequenced continues to grow rapidly, the identification of genes regions in DNA sequence data remains one of the most important open problems in bio-informatics. Improving the accuracy of such gene finding tools by a small percentage would affect accurate predictions of many genes of an organism (Zhu et al., 2010). This thesis presents a novel approach for identifying coding regions of a genome based on dipeptide usage.

The patterns in dipeptide usage are used to discriminate between coding and non-coding DNA regions. Two sample T-tests are used as tests of significance …

Wideband, High Data Rate Ku-Band Modulator Driver Amplifier For High Reliability Spaceborne Applications, Jeremy D. Gassmann

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The increased demand for high resolution satellite imagery for government, military, and commercial applications is driving the need for high data rate, millimeter-wave transmission systems to relay imagery information to a ground-based end user. An important aspect of this system which interfaces digital information to the RF domain is the modulator driver. The current trend in miniaturization of electronics leaves systems more vulnerable to single-event radiation effects in spaceborne applications. In an effort to overcome this deficiency, a wideband, high data rate modulator driver circuit has been designed, built, and tested using only high reliability space rated electronic components. To …

Finding Cadaveric Human Head Masses And Center Of Gravity: A Comparison Of Direct Measurement To 3d Ing, Grant Corwin Roush

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Mass properties of the human head are critical elements in developing neck injury threshold criteria in acceleration and impact environments. In order to accurately simulate the dynamics of the head in impact and acceleration environments, valid mass properties data for the human head must exist.

The purpose of this study was two-fold: First, to directly measure and generate a useful data set of human head mass properties and anthropometry, and second, compare the results from the direct measurement to measurements obtained using computed tomographic (CT) analyses of the human head. Four cadaveric human heads, all male, were measured.

For the …

An Automated Approach To A 90-Nm Cmos Drfm Dssm Circuit Design, Thomas A. Hopkins

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A digital single sideband modulator (DSSM) for a digital radio frequency memory (DRFM) was designed and implemented in a commercial 90-nm radiation-hardened-by-design (RHBD) structured ASIC by Thomas Pemberton in cite{Pemberton}. This thesis synthesized the same DSSM structure in a non-hardened 90-nm commercial process and compared the synthesis results of the two for power, delay, and area. The number of I/O bits and taps in cite{Pemberton} and this thesis were purposely made high to create a large target for radiation testing. As should be expected, the RHBD DSSM reported greater power and area. However, the RHBD power models were only estimates. …

Privacy-Preserving Attribute-Based Access Control In A Grid, Sang Mork Park

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A Grid community is composed of diverse stake holders, such as data resource providers, computing resource providers, service providers, and the users of the resources and services. In traditional security systems for Grids, most of the authentication and authorization mechanisms are based on the user's identity or the user's classification information. If the authorization mechanism is based on the user's identity, fine-grained access control policies can be implemented but the scalability of the security system would be limited. If the authorization mechanism is based on the user's classification, the scalability can be improved but the fine-grained access control policies may …

A Critical Assessment Of The High Cycle Bending Fatigue Behavior Of Boron-Modified Ti-6al-4v, Casey M. Holycross

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Boron-modified Ti-6Al-4V alloys have shown increased performance in mechanical properties over unmodified alloys and are currently of interest for use in turbine engine applications. These alloys offer up to 40% increase in ultimate tensile strength, up to 30% increase in stiffness, and favorable damage characteristics while maintaining a ductility greater than 10%. These attractive properties are attributed to small additions of boron that refine the microstructure and form strong and stiff TiB whiskers. Previous research has found that these modified alloys compare favorably in fatigue. Samples machined from a powder-metallurgy forging with nominal composition Ti-6Al-4V-1B, were tested in fully-reversed bending …

Impact Of Culture And Age On The Use Of Social Networking Websites, Ramya Reddy Ponnavolu

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Social networking websites have become very popular amongst people of all ages in recent times. These websites have brought into existence a new form of data - 'User generated content'. Companies everywhere have begun to identify the potential of these sites and have commenced efforts to take advantage of the profitable opportunities available. In spite of all this, it is reasonable to say that the latent possibilities in social networking sites are yet to be fully explored. This is due to the fact that the technology is still young and research on its potential is still ongoing. The current research …

Prognosis: A Wearable System For Health Monitoring Of People At Risk, Alexandros A. Pantelopoulos

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Wearable Health Monitoring Systems (WHMS) have drawn a lot of attention from the research community and the industry during the last decade. The development of such systems has been motivated mainly by increasing healthcare costs and by the fact that the world population is ageing. In addition to that, RandD in WHMS has been propelled by recent technological advances in miniature bio-sensing devices, smart textiles, microelectronics and wireless communications techniques. These portable health systems can comprise various types of small physiological sensors, which enable continuous monitoring of a variety of human vital signs and other physiological parameters such as heart …

Computer-Based Skeletal Age Assessment Using Hand/Wrist Radiographs In Children 8-18 Years Old, Zhihong Ni

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Children's skeletons mature at different rates, and they can be affected by a variety of factors including disease, hormone imbalance or genetics. The assessment of skeletal maturity is a frequently performed procedure that allows the detection of hormonal, growth or genetic disorders. Several methods have been developed to estimate skeletal maturity. Most methods evaluate hand/wrist radiographs using indicators such as the ratios of various bone widths, the onset of the ossification of epiphysis and epiphyseal-diaphyseal fusion. Among those methods, the FELS method differs from others in the application of different grades to each indicator and the provision of a confidence …

Adaptive Thresholding For Detection Of Radar Receiver Signals, Stephen R. Benson

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Digital microwave receivers play a critical role in many of today's modern radar tracking systems. The need for these digital receivers to push the boundaries in terms of bandwidth and input dynamic ranges (DR) is vital for their use in radar signal tracking. Significant research has been conducted in the area of the fast Fourier transform (FFT) to aid in continuing to enhance the performance capabilities of digital microwave receivers. However, with the advancement and increased complexity of these systems, the need for an efficient and effective adaptive thresholding technique is becoming ever more present.

The proposed adaptive thresholding technique …

Risk Quantification And Reliability Based Design Optimization In Reusable Launch Vehicles, Jason Maxwell King

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Due to the inherent natural variability of parameters with reusable launch vehicles, design considerations without use of a reliability or safety index may be unreliable and vulnerable to vehicle failures. Generally in preliminary air vehicle design little information is known regarding design variable uncertainties, consequently requiring a technique that can quantify epistemic uncertainties. Evidence Theory is employed to accomplish this task resulting in a reliability bound of belief and plausibility. Due to the discontinuous nature of the belief and plausibility function it is necessary to implement a continuous function known as plausibility decision to be used to calculate sensitivities that …

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

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

Design And Validation Of A Sensor Integration And Feature Fusion Test-Bed For Image-Based Pattern Recognition Applications, Hrishikesh Karvir

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We integrated a sensor hardware test-bed using scientific grade, commercial off-the-shelf (COTS) technology and developed supporting software to enable rapid prototyping. The validity of this test-bed and associated software was demonstrated through the delivery of a ground-based multispectral visual surveillance prototype for improvised explosive devices (IED) detection using electro-optical (EO) and short-wave infrared (SWIR) cameras. Software developed to support the test-bed included modules for image acquisition, preconditioning, segmentation, feature extraction, data regularization and pattern recognition. To provide spatially co-aligned data, we optimized a mutual information-based image registration algorithm to improve its convergence rate and benchmarked it against the established simplex …

Aircraft Gearbox Dynamics Subject To Electromechanical Actuator Regenerative Energy Flow, Matthew S. Rutledge

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To increase reliability and efficiency, standard aircraft components are being replaced with more electric subsystems aimed to reduce weight, conserve space, and improve energy management. One application of this process replaces standard hydraulic actuators used in flap or aileron movements with electromechanical actuators powered by an external generator. During different types of return movements, the electromechanical actuator will produce regenerative power that flows back through the generator and pulses into the engine-gearbox subsystem. The regenerative power, defined by characteristic amplitude, frequency, and other pulse attributes, coupled with the driving force produced by the engine may dramatically impact the performance and …

Surface Modification Of Carbon Structures For Biological Applications, Elizabeth Irene Maurer

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Carbon substrates have a wide variety of applications, many of which are enabled by appropriate surface modifications. In particular, the use of carbon-based substrates for biological devices can be quite advantageous due to their relative inertness and biocompatibility. Moreover, graphitic carbon can take many forms ranging from flat sheets to foams, fibers, and nanotubes. In this project, larger carbon substrates such as microcellular foam and flat graphite have been modified with carbon nanotubes, and their potential use in two types of biological applications was tested. The first study involved an investigation of the growth and proliferation of osteoblast cells on …

Simulating 3d With Mono Video, James J. Hooker

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There are different techniques to manipulate certain characteristics within mono videos to create a 3D effect when rendered and viewed. One is to display a selected frame to one eye and a different frame to the other eye so that movement of scene parts on the retina between different frames is interpreted by the viewer as visual disparity and, as a result, creates a 3D scene. Testing using StereoDisplay, a custom developed application using this technique, showed that it is effective in providing a 3D effect with some videos. Motion of the camera is required for a 3-D effect, restricting …

Design And Evaluation Of An Audio-Frequency Transresistance Amplifier For Magnetic Tape Playback, Thomas R. Salvatierra

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Analog magnetic tape remains a medium of choice for high-fidelity sound recording and reproduction. Some of this fidelity is sacrificed during the tape playback process; an optimized playback preamplifier is therefore critical to the performance of the medium. Existing playback methods integrate the voltage generated across the reproduce head to obtain a signal directly proportional to the remanent magnetic flux of the tape. An alternate playback method proposes the use of a transresistance amplifier to convert flux-proportional reproduce head current directly to voltage. This eliminates the need for voltage integration and minimizes the amount of equalization performed upon playback. Circuit …

Computational Study Of Direct Fuel Injection In The Rotax 914 Engine, Brad Pollock

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Direct injection spark ignition (DISI) is a fuel delivery method in which the fuel is introduced directly into the combustion chamber of an internal combustion engine. Although direct fuel injection was first pioneered in the early 1920's, it has only recently become a reliable option due to advances made in control systems and injection technology. Direct injection enables increased fuel efficiency and higher power output than a conventional Port Fuel Injection (PFI) system. By delivering pressurized fuel directly into the cylinder, the degree of fuel atomization and the fuel vaporization rate are increased. Hence, the air/fuel mixture can be more …

Use Of Web-Based Lessons Of Statistical Concepts With Graphics And Animation To Enhance The Effectiveness Of Learning, Lavanya Pillala

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Statistics is of critical importance to engineers. However, many engineering students struggle to grasp the meaning of statistical concepts and the idiosyncrasies of statistical methodologies. Because of this problem, instructors of statistics are constantly searching for better ways to help students understand statistical concepts. The goal of this project is to design and develop web-based lessons that use graphics and animations to enhance the effectiveness of students' learning of statistical concepts.

Lessons of three important statistical concepts have been developed for this thesis - normal distribution, central limit theorem and confidence & tolerance intervals - following well-recognized instructional design development …

Hyperspectral Methods Of Determining Grit Application Density On Sandpaper, Lee A. Clark

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A low cost real time method of determining the density of grit applied to sandpaper does not currently exist. This thesis will explore three methods for determining grit density from digital image data. A means to characterize the application in terms of frequency by using direct cosine transform basis images will be explored. An RX detector algorithm to characterize the image background will be tested. A linear unmixing methodology will be developed that characterizes the proportion of glue and grit present in each hyperspectral pixel vector.

Evolution And Analysis Of Neuromorphic Flapping-Wing Flight Controllers, Sanjay Kumar Boddhu

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The control of insect-sized flapping-wing micro air vehicles is attracting increasing interest. Solution of the problem requires construction of a controller that is physically small, extremely power efficient, and capable. In addition, process variation in the creation of very small wings and armatures as well as the potential for accumulating damage and wear over the course of a vehicle's lifetime suggest that controllers be able to self-adapt to the specific and possibly changing nature of the vehicles in which they are embedded. Previous work with Evolvable Hardware Continuous Time Recurrent Neural Networks (CTRNNs) as applied to adaptive control of walking …

The History, Philosophy, And Practice Of Agent-Based Modeling And The Development Of The Conceptual Model For Simulation Diagram, Brian L. Heath

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This research advances ABM as a generic analysis tool such that ABM can reach its full potential as a revolution in modeling and simulation. To achieve this goal, the field of ABM is examined from many perspectives. The first perspectives examined are complex systems, the historical emergence of ABM, and philosophical issues related to ABM. These topics establish some clear foundations for the field across multiple disciplines. Next the current practice of ABM is investigated. Through a comprehensive 279 article survey some current deficiencies and opportunities in ABM are identified. Based on these opportunities, a new diagramming technique called the …

Characterization Of Internal Wake Generator At Low Reynolds Number With A Linear Cascade Of Low Pressure Turbine Blades, Chase A. Nessler

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Unsteady flow and its effects on the boundary layer of a low pressure turbine blade is complex in nature. The flow encountered in a low pressure turbine contains unstructured free-stream turbulence, as well as structured periodic perturbations caused by upstream vane row wake shedding. Researchers have shown that these conditions strongly influence turbine blade performance and boundary layer separation, especially at low Reynolds numbers. In order to simulate these realistic engine conditions and to study the effects of periodic unsteadiness, a moving bar wake generator has been designed and characterized for use in the Air Force Research Labs low speed …

A Novel Synergistic Diagnosis Methodology For Identifying Abnormalities In Wireless Capsule Endoscopy Videos, Alexandros Karargyris

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Wireless Capsule Endoscopy (WCE) is a new technology that allows medical personnel to view the gastrointestinal (GI) mucosa. It is a swallowable miniature capsule device the size of a pill that transmits thousands of screenshots of the digestive tract to a wearable receiver. When the procedure finishes the video is uploaded to a workstation for viewing. Capsule Endoscopy has been established as a tool to identify various gastrointestinal (GI) conditions, such as blood-based abnormalities, polyps, ulcers, Crohn's disease in the small intestine, where the classical endoscopy is not regularly used.

As of 2009 the market is dominated by Given Imaging …

Design And Development Of A Wireless Data Acquisition System For Fall Detection, Anoop Hanchinamane Ramakrishna

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With the mortality rate of the elderly on the rise due to fall related incidents, fall detection has become an important entity in the geriatric health care sector. The study conducted in this thesis involved the design and development of a Wireless Data Acquisition System (WDAS) with Bluetooth capabilities interfaced to pulse width modulated gyroscopic sensors. Each sensor used has a reference output pulse width which changes when rotated about its sensitive axis.Part of the effort involves the design and development of two versions of printed circuit boards for the application. Each board includes a Parallax Propeller micro- controller in …

Sulfur-Tolerant Catalyst For The Solid Oxide Fuel Cell, Bozeman Joe Frank Iii

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JP-8 fuel is easily accessible, transportable, and has hydrogen content essential to solid oxide fuel cell (SOFC) operation. However, this syngas has sulfur content which results in a poisonous hydrogen sulfide that degrades electrochemical activity and causes complete SOFC failure in some cases. The goal is to synthesize and verify a cost-effective, catalyst supported on cerium oxide that either stabilizes ionic conductivity in the presence of hydrogen sulfide and/or is highly sulfur-resistant. After thorough computational analysis, it was concluded that the platinum-copper skin catalyst was the most cost-effective, sulfur-resistant catalyst. Experimental synthesis of copper, platinum, and platinum-copper skin catalysts supported …

Uncertainty Quantification Of Residual Stresses Induced By Laser Peening Simulation, Hemanth Amarchinta

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Advanced mechanical surface enhancement techniques have been used successfully to increase the fatigue life of metallic components. These techniques impart deep compressive residual stresses into the component to counter potentially damage-inducing tensile stresses generated under service loading. Laser Peening (LP) is an advanced mechanical surface enhancement technique used predominantly in the aircraft industry. To reduce costs and make the technique available on a large-scale basis for industrial applications, simulation of the LP process is required. Accurate simulation of the LP process is a challenging task, because the process has many parameters such as laser spot size, pressure profile, and material …

High-Power Energy Scavenging For Portable Devices, Simon J. Tritschler

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Portable electronic devices and crafts such as unmanned aerial vehicles (UAV's) may benefit greatly from the ability to extract power from overhead distribution power lines on a temporary basis to power electronics or charge on-board batteries. However, most of the current literature on the subject of energy scavenging is focused on micropower and other small-scale applications. Several high-power energy scavenging methods are investigated here with an emphasis on relating physical sensor dimensions with output power. A novel power scavenging mechanism is introduced that shows excellent correlation between theoretical and experimental performance. In addition, a universal power supply is proposed which …

Relative Stability Of The Inner-Current Loop Of Peak Current-Mode Controlled Pwm Dc-Dc Converters In Ccm, Nisha Kondrath

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Current-mode control is a commonly adopted method of regulation for pulse-width modulated (PWM) dc-dc power converters in industry, but is not well understood. The advantages of current-mode control over the voltage-mode control include inherent overload and short circuit protection, faster response, line-noise rejection, and multiple converter paralleling. Current-mode controlled system consists of (1) an inner-current loop and (2) an outer-voltage loop, which sets the reference voltage to the inner loop. To ensure stable operation of the multi-loop converter, all the sequential loops in the circuit should be stable with sufficient degree of stability. The research in this dissertation is focused …