Engineering Commons^™

An Improved Genetic Algorithm For Knapsack Problems, Taskiran, Gamze Kilincli

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In this study, an improved genetic algorithm (GA) is presented to solve the multidimensional 0-1 knapsack problem (MKP). The MKP is a well-known combinatorial optimization problem and has received wide attention from the operations research community for decades. Although recent advances in computing and optimization technologies have made the solution of small and medium size instances possible, this NP-hard problem, in general, still remains one of the challenging problems yet to be solved.

Of the various algorithms developed to solve the MKP, GA seems to be one of the best methods pointed out in the literature. A GA is an …

The Harmonic Distortion Reduction Of Phase-Angle Fired Scrs Feeding A Resistive Load Using Fuzzy Logic, Matthew A. Clark

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High power silicon controlled rectifiers (SCR) are used in the application of infrared radiation testing. A case study has been performed on a department of defense facility utilizing SCRs to transfer electrical energy to thermal energy. The facility is capable of generating up to 5000 °F across large cross-sectional areas, requiring tens of megawatts of power. The combination of high power, unbalanced loads, and SCR switching generate high harmonic disturbances that offer significant challenges for conventional linear control systems. In addition, unbalanced three-phase distribution systems are difficult to model, specifically during switching transients. Fuzzy logic is used to characterize the …

Population Fit Threshold: Fully Automated Signal Map Generation For Baseline Correction In Nmr-Based Metabolomics, Daniel C. Homer

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Baseline correction of NMR-based metabolomic spectra is a key step in data processing to elucidate biomarkers of diseased and toxic states. Automated baseline correction methods often use human-selected parameters. Presented is a method for automated baseline correction using parameters selected from and without manipulation of the spectrum. The focus is on generating an accurate signal map based on the differentiating characteristics of baseline noise and signal. The presented method of signal map generation and baseline correction was developed and tested on 13C and 1H NMR spectra. The spectra were as simple as chemical standards containing less than 25 signal peaks …

Mining Shared Decision Trees Between Datasets, Qian Han

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This thesis studies the problem of mining models, patterns andstructures (MPS) shared by two datasets (applications), a well understood dataset, denoted as WD, and a poorly understood one, denoted as PD. Combined with users' familiarity with WD, the shared MPS can help users better understand PD, since they capture similarities between WD and PD. Moreover, the knowledge on such similarities can enable the users to focus attention on analyzing the unique behavior of PD. Technically, this thesis focuses on the shared decision tree mining problem. In order to provide a view on the similarities between WD and PD, this thesis …

Induction Of P53 Dependent Cellular Senescence Through Hdmx Inhibition Or Ypel3 Expression, Kelly Lynn Robbins Miller

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Mutations in p53 that compromise its function have been reported in approximately half of all human cancers (Vousden et al., 2002). The other half of human tumors that retain wild-type p53 have a dysfunctional p53 pathway through other mechanisms (Wade et al., 2009). Activation of p53 leads to cell cycle arrest, DNA repair, apoptosis and senescence, however, the pathway leading to cellular senescence is the focus of this study. Cellular senescence is a process leading to irreversible arrest of cell division. Under normal physiologic conditions, the activity of p53 is kept in check by its negative regulators, Mdm2 and MdmX. …

Development Of An Efficient Super-Resolution Image Reconstruction Algorithm For Implementation On A Hardware Platform, Pestak Thomas C.

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There is a growing demand from numerous commercial and military applications for images with ever-improving spatial resolution. However, there are resolution-limiting factors inherent in all imaging systems. Decreasing pixel sizes and/or increasing sensor arrays are not always viable. Super-Resolution (SR) Image Reconstruction is an image processing technique that restores a high-resolution (HR) image from a series of low-resolution (LR) images of a particular scene. Recently, there has been extensive research on robust SR algorithms used for post-processing. The goal of this thesis is to explore the current SR research and design computationally efficient SR algorithms for real-time processing based on …

A Direction Finding System Using Log Periodic Dipole Antennas In A Sparsely Sampled Linear Array, Jonathan Andrew Weldon

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This thesis explores the use of wide band log periodic dipole array (LPDA) antennas in direction finding systems. A wide band log periodic antenna will be constructed and tested to ensure hardware capability. A novel approach utilizing non-uniform spacing in a linear array will be used to improve the spatial resolution of the direction finding system. These specialized linear arrays are known as minimum redundancy or non-redundant linear arrays.

A Structured Asic Approach To A Radiation Hardened By Design Digital Single Sideband Modulator For Digital Radio Frequency Memories, Thomas B. Pemberton

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Digital Radio Frequency Memories (DRFM) are widely used as modules in digital signal processing. These modules can provide several forms of signal manipulation and storage capabilities. With single event effects caused by environmental radiation the need for a radiation hardened DRFM is increased. Typical radiation hardening involves the use of specialized foundries utilizing proprietary CMOS libraries that are expensive to build or adding lead packages around a chip that is expensive and add weight to the chip. An alternative radiation hardening technique is to utilize a radiation hardened by design library. This library includes digital gates that have been hardened …

Frequency Domain Processing Based Chaos Communication For Cognitive Radio, Daniel Y. Sundersingh

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Chaotic systems are deterministic non-linear dynamical systems which have intrinsic properties such as: irregularity, aperiodicity, and are impossible to predict over long periods of time. Cognitive radio on the other hand, has emerged recently as a powerful means to tackle the spectrum congestion problem. The goal of this thesis is to combine the benefits of the chaos communication system with the cognitive radio to create a robust, highly secure, flexible chaotic cognitive radio system. We first begin with a short survey of chaotic communication and cognitive radio technology. Then we compare chaotic waveforms to other conventional PN sequences and show …

Stochastic Mistuning Simulation Of Integrally Bladed Rotors Using Nominal And Non-Nominal Component Mode Synthesis Methods, Joseph A. Beck

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Mistuning prediction in integrally bladed rotors is often done with reduced order models that minimize computational expenses. A common model reduction technique used for mistuning applications is the component mode synthesis method. In this work, two modern component mode synthesis methods are used to generate mistuned response distributions that will be used to determine if the two methods are statistically indistinguishable. The first method, nominal mode approximation, assumes an airfoil geometric perturbation alters only the corresponding substructure modal stiffnesses while its mode shapes remain unaffected. The mistuned response is then predicted by a summation of the nominal modes. The second …

Development Of A Remote Medical Image Browsing And Interaction System, Wei Ye

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In this thesis a new capability - remote image browsing built upon our existing music telepresence platform is introduced. The implementation of this new image capability has two parts: one part is the local image viewing and the other part is distributed image-view interaction. Image viewing part is realized using the foundation of Linux GTK+ library. Most popular lossless and lossy image coding formats such as GIF, PNG, BMP and JPEG are supported currently. Image viewing part also provides several image operations such as: zoom in and zoom out, image information display and moreover users can select their own regions …

A Study Of Evolvable Hardware Adaptive Oscillators For Augmentation Of Flapping-Wing Micro Air Vehicle Altitude Control, Bharath Venugopal Chengappa

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The control of insect-sized flapping-wing micro air vehicles is fraught with difficulties. Even when adequate control laws are known, limits on computational precision and floating-point processing can render it difficult to field implementations that provide sufficiently accurate and precise vehicle body placement and pose. Augmentation of an existing altitude controller with an Evolvable Adaptive Hardware (EAH) oscillator has been proposed as a means for an on-board altitude controller to correct control precision and accuracy difficulties during normal flight. This thesis examines a range of setting of the internal learning algorithms for the EAH oscillator and provides empirical evidence about which …

Cytochrome C Oxidase From Rhodobacter Sphaeroides: Oligomeric Structure In The Phospholipid Bilayer And The Structural And Functional Effects Of A C-Terminal Truncation In Subunit Iii, Teresa L. Cvetkov

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Cytochrome c oxidase (COX) of the mitochondrial electron transport chain catalyzes the reduction of oxygen to water while concomitantly translocating protons across the inner mitochondrial membrane. This two part dissertation is a structural and functional investigation of COX using the bacterial model system from Rhodobacter sphaeroides (R.sph.).

First, the oligomeric structure of R.sph. COX within the lipid bilayer was investigated using discontinuous sucrose gradient ultracentrifugation. Utilizing this technique, liposomes containing R.sph. COX (pCOV) were separated from liposomes lacking enzyme (COV). The net buffering capacity and degree of light scattering per COX molecule were reduced in pCOVs, making them well suited …

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 …

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 …

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 …

Charaterization Of Chlorpyrifos Toxicity On The Pancreatic Beta Cell Line Rinm5f, Zhongyu Yan

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Chlorpyrifos (CPF) is a well-known organophosphate (OP) insecticide that inhibits acetylcholinesterase (AChE). Organophosphates have been shown to induce hyperglycemia in both humans and animals that cannot be explained by AChE inhibition alone. Pancreatic β-cells are responsible for secreting insulin and playing a fundamental role in glucose homeostasis. The aim of this research was to investigate CPF toxicity on the insulin secreting β-cell line RINm5f (RIN). In the first part of this dissertation, we determined that cytotoxic concentrations of CPF between 50 µM and 200 µM induced a dose-dependent increase in RIN cell apoptotic and necrotic death (p<0.05). Lower doses, i.e., 5-25 µM did not induce apoptosis or necrosis. In further mechanistic studies, inhibitors of c-Jun N-terminal kinase (JNK) and P38 pathways, i.e., SP600125 and SB202190, successfully attenuated CPF-induced apoptosis (p<0.05), suggesting cell death is mediated by JNK and/or p38. In addition, N-Acetyl-L-cysteine (NAC), an antioxidant, inhibited apoptosis suggesting that oxidative stress is also involved in RIN cell death. In the second part of this dissertation, low dose CPF's effects on insulin synthesis and secretion was studied. Our results showed that RIN cells treated with CPF for 4 hr exhibited a dose-dependent decrease in insulin secretion in response to stimulation by 50 mM potassium (p<0.05). Insulin secretion stimulated by 25 mM glucose also showed significant decreases upon incubation with various doses of CPF (p<0.05). Insulin synthesis involves proteolytic cleavage of proinsulin at two specific sites. The enzymes responsible for promoting proinsulin cleavage, i.e, prohormone convertase (PC) 1/3 and 2 (PC2), contain a serine hydrolase catalytic triad, His-Asp-Ser, similar to AChE. CPF modification of PC enzymes similar to AChE, could potentially interrupt the conversion of proinsulin to insulin and disrupt insulin secretion. PC2 enzyme activity was significantly inhibited by CPF at concentrations as low as 10 µM (p<0.01). RIN cells, for the first time, were found to secrete proinsulin was through a constitutive instead of a regulated pathway. In summary, our results show that CPF not only exerts a direct cytotoxic effect at concentrations above 50 µM, but also significantly impairs insulin secretion at lower doses. Low dose CPF could potentially affect endocrine function in vivo by inhibiting the proinsulin processing enzyme PC2.

Impact Of Induced Defects On Rotor Life Assessment, Ashley Winfield Whitney-Rawls

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There is an economic need to reduce the conservatisms of current lifing methods and extend component life. Extending component usage increases the probability of failure during operation. Therefore, the risk of continued service must be quantified before life extension concepts can successfully be implemented. The current FAA approved software for the certification of new rotor designs, only accounts for defects present prior to service. Defects due to the handling of components during inspection and material fatigue will induce defects during service and need to be included in any analysis of component life extension. Component life extension analysis of an Inconel …

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 …

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 …