Digital Commons Network^™

Selective Free-Standing Through-Wafer Porous Silicon Membrane (Sftpsm) For Integrated Meta-Material Devices, Bella Liu Yao

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Meta-materials have attracted considerable attention due to their unique electromagnetic properties, such as negative permittivity (ε), negative magnetic permeability (μ), and negative index of refraction. These devices have shown broad flexibility in compact phase shifter, backward leaky-wave antenna, and high-directivity coupled-line coupler applications; however, integrated devices utilizing meta-material structures have not yet surfaced due to a lack of integration technology.

In this work, a novel concept of integrated meta-materials is presented, using free-standing porous silicon (PS) membranes of periodic magnetic wire arrays (PMWA). The free-standing PS membranes were fabricated on p-type silicon substrates through electrochemical anodization. Systematic investigations have been …

Solar-Powered Wireless Sensor Nodes With Dynamic Power Management For Indoor Use, Ethan Charles Humphrey

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Indoor environment monitoring, such as medical monitoring and home automation, is achieved through wireless sensor networks that collect data through wireless sensor nodes. These nodes are typically powered by exhaustible power sources that could be difficult or impossible to maintain regularly. A solution to the need for frequent maintenance is to collect the solar power in the environment. This project shows how collecting the solar energy in the environment can extend the lifetime of a sensor node and limit the maintenance required. Along with charging the battery with a solar panel, a dynamic power management scheme can also be implemented. …

Evaluating The E-Consult Process For Diabetes Care Delivery At An Outpatient Care Clinic, Brian M. Zoll

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The occurrence of one of the most common chronic conditions in the U.S., diabetes, is expected to rise 53% from 24 million cases in 2003 to 37 million cases in 2023. The U.S. Veterans Health Administration (VHA) is not immune to this. The VHA has experienced an $820 million increase spending on diabetes patients between 2000 and 2008. The VHA has tried to keep the growth of chronic care costs in check through improvements in patient access to care by expanding its network of community-based outpatient clinics. Other methods the VHA has used to curb chronic care spending costs are …

Effect Of A Graded Layer On The Plastic Dissipation During Mixed-Mode Fatigue Crack Growth On Ductile Bimaterial Interfaces, Craig M. Baudendistel

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An energy-based theory for predicting mode I fatigue crack growth rates in ductile metals based on the total plastic dissipation ahead of a crack tip was proposed in 2003. Since then, this theory has been extended to layered material systems that typically include mixed-mode loading and elastic/plastic mismatch. Previous research by the author first extended this theory to include a graded layer (i.e., no step change in material properties across the crack plane) with which to more accurately model a crack interface between two materials with a mismatch in plastic properties only. In the current research, the graded layer model …

Analysis Of Human Echolocation Waveform For Radar Target Recognition, Kandarp Patel

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Some blind humans have developed the remarkable capability of echolocation, similar to the type used by mammals such as the bat, dolphin and whale. This population of human has shown the ability to classify targets based on their location, size, shape and material in diverse environmental conditions simply by listening to the reflected echoes of tongue clicks generated by their mouth. To date, much of the research into human echolocation has been confined exclusively to behavioral science and the analysis is inconsistent with the approaches used in engineering. The waveforms used in current radar systems appear different to those typical …

Low Cost Open Source Modal Virtual Environment Interfaces Using Full Body Motion Tracking And Hand Gesture Recognition, Matthew J. Marangoni

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Virtual environments provide insightful and meaningful ways to explore data sets through immersive experiences. One of the ways immersion is achieved is through natural interaction methods instead of only a keyboard and mouse. Intuitive tracking systems for natural interfaces suitable for such environments are often expensive. Recently however, devices such as gesture tracking gloves and skeletal tracking systems have emerged in the consumer market. This project integrates gestural interfaces into an open source virtual reality toolkit using consumer grade input devices and generates a set of tools to enable multimodal gestural interface creation. The AnthroTronix AcceleGlove is used to augment …

Investigation Of The Utility Of Center Frequency In Electroencephalographic Classification Of Cognitive Workload Transitions, Jones Melissa

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Successful classification of human cognitive workload is a vital component in identifying and avoiding potential performance deficits resulting from operator work overload. Previous research suggests that electroencephalogram (EEG) derived features, including center frequency, provide a robust signal which may be used to obtain highly accurate workload classification. The purpose of this work is to investigate evidence of physiological hysteresis and determine if center frequency improves a classifier's ability to correctly identify workload level. Results confirmed that including spectral data creates the most robust feature sets, while center frequency across all bands is equally reliable for classifying workload in the case …

The Effects Of Text And Hybrid Graphic-Text Formats On Pilot Performance Using Flight Deck Data Communication Displays, Ricardo Daniel Muñoz Da Costa

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Air Traffic has shown a steady increase since the institution of commercial aviation in the first quarter of the last century, and the use of the United States National Airspace System (NAS) is expected to increase by 45 percent more passengers by the year 2015 (Smith, 2004). The increasing demands of the NAS require preventive measures in order to preserve the safety of operations. NextGen is a transformative program expected to enhance the safety and effectiveness of NAS operations. One of the ways that it will achieve these goals is by improving air-ground communications.

In the current system, communications between …

Enhancing Herbicide Efficacy On Reed Canary Grass (Phalaris Arundinacea) By Testing A Plant Growth Hormone, Application Times, And Herbicide Type, Denise Lynn Fong

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Phalaris arundinacea, also known as reed canary grass (RCG), is a non-native invasive grass that thrives in floodplains. RCG plants displace native flora which reduces diversity in otherwise species rich wetlands. This is a widespread problem throughout many parts of the USA. RCG can grow by its seeds or its rhizomes. Its seeds are capable of surviving long periods in soil. RCG can potentially be controlled by multi-year treatments in early spring and early fall with broad spectrum or grass specific herbicides. The goal of this study was to optimize methods to control RCG, in order to increase species …

Hpai H5n1: A Global Pandemic Concern, With Implications For Pandemic Preperation And Public Health Policy, Lauren M. Koontz

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Research on highly pathogenic avian influenza A (HPAI) H5N1 has gained much attention in recent years due to its devastating impact within the bird population. While transmission to humans is rare, infections are fatal in more than half of the cases. One of the main concerns among the scientific community is the ability for this virus to mutate in a way much like seasonal influeanza that would allow it to be transmitted efficiently among the human population. Two researchers were able to separately create mutant isolates of H5N1 influenza A virus that could be transmitted via the respiratory route between …

Software-Defined Radio Based Blind Hierarchical Modulation Detector Via Second-Order Cyclostationary And Fourth-Order Cumulant, Yang Qu

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Modulation detection is very important to many communication and electronic warfare applications. Recent developments in cognitive radio (CR) and dynamic spectrum access (DSA) network have also brought much attention to modulation detection of unknown radio frequency (RF) signals. It is well known that using second-order cyclostationary features, e.g., spectral correlation function (SCF) and spectral coherent function (SOF), BPSK modulation can be easily distinguished from higher order modulations such as QPSK and QAM modulations. However, QPSK and higher order modulations exhibit similar second-order cyclostationary features, thus these features cannot be employed to distinguish among higher order modulations. To classify higher order …

Non-Contact Probes For Characterization Of Thz Devices And Components, Mads Jacob Hedegaard Larsen

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One of the challenges in developing semiconductor devices and integrated circuits for the terahertz (THz) region is their electrical characterization. The most common technology for their characterization is presently metal-to-metal, DC-coupled contact probes, which operate up to 750 GHz but are expensive and fragile.

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In this Master's Thesis, we investigate through numerical simulation and analysis the electromagnetic properties of a novel, AC-coupled probe. The new probe couples radiation from the device or circuit-under-test (DUT) via polarization current, which is then transformed to conduction current in the probe and down-converted in frequency to baseband by an optically-pumped photomixer. Finite-element simulations …

The Effectiveness Of Pilot Response To Generate Concatenated Downlink Messages After Evaluation Of Hybrid Graphic-Text Clearances, Steven Brent Kiss

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Data-Link Communication, or DataComm, is a digital text messaging system providing a means of communication between Air Traffic Control (ATC) and pilots. Current Pilot/ATC communication is via voice radio, but the number of ATC operators and voice channels are finite, which limits the number of aircraft voice transmission can accommodate. The number of aircraft within the National Airspace System (NAS) is expected to double between 2004 and 2025, and a transition from voice to DataComm is a necessity. DataComm is an integral part of the NAS and is implemented in incremental phases increasing its functions and capability. There are many …

Quantitative Analysis Of The Polarity Reversal Pattern Of The Earth's Magnetic Field And Self-Reversing Dynamo Models, Patrick Shane Craig

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The geologic record documents that the Earth's magnetic field has reversed 284 times over the past 160 Myr. This study uses two methods to analyze the scaling properties of the pattern of geomagnetic reversals and to analyze the scaling properties of reversals output by two mathematical self-reversing dynamo models, the Rikitake (1958) two-disk dynamo and the magnetohydrodynamic (MHD) model of Driscoll and Olson (2011). The first analysis method plots the duration versus cumulative probability for geomagnetic polarity intervals ranging between 0.01 and 35 Myr. The Kolmogorov-Smirnov statistic is used to determine the optimal minimum value of xmin at which power …

A Semantic Situation Awareness Framework For Indoor Cyber-Physical Systems, Pratikkumar Desai

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Recently, the domain of cyber-physical systems (CPSs) has emerged as a successor to the traditional embedded systems and the wireless sensor networks. The relatively new cyber-physical domain offers tight integration of control, communication and computation components to develop advanced web based application in various heterogeneous domains such as health care, disaster management, automation and environment monitoring. The applications of indoor CPSs include remote patient monitoring, smart home, etc. with focus on situation awareness via event identification from context information. The principal challenges associated with the development of situation awareness applications include uncertainty in contextual data, incomplete domain knowledge, interoperability between …

Characterization Of Stimulation-Induced Volume Changes In The Ca1 Region Of Rat Hippocampus Slices, Amanda Brooke Gutwein

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Intrinsic optical signals (IOS) were used to evaluate volume regulation mechanisms during Schaffer collateral stimulation-induced volume changes in hippocampal slices. The effects of stimulation frequency, synaptic function, ionotropic glutamate receptor (iGluR) activation, glutamate uptake, and volume regulatory anion channels (VRAC) were examined with IOS. Data were analyzed using ANOVA with Dunnett's post hoc test (p<0.05 indicated significance). IOS changes were stimulation frequency dependent between 1 Hz and 10 Hz with full recovery of IOS within 5 min. Synaptic blockage reduced the rate of swelling by 81% compared to the control and the IOS did not fully recover. Recovery rate was reduced with iGluR inhibition. Inhibition of glutamate uptake reduced the rate of swelling by 70% compared to vehicle controls. During stimulation, action potentials, iGluR activation, and glutamate uptake contribute to swelling. Regulatory volume mechanisms during stimulation were glutamate-mediated via iGluRs and VRAC independent.

Palaeoecological Analysis Of The Decline In Stromatolite Abundance During The Ordovician Period, Noran Mhm El-Sherif

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A stromatolite is a laminated benthic microbial deposit. Its uniqueness arises from being present since the Precambrian to the present. Stromatolites recorded a peak time during the Mesoproterozoic, subsequently they witnessed abrupt rises and falls in abundance with the steepest decline in the Ordovician period, from which it never recovered from. There is no consensus yet regarding the reasons behind the decline of stromatolites. Thus the decline of these microbial deposits remains an enigma. Additionally, a literature gap exists regarding the reasons that specifically led to the Ordovician decline. Accordingly, the focus of this literature-based MSc. thesis is to find …

New Insights Into The Spinal Recurrent Inhibitory Pathway Normally And After Motoneuron Regeneration, Ahmed Zayed Obeidat

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Despite more than seven decades of intensive research, uncertainty is the hallmark of spinal recurrent inhibition. The simplest possible structure that is formed between the a-motoneuron and its inhibitory interneurons has been the subject of long lasting scientific debate. To date, there is no consensus on the functional significance of this circuit. Even the simplest assumption of a negative feedback loop does not hold true. The current work used the technique of in vivo intracellular recording from the adult rat a-motoneurons to study the normal function and the plasticity after nerve injury and regeneration of this simple, yet intricate spinal …

Stability Of A Fuzzy Logic Based Piecewise Linear Hybrid System, Aaron W. Seyfried

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Complex cyber-physical systems are difficult to model and control. However, humans are capable of accomplishing these tasks by constantly adapting and redefining the rules to control these complex systems. Fuzzy logic provides a means of encoding human inference into a control methodology. However, the fuzzy logic controllers are nonlinear and their stability is difficult to verify. Therefore, the widespread usefulness of fuzzy logic controllers is limited. It has been proven that fuzzy logic controllers can be implemented as piecewise linear switched controllers. It has also been shown that the piecewise linear system can be implemented as a hybrid system. Piecewise …

Integrity Monitoring For Multiple Errors In Vision Navigation Systems, Nicholas Allen Baine

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In aviation applications, navigation integrity is paramount. Integrity of GPS systems is well established with set standards. Vision-based navigation systems have been found to be an adequate substitute for GPS when it is unavailable but are unlikely to be utilized until there is a measure for system integrity. Work has been done to detect the effect of a single measurement pair being corrupted with a bias; however, the measurement geometry varies greatly with the environment. The environment could be sparse in visual features to track, or the environment could be rich with features. With more features, there is a greater …

Religious Fundamentalism Vs. Security: What Really Drives Likud's Policies Towards Israeli Settlements?, Claudio Vinicius Santo

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This research challenges the general claim that religious fundamentalist groups exercise great influence in Israeli policies regarding settlements in the Palestinian disputed territory. It proposes an alternate hypothesis that security considerations, rather, are the driving factors underlying the government's decision process. These two propositions are evaluated by assessing three settlement decisions made under a Likud led government - a common factor purposely chosen given the known symbiotic relation between religious fundamentalist groups and the Likud's right wing political movement. Upon assessing the return of Sinai to Egypt, the annexation of the Golan Heights, and the unilateral disengagement from Gaza Strip, …

Bull's-Eye Structure With A Sub-Wavelength Circular Aperture, Masoud Zarepoor

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This research focuses on improving the spatial resolution of terahertz (THz) imaging. Using a sub-wavelength aperture in a metal ground plane is the most common way to improve the spatial resolution, but a sub-wavelength aperture has low radiation transmission. To increase the radiation transmission of a sub-wavelength aperture, periodic circular grooves were put in the metal around the aperture. The sub-wavelength circular aperture and the periodic circular grooves around it are known as the bull's-eye structure. The bull's-eye structure shows high radiation transmission at its design frequency, and it also has sub-wavelength spatial resolution. This research designed the bull's-eye structure …

Abiotic Degradation Of Chlorinated Hydrocarbons (Chcs) With Zero-Valent Magnesium (Zvm) And Zero-Valent Palladium/Magnesium Bimetallic (Pd/Mg)-Reductant, Fang Yu

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Chlorinated hydrocarbons (CHCs) in groundwater can be treated by monometallic and bimetallic metal reductants through abiotic degradation. The breakdown of CHC is achieved by gaining electrons from those reductants and removing chlorines from CHC molecules to transform the CHCs into less chlorinated compounds. As a proven technology in groundwater treatment, permeable reactive barriers (PRBs) have been used to passively treat contaminated groundwater, in which granular metals can be used as reactive materials. This study explored the abiotic degradation of CHCs by zero-valent magnesium (ZVM) and bimetallic palladium/magnesium (Pd/Mg) reductants. Different CHCs (carbon tetrachloride, chloroform, dichloromethane (DCM), 1,2-dichloroethane (1,2-DCA), 1,1,2-trichloroethane (1,1,2-TCA), …

Impact Of Binaural Beat Technology On Vigilance Task Performance, Psychological Stress And Mental Workload, Elizabeth Ann Shoda

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Currently, there is only one published study examining the impact of binaural beats on the performance of a laboratory vigilance task, however this study had mixed results and left many questions unanswered. I further examined this phenomenon by using a successive vigilance task, between-subjects design, and a control condition to determine whether beta frequency binaural beats could affect vigilance performance over time and across conditions. I hypothesized that participants listening to beta binaural beats would have more hits and fewer misses on the vigilance task than participants in the control condition. In addition, I hypothesized that participants listening to beta …

Long-Term Effects Of Deer Browsing On Northern Wisconsin Forest Plant Communities, Danielle Rae Begley

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The effects of excessive white-tailed deer (Odocoileus virginianus) browsing on forest understory plant communities are well-documented. However, these studies are usually short-term, and fail to focus on phylogenetic diversity and additional variables that may explain species composition. This study examined ecological and phylogenetic diversity, vegetation structure, and light (% insolation) in short (7 year) and long-term (22 year) exclosures (and paired controls) to identify if competitive exclusion occurs in long-term exclosures. A deer browsing susceptibility index (DBS) was also developed to identify species reliant on exclosures for persistence. Statistical analysis using 2-way ANOVAs showed increased percent cover, vegetation height, and …

The Effects Of Multicollinearity In Multilevel Models, Patrick Carl Clark Jr.

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This study examined a method for calculating the impact of multicollinearity on multilevel modeling. The major research questions concerned a) how the simulation design factors affect (multilevel variance inflation factor) MVIF, b) how MVIF affects standard errors of regression coefficients, and c) how MVIF affects significance of regression coefficients. Monte Carlo simulations were conducted to address these questions. Predictor relationships were manipulated in order to simulate multicollinearity. Findings indicate that a) increases in relationships among Level 1 predictors and also relationships among Level 2 predictors led to increased MVIF for those specific variables, b) as MVIF increases for a predictor, …

Structural-Acoustic Analysis And Optimization Of Embedded Exhaust-Washed Structures, Ryan N. Vogel

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The configurations for high speed, low observable aircraft expose many critical areas on the structure to extreme environments of intense acoustic pressure loadings. When combined with primary structural and thermal loads, this effect can cause high cycle fatigue to aircraft skins and embedded exhaust system components. In past aircraft design methods, these vibro-acoustic loads have often been neglected based on their relatively small size compared to other thermal and structural loads and the difficulty in capturing their dynamic and frequency dependent responses. This approach is insufficient for effective advanced designs of complex aerospace structures, such as internal ducted exhaust systems …

Tolfenamic Acid Induces Cell Apoptosis And Inhibits Collagen Accumulation In Keloid Fibroblasts, Dan Yi

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Keloid scar is a fibroproliferative disorder which results from the accumulation of collagen through the activation of TGF-B/Smad signaling. Tolfenamic acid (TA) has been found to inhibit collagen synthesis in animal and induce cancer cell apoptosis. In this study, we investigated the effect of DMSO on cell apoptosis, TA on collagen deposition, and TA on collagen type I and smad2 protein expression in human normal fibroblasts (NFs) and human keloid fibroblasts (KFs). In the dose- and exposure time- response assays, we found that 1% DMSO for 48h treatment did not obviously induce NF and KF apoptosis and that 0.55x10-3 M …

Dual-Stimuli Responsive Poly(Ethylenimine)S With A Tunable Lcst For Gene Delivery, Mary Abraham

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Hyperbranched poly(ethylenimine)s (HPEI) were modified with hydrophobic isobutyryl amide groups (HPEI-IBAm_0.60) to cause an LCST. These modified polymers were then further substituted with hydrophobic alkyl chains (HPEI-IBAm_0.60-R_0.40), a mixture of alkyl chains and hydroxyethyl groups (HPEI-IBAm_0.60-EtOH_0.20-R_0.20), and a mixture of alkyl chains and low molecular weight PEG (HPEI-IBAm_0.60-PEG_0.20-R_0.20) to determine the effect of different functional groups on solubility behavior. At pH 7.4, all but three LCSTs were below body temperature (37 °C), while at pH 5, all but three LCSTs were above …

Spatialized Audio And Landmarks In Team Navigation, Andrew Hampton

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Using data collected from a prior study that established the benefit of spatialized audio on team navigation, the current paper examines the underlying mechanisms by which that benefit arose. With linguistic measures extracted from trial transcripts, I study emergent patterns of conversation for four dyads as they attempt to rendezvous in an immersive virtual environment. Spatialized audio is compared to landmarks, traditionally viewed as integral to navigation tasks, on the basis of coordination and strategy. Analyses reveal that spatialized audio creates a decreased need to speak overall. Paired with the performance advantage, this creates a more linguistically efficient task structure. …