Physical Sciences and Mathematics Commons^™

Rapid Indirect Trajectory Optimization On Highly Parallel Computing Architectures, Thomas Antony

Open Access Theses

Trajectory optimization is a field which can benefit greatly from the advantages offered by parallel computing. The current state-of-the-art in trajectory optimization focuses on the use of direct optimization methods, such as the pseudo-spectral method. These methods are favored due to their ease of implementation and large convergence regions while indirect methods have largely been ignored in the literature in the past decade except for specific applications in astrodynamics. It has been shown that the shortcomings conventionally associated with indirect methods can be overcome by the use of a continuation method in which complex trajectory solutions are obtained by solving …

New Strategies To Reveal Protein Candidates In Protein-Protein Interactome Study, Meng-Chieh Chen

Open Access Theses

Comprehensive protein-protein interaction network analysis can help reveal protein functions in a system-wide manner. A reliable knowledgebase of interaction networks is not only important for selecting the candidates for drug therapies, but also for evaluating the disease risk. In current interaction databases, 322579 interactions comprised of 56460 proteins have been reported (statistical analysis from APID: Agile Protein Interaction DataAnalyzer; http://bioinfow.dep.usal.es/apid/index.htm). The huge datasets are contributed mainly by yeast -two -hybrid (Y2H) screening and affinity-purification followed by mass spectrometry (AP-MS). High false positive rates and failing to cover certain interaction categories are the limitations of these two methods. Here, we developed …

Nitrate Removal From Subsurface Drainage By Denitrifying Bioreactor, Erin Chichlowski

Open Access Theses

Denitrifying bioreactors are an edge-of-field best management practice that reduce nitrate in runoff and subsurface drainage waters with minimum surface foot print and management requirements. The objectives of this study included evaluating a 173 m3 wood chip bioreactor for nitrate reduction and removal rates, the effects on phosphorus, and the impacts of the bioreactor's physical characteristics on effective nitrate reduction During periods of flow, weekly water samples were collected for lab analysis of nitrate+nitrite (nitrate-N), total nitrogen (TN), soluble reactive phosphorus (SRP), and total phosphorus (TP) and measurements were made of water temperature, dissolved oxygen, pH, oxidation reduction potential, temperature, …

Impact Of License Selection On Open Source Software Quality, Benjamin J. Cotton

Open Access Theses

Open source software plays an important part in the modern world, powering businesses large and small. However, little work has been done to evaluate the quality of open source software. Two different license paradigms exist within the open source world, and this study examines the difference in software quality between them. In this thesis, the author uses technical debt as a measure of software quality. Eighty open source projects (40 from each paradigm) were downloaded from the popular open source hosting website SourceForge. Using complexity, code duplication, comments, and unit test coverage as inputs to the SonarQube technical debt model, …

Wi-Fi Real Time Location Systems, Benjamin A. Doll

Open Access Theses

This thesis objective was to determine the viability of utilizing an untrained Wi-Fi real time location system as a GPS alternative for indoor environments. Background research showed that GPS is rarely able to penetrate buildings to provide reliable location data. The benefit of having location information in a facility and how they might be used for disaster or emergency relief personnel and their resources motivated this research. A building was selected with a well-deployed Wi-Fi infrastructure and its untrained location feature was used to determine the distance between the specified test points and the system identified location. It was found …

Digital Image Correlation Of Heterogeneous Deformations In Polycrystalline Material With Electron Backscatter Diffraction, Javier Esquivel

Open Access Theses

This work establishes the ability to conduct digital image correlation (DIC) investigations at varying length scales. DIC allows for a computational method of strain field measurements using multiple images to track random speckle patterns on material surfaces. The use of a powder silicon oxide speckle allows for high optical magnification correlation using conventional load frames. Self-assembling gold nanoparticles provide sub-micron resolution speckle patterns to study microstructure influences on deformation using scanning electron microscopy. The complex microstructure in aerospace grade aluminum and nickel-based superalloys, give rise to varied deformation fields, which can be studied using electron backscatter diffraction. Specimen preparation techniques, …

Profit-Maximizing Responses To Climate Change In Commodity Agriculture: Does Adaptation Matter?, Sajeev Erangu Purath Mohankumar

Open Access Theses

Accumulation of greenhouse gases in the atmosphere has led to rising temperatures, and is expected to lead to a change in climate. Crop yields are vulnerable to these changes. Adaptation is expected to be key to combating climate change impacts, but the effectiveness of adaptation strategies is not well understood. Hence, there is a need to assess the impacts of climate change on agriculture and devise profitable adaptation strategies to combat its effects. This study uses historical and three projected climate data sets to simulate yields using the crop model Daycent, empirical relationships between weather and agronomic variables that influence …

Impact Of A Visual Programming Experience On The Attitude Toward Programming Of Introductory Undergraduate Students, Saurabh Godbole

Open Access Theses

Traditionally, textual tools have been utilized to teach basic programming languages and paradigms. Research has shown that students tend to be visual learners. Using flowcharts, students can quickly understand the logic of their programs and visualize the flow of commands in the algorithm. Moreover, applying programming to physical systems through the use of a microcontroller to facilitate this type of learning can spark an interest in students to advance their programming knowledge to create novel applications. This study examined if freshmen college students' attitudes towards programming changed after completing a graphical programming lesson. Various attributes about students' attitudes were examined …

Application Of Bayesian Networks In Consumer Service Industry, Yuan Gao

Open Access Theses

Gao, Yuan. M.S.I.E., Purdue University. December 2014. Application of Bayesian Networks in Consumer Service Industry. Major professor: Vincent G. Duffy The purpose of the present study is to explore the application of Bayesian networks in the consumer service industry to model causal relationships within complex risk factor structures using aggregate data. An analysis of the Hawaii tourism market was conducted to find out how visitor characteristics affect their behavior and experience as consumers during the trips, and influence the tourism market outcomes represented by measurable factors. Two hypotheses were proposed regarding the use of aggregate data and the influence of …

Dynamic Wireless Power Transfer System For The Unmanned Aerial Vehicles, Tae Sup Lee

Open Access Theses

UAVs have limitless applications to help our daily lives for the autonomous operations. UAVs have a limited power capacity due to weight constraints and are therefore not able to travel long distances. Ground stations for recharging UAVs throughout different points can increase the flight time of the UAVs with the current UAV battery capacity. This study investigates how the wireless charging system for the ground station can be made more robust when there are misalignments. The wireless charging system is monitored by an Arduino, micro controller, to assess the current condition of charging. The Arduino is able to change the …

High-Purity Gallium Analysis By Inductively Coupled Plasma Mass Spectrometry, Kyungjean Min

Open Access Theses

The mobility of Two-dimensional Electron Gas in AlGaAs/GaAs heterostructures that are grown in the Molecular Beam Epitaxy (MBE) can be increased by purification of the gallium used to grow the films. To attain 200 million cm2/Vs mobility, the impurity concentration of gallium should be reduced to below 1 ppb. The commercial 7N (99.99999%) gallium with 100 ppb total impurity is currently used in the MBE at Purdue University and is being purified by zone refining. To evaluate the commercial 7N gallium and establish the methodology for the impurity measurement after zone refining, germanium, iron, and zinc in 6N and 7N …

Watershed Delineation In The Field: A New Approach For Mobile Applications Using Lidar Elevation Data, Samuel Adam Noel

Open Access Theses

With the advancement of mobile devices, opportunities to take watershed management tasks out of the office and into the field can be realized. In turn, field workers can utilize these technologies to expedite the decision-making process so that they may focus on meeting with clients and addressing agricultural watershed management issues. High-resolution (∼1.5 m postspacing) elevation data gathered by light detection and ranging (LiDAR) provides the topographic detail necessary to model hydrology at the field-scale (∼1 km2).

Non-artifactual surface depressions lead to erroneous surface flow patterns when using existing algorithms. So a sequential depression-filling algorithm (SDFA) has been developed to …

Evaluating Optimum Levels Of Detail For 3d Interactive Aviation Maintenance Instructions, Nicholas Rohe

Open Access Theses

With the aviation industry shifting from paper based maintenance instructions to digital maintenance instructions, there needs to be a standard for what goes into creating the digital instructions. This study was done to determine what the optimum level of detail for 3D interactive aviation maintenance instructions. The definition of optimum for this study was: lowest amount of geometrical data with lowest rendering needed for comprehension and ease of use.

Online Simulations For Conceptual Understanding Of Thermoelectric Devices, Maria De Rosario Uribe

Open Access Theses

Computer simulations have been extensively used with educational purposes. However, the successful implementation in order to improve learning has been a matter of debate in research in education. The purpose of this case study is to analyze how a set of computer simulations can improve student understanding of thermoelectric devices. The study was developed in a learning context characterized by the advanced degree of difficulty of the topics treated, the high academic level of education of the students, and the online nature of the learning environment. As part of the course, students were provided with instructional materials that guided the …

Waste Heat Recovery Options In A Large Gas-Turbine Combined Power Plant, Ularee Upathumchard

Open Access Theses

This study focuses on power plant heat loss and how to utilize the waste heat in energy recovery systems in order to increase the overall power plant efficiency. The case study of this research is a 700-MW natural gas combined cycle power plant, located in a suburban area of Thailand. An analysis of the heat loss of the combustion process, power generation process, lubrication system, and cooling system has been conducted to evaluate waste heat recovery options. The design of the waste heat recovery options depends to the amount of heat loss from each system and its temperature. Feasible waste …

User-Differentiated Hierarchical Key Management For The Bring-Your-Own-Device Environments, Di Xie

Open Access Theses

To ensure confidentiality, the sensitive electronic data held within a corporation is always carefully encrypted and stored in a manner so that it is inaccessible to those parties who are not involved. During this process, the specific manners of how to keep, distribute, use, and update keys which are used to encrypt the sensitive data become an important thing to be considered. Through use of hierarchical key management, a technique that provides access controls in multi-user systems where a portion of sensitive resources shall only be made available to authorized users or security ordinances, required information is distributed on a …

The Indiana Cybersecurity Services Center (Incsc): A Cost-Benefit Analysis For K-12 Schools, Hans Christian Vargas Silva

Open Access Theses

The aim of this thesis is to determine if there are greater benefits than costs associated in the participation of public K-12 school corporations in the Indiana Cybersecurity Services Center (INCSC). This thesis is an ex-antecost-benefit analysis policy assessment of the INCSC. The study consisted of a sample of 6 school corporations from which 5 were classified as small and 1 was large. Three methods were considered for data collection; however conducting interviews was the most effective method due to the interaction with IT personnel from each organization in order to analyze current costs related to 4 areas of …

Liquid Swine Manure Application Timing And Instincttm Impacts On Net Soil Nitrogen Mineralization And Corn Yield, Min Xu

Open Access Theses

Nitrogen (N) is one of the most expensive variable input costs for corn production. Optimized manure management is essential to ensure maximum crop N utilization and to reduce the risk of N loss. A field study was conducted in central Indiana from 2011-2013 to assess liquid swine ( Sus scrofa L.) manure N availability when applied at different times or co-applied with InstinctTM , a microencapsulated form of nitrapyrin. Soil inorganic N contents, soil N mineralization, corn yield, grain N content, whole plant N concentrations of corn at the V6 growth stage, and ear leaf N concentrations of corn at …

Elucidating The Mechanism Of Phenylpropanoid Regulation By The Arabidopsis Mediator Complex, Wenjie Zeng

Open Access Theses

The Mediator complex is a multi-protein co-regulator of eukaryotic transcription which plays a role in the expression of many, if not most, genes of the cell. Two Mediator subunits, REF4 and RFR1, were demonstrated to be important for the normal regulation of phenylpropanoid metabolism in Arabidopsis. Phenylpropanoids are a family of specialized plant metabolites derived from the amino acid phenylalanine and are involved in defense against pathogens, UV protection and structural support. In order to understand how Mediator regulates phenylpropanoid metabolism through REF4 and RFR1, a better basic understanding of this protein complex is required. Here I provide data on …

Transformation Of Biomass Carbohydrates By Transition Metal Catalysts, Christine M Bohn

Open Access Dissertations

By selectively removing functional groups from biomass derived carbohydrates, valuable platform chemicals can be generated from renewable sources. Through dehydration chemistry glucose can be upgraded into 5-(Hydroxymethyl)-2-furfuraldehyde (HMF) and levulinic acid. Iron (III) chloride hexahydrate has shown moderate activity to transform glucose into HMF and has also shown high yields and selectivity for the production of levulinic acid. Typically synthesized from acidic solutions made with mineral acids, levulinic acid has now been produced in high yields with a metal salt. The difference between maximizing production for HMF or levulinic acid from the same catalyst relies on the control of the …

Beam-Induced Radiation Heating On The Superconducting Undulator At The Advanced Photon Source, Laura Elizabeth Boon

Open Access Dissertations

In January 2013 the Advanced Photon Source (APS), a 7 GeV synchrotron X-ray source, commissioned a Superconducting Undulator (SCU). The superconducting magnet is thermally isolated from the beam vacuum chamber, which absorbs the beam-induced heating. Previous beam induced heat load studies at other laboratories had not included a robust calculation of radiation heating from the upstream dipole magnet. The mitigation of the radiation heating mechanism, and production of photoelectrons to seed an electron cloud was studied for this thesis. ^ An analytical model was developed to predict the radiation heat load on the SCU chamber. This model was benchmarked with …

Applications Of Femtosecond Coherent Anti-Stokes Raman Scattering In Combustion, Claresta Nicole Dennis

Open Access Dissertations

The dissertation deals with the further development of chirped-probe-pulse femtosecond coherent anti-Stokes Raman spectroscopy (CPP fs-CARS) for applications of gas phase thermometry and extension to methane concentration measurements. The main effort has been to assess the usefulness and robustness of the technique in turbulent combustors of practical interest. A primary aim has been to evaluate the use of CPP fs-CARS for vibrational N₂ thermometry in a highly turbulent environment. It has been suggested that due to the laser beam temporal overlap required for fs-CARS signal generation, the technique would be unsuccessful due to beam propagation retardation effects from density …

On The Occurrences Of Motifs In Recursive Trees, With Applications To Random Structures, Mohan Gopaladesikan

Open Access Dissertations

In this dissertation we study three problems related to motifs and recursive trees. In the first problem we consider a collection of uncorrelated motifs and their occurrences on the fringe of random recursive trees. We compute the exact mean and variance of the multivariate random vector of the counts of occurrences of the motifs. We further use the Cramér-Wold device and the contraction method to show an asymptotic convergence in distribution to a multivariate normal random variable with this mean and variance. ^ The second problem we study is that of the probability that a collection of motifs (of the …

Secure Platforms For Enforcing Contextual Access Control, Aditi Gupta

Open Access Dissertations

Advances in technology and wide scale deployment of networking enabled portable devices such as smartphones has made it possible to provide pervasive access to sensitive data to authorized individuals from any location. While this has certainly made data more accessible, it has also increased the risk of data theft as the data may be accessed from potentially unsafe locations in the presence of untrusted parties. The smartphones come with various embedded sensors that can provide rich contextual information such as sensing the presence of other users in a context. Frequent context profiling can also allow a mobile device to learn …

Divide And Recombine: Autoregressive Models And Stl+, Xiang Han

Open Access Dissertations

In this thesis multiple methods are proposed and applied to the Akamai CIDR time series data. The Akamai network is one of the world's largest distributed-computing platforms, with more than 250,000 servers in more than 80 countries. It is responsible for 15-20 percent of all web traffic. We obtained 110 GB raw CIDR data over a 18 month period, collected on the Akamai network from November 2011 to April 2013. ^ The Seasonal-Trend Decomposition procedure based on loess (STL+) is used to model the CIDR series. Motivated by the CIDR series analysis, we propose a general prediction based model selection …

Spatial Marked Point Processes: Models And Inferences, Yen-Ning E Huang

Open Access Dissertations

A spatial marked point process describes the locations of randomly distributed events in a region, with a mark attached to each observed point. Nowadays, the availability of spatiotemporal data is increasing and many spatiotemporal models are studied with applications in a wide range of disciplines. Spatial marked point processes are then extended to spatiotemporal marked point processes if time component is taken into account. In general, the marks can be quantitative or categorical variables. Independence between points and marks is a convenient assumption, but may not be true in practice. Tests for independence between points and marks are proposed previously, …

The Tessera D&R Computational Environment: Designed Experiments For R-Hadoop Performance And Bitcoin Analysis, Jianfu Li

Open Access Dissertations

D&R is a statistical framework for the analysis of large complex data that enables feasible and practical analysis of large complex data. The analyst selects a division method to divide the data into subsets, applies an analytic method of the analysis to each subset independently with no communication among subsets, selects a recombination method that is applied to the outputs across subsets to form a result of the analytic method for the entire data. The computational tasking of D&R is nearly embarrassingly parallel, so D&R can readily exploit distributed, parallel computational environments, such as our D&R computational environment, Tessera.^ In …

Usability Of Immersive Virtual Reality Input Devices, Christopher G. Mankey

Open Access Dissertations

This research conducts a usability analysis of human interface devices within an Immersive Virtual Reality Environment. The analysis is carried out for two different interface devices, a commercially available Intersense ^© Wand and a home built pinch glove and wireless receiver. Users were asked to carry out a series of minor tasks involving placement of shaped blocks into corresponding holes within an Immersive Virtual Reality Environment. Performance was evaluated in terms of speed, accuracy and precision via the collection of completion times, errors made and the precision of motion during the experiment.

Theory Of Density Functionals, Martin A. Mosquera-Tabares

Open Access Dissertations

Density functional theory is an alternative quantum mechanical theory that offers simple ways of performing calculations of the electronic properties of matter. Many different methods derive from density functional theory. The most appealing for its simplicity and rigor is the theory of Kohn and Sham. In this thesis I propose new methods in density-functional theory that are helpful to address some important problems in the application of the local-density approximation within Kohn-Sham DFT to the analysis of ground-states and dynamical properties of electronic systems.

Excited States Of Chromophores And Vibronic Interactions, Benjamin T. Nebgen

Open Access Dissertations

The main focus of my Ph.D. work has been on building a vibronic coupling model for multichromophores and extending that model to more general systems. This Dissertation serves as both a summary of this work as well as a manual for the two vibronic coupling programs I have written. It is my hope that the instructions written here are complete enough for any who would like to replicate my work on vibronic coupling on other systems. ^ Additionally, I have also worked on a few purely computational projects not directly related to the vibronic coupling work. The status of these …