Physical Sciences and Mathematics Commons^™

The Weakness Of Winrar Encrypted Archives To Compression Side-Channel Attacks, Kristine Arthur-Durett

Open Access Theses

Arthur-Durett, Kristine MS, Purdue University, December 2014. The weakness of WinRAR encrypted archives to compression side-channel attacks. Major Professor: Eugene Spaff This paper explores the security of WinRAR encrypted archives. Previous works concerning potential attacks against encrypted archives are studied and evaluated for practical implementation. These attacks include passive actions examining the effects of compression ratios of archives and the fi contained, the study of temporary ar- tifacts and active man-in-the-middle attacks on communication between individuals. An extensive overview of the WinRAR software and the functions implemented within it is presented to aid in understanding the intricacies of attacks against …

Dropwise Condensation Dynamics In Humid Air, Julian Eduardo Castillo Chaco

Open Access Theses

Dropwise condensation of atmospheric water vapor is important in multiple practical engineering applications. The roles of environmental factors and surface morphology/chemistry on the condensation dynamics need to be better understood to enable efficient water-harvesting, dehumidication, and other psychrometric processes. Systems and surfaces that promote faster condensation rates and self-shedding of condensate droplets could lead to improved mass transfer rates and higher water yields in harvesting applications. The thesis presents the design and construction of an experimental facility that allows visualization of the condensation process as a function of relative humidity. Dropwise condensation experiments are performed on a vertically oriented, hydrophobic …

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 …

The Barriers To Adopting Composting Toilets Into Use In Urban And Suburban Locations In The United States, Julia Branstrator

Open Access Theses

The amount of fresh water available in the world is a finite resource. Large quantities of the fresh water are located in remote locations, while more accessible sources of fresh water are disproportionately distributed around the world. Some populations lack reliable access to clean water for daily life, making the routine use of potable water in toilets of upper-income countries a questionable practice in terms of resource responsibility, energy use, and sustainable infrastructure. The innovative nature of composting toilets offers potential solutions to the downfalls of conventional, waterborne toilets. However, the path to adoption of composting toilets has encountered barriers …

Assessing Positional Accuracy And Correcting Point Data For Digital Soil Mapping At Varying Scales, Minerva J. Dorantes

Open Access Theses

Accuracy, timeliness, and the effect of scale of soil maps are rarely assessed. The recent increase in the use of GIS technologies and modelling software in natural resources and land management, has increased the demand for soil information at a finer resolution worldwide. Most of the world's developing countries rely on soils information at a scale that is too coarse for practical planning, and have obstacles impeding collection of new data, such as civil war and a lack of collection resources. The United States has an exhaustive collection of soils data at a fine scale. However, its location information is …

Vegetation And Soil Characteristics Of Pine Plantations And Naturally Regenerated Hardwood Forests On The Hoosier National Forest, Patrick James Duffy

Open Access Theses

During the 1930s there was widespread erosion on farmland and subsequent land abandonment. As a result, Pinus strobus L. (white pine), P. resinosa Aiton (red pine), and P. echinata Mill. (shortleaf pine) were planted in the Midwest to prevent erosion and rehabilitate sites. These species were selected due to their wide availability at the time. Currently, it is the goal of the U.S. Forest Service to provide a more natural and sustainable landscape, in part by removing these non-native Pinus stands and by replacing them with native hardwood species. The ultimate success of hardwood restoration depends, in part, on the …

High Voltage Rear Electric Drivetrain Design For A Parallelthrough-The-Road Plug-In Hybrid Electric Vehicle, Adam Garrett Fogarty

Open Access Theses

Purdue University was selected as one of 15 universities to participate in a three year Advanced Vehicle Technology Competition (AVTC) called EcoCar2: Plugging Into the Future. The vehicle built by the Purdue team was a Parallel-Through-The-Road Plug-in Hybrid Electric Vehicle (PTTR PHEV). The vehicle utilized a B20 diesel powertrain to power the front wheels, as well as a custom electric drivetrain to power the rear wheels. Using this vehicle during the final year of the competition, the team was successful in placing 4th overall as well as 2nd in the category of Well-To-Wheel (WTW) Greenhouse Gas Emissions. A stock 2013 …

Reverse-Phase Liquid Chromatography Of Small Molecules Using Silica Colloidal Crystals, Natalya Khanina

Open Access Theses

Capillaries packed with a silica colloidal crystal (SCC) of 470 nm nonporous particles have recently been shown to offer significant improvements in the peak width, resolution, and speed of protein analysis due to the reduction of the A and C term broadening contributions of the Van Deemter equation. While protein separations using this technology have shown vast improvements, small molecules remain largely unexplored. As the SCC allows for an approximately diffusion limited system, extremely high plate numbers are expected for small molecule separations. The research presented herein studies the feasibility of pressure-driven small molecule separation using SCCs and commercial instrumentation. …

Uncertainty, Irreversibility, And Investment In Secondgeneration Biofuels, Tanner Joseph Mccarty

Open Access Theses

The present study formalizes and quantifies the importance of uncertainty for investment in a corn-stover based cellulosic biofuel plant. Using a real options model we recover prices of gasoline that would trigger entry into the market and calculate the portion of that entry trigger price required to cover cost and the portion that corresponds to risk premium. We then discuss the effect of managerial flexibility on the entry risk premium and the prices of gasoline that would trigger mothballing, reactivation, and exit. Results show that the risk premium required by plants to enter the second-generation biofuel market is likely to …

Propogation Of Wind Turbine Noise Through Wakes And Turbulent Atmosphere, Yuan Peng

Open Access Theses

It is well known that the atmospheric inhomogeneities have great impact on sound propagation over long ranges. For the application of predicting wind turbine noise, either the flow wakes generated by rotating turbine blades or small-scale atmospheric turbulence can affect the propagation of sound over ground surfaces from individual turbines.

In this thesis, the effects of wake and atmospheric turbulence on the propagation of wind turbine noise are investigated. By introducing the Parabolic Equation (PE) method, the effects of atmospheric changes in sound speed can be incorporated at each marching step as the prediction of sound field advances in the …

Identifying Conditions To Optimize Lactic Acid Production From Food Waste, Raymond M. Redcorn

Open Access Theses

There is an increased demand for lactic acid for the production of biopolymers and to aid nutrient removal in wastewater treatment. Food waste offers a source of soluble sugars to produce lactic acid, which does not increase land demand, but digestion conditions have yet to be optimized when co-digested with primary sludge. Food waste was collected from cafeteria waste bins, homogenized and seeded with primary sludge. A Box Behnken Response surface design was used to optimize lactic acid production based on pH, temperature, loading rate, and retention time. Subsequent experiments verified and refined those conditions to optimize for both yield …

Indoor Acoustic Mapping And Geolocation, Thomas Shyy

Open Access Theses

The Global Positioning System (GPS) is widely used in navigations of flights, vehicles and travelers nowadays. However, the signals are not always available and there are some cases where the receptions of the GPS signal can be lost because of the presence of urban canyons, buildings, tunnels and forests. Another down side for the GPS is that indoor positioning can be really difficult because of the greater signal interference from the indoor.

On the other hand, the concept of echolocation has also been used for positioning purposes. Echolocation offers a promising approach to improve the quality of life of people …