Digital Commons Network^™

Analysis Of Outsourcing Data To The Cloud Using Autonomous Key Generation, Mortada Abdulwahed Aman

Masters Theses

"Cloud computing, a technology that enables users to store and manage their data at a low cost and high availability, has been emerging for the past few decades because of the many services it provides. One of the many services cloud computing provides to its users is data storage. The majority of the users of this service are still concerned to outsource their data due to the integrity and confidentiality issues, as well as performance and cost issues, that come along with it. These issues make it necessary to encrypt data prior to outsourcing it to the cloud. However, encrypting …

Preformed Particle Gel Conformance Control Performance In Partially Opened Fracture And Fully Opened Fracture Systems, Ghith Ali Ahmed Biheri

Masters Theses

"Conformance problems, such as reservoir heterogeneity can result in a significant decrease in oil recovery, and an excessive water production. Millimeter particle gels (PPG) have been used as conformance control agents to plug open fractures, however, very little research has been conducted to study their ability to plug partially open fractures. This research studies the ability of the PPG to plug partially open fracture to improve conformance and increase recovery in oil reservoirs. Rectangular Sandstone cores were used to conduct the experiments. Fracture widths used include 2, 3.5, 5 mm. For each fracture width, four gel strengths were used; gel …

Multiple Security Domain Model Of A Vehicle In An Automated Vehicle System, Uday Ganesh Kanteti

Masters Theses

"This thesis focuses on the security of automated vehicle platoons. Specifically, it examines the vulnerabilities that occur via disruptions of the information flows among the different types of sensors, the communications network and the control unit in each vehicle of a platoon. Multiple security domain nondeducibility is employed to determine whether the system can detect attacks. The information flows among the various domains provide insights into the vulnerabilities that exist in the system by showing if an attacker’s actions cannot be deduced. If nondeducibility is found to be true, then an attacker can create an undetectable attack. Defeating nondeducibility requires …

Well Log Interpretation And 3d Reservoir Property Modeling Of Maui-B Field, Taranaki Basin, New Zealand, Aziz Mennan

Masters Theses

"Maui-B is one of the largest hydrocarbon-producing fields in the Taranaki Basin. Many previous works have estimated reservoir volume. This study uses 3D property modeling, which is one of the most powerful tools to characterize lithology and reservoir fluids distribution through the field. This modeling will help in understanding the reservoir properties and enhancing the production by selecting the best location for future drilling candidates. In this study, 3D seismic, core, and well log data were used to build and define a structural model, facies analysis, and petrophysical parameters. After well log interpretation and petrophysical parameter calculations, each parameter was …

Communicating With Customers On Social Media In The United States And South Korea: An Analysis Of Four Companies' Practices, Yeonkyung Lee

Masters Theses

"In this study, I analyzed four companies' Facebook and Twitter posts to study the similarities and differences of American and Korean businesses' communication practices on social media. The study used a qualitative research method: each Facebook and Twitter post was assigned as a unit and coded. Southwest Airlines, General Electric, Asiana Airlines, and Samsung Electronics were selected, and a total of 402 Facebook posts and 465 Tweets from July 6 to September 5, 2016, were collected. Each post was coded by two coders under three coding categories: post-content, medium, and Aristotle's pisteis. After the data was coded, I analyzed each …

Diffusion And Mechanical Characterization Of Nanoparticle-Enabled Diffusion Controlled Materials, Joseph Louis Volpe

Masters Theses

"Nanoparticle-enabled diffusion control has been shown to rapidly refine multiphase microstructures during slowly cooled casting. This thesis characterizes the diffusion and the mechanical properties of nanoparticle-enabled diffusion controlled materials. To characterize diffusion properties, in situ characterization is performed to verify the nanoparticle enabled diffusion control mechanism. Materials with nanoparticles were observed to decrease the diffusion coefficient by at least one order of magnitude under similar melting conditions as compared to materials without nanoparticles. To understand mechanical properties, the nanoparticles that assembled at the growing interface were characterized under mechanical tensile stress. Nanoparticle-enabled interfaces were observed to improve the interface bond …

Comparing Region Level Testing Methods For Differential Dna Methylation Analysis, Arnold Albert Harder

Masters Theses

”Finding possible connections and solutions to help fight progression of diseases is a major area of research. Genomics is a primary path of research in disease research. Through the DNA sequence, possible connections to diseases have been found. However, most methods for fixing issues within a DNA sequence are still out of reach. One potential path is to investigate epigenetic modifications, such as DNA methylation. DNA methylation occurs when a methyl group attached to cytosines on the DNA sequence. Statistical methods can be used to identify sites or regions of significant differences in methylation levels between groups ( e. g. …

In-Situ Control Of Substrate Temperature In Additive Manufacturing To Homogenize Micro-Hardness Of Laser Clad Deposits Using Thermo-Electric Cooling, Raghu Ram Kolla

Masters Theses

”Nickel hard-surfacing alloys are replacing hard Chromium coatings due to their excellent wear and corrosion-resistant properties. In laser cladding of these alloys, however, these properties can vary across the height of the deposit due to an accumulation of excess heat generated in the deposit during the process. This may result in uneven wear of the clad parts which can be detrimental for practical purposes. The research objective is to develop an in-situ cooling system that works in line with the laser deposition system to extract the excess heat buildup and reduce the variation in the hardness of the Ni-based clad …

Automatic Discrimination Of Basal Cell Carcinoma From Sebaceous Hyperplasia Based On Image Processing Of Dermoscopy Images, Jonathan Liao

Masters Theses

“This project focuses on discriminating basal cell carcinoma from sebaceous hyperplasia using image processing techniques. Basal cell carcinoma is a kind of malignant skin cancer that needs to be treated; however, if diagnosed as sebaceous hyperplasia, a benign lesion which is a mimic of basal cell carcinoma, then it may not be treated properly. Through observation, white pouch-like areas within the lesion appear in sebaceous hyperplasia images; whereas in basal cell carcinoma images, white areas tend to be formed in a smashed irregular figure shape. Hence, utilizing image processing techniques to segment these white areas from the images and using …

A Study Of The Potential Applications Of Am241, And Determining The Feasibility Of Using Gamma Spectroscopy For Future Physical Validation, Eric A. Feissle

Masters Theses

“Am241 is typically produced via Pu241 decay in a uranium fueled reactor. Presence of Am241 can be used as the age estimation tool for spent fuel, which is a focus of this thesis along with the interest of the measurement and the ratio of production rates of Am241’s activation products; Americium-242 and its first excited state of Americium-242m. MCNP models of the core and BEGe 3825 detector were built. These models were compared with established and physical measurements of gamma/x-ray standards that were available at the reactor. Thermal fluxes at 200 kW for potential foils centered in the source holder …

An Investigation Of Borax For Sealing Inflow From Berea Sandstone, Tri-Tris Bao Nguyen

Masters Theses

"Well inflow control is a major challenge for the oil and gas industry. Erle Haliburton revolutionized well inflow control with his patent for cementing oil wells in 1921. Soon after, cement became the accepted material to establish well integrity and has been ever since. Cement is used in all phases of the well life cycle, and it is expected to hold indefinitely once set. Yet based on the nature of cement and the placement techniques, flow pathways may develop from improper cementing jobs or from cement degradation over time. Well integrity is especially crucial for wellbore plugging and abandonment, since …

Plume Characterization Of Electric Solid Propellant Pulsed Microthrusters, Matthew S. Glascock, Joshua L. Rovey, Shae Williams, Jason Thrasher

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Electric solid propellants are an attractive option for propulsion because they are ignited only by an applied electric current. This leads to capabilities such as on-demand throttling and reignition in chemical combustion operation, and it lends itself to application in electric propulsion. In this work, the plasma plume created by electric solid propellant pulsed micro thrusters is investigated using a nude Faraday probe, a triple Langmuir probe, and residual gas analysis. The thrusters are tested at a vacuum level of 2 x 10-5torr. Results indicate an average plume electron temperature of 1.7 eV and a density of 1011 to 1014cm-3. …

Nanoparticle-Induced Unusual Melting And Solidification Behaviours Of Metals, C. Ma, Lianyi Chen, C. Cao, X.C. Li

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Textured Nise₂ Film: Bifunctional Electrocatalyst For Full Water Splitting At Remarkably Low Overpotential With High Energy Efficiency, Abdurazag T. Swesi, Jahangir Masud, Wipula P. R. Liyanage, Siddesh Umapathi, Eric W. Bohannan, Julia E. Medvedeva, Manashi Nath

Physics Faculty Research & Creative Works

Herein we have shown that electrodeposited NiSe₂ can be used as a bifunctional electrocatalyst under alkaline conditions to split water at very low potential by catalyzing both oxygen evolution and hydrogen evolution reactions at anode and cathode, respectively, achieving a very high electrolysis energy efficiency exceeding 80% at considerably high current densities (100 mA cm^-2). The OER catalytic activity as well as electrolysis energy efficiency surpasses any previously reported OER electrocatalyst in alkaline medium and energy efficiency of an electrolyzer using state-of-the-art Pt and RuO₂ as the HER and OER catalyst, respectively. Through detailed electrochemical and …

Control Of Columnar To Equiaxed Transition In Solidification Macrostructure Of Austenitic Stainless Steel Castings, Semen Naumovich Lekakh, Ronald J. O'Malley, Mark C. Emmendorfer, Brenton Hrebec

Materials Science and Engineering Faculty Research & Creative Works

Solidification macrostructure is of great importance for the properties and the quality of castings made from austenitic grade stainless steels (ASS) because there are limited options to change as-cast macrostructure in the solid condition. A typical cast macrostructure of ASS has a fine surface chilled zone followed by an elongated dendrite zone, columnar to equiaxed transition (CET) zone, and centrally located equiaxed crystals. Several castings from ASS were produced to determine the effects of casting geometry, chilling, and grain refinement on CET. The transient thermal field in solidified heavy castings was simulated and used to determine an isotherm velocity (V) …

Resilient Control Of Active-Passive Networked Multiagent Systems In The Presence Of Persistent Disturbances, Dzung Tran, Tansel Yucelen, John Daniel Peterson

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An active-passive networked multiagent system consists of agents subject to inputs (active agents) and agents without any inputs (passive agents). Specifically, this class of networked multiagent systems utilizes a novel form of dynamic consensus filters, where the states of all agents converge to the average of the exogenous inputs applied only to the active agents, and it has broad practical applications including, for example, real-time situational awareness and data gathering using sensor networks and distributed control of multirobot systems. In this paper, we focus on active-passive networked multiagent systems that are subject to constant and/or harmonic exogenous disturbances. In particular, …

Assessment Of Multimode Spacecraft Micropropulsion Systems, Steven P. Berg, Joshua L. Rovey

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Multimode spacecraft micro propulsion systems that include a high-Thrust chemical mode and high-specific impulse electric mode are assessed with specific reference to CubeSat-sized satellite applications. Both cold-gas butane propellant and ionic liquid chemical monopropellant modes are investigated alongside pulsed plasma, electrospray, and ion electric thruster modes. These systems are studied by varying electric propulsion usage percent and calculating the payload mass fraction and thruster burn time for missions requiring 250, 500, and 1000 m/s delta-V. Systems involving chemical monopropellants have the highest payload mass fractions for a reference mission of 500 m/s delta-V and 6U-sized CubeSat, where 1U is a …

A Collimated Surface-Wave-Excited High-Impedance Surface Leaky-Wave Antenna, Zi Long Ma, Chi Hou Chan, Kung Bo Ng, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

This letter presents a novel high-impedance surface (HIS)-based leaky-wave antenna excited by collimated surface wave (SW). The proposed antenna consists of two identical SW launchers (SWLs) and an HIS structure. Regarding the SWL, it is based on an offset-fed parabolic reflector. By using the substrate-integrated waveguide technique, the reflector system is integrated in the planar substrate. For the HIS, it is formed by a periodically arranged rectangular microstrip patch array. The proposed SWL can generate collimated SW with the propagation mode. With the perturbation of the HIS, the guided SW can be transformed to m = -1 space-harmonic-mode leaky wave. …

The Rollamo 2017, Missouri University Of Science And Technology

Yearbooks

No abstract provided.

Decision Process In Mcdm With Large Number Of Criteria And Heterogeneous Risk Preferences, Jian Liu, Hong Kuan Zhao, Zhao Bin Li, Si Feng Liu

Electrical and Computer Engineering Faculty Research & Creative Works

A new decision process is proposed to address the challenge that a large number of criteria in the multi-criteria decision making (MCDM) problem and the decision makers with heterogeneous risk preferences. First, from the perspective of objective data, the effective criteria are extracted based on the similarity relations between criterion values and the criteria are weighted, respectively. Second, the corresponding types of theoretic model of risk preferences expectations will be built, based on the possibility and similarity between criterion values to solve the problem for different interval numbers with the same expectation. Then, the risk preferences (Risk-seeking, risk-neutral and risk-aversion) …

An Efficient Numerical Contour Deformation Method For Calculating Electromagnetic Scattered Fields From 3-D Convex Scatterers, Yu Mao Wu, Weng Cho Chew, Ya Qiu Jin, Tie Jun Cui, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

We consider the accuracy improvement of the high frequency scattered fields from 3-D convex scatterers. The Fock currents from the convex scatterers are carefully studied. Furthermore, we propose the numerical contour deformation method to calculate the Fock currents with frequency independent workload and error controllable accuracy. Then, by adopting the Fock currents and the incremental length diffraction coefficient (ILDC) technique, the scattered fields are clearly formulated. Compared to physical optics (PO) scattered fields from 3-D convex sphere, numerical results demonstrate significant accuracy enhancement of the scattered field via the Fock current approach.

Robust Airfoil Design Optimization Using Stochastic Expansions And Utility Theory, Xiaosong Du, Leifur Leifsson, Slawomir Koziel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Efficient and effective robust airfoil design optimization is proposed by integrating stochastic expansions and utility theory. In this work, the stochastic expansions are generated efficiently using non-intrusive polynomial chaos (NIPC) expansions. The robust design problem is formulated using utility functions which transfer a targeted response using a prescribed mathematical function to represent the designers' risk preferences. The proposed approach is demonstrated using examples of lift-constrained airfoil drag minimization in transonic viscous flow using the Mach number as an uncertain variable in the range of 0.70 to 0.75. The results are compared with the common problem formulation for robust design of …

Causal Knowledge Promotes Behavioral Self-Regulation: An Example Using Climate Change Dynamics, David K. Sewell, Peter J. Rayner, Daniel Burton Shank, Sophie Guy, Simon D. Lilburn, Saam Saber, Yoshihisa Kashima

Psychological Science Faculty Research & Creative Works

Adopting successful climate change mitigation policies requires the public to choose how to balance the sometimes competing goals of managing CO₂ emissions and achieving economic growth. It follows that collective action on climate change depends on members of the public to be knowledgeable of the causes and economic ramifications of climate change. The existing literature, however, shows that people often struggle to correctly reason about the fundamental accumulation dynamics that drive climate change. Previous research has focused on using analogy to improve people's reasoning about accumulation, which has been met with some success. However, these existing studies have neglected …

Development And Implementation Of Star Tracker Based Attitude Determination, Casey Grant Smith

Masters Theses

"As interest in nanosatellites grows within the university community, the demand for inexpensive, space-grade hardware grows as well. Star trackers can be a luxury item for some spacecraft and therefore are often not considered due to their cost. Ideally, a star tracker could be built using inexpensive parts so long as the software is available. Unlike many other attitude determination instruments, star trackers are renowned for their high accuracy, yielding accurate and precise attitude estimates. However, development of this software can be overwhelming for the university settling, especially when multiple missions are on hand. If these instruments were readily available …

Novel Approaches For Efficient Stochastic Computing, Ramu Seva

Masters Theses

"This thesis is comprised of two papers, where the first paper presents a novel approach for parallel implementation of SC using FPGA (Field Programmable Gate Array). This paper makes use of the distributed memory elements of FPGAs (i.e., look-up-tables -LUTs) to achieve this. An attempt has been made to build the stochastic number generators (SNGs) by using the proposed LUT approach. The construction of these SNGs has been influenced by the Quasi-random number sequences, which provide the advantage of reducing the random fluctuations present in the pseudo-random number generators such as LFSR (Linear Feedback Shift Register) as well as the …

A Comprehensive Analysis Of Lost Circulation Materials And Treatments With Applications In Basra's Oil Fields, Iraq: Guidelines And Recommendations, Husam Hasan Alkinani

Masters Theses

"Lost circulation materials (LCM's) have been widely used to avoid or stop losses. Due to a large number of current available LCM's and their different applications, classification of LCM's is very important. The most recent LCM classification was published around 50 years ago, and this paper intends to fill this gap with an updated classification including conventional and new technologies. Lost circulation materials and treatments are re-classified into various categories based on their appearance, applications, chemical and physical properties.

Wells in Basra's oil fields are highly susceptible to lost circulation problems when drilling through the Dammam, Hartha, and Shuaiba formations. …

Predicting The Impact Of Data Corruption On The Operation Of Cyber-Physical Systems, Erik David Burgdorf

Masters Theses

"Cyber-physical systems, where computing and communication are used to fortify and streamline the operation of a physical infrastructure, now comprise the foundation of much of modern critical infrastructure. These systems are typically large in scale and highly interconnected, and span application domains from power and water distribution to autonomous vehicle control and collaborative robotics. Intelligent decision support in these systems is heavily reliant on the availability of sufficient and sufficiently correct data. Failure or malfunction of these systems can have devastating consequences in terms of public safety, financial losses, or both.

The research described in this thesis aims to predict …

Liquid Pulsed Plasma Thruster Plasma Plume Investigation And Mr-Sat Cold Gas Propulsion System Performance Analysis, Jeremiah Daniel Hanna

Masters Theses

"The plasma plume produced by a liquid pulsed plasma thruster is investigated using a Langmuir triple probe and a nude Faraday probe. The Langmuir triple probe failed to produce results which are suspected caused by the presence of ionic liquid in the plume resulting in shorting of the probe. The nude Faraday probe is able to record the ion current density which revealed a high level of inconsistency in the plasma plume. Ion current density recorded by the nude Faraday probe had a relative standard deviation of upwards of 100% of the mean value. Controlling the amount of propellant used …

Classification Of Basal Cell Carcinoma Using Telangiectatic Vessels And Machine Learning, Hemanth Yadav Aradhyula

Masters Theses

“Basal cell carcinoma (BCC) is one of the most common types of skin cancer in the United States. Early detection of BCC by noninvasive techniques can decrease delay in treatment and save cost. A recent study estimated that 5.4 million cases of non-melanocytic skin cancer (NMSC) occur each year in the US. BCC accounts for 50% of NMSC cases. Telangiectasia, which appears in most BCCs is an important feature for identification of BCC for an automatic diagnostic system. In this thesis, three methods for detection of telangiectasia present in dermoscopy lesion image (DI) were proposed. Detected telangiectasia in DI was …

Error Mapping Of Build Volume In Selective Laser Melting, Ninad Kulkarni

Masters Theses

“Selective laser melting is one of the commonly used additive manufacturing processes employed for production of functional part. Therefore, quality aspects such as dimensional accuracy have become a point of great interest. Like all of the other additive manufacturing processes selective laser melting process suffers from the issue if having wide range of process parameters making the process control a complex task. Additionally, issues specific to the selective laser melting process such as position dependency of accuracy of the part, makes it difficult to predict the resulting dimensional inconsistencies in the part manufactured by this processes. This research is an …