Digital Commons Network^™

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 …

Multiple Security Domain Nondeducibility Air Traffic Surveillance Systems, Anusha Thudimilla

Masters Theses

"Traditional security models partition the security universe into two distinct and completely separate worlds: high and low level. However, this partition is absolute and complete. The partition of security domains into high and low is too simplistic for more complex cyber-physical systems (CPS). Absolute divisions are conceptually clean, but they do not reflect the real world. Security partitions often overlap, frequently provide for the high level to have complete access to the low level, and are more complex than an impervious wall. The traditional models that handle situations where the security domains are complex or the threat space is ill …

Overview Of Co₂ Leakage Problems And Sealants For Co₂ Leakage Remediation, Shudai Peng

Masters Theses

"Excessive Carbon Dioxide (CO₂) emission has become a serious issue and caused lots of environmental problems. Carbon Capture and Storage (CCS) program has been developed to reduce the CO₂ content in the atmosphere. CO₂ storage has been targeted mainly on depleted oil or gas reservoirs and deep saline aquifers. However, leakage could occur through wellbores, cap rocks, formation faults, and fractures during and after CO₂ injection. To minimize the risk, different types of sealants have been investigated to prevent CO₂ leaks. The aim of this thesis is to provide a comprehensive review of the materials which could be used as …

Contributing Factors To Child Stunting In Guatemala: A Systems Analysis Focused On Enteric Disease Transmission And Mycotoxin Exposure, Lee Emerson Voth-Gaeddert

Doctoral Dissertations

"Child stunting -- low height-for-age -- is a United Nation's indicator for chronic malnutrition that has been linked to both acute and chronic health problems. Data from Guatemala suggests for children under five years of age, 49% are classified as stunted. This dissertation tests the following hypotheses, among children in Guatemala 1) environmental enteric dysfunction (EED) is correlated with height-for-age, 2) aflatoxin B (AFB) exposure is correlated with height-for-age, and 3) AFB exposure is correlated with EED. A network analysis was conducted on data from the US Agency for International Development (USAID) collected in 2012 to identify trends in a …

A Functional Data Analytic Approach For Region Level Differential Dna Methylation Detection, Mohamed Salem F. Milad

Doctoral Dissertations

"DNA methylation is an epigenetic modification that can alter gene expression without a DNA sequence change. The role of DNA methylation in biological processes and human health is important to understand, with many studies identifying associations between specific methylation patterns and diseases such as cancer. In mammals, DNA methylation almost always occurs when a methyl group attaches to a cytosine followed by a guanine (i.e. CpG dinucleotides) on the DNA sequence. Many statistical methods have been developed to test for a difference in DNA methylation levels between groups (e.g. healthy vs disease) at individual cytosines. Site level testing is often …

Privacy Setting Recommendation For Image Sharing, Jun Yu, Zhenzhong Kuang, Zhou Yu, Dan Lin, Jianping Fan

Computer Science Faculty Research & Creative Works

This paper aims to simultaneously consider two inseparable issues for privacy setting recommendation: (1) sensitiveness of visual content of the images being shared; and (2) trustworthiness of users being granted. First, an object-based approach is developed for image content sensitiveness (privacy) representation. Secondly, the users on a social network are clustered into a set of representative social groups to generate a discriminative dictionary for user trustworthiness characterization. Finally, a tree classifier is trained hierarchically to recommend appropriate privacy settings for image sharing.

Ior Methods In Unconventional Reservoirs Of North America: Comprehensive Review, Dheiaa Alfarge, Mingzhen Wei, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Unconventional resources have played a significant role in changing oil industry plans recently. Shale formations in North America have huge oil in place, 900 billion barrels of recoverable oil in Bakken only. However, the predicted primary recovery is still low as less than 10%. Therefore, seeking for improved oil techniques to increase oil recovery in these complex plays is inevitable. In this paper, three stages of review have been combined to find out the applicability of the most feasible IOR methods in these unconventional reservoirs. Firstly, the most common fluid and rock properties of these reservoirs have been investigated and …

Selection Criteria For Miscible-Gases To Enhance Oil Recovery In Unconventional Reservoirs Of North America, Dheiaa Alfarge, Mingzhen Wei, Baojun Bai, Mortadha Alsaba

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Unconventional resources have played a significant role in changing oil industry plans recently. Shale formations in North America such as Bakken, Niobrara, and Eagle Ford have huge oil in place, 100-900 billion barrels of oil in Bakken only. However, the predicted primary recovery is still low as 5-10%. Therefore, seeking for techniques to enhance oil recovery in these complex plays is inevitable. In this paper, two different approaches have been integrated to investigate the feasibility of three different miscible gases which are CO₂, lean gases, and rich gases. Firstly, numerical simulation methods of compositional models have been incorporated …

Wellbore Stability Evaluation For Mishrif Formation, Ethar H.K. Alkamil, Husam R. Abbood, Ralph E. Flori, Andreas Eckert

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

During drilling operations for the E oilfield in the Mishrif formation in southern Iraq, stuck pipe has been identified as a significant geomechanical problem for several wells. In this study, a 1-D mechanical earth model (MEM) of the Mishrif formation is compiled based on its state of stress and rock strength parameters and is utilized to assess the contribution of borehole collapse leading to the stuck pipe problems. The MEM model is based on the principal in situ stresses and their orientation obtained from wireline logs measurements, measuring while drilling (MWD), and leak off test (LOT). Rock strength properties are …

Integrating Microgels And Low Salinity Waterflooding To Improve Conformance Control In Fractured Reservoirs, Ali Alhuraishawy, Mingzhen Wei, Baojun Bai, Abdullah Almansour

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The recovery from fractured reservoirs is usually low. The areal heterogeneity is one result of the fractured reservoir. Low salinity waterflooding (LSWF) and preformed particle gel (PPG) have recently investigated by some researchers. The main objective of this study was to determine whether the combining technologies can improve conformance control in fractured sandstone reservoirs. Semi-transparent five-spot models made of sandstone cores and acrylic plates were built. The effect of low salinity waterflooding on oil recovery was studied. Models were designed with three parallel open fractures. Sodium chloride (1.0, 0.1, 0.01, and 0.001 wt. % NaCl) were used for brine flooding …

Effect Of Molecular-Diffusion Mechanisim On Co2 Huff-N-Puff Process In Shale-Oil Reservoirs, Dheiaa Alfarge, Mingzhen Wei, Baojun Bai, Abdullah Almansour

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Unconventional resources have played a significant role in changing oil industry plans recently. Shale formations in North America such as Bakken, Niobrara, and Eagle Ford have huge oil in place, 100-900 billion barrels of recoverable oil in Bakken only. However, the predicted primary recovery is still low as less than 10%. Therefore, seeking for techniques to increase oil recovery in these complex plays is inevitable. In this paper, three different approaches have been combined to investigate the effect of molecular-diffusion mechanism on CO₂ huff-n-puff process in Bakken formation. Firstly, comprehensive review has been conducted on the reported experimental studies …

Novel Environmentally Benign Hydrogel: Nano-Silica Hybrid Hydrolyzed Polyacrylamide/ Polyethyleneimine Gel System For Conformance Improvement In High Temperature High Salinity Reservoir, Liping Ma, Shitou Wang, Yifu Long, Changqian Zhu, Hongbin Yang, Tangying Yang, Xiaochun Liu, Xiaorong Li, Baojun Bai, Wanli Kang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In order to address the conformance problem in high temperature and high salinity/hardness reservoir, an environmentally benign in-situ gel was developed based on hydrolyzed polyacrylamide (HPAM) and polyethyleneimine (PEI). Moreover, silica nanoparticle (SNP) was embedded to improve the performance of HPAM/PEI gel. To achieve the optimum formulation of HPAM/PEI-SNP gel, a comprehensive investigation was first conducted with the respect of gelation time, gel strength, and thermal stability. In addition, the particle size of SNP was determined by Dynamic Light Scatter (DLS) and the microstructure of HPAM/ PEI-SNP gel was characterized via Scanning Electron Microscopy (SEM). The optimum formulation, containing the …

Control Of Single- And Dual-Probe Atomic Force Microscopy, Muthukumaran Loganathan

Doctoral Dissertations

“Atomic force microscope (AFM) is one of the important and versatile tools available in the field of nanotechnology. It is a type of probe-based microscopy wherein an atomically sharp tip, mounted on the free end of a microcantilever, probes the surface of interest to generate 3D topographical images with nanoscale resolution. An integral part of the AFM is the feedback controller that regulates the probe deflection in the presence of surface height changes, enabling the control action to be used for generating topographical image of the sample. Besides sensing, the probe can also be used as a mechanical actuator to …

Survivability Modeling For Cyber-Physical Systems Subject To Data Corruption, Mark James Woodard

Doctoral Dissertations

"Cyber-physical critical infrastructures are created when traditional physical infrastructure is supplemented with advanced monitoring, control, computing, and communication capability. More intelligent decision support and improved efficacy, dependability, and security are expected. Quantitative models and evaluation methods are required for determining the extent to which a cyber-physical infrastructure improves on its physical predecessors. It is essential that these models reflect both cyber and physical aspects of operation and failure. In this dissertation, we propose quantitative models for dependability attributes, in particular, survivability, of cyber-physical systems. Any malfunction or security breach, whether cyber or physical, that causes the system operation to depart …

A Bounded Actor-Critic Algorithm For Reinforcement Learning, Ryan Jacob Lawhead

Masters Theses

"This thesis presents a new actor-critic algorithm from the domain of reinforcement learning to solve Markov and semi-Markov decision processes (or problems) in the field of airline revenue management (ARM). The ARM problem is one of control optimization in which a decision-maker must accept or reject a customer based on a requested fare. This thesis focuses on the so-called single-leg version of the ARM problem, which can be cast as a semi-Markov decision process (SMDP). Large-scale Markov decision processes (MDPs) and SMDPs suffer from the curses of dimensionality and modeling, making it difficult to create the transition probability matrices (TPMs) …

St. Louis Area Earthquake Hazards Mapping Project: Seismic And Liquefaction Hazard Maps, Chris H. Cramer, Robert A. Bauer, Jaewon Chung, J. David Rogers, Larry Pierce, Vicki Voigt, Brad Mitchell, David Gaunt, Robert A. Williams, David J. Hoffman, Gregory L. Hempen, Phyllis J. Steckel, Oliver Salz Boyd, Connor M. Watkins, Kathleen B. Tucker, Natasha S. Mccallister

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

We present probabilistic and deterministic seismic and liquefaction hazard maps for the densely populated St. Louis metropolitan area that account for the expected effects of surficial geology on earthquake ground shaking. Hazard calculations were based on a map grid of 0.005°, or about every 500 m, and are thus higher in resolution than any earlier studies. To estimate ground motions at the surface of the model (e.g., site amplification), we used a new detailed near-surface shear-wave velocity model in a 1D equivalent- linear response analysis. When compared with the 2014 U.S. Geological Survey (USGS) National Seismic Hazard Model, which uses …

Analysis Of Ior Pilots In Bakken Formation By Using Numerical Simulation, Dheiaa Alfarge, Mingzhen Wei, Baojun Bai, Mortadha Alsaba

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Bakken is the most productive formation among unconventional plays in North America. This formation has 7.4 billion barrels of recoverable oil. However, the primary oil recovery is still low as 5-10%. Miscible natural gas and carbon dioxide (CO₂) might be the most two potential strategies to improve oil recovery in such complex play. In this study, some of the IOR pilots which have been conducted in Montana, North Dakota, and South Saskatchewan have been presented. The performance results of these pilots in US-Bakken versus Canadian-Bakken have been compared. Moreover, the reasons beyond the successful IOR pilots in Canadian-Bakken …

Optimizing Injector-Producer Spacing For Co2 Injection In Unconventional Reservoirs Of North America, Dheiaa Alfarge, Mingzhen Wei, Baojun Bai, Abdullah Almansour

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Shale oil reservoirs such as Bakken, Niobrara, and Eagle Ford have become the main target for oil and gas investors as conventional formations started to deplete and diminish in number. These reservoirs have a huge oil potential; however, the predicted primary oil recovery is still low as average of 7.5 %. Carbon dioxide (CO₂) flooding has been a controversial approach to increase oil recovery in these poor-quality formations. This study investigated the effect of injector-producer spacing, in range of 925-1664 ft, on CO₂ performance in these plays by using numerical simulation methods. CO₂ utilization value under …

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 …

Wrinkling Of Functionally Graded Sandwich Structures Subject To Biaxial And In-Plane Shear Loads, Harold Costa

Masters Theses

"Benefits of a functionally graded core increasing wrinkling stability of sandwich panels have been demonstrated in a recent paper [1] where a several-fold increase in the wrinkling stress was observed, without a significant weight penalty, using a stiffer core adjacent to the facings. In the present paper wrinkling is analyzed in case where the facings are subject to biaxial compression and/or in-plane shear loading and the core is arbitrary graded through-the-thickness. Two issues addressed are the effect of biaxial or in-plane shear loads on wrinkling stability of panels with both graded and ungraded core and the verification that functional grading …

Evaluation Of Preformed Particle Gels Penetration And Propagation Behavior For A Conformance Control Treatment In Partially Open Conduits, Ahmed Mohamed Aldalfag

Masters Theses

"Preformed particle gels (PPGs) serve as a conformance control agent and have been used widely to control excess water production through conduits, fractures or fracture-like features. This research ranks the parameters that impact PPG resistance to water flow in partially opened conduits. Experiments were conducted to examine the effect of brine concentration, PPG injection pressure, back pressure, reducing water salinity and matrix permeability on PPG resistance to water flow through conduits, PPG penetration to the matrix. PPGs were swelled in different concentration brines and were injected into the conduits at a few designed injection pressures. PPG swollen in high brine …

Design And Analysis Of A Passive Heat Removal System For A Small Modular Reactor Using Star Ccm+, Raymond Michael Fanning

Masters Theses

"Next generation nuclear power plants, specifically small modular reactor designs, are the best alternative to fossil fuels for power generation due to their power density and low carbon emissions and constant awareness of safety concerns. A promising safety feature of new designs is the removal of heat by passive systems in accident scenarios. The passive systems require no moving parts and no intervention by personnel. These systems must be accurately simulated for better understanding of the heat transport phenomena: natural convection cooling. Due to the fact that most work developing these passive heat removal systems are proprietary information, a passive …

Bio-Inspired Flow Fields For Pem Fuel Cells- Decoupling Pressure And Distribution Effects On Performance And Identifying Design Opportunities, Joshua David Heck

Masters Theses

"The performance of Polymer Electrolyte Membrane Fuel Cells (PEMFCs) is significantly impacted by flow distributor geometry. The effects of flow distributor geometry on PEMFCs was explored in two ways in this study. Firstly, the relative effects of pressure and distribution characteristics of different flow fields on fuel cell unit and system level performance were considered. A method of decoupling these effects was proposed and demonstrated by application to the traditional serpentine and parallel flow field designs.The performance of these two designs were modeled computationally and it was shown that, of the 17% better performance of the serpentine design, 12% was …

Leveraging Knowledge At Startups, Amruta Anil Ranade

Masters Theses

"Startups contribute to the economy and job creation in the United States. One of the primary assets of startups is tacit knowledge of the employees of the startup. Technical communicators can help startups capture, share, and leverage the tacit knowledge at startups. Technical communicators could benefit from learning how knowledge management initiatives at startups work. The current study is an ethnographic case-study that was conducted at a fast-growing startup in California.

The data for the study was collected through observations, informal and semi-structured formal interviews with participants, and feedback from customers of the startup. The collected data was analyzed based …

Decodable Network Coding In Wireless Network, Junwei Su

Masters Theses

"Network coding is a network layer technique to improve transmission efficiency. Coding packets is especially beneficial in a wireless environment where the demand for radio spectrum is high. However, to fully realize the benefits of network coding two challenging issues that must be addressed are: (1) Guaranteeing separation of coded packets at the destination, and (2) Mitigating the extra coding/decoding delay. If the destination has all the needed packets to decode a coded packet, then separation failure can be averted. If the scheduling algorithm considers the arrival time of coding pairs, then the extra delay can be mitigated. In this …

Characterization Of The Rectification Behaviour Of In-Amps And Estimating The Near Field Coupling From Smps Circuits To A Nearby Antenna Using Dipole Moments, Chunyu Wu

Masters Theses

"This thesis discusses two parts.

In the first part, the rectification behavior of popular instrumentation amplifiers is measured in both common mode and single-ended RF noise injection. It is recommended that AD8221 be used in common mode RF noise injection environment. And AD8220 and AD8429 are recommended in single-ended RF noise injection environment. The mechanism of RF noise rectification inside in-amps is also discussed. It is verified that rectification mainly happens at the non-inverting input of two op-amps in the first stage of an in-amp. The DC voltage difference between inverting input and non-inverting input of the in-amp is further …

Effect Of Fracture Heterogeneity On Proppant Transport And Settling Mechanism, Dhurgham Abdulameer Kadhim

Masters Theses

"Proppant transport modeling through fractures with slickwater fluid systems assumes uniform and homogeneous fracture widths by implying constant fluid behavior at wall boundaries. Hydraulic fracturing mineback operations have demonstrated that induced fractures are heterogeneous and varying in width. This work investigates the impact of fracture width heterogeneity, roughness, and leak-off on ceramic proppant transport and settling, using proppant distribution concepts of Equilibrium Dune Level (EDL) and equilibrium Dune Length (EDX). Experimental work was conducted to investigate the impact of fracture width heterogeneity by varying fracture width along two plexiglass sheets. To mimic actual hydraulic fractures, the injection side was designed …

Facebook And Value Congruence, Andrew James Eyberg

Masters Theses

"The current discussion on the use of social networking sites (SNS) in personnel selection is mixed at best. The present research utilized participant's Facebook profiles to determine if raters can correctly - and accurately evaluate work value dimensions as a measure of person-organization fit. Similar research was successful in capturing personality dimensions via SNS (Buffardi & Campbell, 2009). Additionally, the value dimensions of the current measure used -- the Organizational Culture Profile (OCP) (O'Reilly et al., 1991) has been correlated with aspects of personality. Rater participants (N=105). Every five raters were randomly assigned five profiles to rate, for a total …

Detection Of Mine Roof Failure Using Inexpensive Lidar Technology, Ali Abdullah M. Alzahrani

Masters Theses

"Slope, Roof, and mine wall stability problems are some of the main reasons for deaths at U.S. surface or underground mining. The safety instruments were not enough to prevent that failure or even predict it before it occurs. However, the cost of such a tool that can be helpful in detecting roof failures is very high and not reachable in most instances.

The present study investigates the feasibility of using the M16 Leddar Evaluation Kit to detect the roof failure in mines. The M16 Leddar Evaluation kit cost is between 300$-800$, so it is the reachable price if it provides …

Quantifying Ceramic Proppant Transport In Complex Fracture Networks, Vivekvardhan Reddy Kesireddy

Masters Theses

"Water fracs have become an essential part of unconventional reservoirs to create deeper fracture networks. Proppant transport in water fracs is challenging in terms of fluids ability to carry the proppant deeper into these fracture networks. This experimental study investigates the impact of the flow rates, fracture widths and complexity controlling the ability of proppant to flow into complex fracture networks. This research attempts to nullify the knowledge gap in understanding width heterogeneity in primary and secondary fractures. This study speaks for settling pattern and proppant transport through a slot flow model with a unique approach to understand stage wise …