Engineering Commons^™

Higher-Order Effects In Biaxial Flexure Of Gfrp I-Section Beams, Zia Razzaq, Faridoon Z. Razzaq

Civil & Environmental Engineering Faculty Publications

A theoretical study of Glass Fiber Reinforced Polymer (GFRP) beams subjected to biaxial bending moments is presented with a focus on the influence of higher-order effects on maximum normal stresses. It is shown that the biaxial bending type of loading causes a dramatic increase in the maximum normal stress for a GFRP beam when induced torsional effects are included. The study demonstrates that the traditional first-order theory can grossly underestimate the maximum normal stress in a GFRP beam. Based on the numerical results presented using a higher-order theory which also accounts for induced warping normal stresses, the maximum normal stress …

Learning Curve Characterization Within Complex Low-Rate Production Environments, Robert J. Gies

Engineering Management & Systems Engineering Theses & Dissertations

Traditional and current learning curve approaches, methods, and theories were deficient when addressing complex low-rate production systems. The purpose of this research was to address this problem and develop a learning curve approach that characterizes learning in low-rate production environments such as naval ship construction. This research identified the principal aspects that influence learning within this environment and developed a learning characterization more reflective of this environment.

There obviously exists a large body of knowledge covering learning. However, the research contained herein addresses learning as it relates to learning curves in low-rate production environments, such as naval shipbuilding. The various …

Hard-Real-Time Computing Performance In A Cloud Environment, Alvin Cornelius Murphy

Engineering Management & Systems Engineering Theses & Dissertations

The United States Department of Defense (DoD) is rapidly working with DoD Services to move from multi-year (e.g., 7-10) traditional acquisition programs to a commercial industrybased approach for software development. While commercial technologies and approaches provide an opportunity for rapid fielding of mission capabilities to pace threats, the suitability of commercial technologies to meet hard-real-time requirements within a surface combat system is unclear. This research establishes technical data to validate the effectiveness and suitability of current commercial technologies to meet the hard-real-time demands of a DoD combat management system. (Moreland Jr., 2013) conducted similar research; however, microservices, containers, and container …

Cyber Resilience Analytics For Cyber-Physical Systems, Md Ariful Haque

Electrical & Computer Engineering Theses & Dissertations

Cyber-physical systems (CPSs) are complex systems that evolve from the integrations of components dealing with physical processes and real-time computations, along with networking. CPSs often incorporate approaches merging from different scientific fields such as embedded systems, control systems, operational technology, information technology systems (ITS), and cybernetics. Today critical infrastructures (CIs) (e.g., energy systems, electric grids, etc.) and other CPSs (e.g., manufacturing industries, autonomous transportation systems, etc.) are experiencing challenges in dealing with cyberattacks. Major cybersecurity concerns are rising around CPSs because of their ever-growing use of information technology based automation. Often the security concerns are limited to probability-based possible attack …

Evaluation Of Generative Models For Predicting Microstructure Geometries In Laser Powder Bed Fusion Additive Manufacturing, Andy Ramlatchan

Computer Science Theses & Dissertations

In-situ process monitoring for metals additive manufacturing is paramount to the successful build of an object for application in extreme or high stress environments. In selective laser melting additive manufacturing, the process by which a laser melts metal powder during the build will dictate the internal microstructure of that object once the metal cools and solidifies. The difficulty lies in that obtaining enough variety of data to quantify the internal microstructures for the evaluation of its physical properties is problematic, as the laser passes at high speeds over powder grains at a micrometer scale. Imaging the process in-situ is complex …

A Quality Systems Economic-Risk Design Theoretical Framework, Abdallah S. Thefeid

Engineering Management & Systems Engineering Theses & Dissertations

Quality systems, including control charts theory and sampling plans, have become essential tools to develop business processes. Since 1928, research has been conducted in developing the economic-risk designs for specific types of control charts or sampling plans. However, there has been no theoretical or applied research attempts to combine these related theories into a synthesized theoretical framework of quality systems economic-risk design. This research proposes to develop a theoretical framework of quality systems economic-risk design from qualitative research synthesis of the economic-risk design of sampling plan models and control charts models. This theoretical framework will be useful in guiding future …

Deep Learning Object-Based Detection Of Manufacturing Defects In X-Ray Inspection Imaging, Juan C. Parducci

Mechanical & Aerospace Engineering Theses & Dissertations

Current analysis of manufacturing defects in the production of rims and tires via x-ray inspection at an industry partner’s manufacturing plant requires that a quality control specialist visually inspect radiographic images for defects of varying sizes. For each sample, twelve radiographs are taken within 35 seconds. Some defects are very small in size and difficult to see (e.g., pinholes) whereas others are large and easily identifiable. Implementing this quality control practice across all products in its human-effort driven state is not feasible given the time constraint present for analysis.

This study aims to identify and develop an object detector capable …

Efficient Removal Of Lead Ions From Aqueous Media Using Sustainable Sources On Marine Algae, Hannah Namkoong, Erik Biehler, Gon Namkoong, Tarek M. Abdel-Fattah

Electrical & Computer Engineering Faculty Publications

The goal of this project is to explore a new method to efficiently remove Pb(II) ions from water by processing Undaria pinnatifida into immobilized beads using sodium alginate and calcium chloride. The resulting biosorbent was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). Using immobilized U. pinnatifida, we investigated the effect of various factors on Pb(II) ion removal efficiency such as temperature, pH, ionic strength, time, and underlying biosorption mechanisms. For Pb(II) ion biosorption studies, Pb(II) ion biosorption data were obtained and analyzed using Langmuir and Freundlich adsorption models. It …

Systems Statistical Engineering – Hierarchical Fuzzy Constraint Propagation, Hengameh Fakhravar, Hesamoddin Tahami

Engineering Management & Systems Engineering Faculty Publications

Driven by a growing requirement during the 21st century for the integration of rigorous statistical analyses in engineering research, there has been a movement within the statistics and quality communities to evolve a unified statistical engineering body of knowledge (Hoerl & Snee, 2010). Systems Statistical Engineering research seeks to integrate causal Bayesian hierarchical modeling (Pearl, 2009) and cybernetic control theory within Beer's Viable System Model (S Beer, 1972; Stafford Beer, 1979, 1985) and the Complex Systems Governance framework (Keating, 2014; Keating & Katina, 2015, 2016) to produce multivariate systemic models for robust dynamic systems mission performance. (Cotter & Quigley, 2018) …

A Behavioral Model For Simultaneous Event Execution In Sequential Discrete Event System Simulations, Brian David S. Dilinila

Computational Modeling & Simulation Engineering Theses & Dissertations

The sequential execution of simultaneous events in a discrete event system simulation can cause unexpected behavior in a system. Current studies have provided approaches such as applying a priority order for simultaneous events. However, this is still a problem because executing simultaneous events in sequential order can still lead to two issues of simultaneous event conflicts: the case where simultaneous events cause changes to state variables required by other simultaneous events and the case where two or more simultaneous events cause changes to the same state variables. The objective of this thesis is to develop a behavioral model as a …

Authentication Schemes' Impact On Working Memory, Janine D. Mator

Psychology Theses & Dissertations

Authentication is the process by which a computing system validates a user’s identity. Although this process is necessary for system security, users view authentication as a frequent disruption to their primary tasks. During this disruption, primary task information must be actively maintained in working memory. As a result, primary task information stored in working memory is at risk of being lost or corrupted while users authenticate. For over two decades, researchers have focused on developing more memorable passwords by replacing alphanumeric text with visual graphics (Biddle et al., 2012). However, very little attention has been given to the impact authentication …

Fuzzy Cognitive Map-Based Knowledge Representation Of Hazardous Industrial Operations, Francesco Longo, Antonio Padovano, Letizia Nicoletti, Caterina Fusto, Mohaiad Elbasheer, Rafael Diaz

VMASC Publications

Hazardous industrial operations are highly stochastic, still human-dependent, and risky. Operators working in such an environment must understand the complex interrelation between several factors contributing to safe and effective operations. Therefore, being able to predict the effects of their actions on provoking or mitigating possible accidents is crucial. This study aims to utilize fuzzy cognitive maps (FCM) to model the expert’s reasoning about occupational health and safety (OHS) in confined space. This knowledge is used by operators to build their mental models. The developed FCM displays all the possible incidents of a confined space and links these incidents with all …

Adaptive Task Allocation In Automated Vehicles, Skye Taylor, Bin Hu, Jing Chen

Psychology: Interdisciplinary Research in Behavioral Sciences of Transportation Issues

Adaptive task allocation is used in many human-machine systems and has been proven to improve operators’ monitoring and/or performance with automated systems. However, there is little knowledge surrounding the benefits of adaptive task allocation in automated vehicles. In this study, participants were presented with media depicting driving scenarios of both low and high workload at two levels of automation. The participants reported which tasks they felt comfortable allocating to themselves or to the automated system in each driving scenario, as well as whether they would conduct the task allocation manually or have the automated system automatically allocate the tasks. The …

Effective Project Management And The Role Of Quality Assurance Throughout The Project Life Cycle, Monier Madison Ouabira, Hengameh Fakhravar

Engineering Management & Systems Engineering Faculty Publications

Quality is a fundamental requirement in effective project management. Effective project management entails a steady focus on quality management as well as achievement of all user requirements as defined during the requirements engineering phase of project implementation. Quality assurance must be executed throughout the project development cycle as a new normal in reducing errors and challenges during project development. Conducting quality assurance throughout the project development cycle has many benefits to both the project as well as the project development team. Understanding the research approach to use is critical in achieving high-quality findings in projects. There is a need to …

An Investigation On The Effectiveness Of A Problem Structuring Method In A Group Decision-Making Process, Ying Thaviphoke

Engineering Management & Systems Engineering Theses & Dissertations

There is no shortage of methods to address messy problems. A messy problem is a system of problems with multiple stakeholders who may hold different views of what is feasible or desirable. Decision-makers in a messy problem are prone to committing an error – especially the Type III error. One of the ways to mitigate the chance of committing the error in a messy problem is to reach a group consensus. Problem Structuring Methods (PSM) are the collections of participatory modeling methods that aim to tackle a messy problem. Despite the positive reports, literature indicates some challenges and criticisms of …

Parametric Study Of Residual Stresses In Wire And Arc Additive Manufactured Parts, Hisham Khaled Jamil Abusalma

Mechanical & Aerospace Engineering Theses & Dissertations

Wire and Arc Additive Manufacturing (WAAM) is a cost-effective additive manufacturing process due to its capability to fabricate large metal parts with high deposition rate and low equipment cost. Although this method is gaining popularity in manufacturing industry, more research is needed to understand process parameters’ effects on residual stress (RS) distribution and part distortion. As such, a 3D thermo-elastic-plastic transient model was established in ABAQUS and employed to investigate the effect of process parameters such as the torch speed, the deposition power and the interlayer dwell time on RS distribution and distortion in WAAM part. The numerical model utilized …

A Quest To Identify The Emerging Leadership Skills In Vuca World And Investigation Of Their Applications In Various Organizational Levels And Security Environments, Ali Can Kucukozyigit

Engineering Management & Systems Engineering Theses & Dissertations

The theoretical framework of this research is based on “skills approach” that emphasizes the leader’s capabilities (skills, knowledge, and capabilities) that can be learned, taught, and fostered. VUCA (Volatile, Uncertain, Complex and Ambiguous) environment is chosen as the focal point of this research as the leadership skills are extracted from studies referring to such environment. Although the acronym is dominantly used in management and business domains, the military also uses it to describe the complex operational environments like in Iraq and Afghanistan. The identification of individual leadership skills and delivering the right skill, at the right time, to the right …

Application Of Theory Of Constraints (Toc) In Managing Project Information Constraints, Ferdinand Z. Prantl

Engineering Management & Systems Engineering Projects for D. Eng. Degree

The scope of this doctoral project is the non-traditional application of Drum-Buffer-Rope (DBR) from the area of Theory of Constraints (ToC) in mitigating disruption in distribution facilities during phased upgrades caused by information constraint. The relevance of this project is that industrial equipment upgrades pose a significant risk of disrupting the operation of automated distribution facilities. It is partly due to a very high expected availability rate, as well as tight coupling with other upstream and downstream elements of the larger supply chain network. As a consequence of disruption in this scenario, losses incurred not only within the facility being …

Effects Of Transparency And Haze On Trust And Performance During A Full Motion Video Analysis Task, Sarah C. Leibner

Psychology Theses & Dissertations

Automation is pervasive across all task domains, but its adoption poses unique challenges within the intelligence, surveillance, and reconnaissance (ISR) domain. When users are unable to establish optimal levels of trust in the automation, task accuracy, speed, and automation usage suffer (Chung & Wark, 2016). Degraded visual environments (DVEs) are a particular problem in ISR; however, their specific effects on trust and task performance are still open to investigation (Narayanaswami, Gandhe, & Mehra, 2010). Research suggests that transparency of automation is necessary for users to accurately calibrate trust levels (Lyons et al., 2017). Chen et al. (2014) proposed three levels …

Development And Initial Evaluation Of A Reinforced Cue Detection Model To Assess Situation Awareness In Commercial Aircraft Cockpits, Aysen K. Taylor

Engineering Management & Systems Engineering Theses & Dissertations

Commercial transport aircraft of today vary greatly from early aircraft with regards to how the aircraft are controlled and the feedback provided from the machine to the human operator. Over time, as avionics systems became more automated, pilots had less direct control over their aircraft. Much research exists in the literature about automation issues, and several major accidents over the last twenty years spurred interest about how to maintain the benefits of automation while improving the overall human-machine interaction as the pilot is considered the last line of defense.

An important reason for maintaining or even improving overall pilot situation …

Quantifying Impact Of Cyber Actions On Missions Or Business Processes: A Multilayer Propagative Approach, Unal Tatar

Engineering Management & Systems Engineering Theses & Dissertations

Ensuring the security of cyberspace is one of the most significant challenges of the modern world because of its complexity. As the cyber environment is getting more integrated with the real world, the direct impact of cybersecurity problems on actual business frequently occur. Therefore, operational and strategic decision makers in particular need to understand the cyber environment and its potential impact on business. Cyber risk has become a top agenda item for businesses all over the world and is listed as one of the most serious global risks with significant financial implications for businesses.

Risk analysis is one of the …

Optimization Of Automated Guided Vehicles (Agv) Fleet Size With Incorporation Of Battery Management, Ahmed Hamdy

Engineering Management & Systems Engineering Theses & Dissertations

An important aspect in manufacturing automation is material handling. To facilitate material handling, automated transport systems are implemented and employed. The AGV (automated guided vehicle) has become widely used for internal and external transport of materials. A critical aspect in the use of AGVs is determining the number of vehicles required for the system to meet the material handling requirements.

Several models and simulations have been applied to determine the fleet size. Most of these models and simulations do not incorporate the battery usage of the vehicles and the effect it can have on the throughput and the number of …

Reliability Estimation Of Reciprocating Seals Based On Multivariate Dependence Analysis And It's Experimental Validation, Chao Zhang, Rentong Chen, Shaoping Wang, Yujie Qian, Mileta M. Tomovic

Engineering Technology Faculty Publications

Accurate reliability estimation for reciprocating seals is of great significance due to their wide use in numerous engineering applications. This work proposes a reliability estimation method for reciprocating seals based on multivariate dependence analysis of different performance indicators. Degradation behavior corresponding to each performance indicator is first described by the Wiener process. Dependence among different performance indicators is then captured using D-vine copula, and a weight-based copula selection method is utilized to determine the optimal bivariate copula for each dependence relationship. A two-stage Bayesian method is used to estimate the parameters in the proposed model. Finally, a reciprocating seal degradation …

Natural Resources Governance Employing Blockchain-Based Decision-Making, Farinaz Sabz Ali Pour, Adrian Gheorghe

Engineering Management & Systems Engineering Faculty Publications

Natural resources are essential structures of socio-economic systems which shape the well-being of humanity, environment, and the economy. Human actions have become the critical responsibility for environmental changes and pressuring many planetary boundaries. Having a systematic approach can provide a governance platform including the inherent characteristics of the resource, the historically established form of use, and transaction costs. A natural resource governance framework is developed by applying Blockchain technology as the primary goal of this study to regulate and manage the extraction and trades. Blockchain technology provides a distributed concurrency monitoring system for sustainable resource management. Persistent and pervasive cooperation …

A Framework For Executable Systems Modeling, Matthew Amissah

Engineering Management & Systems Engineering Theses & Dissertations

Systems Modeling Language (SysML), like its parent language, the Unified Modeling Language (UML), consists of a number of independently derived model languages (i.e. state charts, activity models etc.) which have been co-opted into a single modeling framework. This, together with the lack of an overarching meta-model that supports uniform semantics across the various diagram types, has resulted in a large unwieldy and informal language schema. Additionally, SysML does not offer a built in framework for managing time and the scheduling of time based events in a simulation.

In response to these challenges, a number of auxiliary standards have been offered …

A Representation Of Tactical And Strategic Precursors Of Supply Network Resilience Using Simulation Based Experiments, Yaneth C. Correa-Martinez

Engineering Management & Systems Engineering Theses & Dissertations

Modern supply chains are becoming increasingly complex and are exposed to higher levels of risk. Globalization, market uncertainty, mass customization, technological and innovation forces, among other factors, make supply networks more susceptible to disruptions (both those that are man-made and/or ones associated with natural events) that leave suppliers unavailable, shut-down facilities and entail lost capacity.

Whereas several models for disruption management exist, there is a need for operational representations of concepts such as resilience that expand the practitioners’ understanding of the behavior of their supply chains. These representations must include not only specific characteristics of the firm’s supply network but …

Transforming Yekaterinburg Into A Safe, Resilient-Smart And Sustainable City, S. A. Timashev, V. N. Alekhin, L. V. Poluyan, I. Fontanals, A. Gheorghe

Engineering Management & Systems Engineering Faculty Publications

The initiative (since 2014) project described in this paper is a product of a joint innovative research and implementation effort of the Civil Engineering and Architecture Institute, Ural Federal University, the Science and Engineering Centre "Reliability and Safety of Large Systems and Machines", Ural Branch Russian Academy of Sciences (both Yekaterinburg), Start-up OptiCits, Barcelona, Spain and the Old Dominion University, Norfolk, VA, USA. The project is based on using the MAICS convergent technology [1] to create a versatile multi-purpose tool for optimizing the science and art of risk based governance of resilience-smart and sustainable city infrastructure and communities operating in …

Implementation Of A Multi-Criteria Decision Analysis (Mcda) Toolkit To Aid In Ranking Naval Mission Vessel Combinations With Uncertainty, Andrew R. Miller

Engineering Management & Systems Engineering Theses & Dissertations

United States (U.S.) military bases have largely been constructed outside of the contiguous United States (OCONUS) due to the need of close support logistics for conflicts and wars. In contrast, military bases within the contiguous United States (CONUS) have been constructed mostly due to economic and other related monetary factors. In addition to monetary concerns for the placement of military bases (specifically naval bases), there exists tactical, environmental, cultural, climate, logistical, and geographical issues that need to be fully considered before deciding on a naval installation location and the vessels to be stationed there. I will present a new toolkit …

Impact Of A Localized Lean Six Sigma Implementation On Overall Patient Safety And Process Efficiency, Luvianca G. Gil-Moreno

Engineering Management & Systems Engineering Theses & Dissertations

Continuous quality improvement tools have been widely used in the Healthcare Industry to increase efficiency and patient safety as well as to reduce cost. This research explores the impact of a Lean Six Sigma (LSS) process improvement initiative on the overall process efficiency and patient safety in the Labor and Delivery (L+D) units of a large hospital provider. This study focuses on the application of a modeling and simulation methodology to investigate the influence of a localized process improvement intervention on the overall L+D unit output by considering patient flow, system capacity, and unit performance. The simulation models capacity profiles …

Simulation And Optimization Of Ant Colony Optimization Algorithm For The Stochiastic Uncapacitated Location-Allocation Problem, Jean-Paul Arnaout, Georges Arnaout, John El Khoury

Engineering Management & Systems Engineering Faculty Publications

This study proposes a novel methodology towards using ant colony optimization (ACO) with stochastic demand. In particular, an optimizationsimulation-optimization approach is used to solve the Stochastic uncapacitated location-allocation problem with an unknown number of facilities, and an objective of minimizing the fixed and transportation costs. ACO is modeled using discrete event simulation to capture the randomness of customers’ demand, and its objective is to optimize the costs. On the other hand, the simulated ACO’s parameters are also optimized to guarantee superior solutions. This approach’s performance is evaluated by comparing its solutions to the ones obtained using deterministic data. The results …