A. James Clark School of Engineering
Permanent URI for this communityhttp://hdl.handle.net/1903/1654
The collections in this community comprise faculty research works, as well as graduate theses and dissertations.
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Item ACCELERATING RESTORATION THROUGH INFORMATION-SHARING: UNDERSTANDING OPERATOR BEHAVIOR FOR IMPROVED MANAGEMENT OF INTERDEPENDENT INFRASTRUCTURE(2024) Yazdisamadi, Mohammadreza; Reilly, Allison C.; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This dissertation examines the roles that organizations and individuals play in restoring interdependent infrastructure following disasters through three studies. In the first study, we focus on how operator heuristics affect the collective restoration speed of three interdependent infrastructure (electric power, chilled water, and IT networks). We do this by developing a novel framework that embeds an interdependent infrastructure network within an agent-based model that mimics the decisions and patterns observed of actual operators. The study sheds light on how coordination and information exchange by separate infrastructure parties affect decisions and thus restoration outcomes. In the second study, we examine recovery times and total unmet demand for the same three interconnected infrastructure systems assuming a variable fraction of node removals. The work is decomposed by the extent to which operators share information and coordinate strategies, enabling us to identify at what fraction of network failure does coordination and information sharing become beneficial. Our study indicates that prioritizing restoration based on node centrality produces the speediest recovery. We also show that communication among organizations may improve collective performance by as much as 50%. Our final research project uses a serious game, Breakdown, focused on restoration of interdependent infrastructure to assess whether engineering graduate students gain a deeper appreciation for the complexity of interdependent infrastructure and socio-technical systems more broadly. This is the first serious game designed to emphasize the value of cooperation, communication, and strategy in times of crisis in the field of interdependent infrastructure. As a result of playing Breakdown, graduate students demonstrated statistically significant improvements in engineering decision-making under uncertainty and sociotechnical systems concepts. As a result of this dissertation, the interdependent infrastructure community gains insight into (1) how individual operators' behavior influences the speed at which interdependent infrastructure systems recover; (2) how policies and procedures, like sharing information and cooperating, can help improve outcomes; and (3) the ways to teach graduate engineering students about socio-technical systems effectively. Using an agent-based model simulation, it quantifies the effects of human behavior, communication, and cooperation on recovery outcomes. By using a serious game, Breakdown, it proposes an innovative way to teach graduate engineering students about socio-technical systems.Item ANALYZING BID PRICES QUANTITATIVELY AND PROTEST DECISIONS QUALITATIVELY TO REDUCE PROJECT-RELATED DISPUTES IN ADVANCE(2022) Kim, Young Joo; Skibniewski, Miroslaw J; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Parties to a construction contract can consume significant resources in dealing with project-related disputes. Therefore, it is advantageous for project stakeholders to identify potential issues earlier to avoid such problems as much as possible. This dissertation research explored evidence-based approaches to reduce project-related disputes before commencing construction projects. The research was carried out by examining a cost dataset from a state Department of Transportation that prioritizes the lowest-priced bid and by investigating a bid protest dataset from a Federal Government office that typically prioritizes the best value. With the coefficient of variation of bids as an independent variable of interest, the cost dataset was quantitatively studied using Welch’s t-test, correlation and regression analyses, and the K-nearest neighbors classification. Then, the Government Accountability Office’s decisions on denied bid protests against the U.S. Army Corps of Engineers were qualitatively meta-summarized. The observations showed the limited usefulness of collective intelligence provided by bidders at the time of bid opening in identifying projects likely to experience more significant project cost changes upon completion, as well as the effectiveness of the thematic findings in limitedly helping small businesses fore-test the validity of their cases before filing bid protests. The results could be applied beyond the Architecture, Engineering, and Construction industries as projects occur in all industries and industry sectors.Item Dynamic Traffic Management of Highway Networks(2022) Alimardani, Fatemeh; Baras, John S; Electrical Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Efficient operation of traffic networks via management strategies can guarantee overall societal benefits for both the humans and the environment. As the number of vehicles and the need for transportation grows, dynamic traffic management aims to increase the safety and efficiency of the traffic networks without the need to change the infrastructure of the existing roads. Since the highway networks are considered permanent investments that are expensive to build and maintain, the main scope of this dissertation is to propose traffic flow models and methods to improve the efficiency of the current highway systems without the need to change their infrastructure. When all vehicles in a network are \textit{Human-Driven Vehicles} (HDVs), and changing the infrastructure is either so expensive or impossible, then one reasonable approach to improve the efficiency of traffic networks is through the control of traffic signal lights specially because the behavior of the human drivers cannot be directly controlled. A literature review of highway traffic control demonstrate that \textit{Ramp Metering} (RM) is one of the most commonly used approaches as it improves the network performance in regards to travel time, travel distance, throughput, etc and cost-wise, it is a very economical approach. As such, in this research, the ultimate goal focus is to extend the current literature on traffic managements of highway networks by offering new models and algorithms to improve this field. To reach this goal, the first step is to focus on improving and extending the current traffic flow models. There are two categories of traffic flow models in the literature: First-order models, and Second-order models. Many different extensions of the famous first-order model called the Cell-Transmission Model (CTM) have been proposed throughout the past decades, each one proposed based on different criteria and the specific needs of different applications. In the first part of this dissertation, a performance assessment of the most important extensions of CTM will be performed. Then, based on this evaluation, an extended version of the CTM, called the Piece-Wise Affine Approximation-CTM (\textit{PWA-CTM}), will be offered which will be proven to have better performance regarding the evolution of traffic flow and computation time comparing to the previous versions of this model. In the next step, the focus will be shifted to second-order models as they have better capabilities of modeling the behavior of traffic flow comparing to the first-order models. However, any optimization scheme for highway traffic control based on these models is highly nonlinear and computationally intensive. As such, in this part of the research, a linearization of the famous second-order model called the \textit{METANET} will be offered which is based on PWA approximations and also synthetic data generation techniques. With extensive simulations, it will be shown that this linearized approximation can greatly impact the computational complexity of any optimization-based traffic control framework based on this second-order traffic flow model. Moreover, to have significant traffic management improvements, not only the underlying traffic models, but also the control strategies should be enhanced. The availability of increasing computational power and sensing and communication capabilities, as well as advances in the field of machine learning, has developed \textit{learning-based} control approaches which can address constraint satisfaction and closed-loop performance optimization. In this chapter, \textit{Reinforcement Learning} (RL) algorithms will be investigated to solve the optimal control problem of RM. In the case of RM, RL-based techniques offer a potentially appealing alternative method to solve the problem at hand, since they are data-based and make no assumptions on the underlying model parameters. Towards this direction, it is convenient to study the road model as a multi-agent system of non-homogeneous networked agents. In the following, a novel formulation of the RM problem as an optimal control problem based on a first-order multi-agent dynamical system will be offered. Then, applying policy gradient RL algorithms, a probabilistic policy will be found that solves the ramp-metering problem. The performance of the optimal policy learnt will be investigated under different scenarios to evaluate its efficiency.Item CROSS-INDUSTRY ADOPTION AND SUSTAINABILITY PRACTICES IN FACILITY MANAGEMENT(2022) CHI, JEFF Dajun; Baecher, Gregory; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Propelled by new technology, modern management methodologies, and sustainability movement, the facility industry has become one of the fastest growing business sectors. This dissertation conducts research on facility market growth, cross-industry learning and innovative method adoption, and sustainable facility practices. Multiple research methodologies are employed to examine six propositions. Mixed use of case studies, surveys, interviews, qualitative comparative analysis (QCA), and Grounded Theory with Pre-Post comparisons are applied to study target propositions from multiple angles, draw strengths from one methodology to offset the weaknesses of another, and deliver balanced analyses and arguments. The demands for modern facility management methods, preconditions for new practice adoptions, and risk control in project execution are discussed in reference to case studies. Importance of government involvement and the critical role of corporate policy plays in converting government efforts into results are confirmed with survey responses from industry practitioners and backed by case studies. Current challenges encountered in sustainable facility practices are discussed and the causes of these issues are investigated. Besides survey and case studies, interviews and special topic content research are conducted to explore potential solutions. The collective outcome of the research has established case-based reasoning to support each of six propositions on the determinants of project success.Item LEADERSHIP IN PROJECTS WITH NEW TECHNOLOGY AND UNCERTAINTY(2021) Moschler, Jr., Joseph W.; Baecher, Gregory B.; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Project management continues to evolve as types of projects increase, advancement of technologies available, as well as tools for project management grow in sophistication. A successful project is defined as being completed on schedule, on budget, and delivering the requirements as specified by the customer. Projects with new technologies or with technologies requiring maturation add another dimension and challenge for the project manager. Four factors are identified as integral to project success; leadership, requirements definition, technology usage and maturity, and vision and clear objectives. Three historical projects involving new technologies are evaluated within the context of the four factors: the Lockheed SR-71 Blackbird aircraft, the Hoover Dam project, and Project Apollo. The projects are qualitatively ranked as successful based on the cost, schedule, and delivering requirements criteria. The three projects were successful. Each project ranked strongly in the four factors and remain consistent indicators of potential project success.Item Impacts of COVID-19 on Construction(2020) Alkhalouf, Hala; Skibniewski, Miroslaw; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This research investigates and quantifies the impacts of coronavirus (COVID-19) on the duration and cost of construction projects, focusing specifically on two construction dimensions: supply chain and construction labor productivity. Conclusions on the topic were reached using two methods, namely performing two case studies and using Primavera 6 and Schedule Analyzer software to analyze schedule updates. Each of the case studies utilizes a real-life construction project that was active when the impact of the pandemic was at its peak (April 2020). The data also includes interviews with project managers and progress meeting minutes. Results reveal that COVID-19 has impacted the progress of construction in two ways: 1) delays resulting from the shutdown of the manufacturing facilities and suppliers that state officials deemed non-essential; 2) labor disruptions resulting from restrictions on gatherings, as well as absenteeism of workers who were either sick with COVID-19 or who were avoiding construction sites and preferred to stay home in response to state officials’ recommendations. The results suggest that contractors should request compensable time extensions, as they establish the basis for a legitimate claim that will lead to modifications of the contract time and/or total dollar amount. Future work may investigate the integration of tools and methods during the bidding and construction process that would mitigate the future impact of similar potential situations due to a pandemic or any other force majeure event. Future work may also investigate impacts of COVID-19 on construction sites outside the United States.Item The Communication Solution for Attentional Bias Among Project Decision Leaders during Critical Incident Stress Phase of Crisis(2020) Djolevic, Natalija; Baecher, Gregory; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This research addresses barriers and solutions to crisis communication challenges based on existing crisis communication theories. The theories highlighted and expanded upon are integrated crisis mapping theory (ICM) and situational crisis communication theory (SCCT). Using these two theories, a new theory, attention crisis communication theory (ACCT) is postulated as a solution for attentional bias. Attentional bias is observed in crisis management teams during the onset of the critical incidence phase or at the beginning of a crisis trigger event. Other theories including real options decision theory and networks theory are considered and discussed as potential alternatives to ACCT.Item On Engineering Risks Modeling in the Context of Quantum Probability(2020) Lee, Yat-Ning Paul; Baecher, Gregory B; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Conventional risk analysis and assessment tools rely on the use of probability to represent and quantify uncertainties. Modeling complex engineering problems with pure probabilistic approach can encounter challenges, particularly in cases where contextual knowledge and information are needed to define probability distributions or models. For the study and assessment of risks associated with complex engineering systems, researchers have been exploring augmentation of pure probabilistic techniques with alternative, non-fully, or imprecise probabilistic techniques to represent uncertainties. This exploratory research applies an alternative probability theory, quantum probability and the associated tools of quantum mechanics, to investigate their usefulness as a risk analysis and assessment tool for engineering problems. In particular, we investigate the application of the quantum framework to study complex engineering systems where the tracking of states and contextual knowledge can be a challenge. This study attempts to gain insights into the treatment of uncertainty, to explore the theoretical implication of an integrated framework for the treatment of aleatory and epistemic uncertainties, and to evaluate the use of quantum probability to improve the fidelity and robustness of risk system models and risk analysis techniques.Item Project Scheduling Disputes: Expert Characterization and Estimate Aggregation(2017) Neely, Lauren; Baecher, Gregory; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Project schedule estimation continues to be a tricky endeavor. Stakeholders bring a wealth of experience to each project, but also biases which could affect their final estimates. This research proposes to study differences among stakeholders and develop a method to aggregate multiple estimates into a single estimate a project manager can defend. Chapter 1 provides an overview of the problem. Chapter 2 summarizes the literature on historical scheduling issues, scheduling best practices, decision analysis, and expert aggregation. Chapter 3 describes data collection/processing, while Chapter 4 provides the results. Chapter 5 provides a discussion of the results, and Chapter 6 provides a summary and recommendation for future work. The research consists of two major parts. The first part categorizes project stakeholders by three major demographics: “position”, “years of experience”, and “level of formal education”. Subjects were asked to answer several questions on risk aversion, project constraints, and general opinions on scheduling struggles. Using Design of Experiments (DOE), responses were compared to the different demographics to determine whether or not certain attitudes concentrated themselves within certain demographics. Subjects were then asked to provide activity duration and confidence estimates across several projects, as well as opinions on the activity list itself. DOE and Bernoulli trials were used to determine whether or not subjects within different demographics estimated differently from one another. Correlation coefficients among various responses were then calculated to determine if certain attitudes affected activity duration estimates. The second part of this research dealt primarily with aggregation of opinions on activity durations. The current methodology uses the Program Evaluation and Review (PERT) technique of calculating the expected value and variance of an activity duration based on three inputs and assuming the unknown duration follows a Beta distribution. This research proposes a methodology using Morris’ Bayesian belief-updating methods and unbounded distributions to aggregate multiple expert opinions. Using the same three baseline estimates, this methodology combines multiple opinions into one expected value and variance which can then be used in a network schedule. This aggregated value represents the combined knowledge of the project stakeholders which helps mitigate biases engrained in a single expert’s opinion.Item INFORMATION TECHNOLOGY PROJECTS IN NONPROFIT UNIVERSITY: A PROJECT GOVERNANCE PERSPECTIVE(2016) Ghosh, Soumajit; Cui, Qingbin; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The universities rely on the Information Technology (IT) projects to support and enhance their core strategic objectives of teaching, research, and administration. The researcher’s literature review found that the level of IT funding and resources in the universities is not adequate to meet the IT demands. The universities received more IT project requests than they could execute. As such, universities must selectively fund the IT projects. The objectives of the IT projects in the universities vary. An IT project which benefits the teaching functions may not benefit the administrative functions. As such, the selection of an IT project is challenging in the universities. To aid with the IT decision making, many universities in the United States of America (USA) have formed the IT Governance (ITG) processes. ITG is an IT decision making and accountability framework whose purpose is to align the IT efforts in an organization with its strategic objectives, realize the value of the IT investments, meet the expected performance criteria, and manage the risks and the resources (Weil & Ross, 2004). ITG in the universities is relatively new, and it is not well known how the ITG processes are aiding the nonprofit universities in selecting the right IT projects, and managing the performance of these IT projects. This research adds to the body of knowledge regarding the IT project selection under the governance structure, the maturity of the IT projects, and the IT project performance in the nonprofit universities. The case study research methodology was chosen for this exploratory research. The convenience sampling was done to choose the cases from two large, research universities with decentralized colleges, and two small, centralized universities. The data were collected on nine IT projects from these four universities using the interviews and the university documents. The multi-case analysis was complemented by the Qualitative Comparative Analysis (QCA) to systematically analyze how the IT conditions lead to an outcome. This research found that the IT projects were selected in the centralized universities in a more informed manner. ITG was more authoritative in the small centralized universities; the ITG committees were formed by including the key decision makers, the decision-making roles, and responsibilities were better defined, and the frequency of ITG communication was higher. In the centralized universities, the business units and colleges brought the IT requests to ITG committees; which in turn prioritized the IT requests and allocated the funds and the resources to the IT projects. ITG committee members in the centralized universities had a higher awareness of the university-wide IT needs, and the IT projects tended to align with the strategic objectives. On the other hand, the decentralized colleges and business units in the large universities were influential and often bypassed the ITG processes. The decentralized units often chose the “pet” IT projects, and executed them within a silo, without bringing them to the attention of the ITG committees. While these IT projects met the departmental objectives, they did not always align with the university’s strategic objectives. This research found that the IT project maturity in the university could be increased by following the project management methodologies. The IT project management maturity was found higher in the IT projects executed by the centralized university, where a full-time project manager was assigned to manage the project, and the project manager had a higher expertise in the project management. The IT project executed under the guidance of the Project Management Office (PMO) has exhibited a higher project management maturity, as the PMO set the standards and controls for the project. The IT projects managed by the decentralized colleges by a part-time project manager with lower project management expertise have exhibited a lower project management maturity. The IT projects in the decentralized colleges were often managed by the business, or technical leads, who often lacked the project management expertise. This research found that higher the IT project management maturity, the better is the project performance. The IT projects with a higher maturity had a lower project delay, lower number of missed requirements, and lower number of IT system errors. This research found that the quality of IT decision in the university could be improved by centralizing the IT decision-making processes. The IT project management maturity could be improved by following the project management methodologies. The stakeholder management and communication were found critical for the success of the IT projects in the university. It is hoped that the findings from this research would help the university leaders make the strategic IT decisions, and the university’s IT project managers make the IT project decisions.