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Assessing Impacts of Large-Scale Change Events on the Transportation Infrastructure and Its Users
Get PDFTransportation infrastructure systems (TISs) form the backbone of modern society. They not only support worldwide materials flows in supply chain (SC) operations, but also individuals in their daily personal trips. Throughout time and in recent years, events, such as flooding, planned activities, including major rehabilitation projects, and technological advancements, such as 5G, autonomous vehicles, have arisen with large-scale impact on TISs and their operation. However, existing infrastructure management is based on historical trajectories of climate or economic patterns, and impacts from new events on TISs are understudied. To facilitate TIS management for a changing world and understand the impacts of these change events on TISs at scale, this dissertation proposes methodologies needed to create impact analysis tools for three categories of change events: (1) SC restructuring to support the reshoring of the manufacturing of nationally critical products and improve national resilience; (2) large-scale maintenance and rehabilitation plans for improving the condition of multi-modal transportation offerings in a city; and (3) climate change effects on changed greenhouse gas (GHG) emissions emanating from impacts to roadway networks with adaptation seeking to mitigating the impacts on transportation. Techniques from supply chain design, multi-modal transportation network flow modeling, discrete-event simulation geographic analysis through geographic information systems, traffic assignment, and economic analyses are employed in addressing these problems. The dynamics of locations and flows in supply chains, diverse user experiences under large maintenance action plans in multi-modal settings, and climate adaptations under stochastic, heterogeneous climate change events are modeled. Application of these methods on case studies shows the significance of the impact of all three types of events on TISs and the communities they serve. Additionally, the dissertation shows that decision-induced events (e.g., supply chain restructuring) bring overall benefits that outweigh their negative consequences on the community. On the other hand, the implementation of adaptive measures can be a cost-effective approach in mitigating the adverse effects of externally induced events on transportation infrastructure and communities. This dissertation provides a deeper understanding of the benefits and ramifications of major SC restructuring to support increased domestic production for the nation, rehabilitation plans that recognize the needs of diverse, multi-modal users in urban, multi-modal environments, and an ability to quantify changes in GHG emissions from traffic operations resulting from climate change and needed adaptations
Ground-based light curve follow-up validation observations of TESS object of interest TOI 4620.01
Get PDFThe Transiting Exoplanet Survey Satellite (TESS) is a space telescope for NASA's Explorer program, designed to search for exoplanets using the transit method in an area 400 times larger than that covered by the Kepler mission. During its first two years in orbit, the TESS spacecraft concentrated its gaze on several hundred thousand specially chosen stars, looking for small dips in their light caused by orbiting planets passing between their host star and us. Because of the low spatial resolution of its cameras, TESS is expected to detect several false positives (FPs). It can identify as NEB (Nearby Eclipsing Binary), BEB (Blended Eclipsing Binary) or EB (Eclipsing Binary).We use AIJ(AstroImageJ) to find the TOI 4620.01 and create the lightcurve. We found that the brightness of the planet tends to decrease around the predicted time. After that we identify there is a transit
Transient Dynamics in Electroconvection
Get PDFThis thesis describes the analysis of transient dynamics, in multiple contexts, with an emphasis on electroconvection in liquid crystals. Transient dynamics arise when a system is not in steady state; colloquially, when a system is in a transient state, it means the system will not repeatedly return near to its current position. This can be due to the initial conditions of the system, or due to changes in the driving forces or environment of the system that are unrelated to the system’s internal dynamics. Transients are traditionally very challenging to analyze quantitatively, as most dynamical systems metrics require steady state for multiple observations of the dynamics, and to average out the effects of noise or rarely visited regions. The analysis of transients is currently mostly done by ignoring the transient state. If the signal is broken up, the system can be assumed to be in steady state during a short period. This approach worked well on electrical signals generated from the hippocampus of rats while navigating a maze, where more advanced dynamical methods were used to characterize the signals. However, this method did not work on an observed transient of interest in electroconvecting liquid crystals. To analyze this data, a new method of treating transients was developed. By collecting several transients in the same region of phase space, an estimation of the system’s behavior in that region can be done. The region is broken into a tensor bundle, a mathematical structure which allows us to systematically make linear approximations of the system along a chosen trajectory. With this framework, it is also possible to remove a degree of freedom from the estimation problem, as the direction along which the system is traveling, the neural direction, is fundamentally different from the other directions. This framework allows for the quantitative analysis of transient systems from data; providing a quantifiable measure of nonlinearity along the trajectory, as well as metrics for how different nearby transients will be at the end of the trajectory. This differs from standard short time Lyapunov Exponents, which entangle information about spread of arrival times and spread in arrival location. This is demonstrated on the transient of interest in electroconvecting liquid crystal
Resilient Hierarchical Routing for Wireless Networks
Get PDFMy research involves performance engineering techniques for increasing network availability and resiliency in the presence of mobility for Wireless Sensor Networks (WSN) with limited energy resources. Application areas of such WSN deployments range from Industrial Internet of Things (IoT) to public services, such as monitoring environmental conditions across large public works projects. Application areas that involve uncoordinated collection by mobile agents lead to a perturbation of the network to support the emergent, and changing, routing tree rooted at the mobile sink. These applications are not well supported by the standard routing protocol for Low Power and Lossy Networks (LLNs), the Routing Protocol for Low-Power and Lossy Networks (RPL). In light of issues with reliability within RPL under mobility, I developed the Hierarchical network of Observable devices with Itinerant Sinks Transporting data (HOIST) to address this problem using a hierarchical framework. In HOIST, sinks utilize mobility to bridge multiple, geographically segregated fields, while enabling data observers to perform simultaneous real-time assessments of network resources. My approach increased the scalability of individual deployment areas while insulating the collecting devices from routing changes due to sink mobility. While effective at increasing the scale of deployments and the geographic reach of collection centers, the unpredictable movement of mobile collectors led to a decrease in network throughput in the devices on the same DAG as the mobile sink. To account for changes in environmental noise and for network congestion, I further developed the Reliable network of Observable devices with Itinerant Sinks Transporting Data (ROIST) protocol architecture as a reliability-focused extension of the HOIST protocol architecture. ROIST addresses these factors by leveraging the end-to-end, bi-directional communications of HOIST and incorporating flow-control with autonomic adjustments to independently account for congestion and noise, leading to a much higher success ratio across network transmissions. While HOIST and ROIST address the challenges of reliability, another outstanding problem exists with regards to the protection of these resource-constrained devices themselves. One of the most critical attack vectors against such WSN devices is one that targets their energy conservation. A representative device on a pair of AA batteries might otherwise last for years with proper radio duty cycling, but may be drained in a matter of hours under a Distributed Denial of Service (DDoS) attack against the network. Even with the protections of security under RPL, one class of traffic, multicast, permeates the protections to be routed through, causing radios across the network to activate as each router forwards the traffic to the far corners of the network. To protect against this, I developed the Secure, Agile RPL multiCAST (SARCAST) system, using an adaptive Moving Target Defensive (MTD) approach to protect this multicast control traffic and, therefore, protect the sanctity of the energy reserves across a HOIST network by preventing malicious multicast control traffic from spreading. My research contributes to the field by extending the scalability and resilience of RPL, by facilitating end-to-end, bi-directional communications to RPL, by insulating WSN devices from routing changes induced by the presence of a mobile sink, by autonomically adjusting for the conditions of the network through flow-control extensions, and by providing security to multicast control traffic to protect such resource-constrained devices from energy-draining attacks
Using Blockchain in Literary Studies
Get PDFThis work reviews literary studies in a digital environment by exploring conversations concerning the digital humanities, then introduces the intersection of literature and blockchain technology and theory. The aim is to navigate Blockchain within the humanities, specifically literary studies and to further investigate if the application of blockchain can provide sustainable and manageable solutions for the limitations of institutional access. This thesis explores blockchain's deployment across various domains and highlights how specific characteristics of this disruptive technology can resolve issues involving trust, funding, access, and the preservation of materials in literary studies. By investigating current conversations related to blockchain and fields of study similar to literary study, I disseminate an appropriate thesis to theorize the future integrity and shortcomings of blockchain technology in literary studies. With the blend of Artificial Intelligence with blockchain technologies is to encourage the use of blockchain theology and technology for the future application in literary studies
The Use of Morphophonological Cues in Noun Processing: The Case of the Arabic Definite Article
Get PDFListeners use a variety of cues in the speech signal to aid them in identifying nouns. For instance, English speakers use the phonological distinction between a and an to facilitate processing of following nouns (Nozari & Mirman, 2016; Gambi et al., 2018). Listeners’ use of cues is also modulated by the identity of the talker: listeners are less likely to use cues in nonnative talkers’ speech (Bosker et al., 2014; Schiller et al., 2020). Using visual-world eye-tracking, the current study explored native listeners’ use of morphophonologi-cal cues on the Arabic definite article in native- and foreign-accented speech. The Arabic definite article /ʔal-/ provides at least three morphophonological cues to the identity of a following noun. First, the coda /l/ assimilates to following coronal consonants but not to noncoronal consonants (Coronal condition: /ʔaddulfin/ “the dolphin” vs. s/ʔalbab/ “the door”). This assimilation carries two additional sub-phonemic cues depending on the coronal onset: coarticulation associated with emphatics (Emphasis condition: /ʔaˤsˤsˤaruχ/ “the rocket” vs. /ʔassullam/ “the ladder”) and longer pre-voicing associated with voiced stops (Voicing condition: /ʔattut/ “the berries” vs. /ʔaddud/ “the worms”). In two experiments, participants saw picture-pairs accompanied by auditory instructions in Modern Standard Arabic to click on one of them. In Informative trials, the two pictures’ names differed in their initial consonants (/ʔaˤsˤsˤaruχ/ “the rocket” vs. /ʔassullam/ “the ladder”). In Uninformative trials, initial consonants were the same (/ʔaˤsˤsˤaruχ/ “the rocket” vs. /ʔaˤsˤsˤaqr/ “the falcon”). In Experiment 1, participants listened to native-accented Arabic and in Experiment 2, they listened to foreign-accented Arabic. If listeners use the available cues, they should look at the target image earlier and/or longer in informative than uninformative trials. If foreign-accented speech disrupts language processing, cue use will be more evident in Experiment 1 than in Experiment 2. Fixation latency and proportion looks-to-target were measured and analyzed. As predicted, in Experiment 1, mixed effects models showed shorter latencies and higher accuracy in informative than uninformative trials in the Emphasis condition and shorter latencies in the Coronal condition. In Experiment 2, models revealed shorter latencies in the Emphasis condition and higher accuracy in the Coronal condition. No statistically significant effects were found in the Voicing condition for either experiment. These results suggest that native listeners use some of the morphophonological cues on the Arabic definite article to facilitate noun processing. However, the cue use depended on the condition and the identity of the talker. Moreover, unlike previous findings that listeners do not rely on phonological cues in foreign-accented speech, the current results show that foreign-accented speech reduces phonological cue use but does not completely block it. Thus, the current study provides some insights on the use of small phonemic and sub-phonemic article-related cues in noun processing including morphophonological processes of assimilation and coarticulation as well as adds to our understanding of the effects of foreign-accented speech on online language processing in general and on Arabic processing in specific
Application of Artificial Neural Networks to Early-Stage Hull Form Design
Get PDFWith increasingly inexpensive computational resources, big data and machine learning is more available and approachable than ever before. Many industries are moving toward including big data analytics in their current processes and having success using machine learning techniques to improve existing systems and methods. The drive within the naval architecture community over the last few decades towards set-based design and design space exploration has resulted in increasingly large and more readily obtainable sets of ship design data. This research focuses on coupling state-of-the-art in machine learning techniques with increasingly available ship design data in order to improve the hull form design process. A framework for efficiently and effectively developing a feedforward network (FFN) and Convolutional Neural Networks (CNNs) with datasets created within existing ship design software is developed. A novel approach for using Convolutional Neural Networks (CNNs), which are primarily used for image recognition tasks and other models that require spatial reasoning, is used to approximate the resistance of a hull form. The CNNs are given the (X, Y, Z) value of the hull control point coordinates instead of the traditional (Red, Blue, Green) values of image pixels. This new method for generating surrogate models is compared to conventional surrogate model methods as a function of regression error and training sample size. The CNNs offer an efficient computation of the partial derivative of the movement of each control point with respect to the objective function, which is the coefficient of resistance in this study. This method for developing CNNs and other types of Artificial Neural Networks (ANNs) and then computing the gradient of the objective function with respect to the design variables is implemented with a simple gradient-decent method to improve the hull designs. In addition, the use of CNNs to learn the design problem sequentially, over the course of multiple and varying design projects, developing a long-term memory of hull form design is considered. A sensitivity analysis of the network performance with respect to sample size and architecture is presented to demonstrate the robustness and feasibility of this application of ANNs
The Abandoned Mine Land Program: Examining Public Participation in Decision-Making
Get PDFFor centuries, coal extraction and production provided low-cost energy that powered the American economy and produced damage in its wake, leaving thousands of acres of land unreclaimed, transforming landscapes, and disturbing natural ecology (Dixon & Bilbrey, 2015; Zipper & Skousen, 2021). Currently, an estimated 5.5 million people in the Appalachian region live within one mile of an Abandoned Mine Land (AML) site. These sites can pose serious hazards to public health, safety, and the environment while also offering opportunities for public and community participation in the restoration of damaged lands and economic development on abandoned mine sites (Larson, 2022). No studies have been done to determine how states and tribes in the AML program engage the public in decision-making. We conducted a review of State and Tribal Reclamation Plans and Annual Evaluation Reports from 2015-2019, an in-depth case study analysis of four AML states, and disseminated a survey to community groups in the Appalachian region. We found that while AML states and tribes heavily rely on traditional methods of public engagement such as public meetings, hearings, and comment periods, many AML states and tribes were also actively engaged in activities within their community. We found two postures towards engagement: reactive, in which the state or tribe provides information after decisions have been made, and proactive, in which states or tribes attempt to integrate public involvement into the AML decision-making structure. Finally, we found that major barriers to public participation include a lack of information and transparency around AML decision-making and the opportunities for public engagement. We recommend increasing the information and opportunities available to nonprofits and community groups in the region to mitigate this barrier to ensuring effective public participation
Tribological Characterization of Traditionally and Additively Manufactured Inconel 625 Superalloys at Elevated Temperatures
Get PDFThis work is embargoed by the author and will not be publicly available until December 2025.Additive manufacturing is an upcoming scientific technology that offers an edge over the current manufacturing processes with shorter lead time, freedom to design complex geometries, and reduction of waste, thus increasing performance and efficiency. This increased performance and efficiency can lead to a cost saving of billions of dollars, for example, in jet engines' fuel consumption while lowering their carbon emission, or in gas turbines by increasing their energy conversion efficiency. These superalloys are used as aero-engine and gas turbine components, valves, heat exchangers, and control rods in nuclear reactors, and joints in several energy and transportation applications. For instance, nickel-based superalloys constitute over 50% of the total weight of a gas turbine engine. Such applications usually involve very high temperatures wherein some of the nickel-based components like joints, valves, and heat exchangers undergo inherent vibration leading to the relative motion between components at the interfaces causing surface wear. Nickel-based alloys are known to exhibit different age-hardening behavior at different temperatures. As the call to integrate additively manufactured parts into mainstream applications grows stronger, it becomes ever so important to study their mechanical and tribological behavior across a range of temperatures starting at room to elevated temperatures, and possibly enhance their performance through special surface engineering techniques. The research objective of this dissertation is to evaluate the high-temperature fretting wear of additively manufactured and traditionally manufactured Inconel 625 superalloys and to uncover the underlying mechanisms responsible for the tribological behaviors. Further, this study plans to quantitively determine the effect of two surface enhancement processes on the microstructural evolution and high-temperature fretting wear of Inconel 625. Accordingly, this dissertation is comprised of three parts. The first part is the study of the high-temperature tribological behavior of additively manufactured Inconel 625 samples in contrast to the traditionally manufactured samples. Advanced microscopy and microstructural characterizations were carried out to correlate the manufacturing processes to the tribological behaviors. Here, in particular, we focus on high temperature (up to 700 ºC) fretting wear characteristics. The second part is focused on improving the fretting wear behavior of the samples with surface enhancement processes of shot peening and laser peening. Detailed advanced microstructural characterization was performed to understand how peening processes affect the microstructure of traditionally manufactured Inconel 625 and subsequently its fretting wear properties. This includes the investigation of the samples to understand the change in microstructure and crystal structure due to the diffusion of metals/metal oxide and grain boundary segregation due to the high-temperature wear phenomenon. The third part is an in-depth study of microstructural changes due to the peening processes on the additively manufactured samples. The study of fretting wear behavior of the additively manufactured peened samples is a continuation of this work and included in future scope. Studies involving fretting fatigue behavior at elevated temperatures will also improve the understanding of the additive manufacturing process.2025-12-1
Three Essays on the Culture of Markets and Peace
Get PDFWhat enables us to peacefully live with one another? This dissertation studies how the market is a space for mutual understanding, social coordination, and peace. The essays explore insights from mainline political economy and the Austrian economic tradition to better understand how our cultural environments shape the emergence of peaceful societies. The first chapter, “Economic Calculation and Interpretation,” examines how entrepreneurs understand their worlds and make decisions with the aid of interpretive devices, technologies, or instruments that mediate meaning. The second chapter “Entrepreneurial Pathways to Peacemaking,” examines why socially embedded entrepreneurs are more attuned to the unique problems and circumstances that stand in the way of peace. The last chapter, “The Market as a Space for Building a Peaceful Society,” explores the spaces and media of the market that enable us to practice habits which build peaceful societies