SACM - United States of America
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Item Restricted CONTROLLING SURFACE PLASMON POLARITON ACTIVITY THROUGH CONDUCTION ELECTRON MANIPULATION(Saudi Digital Library, 2026) ALANAZI, AHMED DHAHER S; McIlroy, David NGold mesopyramids (Au MPs) fabricated on silicon substrates exhibit an unusual hysteretic optical reflectivity response when subjected to simultaneous optical excitation and externally applied electrical bias. Unlike bulk metallic systems, where electrically induced reflectivity modulation is typically negligible, Au MPs show large and reproducible changes in reflected optical intensity, indicating that the optical response is strongly influenced by interfacial electronic processes beyond those predicted by the classical free electron model. The complex morphology of the Au MP structure, together with its partially embedded Au–Si interface, suggests that the observed behavior is governed by surface plasmon polariton (SPP) activity coupled to dynamic charge redistribution at the metal-semiconductor boundary. Electrical bias sweeping revealed stable hysteresis loops in the optical reflectivity, demonstrating that the optical response depends not only on the instantaneous applied electrical signal but also on the previous charge state of the system. Measurements performed using silicon substrates with different resistivities showed that the optical response is controlled primarily by electrical current rather than applied voltage, indicating that carrier injection and interfacial charge transport govern the observed behavior. Time dependent measurements further revealed both leading and lagging optical responses relative to the applied voltage, suggesting the presence of fast and slow charge trapping processes that produce an effective RC-like dynamic response at the Au–Si interface. Additional co-illumination and electron-hole pair generation experiments demonstrated that photogenerated carriers in silicon significantly modify the plasmonic optical response of the Au MP, producing measurable shifts in hysteresis behavior and center of mass. These results indicate that conduction electron manipulation near the Au surface can alter the balance between radiative and non-radiative plasmon decay pathways and may influence interaction between multiple plasmonic modes supported by the structure. This work demonstrates a mechanism for actively controlling SPP activity through conduction electron manipulation at a buried Au–Si interface, establishing Au MPs as a promising platform for electrically tunable active plasmonic systems.17 0Item Restricted Automated Motif Indexing On The Arabian Nights(Saudi Digital Library, 2026) Alyami, Ibrahim; Finlayson, MarkThere is a wealth of information that can be obtained in narratives. Cultural information is an example of what we can find. One form that cultural information can take is motifs. A motif is a recognizable recurring element or concept that frequently aids in the development of other literary or narrative elements like theme or mood. The importance of motifs, according to folklorists, is that they classify and locate stories from different cultures using motifs, and follow the evolution of stories across time. Beyond folklore, motifs also appear in news and social media such as tweets, which can tell us a lot about a culture. Until now, motifs are extracted manually from stories. A folklorist goes through a long and complicated process to identify motifs. Moreover, folklorists must have enough background in a culture to be able to understand motifs and extract them. I propose to develop a system that automatically detects thousands of motifs from text. In this dissertation, I focus on motif indexing: detecting and extracting motif expressions from narratives using an existing motif index as a guide. My thesis has four aims: first, to find, collect, examine, and preprocess the dataset which consists of a list of motifs and folktales. Second, to build a baseline model to automatically detect and understand motifs in text using a handful list of motifs to generate candidate motif expressions for dataset construction. Third, to annotate the dataset, which will be used in training state-of-the-art LLMs. Fourth, to develop a model that automatically detects the entire motif index. The first step of my work is the dataset used to build a culturally aware LLM, including the source of motifs and the narratives that contain them. I showed how we processed both sources and narratives, and my work on motif classification (Simple to Complex motifs). The second step is a large-scale annotation of 58,450 positive and negative motif expressions generated from the baseline system. The third step is fine-tuning state-of-the-art LLMs to automatically index motifs from narratives. The fine-tuned LLM achieved strong performance compared to the baseline models, which highlights the necessity of continued training with larger datasets that contain cultural elements, in order to improve AI systems’ ability to understand culture and its many facets. Finally, I describe using the fine-tuned model to automatically index 5,362 motif expressions from the Arabian Nights. This work demonstrates automatic motif indexing at the scale of an entire motif index. This dissertation contributes resources and methods that support building AI systems that are more culturally aware by enabling large-scale detection and indexing of motifs in narrative text.11 0Item Restricted THE MONODROMY GRAPH ASSOCIATED TO THE DYNATOMIC CURVE(Saudi Digital Library, 2026) Almutarrid, Mohammed Abdulaziz; Doyle, JohnThis dissertation studies the affine dynatomic modular curves Y_1(n) and Y_0(n), which parametrize unicritical polynomial maps f_c(x) = x^d + c of degree d > 2 together with their periodic orbits of period n, as well as their smooth projective completions X_1(n) and X_0(n). The central objective is to determine for which primes p the curve X_0(n) remains geometrically irreducible despite having bad reduction modulo p. Morton algebraically characterized the primes of bad reduction for these curves using the discriminant of the primitive parabolic factor D_{n,n} = disc_c(Delta_{n,n}(c)). For the quadratic family f_c(x) = x^2+c, Doyle et al. showed that X_0(n) remains geometrically irreducible modulo p whenever an odd prime p divides D_{n,n} exactly once. In this dissertation, we extend this framework to arbitrary degrees d > 2. Specifically, we prove that if p does not divide d and the p-adic valuation satisfies v_p(D_{n,n}) <= (3d - 4)/2, then X_0(n) is geometrically irreducible in characteristic p. Under this condition, up to 3d - 4 finite branch points may collide modulo p, yet geometric irreducibility is nevertheless preserved. The proof combines complex dynamics and the combinatorial structure of the degree-d Multibrot set to establish the required transitivity of the associated monodromy action.8 0Item Restricted THE USE OF BEHAVIORAL ECONOMICS FOR STRATEGY EXECUTION(Saudi Digital Library, 2026) Alkhars, Ahmed; Dhanaraj, CharlesThis dissertation addresses the persistent "strategy-execution gap," where approximately 60% to 90% of strategic initiatives fail due to a reliance on "rational actor" assumptions that ignore the psychological realities of human behavior. Adopting a two-essay, mixed-methods approach, the research shifts the execution paradigm from structural compliance to the design of "behavioral choice architectures". The first essay utilizes a qualitative multiple- case study of six organizations in the U.S. and Saudi Arabia to deconstruct organizational resistance. It introduces the Influence vs. Resistance Framework, identifying the "Subversive" archetype—high-influence actors who feign agreement while passively stalling implementation—as the most lethal and frequently misdiagnosed threat to execution. Findings suggest that resistance is often rooted in loss aversion, the endowment effect, and status quo bias. The second essay introduces the Behavioral Economics in Execution (BEX) framework, a five- step prescriptive model. Using a policy-capturing experimental design with 33 senior executives (N=1,056 decisions), the study empirically validates five behavioral interventions: piloting with champions, loss-framed score-boarding, public commitments, rigid review cadences, and milestone celebrations. Results provide robust support for the framework revealing that loss- framed KPIs exert the strongest influence on perceived success. The dissertation culminates in an integrated "Behavioral Operating System," providing a scientifically validated "Behavioral Playbook" for leaders to neutralize resistance and transform strategic intent into operational reality.11 0Item Restricted Exploring Saudi English Language Teachers’ Perception in Accommodating the Needs of Students with Dyslexia(Saudi Digital Library, 2026) Alghamdi, Mohammeed; Joshua, KennaThis dissertation explored quantitatively Saudi English language teachers’ perceptions of accommodating students with dyslexia in English as a Foreign Language (EFL) classroom, and examined whether their perceptions differ based on teachers’ years of experience. Social Cognitive Theory framed this study, with a particular focus on teacher self-efficacy (Bandura, 1997). A structured survey was distributed to 169 Saudi EFL teachers teaching in public school. The instrument consisted of a 24-item preparedness scale, which demonstrated high internal consistency (Cronbach’s α = .93). Descriptive statistics were used to address the first question, and a one-way analysis of variance (ANOVA) was used to address the second question of this study. The findings for the first research question indicated that Saudi EFL teachers reported moderate to high levels of perceived preparedness (M = 3.97, SD = 1.27). However, the results of the one-way ANOVA for the second research question showed no significant differences in teachers’ perceived preparedness based on years of teaching experience, F(2, 165) = 1.09, p = .337. These outcomes suggest that Saudi teachers are confident in their ability to accommodate students with dyslexia in their classrooms, yet such confidence does not appear to stem from accumulated teaching experience as a main source of knowledge. The findings of the present study contribute to a growing body of literature highlighting that preparedness to support students with dyslexia in EFL classrooms is influenced more strongly by access to specialized training and relevant knowledge about dyslexia. Given the limited exposure to dyslexia-specific training reported by many teachers in the Saudi context, there is a need for more targeted professional development to support inclusive EFL practices in Saudi Arabia12 0Item Restricted Proxy Detection via Passive Traffic Analysis and Fingerprinting(Saudi Digital Library, 2026) Almutairi, Sultan Saud M; Harfoush, Khaled; Viniotis, IoannisIn this thesis, I study proxy detection in two settings: Internet censorship and application provider access control. Both impose restrictions on users’ access to content and services, and users employ proxies to bypass these restrictions. This interaction forms a continuous cat and mouse game, where advances in evasion drive advances in detection, and vice versa. In the censorship game, detection must work at national scale. The literature identifies a research-to-practice gap. Research proposes methods that are complex and costly to deploy. I take this operational constraint as a design requirement and address the problem from two novel angles. The first angle analyzes the network path to identify practical detection points that censors can leverage. I uncover two previously unexplored detection points: the home router and domestic web-tracking infrastructure. I show how they enable scalable detection. The second angle is the first study to examine circumvention tool architectures from a detection perspective. It reveals a previously unexploited structural property that enables passive detection. This property requires architectural changes to evade. All three methods are passive, obfuscation-agnostic, and designed for deployment at scale. In the application provider game, the server must answer a binary question: is this connection proxied? Residential proxy providers defeat existing detection methods. Their proxy IP addresses are residential and absent from proxy databases. Their global scale allows users to select geographically close proxies and evade RTT-based detection. The proxy runs on a residential device that also generates legitimate traffic. As a result, the connection blends with normal user traffic. I address this problem from two angles. The first is the largest measurement of the residential proxy ecosystem to date, with novel passive device-level fingerprinting. The second is a new detection primitive that exploits a structural property of proxy connections. It detects proxies that IP reputation and RTT-based methods miss. In summary, this thesis makes five contributions across two settings. For Internet censorship, I present three passive detection methods, each with a characterization of countermeasures. For the application provider, I present the largest residential proxy measurement to date and a detection primitive based on cross-layer OS fingerprinting.11 0Item Restricted Assessing Infection Control Practices Among EMS Providers in Prehospital Settings: A Comprehensive Study Examining Compliance and Barriers(Saudi Digital Library, 2026) Alsaleem, Abdulrahman; Lawler, JamerBackground: The Centers for Disease Control and Prevention (CDC) estimates that healthcare-associated infections (HAIs) are responsible for around 1.7 million infections and thousands of deaths every year. These infections have a substantial financial impact, costing the U.S. healthcare system billions annually. Despite the importance of infection control practices in any healthcare setting, there is a substantial gap in research specifically addressing these practices in prehospital settings. Objective: This project addresses this gap comprehensively by exploring infection control practices among emergency medical services (EMS) providers during field operations. The specific aims of this study are (1) Evaluate the level of compliance with infection control guidelines among EMS providers in prehospital settings and (2) Identify barriers and enablers to adherence to infection control guidelines among EMS providers in prehospital settings. Methods: Aim 1: Direct, real-time observations to assess compliance of EMS providers with infection control guidelines during prehospital care and upon arrival at healthcare facilities. To my knowledge, this approach has not been employed before in assessing all relevant infection control practices among EMS providers while collecting demographic and contextual data to investigate meaningful associations. Aim 2: An exploratory mixed method design was utilized to gain a deeper understanding of barriers and enablers influencing infection control among EMS providers in prehospital settings and to examine how demographic and background factors may contribute to these influences. Results: The findings of aim 1 indicate notable inconsistency in IPC compliance; this inconsistency can be explained by demographic and contextual data, as the findings show. Aim 2 findings showed that IPC compliance is influenced by different factors, as providers suggested. Together, these findings represent the first comprehensive assessment of IPC compliance of all relevant IPC practices in prehospital settings based on actual field data, and they offer possible explanations and potential associations to explain the current compliance rates. These project findings could pave the way for further research in this area and also lead to the development of evidence-based strategies to improve infection control practices in prehospital settings.10 0Item Restricted CHARACTERIZATION OF SHEAR STRENGTH AND CRACKING RESISTANCE OF A CHEMICALLY STABILIZED CLAYEY SOIL(2022) Alhawiti, Abdulaziz; Ghabchi, RouzbehImproving the engineering properties of the subgrade soil by means of chemical stabilization is known to enhance the construction conditions in plastic soils and result in a reduction in design thickness requirements of the base, subbase, and wearing course in a layered pavement structure. This can also potentially lead to an increase in pavement life. This study was undertaken to study the effect of hydrated lime and Portland cement used as a stabilizing agents on the strength properties and the cracking resistance of a clayey soil collected from South Dakota. Hydrated lime was mixed with the collected soil by 2%, 3% and 5% and Portland cement was blended at 7%, 9% and 11% by the weight of the soil. Different tests, namely Particle size distribution, Atterberg limits, pH, Proctor test, freeze-thaw (F-T) cycles, unconfined compressive strength, and semicircular bend test were conducted before and after treatment with hydrated lime and Portland cement. The results indicated that use of 1% cement was more effective than 1% lime in improving soil’s shear strength. In general, shear strength of the natural soil was found to become more sensitive to F-T cycles with increasing both Portland cement and hydrated lime contents. The flexural stiffness and fracture energy of the natural soil were found to improve by stabilizing it with both lime and cement. This improvement was more pronounced when Portland cement was used. Reduction in the flexural stiffness and fracture energy of the lime-stabilized soil was found to be more sensitive to F-T cycles than cement-stabilized soil. The only stabilizing agent found to be capable of improving the flexibility index of the natural soil was hydrated lime. Cement-stabilized soil was concluded to be highly brittle and may result in instantaneous propagation of the crack in the whole section after reaching the peak load. Therefore, the use of cement stabilization should be carried out more cautiously to avoid premature crack.7 0Item Restricted UNDERSTANDING MOTOR LEARNING IMPAIRMENTS DURING VISUOMOTOR ADAPTATION AND INTERLIMB TRANSFER IN PEOPLE WITH MULTIPLE SCLEROSIS(Saudi Digital Library, 2026) AlMutairi, Badr; Wang, JinsungMultiple sclerosis (MS) is a chronic neurological disorder characterized by demyelination and neuroaxonal degeneration that can impair motor control and motor learning. Visuomotor adaptation, a type of motor learning, has been widely used to investigate sensorimotor learning capabilities in individuals with various neuromotor impairments, although it has not been studied in people with multiple sclerosis (PwMS). Therefore, I examined the characteristics of visuomotor adaptation, interlimb transfer, and the relative contributions of implicit and explicit learning in this dissertation. Specifically, the purpose of this dissertation was to investigate: (1) visuomotor adaptation with the dominant and nondominant arms in PwMS compared with healthy controls, (2) the pattern of interlimb transfer following visuomotor adaptation in PwMS compared with healthy controls, and (3) the relative contributions of implicit and explicit learning to visuomotor adaptation in PwMS. In Aim I, visuomotor adaptation to a novel visuomotor condition with each arm was examined in 11 PwMS and 20 healthy controls. PwMS demonstrated significantly larger direction errors than controls during the initial stage of adaptation, particularly when adapting with the dominant arm. However, they progressively reduced errors throughout practice and achieved performance comparable to that of healthy controls by the end of adaptation. In contrast, no group differences were observed in terms of final position accuracy. These findings suggest somewhat impaired predictive motor control capabilities but preserved feedback-mediated movement correction abilities in PwMS. In Aim II, the pattern of interlimb transfer following visuomotor adaptation (i.e., adaptation with one arm first, then with the other arm) was examined in the same participants tested in Aim I. Both PwMS and healthy controls demonstrated asymmetrical transfer, with transfer occurring from the nondominant arm to the dominant arm, but not in the opposite direction. Importantly, the overall transfer pattern observed in PwMS was similar to that of healthy controls, indicating that interlimb transfer mechanisms remain largely preserved in PwMS. In Aim III, 20 PwMS adapted to a novel visuomotor condition in one of two experimental conditions: one in which the visuomotor rotation condition was introduced gradually (i.e., implicit learning), and the other in which it was introduced abruptly from the beginning of the adaptation session. Specific information regarding the perturbation was provided to the latter condition (i.e., explicit learning). Participants in the gradual/implicit condition demonstrated greater savings and better retention during readaptation than those in the abrupt/explicit condition. These findings suggest that explicit learning conditions, often considered beneficial for learning in neurotypical individuals, may not have the same positive effects on PwMS. Collectively, this dissertation demonstrates that PwMS exhibit deficits in predictive feedforward motor control while maintaining relatively preserved feedback-mediated control and interlimb transfer mechanisms (aims I and II). Furthermore, it demonstrates that implicit learning conditions lead to more effective learning and more durable motor memory formation than explicit learning in PwMS. These findings advance our understanding of motor learning capabilities in PwMS and provide important implications for the development of rehabilitation interventions that emphasize repetitive practice, error-based sensorimotor learning, and implicit learning strategies in this population.8 0Item Restricted Preserving Saudi’s Modern Heritage: The Case of SOM, Yamasaki, and Transnational Modernism(Saudi Digital Library, 2025) AlMater, Shereen; Dolkart, Andrew SThe Kingdom of Saudi Arabia, as we know it today, has a long and culturally rich history. That history has been safeguarded by the Saudi Ministry of Culture since its establishment, starting with the humble beginning of the Antiquity and Museums Agency of 1964. Over the past few years, not only has the Ministry of Culture expanded, but it has also generated new cultural disciplines to include under its governance. What started as a simple agency developed into eleven diverse cultural commissions that one ministry governs. As a result, preservation efforts expanded discipline-wise to render a more holistic image of Saudi Arabia’s cultural heritage. During the era of the Antiquity and Museum Act of 1972, the focus was primarily on preserving vernacular architecture and archeological sites of importance. However, now that the focus of the Ministry has broadened, preliminary efforts have been extended to preserve the plethora of cultural disciplines that exist in the entirety of the country. This thesis will analyze how current preservation policies and frameworks influence the Modern Heritage of a certain era in Saudi Arabia’s development. The era in reference is often referred to as the Leap, a period of architectural and developmental significance in the history of the country that began in the 1960s and reached its peak in the 70s. The Leap, which was rendered a leap due to the surge in development following the commercialization of petroleum, birthed monumental Modernism in Saudi Arabia. The significance of that architecture has been historically neglected in books that historicize the Modernist era, despite the unique circumstances that brought it about. This research highlights the significance of transnational Modernism in Saudi Arabia by relaying its petroleum-embedded history. Using the work of SOM and Yamasaki as a basis, this thesis aims to analyze how current preservation policies and initiatives are successful or lacking in their interaction with Modern Heritage, and consequently, the potential benefits and challenges of preserving transnational Modernism.15 0