Digital Commons Network^™

Learning Evolution Modeling Of Multi-Cycle Nested Cloud Manufacturing Service Ecosystem, Fang Li, Deyu Zhou, Gang Wang, Guangjun Liu, Qi Hu

Journal of System Simulation

Abstract: In view of the lack of comprehensive consideration of the individual adaptability changes of enterprises caused by the collaborative governance mechanism among multiple manufacturing units and the overall evolution trend of the system in existing learning evolution models, this proposed a learning evolution model of multi-cycle nested cloud manufacturing service ecosystem. At the micro level, the adaptive linkage decision-making among multiple manufacturing units within the enterprise was achieved in the individual layer through the nesting of planning-readiness-execution-assessment (PREA) loops and OODA loops; at the macro level, the closed-loop simulation of the individual layer, organizational layer, and social layer was …

Study On Transient Electric Field Of Insulated Rail Joints In High-Speed Railway Stations Based On Dissado-Hill Model, Junli Li, Youpeng Zhang

Journal of System Simulation

Abstract: The transient electric field distribution of insulated rail joints in high-speed railway stations under lightning impulse voltages is critical to their normal operation. Under lightning impulse voltages, considering the relaxation polarization of the insulated rail joint material, a frequency-domain mathematical model of its transient electric field was established. Based on Dissado-Hill model, the measured frequency-domain dielectric spectra were fitted and analyzed to reveal the microstructural characteristics of insulated rail joints and the interaction characteristics between microscopic particles during the polarization process. The results indicate that the relative permittivity of insulated rail joints decreases with the increasing harmonic frequency of …

Intelligent Evaluation Method For Regional Air Superiority Based On Graph Convolutional Neural Network, Peng He, Yubo Tang, Jingde Liu, Yujia Tian

Journal of System Simulation

Abstract: To address the dual challenges of the lack of quantification standards and sparse air combat samples in the superiority evaluation of modern air combat, an intelligent evaluation method for regional air superiority based on a graph convolutional neural network was proposed. The spatial grid method was employed to encode the air situation of the entire battlefield airspace into a new data representation, namely the air superiority matrix. A novel air superiority quantification model was applied to quantify the air superiority label values of spatial grids, and four key operational capabilities closely related to air superiority contention were selected as …

Sensorless Control Of Pmsm Based On An Improved Super-Twisting Sliding-Mode Observer, Shiyu Chen, Xinmin Chen, Xionglong Hu, Heng Wang, Yepeng Han, Jiajie Chen

Journal of System Simulation

Abstract: To address the chattering in back electromotive force estimation and the gain mismatch across a wide speed range when using a conventional super-twisting sliding-mode observer in the sensorless control system of a permanent-magnet synchronous motor, this paper proposed an improved adaptive-gain super-twisting sliding-mode observer. A linear correction term was introduced into the super-twisting algorithm and integrated with a gain adaptation law based on speed feedback, enabling the system to achieve finite-time convergence and high-precision back electromotive force estimation over a wide speed range. A variable-gain adaptive complex-coefficient filter was constructed to effectively suppress the harmonic components in the observed …

Line Spectrum Enhancement Technology Based On Second-Order Vector Hydrophone, Zhengkai Wang, Yirong Yu, Qing Hu

Journal of System Simulation

Abstract: In view of the problem of limited detection of line spectrum signals in low signal-to-noise ratio underwater environments, a spatial-temporal cooperative line spectrum enhancement technology based on a two-dimensional second-order vector hydrophone was proposed. A receiving signal model of the two-dimensional second-order vector hydrophone was established to clarify the spatial characteristics of its output signals. For spatial signal processing, the signals from each channel of the vector hydrophone were fused to suppress noise, and a channel combination method with high spatial directivity gain was proposed to achieve spatial processing gain. For temporal signal processing, an adaptive line spectrum enhancer …

Dodaf-Opm-Sd Cross-Layer Automated Mapping Method Based On A Unified Semantic Bridge, Lei Cheng, Gang Xiao, Binbin Wang, Siming Peng, Haozhe Liang, Xiangwu Gong

Journal of System Simulation

Abstract: To address the problems of the inability of DoDAF views to directly drive simulations and the insufficient cross-layer semantic alignment and consistency verification, a DoDAF-OPM-SD cross-layer semantic automated/semi-automated mapping and verification method was proposed in this paper. Targeting tactical/operational-level problems dominated by "conservation+feedback+time delay", the proposed method reduced manual mapping under expert adjudication based on a "minimal executable view set". The object-process methodology served as a semantic bridge to map architectural elements into the stock-flow-feedback structures of system dynamics; semantic embedding disambiguation, integer programming harmonization, and K-nearest neighbor parameter completion were integrated; end-to-end traceability was connected through traceability identifiers, …

Design And Implementation Of Hdrt Real-Time Simulation System, Huiji Zheng, Guangsen Wang, Qing Liu, Kang Wang, Zhiwei Wang, Zhenyu Zhang, Shuo Wang, Zhu Liu

Journal of System Simulation

Abstract: In view of the real-time simulation requirements of large-scale complex systems such as power electronics, a hidden dragon real-time(HDRT) simulation system was developed. The strict time constraints of simulation tasks were guaranteed based on a resource-dedicated real-time scheme, supporting fixed-step and multi-rate simulations from the second level to the hundred-nanosecond level. A hybrid CPU-field programmable gate array(FPGA) architecture was adopted to accelerate computation. The system could utilize multiple simulators for parallel simulation and realized microsecond-level real-time data interaction between simulators through a dedicated PCIe switch. A single simulator could be expanded through I/O interface equipment, supporting a maximum input …

Numerical Simulation Of Water Tank Solidification In A Firefighting Aircraft Under High-Altitude Cold-Soak Conditions, Guanmian Liu, Zhihang Cheng, Hejun Qin, Kangzhi Yang, Qing Wen, Kun Gao

Journal of System Simulation

Abstract: A systematic numerical simulation study was conducted to address the issue of internal water tank solidification in firefighting aircraft under high-altitude low-temperature conditions. Based on computational fluid dynamics methods, a solidification-melting model considering fluid-structure interaction heat transfer and phase change processes was adopted. Through reasonable simplification of the complex geometric model, a quasi-three-dimensional computational model suitable for engineering analysis was developed. The influence laws of key parameters, including high-altitude cold-soak temperature, ground initial water temperature, and cold-soak time, on the freezing characteristics of the water tank were investigated. Combining with the parameter influence laws, a safety criterion using the …

Combat Effectiveness Evaluation Of Anti-Ship Missiles For Intelligent Autonomous Recognition, Long Zhang, Xuanming Feng, Zhen Lei, Bo Yang, Ying Wang

Journal of System Simulation

Abstract: To address the core issues of poor adaptability of static fusion strategies in existing recognition models, as well as the simplistic evaluation system and its disconnection from dynamic confrontation requirements, a practical four-dimensional evaluation system encompassing "recognition accuracy, antijamming stability, decision timeliness, and modal complementarity" was constructed, and an operational effectiveness composite index (OECI) capable of dynamically adapting to tactical scenarios was proposed. A multimodal dynamic attention fusion network (MDA-Net) for anti-ship missiles in complex confrontation environments was designed. Through heterogeneous feature decoupling, dynamic weighting of cross-modal attention, and a hierarchical gating decision mechanism, the autonomous evaluation and adaptive …

Infrared Image Generation Method Based On Improved Cyclegan, Qiqi Jin, Xiang Zhang, Li Gao, Lin Zhang, Junliang Yan, Peiyao Li

Journal of System Simulation

Abstract: To address the problems in current infrared image generation such as insufficient contrast between target and scene, excessively large discrepancies from real scenes, indistinct thermal source features, and great difficulty in constructing measured infrared image datasets, an improved CycleGAN-based infrared image generation method was proposed. By optimizing the network structure of the generator and adding a non-local module and a CBAM convolutional attention mechanism into the generator, the extraction capability of CycleGAN for infrared features was enhanced, enabling the network to capture the subtle features of targets more accurately; a perceptual loss function was introduced to improve the detail …

Tier 2 Literacy Interventions In Low-Income Schools: Implications For Breaking The Cycle Of Poverty, Morgan Koch

Dissertations

This study examined the development of a mastery-based Tier 2 reading and writing curriculum prototype designed to improve the coherence and consistency of literacy intervention in high-poverty educational settings. Using the Design Thinking process, stakeholder feedback from educators, administrators, instructional staff, and parents informed the development of the prototype through the Empathy, Define, Ideate, Prototype, and Test phases. The curriculum was evaluated by 15 education professionals through a mock implementation, usability survey, and focus group discussion. Findings suggested that participants perceived the prototype as practical, well organized, and supportive of more efficient and consistent Tier 2 literacy instruction, while also …

Effective Traffic Routing Under Disastrous Events Through Machine Learning, Eric Itemuagbor

All Theses

Disastrous events such as hurricanes, wildfires, and floods routinely disrupt transportation networks, preventing emergency response, evacuation, and the delivery of critical supplies. Conventional optimization-based routing methods offer strong theoretical guarantees but cannot scale and are often too slow to support time-sensitive decision-making during a disaster, while prior machine learning approaches to disaster routing have largely prioritized prediction accuracy over inference speed and data efficiency. This thesis investigated whether lightweight machine learning models can deliver both competitive routing accuracy and superior inference speed when trained on limited data, addressing a practical gap between existing research and real-world deployment needs.

The road …

Cost-Effectiveness Evaluation Of Artificial Intelligence-Assisted Chest Radiograph Interpretation For Tuberculosis Screening In Rural Health Units In The Philippines, Harold Henrison C. Chiu, Bryan Christopher C. Lao, Gloanne C. Adolor

Graduate School of Business Publications

Background: Tuberculosis remains a major public health burden in the Philippines, where diagnostic delays are amplified by limited radiology capacity in rural health units (RHUs) and geographically isolated and disadvantaged areas (GIDAs). Computer-aided diagnosis (CAD) using artificial intelligence (AI)-assisted chest radiograph interpretation may shorten the screening pathway and reduce reliance on scarce specialist readers. However, its economic value for RHUbased tuberculosis screening has not been fully evaluated.
Methods: We developed a decision-tree cost-effectiveness model in Microsoft Excel 365 to compare AI-assisted chest radiograph interpretation with conventional manual radiologist or teleradiology interpretation among a theoretical annual cohort of 1,000 presumptive tuberculosis …

Evaluation Of General Voronoi Diagram Decomposition For Harmonic Fields In Navigation Of Dynamic Environments, Franco Abullarade

Master's Theses

Harmonic potential fields provide provably minimum-free navigation, but any change to the workspace geometry invalidates the field and forces a costly global recomputation, typically restricting them to static environments. This thesis extends the harmonic map framework of Vlantis et al., which maps the free workspace onto a unit disk and uses an atlas of per-region transformations, to dynamic indoor settings. First, we replace their manually annotated room partition with an automatic decomposition based on the Generalized Voronoi Diagram, allowing the atlas to be built from an arbitrary occupancy grid in an automated way. Second, we introduce a localized repair procedure …

Final Report, Luke Murphy

Goal 8: Decent Work and Economic Growth

No abstract provided.

Advancing Sdg 9 Through Ai-Powered Waste Diversion, Ally Murphy

Goal 9: Industry, Innovation and Infrastructure

No abstract provided.

Effects Of Bidisperse Gold Nanoparticles On Near-Infrared Surface-Enhanced Raman Spectroscopy (Sers) In Quick-Freezing-Induced Gold Nanoparticle Aggregates (Qfiaas), Elissa M. Dojka

Forensic Science Master's Projects

Gold nanoparticle (AuNP) aggregates formed via rapid freezing in liquid nitrogen exhibit strong near-infrared (NIR) plasmonic coupling. These quick-freezing-induced AuNP aggregates (QFIAAs) form moderately sized, colloidally stable structures that remain suspended for over three months, supporting a variety of analytical applications. Mechanistically, QFIAA formation arises from the confinement of nanoparticles and ions within advancing ice grain boundaries during freeze-concentration. This mechanical crowding promotes extreme physical proximity while simultaneously elevating local ionic strength, which screens electrostatic barriers to drive the assembly of dense, tightly coupled plasmonic networks.

This study investigates the plasmonic and surface-enhanced Raman scattering (SERS) behavior of bidisperse QFIAA …

Analysis Of Terpenes In Cannabis Flowers Using Gas Chromatography Via Headspace-Solid Phase Microextraction (Hs-Spme), Hannah I. Bergner

Forensic Science Master's Projects

As cannabis commercialization grows, rigorous profiling of cannabinoids, terpenes, and chemical contaminants is legally required for industry standardization and consumer safety. Terpenes are highly volatile components that dictate the unique aromatic profiles and therapeutic properties of cannabis via receptor pathways. This project focused on a gas chromatography-flame ionization detector/mass selective detector (GC-FID/MSD) combined with headspace-solid phase microextraction (HS-SPME) sampling to analyze terpenes present in four cannabis samples. Cannabis samples were tightly sealed in vials (10 mL) and heated to vaporize terpenes in the headspace above the samples, followed by the extraction of the vaporized terpenes using a polydimethylsiloxane (PDMS)-coated SPME …

Hkc07 - Bayesian Conspiracy Theorists? Equivocal Signals And Persistent Polarization, Javier A. Granados Samayoa, Timothy Hyde

Oberlin College Kasper Economics and Business Working Paper Series

Conspiracy beliefs are the subject of a rich literature in psychology, which explains them through personal dysfunction. The corresponding economics literature is scant. We offer a demand-side model of belief in specific conspiracy theories with no biases, misspecification, or strategic manipulation. A conspiracy, by its nature, generates equivocal evidence about its own existence, because the same strength that produces more to detect also produces better concealment. We model belief in a specific conspiracy theory as learning about the strength 𝑞 of a cabal, a stand-in for the secretly coordinating actors of any conspiracy theory. In the baseline the cabal influences …

Global, Regional, And National Burden Of Hiv/Aids, 1990–2023, With The Estimated Burden Attributable To Intimate Partner Violence And Forecasted Impacts Of Funding Cuts Through 2030: Results From The Global Burden Of Disease Study 2023, Austin Carter, Meixin Zhang, Bricia G. Trejo, Megan Verma, Edmond D. Brewer, Dylan Lasher, Jiawei He, Regina Mae Villanueva Dominguez, Amanda Movo, Jianing Ma, Olivia Angelino, Hans J. Elliott, Carolyn M. Shyong, Ian E. Cogswell, Abdullah, Hasan Aalruz, Mulatu Abageda, Ukachukwu O. Abaraogu, Qamar Abbas, Samar Abd Elhafeez, Ashraf Nabiel Abdalla, Emad M. Abdallah, Reda Abdel-Hameed, Siddig Ibrahim Abdelwahab, Wakgari Mosisa Abdisa, Meriem Abdoun, Arman Abdous, Zahir Vally

All Works

Background Despite a general improvement in the HIV burden over the past two decades, gendered social determinants including intimate partner violence (IPV) continue to affect women's vulnerability to HIV, which could be further exacerbated as resources dwindle over the coming years. Our study aimed to quantify recent trends in the HIV burden, the magnitude of the HIV burden associated with IPV, and the potential impact of declining financial support globally. Methods Using the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2023 framework, we estimated annual HIV incidence, prevalence, and mortality for 204 countries and territories from 1990 …

Determining The Role Of Maumee River Sediments In Microbial Nitrogen Transformations And Net Fluxes, Ashlyn Stanalonis

Master's Theses

The Maumee River watershed is the largest of any river feeding into the Laurentian Great Lakes and is primarily comprised of agricultural land uses. Most cultivated crops require fertilizer applications to sustain growth and productivity. Fertilizer runoff is a major source of nutrient loading to the river, and total nitrogen (N) and phosphorus (P) inputs contribute to eutrophication and cyanobacterial blooms in the western basin of Lake Erie. This study aimed to characterize Maumee River sediments as net N sinks or sources to the western basin and evaluate N removal efficiency (a valuable ecosystem service) to determine if river sediments …

Computer Self-Efficacy As Predictor Of Electronic Information Resources Use By Academic Staff Of Selected Polytechnics In South-West, Nigeria., Temitope Adeleke Osisanwo Dr, Yemisi Tomisin Babalola Prof

Library Philosophy and Practice (e-journal)

Electronic information resources have become a significant portion of library resources available to academic staff for teaching and research purposes. However, studies suggest that their use has not been fully optimized by academic staff at polytechnics located within South-West, Nigeria. This could be attributed to the low level of self-effectiveness of technology among the academic staffs. In light of this, this study aimed to examine the relationship between computer self-efficacy and the usage of electronic information resources among polytechnics academic staff in South-West, Nigeria.

A survey research design was used for this study, while 3,807 academic staff members were selected …

Paleolimnology And Diatom Taxonomy From Lake Tanganyika, Sristika Adhikari

All-Inclusive List of Electronic Theses and Dissertations

Lake Tanganyika is one of the world's largest freshwater ecosystems, supporting rich aquatic biodiversity and providing several ecosystem services to surrounding communities. Environmental changes such as rising lake surface temperatures, pollution, and land-use alterations threaten the lake’s sustainability. This research examines spatial and temporal variations in nutrient dynamics and primary productivity of Lake Tanganyika using diatom assemblages from multiple locations. Our findings indicate reduced nutrient levels and longer stratification periods in the lake’s central basin during most of the Common Era, as indicated by a remarkable increase in the relative abundance of long, needle-shaped planktonic Nitzschia species. In the southern …

Lessons From The Club Homeschool Capstone: Testing, Data Discipline, And The Computer Science Curriculum, Shane Brown

University Honors Theses

This thesis looks at the CLUB Homeschool Capstone project to argue that Portland State University's Computer Science curriculum should introduce testing and data quality discipline earlier and more intentionally than it does now. As team lead of a seven-person team, I coordinated sprint planning, communicated with the sponsor, and developed custom Discourse plugins that enhanced an existing forum platform instead of creating a separate application database, as requested by the sponsor. The project's requirements document called for a formal testing plan, but our team lacked the practical experience to implement one. This gap became evident through my internships as a …

Modulating Linear Frequency Modulated Pulses To Send Communications Data In A Bistatic Sar Scenario, Jarren T. Worthen

All Graduate Theses and Dissertations, Fall 2023 to Present

Synthetic aperture radar (SAR) is the technology that enables the creation of images using radar waves, allowing images to be formed regardless of weather. In bistatic SAR a radar platform uses a radar pulse from a separate platform to form an image. It is important that these radar systems are able to communicate with each other. Rather than wasting energy and space flying with a separate communication system, the radar systems could use the already existing SAR system to send data between each other while still forming SAR images. The work of this thesis is to show how very simple …

Multispecies Weed Detection Using Unmanned Aerial Vehicles And Deep Learning Object Detection Models In Utah Forage Crop Corn Field, Utsav Bhandari

All Graduate Theses and Dissertations, Fall 2023 to Present

Weeds cost global agriculture over $32 billion annually and reduce crop yields by nearly one-third. Current weed control relies heavily on spraying herbicides uniformly across entire fields, leading to herbicide-resistant weeds, environmental harm, and increasing costs for farmers. A smarter approach is detecting weeds from the air and spraying only where they are present. This could dramatically reduce herbicide use while protecting crop yields. This thesis developed a complete system for identifying weeds in corn fields using drone-captured images and artificial intelligence. Working in commercial forage corn fields in Cache Valley, Utah, high-resolution aerial images were collected and used to …

Visualizing The Phase Space Of Two Interacting Spherical Magnets Via Lagrangian Descriptors, Matthew Pontius

All Graduate Theses and Dissertations, Fall 2023 to Present

This thesis studies the motion of one spherical magnet sliding on another fixed spherical magnet. Although the setup is simple, the resulting motion can range from regular and predictable to chaotic as the energy increases. To understand this behavior, mathematical tools are used to visualize how all possible motions are organized in phase space. These methods reveal patterns such as stable regions, repeating motions, and chaotic trajectories. The results show how order and chaos coexist in this system and provide insight into how small changes in the initial conditions can lead to very different outcomes.

Impact Of Chronic Stress And Nutrition On Functional Connectivity And Neural Networks In Young Kichwa Children From The Ecuadorian Amazon Rainforest, Matthew L. Cook

All Graduate Theses and Dissertations, Fall 2023 to Present

Early childhood is a critical period for brain development. Positive and negative experiences during this time can have lasting effects on learning, health, and well-being. However, most research on children’s brain development has been conducted in wealthy, industrialized nations, leaving important gaps in our understanding of how children develop in other cultural and environmental contexts.

This study examined brain development in Indigenous Kichwa children living in two rural communities in the Ecuadorian Amazon Rainforest. The goal was to better understand how chronic stress and nutrition may influence a child’s developing brain during early childhood. Children participated in noninvasive brain assessments …

Drought And Diet Breadth: Does Insect Specialization Influence Herbivory When Plants Are Under Stress?, Jakob Palmer

All Graduate Theses and Dissertations, Fall 2023 to Present

Climate change will alter precipitation worldwide, causing more frequent and severe drought events worldwide. Drought affects many ecological processes, including plant-herbivore interactions, which are critical to biodiversity and ecosystem health. A variety of plant characteristics can influence herbivory – such as how hairy, nutritious, or toxic a leaf is – and drought has been shown to alter many of these traits. Unique characteristics of herbivore species are also important: herbivores can either feed on a variety of plants (generalists) or a group of closely related plants (specialists). Specialists can cope with traits of the plants they eat, while generalists are …

A Social-Ecological Systems Approach To Integrating Outdoor Recreation And Black Bear Management: A Michigan Case Study, Megan Dorothy Stone

All Graduate Theses and Dissertations, Fall 2023 to Present

Outdoor recreation sits at the intersection of social and ecological systems, representing one of the primary ways in which humans directly interact with their natural environment. As a result, outdoor recreation management must balance providing high-quality outdoor recreation opportunities while simultaneously protecting natural resources in protected areas. Balancing these concurrent management goals has become more challenging in recent years as participation in outdoor recreation increases. This can lead to numerous negative impacts on the environment, such as wildlife disturbance. In this study, I explore the challenges and opportunities for collaboration between managers of outdoor recreation and black bears in the …