Digital Commons Network^™

A Maximum Energy Release Rate Computational Framework For Fatigue Crack Trajectory And Life Prediction Under Mixed-Mode Proportional And Nonproportional Loading, Nahla Helmy Matar

Theses and Dissertations

The problem of mixed-mode fatigue crack growth has been a persistent research challenge. The determination of fatigue crack propagation direction directly impacts the safety and integrity of components and structures, making it crucial in various industrial applications, including welded drilling pipes, aerospace, and automotive engineering. Unlike uniaxial loading, mixed-mode cracks tend to change direction frequently (kinking), and nonproportional loading adds to the complexity of the problem. This research aims to estimate the crack propagation direction and fatigue crack life in linear elastic materials subjected to mixed-mode (I+II) loading conditions under proportional or non-proportional cyclic loading. Numerical software was developed based …

Sar Ship Detection Based On Shallow Feature Guidance, Chenxu Xia, Peng Chen, Ya Zhang, Ying Li

Journal of Marine Science and Technology–Taiwan

Maritime ship detection is of great significance for both military security and civilian applications. Synthetic Aperture Radar (SAR), with its all-weather and all-day imaging capability, plays a vital role in maritime surveillance. Nevertheless, SAR ship targets typically appear small in scale, embedded in complex backgrounds, blurred at boundaries, and easily confused with near-shore features, which pose substantial challenges for accurate detection. To address these issues, we propose a SAR ship detection network that integrates dual enhancements of small-object representation and edge information. The network introduces two key components: the Small Target Refine Pyramid (STRP) to strengthen shallow feature representation for …

Extending Geometric Acoustic Ray Tracing To Multi-Room Environments: A Case Study On Gunshot Sound Transmission Between Adjacent Rooms, Tyler Ton

Theses and Dissertations

Accurate localization of gunshots in multi-room building environments remains a challenging problem in acoustic forensics and public safety applications. Existing approaches model sound propagation within a single room, neglecting the transmission of acoustic energy through walls and other building materials. This thesis presents a study on modeling multi-room gunshot acoustic transmission, combining geometric ray tracing with structural acoustic transmission-loss modeling to generate impulse responses for two horizontally adjacent rooms separated by a shared wall, providing a foundation for future inter-room gunshot localization work. The proposed system uses GSound-SIR, a geometric acoustics engine, to simulate sound propagation in both of the …

Lrq-Solver: A Transformer-Based Neural Operator For Fast And Accurate Solving Of Large-Scale 3d Pdes, Peijian Zeng, Guan Wang, Haohao Gu, Xiaoguang Hu, Tiezhu Gao, Zhuowei Wang, Aimin Yang, Xiaoyu Song

Electrical and Computer Engineering Faculty Publications and Presentations

Solving large-scale PDEs on complex three-dimensional geometries remains a central challenge in scientific and engineering computing, often due to expensive pre-processing stages and high computational overhead. We present Low-Rank Query-based PDE Solver (LRQ-Solver), a physics-integrated deep learning framework for efficient CAE simulations of complex three-dimensional geometries in CAD-driven design analysis. Built upon the Parameter-Conditioned Lagrangian Modeling (PCLM) that embeds physical consistency into the learning process and the Low-Rank Query Attention (LR-QA) module that reduces attention complexity from O(N2) to O(NC2+C3) via covariance decomposition, LRQ-Solver supports multi-configuration analysis within iterative design workflows. On two benchmark datasets, it achieves a 28.6% error …

Spatial Markov Equilibrium Models For Taxi Services: Driver Decision, Search Friction, And Locational Pricing, Yanchao Liu

Industrial and Systems Engineering Faculty Research Publications

This paper develops a modeling framework for stochastic multi-agent systems and applies it to equilibrium and pricing analysis in urban taxi markets. Travel demand is represented as a trip network and embedded in a Markov chain that captures both locational and in transit taxi states, with transition dynamics reflecting trip durations, search frictions, spatial competition, and drivers’ perceptions of long-term value. The framework features a parametric Markov chain with endogenous transition probabilities and a behavioral model in which agents’ decisions depend on anticipated long-term rewards. We establish equilibrium existence and examine two locational pricing schemes that align individual incentives with …

Spatiotemporal Variations Of Tidal Asymmetry Along The Coast Of Taiwan: Characteristics And Implications, Ting-Chieh Lin, Tai-Wen Hsu, Tzu-Chun Huang, Chun-Yuan Lin

Journal of Marine Science and Technology–Taiwan

This study presents the first systematic investigation into the spatiotemporal characteristics and evolutionary trends of tidal asymmetry along the coast of Taiwan from 2003 to 2022, employing a moving window method combined with the S_TIDE toolbox.  By quantifying the skewness of the Main Tidal Asymmetry Combinations (MTAC) and their temporal variations, the study reveals significant regional disparities between the eastern and western coasts.  The western coast is primarily dominated by the M2-M4 combination, with the northwestern region exhibiting a flood dominance pattern and the southwestern region characterized by ebb dominance.  Conversely, the eastern coast, attributed to its open topography and …

Reliable Performance Analysis Of Polyurea Coatings Used In Offshore Wind Turbines, Yu-Chang Lin, Yen-Fu Liu, I-Ming Pan, Ming-Yuan Lin, Kang-Yu Liao, Hung-Hua Sheu, Hung-Bin Lee

Journal of Marine Science and Technology–Taiwan

This study explores the weather resistance, mechanical properties and corrosion resistance of polyurea coatings in marine environments. The relevant analysis results can be used as a reliability assessment of offshore wind turbine structural coatings during their service life under the influence of marine environments. The long-term experiment uses seawater and 70°C thermal aging conditions as coating reliability assessment items. The microstructure of the samples that have been immersed in seawater for a long time and thermally aged is observed using a scanning electron microscope (SEM). The results show that the surface of the 100 and 125 series polyurea coatings is …

A Resilience Early Warning Assessment Of The Maritime Supply Chain: A Case Study Of China’S New Energy Vehicle Exports, Xiuqian Chen, Liangyong Chu, Mengyao Wang, Jiayin Du, Yiming Zhang, Xiyao Xu

Journal of Marine Science and Technology–Taiwan

Enhancing resilience through early warning is a critical strategy for mitigating disruption risks in the maritime supply chain (MSC). This study proposes a novel early warning assessment framework to determine the resilience of the MSC. It is referred to as a resilience early warning system. An evaluation index system for shipping enterprises is developed based on four dimensions: withstand capacity, adaptive capacity, learning capability, and the external environment. A resilience assessment model that uses the Bayesian best-worst method (BBWM) and the extension cloud model (ECM) is established to quantify MSC resilience. An early warning evaluation model based on a Bayesian …

Between Blockchain And Black Markets: South Africa's Legal Readiness For Crypto-Driven Cyberfraud, Sagwadi Mabunda, Yassin Chande

Communications of the IIMA

This paper examines whether the proliferation of cryptocurrency-facilitated fraud warrants a reclassification of the terrestrial crime of fraud into the distinct statutory offence of cyberfraud under South African law. Engaging with established fraud typologies — exit scams, Initial Coin Offering (ICO) scams, Ponzi schemes, pump-and-dump schemes, and market manipulation — the article tests their definitional fit against both the common law of fraud and section 8 of the Cybercrimes Act 19 of 2020. Through a hypothetical composite scenario combining multiple fraud typologies, the article demonstrates that whilst cryptocurrency significantly amplifies the reach and complexity of fraudulent schemes, it functions primarily …

Parametric Study On The Plastic Hinge Length Of Precast Concrete Columns With Grouted Sleeve Connections, Rizky Tri Amalia, Harun Alrasyid

Journal of Sustainable Construction Materials and Technologies

The use of precast concrete structures with grouted sleeve (GS) connections has gained significant traction in the acceleration of bridge construction. The plastic hinge length (Lp) is a critical parameter for assessing the seismic performance and deformation capacity of such structural members. The previous study has proposed empirical equations for Lp in monolithic columns; however, a comprehensive understanding of the influential parameters on Lp in precast concrete columns with GS connections remains limited. This study presents a detailed parametric investigation to evaluate the effects of key design parameters on the plastic hinge length of a precast concrete columns with GS …

Designing Classifact: Towards A Transparent And Secure Platform For Stakeholder-In-The-Loop Data Annotation, Philippine Waisvisz

Communications of the IIMA

AI systems depend on human judgment, yet many annotation workflows are either designed for data-science specialists or managed through external commercial platforms. The first approach may demand more technical skills than relevant stakeholders possess. The second can require organizations to transfer data, expertise, and governance to an outside provider. Both can limit the involvement of people who understand what data means in its real-world context. Human-in-the-loop approaches introduce human judgment. Stakeholder-in-the-loop annotation focuses on selecting and organizing people whose contextual knowledge fits the AI application.

This paper presents Classifact, a transparent and secure platform for stakeholder-in-the-loop data annotation and validation. …

Comparative Analysis Of Takagi-Sugeno And Mamdani Fuzzy Inference Architectures With Anfis-Based Automated Rule Generation For Eeg-Based Cognitive State Monitoring, Amina Radončić, Mehrija Hasičić, Jasmin Kevrić

Communications of the IIMA

Fuzzy inference systems have demonstrated considerable promise for EEG-based cognitive state monitoring in neurodegenerative conditions. However, two design decisions significantly influence system performance and clinical applicability: the choice of inference architecture (Takagi-Sugeno vs Mamdani) and the method of rule and membership function generation (manual expert-driven vs data-driven automated). This paper presents a comparative analysis of both dimensions in the context of an EEG-based Alzheimer’s disease monitoring system operating on the ds004504 OpenNeuro dataset (88 subjects: 36 AD, 23 FTD, 29 HC). A Takagi-Sugeno system, implemented as a hybrid FSM-Fuzzy architecture, is compared against a Mamdani equivalent across four axes: inference …

Monitoring System In The Georeactor Area During The Underground Coal Gasification Process, Aleksandra Tokarz, Jacek Grabowski, Krzysztof Korczak

Journal of Sustainable Mining

Safety control of the underground coal gasification (UCG) process involves ensuring that the process runs smoothly, monitoring changes occurring on the surface and in the rock mass, and counteracting the negative environmental impact of the process. The article presents the application of a monitoring system implemented in Poland, both in pilot tests conducted in shallow coal seams at the Barbara Experimental Mine and in deep coal seams at the Wieczorek mine, where a full-scale gasification process was tested. The analysis of the monitoring results carried out during the gasification experiment in an operating mine allowed for the identification of key …

Harmonicthreads: A Formative Evaluation Of A Fabric-Based Digital Musical Instrument Toward Inclusive Music-Making, Ellie Nguyen, Franceli L. Cibrian

Engineering Faculty Articles and Research

Background:

Inclusive music-making requires instruments that support varied bodies, abilities, musical backgrounds, and forms of participation. Digital musical instruments provide diverse approaches to sound creation, and fabric-based interfaces offer an alternative interaction modality that may support participation for some users and contexts. Their tactile and deformable properties enable forms of interaction that differ from conventional rigid or screen-based controllers and may offer inclusive possibilities in particular settings.

Objective:

This paper presents HarmonicThreads as a formative interaction-design case of a fabric-based digital musical instrument. The prototype explores how tactile cues, fabric deformation, projected visual feedback, and assisted accompaniment can support low-barrier …

Critical Strategic Deterrence Questions For Today, Keith B. Payne

Space and Defense

r. Payne visited the U.S. Air Force Academy to offer keynote remarks at a national student congress, the 66th Academy Assembly, held during March 3-5,2026 and dedicated to the topic of the Global Chessboard: Strategic Deterrence in a New Era of Great Power Competition. Dr. Payne is co-founder of the National Institute for Public Policy, former Department Head at the Graduate School of Defense and Strategic Studies, Missouri State University, a former Deputy Assistant Secretary of Defense, and former Senior Advisor to the Office of the Secretary of Defense. He has authored or co-authored over 230 published articles and 50 …

Planetary Defense As The Ethico-Legal Gateway For International Space Security, Evie Kendal

Space and Defense

Following the news in late 2024 that there was a city-killer asteroid on a possible collision course with Earth, many members of the public were shocked to learn there was no reliable global plan for managing such asteroidal and cometary impact hazards. While calculations of Asteroid 2024 YR4’s trajectory were further refined to exclude the previously reported 2-3% chance of collision in 2032, this event highlighted a major security threat: the lack of a globally coordinated, appropriately resourced, and politically supported planetary defense strategy (Gibney, 2025). In so doing, it also provided an opportunity for security experts to consider the …

Space-Based Missile Defense With Early Interceptor Launch Strategies, William Priedhorsky, James Wells

Space and Defense

There is renewed interest in space-based boost-phase intercept (SBPI) for missile defense against ICBMs of near-peer adversaries. We discuss SBPI in the context of other missile defense approaches, and address one of its challenges, which is the expense of fielding a large enough constellation of interceptors in space to counter even a small number of ICBMs. We develop an early-launch approach that could substantively reduce the required density of interceptors. Because every second matters in boost-phase defense, early launch of interceptors can significantly increase the reach of each interceptor. Early launch would require interceptors that have highly throttleable motors. Our …

A Framework For Automated Quantity Extraction From .Ifc Models And Normalized Bid Comparison, Asmaa Mohamed Farouk

Theses and Dissertations

Accurate bid comparison remains a major challenge in construction tendering due to

differences in Bill of Quantities formats, item naming conventions, and pricing methods across

contractor submissions. These variations require time-consuming manual work and often lead to

subjective decisions. This research presents a computational framework that uses Building

Information Modeling through the .ifc file format, combined with text analysis techniques for

automated bid normalization.

The developed system uses a dual-component approach. Phase 1 extracts quantities from .ifc

model files using 3D geometric calculations, automated element classification. Phase 2 uses text

mining with a domain-specific dictionary of construction terms to interpret …

Synthesis Of Fe-Doped Porous Carbon Catalyst Derived From Coconut Shell Waste Using Ferric Nitrate Nonahydrate (Fe(No3)3.9h2o) As An Iron Precursor, Ilham Lestadi Putra, Sukarni Sukarni, Heru Suryanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Renewable energy from lignocellulosic biomass is a promising alternative to fossil fuels. Coconut shell (CS) waste is a favorable precursor for porous carbon due to its high carbon content, abundance, and non-food nature. However, conventional biochar often has limited surface area and catalytic active sites, hindering its effectiveness as a catalyst. While Fe-based modifications are promising, the use of ferric nitrate-assisted activation of coconut-shell-derived porous carbon remains underexplored. This research focused on developing an Fe-doped porous carbon catalyst from CS via ultrasound-assisted impregnation, followed by activation in a tube furnace. CS biochar was produced through pyrolysis at 550 °C and …

How Do Governments Combat Jihad Online?, Noah Cook

Honors College Theses

Since the September 11th, 2001 attacks, jihadist groups like ISIS, al-Qaeda, and al-Shabaab have used the internet as a tool for recruitment, radicalization, and propaganda dissemination. Since then, governments, non-governmental organizations, and private companies have developed strategies to combat jihadism on the internet. This paper examines how these actors have worked to mitigate the digital jihadist footprint and its effects by analyzing three main approaches to countering violent Islamist extremism on the internet: counter narrative initiatives, awareness-raising programs, and content removals. This paper finds that each of these methods has its own strengths and weaknesses. Counter narrative campaigns show the …

One Size Does Not Fit All: Revisitingworld Models And Neurosymbolic Ai, Amit P. Sheth, Madhur Thareja, Anushka Pawar, Niyati Rawal

Publications

World models are being built twice, from opposite ends, without a shared theory of how the two halves should meet. One lineage grounds the world model in perception: a self-supervised, latent-predictive encoder – exemplified by Joint Embedding Predictive Architectures (JEPA) – that learns the structure of sensory experi-ence. A second, older lineage grounds the world model in cognition: an explicit, inspectable structure of entities, rules, and constraints, ranging from knowledge graphs to formal logic to physical law. Neither lineage alone has produced a world model that is simultane-ously adaptive and auditable. We argue this is not solved by picking a …

In Situ Electrochemical Characterization Techniques For Active Hydrogen In Electrocatalytic Nitrate Reduction To Ammonia, Hong-Mei Li, Mei Yi, Zhao-Yu Jin, Ming-Hao Xie, Khalid M. Omer, Yong Guo, Pan-Pan Li

Journal of Electrochemistry

Electrocatalytic nitrate reduction to ammonia (NitRR) represents a sustainable pathway that integrates environmental remediation with the production of high-value ammonia. However, the activity and selectivity of this process are limited by the generation, consumption, and dynamic equilibrium of the key transient intermediate—active hydrogen (*H). Precise modulation of *H necessitates a comprehensive understanding of its behavior, which relies fundamentally on advanced in situ electrochemical characterization techniques. However, a systematic review dedicated to the rational selection and application of in situ electrochemical techniques for the specific characterization of *H in NitRR, with clear definitions of each technique's "detectable targets, quantitative accuracy, and …

Layer 3 Switching, Todd R. Zatorski

Small Satellite Conference

Poster presented at the 2026 Small Satellite Conference

Semi-Autonomous Reconnaissance Satellite: A Laboratory Demonstration Of End-To-End On-Board Mission Autonomy, Eran Shtoyerman, Raphael Cohen, Rafi Cohen, Oshri Fatkiev, Guy Zaidman, Gal Pinchas, Doron Shterman

Small Satellite Conference

Real-time satellite responsiveness to user requests from the field remains largely unavailable in current space systems. Such capabilities are typically restricted to low-altitude airborne platforms, primarily due to limited satellite communication bandwidth, intermittent ground contact, and the reliance on ground-based mission planning. Enabling true responsiveness requires a paradigm shift toward highly autonomous satellites, in which target selection, task execution, and mission planning are performed on board.

For example, a user may request a satellite to perform the following task in real-time: detect a ceiling tanker ship in a specified area, estimate its velocity from video data, and autonomously track the …

Zerodur®: Comprehensive Data Enables The Reliability Of Evidence-Based Design, Dustin Ruth, Florian Gollier, Jesse Bonfeld, Dustin Ruth, Janina Krieg, Thomas Westerhoff, Tony Hull, Jacqueline Caraballo

Small Satellite Conference

ZERODUR® is a glass-ceramic formulated for high-performance optics under imperfect temperature control. Crystallites in a glass matrix balance expansion: crystals shrink while residual glass expands, preserving geometry at fine scale.

This yields the lowest passive thermal response of any optical material-enabling high-contrast, high-resolution, low-scatter imaging and minimal transmission leakage for SmallSat telescopes.

Mechanisms And Implications Of The Novel Cast Model Of Coal Graphitization, Wang Shaoqing, Zhang Jingzhe, Zhang Xiaomei, Wang Xiaoshuai, Chen Hao, Wang Xiaoling, Li Wu, Tang Yuegang

Coal Geology & Exploration

Objective and Methods Coal graphitization is a multi-stage process with abrupt changes rather than linear evolution. So far, its inherent driving mechanisms have not yet been fully elucidated. Notably, twisted graphene was observed in the process of coal graphitization in 2025, providing a new opportunity to reveal the essence of this structural transformation. Results and Conclusions By combining previous research results, this study proposes a novel coal graphitization model that consists of condensation, alignment, stacking, and twisting (CAST). The four parts of the CAST model are organically integrated, collectively forming a continuous and dynamic evolutionary process. Most especially, no absolute …

Dynamic-To-Static Elastic Parameter Conversion Models For Coals Under Temperature-Pressure Coupling: A Case Study Of The No. 8 Coal Seam In The Daning-Jixian Block, Zhang Wei, Wu Peng, Liu Conghui, Zhang Sidun, Sun Xuedong, Yang Haixing, Ma Zhuang, Shi Rui, Shen Jian

Coal Geology & Exploration

Objective Existing dynamic-to-static elastic parameter conversion models for coals fail to fully account for the actual in situ pressure and temperature conditions of deep reservoirs. This leads to significant deviations in directly evaluating the mechanical properties of reservoirs using log-derived dynamic parameters. To address this challenge, this study investigated dynamic-to-static elastic parameter conversion under the in situ stress and geotemperature conditions of strata. Accordingly, high-precision parameter conversion models were established. Methods This study examined coal samples from the No. 8 coal seam at a burial depth of approximately 1200 m in the Daning-Jixian block along the eastern margin of the …

Key Technologies And Engineering Practices For Green Drainage Of The Jurassic Burnt Rock-Hosted Water In The Shenfu Mining Area, Ji Zhongkui, Mou Lin, Wang Hai, Zhu Kaipeng, Zhao Kaixing, Chen Pan, Xue Xiaoyuan, Han Qiang, He Bo, Wang Fuming

Coal Geology & Exploration

Objective In the northern part of Shaanxi Province, coal mining has led to a pronounced contradiction between coal mining and water conservation, along with a serious threat to China’s ecological redline. These challenges necessitate transforming the mine water drainage pattern in coal mines. Green mine water drainage represents a key approach to achieving coordinated coal-water production in areas containing burnt rocks. Methods Focusing on the conservation-oriented utilization of the Jurassic burnt rock-hosted water in a coal mine within the Shenfu mining area, this study explored a solution to coordinated coal-water production in areas affected by burnt rock-hosted water from the …

Magnetic Balancing For Microvibration Reduction In Passive Magnetic Bearings For Smallsat Reaction Wheels, Deckers Niel, Baekeland Mante, Cuypers Cedric, Seiler Rene, Vandepitte Dirk, Delabie Tjorven

Small Satellite Conference

Reduction and mitigation of microvibrations constitutes a crucial field of interest in the research of spacecraft reaction wheels. This applies all the more so in small satellites, where even minimal sources of vibrations lead to imprecision of onboard instruments. To address this, magnetic bearings offer contactless support, and thus prevent several sources of microvibrations that exist in classical ball bearings, for instance the mechanical imperfections in rolling elements. The inherently low stiffness of magnetic bearings also significantly reduces the transmitted forces in reaction wheels. Another advantage of contactless support is its potential longer lifetime because of the absence …

Recovery Of Grus-1e From Magnetic Torquer Loss Using Data-Driven Open-Loop Attitude Steering, Nader Ganaba, Takanori Iwata, Minoru Kurata

Small Satellite Conference

In typical low Earth orbit (LEO) operations, the inability to remove excess angular momentum often leads to the decommissioning of a satellite. This paper presents the on-orbit recovery of GRUS-1E, a hundred kg class Earth observation satellite in Axelspace Corporation’s GRUS-1 constellation. The recovery followed the permanent loss of magnetic torquer commanding capability, which in turn disabled the satellite’s nominal reaction wheel momentum unloading. In addition, the satellite experienced persistent disturbance torques that significantly exceeded the combined contributions predicted by standard models, including gravity gradient, solar radiation pressure, aerodynamic drag, and the estimated residual magnetic dipole moment. The magnitude of …