Mechanical Engineering Commons^™

Apply Cluster Analysis To Improve Interpretation Of Ert Images, Yin-Chun Hung, Yu-Xiang Zhao

Journal of Marine Science and Technology–Taiwan

The completeness and accuracy of collecting and investigating geotechnical and marine engineering geological conditions are key to the success or failure of engineering development. Traditional marine engineering and geotechnical surveys often require the assistance of geophysical methods to fully present the geological conditions. Electrical Resistivity Tomography (ERT) is an advanced geophysical method that produces accurate cross-sections of underground resistivity. Although 2D ERT has been widely used in geotechnical engineering and marine engineering, many uncertainties remain hidden behind the vivid and colorful resistivity profiles. To apply 2D ERT profiles effectively in geotechnical and marine geological surveys and monitoring, it is essential …

Geo-Chemical Fractionations Of Phosphorus In Sediments Of Thuy Trieu Lagoon And Cam Ranh Bay, Vietnam, Phu H. Le, Ngoc H. Pham, Dung T. Le, Tuan Linh T. Vo, Binh V. Tran, The V. Ho

Journal of Marine Science and Technology–Taiwan

The geochemical fractions of phosphorus (P) and its bioavailability in sediments of Thuy Trieu Lagoon and Cam Ranh Bay were investigated. Twenty-four surface sediment samples were collected in the dry season (Jun 2024) and the rainy season (Oct 2024). A sequential extraction procedure was applied to identify the phosphorus (P) fractions in sediments, including Exchangeable P (Ex-P), iron-bound P (Fe-P), aluminum-bound P (Al-P), calcium-bound P (Ca-P), and residual P (Res-P). Total P (TP) ranged from 214.9 to 2365.2 µg.g^-1, and the Ca-P fraction was the dominant chemical form in sediments. Based on the results of Pearson correlation and …

Beyond Basic Needs : Exploring The Antecedents And Outcomes Of Seafarers’ Well-Being, Chian Liou, Cheng Kuo Sung, Kimberly Hsiu-Chin Lee, Jiunn Liang Guo

Journal of Marine Science and Technology–Taiwan

Given the importance of seafarers’ mental health and the limited literature on this topic, this study aims to explore the causes and consequences of seafarers’ well-being. A questionnaire survey was conducted, and the data were analyzed using structural equation modeling and hierarchical regression analysis. Consistent with the predictions of the happy and productive worker thesis, this study found that the more satisfied the seafarers are with the shipping company’s seafarer policy, the higher their well-being tends to be, leading to a more positive work attitude. Interestingly, the study found that a company effect is significantly present in this correlation; that …

Empowering Shipping Management Competence With Artificial Intelligence: A Strategic Approach To External Environmental Volatility, Yu-Kai Huang, Cheng-Hsien Hsieh, Chi-Chang Lin, Yu-Tzu Chang, Yu-Chao Cheng

Journal of Marine Science and Technology–Taiwan

The shipping industry is undergoing significant transformation with advancements in artificial intelligence (AI), yet challenges remain in effectively adopting AI technologies. This study addresses the key concerns influencing AI adoption in shipping management. Using the Analytic Hierarchy Process (AHP) integrated with the PEST model, an evaluation framework was developed to assess AI applications in shipping companies. Based on expert input collected through the Delphi method, four constructs and twelve criteria were identified, with the 'Technological' dimension being the most critical. 'Robustness,' 'Costs,' and 'Data quality' emerged as the top factors affecting AI implementation. The framework offers practical insights for shipping …

Comparative Evaluation Of Deep Learning Models For Predicting Skipjack Tuna (Katsuwonus Pelamis) Catch Based On Climatic Factors, Peng Ding, Hui Xu, Xin Zhuang, Yan-Lun Wu, Fengyuan Shen, Yujie Xiao, Jiensi Zhulidezi, Wei-Yu Lee

Journal of Marine Science and Technology–Taiwan

To investigate the impact of climatic factors on skipjack tuna catch, this study collected and analyzed annual global skipjack tuna catch data spanning from 1960 to 2021, along with corresponding monthly data for the key indicator of El Nino events (Niño1+2, Niño3, Niño4, and Niño3.4), the Southern Oscillation Index (SOI), the North Atlantic Oscillation (NAO), the Pacific Decadal Oscillation (PDO), the North Pacific Index (NPI), and the global sea-air temperature anomaly index (dT). The optimal lag years of climatic factors were identified by selecting the maximum absolute cross- correlation coefficients. Subsequently, the predictive performance of LSTM, BiLSTM, and CNN-BiLSTM models …

Effects Of Train-Ship Direct Transshipment On Container Terminal Operational Efficiency And Energy Consumption: From A Scheduling Perspective, Yiying Du, Yaozong Wang, Zhongzhen Yang

Journal of Marine Science and Technology–Taiwan

On-dock rail integration positions terminals as critical hubs for rail-sea transshipment, which necessitates efficient scheduling for rapid container transfers. Given the strict schedules and batch arrival of railway containers, in this study, we propose a train-ship direct transshipment (TSDT) mode to eliminate nonproductive yard rehandling. To comprehensively evaluate the impact of the proposed mode on terminal handling operations, we developed an operational scheduling model for the entire process of the simultaneous loading of yard containers and railway-handling area (RHA) containers. The model comprises two stages. Stage 1 models the pre-reshuffling operations in the yard before loading, and Stage 2 implements …

Key Success Factors In Using The Lifting Method To Construct A Steel Bridge Pylon, Ming-Chao Su, Hui-Ping Tserng

Journal of Marine Science and Technology–Taiwan

Constructing the inclined steel pylon of cable-stayed bridges is challenging because of the pylon’s height, spatial limitations, and safety concerns. To address these challenges, this study developed a modular lifting method that can enhance the efficiency and precision of pylon construction. The proposed method involves using rotation jigs to temporarily assemble the pylon, horizontal positioning on temporary supports, and synchronized lifting through computer-controlled hydraulic systems. Field implementation on a large-span bridge project revealed that compared with the traditional method, the proposed method resulted in higher welding quality, lower risks associated with great-height operations, and a shorter on-site assembly time. The …

Deep Learning-Based Model For Automated Prediction Of Coastal Changes: A Robust Approach To Environmental Forecasting, Tsair-Fwu Lee, Chu-Ho Chang, Chin-Shiuh Shieh, Chih-Hsien Wu, Jen-Chung Shao, Chien-Liang Chiu

Journal of Marine Science and Technology–Taiwan

The coastline stands as a critical domain encompassing industry and the environment. The escalating global warming, leading to elevated sea levels and intensified wave-current interactions, has given rise to substantial coastal erosion. This predicament, in conjunction with excessive human development and Taiwan's coastal areas' extreme climatic impact, accentuates the perceptibility of coastal beach alterations. As a result, coastal erosion has emerged as a pressing issue necessitating resolution. Traditional methodologies for assessing coastline changes have conventionally relied on manual measurements. However, owing to the fluctuating distance of coastlines, influenced by tidal patterns, extended measurement processes over several months are susceptible to …

Hydrographic Influences On Seasonal Variations In Zooplankton Communities Of Taiwan Bank (Southern Taiwan Strait), Bor-Shyr Chen, Frank Paolo Jay B. Albarico, Mark Ariel D. Malto, Aiza D. Gabriel, Chiu-Wen Chen, Cheng-Di Dong

Journal of Marine Science and Technology–Taiwan

Understanding the factors that control ocean productivity is crucial in fisheries management. Taiwan Bank, located between the Taiwan Strait and the South China Sea, is a highly productive ecosystem due to upwelling events. The total zooplankton community (holozooplankton and merozooplankton), diversity, seasonal changes, and environmental drivers remain unexplored despite its productivity. This study evaluates the seasonal and vertical environmental dynamics in the Taiwan Bank and their impacts on the zooplankton community structure. We collected zooplankton and basic water parameters in March, July, and September 2017 at 5, 25, and 50 meters. We recorded significant seasonal changes in zooplankton composition and …

Model Performance For Predicting Trends And Analyzing The Impacts Of Sea Surface Temperature Changes In The Gulf Of Thailand, Tanatpong Udomchaipitak, Nathaphon Boonnam

Journal of Marine Science and Technology–Taiwan

This study focuses on assessing and improving the predictive performance of sea surface temperature (SST) in the Gulf of Thailand under unique environmental challenges. Data from the Hybrid Coordinate Ocean Model (HYCOM) were utilized, covering the period from July 1994 to June 2024 at depths ranging from 0 to 30 meters. After cleaning the data using the Interquartile Range (IQR) method, the processed dataset was tested using four models: Recurrent Neural Network (RNN) architectures, including Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU), as well as Convolutional Neural Networks (CNNs). Model performance was enhanced by tuning the parameters over …

A Study Exploring The Use Of Artificial Ligaments To Enhance The Human-Robot Interface Via Force Distribution Manipulation In Biomimetic Cuff Systems, Adifet Cejovic

Dissertations and Theses

Comfort is among the main priorities when designing a wearable assistive device that needs to be used for long sessions. There is a growing need for wearable systems that provide aid to patients with an injured knee. In addition, there has been an effort to incorporate cable-driven designs rather than rigid attachments. This change in design decreases the overall weight of the system and can allow the cable to adapt to a user’s change in gait patterns. This thesis investigates a cuff system centered around the knee and the design of a testing rig. This system incorporates elements from pre-existing …

An Environmental And Durability Study Of Bonded Structural Patch Repairs With Finite Element And Machine Learning Enabled Predictions, Yesim Kokner

Dissertations and Theses

Aircraft and vehicles experience substantial structural and aerodynamic stresses over their operational lifetimes. These stresses can cause damage or structural weakening, especially in aging military and civilian aircraft and vehicles. Depending on the severity of the damage, three options are available to alleviate the damage in these structures or parts: complete replacement of the aircraft or vehicle, replacement of the damaged part, or temporary repair of the damage.

The goal of this study is to evaluate damaged specimens repaired with an adhesively bonded patch subjected to quasi-static and fatigue loads under various environmental conditions. The patch repair technique is widely …

Development Of An Quadcopter Unmanned Aerial Vehicle For Atmospheric Remote Sensing, Omar J. Addasi

Dissertations and Theses

This paper explores the development of a quadcopter unmanned aerial vehicle (UAV, a.k.a. drone) for atmospheric remote sensing of temperature, pressure, humidity, and PM2.5 particulate matter quantities. A 3-D printed drone body is designed and flight tuning is performed. An optimal length for an upward extending mast for the drone body is determined. Low cost, lightweight sensors are compared against higher precision sensors in both static and dynamic conditions. In addition, an initial investigation into the design of a pressure sensor based anemometer is performed.

Design And Lab Implementation Of An Air Source Transcritical Co2 Heat Pump, Geoffrey Turbeville

Dissertations and Theses

A laboratory-scale air-source transcritical CO2 heat pump (TCHP) was developed to evaluate the performance of low-global-warming-potential (GWP) refrigerants for cold climate applications. A custom climate chamber was also constructed to simulate winter weather conditions typical of the northeastern United States. Both the TCHP and the chamber were fully instrumented to collect temperature, pressure, and mass flow data, which were used to calculate the co- efficient of performance (COP) in accordance with ASHRAE standard refrigerant enthalpy methods. Prior to testing the CO2 system, the experimental setup was benchmarked using a commercially available R410A heat pump manufactured by LG.

The climate chamber …

Cfd Modeling And Simulation Of Natural Circulation In Helium- Cooled Very High Temperature Reactors, Mohammad Sakib U. Abrar

Dissertations and Theses

This thesis investigates the thermal-hydraulic behavior of natural circulation in helium-cooled Very High Temperature Reactor (VHTR) systems, focusing on the performance and validation of passive safety features under Pressurized or Depressurized Loss of Forced Cooling (P-LOFC or D-LOFC) events. An experimental facility inspired by the General Atomics 350 MWt Modular High Temperature Gas-Cooled Reactor (MHTGR) was developed at The City College of New York. The setup consists of a plenum-to-plenum flow loop with four riser and four downcomer tubes, each equipped with heating coils, thermocouples, and pressure sensors. Natural circulation is driven by density gradients induced by asymmetric heating of …

Multi-Material Adhesive Bonded Joints Under Static And Dynamic Loading, Gizem Derya Demir

Dissertations and Theses

Adhesively bonded joints present significant potential for reducing structural weight and enhancing performance in modern and future engineering structures. By enabling the elimination or reduction of traditional mechanical fasteners and facilitating the integration of dissimilar materials, adhesives can contribute to more efficient, lightweight designs. However, to fully leverage these benefits—especially in high-performance applications—adhesive materials must exhibit robust behavior under both static and dynamic loading conditions, such as ballistic impact. Despite their promise, the failure mechanisms of adhesives under such high-strain-rate scenarios remain insufficiently understood.

This dissertation investigates the performance of adhesively bonded multi-material joints subjected to static loading and ballistic …

Experimental And Analytical Investigation Of Particle Dynamics In Newtonian And Non-Newtonian Fluids In A Taylor-Couette Cell, Andres F. Velez Mendoza

Dissertations and Theses

This doctoral dissertation investigates heavy particle sedimentation in Newtonian and non-Newtonian fluids, aiming to understand their behavior in Drilling Fluid (DF) systems used in oil and gas industry, where such phenomenon can lead to operational issues such as lost circulation, well control problems, and even blowouts. To simulate DF dynamics under operational conditions, this study utilizes a Taylor-Couette (TC) cell, which consists of a rotating inner cylinder and a stationary outer cylinder separated by a 9.0 mm annular gap. The TC cell allows for the investigation of the sedimentation behavior of spherical particles within both Newtonian fluids (deionized water and …

Evaluating The Effectiveness Of Stay-In-Place Forms To Improve The Tosional Stability Of Box Beam Bridges During Erection, Karl E. Barth, Michael W. Seek, Gregory K. Michaelson, Dimitra Pyrialakou, Brook T. Woldegabriel

Engineering Technology Faculty Publications

Cold-formed tub girders provide an effective steel solution for short-span bridges. The girders are often delivered with an open top with stay-in-place forms installed on site. Walkways may be installed to the side of the girder that can induce significant torsion rotations in the open cross section. Full scale tests on girder specimens have shown that installing one or two panels of stay in place forms at the ends of the girder can significantly reduce the torsion rotation of the girder by providing warping resistance. Cantilever tests on the stay in place forms are performed to investigate the influence of …

Characterization Of The Solid-State Bonding For Simulated Charge And Seam Welds In The Porthole Die Extrusion Process, Randall L. Bowers

Theses and Dissertations--Chemical and Materials Engineering

The isothermal (ISO-T) compression configuration is ideal for utilizing as a material input of flow stress at temperature and strain rate in models of the porthole die extrusion process due to the isothermal nature of the test. Micro-tensile testing was conducted to validate the solid-state welding integrity of the ISO-T samples at various temperatures and strain rates. Results of the mechanical testing were correlated with fractography and microstructural evaluations of the welds to confirm bonding behavior. Both clean interface conditions and oxidation and lubrication layers were evaluated to simulate the difference of seam and charge welds in the process. Results …

Atomistic Study Of Selenium Doping Effects On The Mechanical Properties Of Zinc-Blende And Wurtzite Cdte Nanowires, Sungwook Leo Hong, Nadeem Azad, Saifuddin Zafar, Abrar Faiyad, Hyung Sub Sim

Mechanical Engineering Faculty Works

CdSexTe1–x semiconductor materials, having potential to be used to design dependable and reproducible nanowire devices, require an extensive study of their mechanical behaviors. The uniaxial tensile deformation mechanism of CdSexTe1–x nanowires (NWs) with different Se dopant concentration are yet to be explored. By integrating theoretical analysis with computational simulation, this research demonstrated that Se doping in CdTe NWs influences the mechanical response and failure modes. Ultimate tensile strength (UTS) and elastic modulus (EM) were studied for both zinc-blende (ZB) and wurtzite (WZ) structures with different crystal orientations. The findings revealed that these mechanical properties increase linearly with increasing Se concentration …

The Role Of Artificial Intelligence In Boosting Cybersecurity And Trusted Embedded Systems Performance: A Systematic Review On Current And Future Trends, Xiangyi Cheng, Ahmed Oun, Kaden Wince

Mechanical Engineering Faculty Works

As technology becomes increasingly interconnected, ensuring the security of cyber and embedded systems is critical due to escalating vulnerabilities and sophisticated cyber threats. Researchers are exploring artificial intelligence (AI) to improve security mechanisms, yet there is a lack of a comprehensive technical, AI-focused analysis detailing the integration of AI into existing security hardware and frameworks. To address this gap, this article systematically reviews 63 articles on AI in cybersecurity and trusted embedded systems. The reviewed articles are categorized into four application domains: 1) Intrusion Detection and Prevention (IDPS), 2) Malware Detection, 3) Industrial Control and Cyber-Physical Systems (CPS) and 4) …

Computational Analysis And Design Of High-Entropy Nanoparticles: Integrating Atomistic Simulations With Scientific Pedagogy In Materials Research, Sungwook Leo Hong, Priyanshu Luhar, Ricardo Ramirez, Jiwon Lexi Hwang

Mechanical Engineering Faculty Works

This study leverages reactive molecular dynamics simulations to enhance undergraduate education and research in materials science. Focusing on the oxidation processes of a variety of energetic metal nanoparticles, including Al, Cu, Mg, and Ti, two undergraduate students led the scientific inquiry. They conducted literature reviews, ran simulations, validated assumptions, and analyzed results, deepening their understanding of material behaviors and strengthening their STEM identity. Through these hands-on experiences, the students successfully investigated the energetic properties of these nanoparticles, demonstrating the effectiveness of this approach in promoting inquiry-based learning. This work underscores the transformative potential of computational simulations in advancing computational materials …

Influence Of Alloy Composition On The Process Robustness Of Steels Consolidated Via Laser-Directed Energy Deposition, Jonathan Kelley

Masters Theses

"To ensure consistent quality of additively manufactured parts, it is advantageous to identify alloys which can meet performance criteria while being robust to process variations. Toward this end, this work investigated the effect of alloy composition on the robustness of steels consolidated via laser-directed energy deposition (L-DED). Ultra-high-strength low-alloy steel (UHSLA) and pure iron powders were mixed in-situ to produce 10 compositions containing 10-100% UHSLA by mass. JMatPro material simulations roughly predicted phases and mechanical properties. Two sets of experiments were used to evaluate the sensitivity of as-built hardness (all 10 compositions) and tensile properties (5 select compositions) to process …

Development And Prototyping Of A Modular Quadruped Towards Testing Standardization For Legged Robot Stability, Michael Conner Larsen

Graduate Research Theses & Dissertations

Legged robots are well-suited for navigating uneven and unmapped terrain, making them valuable in various robotics applications. Maintaining balance and stability in such environments relies on a combination of sensors, control strategies, and mechanical design. However, selecting the most effective sensing and control method for a given use case remains challenging. Previous studies have explored various approaches, integrating combinations of joint angle measurement, inertial measurement units (IMUs), torque-based control, leg force measurement, image processing, and machine learning, paired with numerous controller designs, which can contribute to stability. However, direct comparisons of these methods are often limited by the need for …

Piv Visualization Of A Sinusoidal Ehd Confinement Flow Induced By Variation In Ion Density For Electrostatic Particle Agglomeration, Md Eyasin Hossain

Graduate Research Theses & Dissertations

Long-term exposure to PM2.5, which is responsible for four million cardiovascular-related deaths worldwide, is a major concern as people spend 90% of their time indoors. Fabric filters have been commonly utilized for particle pollution control in indoor settings. However, the maintenance cost of fabric filters is relatively high, as particle accumulation on filters can lead to higher pressure drops (45 ∼ 300 Pa) and energy consumption, as well as the growth of biological organisms and the generation of airborne pathogens. An electrostatic precipitator (ESP) is filterless and widely used in the electric power industry for collecting coal fly ash. ESPs …

Md Simulation Of Femtosecond Laser-Controlled Melting Of Multiple Core-Shell Nanoparticle Systems, Shivansh Patel

Graduate Research Theses & Dissertations

This thesis presents a molecular dynamics (MD) simulation study of femtosecond laser-induced melting and heat transfer in multiple Cu–Al core–shell nanoparticle systems. The research builds upon previous single-particle studies and extends the investigation to multiple interacting nanoparticles to better understand nanoscale thermal transport and melting behavior under ultrafast laser irradiation. Understanding this process is essential for improving laser-based additive manufacturing and sintering of metal matrix nanocomposites (MMNCs), where precise control of heat flow and particle bonding determines the final material quality. The simulations were performed using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) integrated with the Modified Two-Temperature Model (MTTM). …

Material And Mechanical Characterization Of Sla 3d Printed Graphene Nanoplatelet-Based Nanocomposites Fabricated Within A Magnetic Field, Soka Suliman

Graduate Research Theses & Dissertations

The process of utilizing a static magnetic field to fabricate a nanomaterial-based composite via a stereolithography (SLA) 3D printing process is still a relatively new approach within the field of additive manufacturing. By using this magnetic field during the 3D printing process, both material and mechanical properties can be oriented and axially varied for enhanced characteristics. In this investigation, between 0% to 2% volume fractions of high aspect ratio, graphene nanoplatelets (GNP) are suspended within UV-curable resin during a SLA 3D printing process with a static magnetic field applied. The objective of this investigation is to determine the effect of …

Human Swarm Interaction Using Non-Verbal Communication, Arunim Bhattacharya

Graduate Research Theses & Dissertations

This research presents experimentally validated strategies for human-swarm robotic interaction through nonverbal communication. Applications of this work are in large-scale coverage problems that include search and rescue operations and environmental monitoring missions. The non-verbal interaction becomes critical in situations where wireless communication methods may be limited by bandwidth constraints, privacy concerns, or environmental clutter. The research objective of this dissertation is to design and evaluate methods of nonverbal communication between a human teleoperator and robotic swarms towards a bidirectional human-swarm interaction framework. Towards this, we first establish a reliable measure of real-time cognitive load that can serve to close the …

Laser Based Metal 3d Printer, Inura Goonawardena

All Graduate Theses, Dissertations, and Other Capstone Projects

The technology and applications of additive manufacturing (AM) have advanced significantly in recent years. Research from hobbyist to industrial scale has evolved and has seen advancements in materials that can be utilized for industrial manufacturing. The Institute for Machine Tools and Industrial Management at the Technical University of Munich (TUM) developed the reAM250, an open-source research platform for Powder Bed Fusion with a Laser (LPBF). It was made available to facilitate study into component-level innovation, control techniques, and process monitoring without the budgetary and intellectual property constraints of commercial machines. This paper delves into the concept and production of the …

Design And Optimization Of The Injection Molding Process Of Glass Fiber Reinforced Polymeric Car Fender Using Computational Simulation, Synthia Ferdouse

Electronic Theses and Dissertations

The increasing demand for lightweight and energy-efficient materials in the automotive industry has accelerated the adoption of fiber-reinforced polymer composites. This research presents the design and optimization of the injection molding process for glass fiber-reinforced polymer (GFRP) car fenders using computational simulation. The effects of various gate types and locations on key process parameters, including fiber orientation, volumetric shrinkage, shear rate, and fill time, were investigated using Finite Element Analysis (FEA), Autodesk Moldflow Insight 2024, and MATLAB-based Multi-Criteria Decision-Making (MCMD) techniques. Simulations were conducted across multiple configurations involving three, four, and five gates, with several variations in location. Among all, …