Containerization Of Seafarers In The International Shipping Industry: Contemporary Seamanship, Maritime Social Infrastructures, And Mobility Politics Of Global Logistics,
2024
CUNY Graduate Center
Containerization Of Seafarers In The International Shipping Industry: Contemporary Seamanship, Maritime Social Infrastructures, And Mobility Politics Of Global Logistics, Liang Wu
Dissertations, Theses, and Capstone Projects
This dissertation discusses the mobility politics of container shipping and argues that technological development, political-economic order, and social infrastructure co-produce one another. Containerization, the use of standardized containers to carry cargo across modes of transportation that is said to have revolutionized and globalized international trade since the late 1950s, has served to expand and extend the power of international coalitions of states and corporations to control the movements of commodities (shipments) and labor (seafarers). The advent and development of containerization was driven by a sociotechnical imaginary and international social contract of seamless shipping and cargo flows. In practice, this liberal, …
Two-Phase Flow Simulations With Plic-Vof Method And Dynamic Mesh Refinement,
2024
University of Texas at Arlington
Two-Phase Flow Simulations With Plic-Vof Method And Dynamic Mesh Refinement, Vimalan Adaikalanathan
Mechanical and Aerospace Engineering Dissertations - Archive
Two-phase flows are critical in a variety of engineering applications that span multiple length scales. These applications encompass macroscopic phenomena, such as dam breakage and wave-structure interactions, as well as microscopic events, including droplet impacts and boiling, and mixed-scale issues like spray dynamics. Accurate representation of evolving interfaces is essential for numerical simulations of these problems, and the Volume of Fluid (VOF) method combined with the Piecewise Linear Interface Calculation (PLIC) approach is employed to fulfill this requirement. To tackle the computational challenges associated with high-resolution meshes in deforming two-phase flows, Adaptive Mesh Refinement (AMR) is utilized to enhance mesh …
Nonlinear Hydrodynamic Modeling And Control Of Wave Energy Converters,
2024
Michigan Technological University
Nonlinear Hydrodynamic Modeling And Control Of Wave Energy Converters, Tania Demonte Gonzalez
Dissertations, Master's Theses and Master's Reports
The growing urgency to transition towards carbon-neutral energy sources has sparked significant interest in diversifying energy portfolios by incorporating renewable energies, including the untapped potential of wave energy. This dissertation sets its objectives in advancing wave energy converter (WEC) technologies by focusing on developing and validating a nonlinear modeling technique and designing control strategies to maximize energy extraction and enhance WEC efficiency. At the heart of this research is the derivation and validation of an algebraic nonlinear Froude-Krylov forces model. Building on this foundational model, a robust nonlinear sliding mode controller and a nonlinear model predictive controller are designed to …
Design, Testing And Neural Network Modeling Of A Low-Friction Wave Energy Converter Testbed,
2024
Michigan Technological University
Design, Testing And Neural Network Modeling Of A Low-Friction Wave Energy Converter Testbed, Vasu Bhardwaj
Dissertations, Master's Theses and Master's Reports
Point absorber wave energy converters (WECs) transform water wave kinetic energy into other useful forms, typically electrical. While it’s possible to extract energy from passive WECs, more energy can be captured using active control where its power take-off (PTO) acts as both a generator and an actuator. Control strategies usually require accurate models often obtained during model-scale testing. Unfortunately, friction can dominate the dynamic response in small WEC models. A frictionless point absorber WEC testbed is described in this report which allows the researcher to focus on fundamental hydrodynamic behavior instead of friction. It uses air bearings for vertical motion …
Wave Energy Converter Wave Force Prediction Using A Neural Network,
2024
Michigan Technological University
Wave Energy Converter Wave Force Prediction Using A Neural Network, Morgan Kline
Dissertations, Master's Theses and Master's Reports
Due to the unpredictable nature of large bodies of water, wave energy can be a difficult renewable resource to rely on. One way to make Wave Energy Converters (WECs) more efficient is to apply a control strategy. In many control solutions, it is assumed that the wave excitation force is known into the future. In many instances, especially with complex waveforms, this is simply not the case. Simulation studies have shown the promise of wave force prediction using neural networks. This study demonstrates this experimentally and aims to characterize the important factors when designing such a network. Several wave elevation …
A Strategic Framework For Estimating International Container Flows: An Empirical Study,
2024
Department of Industrial Engineering and Engineering Management National Tsing Hua University
A Strategic Framework For Estimating International Container Flows: An Empirical Study, Dung-Ying Lin, Hsin-Chun Huang, Steven Travis Waller, Xiang Zhang
Journal of Marine Science and Technology–Taiwan
Maritime transportation is a highly complex transportation system that plays a pivotal role in international trade. Its low-cost and high-volume advantages have enabled it to cover most of the world’s cargo transportation. However, with the trend of global trade volume increasing almost every year and the recent congestion of ports due to the COVID-19 pandemic, the chaos in global supply chains not only increases operating costs for shippers but also makes it difficult for countries that rely heavily on port trade to plan for their ports’ future. To develop a strategic analytic tool to estimate container flow in liner shipping, …
Exploring Market Segmentation For Autonomous Ferries,
2024
Department of Shipping and Transportation Management, National Taiwan Ocean University
Exploring Market Segmentation For Autonomous Ferries, Ashari Fitra Rachmannullah, Taih Cherng Lirn, Kuo Chung Shang
Journal of Marine Science and Technology–Taiwan
This study aims to investigate the determinants that underlie psychographic segmentation in the domain of autonomous ferries (AFs) by using the theory of planned behaviour (TPB) as a guiding theoretical construct. The paper focuses on Indonesian individuals who had previously utilised conventional ferry services. TPB was applied as a catalyst to identify possible market segmentation among potential AF passengers. In this study, cluster analysis is used to differentiate passengers by their perception of using AFs. The results identified three market segments through cluster analysis based on passengers’ perceptions of using AFs: Resource-Limited, Resource-Capable, and Value-Optimistic. Among these segments, the Resource-Capable …
Adaptive Prediction Horizon Energy-Saving Collision-Free Mpc Of Ships Based On Ship-Shore Cooperation,
2024
College of Navigation, Jimei University, Xiamen 361021,Fujian,China)
Adaptive Prediction Horizon Energy-Saving Collision-Free Mpc Of Ships Based On Ship-Shore Cooperation, Han Xue, Enjie Yang
Journal of Marine Science and Technology–Taiwan
ABSTRACT:In order to perform the close association between ship maneuvering control and energy consumption through the control strategy, this paper designs an adaptive prediction horizon based energy-saving robust nonlinear model predictive control (APHERNMPC) for underactuated ships to deal with the actual control and state constraints during berthing based on ship-shore cooperation. An improved Emperor Penguin Optimizer (EPO) method is proposed for collision avoidance decision. To solve the problems of falling into local optimum and reducing the convergence speed, the traditional EPO is improved based on Sobol sequence in order to enhance the diversity and ergodicity of the population. The multi-ship …
Research And Design A Lifeboat Virtual Reality Simulation System For Maritime Safety Training In Vietnam,
2024
Faculty of Navigation – Vietnam Maritime University, Haiphong, Vietnam
Research And Design A Lifeboat Virtual Reality Simulation System For Maritime Safety Training In Vietnam, Nguyen Dinh Thach, Nguyen Van Hung
Journal of Marine Science and Technology–Taiwan
Ensuring maritime safety and security is crucial for all nations. Training trainees and operational officers in this field aims to enhance their professional skills and ability to manage and resolve incidents at sea. This article outlines the development of a lifeboat simulation system that integrates Virtual Reality (VR) technology in accordance with international maritime regulations. It describes the creation of an algorithm designed to optimize data transmission between simulation systems using the ant colony optimization technique in conjunction with intelligent control algorithms on Unity 3D software for human interaction. In particular, the system combines training with a maritime simulation framework …
Fretting Corrosion Wear Of Titanium-Based Alloy (Ti-6al-4v) In 0.9 Wt.% Nacl Solution,
2024
Energy College, Quanzhou Vocational and Technical University, China.
Fretting Corrosion Wear Of Titanium-Based Alloy (Ti-6al-4v) In 0.9 Wt.% Nacl Solution, Chen-En Lu, Wen-Ken Li, Hung-Hua Sheu, Jeou-Long Lee, Hung-Bin Lee
Journal of Marine Science and Technology–Taiwan
In this study, a high precision fretting tribo-corrosion tester used to analyze the wear and corrosion behavior of Ti alloys in a fretting motion condition. The tester, operated in a ball-on-plate mode, was employed in the fretting corrosion study of metallic bio-materials (Ti and Ti-6Al-4V) under different loads (0 and 10 N), electrolytes (0.9 wt% NaCl and SBF) and fixed displacement frequency (1 Hz). Using profilometer, optical microscope in the experimental analysis and three-body mechanism in the theoretical analysis, the fretting corrosion performances of these bio-medical metals, such as velocity accommodation characteristics, friction, wear, and scratch profile were examined in …
A New-Type Deep Learning Model Based On Shapley Regulation For Containerized Freight Index Prediction,
2024
Department of Shipping and Transportation Management, National Taiwan Ocean University, Keelung 202301, Taiwan
A New-Type Deep Learning Model Based On Shapley Regulation For Containerized Freight Index Prediction, Yen-Chang Shih, Ming-Shue Lin, Taih-Cherng Lirn, Jih-Gau Juang
Journal of Marine Science and Technology–Taiwan
In this study, we have crafted an innovative methodology that represents a groundbreaking synthesis of deep learning techniques with cooperative game theory. In this study, we use the accuracy of data prediction by different LSTM models as a measurement index and assign different LSTM models corresponding weights through the Shapley value calculation method to construct a more accurate predictive analysis model. We use this improved Shapley regulation model to calibrate a long short-term memory (LSTM) neural network by using historical freight data to predict the China Container Freight Index (CCFI), the leading export container freight index commonly used in China. …
Applicability Of Reducing Valve Timing Overlap For Diesel Engines Under High Exhaust Back Pressure,
2024
Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, Taiwan, ROC
Applicability Of Reducing Valve Timing Overlap For Diesel Engines Under High Exhaust Back Pressure, Chien-Cheng Chen, Yuan-Liang Jeng, Shun-Chang Yen
Journal of Marine Science and Technology–Taiwan
The exhaust back pressure of diesel engines becomes increasing higher nowadays. As an example, the De-NOx system and DE-SOx system necessitated by the increasingly stringent emission standards, would result in increased exhaust back pressure for those diesel engines adopting such systems. Some ships adopt underwater exhaust system to save space on the working deck and to reduce noise and air pollution, while the hydrostatic pressure under water level has made the exhaust back pressure of diesel engines getting much higher. Under high exhaust back pressure, to keep discharging exhaust unhindered and operating smoothly for diesel engine, it often results in …
Elimination Of Noise In A Ship Cabin Using Multi-Layered Acoustic Boards: An Apso And Sa Approach,
2024
Department of Mechanical and Materials Engineering, Tatung University, Taiwan, ROC
Elimination Of Noise In A Ship Cabin Using Multi-Layered Acoustic Boards: An Apso And Sa Approach, Min-Chie Chiu, Ho-Chih Cheng
Journal of Marine Science and Technology–Taiwan
A high level of noise, combined with pure tones, is often encountered in ship's cabins, leading to severe psychological and physiological issues for the crew. To address this problem, an indoor noise abatement solution becomes necessary that utilizes efficient acoustic boards integrated with resonators, positioned along the inner walls of the cabin. However, the thickness of the acoustic boards must be strictly limited due to maintenance and operational considerations. This limitation results in insufficient sound absorption capabilities and a restricted range of tuned frequencies, as the resonating frequency of a standard Helmholtz resonator is closely tied to its cavity. A …
Numerical Study On The Aerodynamic Performance Of Four Flettner Rotors By Varying Distance And Spin Ratio,
2024
Shipbuilding & Marine Simulation Center, Tongmyong University, Busan, Republic of Korea
Numerical Study On The Aerodynamic Performance Of Four Flettner Rotors By Varying Distance And Spin Ratio, Janghoon Seo, Dong-Woo Park
Journal of Marine Science and Technology–Taiwan
The Flettner rotor is a wind-assisted propulsion system applied in eco-friendly ship to reduce greenhouse gas emissions. As the requirements of international regulations on greenhouse gas emissions become increasingly strict, multiple Flettner rotors are being applied, necessitating the evaluation of their performance with varying design parameters. The present study focuses on the aerodynamic performances of four Flettner rotors with variable design parameters of distance and spin ratio. Distances and spin ratios, including relative spin ratios, are considered. The drag and lift coefficients and lift-to-drag ratio of Flettner rotors are determined using Computational Fluid Dynamics (CFD), and the associated flow fields …
Underwater Image Enhancement Algorithm For Dual Color Spaces,
2024
Henan University, Software College, Longting District, Kaifeng, China, 475000
Underwater Image Enhancement Algorithm For Dual Color Spaces, Xingsheng Shen, Yalin Song, Shichang Li, Xiaoshu Hu
Journal of Marine Science and Technology–Taiwan
Targeting issues related to low contrast, blurring, and loss of detail prevalent in underwater image enhancement algorithms, we propose a dual-color space multiscale residual network (DMR-SCNet) based on SCNet. First, we introduce the HSV color space feature extraction module, which aims to optimize the color representation and saturation of underwater images. Subsequently, we propose the RGB color space denoising module, which focuses on repairing the content and structure of underwater images to enhance their clarity and visual quality. Finally, by designing the residual attention (RAB) module, we aim to further refine the detailed representation and feature extraction of underwater images. …
A Novel Identity Authentication Mechanism For Unmanned Maritime Vessels Communication Based On Mitre Att&Ck Framework,
2024
Dept. of Computer Science and Information Engineering Tamkang University New Taipei City, Taiwan
A Novel Identity Authentication Mechanism For Unmanned Maritime Vessels Communication Based On Mitre Att&Ck Framework, Junxian He, Shih-Hao Chang
Journal of Marine Science and Technology–Taiwan
With the development of the smart shipping industry, unmanned vessel technology is rapidly evolving, accompanied by a demand for robust Internet of Things (IoT) communication security practices. Key communication technologies for the operation of unmanned vessels include external vessel communication. One crucial aspect is the verification of the identities of the parties involved in these communication systems, as this ensures secure and trusted interactions between unmanned vessels and port management authorities. Identity authentication plays a vital role in ensuring the secure communication of unmanned vessels.This paper aims to analyze potential risks related to identity authentication technology in unmanned vessel communication …
Corrigendum To “Applicability Of Reducing Valve Timing Overlap For Diesel Engines Under High Exhaust Back Pressure”,
2024
National Taiwan Ocean University
Corrigendum To “Applicability Of Reducing Valve Timing Overlap For Diesel Engines Under High Exhaust Back Pressure”
Journal of Marine Science and Technology–Taiwan
No abstract provided.
Distribution And Population Structure Of Corallivorous Drupella Snails In The Coral Reefs Of Kenting In Taiwan,
2024
Department of Oceanography, National Sun Yat-sen University, Kaohsiung 804, Taiwan
Distribution And Population Structure Of Corallivorous Drupella Snails In The Coral Reefs Of Kenting In Taiwan, Chih-Jui Tan, Dun-Ru Kang, Li-Lian Liu
Journal of Marine Science and Technology–Taiwan
The corallivorous Drupella snails are common predators of living hard corals in the Indo-Pacific Ocean, and they can significantly threaten coral reef ecosystems when outbreaks occur. In Taiwan, a Drupella outbreak, which resulted in the dramatic decline of Acropora and Montipora corals, was reported in Penghu in 2002 – 2009. However, the Drupella species involved was not identified, and no further research has been conducted. To obtain current knowledge on the predation pressure of corallivorous snails on hard corals, we investigated benthic communities and the distribution and population structure of Drupella snails in the coral reefs of Kenting, Taiwan. The …
Evaluating The Connectivity Reliability Of The Seaborne Transportation Network Using Uncertainty Theory,
2024
School of Naval Architecture and Maritime, Zhejiang Ocean University, 316000, Zhoushan, China
Evaluating The Connectivity Reliability Of The Seaborne Transportation Network Using Uncertainty Theory, Tianshou Liu, Haiyang Bian, Lin Feng, Chenyang Fan, Chaojun Ding, Grifoll Manel, Hongxiang Feng
Journal of Marine Science and Technology–Taiwan
The shipping network serves as the backbone of international trade. However, due to unstable geopolitical conditions, unexpected events have occurred frequently in recent years that have impacted the global shipping supply chain, and this has placed enormous pressure and had adverse effects on seaborne transportation. To measure the reliability of the global shipping network under unexpected events, we abstract the global shipping network into a small world network using uncertainty theory. A method is proposed for selecting (i) the optimal reliable path and (ii) the optimal reliable path with a maximum measurement under different confidence intervals. Our approach is then …
Mechanical Property Analysis And Three-Dimensional Reverse Reconstruction Based On Corrosion Pit Characteristics Of Strong Corrosion Steel Plate,
2024
School of Civil Engineering and Architecture, Henan University of Science and Technology, Luoyang 471023, Henan, China
Mechanical Property Analysis And Three-Dimensional Reverse Reconstruction Based On Corrosion Pit Characteristics Of Strong Corrosion Steel Plate, Qiujun Ning, Xiaosong Lu, Jiawei Lu
Journal of Marine Science and Technology–Taiwan
To investigate the strong corrosion effect of 36% industrial hydrochloric acid on Q370 steel for bridges at room temperature. The surface morphology variations of the Q370 steel for bridges with corrosion time were measured and analyzed using a three-dimensional non-contact scanning profilometer. Subsequently, the standard monotonic tensile test was carried out to obtain the load-displacement curve and analyze the mechanical properties of the heavily corroded steel. Moreover, the constitutive model parameters of the heavily corroded steel were optimized. Furthermore, the heavily corroded steel model base on the actual corroded surface morphology was established, employing three-dimensional reverse reconstruction technology and finite …
