Ocean Engineering Commons^™

Control Of Flow Instabilities With Acoustic Metamaterials, Jensen E. Mctighe

Open Access Master's Theses

Acoustic metamaterials (AMs) have been proposed for uses in flow control, as they offer a passive control method and can be engineered independently, without needing complex fluid structure interactions simulations. For example, AMs embedded into flat plate surfaces have been demonstrated to delay (or speed up) the onset of laminar-to-turbulent boundary layer transition by attenuating (or strengthening) Tollmein-Schlicting waves through numerical simulation. However, as of present, no experimental research has been conducted to study or demonstrate the behaviors of AMs designed to interact with flow structures. An experiment was performed in which an AM was embedded into a flat plate …

Observability-Aware Path Planning For Autonomous Navigation, Raymond Brink Neistat

Open Access Master's Theses

Terrain-Aided Navigation (TAN) is a popular method of localization for GPS-denied vehicles, particularly in the marine domain. There are many ways to perform TAN in a marine setting, such as Bathymetric SLAM (BSLAM) and Bayesian Filtering with the aid of an a priori map. These techniques have been studied extensively, but show an overall lack of rigorous observability analyses. Without nonlinear observability analyses, TAN practitioners do not have an analytical indicator to know which areas of terrain will provide opportunities for the best localization performance. This thesis reviews current developments in the endeavors of nonlinear observability analyses as well as …

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, 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, 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, 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 …

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 …

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 …

Isolation And Characterization Of Caffeine-Degrading Bacteria From Coffee Plantation Areas In Malaysia, Elvina Clarie Dullah, Mohd Fazli Farida Asras

Makara Journal of Technology

Decaffeination by microbial degradation is currently the most optimal and low-cost approach, involving only microbial cells and/or their enzymes. The bacterium was characterized using a series of biochemical tests. Positive results were obtained from carbohydrate fermentation, citrate utilization, and catalase tests, while negative results were obtained from Voges-Proskauer (VP) and indole tests. Three different caffeine concentrations of 0.25%, 0.4%, and 2% were tested and measured through Gas Chromatography-Mass Spectrophotometry (GC-MS) analysis. The highest caffeine reduction (89.25%) was found when 0.25% caffeine was used in the media. Only a small amount of caffeine was reduced to 0.4% and 2%, with 34.78% …

Optimization Of The Building Envelope And Roof Shading To Reduce The Energy Consumption Of College Low-Rise Buildings In Indonesia, Nasruddin Nasruddin, Azimil Gani Alam, Mohammad Imroz Sohel

Makara Journal of Technology

Energy consumption in buildings is a crucial concern globally, prompting researchers to explore innovative solutions to mitigate its impact. This study investigates the optimization of building envelopes and roof shading systems of existing buildings in Indonesia to realize notable energy savings. Multiple scenarios were explored, with modifications to building envelopes and roof shading, highlighting the overall thermal transfer value as a key parameter. Using EnergyPlus simulations, the efficacy of natural ventilation in corridors and roof shading modifications was assessed in reducing energy consumption. The findings revealed that renovating existing buildings by optimization of the building envelope and roof shading by …

A Preliminary Study On Floating Flexible Otec Cold Water Pipe, Nai Kuang Liang, Hai Kuan Peng

Journal of Marine Science and Technology–Taiwan

Ocean Thermal Energy Conversion (OTEC) requires a large amount of cold seawater. The traditional rigid pipe, semi-rigidly fixed onto the ship bottom is not easy to install and disassemble, so the Floating Flexible Cold Water Pipe (FFCWP) flexibly connected to the ship is proposed. A small FFCWP was designed, fabricated, and successfully installed and recovered in the sea. The flexible pipe adopts commercially available fire ventilation snake pipe. The pipe wall material strength must be improved in the future. Assuming that the drag coefficient Cd value is 1.5, a numerical calculation is employed to simulate the FFCWP attitude from the …

Machine Learning With Multi-Source Data To Predict And Explain Marine Pilot Occupational Accidents, Gokhan Camliyurt, Youngsoo Park, Daewon Kim, Won Sik Kang, Sangwon Park

Journal of Marine Science and Technology–Taiwan

Marine pilot occupational accidents during transfer to/from ships are the primary concern of the International Marine Pilots’ Association (IMPA) and industry professionals. There are multiple transfer methods for marine pilots, with the most common being the pilot boat. To reach the mother ship bridge, the following stages must be safely completed: car transfer, walking on the pier, pier to pilot boat, pilot transfer by boat, cutter to pilot ladder, mother ship freeboard climbing, and ship deck to the bridge. Each stage has its own risk. Previous accident records and expert opinions are commonly used to conduct a risk analysis and …

Evaluation Of Operational Performance Of Wusongkou Cruise Port Through Network Data Envelopment Analysis, Qian-Feng Wang, Guo-Ya Gan, Xin-Liang Ye, Hsuan-Shih Lee

Journal of Marine Science and Technology–Taiwan

As major hubs for cruise berthing and passenger transfers, cruise ports in China were developing rapidly in the years before the COVID-19 pandemic because of an ever-growing regional market. Wusongkou Cruise Port is the most important port for cruise ships in China, and this study evaluated the operational performance of this port during 2011–2020. To this end, two-stage network data envelopment analysis was conducted to evaluate the port’s operation performance; subsequently, the change trajectory of the port’s operational efficiency during 2011–2020 was determined, and the potential reasons for the identified changes are discussed. Finally, suggestions for improving the operational performance …

A Review On Ship Recycling Industry In Bangladesh From Global Perspective, Ahammad Abdullah, Zobair Ibn Awal, M Ziauddin Alamgir, Md. Jobayer Mia, Farihatul Mim, Utpal K. Dhar

Journal of Ocean and Coastal Economics

At present, the global center of the ship breaking and recycling industry is in South Asia, specifically Bangladesh, India, and Pakistan. These three countries account for 70–80 percent of the international recycling market for ocean-going vessels, with China and Turkey covering most of the remaining market. Only about 5 percent of global volume is scrapped outside these five countries. Bangladesh has environmentally beneficial coastal region and affordable labor that make the shipbreaking and recycling business as a potential sector for the country. In addition, ship recycling and its related businesses are helping to solve our nation’s unemployment issues at all …

Deep Ocean Vehicle Applications And Modifications, Nichole "Nikki" T. Arm

Master's Theses

This project had two primary goals: (1) to explore opportunities to further a deep-ocean vehicle’s reach using alternative pressure spheres, and (2) to implement an existing deep-ocean vehicle (lander) in active scientific research.

I gained a greater understanding of the limitations and design choices made for existing pressure spheres using Finite Element Analysis (FEA). My simplified FEA model predicted sphere failure for the existing 30% Fiber Glass 70% Nylon injection molded spheres at an external pressure of 3,954psi or 2,690m ocean-depth (only a 7.38% error compared to the tested minimum failure depth), so I determined it a valid model. I …

Maitreya Desalination, Riley Taft, Hudson Kispert, Brendan Dizon

Mechanical Engineering

This document relays the design and manufacture of a dual power input Reverse Osmosis desalination unit. It's power sources are electric drive and human power via recumbent seated cycling. Fresh water outputs range from 4 - 7 GPH for human power inputs of 150 - 280 Watts depending on the selected gearing ratio from the derailleur.

Physics-Based Machine Learning Methods For Control And Sensing In Fish-Like Robots, Colin Rodwell

All Dissertations

Underwater robots are important for the construction and maintenance of underwater infrastructure, underwater resource extraction, and defense. However, they currently fall far behind biological swimmers such as fish in agility, efficiency, and sensing capabilities. As a result, mimicking the capabilities of biological swimmers has become an area of significant research interest. In this work, we focus specifically on improving the control and sensing capabilities of fish-like robots.

Our control work focuses on using the Chaplygin sleigh, a two-dimensional nonholonomic system which has been used to model fish-like swimming, as part of a curriculum to train a reinforcement learning agent to …

Underwater Image Enhancement: A Pipeline For Underwater Computer Visions, Humberto Lebron Rivera

Theses and Dissertations

Ocean exploration has surged in popularity and significance in recent years, including diverse areas like maritime archeology, underwater resources, and submerged structure inspection. The activities mentioned above heavily depend on vision and imagery, a challenge in the unpredictable marine world. This thesis presents a conditional generative adversarial network model for image-to-image translation problems. We designed and trained the model with the end goal of enhancing underwater images. Five metrics were employed for validation to quantify our model’s resulting enhanced images. By doing so, we aim to establish a pipeline that can leverage aerial computer vision algorithms for marine applications.

Our …

Project Thetis: A Low-Cost, Low-Profile Inertial Data Logger, Braidan Duffy

Theses and Dissertations

This thesis details the design, testing, calibration, and verification of a nine degree of freedom inertial measurement data logger for use with floating bodies. The instrument was conceived to address limitations of equipment used in classes within the Ocean Engineering department at Florida Institute of Technology. By meeting with several stakeholders and end users, a series of stakeholder requirements, capabilities, and component-level requirements were de- veloped that informed the design constraints. There were several hardware iterations of the board, culminating in Revision F5 which was extensively tested and proven. The design was inspected after testing concluded to determine which capabilities …

Effects Of Perforations On Internal Cathodic Protection And Recruitment Of Marine Organisms To Steel Pipes, Alexander John Paluzzi

Theses and Dissertations

Steel monopile support structures for offshore wind turbines require protection from corrosion on their external and internal surfaces. Cathodic protection (CP) works effectively to protect the external surfaces of monopiles, but internally, byproducts from aluminum sacrificial anode CP (SACP) and impressed current CP (ICCP) induce acidification that accelerates steel corrosion. This project investigated the effects of perforations on the performance of aluminum SACP and ICCP when used inside of steel pipes. Additionally, marine growth on the external and internal surfaces of the pipes was assessed to determine if CP byproducts affect marine organism development.

Two sealed and two perforated steel …