Ocean Engineering Commons^™

Reynolds-Averaged Navier-Stokes Simulations Of Nearshore Langmuir Circulation And The Formation Of Oil-Particle Aggregates, Juan J. Penaloza Gutierrez

USF Tampa Graduate Theses and Dissertations

Langmuir turbulence in the inner shelf coastal ocean is characterized by Langmuir circulation (LC) or cells that can span the full depth of unstratified water columns. A Reynolds-averaged Navier-Stokes (RANS) simulation strategy resolving full-depth LC coupled with an oil-particle aggregate (OPA) formation model is introduced. The RANS methodology is employed in two different cases. The first case corresponds to a shallow shelf zone of uniform depth, focusing on vertical mixing and transport of OPAs. The second case pertains to a surf-shelf transition zone with variable depth, comprising vertical and horizontal mixing of OPAs. In the latter case, a wave model …

Reducing Uncertainty In Sea-Level Rise Prediction: A Spatial-Variability-Aware Approach, Subhankar Ghosh, Shuai An, Arun Sharma, Jayant Gupta, Shashi Shekhar, Aneesh Subramanian

I-GUIDE Forum

Given multi-model ensemble climate projections, the goal is to accurately and reliably predict future sea-level rise while lowering the uncertainty. This problem is important because sea-level rise affects millions of people in coastal communities and beyond due to climate change's impacts on polar ice sheets and the ocean. This problem is challenging due to spatial variability and unknowns such as possible tipping points (e.g., collapse of Greenland or West Antarctic ice-shelf), climate feedback loops (e.g., clouds, permafrost thawing), future policy decisions, and human actions. Most existing climate modeling approaches use the same set of weights globally, during either regression or …

Smart Sounding Table Using Adaptive Neuro-Fuzzy Inference System, Osman Ünal, Nuri Akkaş

Journal of Marine Science and Technology–Taiwan

Marine engineers measure the liquid level (sounding depth) to calculate the volumetric content of a ship's tank. The sounding depth is determined using an ullage pipe located at specific points on the tanks. To estimate the accurate volume of liquid, considering the ship's trim and heel conditions, engineers use a tank table (sounding table) consisting of hundreds of pages. However, this method is time-consuming and lacks intermediate values for sounding depth, trim, and heel. Ship designers recommend to use linear interpolation for intermediate values, yet this process is also time-consuming. This paper proposes the implementation of an Adaptive Neuro-Fuzzy Inference …

Case Study Of Coastal Erosion And Measures At Kezailiao Coast, Taiwan, Tai-Wen Hsu, Yi-Tse Tu, Jen-Yi Chang

Journal of Marine Science and Technology–Taiwan

This paper examines major factors of coastal erosion and measures against beach erosion at Kezailiao Coast, Taiwan. Typical examples of coastal erosion due to natural or man-made factors are reviewed. Case studies of countermeasure for beach erosion are addressed. We further analyze and discuss historical shoreline and coastal cliff recession as a result of the attack of storm surges and waves. The coastline mainly made up of cliffs (2-3m high), made of soft, easily eroded boulder sand and clay. In total, 3km of land have been lost since 1951, including villages and farm buildings. The most important impacts of beach …

Wearable Sensor-Based Walkability Assessment At Ferry Terminal Using Machine Learning: A Case Study Of Mokpo, Korea, Jungyeon Choi, Hwayoung Kim

Journal of Marine Science and Technology–Taiwan

Walkability assessments are becoming more popular, as walking offers numerous health, environmental, and economic benefits to communities. However, previous studies on ferry terminal walkability assessment have been inadequate. This study aimed to develop a wearable sensor system to automatically assess walkability at ferry terminals without conducting surveys. We applied seven machine learning (ML) classifiers to detect different walking environments, including flat ground (FG), downhill slope (DS), uphill slope (US), and uneven surface (UE). The ML models were evaluated across different combinations of classes: 2-class (FG vs. UE), 3-class (U) (FG vs. US vs. UE), 3-class (D) (FG vs. DS vs. …

Application Of Blockchain Technology In Aquaculture Management, Yu-Jen Pan, Hsin-Pei Shieh

Journal of Marine Science and Technology–Taiwan

In recent years, food safety has become a growing concern in Taiwanese society. To ensure efficient management of the supply chain within the L Aquatic Products company, it is imperative to employ reliable technical support in establishing an effective traceability management system. The traceability of products can provide managers with valuable insight into the intricacies of the supply chain. By establishing a dependable food traceability system, brand trust can be strengthened, and consumers can inquire about the movement of aquatic products within the supply chain. Blockchain technology offers features such as traceability, accountability, transparency, reliability, trust, privacy, and security, making …

Production Of Ground Granulated Blast-Furnace Slag Cement: Energy And Carbon Reduction Efficiency Of Cement-Grinding System, Kuan-Hung Lin, Chung-Chia Yang

Journal of Marine Science and Technology–Taiwan

This study used clinker, ground granulated blast-furnace slag (GGBS), and gypsum in a cement-grinding system to produce GGBS cement (GCE). Gypsum was used as the alkaline activator to modify the surface area of GCE and increase its compressive strength. The results revealed that the use of the gypsum activator and the modification of the surface area of GCE effectively increased the formerly inadequate compressive strength of GCE (GGBS > 60%) in the early stage. In addition, energy consumption data were obtained during the production of GCE and Portland cement (PCE) by the cement-grinding system. The calculations concerning the production proportions indicated …

Challenges In Optimization For The Performance On Sustainability Dimensions In Reverse Logistics Social Responsibility, Sumarsono Sudarto, Katsuhiko Takahashi, Mochammad Dewo

Makara Journal of Technology

Reverse logistics social responsibility is preferred as the most acceptable solution for addressing the challenges in stakeholders’ debate regarding social responsibility in supply chains because it involves as many actors as possible in the supply chain to perform social responsibility to achieve sustainability. This paper explores the challenges in achieving optimal policies in sustainability dimensions for collection and recycling facilities in reverse logistics. Sustainability dimensions include economic, environmental, and social aspects. The reverse logistics is modeled on System Dynamics, and a simplified statistical analysis using a contour chart is employed in numerical experiments. Results show a narrow area of optimal …

Construction Of A Real-Time Forecast Model With Deep Learning Techniques For Coastal Engineering & Processes: Nested In Basin Scale Suite Of Models, Md Ahsan Habib

Theses and Dissertations

The study aims to develop a robust and adaptable real-time forecasting system for coastal and estuarine regions, considering the challenges of limited or unavailable forecast data. To address the challenge of data unavailability, this study proposes the application of a deep learning model (DLM). This research involves the development of a high-resolution numerical model nested within global models. Calibration and validation are performed by comparing the model with observed data. The study explores the effects of various parameters, such as vertical resolution, wind variability, and bottom roughness, on model performance. It finds that the 10-layer model improves vertical stratification and …

Algorithms For The Generalized Inverse Solution And Direct Solution: Using An Algebra Computer-Based System To Obtain Meridian Arc Length, Wei-Kuo Tseng, King-Cheng Tsai, Chian Liou, Jiunn-Liang Guo, Yi-Jia Sun

Journal of Marine Science and Technology–Taiwan

In this study, the idea employed in the article of [1] to treat the problem of the arc-length of meridian is applied to the arc-length determined by the third flattening (n) instead of the eccentricity (e) of an Earth-reference ellipsoid . With WGS 84 ellipsoid datum used in modern navigation, the meridian arc-length is a crucial factor for map projections and geodetic and distance calculations such as Mercator charts, the universal transverse Mercator, great circle (ellipse), rhumb line, and geodesic. Because navigation software lacks officially standardized calculation methods, these “black box solutions” used in navigational systems are unknown. Therefore members …

Three-Dimensional Higher-Order Compressive Sensing For Raypath Separation In An Acoustic Waveguide, Fengyan Zhong

Journal of Marine Science and Technology–Taiwan

In an acoustic waveguide, the separation of multiple raypaths, especially close raypaths, is a challenging task in the presence of colored noise due to interference in the acoustic eld. In this paper, a three-dimensional higher-order compressive sensing method for raypath separation is proposed. The method is applied on an array-to-array experimental conguration where both emitter and reception arrays are used. With the array-to-array conguration, the raypaths are characterized by three parameters including arrival direction, departure direction, and arrival time. Furthermore, the performance of the proposed algorithm is illustrated by simulations and experiments. The numerical results based on simulation illustrate that …

Projection Of Sea Surface Temperature Based On Empirical Mode Decomposition And Its Application In Typhoon Number Forecast, Wen-Cheng Huang, Jung-Chen Lee

Journal of Marine Science and Technology–Taiwan

The primary objective of this paper is to demonstrate the applicability of empirical mode decomposition (EMD) in projecting non-stationary daily sea surface temperature (SST) series, and the other is to apply the projected series of SST to estimate the number of typhoons. The study focuses on an area ranging from 5°N~25°N and 110°E~170°E, collecting daily sea temperature data and typhoons records within this region. The findings conclusively indicate that the EMD-based data generation method proposed in this paper can effectively addresses the limitations of previous hydrological models in generating non-stationary series, signifying a significant advancement in hydrological time series modeling …

Wave Energy Converter For Marine Vessels And Isolated Communities, Leo Kirshenbaum, Owen Pyle, Gage Howard, Charlie Camilli, Jonathan Ma, Emigdio Islas, Joseph Bonafede

Mechanical Engineering

California Polytechnic State University’s 2023 Marine Energy Collegiate Competition team, Surf Supply, has developed a floating dock that transduces wave energy into electricity. The following report aligns with MECC requirements, and our design changes since CDR are present in the User Manual in Appendix F. Our primary market research of the Blue Economy identified electric marine vessel charging and isolated communities as early adopters that could benefit most from the first generation of our wave energy converter (WEC). Surf Supply’s design concept provides a reliable, affordable, and renewable energy source that reduces dependency on conventional fossil fuels, allowing blue economy …

Development Of A Low-Cost Acoustic Gauge For Simultaneous Tide And Wave Measurement, Alexander Kalman Dunn

Master's Theses

High-quality tide and wave data are essential in a variety of fields including coastal engineering, climate science, disaster response, and recreational activities. Accurate data are publicly accessible from government organizations such as the National Oceanic and Atmospheric Administration (NOAA), however the high costs associated with deploying and maintaining their high accuracy gauges results in a deficit of localized data. Commercial gauges available starting at $2,000 are still expensive for local agencies and individual users to deploy and maintain. These commercial options can also be limited in their scope, accuracy, or ease of use. In this thesis, a low-cost acoustic gauge …

Importance Of Vegetation In Tsunami Mitigation: Evidence From Large Eddy Simulations With Fluid-Structure Interactions, Abhishek Mukherjee

Dissertations

Communities worldwide are increasingly interested in nature-based solutions like coastal forests for the mitigation of coastal risks. Still, it remains unclear how much protective benefit vegetation provides, particularly in the limit of highly energetic flows after tsunami impact. The present thesis, using a three-dimensional incompressible computational fluid dynamics model with a fluid-structure interaction approach, aims to quantify how energy reflection and dissipation vary with different degrees of rigidity and vegetation density of a coastal forest.

In this study, tree trunks are represented as cylinders, and the elastic modulus of hardwood trees such as pine or oak is used to characterize …

Sensor Updates For Bigheaded Carp-Tracking Autonomous Boat, Jordan Kaufmann

Honors College Theses

Bigheaded carp are an invasive species that overpopulate and compete with the native species of Kentucky Lake as well as many other North American aquatic ecosystems. The movement patterns of Bigheaded carp are being studied nationwide by the United States Geological Survey and multiple universities. These studies ultimately seek to control their spread and reduce or reverse the ecosystem destabilization caused by this invasive species. Such studies are currently conducted manually on Kentucky Lake by graduate students affiliated with the Murray State University (MSU) Biology Department and Hancock Biological Station, and these manual studies are an arduous and time-consuming effort. …

Deep Learning Of Semantic Image Labels On Hdr Imagery In A Maritime Environment, Charles Montagnoli

Doctoral Dissertations and Master's Theses

Situational awareness in the maritime environment can be extremely challenging. The maritime environment is highly dynamic and largely undefined, requiring the perception of many potential hazards in the shared maritime environment. One particular challenge is the effect of direct-sunlight exposure and specular reflection causing degradation of camera reliability. It is for this reason then, in this work, the use of High-Dynamic Range imagery for deep learning of semantic image labels is studied in a littoral environment. This study theorizes that the use HDR imagery may be extremely beneficial for the purpose of situational awareness in maritime environments due to the …

Estimating Remaining Life And Fitness-For-Services Evaluation Of Fuel Piping Systems, Sekar Putri Purwidyasari, Ahmad Isni Kurniawan, Deni Ferdian

Journal of Materials Exploration and Findings

Assets life extension are required to predict the design life expiry based on condition and effects of deterioration. The remaining life assessment will answer the questions about timing of the component or equipment will lead to failure and shall be evaluated by inspection and maintenance monitoring. This study elaborates process calculation and analysis by using remaining life assessment and fitness for services method according to API 579-1/ASME FFS-1 for process piping area. The result of remaining useful life estimation and estimated life has been proposed. There are 11 piping systems based on the condition monitoring with thickness measurements. The result …

Predicting Near-Bed Sediment Transport Through Particle Image Velocimetry, Caroline Hoch

Theses and Dissertations

Erosion and accretion are coastal processes that directly affect the safety of coastal communities. Dimensionless parameters, such as the Shields and Ursell number, have historically been used to predict sediment motion in the nearshore region based on shear stress and wave linearity. This study uses particle image velocimetry to measure the velocity field of sediment within a wave flume and calculate these parameters for various wave profiles. Five regular wave trials and five irregular wave trials were run within the wave flume at varying depths to model how net transport changes as waves approach the shoreline. An instantaneous Shields number …

An Exploration Of The Application Of Desalination In Disaster Relief, Emma Sager

Senior Honors Theses

This paper aims to explore the application of small-scale desalination systems to provide clean water in the wake of marine natural disasters. A lack of clean water is a devastating impact of many natural disasters. Desalination technologies, both thermal and membrane, show potential for being scaled down and self-powered by renewable energy. Desalination can transform ocean water and contaminated drinking water with a high salt content into drinkable, usable water. While these techniques are not perfected, and the solution to a need for clean water is multifaceted, desalination shows potential. Through further research and ever-advancing technology, small-scale desalination could develop …