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Journal of Marine Science and Engineering
Number of Followers: 4  Open Access journalISSN (Online) 2077-1312 Published by MDPI  [258 journals]
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- JMSE, Vol. 13, Pages 479: Research on LSTM-PPO Obstacle Avoidance
Algorithm and Training Environment for Unmanned Surface Vehicles
Authors: Wangbin Luo, Xiang Wang, Fang Han, Zhiguo Zhou, Junyu Cai, Lin Zeng, Hong Chen, Jiawei Chen, Xuehua Zhou
First page: 479
Abstract: The current unmanned surface vehicle (USV) intelligent obstacle avoidance algorithm based on deep reinforcement learning usually adopts the mass point model to train in an ideal environment. However, in actual navigation, due to the influence of the ship model and the water surface environment, the training set is triggered. The reward function does not match the actual situation, resulting in a poor obstacle avoidance effect. In response to the above problems, this paper proposes a long and short memory network-proximal strategy optimization (LSTM-PPO) intelligent obstacle avoidance algorithm for non-particle models in non-ideal environments, and designs a corresponding deep reinforcement learning training environment. We integrate the motion characteristics of the unmanned boat and the influencing factors of the surface environment, based on the curiosity-driven set reward function, to improve its autonomous obstacle avoidance ability, combined with the LSTM network to identify and save obstacle information to improve the adaptability to the unknown environment; virtual simulation is performed in Unity. The engine builds a USV physical model and a refined water deep reinforcement learning training environment including a variety of obstacle models. The experimental results demonstrate that the LSTM-PPO algorithm exhibits an effective and rational obstacle avoidance effect, with a success rate of 86.7%, an average path length of 198.52 m, and a convergence time of 1.5 h. A comparison with the performance of three other deep reinforcement learning algorithms reveals that the LSTM-PPO algorithm exhibits a 21.5% reduction in average convergence time, an 18.5% reduction in average path length, and an approximately 20% enhancement in the success rate of obstacle avoidance in complex environments. These results indicate that the LSTM-PPO algorithm can effectively enhance the search efficiency and optimize the path planning in obstacle avoidance for unmanned boats, rendering it more rational.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-02-28
DOI: 10.3390/jmse13030479
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 480: Prescribed-Time Formation Tracking Control for
Underactuated USVs with Prescribed Performance
Authors: Bowen Sui, Jianqiang Zhang, Zhong Liu
First page: 480
Abstract: This article proposes a prescribed-time formation tracking control scheme for USVs with prescribed performance constraints to address the issue of multiple underactuated USV formation tracking control with external environmental disturbances and input saturation. Initially, a prescribed-time extended state observer was constructed, capable of promptly estimating and compensating for speed and external disturbances within a certain timeframe. Additionally, a unique performance function was developed, enabling the performance function to converge to a predetermined accuracy within a specified time, while allowing for flexible adjustment of the performance constraint shape by parameter modification. Furthermore, a prescribed-time formation control algorithm was developed by combining graph theory and dynamic surface control, enabling the formation error to converge within preset performance constraints at a specified period of T = 10 s. It was proved that all signals in the closed-loop system are uniform, ultimately bounded by Lyapunov stability theory and the formation tracking errors display prescribed-time stability. Finally, the efficacy and superiority of the designed control scheme were evaluated by constructing numerical simulations.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-02-28
DOI: 10.3390/jmse13030480
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 481: Assessment of the Fish Stock Status of the
Spangled Emperor Lethrinus nebulosus Along the Coast of Balochistan,
Pakistan
Authors: Aidah Baloch, Qun Liu, Muhsan Ali Kalhoro, Aamir Mahmood Memon, Suman Barua, Xu Chen, Hasnain Raza, Yihong Ma
First page: 481
Abstract: The sustainable exploitation of fishery resources in Pakistan was assessed using the catch-based Monte Carlo method (CMSY) and the length-based Bayesian biomass (LBB) method to evaluate the data-limited fishery of the Spangled Emperor, Lethrinus nebulosus. CMSY relies on catch data, resilience parameters, and quantitative stock status metrics, while LBB exclusively uses length–frequency (LF) data for stock assessments. This study utilized twenty-two years of catch–effort and LF data from 7230 fish along the Balochistan coastline in Pakistan. The study revealed that the relative biomass of the exploited stock, with a B/BMSY ratio of 0.557, indicates significant depletion. The relative exploitation rate (F/FMSY = 2.47) confirms that the stock is being severely overfished. The discrepancy between the optimal length at first capture (Lc_opt = 43.1 cm) and the length at first capture (Lc = 38.8 cm) further proves the overexploitation of L. nebulosus. The convergence of findings from both methodologies strengthens the reliability of stock status estimates. By integrating diverse data types and analytical frameworks, this study provides valuable insights into the sustainability of L. nebulosus populations. This dual approach not only underscores the importance of varied data sources but also informs management strategies for effective fisheries conservation, contributing to a deeper understanding of resource dynamics along the Balochistan coast of Pakistan.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-02-28
DOI: 10.3390/jmse13030481
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 482: Spatial Orientation Relation Recognition for
Water Surface Targets
Authors: Peiyong Gong, Kai Zheng, Yi Jiang, Huixuan Zhao, Xiao Liang, Zhiwen Feng, Wenbin Huang
First page: 482
Abstract: Recently, extensive research efforts have concentrated on comprehending the semantic features of images in the field of computer vision. In order to address the spatial orientation relations among water surface targets (WSTs) in an image, which is a fundamental semantic feature, this paper focused on the recognition of spatial orientation relations. We first developed the water surface target spatial orientation vector field (WST-SOVF) algorithm, a novel end-to-end methodology, to recognize these spatial orientation relations among WSTs in an image. The WST-SOVF algorithm encodes the spatial orientation relation into the learning framework of a new deep convolutional neural network model, which comprises two distinct branches: the T-branch and the S-branch, both designed for the spatial feature extraction. The T-branch employs keypoint estimation to identify central points and classify the WST categories, while the S-branch constructs a spatial orientation vector field between WSTs, where each pixel in the field encodes the spatial orientation angle between two separated WSTs and collectively determines the category of spatial orientation. A fusion module was also designed to integrate the spatial feature obtained from both branches, thereby generating a comprehensive triple list that provides not only all the WSTs and their spatial orientation relations, but also their associated confidence levels. We performed a comparative evaluation of our WST-SOVF algorithm based on Huawei’s “Typical Surface/Underwater Target Recognition” dataset and the results demonstrated the outstanding performance of WST-SOVF algorithm.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-02-28
DOI: 10.3390/jmse13030482
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 483: Linking Volcanism, Hydrothermal Venting, and
Ordovician/Silurian Marine Organic-Rich Sediments in the Eastern Sichuan
Basin, Southwest China
Authors: Shaojie Li, Zhou Zhu, Qilin Xiao, Suyang Cai, Huan Li
First page: 483
Abstract: The Ordovician/Silurian boundary (Wufeng/Longmaxi formations) in the Shizhu region, eastern Sichuan Basin, China hosts organic-rich black shales which are frequently interbedded with bentonite and hydrothermal minerals (e.g., pyrite). This study investigated the mineralogical, total organic carbon (TOC), total sulfur (TS), and major and trace element compositions of organic-rich samples. Non-visible volcanic input is identified to influence organic matter accumulation, as shown by the correlations between TOC and proxies, including Zr and Hf contents and the Cr/Al2O3, V/Al2O3, Ni/Al2O3, and SiO2/Al2O3 ratios. Redox indicators (V/Cr, v/v + Ni, degree of pyritization (DOP), U/Th, and Mo contents) display positive correlations with TOC values, suggesting that an oxygen-depleted environment is necessary for organic matter (OM) preservation. The TOC values exhibit better regression coefficients (R2) against redox indicators, including DOP (0.43), U/Th (0.70), and Mo contents (0.62), than V/Cr (0.16) and v/v + Ni (0.21). This may because some V, Cr, and Ni is hosted in non-volcanic ashes within shales but not inherited from contemporaneous water columns. The greater scatter in TOC-DOP and TOC-Mo relative to TOC-U/Th relations may result from hydrothermal venting in shales, evidenced by the coexistence of framboid and euhedral pyrite and the previous finding of hydrothermally altered dolomites in the studied sections. There is no systematic relation between TOC and Ni/Co ratios, and this means that portions of Ni are contributed by non-visible volcanic ashes and Ni and Co are redistributed during the precipitation of hydrothermal pyrites due to their strong chalcophile affinities. Such a feature may further suggest that most pyrites are precipitated during hydrothermal venting. The DOP displays broad correlations with non-visible volcanic indicators, supporting that hydrothermal venting may be triggered by volcanic activities. The outcomes of this study highlight that caution is necessary when evaluating the sedimentary facies features of volcanism-affected organic-rich black shales with the used metallic proxies.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-02-28
DOI: 10.3390/jmse13030483
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 484: Structural Failure Modes of Single-Story Timber
Houses Under Tsunami Loads Using ASCE 7’S Energy Grade Line Analysis
Authors: Darko Otey Mayorga, Juan Carlos Vielma, Patricio Winckler
First page: 484
Abstract: The structural response of single-story timber houses subjected to the 27 February 2010 Chile tsunami is studied in San Juan Bautista, an island town located nearly 600 km westward from the earthquake’s rupture source, in the Pacific Ocean. The ASCE 7-22 energy grade line analysis (EGLA) is used to calculate flow depths and velocities as functions of the topography and recorded runup. To understand the structural response along the topography, reactions and displacements are computed at six positions every 50 m from the coastline. Houses are modeled using the Robot software, considering dead and live loads cases under the Load and Resistance Factor Design (LRFD) philosophy. The results show that houses located near the coastline experience severe displacements and collapse due to a combination of hydrodynamic forces, drag and buoyancy, which significantly reduces the efficiency of the foundations’ anchorage. Structures far from the coastline are less exposed to reduced velocities, resulting in decreased displacements, structural demand and a tendency to float. Finally, the methodology is validated by applying a nonlinear analysis of the structures subjected to tsunami loads at the different positions considered in this study. Despite their seismic resistance, lightweight timber houses are shown to not be suitable for areas prone to tsunamis. Tsunami-resilient design should therefore consider heavier and more rigid materials in flooding areas and the relocation of lightweight structures in safe zones.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-02-28
DOI: 10.3390/jmse13030484
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 485: Research on the Dynamic Stability of AC/DC
Hybrid Microgrids in New-Energy Ships
Authors: Bing Wang, Wanneng Yu, Weiqiang Liao, Yibin Fang, Changkun Zhang, Rongfeng Yang
First page: 485
Abstract: For the frequent occurrence of pulse power load operation and load switching disturbances in AC/DC shipboard microgrids, a large-signal stability analysis method based on hybrid potential theory is proposed. The proposed method utilizes a mixed potential function to analyze the impact of interconnected converters on system stability. First, the entire system is equivalently modeled as a DC system in a d-q rotating reference frame. Then, a mixed potential function model of the AC/DC system is established for stability analysis, leading to the development of a large-signal stability criterion for the system. Using this criterion, the boundary values of bidirectional power transfer for the interconnected converters are derived. Finally, a simulation model of the AC/DC hybrid microgrid system was built in Simulink for verification, and further validation was carried out on the RT-lab hardware-in-the-loop (HIL) simulation platform. Simulation and experimental results show that the proposed criterion can effectively ensure the stability of the AC/DC hybrid microgrid system under large disturbances.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-02-28
DOI: 10.3390/jmse13030485
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 486: Optimization Design of Blades Based on
Multi-Objective Particle Swarm Optimization Algorithm
Authors: Li, Wang, Xie, Li
First page: 486
Abstract: Among renewable energy sources derived from the ocean, wind power has developed rapidly. This article proposes an optimization algorithm framework that integrates two objectives: aerodynamic shape optimization and structural optimization. For practical reasons, the 5−MW wind turbine blade was selected as the research object, and the sea conditions near the East China Sea were chosen as the environmental parameters for its service environment. The FAST simulation software was employed for verification purposes. The results indicated that the optimized blade not only meets the target power output but also possesses unique economic advantages, such as being lightweight and exhibiting low aerodynamic force.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-02-28
DOI: 10.3390/jmse13030486
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 487: CFD-Based Optimization of an Axial Impulse
Turbine for a Twin-Turbine Topology of an OWC Wave Energy Converter
Authors: Hosam M. Abdul-Hasieb, Aitor Vega-Valladares, Manuel García-Díaz, Bruno Pereiras, José González Pérez
First page: 487
Abstract: Oscillating water column (OWC) devices have been among the most extensively studied wave energy converters over the past decade. This paper focuses on a specific OWC configuration that employs twin unidirectional axial turbines, which alternate their operation to generate energy based on the oscillating motion of the water’s free surface. Despite numerous studies, these turbines have never undergone a comprehensive optimization process. This study presents an optimization process applied to a previously documented turbine geometry to determine an optimal design based on a five-parameter selection. The optimization was conducted using a genetic aggregation method aimed at maximizing efficiency in direct flow mode. A computational fluid dynamics (CFD) model, validated against experimental data, was used to construct the response surface for the optimization. The results demonstrated a 28% increase in efficiency at low flow coefficients compared to the original design. The optimized geometry significantly reduced energy losses, with reductions of approximately 66.2% and 22.3% at flow coefficients of Ø = 0.25 and Ø = 0.50, respectively. Furthermore, an unsteady performance evaluation revealed a 12% increase in the turbine’s peak efficiency and a 2% improvement in blocking efficiency compared to the initial design.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-02-28
DOI: 10.3390/jmse13030487
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 488: The Structure and Near-Bottom Magnetic Anomaly
Characteristics of the Daxi Vent Field on the Carlsberg Ridge,
Northwestern Indian Ocean
Authors: Puchen Zhao, Zhaocai Wu, Xiqiu Han, Yejian Wang, Jialing Zhang, Qiang Wang
First page: 488
Abstract: Seafloor hydrothermal vent areas are potential sources of polymetallic sulfide deposits and exhibit distinct mineralization structures under different tectonic settings. The Daxi Vent Field (DVF), located on the Carlsberg Ridge in the northwestern Indian Ocean, represents a basalt-hosted hydrothermal system. To investigate the alteration zone structure of the DVF, high-resolution near-bottom bathymetric and magnetic data were collected during the Chinese DY57 expedition in 2019. Based on the results of magnetic anomaly data processing, including reduction to a level surface and Euler deconvolution, the location and depth of the magnetic sources were identified. In addition, two 2.5D magnetic forward models crossing the active and inactive vent fields were constructed. The results indicate that the range of the alteration zone in the active vent at the DVF extends up to 120 m in width and 80 m in depth, while the hydrothermal deposit at the extinct vent on the northeastern side extends up to 220 m along the ridge axis with a thickness of 30 m.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-01
DOI: 10.3390/jmse13030488
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 489: Fine Sediment Dispersion in the Addu-City
Dredging and Reclamation Project
Authors: Efstratios N. Fonias, Erik van Eekelen, Barend van den Bosch
First page: 489
Abstract: The matter of the quantification of the fraction of the dredged sediment that is released by a trailing suction hopper dredger into the surrounding waters, also known as the passive phase of the plume during dredging operations through the overflow, is a rather complex process. A number of processes, including sediment settling, propeller wash, and entrapment of air during sediment release, are only a few of the reasons why plumes are formed and sediments because of the overflow are released back into the environment. The present work attempts to examine the empirical considerations used for the estimation of the amount of sediments expected to be released through the overflow or via a reclamation by looking into the case of the Addu-City dredging and reclamation project. Moreover, the effectiveness of silt curtains as a turbidity containment measure is discussed. Based on the field data collected, it can be concluded that under normal hydrodynamic conditions, from the sediment source calculated based on the existing literature, only 20% of the fine sediments is available for dispersion. Moreover, the accurate and consistent follow-up of the work schedule execution and consistent monitoring as a part of environmental management can ensure compliance with environmental regulations further away from the project area.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-01
DOI: 10.3390/jmse13030489
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 490: ANFIS-Based Course Controller Using MMG
Maneuvering Model
Authors: Yu Guo, Rui Yang, Zhiheng Zhang, Bing Han
First page: 490
Abstract: In the domain of course control, traditional methods such as proportional–integral–derivative (PID) control often exhibit limitations when addressing complex nonlinear systems and uncertain disturbances. To mitigate these challenges, the adaptive neuro-fuzzy inference system (ANFIS) has been integrated into course control strategies. The primary objective of this study is to investigate the course control characteristics of vessels governed by the ANFIS controller under both normal and severe sea conditions. A three-degree-of-freedom (3-DOF) maneuvering model set (MMG) was employed and validated through sea turning tests. The design of the ANFIS controller involved a combination of the backpropagation algorithm with the least square method. Training data for the ANFIS control system were derived from a linear control framework, followed by simulation tests conducted under normal and severe sea conditions to assess control performance. The simulation results indicate that in normal sea conditions, ANFIS has more stable heading control (smaller Aψ), but at the cost of more energy consumption (larger Iδ). Notably, response time is reduced by approximately 36.7% compared to that of the linear controller. Conversely, during severe sea conditions, ANFIS exhibits an increase in response time by about 33.3% relative to the linear controller while maintaining a smaller Iδ. In the whole course control stage, the stability is better than the linear controller, and it has better energy-saving characteristics. Under scenarios involving small and large course alterations, Aψ values for ANFIS are approximately 11.28% and 13.97% higher than those observed with the best-performing linear controller (λψ = 60), respectively. As the propeller speed increases, the Aψ value of the ANFIS controller decreases significantly, to about 62.71%, indicating that the energy efficiency is improved and the course stability is also enhanced. In conclusion, it can be asserted that the implementation of an ANFIS controller yields commendable performance in terms of controlling vessel courses effectively.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-01
DOI: 10.3390/jmse13030490
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 491: A Prioritization Framework for Adaptation
Responses for Climate Change-Induced Erosion in Island Beaches—Cases
from the Aegean Islands, Greece
Authors: Isavela N. Monioudi, Dimitris Chatzistratis, Theodoros Chalazas, Antonis E. Chatzipavlis, Adonis F. Velegrakis, Olympos P. Andreadis, Efstratios N. Monioudis, Antigoni Nikolaou, Thomas Hasiotis
First page: 491
Abstract: This contribution presents a new approach for assessing/ranking the vulnerability of beaches to mean and extreme sea level rise at regional (island) scales. It combines socio-economic information with beach erosion projections from morphodynamic models to rank beach vulnerability in a structured, ‘holistic’ manner. It involves the collation of various beach geo-spatial environmental and socio-economic data, which are then combined with erosion projections under different climatic scenarios. A Strengths–Weaknesses–Opportunities–Threats (SWOT) framework is employed for the indicator selection, and multi-criteria methods (Analytical Hierarchy Process—AHP, Technique for Order of Preference by Similarity to Ideal Solution—TOPSIS, Preference Ranking Organization Method for Enrichment Evaluations—PROMETHEE II) are then used to optimize indicator weights and rank beach vulnerability. Framework implementation in Lesvos and Kos has shown that there will be significant effects of the mean and (particularly) of the extreme sea levels on the carrying capacity and the capability of the beaches to buffer backshore assets, in the absence of appropriate adaptation measures. As the proposed approach relies on widely available information on many of the socio-economic indicators required to assess the beach’s significance/criticality, it can provide a reproducible and transferable methodology that can be applied at different locations and spatial scales.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-01
DOI: 10.3390/jmse13030491
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 492: Multi-Objective Optimization for Artificial
Island Construction Scheduling Using Cooperative Differential Evolution
Authors: Tianju Zheng, Liping Sun, Jifeng Chen, Xinyuan Cui, Shuqi Li
First page: 492
Abstract: The construction of artificial islands is a complex engineering challenge requiring precise scheduling to optimize resource utilization, manage costs, ensure safety, and minimize environmental impacts in dynamic marine settings. In this paper, we present a multi-objective artificial island construction scheduling optimization model. This model considers many crucial factors that influence artificial island construction from 5 aspects: construction time, construction cost, project quality, resource utilization efficiency, and environmental impact. To optimize the proposed model, we propose an algorithm called Multi-objective Cooperative Differential Evolution (MOCDE). MOCDE integrates Cooperative Co-evolutionary Algorithms, and Differential Evolution to efficiently obtain the optimal schedules. To explore the performance of this model and the algorithm, extensive experiments are conducted based on real-world project data. Comparing MOCDE with established algorithms, results indicate that MOCDE improvements over previous SOTA models, achieving a reduction of 0.56% in Total Time, a decrease of 0.43% in Total Cost, and an enhancement of 7.38% in Total Quality. Besides, it also could adhere to ensure the environmental requirements.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-02
DOI: 10.3390/jmse13030492
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 493: Integration of Routine Core Data and
Petrographic Analyses to Determine the Sandstone Reservoir Flow Units in
the Bredasdorp Basin, Offshore South Africa
Authors: Nobathembu Tyhutyhani, Moses Magoba, Oswald Gwavava
First page: 493
Abstract: Routine core permeability and porosity are crucial in assessing flow units within a reservoir because they define a reservoir’s storage and flow capacities. A limited amount of work has been conducted on the lower cretaceous (Barremian to Valanginian) sandstones in the Bredasdorp Basin, offshore South Africa, focusing on the flow zones and the possible effect of diagenetic minerals on the individual flow zones, limiting understanding of reservoir quality and fluid flow behavior across the field. Nine hundred routine core analysis datasets were used to determine the flow units within the reservoir from three wells (F-A10, F-A13, and F-O2) from independent methods, namely: the Pore Throat Radius, Flow Zone Indicator, Stratigraphic Modified Lorenz Plot, and Improved Stratigraphic Modified Lorenz Plot. The results showed six flow units: fracture, super-conductive, conductor, semi-conductor, baffle, and semi-barrier. The super-conductive flow units contributed the most flow, whereas the semi-barrier and baffle units contributed the least flow. Petrography analyses revealed that the diagenetic minerals present were smectite, illite, glauconite, siderite, micrite calcite, and chlorite. The pore-filling minerals reduced the pore spaces and affected pore connectivity, significantly affecting the flow contribution of the baffle and semi-barrier units. Micrite calcite and siderite cementation in FU5 of F-A13 and FU9 of F-O2 significantly reduced the intergranular porosity by filling up the pore spaces, resulting in tight flow units with impervious reservoir quality. It was noted that where the flow unit was classified as super-conductive, authigenic clays did not significantly affect porosity and permeability as they only occurred locally. However, calcite and silica cementation significantly affected pore connectivity, where the flow unit was classified as a very low, tight, semi-barrier, or barrier.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-02
DOI: 10.3390/jmse13030493
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 494: Impact of Silted Coastal Port Engineering
Construction on Marine Dynamic Environment: A Case Study of Binhai Port
Authors: Xiaolong Deng, Zhifeng Wang, Xin Ma
First page: 494
Abstract: Siltation around the harbour entrance poses significant challenges to the navigational safety and operational stability of coastal ports. Previous research has predominantly focused on sedimentation mechanisms in sandy coastal environments, while studies on silt-muddy coasts remain scarce. This paper investigates the causes of siltation around the entrance of Binhai Port in Jiangsu Province, China, utilising field observation data and a two-dimensional tidal current numerical model, with emphasis on hydrodynamic variations and sediment dynamics. Observations reveal that tidal currents induce sediment deposition in the outer harbour entrance area, whereas pronounced scouring occurs near breakwater heads. During extreme weather events, such as Typhoons Lekima (2019) and Muifa (2022), combined wind–wave interactions markedly intensified sediment transport and accumulation, particularly amplifying siltation at the entrance, with deposition thicknesses reaching 0.5 m and 1.0 m, respectively. The study elucidates erosion–deposition patterns under combined tidal, wave, and wind forces, identifying two critical mechanisms: (1) net sediment transport directionality driven by tidal asymmetry, and (2) a lagged dynamic sedimentary response during sediment migration. Notably, the entrance zone, functioning as a critical conduit for water– sediment exchange, exhibits the highest siltation levels, forming a key bottleneck for navigational capacity. The insights gleaned from this study are instrumental in understanding the morphodynamic processes triggered by artificial structures in silt-muddy coastal systems, thereby providing a valuable reference point for the sustainable planning and management of ports.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-02
DOI: 10.3390/jmse13030494
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 495: A Case Study on the Corrosion of an Aging
Jack-Up Drilling Rig
Authors: Roohollah Babaei-Mahani, Sirous Yasseri, Wayne Lam, Pouyan Talebizadehsardari
First page: 495
Abstract: Corrosion costs the Oil & Gas Industry billions of pounds annually, primarily due to environmental factors such as high salinity, temperature fluctuations, and humidity in marine environments. Mobile Offshore Drilling Units (MODUs), especially jack-up rigs, are particularly susceptible to these dangers. This paper examines the impact of cold stacking on aging jack-up rigs and highlights how the absence of an adequate corrosion control system can accelerate structural deterioration. Our findings show that repair costs following cold stacking can far exceed the costs associated with maintaining rigs in a warm-stacked state. Preload tanks are critical areas prone to degradation due to microbiologically influenced corrosion (MIC) and inadequate preservation practices. Furthermore, although high-strength steels are frequently utilized in the construction of jack-up rigs due to their durability, we illustrate that, in the absence of meticulously devised preventative measures, these steels are susceptible to considerable corrosion, resulting in substantial repair expenses and diminished operational lifespans. This study highlights the significance of proactive corrosion control measures in maintaining the long-term structural integrity and cost-effectiveness of offshore drilling units.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-02
DOI: 10.3390/jmse13030495
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 496: Identification of Ship Maneuvering Behavior
Using Singular Value Decomposition-Based Hydrodynamic Variations
Authors: Cem Guzelbulut
First page: 496
Abstract: Recent efforts on the decarbonization, autonomy, and safety of the maritime vehicles required comprehensive analyses and prediction of the behavior of the existing vessels and prospective adaptations. To predict the performance of vessels, a better understanding of ship hydrodynamics is necessary. However, it is necessary to conduct dozens of experiments or computational fluid dynamics simulations to characterize the hydrodynamic behavior of the vessels, which require significant amounts of cost and time. Thus, system identification studies to characterize the hydrodynamics of ships have gained attention. The present study proposes a hybrid methodology that combines the existing hydrodynamic databases, and a prediction model of ship hydrodynamics based on motion indexes obtained by turning and zigzag tests. Firstly, singular value decomposition was applied to extract the main hydrodynamic variations, and an artificial yet realistic hydrodynamic behavior generation systematics was developed. Then, turning and zigzag tests were simulated to train artificial neural network models which predict how hydrodynamic behavior varies based on the motion indexes. Finally, the proposed methodology was applied to two vessels to predict the hydrodynamic behaviors of the target ships based on given motion indexes. It was found that the motion obtained via the predicted hydrodynamics showed a high correlation with the given motion indexes.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-03
DOI: 10.3390/jmse13030496
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 497: Study on the Flow Characteristics in a Large
Land-Based Circular Aquaculture Tank Based on Field Experiments
Authors: Yanfei Wu, Jianeng Chen, Chengxia Jia, Fukun Gui, Qixian Zhou, Dejun Feng, Qingjing Zhang
First page: 497
Abstract: The rapid expansion of large-scale aquaculture has created a demand for more efficient and sustainable farming systems. Among these, land-based circular tank aquaculture is emerging as a key solution due to its high efficiency, scalability, and effective waste management capabilities. Optimizing the hydrodynamic characteristics of these tanks is crucial for improving water quality management and ensuring the health of cultured fish. This study investigates the hydrodynamic characteristics of large land-based circular tanks, focusing on the effects of water pusher configurations and the presence of fish on flow dynamics and sewage collection efficiency. Field experiments were conducted under two conditions: with and without fish, while varying the pusher diameter, deployment angles, and the number of pushers. The flow characteristics at different layers of the tanks were measured using Acoustic Doppler Velocimetry. The results indicate that the pusher deployment has a more significant impact on the flow field and hydrodynamic characteristics compared with the pusher diameter. The optimal configuration for water circulation and sewage collection was identified when the pusher diameter was 11 cm, the deployment angle was 45°, and the number of pushers was 6. The presence of fish significantly influenced the flow field distribution by expanding high velocity flow zones. The findings provide a theoretical basis for optimizing water pusher deployment in large-scale circular tanks with fish, thereby contributing to improved water quality management and fish health.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-03
DOI: 10.3390/jmse13030497
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 498: Delayed Detached-Eddy Simulations of Aerodynamic
Variability During Carrier-Based Aircraft Landing with a Domain Precursor
Inflow Method
Authors: Jiawei Fu, Ruifan Hu, Hong Wang, Ke Xu, Shuling Tian
First page: 498
Abstract: Flight tests and wind tunnel experiments face difficulties in investigating the impact of aircraft carrier air-wake on the landing process. Meanwhile, numerical methods generally exhibit low overall computational efficiency in solving such problems. To address the computational challenges posed by the disparate spatiotemporal scales of the ship air-wake and aircraft motion, a domain precursor inflow method is developed to efficiently generate unsteady inflow boundary conditions from precomputed full-domain air-wake simulations. This study investigates the aerodynamic variability of carrier-based aircraft during landing through the turbulent air-wake generated by an aircraft carrier, employing a hybrid RANS-LES methodology on dynamic unstructured overset grids. The numerical framework integrates a delayed detached-eddy simulation (DDES) model with a parallel dynamic overset grid approach, enabling high-fidelity simulations of coupled aircraft carrier interactions. Validation confirms the accuracy of the precursor inflow method in reproducing air-wake characteristics and aerodynamic loads compared to full-domain simulations. Parametric analyses of 15 distinct landing trajectories reveal significant aerodynamic variability, particularly within 250 m of the carrier, where interactions with island-generated vortices induce fluctuations in lift (up to 25%), drag (18%), and pitching moments (30%). Ground effects near the deck further amplify load variations, while lateral deviations in landing paths generate asymmetric forces and moments. The proposed methodology demonstrates computational efficiency for multi-scenario analysis, providing critical insights into aerodynamic uncertainties during carrier operations.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-03
DOI: 10.3390/jmse13030498
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 499: Study on the Reconstruction of the Spectral
Pattern of Near-Island Reef Bimodal Waves
Authors: Weihang Sun, Yuguo Pei, Leilei Qu, Xiaobo Wang
First page: 499
Abstract: Accurately fitting bimodal wave spectra is crucial for understanding complex ocean conditions and promoting ocean-related research. In this context, this paper aims to solve the problem of reconstructing bimodal wave spectra in domestic island and reef areas. Taking measured data from the Jiangsu Xiangshui station in August 2017 and the Xisha Sea area on 1–3 August 2014 as case studies, the researchers selected three types of original bimodal wave spectra. After obtaining the sample spectra through fast Fourier transform and wave spectrum non-dimensionalization, this paper selected a novel wave spectrum—the rational fractional unimodal spectrum—and two classical wave spectra—the Jonswap spectrum and the Neumann spectrum. Three bimodal wave spectra were constructed by superimposing the low-frequency sub-spectrum and the high-frequency sub-spectrum. After using the improved PSO algorithm to optimize the parameters of these three bimodal wave spectra, the specific parameters were obtained. Comparisons were made between the above three bimodal wave spectra and three high-precision double-peak fitting spectra, the Huang Peiji six-parameter spectrum, the Ochi-Hubble spectrum, and the Shen Zhichun fitting spectrum, and the fitting effects were analyzed. The results demonstrated that when fitting the bimodal spectrum dominated by wind waves and the bimodal spectrum with comparable wind and swell energy, the combination of the rational fractional unimodal spectrum and the Neumann spectrum can achieve a fitting accuracy of up to 99%. When fitting the bimodal spectrum dominated by swell waves, the combination of the rational fractional unimodal spectrum and the Jonswap spectrum can also achieve a fitting accuracy of 99%. The findings of this paper provide valuable references for the study of other types of double-peak wave spectra in China.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-03
DOI: 10.3390/jmse13030499
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 500: Accelerated Life Testing of Marine Electrical
Insulation Systems Based on Frequency-Dependent Breakdown Analysis
Authors: Hyeun-Chul Kim
First page: 500
Abstract: Marine power systems, including generators and transformers, experience voltage stress at various frequencies. Once the stress exceeds the bearing capacity of the electrical system, it results in insulation breakdown or failure. Therefore, extensive testing is required to ensure that marine electrical insulation systems are reliable. In accordance with International Electrotechnical Commission (IEC) standards, conventional tests at commercial frequencies require over 5000 h, making them time-consuming, inefficient, and practically infeasible. This study explores frequency-based accelerated life testing to reduce the duration of testing. Insulation systems made of mica-based corona-resistant materials and epoxy resin were tested at 60, 300, 600, and 900 Hz using a variable-frequency high-voltage tester. The results show that the time to failure decreases as the frequency increases (from 381.83 h at 60 Hz to 22.33 h at 900 Hz, a 94% reduction). Power and exponential decay models effectively describe this relationship. The power model provides a better overall fit, and the exponential decay model improves the accuracy at higher frequencies. This study confirms that higher frequencies accelerate insulation degradation, shortening test times considerably. Frequency-based accelerated testing can enhance insulation system evaluation and optimize international testing standards.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-04
DOI: 10.3390/jmse13030500
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 501: Marine Renewable Energy Resources in Peru: A
Sustainable Blue Energy for Explore and Develop
Authors: Carlos Cacciuttolo, Giovene Perez, Mivael Falcón
First page: 501
Abstract: The Peruvian coast covers more than 3000 km along the Pacific Ocean, being one of the richest seas in terms of biodiversity, productivity, fishing, and renewable energy potential. Marine renewable energy (MRE) in both offshore and coastal environments of Peru is, currently, a huge reserve of practically unused renewable energy, with inexhaustible potential. In this context, renewable energies from hydroelectric, biomass, wind, and solar sources have been applied in the country, but geothermal, waves, tidal currents, and tidal range sources are currently underdeveloped. This article presents the enormous source of sustainable blue energy for generating electrical energy that exists in Peru from waves and tidal resource potential. In addition, this article presents the main opportunities, gaps, and key issues for the implementation of marine renewable energy (MRE), with emphasis on: (i) showing the available potential in the northern, central, and southern Pacific Ocean territories of Peru, (ii) characterizing the marine energy best available technologies to implement, (iii) the environmental and socio-economic impacts of marine renewable energy, and (iv) discussion of challenges, opportunities, and future directions for developments in the marine energy sector. Finally, the article concludes that the greatest possibilities for exploiting the abundant marine renewable energy (MRE) resource in Peru are large spaces in both offshore and coastal environments on the Pacific Ocean that can be considered for harvesting energy. These issues will depend strongly on the implementation of regulations and policies for the strategic use for planning of marine resources, encouraging research and development (R&D) for creating sustainable innovations, incentives for project finance mechanisms, and developing specialized local human capital, considering the sustainability of livelihoods of coastal communities and ecosystems.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-04
DOI: 10.3390/jmse13030501
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 502: Development and Application of Evaluation
Procedure for Performance Testing of Vacuum Suction Pad in Automatic
Mooring System in a Lab Test
Authors: Jeongnam Kim, Jaehyeon An, Youngki Kim, Youhee Cho
First page: 502
Abstract: The fourth Industrial Revolution is driving the maritime and port logistics industry toward greater operational efficiency and reduced human intervention through automatic mooring systems. This study developed and applied a lab-based evaluation procedure to assess the performance and stability of vacuum suction pads in such systems. Test conditions were based on Cavotec’s specifications, with evaluation criteria tailored to the pads’ required performance. Relevant standards were reviewed to establish a vacuum pressure leakage criterion of 5% or less. Results showed that the pads maintained pressure reductions below this threshold, confirming their suitability for automatic mooring, though dynamic factors like heave and tides remain untested.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-04
DOI: 10.3390/jmse13030502
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 503: Research on Maneuvering Motion Prediction for
Intelligent Ships Based on LSTM-Multi-Head Attention Model
Authors: Dongyu Liu, Xiaopeng Gao, Cong Huo, Wentao Su
First page: 503
Abstract: In complex marine environments, accurate prediction of maneuvering motion is crucial for the precise control of intelligent ships. This study aims to enhance the predictive capabilities of maneuvering motion for intelligent ships in such environments. We propose a novel maneuvering motion prediction method based on Long Short-Term Memory (LSTM) and Multi-Head Attention Mechanisms (MHAM). To construct a foundational dataset, we integrate Computational Fluid Dynamics (CFD) numerical simulation technology to develop a mathematical model of actual ship maneuvering motions influenced by wind, waves, and currents. We simulate typical operating conditions to acquire relevant data. To emulate real marine environmental noise and data loss phenomena, we introduce Ornstein–Uhlenbeck (OU) noise and random occlusion noise into the data and apply the MaxAbsScaler method for dataset normalization. Subsequently, we develop a black-box model for intelligent ship maneuvering motion prediction based on LSTM networks and Multi-Head Attention Mechanisms. We conduct a comprehensive analysis and discussion of the model structure and hyperparameters, iteratively optimize the model, and compare the optimized model with standalone LSTM and MHAM approaches. Finally, we perform generalization testing on the optimized motion prediction model using test sets for zigzag and turning conditions. The results demonstrate that our proposed model significantly improves the accuracy of ship maneuvering predictions compared to standalone LSTM and MHAM algorithms and exhibits superior generalization performance.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-05
DOI: 10.3390/jmse13030503
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 504: Collision Characteristics During Autonomous
Underwater Vehicle Recovery with a Petal Mechanical Gripper
Authors: Deyong Bian, Yuhong Liu, Manxing Yuan, Hongwei Zhang
First page: 504
Abstract: Efficient underwater recovery systems are essential for battery recharging and data exchange of autonomous underwater vehicles (AUVs). This paper introduced a petal mechanical gripper (PMG) for AUV underwater recovery, and investigated the collision characteristics between the AUV and PMG during the recovery. A collision model was developed with Adams software 2018 to investigate the effect of the recovery mode and closure speed of a PMG driving claw on the recovery efficiency and AUV motion behaviors. A tank experiment was performed to validate the collision model. The simulation results indicated that the active recovery mode had a higher efficiency. Moreover, optimizing the PMG closure speed significantly reduced the recovery time and improved the AUV motion stability. This study provides valuable theoretical guidance for the effective recovery of underwater vehicles.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-05
DOI: 10.3390/jmse13030504
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 505: Architecture and Genesis of Submarine Migrating
Channel–Levee Systems in the Pearl River Mouth Basin, Northern South
China Sea
Authors: Zenggui Kuang, Zijian Zhang, Jinfeng Ren, Wei Deng
First page: 505
Abstract: Seismic data reveal that the shelf edge of the Pearl River Mouth Basin in the northern South China Sea is characterized by slope channels that have consistently migrated in a north-easterly direction over millions of years. Previous research suggests that the channel migration is driven by the interplay between along-slope bottom currents and downslope turbidity currents. Here, we propose an alternative interpretation, suggesting the migrating channels are actually a series of channel–levee systems and the migration is driven by their own evolution of erosion–deposition under the influence of the Coriolis force. A detailed interpretation of high-resolution seismic data reveals seven types of architectural elements, characteristic of channel–levee systems, which are erosional bases, outer levees, inner levees, channel-axis fills, marginal slumps, drapes, and lobes. An analysis of the sequence stratigraphy and stacking pattern of channels suggests that channel migration from the middle Miocene to the present is discontinuous with at least three regional discontinuities within the channel migration sequence marked by regional drapes. Down-dipping reflections along the margin of channels, previously interpreted as bottom-currents deposits, are here reinterpreted as mass-transport processes along steep channel walls. The migration is most prominent in the middle reach, where erosion and deposition coexist and dominate alternately in two different phases. During the long-term canyon-filling turbidity currents prevailing phase, deposition dominates, leading to the development of a prominent asymmetric right-hand (west) inner levee due to the Coriolis force. In contrast, during the canyon-flushing turbidity currents prevailing phase, erosion dominates and the preferred right-hand (west) inner levee enforces the flow to erode eastward, then drives the channel migrating eastward. The alternating effects of erosion and deposition ultimately result in unidirectional channel migration.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-05
DOI: 10.3390/jmse13030505
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 506: Fatigue Reliability Analysis of Offshore Wind
Turbines Under Combined Wind–Wave Excitation via Direct Probability
Integral Method
Authors: Jingyi Ding, Hanshu Chen, Xiaoting Liu, Youssef F. Rashed, Zhuojia Fu
First page: 506
Abstract: As offshore wind turbines develop into deepwater operations, accurately quantifying the impact of stochastic excitation in complex sea environments on offshore wind turbines and conducting structural fatigue reliability analysis has become challenging. In this paper, based on long-term wind–wave reanalysis data from the South China Sea, a novel direct probability integral method (DPIM) is developed for the stochastic response and fatigue reliability analysis of the key components for the floating offshore wind turbine structures, under combined wind–wave excitation. A 5 MW floating offshore wind turbine is considered as the research object, and a comprehensive analysis of the wind turbine system is performed to assess the short-term fatigue damage at the tower base and blade root. The proposed method’s accuracy and efficiency are validated by comparing the results to those obtained from Monte Carlo simulations (MCS) and a subset simulation (SSM). Additionally, a sensitivity analysis is conducted to evaluate the impact of different environmental parameters on fatigue damage, providing valuable insights for the design and operation of FOWTs in varying sea conditions. Furthermore, the results indicate that the fatigue life of floating offshore wind turbine (FOWT) structures under combined wind–wave excitation meets the design requirements. Notably, the fatigue reliability of the wind turbine under aligned wind–wave conditions is lower compared to misaligned wind–wave conditions.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-05
DOI: 10.3390/jmse13030506
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 507: Enhanced Seafloor Topography Inversion Using an
Attention Channel 1D Convolutional Network Based on Multiparameter Gravity
Data: Case Study of the Mariana Trench
Authors: Qiang Wang, Ziyin Wu, Zhaocai Wu, Mingwei Wang, Dineng Zhao, Taoyong Jin, Qile Zhao, Xiaoming Qin, Yang Liu, Yifan Jiang, Puchen Zhao, Ning Zhang
First page: 507
Abstract: Seafloor topography data are fundamental for marine resource development, oceanographic research, and maritime rights protection. However, approximately 75% of the ocean remains unsurveyed for bathymetry. Sole reliance on shipborne measurements is insufficient for constructing a global bathymetric model within a short timeframe; consequently, satellite altimetry-based inversion techniques are essential for filling data gaps. Recent advancements have improved the variety and quality of satellite altimetry gravity data. To leverage the complementary advantages of multiparameter gravity data, we propose a 1D convolutional neural network based on a convolutional attention module, termed the Attention Channel 1D Convolutional Network (AC1D). Results of a case study of the Mariana Trench indicated that the AC1D grid predictions exhibited improved agreement with single-beam depth checkpoints, with standard deviation reductions of 6.32%, 20.79%, and 36.77% and root mean square error reductions of 7.11%, 22.82%, and 50.99% compared with those of parallel linked backpropagation, the gravity–geological method, and a convolutional neural network, respectively. The AC1D grid demonstrated enhanced stability in multibeam bathymetric validation metrics and exhibited better consistency with multibeam bathymetry data and the GEBCO2023 grid. Power spectral density analysis revealed that AC1D effectively captured rich topographic signals when predicting terrain features with wavelengths below 6.33 km.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-05
DOI: 10.3390/jmse13030507
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 508: Retrieving Palaeoecological Information from
Historic Fossil Finds: A Taphonomic Cold Case from Orciano Pisano (Central
Italy) Reveals a Distinctive Trophic Interaction in the Pliocene
Mediterranean Sea
Authors: Edoardo Terranova, Giovanni Bianucci, Marco Merella, Chiara Sorbini, Alberto Collareta
First page: 508
Abstract: Evidence of trophic interactions between sharks and cetaceans is rather widespread in the fossil records, consisting as it does of tooth marks on bones and rarer teeth or tooth fragments embedded in (or associated with) skeletal remains. Here, we reappraise a partial mysticete (baleen whale) forelimb that was collected more than a century ago from Pliocene deposits exposed at the celebrated fossil locality of Orciano Pisano (Tuscany, central Italy). This specimen, which is revealed to originate from an early juvenile individual, features shark tooth marks on both the humerus and radius. Whether these traces are due to active predation or to scavenging cannot be ascertained. During the Pliocene, the Mediterranean Basin was inhabited by a diverse elasmobranch fauna, including a number of mammal-eating forms that no longer inhabit the Mediterranean Sea (e.g., Galeocerdo and some Carcharhinus spp. as well as the extinct Parotodus). Early juvenile mysticetes were also likely more common than today in the Pliocene Mediterranean Sea, which may have contained balaenid and balaenopterid calving grounds, thus providing the Mediterranean mammal-eating sharks with vulnerable, energetically valuable potential prey items. Thus, our results evoke a kind of trophic interaction that was likely common and ecologically relevant in the Pliocene Mediterranean Sea.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-05
DOI: 10.3390/jmse13030508
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 509: Towards a Common Language for Mainstreaming
Nature-Based Solutions Through Coastal Systems in the North Sea Region:
The Manabas Coast Project
Authors: Geert J. M. van der Meulen, Jurre J. de Vries, Lisa van Well, Frances A. Kannekens
First page: 509
Abstract: Nature-based solutions (NBSs) offer an opportunity to address environmental and societal challenges worldwide while simultaneously providing benefits for human well-being as well as biodiversity. Despite a growing demand and evidence base for NBSs in coastal systems, the scaling of their implementation and mainstreaming of their principles in policy and practice are constrained by multiple barriers, such as misinterpretations of concepts, effectiveness, or locked-in preferences or conventions of traditional solutions. To address these constraints, an international consortium of coastal authorities and experts in the North Sea Region collaborates to validate, document, and share learnings of NBSs to establish a framework for mainstreaming NBSs for flood and coastal erosion risk management around the North Sea. Co-creation processes of workshops, field visits, and expert knowledge sessions contributed to a theoretical framework and baseline assessments of exemplary sandy and muddy case study sites in the region, amongst others, iteratively providing and showcasing building blocks for the mainstreaming framework. This article takes stock halfway of the project’s activities, learnings, and status of the called-for common language.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-05
DOI: 10.3390/jmse13030509
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 510: Energy Saving in Ship Central Cooling Systems:
IMC-Tuned PID with Feedforward Control
Authors: Tae-Youl Jeon, Young-Chan Lee
First page: 510
Abstract: This study examines the energy savings in a ship’s central cooling system using feedforward control with IMC (Internal Model Control)-based PID tuning. A central cooling system is essential for maintaining the temperature of the engine and other major machinery, thereby improving the overall energy efficiency. The seawater pump in the central cooling system consumes a relatively large amount of power, which makes efficient operation essential. This study compared the power consumption of variable-speed seawater pumps based on actual operational data from a ship. By incorporating a feedforward PI controller into the IMC-based PI-PID controller combinations, this study simulated energy savings. The results indicate that the proposed controller combined with the feedforward PI controller reduces the power consumption of seawater pumps compared with conventional methods. Simulation tests were conducted using approximately 11 days of operational data to verify the effectiveness of the proposed control strategy in achieving energy savings. The proposed controller combination saves approximately 277.4 kWh of power over 11 days compared to conventional control methods.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-05
DOI: 10.3390/jmse13030510
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 511: Numerical Simulation of Natural Gas Hydrate
Depressurization Extraction Considering Phase Transition Characteristics
Authors: Qiang Fu, Mingqiang Chen, Weixin Pang, Lirong Dong
First page: 511
Abstract: Natural gas hydrate (NGH) is a clean resource characterized by abundant potential reserves, clean combustion, and high energy density. Although significant progress has been made in the development of NGH resources all around the world, challenges still exist that hinder commercial exploitation, such as a low daily gas production rate and short steady production periods. One significant reason lies in the complex gas–liquid–solid phase transitions occurring within the formation during production, which lead to changes in flow capacity. Understanding the phase change mechanism of NGH reservoirs will help to further reveal the production increase mechanism. To address the phase transitions’ effect on production, this paper establishes a numerical simulation model for the depressurization exploitation of natural gas hydrates in order to investigate phase transition characteristics at the field scale. First, the phase equilibrium calculation method is presented and the phase equilibrium curve is modified by considering the capillary effect, soluble salt, and surface adsorption. Then, the phase transition model is successfully characterized in a simulation and the numerical simulation model is established based on the first test project parameters in the Shenhu area. The production characteristics of different sediment types (montmorillonite, South China Sea sediments, kaolin, and silt) are analyzed under the effects of water content and salinity. It is shown that lower initial water content and higher salinity result in higher gas production. The results provide a better understanding of the effects of phase transition parameters on NGH production at the field scale.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-05
DOI: 10.3390/jmse13030511
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 512: Gastrointestinal Helminthofauna of Mediterranean
Elasmobranchs
Authors: Perla Tedesco, Enrico Liborio Quadrone, Linda Albonetti, Federica Marcer, Monica Caffara, Maria Letizia Fioravanti, Fausto Tinti, Andrea Gustinelli
First page: 512
Abstract: Elasmobranchs (Chondrichthyes, Elasmobranchii) are exposed to a variety of gastrointestinal parasites acquired through the ingestion of infected prey. An increasing amount of evidence suggests the usefulness of parasitological information to elucidate aspects of the biology and ecology of sharks and rays, to inform the correct management and conservation of their stocks and the appropriate husbandry of captive specimens. This study aims to identify at the morphological and molecular level the helminth parasites found in the stomachs and intestines of various elasmobranchs accidentally caught by Mediterranean fisheries, with the aim of updating and providing new information on the parasitic fauna of these species. Specimens of smooth-hound Mustelus mustelus, blackspotted smooth-hound Mustelus punctulatus, blue shark Prionace glauca, spiny dogfish Squalus acanthias, lesser-spotted dogfish Scyliorhinus canicula, pelagic stingray Pteroplatytrygon violacea and Mediterranean starry ray Raja asterias were examined. The parasitological examination allowed us to identify the nematode Acanthocheilus rotundatus in the two species of smooth-hounds analyzed, the tapeworm species Scyphophyllidium exiguum, S. prionacis, Anthobothrium caseyi and Nybelinia indica in P. glauca, the nematodes Hysterothylacium aduncum and Proleptus obtusus in S. acanthias and S. canicula, respectively, and finally the nematode Pseudanisakis rajae and the tapeworm Nybelinia sp. in Raja asterias. Some observations represent new reports at a geographical level, in particular, those on A. caseyi in P. glauca and H. aduncum in S. acanthias from the Adriatic Sea, or first host records, such as S. exiguum and N. indica in P. glauca or P. rajae. in R. asterias. The results of this survey represent a contribution to broadening the knowledge of the parasitic fauna of these elasmobranchs in the Mediterranean Sea. From more in-depth future studies, it will be possible to reach more solid evidence and general conclusions on aspects relating to the biology, ecology, and health of the investigated species, offering useful information for their conservation and management.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-05
DOI: 10.3390/jmse13030512
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 513: Study on the Effects of Internal Building
Layouts on Tsunami-Driven Single-Container Motion
Authors: Yudou Hou, Tomoaki Nakamura, Yong-Hwan Cho, Norimi Mizutani
First page: 513
Abstract: This study investigated the complex interactions among tsunamis, debris, and coastal building structures under extreme hydrodynamic conditions. We performed numerical simulations to explore the influence of varying wave conditions, debris, and building designs to identify the most vulnerable parts of a building structure. The three-dimensional coupled fluid–structure–sediment–seabed interaction model (FS3M) was employed to simulate these interactions and validated against physical experimental data to ensure accuracy. The results revealed that debris significantly altered the wave impact dynamics, increasing the force exerted on buildings regardless of their structural features. This study provides relevant insights into the effectiveness of different building layouts in mitigating damage, highlighting the critical role of buildings with internal walls perpendicular to the wave direction, which significantly mitigated the tsunami’s impact at specific regions.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-06
DOI: 10.3390/jmse13030513
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 514: Adaptive Temporal Reinforcement Learning for
Mapping Complex Maritime Environmental State Spaces in Autonomous Ship
Navigation
Authors: Ruolan Zhang, Xinyu Qin, Mingyang Pan, Shaoxi Li, Helong Shen
First page: 514
Abstract: The autonomous decision-making model for ship navigation requires extensive interaction and trial-and-error in real, complex environments to ensure optimal decision-making performance and efficiency across various scenarios. However, existing approaches still encounter significant challenges in addressing the temporal features of state space and tackling complex dynamic collision avoidance tasks, primarily due to factors such as environmental uncertainty, the high dimensionality of the state space, and limited decision robustness. This paper proposes an adaptive temporal decision-making model based on reinforcement learning, which utilizes Long Short-Term Memory (LSTM) networks to capture temporal features of the state space. The model integrates an enhanced Proximal Policy Optimization (PPO) algorithm for efficient policy iteration optimization. Additionally, a simulation training environment is constructed, incorporating multi-factor coupled physical properties and ship dynamics equations. The environment maps variables such as wind speed, current velocity, and wave height, along with dynamic ship parameters, while considering the International Regulations for Preventing Collisions at Sea (COLREGs) in training the autonomous navigation decision-making model. Experimental results demonstrate that, compared to other neural network-based reinforcement learning methods, the proposed model excels in environmental adaptability, collision avoidance success rate, navigation stability, and trajectory optimization. The model’s decision resilience and state-space mapping align with real-world navigation scenarios, significantly improving the autonomous decision-making capability of ships in dynamic sea conditions and providing critical support for the advancement of intelligent shipping.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-06
DOI: 10.3390/jmse13030514
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 515: Dynamic Structural Behavior of Monopile Support
Structure for 15 MW Offshore Wind Turbine During Different Phases of
Operation
Authors: Sajid Ali, Muhammad Waleed, Daeyong Lee
First page: 515
Abstract: The structural integrity of offshore wind turbine monopiles is critical for ensuring operational stability and long-term performance under varying environmental and aerodynamic loads. However, transient load conditions during different operational phases, such as start, normal stop, and emergency stop, can significantly impact structural behavior, influencing fatigue life and dynamic stability. This study investigates the dynamic structural response of a 15 MW offshore wind turbine monopile, incorporating modal analysis and transient simulations to assess deflection, forces, moments, and rotational displacements at the mud-line. The modal analysis revealed natural frequencies of 0.509492 Hz, 1.51616 Hz, and 3.078425 Hz for the blade’s flap-wise modes, while side-to-side modes for the combined tower and monopile structure were identified at 0.17593 Hz, 0.922308 Hz, and 1.650862 Hz. These frequencies are crucial in evaluating resonance risks and ensuring dynamic stability under combined aerodynamic and hydrodynamic forces. The transient analysis demonstrated that lateral force (Fy) variations peaked at −2500 kN during emergency stop, while moment fluctuations (My) reached ±100,000 kNm, reflecting the monopile’s high dynamic sensitivity under sudden aerodynamic unloading. Rotational displacements also showed significant variations, with θx oscillating up to ±0.0009 degrees and θy between −0.0022 and −0.0027 degrees. These findings provide valuable insights into optimizing monopile design to mitigate resonance effects, improve fatigue performance, and enhance structural resilience for large-scale offshore wind turbine support systems.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-06
DOI: 10.3390/jmse13030515
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 516: The Integration of a Medium-Resolution
Underwater Radioactivity System in the COSYNA Observing System at
Helgoland Island, Germany
Authors: Christos Tsabaris, Stylianos Alexakis, Miriam Lienkämper, Max Schwanitz, Markus Brand, Manolis Ntoumas, Dionisis L. Patiris, Effrosyni G. Androulakaki, Philipp Fischer
First page: 516
Abstract: The continuous monitoring of radioactivity in a cabled subsea network in the North Sea Observatory was performed to test the performance of a medium-resolution underwater spectrometer, as well as to identify and to assess potential anthropogenic and/or natural hazards. The effectiveness of continuous monitoring was tested together with the operability of the underwater sensor, and quantification methods were optimized to identify the type of radioactivity as well as the activity concentration of radionuclides in the seawater. In the frame of the RADCONNECT project, a medium-resolution underwater radioactivity system named GeoMAREA was integrated into an existing cabled ocean observatory placed on Helgoland Island (COSYNA network). The system could be operated via an online mode controlled by the operational centre (AWI), as well as remotely by the end-user (HCMR). The system provided gamma-ray spectra and activity concentrations of key radionuclides that were enriched in seawater during the monitoring period. As concerns the quantification method of natural radioactivity, the average activity concentrations (in terms of the total monitoring period) of 214Bi, 208Tl, 228Ac and 40K were found to be 108 ± 30, 57 ± 14, 40 ± 5 and 9800 ± 500 Bqm−3, respectively. As concerns the quantification of 137Cs, the average activity concentration in terms of the total monitoring period (although it is uncertain) was found to be 6 ± 4 Bqm−3. The data analysis proved that the system had a stable operation in terms of voltage stability, so all acquired spectra could be summed up efficiently in time to produce statistically optimal gamma-ray spectra for further analysis.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-06
DOI: 10.3390/jmse13030516
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 517: A Reef’s High-Frequency Soundscape and the
Effect on Telemetry Efforts: A Biotic and Abiotic Balance
Authors: Frank McQuarrie, C. Brock Woodson, Catherine R. Edwards
First page: 517
Abstract: Acoustic telemetry is a tool for tracking animals, but transmitted signals from tagged animals are not always detected. Detection efficiency declines with increasing background noise, which can have both abiotic and biotic sources. The abiotic noise present in reef environments (waves, bubbles, etc.) is primarily low-frequency, but snapping shrimp create high-frequency noise that can interfere with transmission detections. Prior work in shallow coastal reefs correlated winds with less high-frequency background noise, and hypothesized that it was due to a balance of biotic and/or abiotic factors: shrimp may be less active during high wind events, and sound attenuation at the surface increases with wave height. To test this hypothesis, passive acoustic recordings from a live-bottom reef are used to quantify snapping shrimp snap rate. Snap rate was strongly correlated with temperature, and warmer environments appeared to be challenging for acoustic telemetry. However, the majority of synoptic variability in noise is shown to be driven by abiotic attenuation. Wind speed has little to no effect on snapping shrimp behavior, but has a significant inverse correlation with high-frequency noise levels due to surface attenuation of high-frequency noise, and therefore a positive effect on detection efficiency, pointing to primarily abiotic forcing behind noise variability and resulting telemetry success. This research gives context to previously collected detection data and can be leveraged to help plan future acoustic arrays in shallow, complex, and/or noisy environments, potentially predicting changes in detection range.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-07
DOI: 10.3390/jmse13030517
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 518: ShipNetSim: An Open-Source Simulator for
Real-Time Energy Consumption and Emission Analysis in Large-Scale Maritime
Networks
Authors: Ahmed Aredah, Hesham A. Rakha
First page: 518
Abstract: The imperative of decarbonization in maritime shipping is underscored by the sector’s sizeable contribution to worldwide greenhouse gas emissions. ShipNetSim, an open-source multi-ship simulator created in this study, combines state-of-the-art hydrodynamic modeling, dynamic ship-following techniques, real-time environmental data, and cybersecurity threat simulation to quantify and evaluate marine fuel consumption and CO2 emissions. ShipNetSim uses well-validated approaches, such as the Holtrop resistance and B-Series propeller analysis with a ship-following model inspired by traffic flow theory, augmented with a novel module simulating cyber threats (e.g., GPS spoofing) to evaluate operational efficiency and resilience. In a case study simulation of the journey of an S175 container vessel from Savannah to Algeciras, the simulator estimated the total fuel consumption to be 478 tons of heavy fuel oil and approximately 1495 tons of CO2 emissions for a trip of 7 days and 15 h within 13.1% of reported operational estimates. A twelve-month sensitivity analysis revealed a marginal 1.5% range of fuel consumption variation, demonstrating limiting variability for different environmental conditions. ShipNetSim not only yields realistic predictions of energy consumption and emissions but is also demonstrated to be a credible framework for the evaluation of operational scenarios—including speed adjustment, optimized routing, and alternative fuel strategies—that directly contribute to reducing the marine carbon footprint. This capability supports industry stakeholders and policymakers in achieving compliance with global decarbonization targets, such as those established by the International Maritime Organization (IMO).
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-08
DOI: 10.3390/jmse13030518
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 519: Ship Contour: A Novel Ship Instance Segmentation
Method Using Deep Snake and Attention Mechanism
Authors: Chen Chen, Songtao Hu, Feng Ma, Jie Sun, Tao Lu, Bing Wu
First page: 519
Abstract: Ship instance segmentation technologies enable the identification of ship targets and their contours, serving as an auxiliary tool for monitoring, tracking, and providing critical support for maritime and port safety management. However, due to the different shapes and sizes of ships, as well as the complexity and fluctuation of lighting and weather, existing ship instance segmentation approaches frequently struggle to accomplish correct contour segmentation. To address this issue, this paper introduces Ship Contour, a real-time segmentation method for ship instances based on contours that detects ship targets using an improved CenterNet algorithm. This method utilizes DLA-60 (deep layer aggregation) as the core network to ensure detection accuracy and speed, and it integrates an efficient channel attention (ECA) mechanism to boost feature extraction capability. Furthermore, a Mish activation function replaces ReLU to better adapt deep network learning. These improvements to CenterNet enhance model robustness and effectively reduce missed and false detection. In response to the issue of low accuracy in extracting ship target edge contours using the original deep snake end-to-end method, a scale- and translation-invariant normalization scheme is employed to enhance contour quality. To validate the effectiveness of the proposed method, this research builds a dedicated dataset with up to 2300 images. Experiments demonstrate that this method achieves competitive performance, with an accuracy rate of AP0.5:0.95 reaching 63.6% and a recall rate of AR0.5:0.95 reaching 67.4%.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-08
DOI: 10.3390/jmse13030519
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 520: Sediment Provenance and Facies Analysis of the
Huagang Formation in the Y-Area of the Central Anticlinal Zone, Xihu Sag,
East China Sea
Authors: Xiao Ma, Wei Yan, Yi Yang, Ru Sun, Yue Chao, Guoqing Zhang, Chao Yang, Shudi Zhang, Dapeng Su, Guangxue Zhang, Hong Xu
First page: 520
Abstract: Recent breakthrough exploration wells in the Huagang Formation in the Y-area of the central anticlinal zone of the Xihu Sag have confirmed the significant exploration potential of structure–lithology complex hydrocarbon reservoirs. However, limited understanding of the provenance system, sedimentary facies, and microfacies has hindered further progress in complex hydrocarbon exploration. Analysis of high-precision stratigraphic sequences and seismic facies data, mudstone core color, grain-size probability cumulative curves, core facies, well logging facies, lithic type, the heavy-mineral ZTR index, and conglomerate combinations in drilling sands reveals characteristics of the source sink system and provenance direction. The Huagang Formation in the Y-area represents an overall continental fluvial delta sedimentary system that evolved from a braided river delta front deposit into a meandering river channel large-scale river deposit. The results indicate that the primary provenance of the Huagang Formation in the Y-area of the Xihu Sag is the long-axis provenance of the Hupi Reef bulge in the northeast, with supplementary input from the short-axis provenance of the western reef bulge. Geochemical analysis of wells F1, F3, and G in the study area suggests that the prevailing sedimentary environment during the period under investigation was characterized by anoxic conditions in nearshore shallow waters. This confirms previous research indicating strong tectonic reversal in the northeast and a small thickness of the central sand body unrelated to the flank slope provenance system. The aforementioned findings deviate from conventional understanding and will serve as a valuable point of reference for future breakthroughs in exploration.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-09
DOI: 10.3390/jmse13030520
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 521: Study on the Dynamic Characteristics of Floating
Production Storage and Offloading Units and Steel Catenary Risers Under
the Action of Internal Solitary Waves
Authors: Fengming Du, Mingjie Li, Zetian Mi, Pan Gao
First page: 521
Abstract: In the ocean, internal solitary waves (ISW) pose a serious threat to the safety of marine engineering structures such as floating production storage and offloading (FPSO) units and steel catenary risers (SCRs). In this work, a calculation method for the load acting on an FPSO by internal solitary waves and a calculation method for the cable recovery force were proposed, the motion characteristics of the FPSO under the action of internal solitary waves were analyzed, and the dynamic characteristics of SRCs were further studied. The results show that that the internal solitary wave load reaches its maximum value before the ISW reaches the FPSO position, and the displacement reaches its maximum value around the time when the ISW reaches the FPSO position. The smaller the horizontal pre-tension of the mooring cable, the greater the displacement of the FPSO. The stress of the SRC reaches its maximum value when the FPSO reaches its maximum displacement, while it reaches its minimum value when the FPSO reaches its minimum motion. As the incident angle of the ISW increases, the stress of the SCRs slightly decreases. This model and the findings can provide a technical support and guidance for the design of FPSOs and SCRs.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-09
DOI: 10.3390/jmse13030521
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 522: Design of Encoding Algorithm for Underwater
Wireless Optical Communication Based on Spinal Code
Authors: Xiaoyang Yu, Min Yu, Yun Zhou, Tianwei Chen
First page: 522
Abstract: The marine environment is complex and variable, with the absorption and scattering effects of seawater and turbulence causing significant attenuation of received optical signals and introducing random jitter, which limits the communication range and stability of underwater wireless optical communication systems. This paper presents the Superposition UEP-Spinal Code structure, which utilizes unequal error protection (UEP) to adjust the transmission performance of different types of information in underwater composite data communication by adjusting the superposition weighting factors in the encoding algorithm. This encoding method enhances the noise immunity of important data, and with the same bandwidth utilization, the overall decoding complexity is reduced by 13.3% compared to the previously improved Spinal code encoding algorithm. The results show that the Superposition UEP-Spinal Code provides a more stable, reliable, and efficient communication solution for underwater wireless optical communication systems with randomly varying channel conditions.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-09
DOI: 10.3390/jmse13030522
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 523: Risk Assessment of Hydrogen Fuel System Leakage
in Ships Based on Noisy-OR Gate Model Bayesian Network
Authors: Gen Li, Haidong Zhang, Shibo Li, Chunchang Zhang
First page: 523
Abstract: To mitigate the risk of hydrogen leakage in ship fuel systems powered by internal combustion engines, a Bayesian network model was developed to evaluate the risk of hydrogen fuel leakage. In conjunction with the Bow-tie model, fuzzy set theory, and the Noisy-OR Gate model, an in-depth analysis was also conducted to examine both the causal factors and potential consequences of such incidents. The Bayesian network model estimates the likelihood of hydrogen leakage at approximately 4.73 × 10−4 and identifies key risk factors contributing to such events, including improper maintenance procedures, inadequate operational protocols, and insufficient operator training. The Bow-tie model is employed to visualize the causal relationships between risk factors and their potential consequences, providing a clear structure for understanding the events leading to hydrogen leakage. Fuzzy set theory is used to address the uncertainties in expert judgments regarding system parameters, enhancing the robustness of the risk analysis. To mitigate the subjectivity inherent in root node probabilities and conditional probability tables, the Noisy-OR Gate model is introduced, simplifying the determination of conditional probabilities and improving the accuracy of the evaluation. The probabilities of flash or pool fires, jet fires, and vapor cloud explosions following a leakage are calculated as 4.84 × 10−5, 5.15 × 10−5, and 4.89 × 10−7, respectively. These findings highlight the importance of strengthening operator training and enforcing stringent maintenance protocols to mitigate the risks of hydrogen leakage. The model provides a valuable framework for safety evaluation and leakage risk management in hydrogen-powered ship fuel systems.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-09
DOI: 10.3390/jmse13030523
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 524: Long-Term (1979–2024) Variation Trend in
Wave Power in the South China Sea
Authors: Yifeng Tong, Junmin Li, Wuyang Chen, Bo Li
First page: 524
Abstract: Wave power (WP) is a strategic oceanic resource. Previous studies have extensively researched the long-term variations in WP in the South China Sea (SCS) for energy planning and utilization. This study extends the analysis of long-term trends to the last year based on ERA5 (European Centre for Medium-Range Weather Forecasts Reanalysis v5) reanalysis data from 1979 to 2024. Our results mainly indicate that the trends in WP after 2011 are significantly different from those before 2011. Before 2011, the WP in the SCS primarily showed an increasing trend, but, after 2011, it shifted to a decreasing trend. This trend has seasonal differences, manifested as being consistent with the annual trend in winter and spring while being inconsistent with the annual trend in summer and autumn. It indicates that the opposite trend in WP before and after 2011 was mainly the result of WP variations in winter and spring. To illustrate the driving factor for the WP’s variations, the contemporary long-term trend of the wind fields is systematically analyzed. Analysis results reveal that, regardless of seasonal differences or spatial distribution, the two trends are consistent in most situations, indicating that wind fields are the dominant factor for the long-term variations in WP. Meanwhile, the effects of the wind fields on the WP variations can also be modulated by environmental factors such as oceanic swell propagation and local topography. This study contributes to the knowledge of the latest trends and driving factors regarding the WP in the SCS.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-09
DOI: 10.3390/jmse13030524
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 525: Geometric and Mechanical Analysis of
Selenium-Enriched Eggs
Authors: Huinan Kang, Yunsen Hu, Sakdirat Kaewunruen, Xiaozhi Hu, Jian Zhang
First page: 525
Abstract: Geometric and mechanical analyses were performed on 82 selenium-rich eggs, which underwent hydrostatic testing as 2 raw eggs, 60 steamed eggs, and 20 emptied eggshells. By analyzing the geometric and mechanical properties of the egg, we can draw inspiration from its structural design to create a pressure shell capable of effectively withstanding the immense water pressure in deep-sea environments. The major axis, minor axis, egg-shape coefficient, weight, thickness, volume, superficial area, and ultimate compressive strength were measured, and their correlations were analyzed. The thickness, egg-shape coefficient, and ultimate compressive strength were normally distributed, and many parameters were strongly correlated. Moreover, finite element analysis was conducted to evaluate the compressive resistance of egg-like pressure shells made from different materials, including metal, ceramic, resin, and selenium-enriched eggshell materials. The performance ratio of the ceramic shells was 2.6 times higher than that of eggshells, and eggshells outperformed metal and resin shells by factors of 2.14 and 4.49, respectively. The eggshells had excellent compression resistance. These findings offer novel insights into the design and optimization of egg-like pressure shells.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-09
DOI: 10.3390/jmse13030525
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 526: Machine Learning Combined with Numerical
Simulations: An Effective Way to Reconstruct the Detonation Point of
Contact Underwater Explosions with Seabed Reflection
Authors: Jacopo Bardiani, Giada Kyaw Oo D’Amore, Claudio Sbarufatti, Andrea Manes
First page: 526
Abstract: In marine engineering, the study of underwater explosion effects on naval and offshore structures has gained significant attention due to its critical impact on structural integrity and safety. In practical applications, a crucial aspect is determining the precise point at which an underwater explosive charge has detonated. This information is vital for assessing damage, implementing defensive and security strategies, and ensuring the structural integrity of marine structures. This paper presents a novel approach that combines coupled numerical simulations performed using the MSC Dytran suite with machine learning techniques to reconstruct the trigger point of underwater explosions based on onboard sensor data and leverage seabed wave reflection information. A Multi-Layer Neural Network (MLNN) was devised to identify the position of the denotation point of the charge using a classification task based on a user-defined two-dimensional grid of potential triggering locations. The MLNN underwent training, validation, and testing phases using simulation data from different underwater blast-loading scenarios for metallic target plates. Different positions of the charge, seabed typologies, and distances between the structure and the seabed are considered. The ability to accurately identify a detonation point using measurable data from onboard systems enhances the knowledge of ship and offshore structures’ response strategies and the overall safety of naval operations.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-09
DOI: 10.3390/jmse13030526
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 527: Early-Holocene Episodic Sedimentary Process on
the East Hainan Coast: High-Resolution Chronological Refinement, Titanium
Intensity and Flux Implications
Authors: Mianjin Chen, Xiao Sun, Yang Li, Yulong Xue, Wenzhe Lyu, Xuemu Wang, Yan Li
First page: 527
Abstract: Episodic sedimentary processes with significant changes in sedimentation rate have occurred on the East Hainan Coast, the inner shelf of the South China Sea, since the Last Glacial Maximum. In particular, the early-Holocene (~11.5–8.7 ka) rapid sedimentation at a mean rate of ~4.90 m/ka is crucial to understand the processes of terrigenous input to the ocean, carbon cycling and climate control in coastal-neritic sedimentary evolution. However, the chronological framework and the detailed environmental evolution remain uncertain. In this study, core sediments collected from the East Hainan Coast (code: NH01) were used to revisit the characteristics of luminescence signals by comparing the dating results using the blue-light stimulated luminescence (blue-OSL) ages and previously published post-infrared blue-light stimulated luminescence (pIR-blue OSL) ages. The results showed that both the ages agreed with each other for the fine-grained quartz fraction. The refined chronology of the early-Holocene deposits on the East Hainan Coast with higher resolution suggested that the sedimentation rate was ~0.60 m/ka before 10.97 ka, while it increased abruptly to ~5.89 m/ka during the period of 10.97–9.27 ka. According to the refined OSL chronology and the high-resolution (~2.5 cm) titanium intensity using X-ray fluorescence (XRF) scanning, the rapid sedimentation during the early Holocene was likely controlled by increased terrigenous input. The variation in Ti flux reflected the differential response between two meltwater pulse (MWP) events under the combined effects of enhanced early-Holocene monsoons and localized freshwater input. These findings highlight the compound controls of global ice-volume change, monsoon dynamics and coastal geomorphic evolution on sedimentary processes.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-10
DOI: 10.3390/jmse13030527
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 528: LT-Sync: A Lightweight Time Synchronization
Scheme for High-Speed Mobile Underwater Acoustic Sensor Networks
Authors: Chenyu Zhang, Huabing Wu
First page: 528
Abstract: Time synchronization is a crucial element of cooperativity among underwater acoustic sensor networks (UWASNs), and it plays an indispensable role in the application of and research into UWASNs. Although plenty of previous studies on time synchronization for UWASNs have been proposed and applied, most of them cannot perform well when the nodes have high mobility, and they are characterized by low energy efficiency. Tri-Message is a scheme proposed for networks in high-latency and resource-constrained environments, but it works unsatisfactorily when the nodes are movable. In that case, there is no such scheme for high-speed UWASNs with low energy consumption. Herein, we propose LT-Sync, a lightweight time synchronization scheme for high-speed mobile UWASNs. This adopts a Doppler-shift-estimating method to derive the propagation delay of high-speed UWASNs when the unsynchronized node moves uniformly in a single direction. In addition, an underwater spread-spectrum method is adopted for signal receiving to obtain the accurate Doppler shift. The simulation results show that LT-Sync is more feasible for high-speed UWASNs compared to existing methods and has high energy efficiency.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-10
DOI: 10.3390/jmse13030528
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 529: Loss Function Optimization Method and
Unsupervised Extraction Approach D-DBSCAN for Improving the Moving Target
Perception of 3D Imaging Sonar
Authors: Jingfeng Yu, Aigen Huang, Zhongju Sun, Rui Huang, Gao Huang, Qianchuan Zhao
First page: 529
Abstract: Imaging sonar is a crucial tool for underwater visual perception. Compared to 2D sonar images, 3D sonar images offer superior spatial positioning capabilities, although the data acquisition cost is higher and lacks open source references for data annotation, target detection, and semantic segmentation. This paper utilizes 3D imaging sonar to collect underwater data from three types of targets with 1534 effective frames, including a tire, mannequin, and table, in Liquan Lake, Shanxi Province, China. Based on these data, this study focuses on three innovative aspects as follows: rapid underwater data annotation, loss function optimization, and unsupervised moving target extraction in water. For rapid data annotation, a batch annotation method combining human expertise and multi-frame superposition is proposed. This method automatically generates single-frame target detection boxes based on multi-frame joint segmentation, offering advantages in speed, cost, and accuracy. For loss function optimization, a density-based loss function is introduced to address the issue of overfitting in dense regions due to the uneven distribution of point cloud data. By assigning different weights to data points in different density regions, the model pays more attention to accurate predictions in a sparse area, resulting in a 6.939 improvement in mIOU for semantic segmentation tasks, while lakebed mIOU achieved a high score of 99.28. For unsupervised moving target extraction, a multi-frame joint unsupervised moving target association extraction method called the Double DBSCAN, D-DBSCAN, is proposed. This method simulates human visual sensitivity to moving targets in water and uses a joint D-DBSCAN spatial clustering approach with single-frame and inter-frame superposition, achieving an improvement of 21.3 points in mAP. Finally, the paper summarizes the three proposed innovations and provides directions for further research.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-10
DOI: 10.3390/jmse13030529
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 530: A Prediction of the Shooting Trajectory for a
Tuna Purse Seine Using the Double Deep Q-Network (DDQN) Algorithm
Authors: Daeyeon Cho, Jihoon Lee
First page: 530
Abstract: The purse seine is a fishing method in which a net is used to encircle a fish school, capturing isolated fish by tightening a purse line at the bottom of the net. Tuna purse seine operations are technically complex, requiring the evaluation of fish movements, vessel dynamics, and their interactions, with success largely dependent on the expertise of the crew. In particular, efficiency in terms of highly complex tasks, such as calculating the shooting trajectory during fishing operations, varies significantly based on the fisher’s skill level. To address this challenge, developing techniques to support less experienced fishers is necessary, particularly for operations targeting free-swimming fish schools, which are more difficult to capture compared to those utilizing Fish Aggregating Devices (FADs). This study proposes a method for predicting shooting trajectories using the Double Deep Q-Network (DDQN) algorithm. Observation states, actions, and reward functions were designed to identify optimal scenarios for shooting, and the catchability of the predicted trajectories was evaluated through gear behavior analysis. The findings of this study are expected to aid in the development of a trajectory prediction system for inexperienced fishers and serve as foundational data for automating purse seine fishing systems.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-10
DOI: 10.3390/jmse13030530
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 531: Improved Variational Mode Decomposition in
Pipeline Leakage Detection at the Oil Gas Chemical Terminals Based on
Distributed Optical Fiber Acoustic Sensing System
Authors: Hongxuan Xu, Jiancun Zuo, Teng Wang
First page: 531
Abstract: Leakage in oil and gas transportation pipelines is a critical issue that often leads to severe hazardous accidents at oil and gas chemical terminals, resulting in devastating consequences such as ocean environmental pollution, significant property damage, and personal injuries. To mitigate these risks, timely detection and precise localization of pipeline leaks are of paramount importance. This paper employs a distributed fiber optic sensing system to collect pipeline leakage signals and processes these signals using the traditional variational mode decomposition (VMD) algorithm. While traditional VMD methods require manual parameter setting, which can lead to suboptimal decomposition results if parameters are incorrectly chosen, our proposed method introduces an improved particle swarm optimization algorithm to automatically determine the optimal parameters. Furthermore, we integrate VMD with fuzzy dispersion entropy to effectively select and reconstruct intrinsic mode functions, significantly enhancing the denoising performance. Our results demonstrate that this approach can achieve a signal-to-noise ratio of up to 24.15 dB and reduce the mean square error to as low as 0.0027, showcasing its superior capability in noise reduction. Additionally, this paper proposes a novel threshold setting technique that addresses the limitations of traditional methods, which often rely on instantaneous values and are prone to false alarms. This innovative approach significantly reduces the false alarm rate in gas pipeline leakage detection, ensuring higher detection accuracy and reliability. The proposed method not only advances the technical capabilities of pipeline leakage monitoring but also offers strong practical applicability, making it a valuable tool for enhancing the safety and efficiency of oil and gas transportation systems.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-10
DOI: 10.3390/jmse13030531
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 532: Vertical Distribution Characteristics of Sound
Field Spectrum Splitting for Moving Sound Source in SOFAR Channel
Authors: Zuoxiang Zhang, Jinrong Wu, Zhifei Fang, Yunfei Li
First page: 532
Abstract: The frequency shift of multipath sound rays induced by the motion of a sound source in an ocean waveguide environment is a crucial factor affecting the detection capabilities of both active and passive sonar systems, as well as the quality of underwater communication. Therefore, investigating the sound field characteristics of a moving sound source in the SOFAR channel is of significant importance. By comparing the spectra of continuous-wave (CW) signals with pulse widths of 1 s and 15 s received by a vertical array in SOFAR channel, it was observed that the sound field of the moving source exhibits a stable spectral splitting characteristic. Two frequency shift bright lines in the vertical direction were identified, corresponding to two sets of sound ray paths. One set of sound ray paths corresponds to the direct sound and the first surface-reflected sound, and the other set of sound ray paths corresponds to the first seabed-reflected sound and the first surface- and seabed-reflected sound. This study revealed that the spectral splitting of the moving sound source’s sound field displays a distribution trend in a depth direction similar to that of the multipath delay structure. A multipath sound ray frequency shift calculation model, based on ray theory, was developed to explain and predict the vertical distribution pattern of spectral splitting in the sound field of a moving sound source. By combining the model with measured data, it was found that the spectral splitting arises from the frequency shift differences corresponding to multipath sound ray paths. Additionally, the frequency shifts for the D&S and B&SB ray paths are generally proportional to the cosine values of the initial grazing angles of the sound waves at the emission source and the cosine values of the horizontal azimuthal angle between the source motion direction and the receiver.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-10
DOI: 10.3390/jmse13030532
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 533: Machine Learning-Based Partition Method for
Cyclic Development Mode of Submarine Soil Martials from Offshore Wind
Farms
Authors: Ben He, Mingbao Lin, Zhishuai Zhang, Bo Han, Xinran Yu
First page: 533
Abstract: Offshore wind turbines are subjected to long-term cyclic loads, and the seabed materials surrounding the foundation are susceptible to failure, which affects the safe construction and normal operation of offshore wind turbines. The existing studies of the cyclic mechanical properties of submarine soils focus on the accumulation strain and liquefaction, and few targeted studies are conducted on the hysteresis loop under cyclic loads. Therefore, 78 representative submarine soil samples from four offshore wind farms are tested in the study, and the cyclic behaviors under different confining pressures and CSR are investigated. The experiments reveal two unique development modes and specify the critical CSR of five submarine soil martials under different testing conductions. Based on the dynamic triaxial test results, the machine learning-based partition models for cyclic development mode were established, and the discrimination accuracy of the hysteresis loop were discussed. This study found that the RF model has a better generalization ability and higher accuracy than the GBDT model in discriminating the hysteresis loop of submarine soil, the RF model has achieved a prediction accuracy of 0.96 and a recall of 0.95 on the test dataset, which provides an important theoretical basis and technical support for the design and construction of offshore wind turbines.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-10
DOI: 10.3390/jmse13030533
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 534: Nonlinear Compound Function-Based Course-Keeping
Control for Ships in Rough Seas
Authors: Guoshuai Li, Shimiao Wang, Xianku Zhang, Wenjun Zhang, Zhenhuan Zhang
First page: 534
Abstract: To ensure the safe navigation of ships in rough seas while reducing steering gear energy consumption and losses, a steering control system with small rudder output angles, low steering frequency, and high control performance was designed. A third-order closed-loop gain-shaping algorithm was employed in the development of the controller, with the ultimate control strategy derived by embedding a nonlinear compound function between the proportional derivative (PD) controller and the second-order oscillation link to enhance control effectiveness. A nonlinear Nomoto model of the “Yupeng” ship was employed for simulation validation. The simulation results illustrated a 14.5% improvement in overall control performance achieved by the proposed controller compared to a nonlinear feedback controller. The controller’s robustness was additionally validated through the application of the Norrbin ship model. The proposed controller enhances the stability of ships in rough seas, effectively limiting the maximum rudder angle during turns and reducing the average rudder angle and steering frequency during navigation. This design aligns with practical requirements for maritime operations in heavy weather, contributing significantly to the economic, safe, and efficient navigation of ships.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-11
DOI: 10.3390/jmse13030534
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 535: An Underwater Localization Algorithm Based on
the Internet of Vessels
Authors: Ziqi Wang, Ying Guo, Fei Li, Yuhang Chen, Jiyan Wei
First page: 535
Abstract: Localization is vital and fundamental for underwater sensor networks. However, the field still faces several challenges, such as the difficulty of accurately deploying beacon nodes, high deployment costs, imprecise underwater ranging, and limited node energy. To overcome these challenges, we propose a crowdsensing-based underwater localization algorithm (CSUL) by leveraging the computational and localization resources of vessels. The algorithm is composed of three stages: crowdsensing, denoising, and aggregation-based optimization. In the crowdsensing stage, nodes transmit localization requests, which are received by vessels and broadcasted to nearby vessels. Using concentric circle calculations, the localization problem is transformed from a three-dimensional space to a two-dimensional plane. An initial set of potential node locations, termed the concentric circle center set, is derived based on a time threshold. The denoising stage employs a Density-Based Noise Removal (DBNR) algorithm to eliminate noise caused by vessel mobility, environmental complexity, and the time threshold, thereby improving localization accuracy. Finally, in the aggregation-based optimization stage, the denoised node location set is refined using a centroid-based approximate triangulation (CBAT) algorithm to determine the final node location. Simulation results indicate that the proposed method achieves high localization coverage without requiring anchor nodes and significantly improves localization accuracy. Additionally, since all localization computations are carried out by vessels, node energy consumption is greatly reduced, effectively extending the network’s lifetime.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-11
DOI: 10.3390/jmse13030535
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 536: Study on the Impact of Input Parameters on
Seawater Dissolved Oxygen Prediction Models
Authors: Wenqing Li, Jing Lv, Yuhang Wang, Xiangfeng Kong
First page: 536
Abstract: The concentration of dissolved oxygen (DO) in seawater is a core ecological indicator in aquaculture, and its accurate prediction is of great value for the management of marine ranching. In response to the lack of exploration on the optimization mechanism of input parameters in existing DO prediction studies, this study, based on observational data from the Goji Island marine ranching, constructed a technical framework of “parameter screening—model optimization—ecological analysis”. By integrating correlation analysis, principal component analysis (PCA), and multi-model comparison (SVM, MLP, and RF) methods, this study systematically revealed the input parameter optimization strategies and its ecological correlation mechanism. The research findings are as follows: (1) Parameter optimization can significantly improve model accuracy, and the model performance is optimal after eliminating the low-correlation parameter (Tur) (RMSE = 0.039, MAE = 0.030, R2 = 0.884). (2) The absence of key parameters (such as Sal) will lead to a significant decrease in prediction accuracy (the R2 reduction rate reaches 71.6%). (3) The parameter importance ranking is Tem > pH > Sal > Chl-a > Tur, among which Tem explains 42.3% of the variation in DO. The intelligent parameter optimization framework proposed in this study provides theoretical support for the development of a marine ranching DO monitoring system, and its technical path can be extended to the prediction of other water environment indicators. Future research will develop a parameter adaptive selection algorithm, conduct the dynamic monitoring of multi-scale environmental factors, and achieve the intelligent optimization and verification of model parameters.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-11
DOI: 10.3390/jmse13030536
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 537: Sediment Provenance and Distribution on the
Northwest African Continental Shelf
Authors: Hasnaa Nait-Hammou, Khalid El Khalidi, Otmane Khalfaoui, Ahmed Makaoui, Melissa Chierici, Chaimaa Jamal, Mohammed Idrissi, Bendahhou Zourarah
First page: 537
Abstract: This study analyzes the mineralogical and geochemical composition of 38 surface sediment samples from the northwest African continental shelf between Cap Boujdour (26.5° N) and Cap Blanc (20.5° N). Using a multiproxy approach, sediment characteristics were assessed through grain size, calcium carbonate (CaCO3), and organic carbon (Corg) measurements, along with X-ray diffraction (XRD) and X-ray fluorescence (XRF) for geochemical analysis. Bottom water properties, including temperature, salinity, and dissolved oxygen, were measured at various stations using a Conductivity, Temperature, and Depth (CTD) sensor. The results reveal that the inner shelf sediments are primarily mud, with high concentrations of terrigenous elements such as iron (Fe), silicon (Si), rubidium (Rb), and potassium (K), with Fe and Si concentrations ranging from 2.1 to 4.3 wt%. The middle and outer shelf sediments are dominated by biogenic carbonates, with CaCO3 levels approaching 65%, and elevated calcium (Ca) and strontium (Sr) content. These areas also exhibit the highest bottom water temperatures (up to 16 °C), salinity (36%), and moderate oxygen levels (2–4 mL/L). Slope sediments are enriched with mud and montmorillonite, and aeolian contributions are more pronounced south of Dakhla, as indicated by elevated quartz levels (up to 20%) and the presence of illite, aluminum oxide (Al2O3), and iron oxide (Fe2O3). This study provides valuable new insights into sedimentary processes on the northwest African shelf, offering implications for regional environmental management and resource exploration.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-11
DOI: 10.3390/jmse13030537
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 538: A Symbol Conditional Entropy-Based Method for
Incipient Cavitation Prediction in Hydraulic Turbines
Authors: Mengge Lv, Feng Li, Yi Wang, Tianzhen Wang, Demba Diallo, Xiaohang Wang
First page: 538
Abstract: The accurate prediction of incipient cavitation is of great significance for ensuring the stable operation of hydraulic turbines. Hydroacoustic signals contain essential information about the turbine’s operating state. Considering that traditional entropy methods are easily affected by environmental noise when the state pattern is chaotic, leading to the extracted cavitation features not being obvious, a Symbol Conditional Entropy (SCE) feature extraction method is proposed to classify the original variables according to different state patterns. The uncertainty is reduced, and the ability to extract fault information is improved, so more effective cavitation features can be extracted to describe the evolving trend of cavitation. The extracted cavitation features are used as indicators to predict incipient cavitation. In order to avoid missing critical information in the prediction process, an interval mean (IM) algorithm is proposed to determine the initial prediction point. The effectiveness of the proposed method is validated with hydroacoustic signals collected at the Harbin Institute of Large Electric Machinery. The root mean square error (RMSE), mean absolute error (MAE), and mean absolute percentage error (MAPE) of incipient cavitation prediction results decreased to 0.0018, 0.0015, and 1.59%, respectively. The RMSE, MAE, and MAPE of the proposed SCE decreased by 84.62%, 85.29%, and 87% compared with the Permutation Entropy (PE) method. The comparison results with different prediction algorithms show that the proposed SCE has excellent trend prediction performance and high precision.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-11
DOI: 10.3390/jmse13030538
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 539: Prediction of Water Quality Index of Island
Counties Under River Length System—A Case Study of Yuhuan City
Authors: Cheng Zhang, Lei Wang, Chuan Lin, Minyuan Lu
First page: 539
Abstract: In order to cope with the extremely difficult challenges of water pollution control, China has widely implemented the river chief system. The water quality monitoring of surface water environment, as a solid defense line to safeguard human health and ecosystem balance, is of great importance in the river chief system. As a well-known island county in China, Yuhuan City holds even more precious water resources. Leveraging machine learning technology to develop water quality prediction models is of great significance for enhancing the monitoring and evaluation of surface water environment quality. This case study aims to evaluate the effectiveness of six machine learning models in predicting water quality index (CWQI) and uses SHAP (Shapley Additive exPlans) as an interpretability analysis method to deeply analyze the contribution of each variable to the model’s prediction results. The research results show that all models exhibited good performance in predicting CWQI, and as the number of significantly correlated variables in the input variables increased, the prediction accuracy of the models also showed a gradual improvement trend. Under the optimal input variable combination, the Extreme Gradient Boosting model demonstrated the best prediction performance, with a root mean square error (RMSE) of 0.7081, a mean absolute error (MAE) of 0.4702, and an adjusted coefficient of determination (Adj.R2) of 0.6400. Through SHAP analysis, we found that the concentrations of TP (total phosphorus), NH3-N (ammonia nitrogen), and CODCr (chemical oxygen demand) have a significant impact on the prediction of CWQI in Yuhuan City. The implementation of the river chief system not only enhances the pertinence and effectiveness of water quality management, but also provides richer and more accurate data support for machine learning models, further improving the accuracy and reliability of water quality prediction models.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-11
DOI: 10.3390/jmse13030539
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 540: Research on the Detection Method of
Cyanobacteria in Lake Taihu Based on Hyperspectral Data from ZY-1E
Authors: Qinshun Luo, Dongzhi Zhao, Zhongfeng Qiu, Sheng Jiang, Yuanzhi Zhang
First page: 540
Abstract: Cyanobacterial blooms are a widespread phenomenon in aquatic ecosystems worldwide, causing significant harm to the ecological environment. Lake Taihu is the third-largest freshwater lake in China. The region has been increasingly affected by cyanobacterial blooms, drawing greater attention from people. Currently, numerous models have been developed for detecting algal bloom based on spectral characteristics. However, the intuitive basis of optical detection lies in water color. Therefore, constructing an algal bloom detecting model from the perspective of chromaticity is worth exploring. This study constructed an algal bloom detecting model based on chromatic parameters, DFLH, and IAVW by using hyperspectral data from Lake Taihu. It further applied the model to the ZY-1E hyperspectral satellite for large-scale algal bloom monitoring. The threshold for detecting cyanobacterial blooms is defined as DFLH > 0.013 sr−1 and Hue Angle > 170.58 degrees; the threshold for the normal water is defined as DFLH < 0.013 sr−1. The parameter thresholds for the floating leaf vegetation range were defined as DFLH > 0.013 sr−1, Saturation < 0.07, and IAVW > 598 nm. Through the validation, in the modeling dataset, the overall accuracy (OA) value is 0.81 and the F1-score is 0.86. In the validation dataset, the overall accuracy (OA) value is 0.83 and the F1-score is 0.89. The model demonstrates good detecting performance. Regarding its application on the ZY-1E satellite, we validated the detection results accuracy through matching synchronized in situ algal density data. The results are as follows: OA is 0.95, and the F1-score is 0.95. The results above indicate that the algal bloom detection method developed in this study had a good accuracy in detecting algal blooms in Lake Taihu on 6 September 2020. This study provided the algae bloom detecting model based on water color characteristics in Lake Taihu, which had high detecting accuracy.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-11
DOI: 10.3390/jmse13030540
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 541: The Impact of Air–Sea Flux
Parameterization Methods on Simulating Storm Surges and Ocean Surface
Currents
Authors: Li Cai, Bin Wang, Wenqian Wang, Xingru Feng
First page: 541
Abstract: As the primary driver of energy transfer between atmospheric and oceanic systems, the air–sea momentum flux fundamentally governs coupled model dynamics through its regulation of wind stress partitioning. Given the complexity of the physical processes involved, simplified representations of these interactions are widely adopted to balance computational efficiency and physical fidelity. This systematic evaluation of five wind stress parameterizations reveals scheme-dependent variability in momentum partitioning efficiency, particularly under typhoon conditions. Our results quantify how the wind stress drag coefficient’s formulation alters atmosphere–ocean feedback, with wave-state aware schemes exhibiting superior surge prediction accuracy compared to wind-speed-dependent approaches. Specifically, a larger wind stress drag coefficient leads to increased atmospheric bottom stress and sea surface stress, resulting in weaker winds and larger sea surface currents and storm surges. These findings provide actionable guidelines into the performance and sensitivity of various air–sea coupled models and offer useful suggestions for improving operational marine forecasting systems.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-12
DOI: 10.3390/jmse13030541
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 542: A Multi-Resolution Sequence Method with Strong
Constraints for Marine Gravity Matching Navigation
Authors: Ning Mao, An Li, Jiangning Xu, Fangjun Qin
First page: 542
Abstract: The navigation and positioning of underwater vehicles is challenging work, especially when there is already a large initial position error, and there is an increasing concern about how to quickly correct the position error. To enhance positioning accuracy under large initial positioning errors, this paper proposes a multi-resolution sequence method with a strong constraint marine gravity-matching navigation algorithm and validates it through field experiments. First, the fundamental principles and common optimization approaches of the standard Terrain Contour Matching (TERCOM) and Iterative Closest Contour Point (ICCP) algorithms are introduced, the limitations of the sequence-matching algorithms are analyzed, and a multi-resolution sequence-matching fusion framework is designed. Then, the constrained models incorporating positional, navigational, and gravitational parameters are designed, and a strongly constrained multi-resolution sequence-matching algorithm is proposed. Finally, the performance of the method is verified by three field test trajectories with an initial position error of about 6 nautical miles. The field test results show that the proposed method has better accuracy and reliability under large initial position errors.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-12
DOI: 10.3390/jmse13030542
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 543: A Shoreline Screening Framework for Identifying
Nature-Based Stabilization Measures Reducing Storm Damage in the Florida
Keys
Authors: Diana Mitsova, Kevin Cresswell, Chris Bergh, Melina Matos, Stephanie Wakefield, Kathleen Freeman, Willian Carlos Lima
First page: 543
Abstract: With elevations mostly less than 2 m, the Florida Keys, an island chain stretching nearly two hundred kilometers from Biscayne Bay to Key West, Florida, is among the most vulnerable coastal regions globally. As the threats from tropical cyclones, storm surges, and sea level rise intensify, urbanized areas increasingly rely on shoreline armoring, disregarding the negative effects on coastal habitats. Living shorelines, which integrate coastal vegetation to stabilize erodible shoreline segments or enhance existing grey infrastructure, have successfully addressed some of these challenges. We present a decision framework for evaluating the suitability of different stabilization methods for existing shoreline conditions. The framework incorporates a Shoreline Relative Exposure Index (SREI) based on shoreline orientation, wind and wave exposure, shoreline slope, bathymetry, nearshore habitat, and storm surge. To refine this framework, we conducted an expert opinion survey to determine parameter weights. The results will inform decisions on using vegetated shorelines alone or with structural elements to reduce wave action, control erosion, and protect Florida Keys communities from storm damage. Implementing innovative shoreline stabilization methods is crucial as climate change and population growth are expected to exacerbate flood management challenges.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-12
DOI: 10.3390/jmse13030543
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 544: Vibroacoustic Response of a Disc-Type Underwater
Glider During Its Entry into Water
Authors: Zhaocheng Sun, Yanting Yu, Dong Li, Chuanlin He, Yue Zhang
First page: 544
Abstract: Underwater gliders are extensively employed in oceanographic observation and detection. The structural characteristics of thin-wall shells are more susceptible to vibrations from internal mechanical components; this noise emission becomes more complex with the presence of water surfaces. The finite element method (FEM) is introduced to discuss the dynamic performance of cylindrical shells with different lengths. The acoustic-structure coupling, together with the effect of the water surface, is validated by comparisons with experimental or analytical solutions under three cases: half-filled, half-submerged, and partially submerged in fluid. Compared to the verification result, the relative error of the eigenfrequency derived from the numerical result is less than 3%, and then the mesh division and boundary conditions are adjusted to calculate the vibroacoustic response of a disc-type glider. During its water entry process, there are six distinct bright curves in frequency–depth spectra of sound pressure radiated from a partially immersed disc-type glider. The first curve is continuous, while the remaining five curves display discontinuities around a region where the geometric curvature changes gradually. As the submerged depth increases, this causes a shift in the resonance frequencies, evidenced by the curves transitioning from higher to lower frequencies.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-12
DOI: 10.3390/jmse13030544
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 545: The Mooring Optimization and Hydrodynamic
Characteristics of the Combined Concept of a 15 MW FOWT with WECs
Authors: Yi Yang, Shi Liu, Xinran Guo, Wen Chen, Tao Tao, Hao Wu, Kai Wang
First page: 545
Abstract: To reduce the cost of offshore wind and wave power, an innovative combined wind–wave energy generation system constituting of a 15 MW semi-submersible floating offshore wind turbine (FOWT) and four torus-type wave energy converters (WECs) is proposed. A wholly coupled numerical model of aero-hydro-elastic-servo-mooring was built to evaluate the mooring line and motion dynamics of this novel combined system. Additionally, a practical mooring optimization framework is proposed with the Latin Hypercube sampling method, Kriging model, and the combined optimization techniques of the Genetic Algorithm and Gradient Algorithm. The optimization results demonstrate that the optimized mooring scheme satisfies all the strict constraints, validating the effectiveness of the optimization method. Moreover, the hydrodynamic characteristics of the combined system and the effects of the WECs on the mooring system under both rated and extreme conditions are discussed, including changes in time-series mooring tension, power spectral density, and statistical characteristics. The research findings provide a reference for the further development and optimization of this novel combined system, contributing to the efficient utilization of offshore renewable energy.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-12
DOI: 10.3390/jmse13030545
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 546: Quantitative Analysis of Bound Water Content in
Marine Clay and Its Influencing Factors During the Freezing Process by
Nuclear Magnetic Resonance
Authors: Xuehan Shan, Huie Chen, Chuqiao Meng, Zuojun Lv, Qingbo Yu, Zhaoxi Wang, Qing Wang
First page: 546
Abstract: The change in bound water content with temperature is a core issue in studying temperature effects in clayey soils. This study used nuclear magnetic resonance (NMR) techniques to measure pore water in three types of marine clay, ranging from inland to coastal areas. The T2 cutoff values were proposed to distinguish between bulk water, capillary water, and bound water, and the curves of unfrozen water and bound water content with changing temperatures were obtained during the freezing process. Additionally, the impact of soil properties on bound water content was analyzed. The research findings indicated that the pore water in marine clay is dominated by bound water, and the change in bound water content with temperature in each soil layer can be divided into four stages: the trace phase change stage, the intense phase change stage, the transitional phase change stage, and the stabilizing stage. Further, the effect of soil properties such as organic matter content, soluble salt content, and cation exchange capacity on bound water content was illustrated, and clay content and bound water content were found not to be strictly positively correlated.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-12
DOI: 10.3390/jmse13030546
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 547: Hierarchical Behavior Planning Framework for
Networked MSV Systems in Inland Waterway Traffic Separation Schemes
Authors: Wei Tao, Lizheng Wang, Jian Tan, Man Zhu, Yuanqiao Wen
First page: 547
Abstract: Ensuring safety and preventing accidents in waterway channels are critical challenges for networked marine surface vessel systems (NMSVs). This study introduces a regulation-aware decision-making system designed to minimize traffic conflicts and enhance navigational safety in inland waterway traffic separation schemes. The proposed framework integrates a hierarchical conditional state machine with chance-constrained model predictive control, allowing NMSVs to handle complex traffic situations while complying with safety regulations. The hierarchical conditional state machine effectively identifies vessel maneuver states, implementing safety constraints that proactively avoid collisions. Meanwhile, the chance-constrained model predictive control optimizes vessel trajectories, factoring in uncertainties and potential risks, while simultaneously enhancing operational efficiency. Simulation and experimental results demonstrate that the proposed system significantly reduces the likelihood of accidents and improves overall safety by efficiently managing vessel interactions. Compared to traditional methods, the regulation-aware approach ensures better collision avoidance, greater regulation compliance, and superior safety performance. This study confirms that the proposed decision-making system can be effectively implemented in real time, offering practical benefits for improving waterway safety and mitigating accident risks.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-12
DOI: 10.3390/jmse13030547
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 548: Fluid–Structure Interaction of a
Darrieus-Type Hydrokinetic Turbine Modified with Winglets
Authors: Emerson Escobar Nunez, Diego García González, Omar Darío López, Juan Pablo Casas Rodríguez, Santiago Laín
First page: 548
Abstract: The growing demand for electricity in developing countries has called attention and interest to renewable energy sources to mitigate the adverse environmental effects caused by energy generation through fossil fuels. Among different renewable energy sources, such as photovoltaic, wind, and biomass, hydraulic energy represents an attractive solution to address the demand for electricity in rural areas of Colombia that are not connected to the electrical grid. In the current paper, the fluid–structure interaction (FSI) of a recently designed Vertical-Axis Hydrokinetic Turbine (VAHT) Straight-Bladed (SB) Darrieus-type, modified with symmetric winglets, was studied by implementing the sliding mesh method (SMM). By coupling with Computational Fluid Dynamics (CFD) numerical simulations, the FSI study demonstrated that the hydrodynamic loads obtained can cause potential fatigue damage in the blades of the Straight-Bladed (SB) Darrieus VAHT. Fatigue life was assessed using the stress–life (S-N) approach, and materials such as structural steel, short glass fiber reinforced composites (SGFRC), and high-performance polymers (HPP), such as PEEK, were studied as potential materials for the construction of the blades. FSI results showed that the biaxiality index (BI) provides a good understanding of the dominant stresses in the blades as the azimuth angle changes. It was also shown that structural steel and PEEK are good materials for the manufacturing of the blades, both from a fatigue resistance and modal perspective.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-12
DOI: 10.3390/jmse13030548
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 549: Cooperative Formation Control of Multiple Ships
with Time Delay Conditions
Authors: Wei Tao, Jian Tan, Zhongyi Sui, Lizheng Wang, Xin Xiong
First page: 549
Abstract: The cooperative control of multiple autonomous surface vehicles (ASVs) is a critical area of research due to its significant applications in maritime operations, such as search and rescue and environmental monitoring. However, challenges such as communication delays and dynamic topologies often hinder stable cooperative control in practical scenarios. This study addresses these challenges by developing a formation control method based on consensus theory, focusing on both formation control and time delay. First, a simplified ASV characteristic model is established, and a basic consensus control algorithm is designed and analyzed for stability, considering different communication topologies. Then, to handle delays, the formation control method is extended, and the stability of the revised algorithm is rigorously proven using the Lyapunov function. Simulation results demonstrate that the proposed control strategy effectively maintains formations, even in the presence of communication delays. In the end, comparative simulations are carried out to demonstrate the effectiveness and robustness of the proposed controller. Simulation results demonstrate that the proposed control strategy effectively maintains formations, even in the presence of communication delays, with a convergence time of approximately 100 s and a formation error stabilizing at around 7 m. This research lays a foundation for more reliable cooperative control systems for ships, with potential applications in a variety of maritime and autonomous systems.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-12
DOI: 10.3390/jmse13030549
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 550: Three-Dimensional Numerical Simulation of the
Vortex-Induced Motion Response of Semi-Submersible Platforms Under
Wave-Current Coupling Effect
Authors: Yankun Yin, Jin Yan, Chushan Deng, Dapeng Zhang
First page: 550
Abstract: The vortex-induced motion response of semi-submersible platforms can result in fatigue damage to the mooring and riser systems, thereby compromising production safety. Consequently, investigating the characteristics and mechanisms of vortex-induced motion response under complex marine environments holds significant importance in the field of offshore engineering. This study utilizes the SA-DES numerical simulation method to establish a fluid-structure coupling model that simulates the vortex-induced motion of semi-submersible platforms under uniform flow and wave-current interactions, with a focus on key parameters such as response amplitude, frequency, and fluid forces. To ensure the accuracy of the simulations, the numerical model aligns with the physical model tests in terms of dimensions and environmental conditions. The numerical results demonstrate a strong correlation with experimental data under both uniform flow and wave-current coupling conditions, confirming the model’s validity. The results reveal a significant “LOCK-IN” phenomenon occurring within reduced velocity (dimensionless velocity, the ratio of velocity to characteristic length) range of 6 to 8 under uniform flow conditions, with the response amplitude at an incoming flow angle of 45° exceeding that at 0°. In wave-current coupling conditions, the response amplitude is generally lower than that observed under uniform flow, indicating that the presence of waves attenuates the vortex-induced motion. Furthermore, the frequency of the vortex-induced motion is found to be similar to the natural frequency of the platform’s transverse motion, suggesting that the vortex-induced motion may be attributed to a resonance phenomenon induced by pulsating lift force from vortex shedding. These findings validate the effectiveness and accuracy of the SA-DES numerical simulation method in predicting the vortex-induced motion of semi-submersible platform.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-12
DOI: 10.3390/jmse13030550
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 551: Deploying Liquefied Natural Gas-Powered Ships in
Response to the Maritime Emission Trading System: From the Perspective of
Shipping Alliances
Authors: Yulong Sun, Jianfeng Zheng, Xin He, Zhihao Zhao, Di Cui
First page: 551
Abstract: In response to climate change caused by shipping, the maritime emission trading system (METS) is used to reduce ship carbon emissions, and the METS also imposes additional costs on shipping carriers through emission permit trading. This paper focuses on the deployment of liquefied natural gas-powered (LNG-powered) ships for shipping alliances to comply with the METS. From the perspective of a liner alliance, we investigate how to determine the deployment of LNG-powered ships and how ship emissions will be affected. To investigate these problems, we propose an LNG-powered fleet deployment problem, which integrates slot co-chartering and emission permit trading, to determine the fleet deployment of LNG-powered and oil-powered ships, ship speeds and container shipment. To formulate our proposed problem, we develop a mixed-integer linear programming model, which can be solved effectively by CPLEX. Numerical experiments are provided to assess the effectiveness of our proposed model.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-12
DOI: 10.3390/jmse13030551
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 552: Study on the Influence of Water Color on Signal
Directionality in Laser-Induced Acoustic Processes
Authors: Tongchang Zhang, Xiaolong Cao, Qi Tan, Yiguang Yang, Yuchen Du, Jiaqi Yuan, Tengyuan Cui, Jianquan Yao
First page: 552
Abstract: Implementing information encoding in laser acoustic signals by altering the medium’s color is one of the current hot research topics. Modulating the color of the medium can modulate the directionality of laser acoustic signals; however, there has been little research on the impact of water color on laser acoustic signals. This paper investigates the relationship between the directionality of laser acoustic signals and water color, innovatively proposing a conical sound source model. It points out that the ratio of the model’s radius (r) to the model’s vertical line (d) is a decisive factor affecting directionality. Through simulations and experiments, it has been verified that laser acoustic signals exhibit no significant directionality (r/d = 10) and that the energy distribution of sound signals in the vertical direction significantly decreases (r/d = 0.4). Sound signal directivity and absorption rate were studied in the environment of red, blue, and yellow water, and the time–frequency characteristics were also studied. The acoustic signals produced by laser breakdown of different colors have obvious time–frequency characteristic differences, among which the signal intensity generated by laser incident on yellow water is 180.13 dB and the signal intensity generated by laser incident on black water is 168.31 dB. The peak frequency of sound signal generated by laser breakdown of yellow water is the highest, which is 21,240 Hz, and the peak frequency of sound signal generated by laser breakdown of water is the lowest, which is 8828 Hz. There is an obvious positive correlation between the peak frequency of sound signals and the laser absorption rate, and calculation of the optimal water color corresponding to the highest detection threshold at different distances provides guidance for the application of laser acoustic communication.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-12
DOI: 10.3390/jmse13030552
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 553: Probabilistic Risk Framework for Nuclear- and
Fossil-Powered Vessels: Analyzing Casualty Event Severity and Sub-Causes
Authors: Handan Tanyildizi-Kokkulunk, Görkem Kökkülünk, John Settles
First page: 553
Abstract: Maritime activities pose significant safety risks, particularly with the growing presence of nuclear-powered vessels (NPVs) alongside traditional fossil-powered vessels (FPVs). This study employs a probabilistic risk assessment (PRA) approach to evaluate and compare accident hazards involving NPVs and FPVs. By analyzing historical data from 1960 to 2024, this study identifies risk patterns, accident frequency (probability), and severity levels. The methodology focuses on incidents such as marine incidents, marine casualties, and very serious cases with sub-causes. Key findings reveal that Russia exhibits the highest risk for very serious incidents involving both NPVs and FPVs, with a significant 100% risk for NPVs. China has the highest FPV risk, while France and the USA show above-average risks, particularly for marine casualties and very serious incidents. Moreover, collision is the most significant global risk, with a 26% risk for NPVs and 34% for FPVs, followed by fire hazards, which also pose a major concern, with a 17% risk for NPVs and 16% for FPVs, highlighting the need for enhanced safety and fire-prevention measures. In conclusion, comparative analysis highlights the need for enhanced stability improvements, fire prevention, and maintenance practices, particularly in the UK, France, Russia, and China. This study underscores the importance of targeted safety measures to mitigate risks, improve ship design, and promote safer maritime operations for both nuclear- and fossil-fueled vessels.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-13
DOI: 10.3390/jmse13030553
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 554: Data-Driven Approach to Safety Control in
Jacket-Launching Installation Operations
Authors: Sheng Chen, Mingxin Li, Yankun Liu, Xu Bai
First page: 554
Abstract: Installing offshore wind jackets faces increasing risks from dynamic marine conditions and is challenged by trajectory deviations due to coupled hydrodynamic and environmental factors. To address the limitations of software, such as long simulation times and tedious parameter adjustments, this study develops a rapid prediction model combining Radial Basis Function (RBF) and Backpropagation (BP) neural networks. The model is enhanced by incorporating both numerical simulation data and real-world measurement data from the launching operation. The real-world data, including the barge attitude before launching, jacket weight distribution, and actual environmental conditions, are used to refine the model and guide the development of a fully parameterized adaptive controller. This controller adjusts in real time, with its performance validated against simulation results. A case study from the Pearl River Mouth Basin was conducted, where datasets—capturing termination time, six-degrees-of-freedom motion data for the barge and jacket, and actual environmental conditions—were collected and integrated into the RBF and BP models. Numerical models also revealed that wind and wave conditions significantly affected lateral displacement and rollover risks, with certain directions leading to heightened operational challenges. On the other hand, operations under more stable environmental conditions were found to be safer, although precautions were still necessary under strong environmental loads to prevent collisions between the jacket and the barge. This approach successfully reduces weather-dependent operational delays and structural load peaks. Hydrodynamic analysis highlights the importance of directional strategies in minimizing environmental impacts. The model’s efficiency, requiring a fraction of the time compared to traditional methods, makes it suitable for real-time applications. Overall, this method provides a scalable solution to enhance the resilience of marine operations in renewable energy projects, offering both computational efficiency and high predictive accuracy.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-13
DOI: 10.3390/jmse13030554
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 555: The Optimization of Four Key Parameters in the
XBeach Model by GLUE Method: Taking Chudao South Beach as an Example
Authors: Yunyun Gai, Longsheng Li, Zikang Li, Hongyuan Shi
First page: 555
Abstract: When the XBeach model is used to simulate beach profiles, the selection of four sensitive parameters—facua, gammax, eps, and gamma—is crucial. Among these, the two key parameters, facua and gamma, are particularly sensitive. However, the XBeach model does not specify the exact choice of these four key parameters, offering only a broad range for each one. In this paper, we investigate the applicability of tuning these four parameters within the XBeach model. We employ Generalized Likelihood Uncertainty Estimation (GLUE) to optimize the model settings. The Brier Skill Score (BSS) for each parameter combination is calculated to quantify the likelihood probability distribution of each parameter. The optimal parameter set (facua = 0.20, gamma = 0.50) was ultimately determined. Here, the facua parameter represents the degree of influence of wave skewness and asymmetry on the direction of sediment transport, while the gamma parameter represents the equivalent random wave in the wave dissipation model and is used to calculate the probability of wave breaking. Six profiles of the southern beach on Chudao Island are selected to validate the results, establishing the XBeach model based on profile measurement data before and after Typhoon “Lekima”. The results indicate that after parameter optimization, the simulation accuracy of XBeach is significantly improved, with the BSS increasing from 0.3 and 0.17 to 0.68 and 0.79 in P1 and P6 profiles, respectively. This paper provides a recommended range for parameter values for future research.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-13
DOI: 10.3390/jmse13030555
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 556: A Low-Complexity Path-Planning Algorithm for
Multiple USVs in Task Planning Based on the Visibility Graph Method
Authors: Kai Xue, Zhiqin Huang, Ping Wang, Zeyu Xu, Decheng Kong
First page: 556
Abstract: Path planning for multiple unmanned surface vehicles (USVs) in task planning is a high-complexity problem. When the number of USVs is n, the computational complexity is usually as high as On2, as paths need to be planned from different start points to different target points. In this paper, we propose a low-complexity path-planning algorithm (LCPP) for multiple USVs based on the visibility graph method. First, all paths between the start points, target points, and obstacle vertices are separately planned with the low-complexity On. After that, the Dijkstra algorithm is employed to find the shortest path from each start point to all target points, also with the low-complexity On. To enhance the safety of each USV traveling along the edge of obstacles, the parameters of the adaptive line-of-sight (ALOS) guidance algorithm are optimized using the simulated annealing algorithm. The simulation results show that this algorithm outperforms others in calculation time when dealing with a large number of USVs.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-13
DOI: 10.3390/jmse13030556
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 557: Textural, Mineralogical and Chromatic
Characterisation of the Beach Sediments of Cuba: Management Implications
Authors: Ángel Sánchez-Bellón, Eduardo Molina-Piernas, Giorgio Anfuso, Francisco Asensio-Montesinos, Juan Alfredo Cabrera-Hernández, Camilo M. Botero, Enzo Pranzini
First page: 557
Abstract: Although it is practically impossible to find locations without a massive flux of tourists, few beach destinations present a great attraction due to their privileged natural characteristics. This is often the case for sites that show splendid beach sands. To maintain their tourist attraction and related economic income, it is essential to know sediment characteristics such as their mineralogical composition, particle size, and colour. This paper presents a textural, chromatic, and mineralogical database of 90 beaches in Cuba. The composition of sediments was identified by stereomicroscopy, their texture by digital image analysis, sand colour according to the CIE space and X-ray diffraction, and fluorescence and electron microscopy were used to determine sediment mineralogy. Two main groups of beaches were identified: the lighter and brighter beaches of the cays are dominated by the association of authigenic carbonates (aragonite, kutnohorite, and calcite) while the south and northeastern coasts of eastern Cuba are dominated by darker sediments with larger grain sizes composed of amphibole, pyroxene, serpentines, chlorites, quartz, and plagioclase of detrital origin. The data obtained will allow the design of proper management actions of coastal resources, i.e., the maintaining of beaches’ sediment quality after nourishment works and, at the same time, the promotion and development of new, presently undervalued areas.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-13
DOI: 10.3390/jmse13030557
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 558: A Self-Tuning Variable Universe Fuzzy PID
Control Framework with Hybrid BAS-PSO-SA Optimization for Unmanned Surface
Vehicles
Authors: Huixia Zhang, Zhao Zhao, Yuchen Wei, Yitong Liu, Wenyang Wu
First page: 558
Abstract: In this study, a hybrid heading control framework for unmanned surface vehicles (USVs) is proposed, combining variable domain fuzzy Proportional–Integral–Derivative (VUF-PID) with an improved algorithmic Beetle Antennae Search–Particle Swarm Optimization–Simulated Annealing (BAS-PSO-SA) optimization to address the multi-objective control challenge. Key innovations include a self-tuning VUF mechanism that improves disturbance rejection by 42%, a weighted adaptive optimization strategy that reduces parameter tuning iterations by 37%, and an asymmetric learning factor that balances global exploration and local refinement. Benchmarks using Rastrigin, Griewank, and Sphere functions show superior convergence and 68% stability improvement. Ocean heading simulations of a 7.02 m unmanned surface vehicle (USV) using the Nomoto model show a 91.7% reduction in stabilization time, a 0.9% reduction in overshoot, and a 30% reduction in optimization iterations. The experimental validation under wind and wave disturbances shows that the heading deviation is less than 0.0392°, meeting the IMO MSC.1/Circ.1580 standard, and an 89.5% improvement in energy efficiency. Although the processing time is 12.7% longer compared to the GRO approach, this framework lays a solid foundation for ship autonomy systems, and future enhancements will focus on MPC-based time delay compensation and Field-Programmable Gate Array (FPGA) acceleration.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-13
DOI: 10.3390/jmse13030558
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 559: Characteristics and Rapid Prediction of Seismic
Subsidence of Saturated Seabed Foundation with Interbedded Soft
Clay–Sand
Authors: Liuyuan Zhao, Miaojun Sun, Jianhong Ye, Fuqin Yang, Kunpeng He
First page: 559
Abstract: Seabed foundations consisting of interbedded layers of saturated soft clay and sand deposited during the Quaternary period are widely distributed in the coastal areas of Southeastern China. These soil foundations are prone to significant settlement under seismic loading. The study of the seismic dynamic response characteristics of saturated foundations with interbedded soft clay–sand and the development of rapid prediction models are essential for controlling settlement and ensuring the service safety of marine structures. A total of 4000 sets of seabed foundation models are randomly generated, with layers of saturated soft clay and sand and with a random distribution of layer thickness and burial depth. The mechanical behavior of saturated soft clay is described using the Soft Clay model based on the boundary surface theory, and the generalized elastoplastic constitutive model PZIII is used to characterize the mechanical behavior of sandy soil. The finite element platform FssiCAS is employed for a computational analysis to study the characteristics of seismic subsidence in saturated seabed foundations with interbedded soft clay–sand. A machine learning model is implemented based on the Random Forest algorithm, in which 3200 sets of numerical simulation results are used for model training, and 800 sets are used for validating the model’s reliability. The results show that under seismic excitation, the pore water pressure within the saturated seabed foundation with interbedded soft clay–sand accumulates, effective stress decreases, and the seabed foundation softens, to a certain extent. During the post-seismic consolidation phase, significant settlement of the seabed foundation occurs. The fast prediction model based on the Random Forest algorithm could reliably predict the settlement characteristics of submarine foundations. This research provides a new technological avenue for the rapid prediction of the seismic settlement of submarine foundations, which could be of use in engineering design, assessment, and prediction.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-13
DOI: 10.3390/jmse13030559
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 560: Review of Research Progress on the Influence of
Groundwater Discharge on Seabed Stability
Authors: Zhentian Jia, Hongxian Shan, Hanlu Liu, Zhengrong Zhang, Long Jiang, Siming Wang, Yonggang Jia, Yongzheng Quan
First page: 560
Abstract: Submarine groundwater discharge (SGD) refers to the flow of groundwater that enters seawater through the seabed surface at the edge of the coastal shelf. During this discharge process, seepage and initiation can easily trigger seabed instability, which significantly influences the breeding, occurrence, and evolution of marine geological events. The narrow distribution of land near the coastline and the substantial flux of groundwater discharge are closely associated with typical seabed geological events, such as submarine landslides and collapse pits, which are prevalent in the sea area. This paper analyzes the current research status of SGD both domestically and internationally, elucidates the interaction mechanisms between groundwater discharge and the seabed, and integrates existing studies on discharge-induced slope instability, collapse pit formation, and seabed erosion and resuspension. It summarizes and evaluates the existing research on the influence of seabed groundwater discharge on the evolution of seabed geological structures, identifies key scientific problems that urgently need to be addressed, and proposes future research directions that require further emphasis. Additionally, the paper conducts research on the mechanisms by which groundwater discharge affects seabed stability, providing valuable insights for the study of coastal zones in China. It also offers a scientific basis for enhancing the understanding of the generation mechanisms of marine geological events and improving the technological capabilities for their prevention and control.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-13
DOI: 10.3390/jmse13030560
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 561: Nonlinear Sliding-Mode Super-Twisting Reaching
Law for Unmanned Surface Vessel Formation Control Under Coupling Deception
Attacks
Authors: Yifan Wang, Qiang Zhang, Yaping Zhu, Yancai Hu, Xin Hu
First page: 561
Abstract: In this paper, a nonlinear sliding-mode super-twisting reaching law algorithm is designed to address the problem of coupling interference under deception attacks and actuator physical faults in USV formations during cooperative mining operations of a USVs-ROVs system. First, a USV model with attacks and disturbances is established, and a leader–follower formation system is designed. Then, based on the reaching law, the state error dynamic chatter can be effectively solved when it is far away from and reaches the sliding surface; a nonlinear sliding super-twisting reaching law is designed to improve the chatter characteristics of the sliding surface. Furthermore, to solve the problems of low fitting accuracy regarding control anomaly information and the difficulty of fending off signal-data interference attacks, a nonlinear saturation fault-tolerant filtering mechanism and a nonlinear fitting factor are designed. Finally, the stability of the algorithm is verified through Lyapunov theory. Under the same coupling deception probability, the nonlinear sliding-mode super-twisting reaching law algorithm designed in this paper enables the leader ship and each follower ship to reach stability within about 12s, and the formation system maintains its formation while also improving the control accuracy of each individual ship.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-13
DOI: 10.3390/jmse13030561
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 562: Mathematical Modeling of Two-Dimensional Depth
Integrated Nonlinear Coupled Boussinesq-Type Equations for Shallow-Water
Waves with Ship-Born Generation Waves in Coastal Regions
Authors: Vinita, Prashant Kumar
First page: 562
Abstract: A hybrid computational framework integrating the finite volume method (FVM) and finite difference method (FDM) is developed to solve two-dimensional, time-dependent nonlinear coupled Boussinesq-type equations (NCBTEs) based on Nwogu’s depth-integrated formulation. This approach models nonlinear dispersive wave forces acting on a stationary vessel and incorporates a frequency dispersion term to represent ship-wave generation due to a localized moving pressure disturbance. The computational domain is divided into two distinct regions: an inner domain surrounding the ship and an outer domain representing wave propagation. The inner domain is governed by the three-dimensional Laplace equation, accounting for the region beneath the ship and the confined space between the ship’s right side and a vertical quay wall. Conversely, the outer domain follows Nwogu’s 2D depth-integrated NCBTEs to describe water wave dynamics. Interface conditions are applied to ensure continuity by enforcing the conservation of volume flux and surface elevation matching between the two regions. The accuracy of this coupled numerical scheme is verified through convergence analysis, and its validity is established by comparing the simulation results with prior studies. Numerical experiments demonstrate the model’s capability to capture wave responses to simplified pressure disturbances and simulate wave propagation over intricate bathymetry. This computational framework offers an efficient and robust tool for analyzing nonlinear wave interactions with stationary ships or harbor structures. The methodology is specifically applied to examine the response of moored vessels to incident waves within Paradip Port, Odisha, India.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-13
DOI: 10.3390/jmse13030562
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 563: Impact of Coal-Fired Power Plants on Suspended
Sediment Concentrations in Coastal Waters
Authors: Zhi-Cheng Huang, Po-Chien Lin, Po-Hsun Lin, Shun-Hsing Chuang
First page: 563
Abstract: Many coastal coal-fired power plants utilize seawater flue gas desulfurization (SWFGD) systems, which may pose risks of heavy metal attachment on suspended sediments. Understanding variations in suspended sediment concentration (SSC) is therefore useful for controlling marine pollution. We studied two power plants as examples of discharging SSC using continuous measurement techniques. Monitoring sites at intake and discharge points and the surrounding coastal areas of the power plants was conducted across seasons. The first case study, Linkou Power Plant, is located in a high-SSC region influenced by monsoon winds and wave activity. Results indicate that SSC levels at all the monitoring sites are correlated with environmental factors of wind and wave conditions, with strong positive correlations observed between the intake and discharge points. In contrast, the Dalin Power Plant is located within an international harbor, where the SSC levels are generally low; however, sudden increases in SSC are observed at the intake point due to disturbances from vessel activities. These sudden increases are not evident at the discharge point, suggesting a sink of SSC may occur within the system. These results demonstrate that the two studied power plants have limited effects on the increase in SSC; the SSC in the discharge point is mainly related to the SSC input at the intake point. Effective management of SSC at the intake may help mitigate coastal pollution caused by SSC discharge and reduce the risk of harmful substances adhering to suspended solids in the discharging wastewater.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-14
DOI: 10.3390/jmse13030563
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 564: Multifactorial Controls on the Dongdaobei
Submarine Canyon System, Xisha Sea, South China Sea
Authors: Meijing Sun, Hongjun Chen, Chupeng Yang, Xiaosan Hu, Jie Liu
First page: 564
Abstract: The submarine canyons system is the most widely distributed geomorphic unit on the global continental margin. It is an important concept in the field of deep-water sedimentation and geohazards. Based on high-resolution multibeam bathymetry and two-dimensional seismic data, the dendritic canyon system north of Dongdao island is studied at the eastern Xisha area of the South China Sea. The Dongdaobei submarine canyon is distributed in water depths between 1000 and 3150 m. The main source area in the upper course of the canyon originates from the northwest of Dongdao platform and the Yongxing platform. The sediments from the source area are transported to the main canyon in the form of various gravity flows. Landslides on the slope significantly impact canyon evolution by delivering sediment to the canyon head and causing channel deflection through substrate failure and flow-path reorganization. A large number of pockmarks are distributed around the north slope of the main canyon. The small-scale channels, which are formed as a result of the continuous erosion of the pockmark chains, are connected to the canyon sidewalls. The seamounts are distributed along the south bank of the canyon, exerting a controlling influence on the directional changes in the main canyon’s downstream segment. The formation and evolution of the Dongdaobei submarine canyon are primarily influenced by several factors, including tectonic activity and inherited negative topography, erosion by sedimentary gravity flows, sediment instability, and the shielding effect of seamounts.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-14
DOI: 10.3390/jmse13030564
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 565: Deep Reinforcement Learning-Based Energy
Management Strategy for Green Ships Considering Photovoltaic Uncertainty
Authors: Yunxiang Zhao, Shuli Wen, Qiang Zhao, Bing Zhang, Yuqing Huang
First page: 565
Abstract: Owing to the global concern regarding fossil energy consumption and carbon emissions, the power supply for traditional diesel-driven ships is being replaced by low-carbon power sources, which include hydrogen energy generation and photovoltaic (PV) power generation. However, the uncertainty of shipboard PV power generation due to weather changes and ship motion variations has become an essential factor restricting the energy management of all-electric ships. In this paper, a deep reinforcement learning-based optimization algorithm is proposed for a green ship energy management system (EMS) coupled with hydrogen fuel cells (HFCs), lithium batteries, PV generation, an electric power propulsion system, and service loads. The focus of this study is reducing the total operation cost and improving energy efficiency by jointly optimizing power generation and voyage scheduling, considering shipboard PV uncertainty. To verify the effectiveness of the proposed method, real-world data for a hybrid hydrogen- and PV-driven ship are selected for conducting case studies under various sailing conditions. The numerical results demonstrate that, compared to those obtained with the Double DQN algorithm, the PPO algorithm, and the DDPG algorithm without considering the PV system, the proposed DDPG algorithm reduces the total economic cost by 1.36%, 0.96%, and 4.42%, while effectively allocating power between the hydrogen fuel cell and the lithium battery and considering the uncertainty of on-board PV generation. The proposed approach can reduce energy waste and enhance economic benefits, sustainability, and green energy utilization while satisfying the energy demand for all-electric ships.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-14
DOI: 10.3390/jmse13030565
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 566: Bivalves and Gastropods: Models for the Study of
Mucomics
Authors: Donatella Mentino, Carlotta De Blasi, Daniela Semeraro, Maria Mastrodonato, Marco Vito Guglielmi
First page: 566
Abstract: Mucomics is the study of mucus and its biochemical properties. This discipline has gained increasing attention due to the critical roles mucus plays in protection, adhesion, and communication across species. Ethical restrictions on vertebrate research have driven the interest in invertebrate models such as mollusks. Mollusks produce large amounts of mucus which has several functions, including immune defense, digestion, and environmental adaptation. Mollusks—terrestrial, freshwater, or marine—are valuable models for investigating mucus composition and its responses to environmental stressors, including heavy metal contamination. Histochemical and glycomic techniques have revealed variations in mucin glycosylation patterns that influence mucus functionality, such as its viscoelastic and adhesive properties. Bivalves and gastropods, widely used as bioindicators and generally not subject to regulatory constraints in experimental use, accumulate pollutants in their mucus, reflecting environmental health. Investigative techniques such as lectin histochemistry, proteomic, and glycomic analyses provide insights into the impact of contaminants on mucus composition. Further research on molluscan mucins can enhance understanding of their physiological roles, environmental interactions, and potential biomedical applications. By integrating molecular and histochemical approaches, mucomic studies offer a comprehensive perspective on mucus function, advancing both ecological monitoring and biotechnological applications.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-14
DOI: 10.3390/jmse13030566
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 567: A Novel Approach to Identify Technological
Innovation Opportunities Using Patent Mining for Floating Liquefied
Natural Gas Systems
Authors: Yu Lin, Haowen Zheng, Jackson Jinhong Mi, Yuanrui Li
First page: 567
Abstract: The floating liquefied natural gas (FLNG) system is an offshore facility that floats above a natural gas field, directly liquefying natural gas without the need for subsea pipelines. In recent years, there has been growing interest in exploring technological innovations for FLNG systems. As such, advancements could lead to breakthroughs in optimizing layout and operations within the limited space of these platforms. To address this, we first apply a patent mining method to cluster FLNG-related patent texts, identifying the key technological components. We then conduct a morphological analysis to pinpoint potential technological opportunities. In our case study, we identify seven such opportunities, which include a combination of plate-fin heat exchangers, horizontal LNG storage tanks, flexible flowlines, and tail loading methods. These findings offer valuable insights and directions for the future development of FLNG systems.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-14
DOI: 10.3390/jmse13030567
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 568: Layer-by-Layer Self-Assembly Marine Antifouling
Coating of Phenol Absorbed by Polyvinylpyrrolidone Anchored on Stainless
Steel Surfaces
Authors: Zaixiang Zheng, Shutong Wu, Haobo Shu, Qingzhen Han, Pan Cao
First page: 568
Abstract: Marine biofouling is a major problem that contributes to the failure of man-made marine structures. Conventional marine antifouling coatings that release heavy metal ions for antimicrobial purposes are no longer in line with today’s environmental issues. In this paper, a layer-by-layer (LBL) self-assembled marine antifouling coating based on an addition reaction between polyvinylpyrrolidone (PVP) and phenols to anchor pyrogallic (PG) with an antimicrobial effect on stainless steel surfaces is presented. For this purpose, three phenolics were selected, and their antifouling effects were compared. Field emission scanning electron microscopy, contact angle measurement, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy analysis (FTIR) were used to thoroughly characterize the LBLPGs, and the results showed superior homogeneity of the coatings with no significant delamination. Simulated marine antifouling and friction tests showed that the coating inhibited Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Phaeodactylum tricornutum (P. tricornutum) by more than 90% and reduced the friction coefficient of the stainless steel surface from 0.38 to 0.24, demonstrating superior antifouling and friction resistance effects.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-14
DOI: 10.3390/jmse13030568
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 569: Nutrient Fluxes from the Kamchatka and Penzhina
Rivers and Their Impact on Coastal Ecosystems on Both Sides of the
Kamchatka Peninsula
Authors: Pavel Semkin, Galina Pavlova, Vyacheslav Lobanov, Kirill Baigubekov, Yuri Barabanshchikov, Sergey Gorin, Maria Shvetsova, Elena Shkirnikova, Olga Ulanova, Anna Ryumina, Ekaterina Lepskaya, Yuliya Fedorets, Yi Xu, Jing Zhang
First page: 569
Abstract: Catchment areas on volcanic territories in different regions are of great interest since they are enriched with nutrients that contribute significantly to coastal ecosystems. The Kamchatka Peninsula is one of the most active volcanic regions of the world; however, to date, the chemistry of its river waters and the state of its coastal ecosystems remain understudied in connection with volcanism. The two rivers under study are the largest in this region. The Kamchatka River, unlike the Penzhina River, drains volcanic territories, including the areas of the most active volcanoes of the Klyuchevskaya group of volcanoes and the Shiveluch Volcano. The mouth of the Kamchatka River has been shown to have DIP and DIN concentrations of 2.79–3.87 and 10.0–23.8 µM, respectively, during different seasons, which are comparable to rivers in urbanized areas with sewerage and agricultural sources of nutrients. It has been established that volcanoes form high concentrations of nutrients in the catchment area of the Kamchatka River. The Penzhina River has had very low DIP and DIN concentrations of 0.2–0.8 and 0.17–0.35 µM, respectively, near the mouth during different seasons, but high concentrations of DOC, at 5.9 mg/L in spring, which may be due to seasonal thawing of permafrost. During the period of increasing river discharge, seasonal phytoplankton blooms occur in spring and summer in bays of the same name, as shown using satellite data. The biomass of zooplankton in Penzhina Bay is at a level of 100 mg/L, while in Kamchatka Gulf, it exceeds 2000 mg/L. Thus, the biomass of zooplankton in the receiving basin, which is influenced by the runoff of the Kamchatka River with a volcanic catchment area in eastern Kamchatka, is 20 times higher than in the basin, which has a small nutrient flux with the river runoff in northwestern Kamchatka. This study demonstrates the connection between nutrient fluxes from a catchment area and the formation of seasonal phytoplankton blooms and high zooplankton biomass in the coastal area. We also study seasonal, year-to-year, and climatic variability of water discharges and hydrometeorological conditions to understand how nutrient fluxes can change in the foreseeable future and influence coastal ecosystems.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-14
DOI: 10.3390/jmse13030569
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 570: The Application of a Joint Distribution of
Significant Wave Heights and Peak Wave Periods in the Northwestern South
China Sea
Authors: Gongpeng Liu, Qunan Ouyang, Zhanyuan He, Na Zhang
First page: 570
Abstract: A joint distribution of significant wave heights (Hs) and peak wave periods (Tp) in the northwestern South China Sea is created using a conditional distribution model in this work. An unstructured triangular mesh wave model covering the northwestern South China Sea is established based on the third-generation spectral wave model SWAN. This wave model has been extensively validated against field data and was run from 1979 to 2020 to generate long enough one-hourly Hs and Tp. Four probability density functions including Normal, Lognormal, Gamma and 3P Weibull distributions are adopted to construct the marginal independent distribution of Hs. The results show that the 3P Weibull distribution is more suitable in fitting the marginal distribution of Hs compared to the other three distributions. Three combinations of dependence functions (μ and σ), namely, power3 and exp3, insquare2 and asymdecrease3, and logistics4 and alpha3, are used to create the Normal and Lognormal distributions for Tp. The estimations of dependence functions and corresponding fitted Tp demonstrate that the μ and σ using power3 and exp3 perform best in producing the conditional distribution of Tp. In addition, the environmental contours derived by an IFORM are used to generate the extreme sea states with return periods of 1, 5, 10, 25, 50 and 100 years.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-14
DOI: 10.3390/jmse13030570
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 571: A Novel Autonomous Marine Profile Elements
Monitoring and Sample Collection System
Authors: Yuxiang He, Wei Fan, Xiaoya Zang, Zhiyu Zou, Shicheng Hu, Yonggang Zhao
First page: 571
Abstract: This study develops an autonomous ocean observation system designed for continuous, multidimensional marine parameter monitoring. The system integrates sensor-based monitoring and sample collection capabilities, utilizing tidal energy to facilitate vertical movement within the water column (0–50 m). The system combines tidal energy utilization with a buoyancy regulation unit, significantly reducing reliance on conventional battery power while maintaining the system’s flexibility in deep control, demonstrating superior energy efficiency compared to traditional platforms. The combination of sensor monitoring and sample acquisition enables real-time acquisition of oceanographic parameters (e.g., temperature, salinity, chlorophyll) and on-demand water sample collection for high-precision laboratory analysis. Laboratory and sea trials validated its ability to perform reciprocating vertical motion, autonomous buoyancy regulation, and leak-free sample collection, confirming feasibility for long-term coastal ecosystem monitoring. This study highlights the potential of autonomous systems for sustainable ocean observation and environmental monitoring.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-14
DOI: 10.3390/jmse13030571
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 572: Sea Surface Floating Small-Target Detection
Based on Dual-Feature Images and Improved MobileViT
Authors: Yang Liu, Hongyan Xing, Tianhao Hou
First page: 572
Abstract: Small-target detection in sea clutter is a key challenge in marine radar surveillance, crucial for maritime safety and target identification. This study addresses the challenge of weak feature representation in one-dimensional (1D) sea clutter time-series analysis and suboptimal detection performance for sea surface small targets. A novel dual-feature image detection method incorporating an improved mobile vision transformer (MobileViT) network is proposed to overcome these limitations. The method converts 1D sea clutter signals into two-dimensional (2D) fused images by means of a Gramian angular difference field (GADF) and recurrence plot (RP), enhancing the model’s key-information extraction. The improved MobileViT architecture enhances detection capabilities through multi-scale feature fusion with local–global information interaction, integration of coordinate attention (CA) for directional spatial feature enhancement, and replacement of ReLU6 with SiLU activation in MobileNetV2 (MV2) modules to boost nonlinear representation. Experimental results on the IPIX dataset demonstrate that dual-feature images outperform single-feature images in detection under a 10−3 constant false-alarm rate (FAR) condition. The improved MobileViT attains 98.6% detection accuracy across all polarization modes, significantly surpassing other advanced methods. This study provides a new paradigm for time-series radar signal analysis through image-based deep learning fusion.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-14
DOI: 10.3390/jmse13030572
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 573: Uncertainty Analysis of Overflow Due to Sea Dike
Failure During Typhoon Events
Authors: Wei-Che Huang, Wen-Cheng Liu, Hong-Ming Liu
First page: 573
Abstract: Taiwan is frequently affected by typhoons, which cause storm surges and wave impacts that damage sea dikes, resulting in overflow and subsequent flooding. Therefore, it is essential to analyze the damage to sea dikes caused by storm surges and wave impacts, leading to overflow, for effective coastal protection. This study employs the ADCIRC model coupled with the SWAN model to simulate storm surges and waves around Taiwan and develops a sea dike failure model that incorporates mechanisms for impact damage, run-up damage, and overflow calculation. To ensure model accuracy, three historical typhoon events were used for calibration and validation of the ADCIRC+SWAN model. The results show that the ADCIRC coupled with SWAN model can effectively simulate storm surges and waves during typhoons. Typhoon Soulik (2013) was simulated to examine a breach in the Tamsui Youchekou sea dike in northern Taiwan, and an uncertainty analysis was conducted using the Monte Carlo method and Bayesian theorem. The results indicate that when the compressive strength of the sea dike is reduced to 5% of its original strength, impact and run-up damage occur, leading to overflow. In the case of impact damage, the overflow volume due to the breach falls within a 95% confidence interval of 0.16 × 106 m3 to 130 × 106 m3. For run-up damage, the 95% confidence interval for the overflow volume ranges from 0.16 × 106 m3 to 639 × 106 m3. The ADCIRC+SWAN model is used to simulate storm surge and waves, incorporating impact damage and run-up damage mechanisms to represent concrete sea dike failure. This approach effectively models dike failure and calculates the resulting overflow.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-14
DOI: 10.3390/jmse13030573
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 574: Application of Microbial Technology for
Enhancing Carbon Dioxide Geosequestration in Shallow Seabed Caprock
Authors: Liang Xiong, Lieyu Tian, Xiaolian Zhang, Yang Lv, Huiyin Zhang
First page: 574
Abstract: The utilization of fossil fuels releases a large amount of carbon dioxide (CO2) gas, leading to global temperature changes and climate warming. Carbon dioxide geological sequestration (CCS) is an effective solution, including the use of shallow seabed hydrate reservoirs as a geological sink. However, the sealing and strength of the caprock affect the sequestration effectiveness. Therefore, this study assessed the strength and sealing properties of a shallow seabed layer reinforced with Microbial-induced Carbonate Precipitation (MICP) technology through a combination of triaxial tests and X-ray CT. In addition, carbon dioxide sequestration experiments were conducted to investigate the factors influencing the ability of MICP technology to accelerate the mineralization and sequestration of carbon dioxide. The results demonstrate that MICP technology can enhance the sealing capacity of caprock by increasing its strength, reducing its porosity, and accelerating CO2 mineralization. After 120 h of treatment, the CO2 concentration in the air decreased from 887 ppm to 310 ppm, showing a significant mineralization effect. The bacteria used, Bacillus megaterium, can simultaneously secrete urease and carbonic anhydrase (CA). During the urease hydrolysis of urea, this not only increases the rate of calcium carbonate formation and improves the sealing performance but also accelerates the catalytic mineralization of CO2 by carbonic anhydrase by creating an alkaline environment.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-14
DOI: 10.3390/jmse13030574
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 575: Ship Mooring Methodology Designed for Ship
Berthing in Extremely Limited Conditions
Authors: Vytautas Paulauskas, Donatas Paulauskas
First page: 575
Abstract: In some ports, there are separate very narrow places between the quays and other navigational obstacles, where the distance between the quays or between the quays and navigational obstacles is very small. Narrow gaps or channels in the water area, where quays are built and ships are berthing, make it difficult for ships to berth at such quays. Accurate knowledge of a ship’s manoeuvrability characteristics, combined with the application of these characteristics in berthing operations and the optimal use of tugboat capabilities, allows for better utilization of restricted port spaces. The article presents a developed ship berthing methodology designed for ship berthing in extremely limited conditions, utilizing the ship’s manoeuvrability capabilities and maximizing the capabilities of tugboats when mooring ships in extremely limited conditions. The developed methodology was tested with real ships and tugboats in specific port conditions and using calibrated simulators, and the results of the experimental research and theoretical calculations are presented in the article as a case study. The research results (methodology) obtained and presented in the article can be applied to any ships and ports, precisely adapting them to specific port situations. The article studies ship manoeuvrability and tugboat capabilities under various hydrometeorological and hydrological conditions, assesses the impact of shallow depths (shallowness), and determines the boundary conditions for ship berthing.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-15
DOI: 10.3390/jmse13030575
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 576: Facies-Controlled Sedimentary Distribution and
Hydrocarbon Control of Lower Cretaceous Source Rocks in the Northern
Persian Gulf
Authors: Yaning Wang, Wei Huang, Tao Cheng, Xuan Chen, Qinqin Cong, Jianhao Liang
First page: 576
Abstract: The two-phase source rocks deposited during the Lower Cretaceous in the Persian Gulf Basin play a pivotal role in the regional hydrocarbon system. However, previous studies have lacked a macroscopic perspective constrained by the Tethyan Ocean context, which has limited a deeper understanding of their developmental patterns and hydrocarbon control mechanisms. To address this issue, this study aims to clarify the spatiotemporal evolution of the two-phase source rocks and their hydrocarbon control effects, with a particular emphasis on the critical impact of terrestrial input on the quality improvement of source rocks. Unlike previous studies that relied on a single research method, this study employed a comprehensive approach, including time series analysis, sequence stratigraphy, lithofacies, well logging, well correlation, seismic data, and geochemical analysis, to systematically compare and analyze the depositional periods, distribution, and characteristics of the two-phase source rocks under different sedimentary facies in the region. The goal was to reveal the intrinsic relationship between the Neo-Tethyan Ocean context and regional sedimentary responses. The results indicate the following: (1) the late Tithonian–Berriasian and Aptian–Albian source rocks in the Northern Persian Gulf were deposited during periods of extensive marine transgression, closely aligning with the global Weissert and OAE1d anoxic events, reflecting the profound impact of global environmental changes on regional sedimentary processes; (2) in the early stages of the Neo-Tethyan Ocean, controlled by residual topography, the Late Tithonian–Berriasian source rocks exhibited a shelf–intrashelf basin facies association, with the intrashelf basin showing higher TOC, lower HI, and higher Ro values compared to the deep shelf facies, indicating more favorable conditions for organic matter enrichment; (3) with the opening and deepening of the Neo-Tethyan Ocean, the Aptian–Albian source rocks at the end of the Lower Cretaceous transitioned to a shelf–basin facies association, with the basin facies showing superior organic matter characteristics compared to the shelf facies; (4) the organic matter content, type, and thermal maturity of the two-phase source rocks are primarily controlled by sedimentary facies and terrestrial input, with the Aptian–Albian source rocks in areas with terrestrial input showing significantly better quality than those without, confirming the decisive role of terrestrial input in improving source rock quality. In summary, this study not only reveals the differences in the depositional environments and hydrocarbon control mechanisms of the two-phase source rocks, but also highlights the core role of terrestrial input in enhancing source rock quality. The findings provide a basis for facies selection in deep natural gas exploration in the Zagros Belt and shale oil exploration in the western Rub’ al-Khali Basin, offering systematic theoretical guidance and practical insights for hydrocarbon exploration in the Persian Gulf and broader tectonic domains.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-15
DOI: 10.3390/jmse13030576
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 577: Variability in Diurnal Internal Tides and
Near-Inertial Waves in the Southern South China Sea Based on Mooring
Observations
Authors: Yilin Zhang, Yifan Wang, Chen Wang, Shoude Guan, Wei Zhao
First page: 577
Abstract: Temporal variations in diurnal internal tides (ITs) and near-inertial waves (NIWs) in the southern South China Sea (SCS) are characterized, based on two 13-month moored current observations. Diurnal ITs, dominated by O1 and K1, are found to exhibit spring–neap cycles of about 14 days and significant seasonal variations. The incoherent components explain 54% and 56% of the total energy in the diurnal band, which further complicates its temporal variabilities. As for NIWs, wind energy input serves as the primary energy source and three strong events are observed. Tropical cyclone RAI passed through two moorings during the event 1 period, and triggered a peak near-inertial kinetic energy of 19.55 J m−3 (18.82 J m−3) at two moorings. After generation, the NIWs propagated downward to around 300 m, becoming the most intense event observed at DA2. In contrast, the NIWs response to tropical cyclone NOCK’s passage during event 3 was relatively weaker. The near-inertial KE generated by NOCK was confined to depths shallower than 150 m, with the average near-inertial KE being only 85% (52%) of that during event 1 for two moorings, despite the near-inertial energy input from NOCK being nearly 400% that of RAI. The modulation of background vorticity is considered the primary factor resulting in the difference in intensity of two NIW events. The penetrating depth of NIWs under the modulation of anticyclonic eddies was more than twice that under the cyclonic eddies. Furthermore, the strongest NIWs during event 2 that were observed below 350 m at mooring 2 (183% stronger than average) were also related to a strong anticyclonic eddy.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-15
DOI: 10.3390/jmse13030577
Issue No: Vol. 13, No. 3 (2025)
- JMSE, Vol. 13, Pages 578: Investigation on the Welding Residual Stress
Distribution in Multi-Segment Conical Egg-Shaped Shell
Authors: Yongmei Zhu, Longbo Zhou, Ao Sun, Lihui Wang, Xilu Zhao
First page: 578
Abstract: The egg-shaped pressure shell, an essential component of manned submersibles, has garnered significant attention from researchers. However, the fabrication of such shells, particularly the welding process used to connect petals or frustums into a shell blank, has raised several concerns. This study investigates the distribution of welding residual stresses in a multi-segment frustum-assembled egg-shaped shell using a thermal–elastic–plastic method under an instantaneous heat source. A numerical model for a 12-segment frustum-welded egg-shaped shell is developed, and welding simulations are performed. The model’s boundary conditions are defined by cyclic symmetry, with a mesh element size of 2 mm to enhance computational efficiency. The results are validated through experimental tests. The findings indicate that the residual stress around the weld is tensile, while compressive stress is present on both sides of the weld. The length of the generatrix and the relative inclination angle significantly affect the distribution and overlap of circumferential residual stress, whereas axial residual stress primarily influences its magnitude. Finally, a simplified numerical model of the egg-shaped shell is proposed, with its simulation results showing good agreement with the distribution of welding residual stresses on the shell surface. This study provides valuable insights for optimizing the welding process of egg-shaped pressure shells in manned submersibles.
Citation: Journal of Marine Science and Engineering
PubDate: 2025-03-15
DOI: 10.3390/jmse13030578
Issue No: Vol. 13, No. 3 (2025)
