Subjects -> EARTH SCIENCES (Total: 771 journals)
    - EARTH SCIENCES (527 journals)
    - GEOLOGY (94 journals)
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    - OCEANOGRAPHY (88 journals)

OCEANOGRAPHY (88 journals)

Showing 1 - 79 of 79 Journals sorted by number of followers
Deep Sea Research Part II: Topical Studies in Oceanography     Hybrid Journal   (Followers: 28)
Hydrobiology     Open Access   (Followers: 28)
Estuaries and Coasts     Hybrid Journal   (Followers: 25)
Limnology and Oceanography     Hybrid Journal   (Followers: 25)
Deep Sea Research Part I : Oceanographic Research Papers     Hybrid Journal   (Followers: 23)
Journal of Physical Oceanography     Hybrid Journal   (Followers: 21)
Frontiers in Marine Science     Open Access   (Followers: 20)
New Zealand Journal of Marine and Freshwater Research     Hybrid Journal   (Followers: 19)
Journal of Marine Biology & Oceanography     Hybrid Journal   (Followers: 19)
Progress in Oceanography     Hybrid Journal   (Followers: 18)
Journal of Marine Sciences     Open Access   (Followers: 18)
Coastal Engineering     Hybrid Journal   (Followers: 16)
Advances in Oceanography and Limnology     Open Access   (Followers: 16)
Maritime Studies     Open Access   (Followers: 13)
Journal of Oceanography     Hybrid Journal   (Followers: 12)
Advances in Statistical Climatology, Meteorology and Oceanography     Open Access   (Followers: 10)
Bulletin of Marine Science     Full-text available via subscription   (Followers: 9)
Atmospheric and Oceanic Science Letters     Open Access   (Followers: 9)
Fisheries Oceanography     Hybrid Journal   (Followers: 8)
International Journal of Oceanography     Open Access   (Followers: 8)
Physical Oceanography     Hybrid Journal   (Followers: 6)
Open Journal of Marine Science     Open Access   (Followers: 6)
Limnology and Oceanography: Fluids and Environments     Full-text available via subscription   (Followers: 6)
Journal of Oceanography and Marine Science     Open Access   (Followers: 6)
Oceanography : Open Access     Open Access   (Followers: 6)
Limnology and Oceanography: Methods     Hybrid Journal   (Followers: 6)
Paleoceanography and Paleoclimatology     Full-text available via subscription   (Followers: 5)
Marine Science     Open Access   (Followers: 5)
Journal of Oceanology and Limnology     Hybrid Journal   (Followers: 4)
Journal of Marine Science and Engineering     Open Access   (Followers: 4)
Ocean Yearbook Online     Hybrid Journal   (Followers: 4)
Limnology and Oceanography Letters     Open Access   (Followers: 4)
African Journal of Marine Science     Hybrid Journal   (Followers: 3)
Journal of Marine Science and Application     Hybrid Journal   (Followers: 3)
Oceanology     Hybrid Journal   (Followers: 3)
Journal of Operational Oceanography     Hybrid Journal   (Followers: 3)
Journal of Coastal Development     Open Access   (Followers: 3)
Ciencias Marinas     Open Access   (Followers: 3)
Journal of Aquatic Sciences     Full-text available via subscription   (Followers: 3)
Journal of Ocean Engineering and Marine Energy     Hybrid Journal   (Followers: 3)
Limnology and Oceanography e-Lectures     Open Access   (Followers: 3)
Development and Applications of Oceanic Engineering     Open Access   (Followers: 2)
Indian Journal of Geo-Marine Sciences     Open Access   (Followers: 2)
Regional Studies in Marine Science     Hybrid Journal   (Followers: 2)
Limnology and Oceanography: Bulletin     Hybrid Journal   (Followers: 2)
Mediterranean Marine Science     Open Access   (Followers: 2)
Annals of Marine Science     Open Access   (Followers: 2)
Annals of Limnology and Oceanography     Open Access   (Followers: 2)
Journal of Ocean University of China (English Edition)     Hybrid Journal   (Followers: 1)
Scientia Marina     Open Access   (Followers: 1)
Western Indian Ocean Journal of Marine Science     Open Access   (Followers: 1)
Marine Technology Society Journal     Full-text available via subscription   (Followers: 1)
Journal of Ocean Engineering and Science     Open Access   (Followers: 1)
Ocean Life     Open Access   (Followers: 1)
Acta Aquatica : Aquatic Sciences Journal     Open Access   (Followers: 1)
Journal of Ocean Engineering and Technology     Open Access   (Followers: 1)
Tropical Oceanography     Open Access   (Followers: 1)
Marine Systems & Ocean Technology     Hybrid Journal   (Followers: 1)
Marine Life Science & Technology     Hybrid Journal   (Followers: 1)
Coastal Engineering Proceedings : Proceedings of the International Conference on Coastal Engineering     Open Access   (Followers: 1)
Asian Journal of Fisheries and Aquatic Research     Open Access  
Thalassas : An International Journal of Marine Sciences     Hybrid Journal  
Oceans     Open Access  
Aquatic Research     Open Access  
Jurnal Kelautan Tropis     Open Access  
Depik Jurnal Ilmu-Ilmu Perairan, Pesisir dan Perikanan     Open Access  
Journal of Agricultural and Marine Sciences     Open Access  
Turkish Journal of Maritime and Marine Sciences     Open Access  
Arquivos de Ciências do Mar     Open Access  
Scientific Drilling     Open Access  
Jurnal Kelautan : Indonesian Journal of Marine Science and Technology     Open Access  
Oceanologia     Open Access  
Revista de Gestão Costeira Integrada     Open Access  
Revista Ciencias Marinas y Costeras     Open Access  
Egyptian Journal of Aquatic Research     Open Access  
China Ocean Engineering     Hybrid Journal  
Revista de Biología Marina y Oceanografía     Open Access  
Latin American Journal of Aquatic Research     Open Access  
Acta Oceanologica Sinica     Hybrid Journal  
Similar Journals
Journal Cover
Journal of Marine Science and Engineering
Number of Followers: 4  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2077-1312
Published by MDPI Homepage  [258 journals]
  • JMSE, Vol. 12, Pages 361: Structural Features and Phylogenetic
           Implications of Crinoid Echinoderms Based on Thirteen Novel Mitochondrial
           Genomes

    • Authors: Qinzeng Xu, Min Lu, Yuyao Sun, Zhong Li, Yixuan Li, Yue Dong, Xuying Hu, Qian Zhang, Bing Liu, Xuebao He
      First page: 361
      Abstract: Crinoids, as integral echinoderms, play a crucial ecological role in benthic communities, serving as significant indicators reflecting the health of marine ecosystems. However, the phylogenetic relationships within crinoids are unclear. More molecular data can help to facilitate biodiversity assessment and elucidate evolutionary relationships by the phylogenetic tree. In this study, 13 complete mitochondrial genomes of the Crinoidea class were sequenced, annotated, and compared with other same class species available on NCBI. The results reveal five different gene order patterns among these mitochondrial genomes, indicating that crinoids have undergone gene rearrangements during evolution. The complete mitochondrial genome length of crinoids ranges from 15,772 bp to 16,850 bp. High A + T content, ranging from 64.5% to 74.2%, was observed. Additionally, our analysis of protein-coding genes highlights a preference for A + T nucleotides, along with specific start and stop codon usage, offering insights into codon bias and its implications for protein synthesis and function. The phylogenetic topology shows that the stalkless crinoid and stalked crinoid are distinct, and the phylogenetic trees generated based on maximum likelihood and Bayesian inference are almost identical at the family and order topology levels. The phylogenetic relationships of each family were fully clarified in four orders. A total of eleven positive selection sites were detected within six genes: cytb, nad2, nad3, nad4, nad4L and nad5. This study reveals the phylogenetic relationships of crinoid species, the mitochondrial gene differences, and the selective pressure on the evolution of stalked crinoids. This study significantly enhanced the crinoid mitochondrial genome database and contributed to a better understanding of the phylogenetic relationships among crinoid echinoderms.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-20
      DOI: 10.3390/jmse12030361
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 362: Dynamic Positioning Control for Marine Crafts: A
           Survey and Recent Advances

    • Authors: Xiaoyang Gao, Tieshan Li
      First page: 362
      Abstract: This paper surveys the recent advances in dynamic positioning (DP) control for marine crafts. DP of marine crafts means that a craft can maintain a fixed position and heading, or move along a predetermined trajectory slowly without the anchoring system, using only its own thruster system to counteract ocean disturbances. The survey is by no means exhaustive but provides a survey of some of the major technological advancements in DP controller design over the years of research and development. Firstly, the model of marine crafts and some difficult problems in DP control are introduced including the impact of multiple source disturbance, unavailable velocity measurement information, resource conservation and performance optimization, destabilizing impact of faults and network security and compound multi-constraint restrictions. Then, the DP control schemes in recent years are summarized and classified in detail. Finally, some theoretical and technical problems are proposed, including online data-driven model-free control, man–machine combination intelligent control and composite hierarchical anti-disturbance control to guide future investigations.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-20
      DOI: 10.3390/jmse12030362
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 363: Distributed Lyapunov-Based Model Predictive
           Control for AUV Formation Systems with Multiple Constraints

    • Authors: Zheping Yan, Mingyao Zhang, Jiajia Zhou, Lidong Yue
      First page: 363
      Abstract: This paper focuses on the formation tracking issue of autonomous underwater vehicles (AUVs) subject to multiple constraints in three-dimensional space. We developed a novel distributed Lyapunov-based model predictive controller (DLMPC) with a fast finite-time extended state observer (FFTESO). Initially, the external disturbances and internal uncertainties of each AUV were precisely compensated using the designed FFTESO. Subsequently, we proposed DLMPC-based position tracking and velocity tracking controllers, which solved an online optimization problem to determine optimal velocities and control forces. This hierarchical framework effectively managed system constraints, such as state constraints and actuator saturation. Additionally, the Lyapunov-based backstepping control law was applied to construct stability constraints in the distributed optimization problem, ensuring the recursive feasibility and closed-loop system stability of the proposed scheme. Sufficient conditions and attraction regions to ensure stability were explicitly provided. Finally, the simulation results demonstrated that the proposed method improved both the convergence speed and tracking accuracy by at least 30% compared to other methods.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-20
      DOI: 10.3390/jmse12030363
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 364: Study of the Formation of Hydrates with NaCl,
           Methanol Additive, and Quartz Sand Particles

    • Authors: Yaqiang Qi, Yonghai Gao, Lei Zhang, Xinyao Su, Yanli Guo
      First page: 364
      Abstract: During deepwater drilling, testing, production, or hydrate mining, the circulating medium in the wellbore may contain solid particles, such as rock chips and sand, in addition to drilling fluids, gas, and water. In the high-pressure, low-temperature conditions of deep water, gas intrusion can easily combine with free water in the drilling fluid to form hydrates, increasing the drilling risk. Therefore, understanding the formation patterns of hydrates in drilling fluids is of significant importance for the prevention and control of hydrates. This study utilized a small-scale high-pressure reactor to investigate the impact of the stirring rate, NaCl, and methanol additives, as well as the sand content on the hydrate formation process and gas consumption. The results indicate that the hydrate formation process can be divided into an induction stage, a rapid formation stage, and a slow formation stage. The induction stage and rapid formation stage durations are significantly reduced under stirring conditions. In NaCl and methanol solutions, hydrate formation is inhibited, with the induction stage duration increasing with higher concentrations of NaCl and methanol. There was no apparent rapid formation stage observed. The final gas consumption decreases substantially with increasing concentrations of NaCl and methanol, reaching no significant hydrate formation at a 20% concentration. The sand content has a significant impact on the slow formation stage, with the final gas consumption increasing within a certain range (in this work, at a sand content of 20%), and being notably higher than in the pure water system under the same conditions.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-21
      DOI: 10.3390/jmse12030364
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 365: Numerical Evaluation of Commingled Production
           Potential of Marine Multilayered Gas Hydrate Reservoirs Using Fractured
           Horizontal Wells and Thermal Fluid Injection

    • Authors: Shuaishuai Nie, Jiangfei Li, Ke Liu, Xiuping Zhong, Yafei Wang
      First page: 365
      Abstract: Multilayered reservoirs with coexisting free gas and hydrates are primary targets for commercialization, nevertheless, the extremely low permeability greatly limits their extraction efficiency. Herein, multilayer commingled production using horizontal wells stimulated by hydraulic fracturing and thermal fluid injection was proposed to enhance productivity, and the effects of key factors on co-production performance were numerically examined, with the reservoir located in the Shenhu Area as the geological background. The results indicated that due to severe interlayer contradictions, the stimulation capabilities of using fracturing or thermal fluid injection alone were limited, in particular, the extraction of hydrates severely lagged behind. However, their combination exhibited tantalizing productivity due to strengthened inter-well interaction. Reducing the fracture spacing was more effective than increasing fracture conductivity in shortening the production cycle, and intensive fractures with adequate flow capacity were suggested for gas enhancement and water control. When the fracture spacing was reduced from 30 to 5 m and the fracture conductivity increased from 10 to 100 D·cm, the horizontal section length for commercial production (average daily gas production of 50,000 m3 and recovery ratio of 0.7) was reduced from 1758 to 146 m, which is lower than the on-site horizontal section length of 250–300 m. Therefore, the proposed development mode is promising for the commingled production of gas and hydrates.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-21
      DOI: 10.3390/jmse12030365
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 366: A Terrain-Following Control Method for
           Autonomous Underwater Vehicles with Single-Beam Sensor Configuration

    • Authors: Zheping Yan, Lichao Hao, Yuzhu Wang, Tao Chen
      First page: 366
      Abstract: This paper investigates the terrain-following problem for an autonomous underwater vehicle (AUV) from control perspectives with full consideration of terrain characteristics. By equipping the AUV with three simple single-beam echo sounders, a set of precise along-track bottom slopes are obtained in a real-time manner, and the occurrence of the lost bottom lock phenomenon caused by a single sonar altimeter is eliminated. A slope-based data processing method is developed, which enables an AUV to characterize seafloor features with complementary sensing modalities to generate proper adaptive height-modified values. In order to keep a fixed height when maneuvering over rugged terrains, a back-stepping depth control is implemented by adjusting horizontal rudder angle, and Lyapunov theory is adopted to analyze the asymptotic stability of the resulting terrain-following control system. At last, simulation results indicate the feasibility and effectiveness of the proposed methodology with a discussion of various sensor configurations.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-21
      DOI: 10.3390/jmse12030366
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 367: Analysis of Fluid Field in Fish Tank of Breeding
           Vessel with Perforated Broadsides under Wave Conditions

    • Authors: Wenhua Wang, Min Li, Guoqiang Fan, Kedong Zhang, Yi Huang
      First page: 367
      Abstract: For a fish tank of breeding vessels with perforated broadsides, in order to analyze its fluid characteristics under wave conditions, this paper presents a numerical method and predicts the fluid field in a fish tank with opening holes. Therein, three critical problems were solved, which include wave generation, the fluid–structure interaction of waves and vessel motion, and the sloshing phenomenon in the tank. The feasibility of the method was validated through a comparison with theoretical and experimental results. On this basis, the fluid characteristics in the fish tank of a fixed breeding vessel with opening holes on side walls were discussed. Firstly, the effects of wave direction, wave height, and wave period on the flow field in the tank were mainly analyzed. Next, the fluid characteristics in the tank of a floating vessel with opening holes equipping a multi-point mooring system were investigated. Finally, the influence of motion responses of breeding vessels on the fluid field in the fish tank was examined.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-21
      DOI: 10.3390/jmse12030367
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 368: Essential and Non-Essential Elemental
           Composition and Health Risks in Pacific Sardine in the Northwest Pacific
           Ocean

    • Authors: Tiantian Leng, Bilin Liu, Jingqian Xie, Leilei Zou, Dongqi Lu
      First page: 368
      Abstract: Pacific sardine (Sardinops sagax) in the northwest Pacific Ocean (NPO) not only preserve the equilibrium of the NPO food chain, but also serve as a source of nutrition for humans. In order to evaluate the levels of various elements in S. sagax, we collected specimens from NWP waters and ascertained the quantities of four macronutrients, nine essential trace elements, and twelve non-essential trace elements. The factors (fatness, sex, sexual maturity, body length, body weight, and age) influencing the concentration were investigated, and the correlations of trace elements were examined. Additionally, the Estimated Daily Intake (EDI) approach and the Target Hazard Quotient (THQ) methodology were used to assess contamination levels and associated consumption risks. The results revealed that the macronutrient content (54–10,500 mg kg−1) was higher than the necessary trace elements (0–488 mg kg−1) and the non-essential trace elements (0–448 mg kg−1), and most of the elements showed positive correlation with each other. Almost all of the element concentrations were below the maximum permitted levels (MPLs) recommended by the FAO/WHO, except for As and Cd. The factors, including fatness, sexual maturity, body length, body weight, and age, showed a negative correlation with most of the trace elements. The outcomes of the stepwise regression analysis showed that sex and stage of sexual maturation were the principal biological factors influencing elemental content. The risk assessment and standard dietary intake levels indicated that the potential health issues associated with the consumption of S. sagax were negligible.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-21
      DOI: 10.3390/jmse12030368
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 369: Numerical Simulation of Seakeeping Performance
           of a Barge Using Computational Fluid Dynamics (CFD)-Modified Potential
           (CMP) Model

    • Authors: Seol Nam, Jong-Chun Park, Jun-Bum Park, Hyeon Kyu Yoon
      First page: 369
      Abstract: This paper explains the evaluation process of seakeeping performance for small vessels using a CFD-modified potential (CMP) model, a hybrid simulation model that modifies the damping ratio with computational fluid dynamics (CFD) after analyzing ship motion based on the linear potential theory. From the result of the motion analysis using the CMP model, the seakeeping performance of a small vessel (a barge here) was evaluated on the basis of the single significant amplitude (SSA) under the sea states 2~4. The results of the motion RAOs and seakeeping performance evaluation were verified through comparison with the results obtained by performing model tests and potential flow programs only. In all sea states, the relative errors (compared to the experiment) of roll motion using the CMP model were relatively small compared to the results using the potential flow program and tended to decrease more as the sea state increased. On the other hand, the results of pitch motion using the CMP model were underestimated in all sea states compared to the experiment. However, it is seen that they are relatively closer to the experiment compared to the results using a potential flow program only.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-21
      DOI: 10.3390/jmse12030369
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 370: Microwave Drying Method before Sieving to Obtain
           Accuracy of Sand Size Parameters

    • Authors: Patricia Lopez-Garcia, Juan J. Muñoz-Perez, Antonio Contreras-de-Villar, Francisco Contreras-de-Villar, Jeanette Romero-Cozar, Pilar Diaz-Carrasco, Bismarck Jigena-Antelo
      First page: 370
      Abstract: The purpose of this study is to determine the differences between the size parameter findings, comparing the results of a muffle during a 12-h sand-drying process with those of a microwave, because the effectiveness of sand drying with a microwave has not previously been studied. To achieve the best outcomes and assess any inaccuracies, a technique was established. Several power levels and durations were used in the tests. Furthermore, as the median particle size (D50) affects the porosity of sand, samples from three beaches in the south of Spain with varying sand sizes were used in this study. When drying for at least 5 min, the error findings for D50 are less than 3.5%, which is perfectly acceptable for beach nourishment purposes. Regarding power, 462 watts was the optimal power; a lower power, approximately 300 watts, did not completely dry the material, even after nearly 15 min. Furthermore, errors in the sorting (σ) parameter were negligible. It is essential to implement the following recommendations in microwave drying methods: the use of a light and wide container for the sand, interruptions during drying, and a minimum duration of 5 min.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-22
      DOI: 10.3390/jmse12030370
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 371: Length–Weight and Body Condition
           Relationships of the Exploited Sea Cucumber Pearsonothuria graeffei

    • Authors: Alison R. Hammond, Steven W. Purcell
      First page: 371
      Abstract: Fishery stock assessments are often based on morphometric data from underwater diver surveys and landing surveys. Measurements of body length are usually converted to estimates of body weight, yet length–weight equations might differ among localities. We evaluated morphometric models for the sea cucumber, Pearsonothuria graeffei, collected at Lizard Island on the northern Great Barrier Reef, Australia, and explored differences in relative condition factor (Kn) across animal sizes. The estimation of body weight was compared among relationships with four different body size metrics: observed body length, SLW (square root of the body length–width product), recalculated body length (Le) from SLW, and body basal area. The basal area of the animals, the SLW index and Le provided more reliable estimations for body weight than using body length alone yet accounted for half of the variation in body weight. The length–weight relationship from animals at Lizard Island differed considerably from relationships published for the same species in New Caledonia and Philippines. Body condition was variable, and our model predicted a peak at 35 cm body length. Body metrics such as basal area, SLW index, and Le could offer more precise models for estimating the body weight of sea cucumbers for fishery purposes. Equations for estimating body weight from length and width of the sea cucumbers should be based on locality-specific data because morphometric relationships are spatially variable.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-22
      DOI: 10.3390/jmse12030371
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 372: Optimizing Multi-Vessel Collision Avoidance
           Decision Making for Autonomous Surface Vessels: A COLREGs-Compliant Deep
           Reinforcement Learning Approach

    • Authors: Weidong Xie, Longhui Gang, Mingheng Zhang, Tong Liu, Zhixun Lan
      First page: 372
      Abstract: Automatic collision avoidance decision making for vessels is a critical challenge in the development of autonomous ships and has become a central point of research in the maritime safety domain. Effective and systematic collision avoidance strategies significantly reduce the risk of vessel collisions, ensuring safe navigation. This study develops a multi-vessel automatic collision avoidance decision-making method based on deep reinforcement learning (DRL) and establishes a vessel behavior decision model. When designing the reward function for continuous action spaces, the criteria of the “Convention on the International Regulations for Preventing Collisions at Sea” (COLREGs) were adhered to, taking into account the vessel’s collision risk under various encounter situations, real-world navigation practices, and navigational complexities. Furthermore, to enable the algorithm to precisely differentiate between collision avoidance and the navigation resumption phase in varied vessel encounter situations, this paper incorporated “collision avoidance decision making” and “course recovery decision making” as state parameters in the state set design, from which the respective objective functions were defined. To further enhance the algorithm’s performance, techniques such as behavior cloning, residual networks, and CPU-GPU dual-core parallel processing modules were integrated. Through simulation experiments in the enhanced Imazu training environment, the practicality of the method, taking into account the effects of wind and ocean currents, was corroborated. The results demonstrate that the proposed algorithm can perform effective collision avoidance decision making in a range of vessel encounter situations, indicating its efficiency and robust generalization capabilities.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-22
      DOI: 10.3390/jmse12030372
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 373: Wave-Induced Instantaneous Liquefaction of a
           Non-Cohesive Seabed around Buried Pipelines: A Liquefaction-Associated
           Non-Darcy Flow Model Approach

    • Authors: Shichong Han, Mozhen Zhou, Dingli Zhang, Wengang Qi, Chaodong Xue, Qian Fang
      First page: 373
      Abstract: In complex marine environments, the wave-induced instantaneous liquefaction of the seabed is a key issue for the long-term safety control of marine structures. Existing computational frameworks for instantaneous liquefaction result in unreasonable tensile stresses in a non-cohesive seabed. To address this issue, a liquefaction-associated non-Darcy flow model has been proposed, but it has only been applied to the scenario of a pure seabed without a structure. In this study, we applied the previously proposed non-Darcy flow model to investigate the mechanism of wave–seabed–structure interactions under extreme wave loading considering a pipeline fully buried in a non-cohesive seabed. By comparing the liquefaction depths in the presence and absence of structures, it was found that the existence of structures weakens the attenuation of the pore pressure amplitude and influences the overall pore pressure distribution. Parametric studies were conducted. It was found that the liquefaction depth from the non-Darcy model is approximately 0.73 times that from the traditional Darcy model, regardless of whether or not a pipeline is involved. A quantitative relationship between the wave loading and structural size was established. The liquefied zone above the buried pipeline was found to be smaller than that in a pure seabed without a structure. A tentative explanation is provided for this phenomenon.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-22
      DOI: 10.3390/jmse12030373
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 374: Transient Tests for Checking the Trieste Subsea
           Pipeline: Toward Field Tests

    • Authors: Silvia Meniconi, Bruno Brunone, Lorenzo Tirello, Andrea Rubin, Marco Cifrodelli, Caterina Capponi
      First page: 374
      Abstract: Subsea pipelines are vital arteries transporting oil, gas, and water over long distances and play a critical role in the global resource supply chain. However, they are the most vulnerable to damage from both human-made and natural causes and are characterized by inherent inaccessibility. As a result, routine inspection and monitoring technologies, both reliable and at the lowest possible cost, are needed to ensure their longevity. To fill this need, the use of transient-test-based techniques is proposed. In this first paper of a set of two companion papers, attention is focused on the selection of the appropriate maneuver that generates pressure waves and then on the planned steps—i.e., the sequence of actions—functional to the execution of the transient tests in the best flow conditions for effective fault detection. A brief review of the available fault detection technologies with their limitations is also offered. Finally, the performance of the proposed procedure is evaluated mainly in terms of the stability of the pressure regime prior to the execution of the transient test.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-22
      DOI: 10.3390/jmse12030374
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 375: Ship Speed Optimization Method in Canal
           Environments Considering Waiting Times for Crossing Locks

    • Authors: Wen Xie, Sudong Xu, Nini Zhang, Jun Liu, Kai Yin, Liuyan Mao
      First page: 375
      Abstract: The shipping industry faces a pressing challenge with carbon emissions, prompting a focus on speed optimization for energy conservation and emission reduction. While much research has centered on optimizing speeds in oceans and rivers, canals have received less attention, despite their unique challenges of narrow waterways and busy locks. This study fills this gap by establishing a fuel consumption prediction model integrating key environmental factors such as water depth, width, and flow velocity. Drawing upon established methodologies in speed optimization, this study augments these models with waiting time limits for each canal segment. To validate the efficacy of the model, three representative ships are selected as case studies. The findings reveal a high predictive capability of the fuel consumption model, as evidenced by R2 values exceeding 0.97 across all cases. Notably, the optimization approach yields a fuel consumption reduction ranging from 4% to 5% for short waiting times. Furthermore, compared to conventional methods, the proposed optimization strategy achieves an 8.19% enhancement in fuel consumption and carbon emission reduction for long waiting times, culminating in an overall optimization rate of 11.54%. These results underscore the significance of employing the proposed speed optimization methodology, particularly during peak periods of canal congestion.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-22
      DOI: 10.3390/jmse12030375
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 376: Energy-Aware Integrated Scheduling for Quay
           Crane and IGV in Automated Container Terminal

    • Authors: Yuedi Luo, Xiaolei Liang, Yu Zhang, Kexin Tang, Wenting Li
      First page: 376
      Abstract: In this study, we address the integrated scheduling problem involving quay cranes and IGVs in automated terminals. We construct a mixed-integer planning model with the aim of minimizing the total energy consumption during quay crane and IGV operations, focusing on the loading-operation mode. The model considers the impact of the actual stowage of container ships on the loading order. We propose a dimension-by-dimension mutation sparrow search algorithm to optimize the model’s solution quality. Building upon the standard sparrow search algorithm, we incorporate cat mapping to enhance the diversity of the initial sparrow population. To improve global search in the early stage and local search in the later stage of the algorithm, we introduce an adaptive t-distribution mutation strategy. Finally, a total of 12 instances with container counts containing 30, 100, and 250 were designed for experiments to validate the effectiveness of the model and algorithm. The experiments demonstrate that, by appropriately increasing the number of quay cranes, configuring more than two or three IGVs can achieve optimal energy consumption for overall operations.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-22
      DOI: 10.3390/jmse12030376
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 377: An Overview on Structural Health Monitoring and
           Fault Diagnosis of Offshore Wind Turbine Support Structures

    • Authors: Yang Yang, Fayun Liang, Qingxin Zhu, Hao Zhang
      First page: 377
      Abstract: The service environment of offshore wind turbine (OWT) support structures is harsh, and it is extremely difficult to replace these structures during their operational lifespan, making their failure a catastrophic event. The structural health monitoring (SHM) of OWT support structures is a crucial aspect of operational maintenance for OWT support structures, aiming to mitigate significant financial losses. This paper systematically summarizes the current monitoring methods and technologies for OWT support structures, including towers and foundations. Through the review of monitoring content and the evolution of monitoring techniques for supporting structures, it delves deeper into the challenges faced by wind turbine monitoring and highlights potential avenues for future development. Then, the current damage identification techniques for OWT towers and foundations are analyzed, exploring various methods including model-based, vibration-based, artificial intelligence and hybrid fault diagnosis methods. The article also examines the advantages and disadvantages of each approach and outlines potential future directions for research and development in this field. Furthermore, it delves into the current damage identification techniques for OWT towers and foundations, discussing prevalent challenges and future directions in this domain. This status review can provide reference and guidance for the monitoring design of OWT support structures, and provide support for the fault diagnosis of OWT support structures.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-22
      DOI: 10.3390/jmse12030377
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 378: Enhanced Model Predictive Control for Induction
           Motor Drives in Marine Electric Power Propulsion System

    • Authors: Tongzhen Liu, Xuliang Yao, Jiabao Kou
      First page: 378
      Abstract: Marine electric propulsion is an important topic in the research of modern ships and underwater vehicles. The propulsion motor drives based on model predictive control (MPC) are becoming increasingly popular in marine propulsion systems as an emerging technology. However, the multi-objective optimization in conventional MPC requires cumbersome weighting factor tuning. The relatively large computational cost is also detrimental to the industrial application of MPC. Aiming at reducing the computational complexity of multi-objective optimization without weighting factors, this paper proposes an enhanced ranking-based MPC method for induction motor drives in marine electric power propulsion. The presented control set pre-optimization aims to reduce the computational complexity of enumeration and ranking. Based on the sign of torque prediction deviation, the proposed method avoids enumerating all fundamental voltage vectors. Consequently, the number of candidate elements in the initial control set are reduced to four without excessively excluding feasible solutions. By converting predicted numerical errors into ranking results, the proposed MPC seeks the optimal solution among the candidates through improved ranking evaluation. Considering the situation of simultaneous optimal ranking, the normalization error judgment is developed to further optimize the optimal solution selection process. The simulation and experimental results confirm that the proposed MPC is simple and effective. Without the involvement of tuning the weighting factors, the proposed method achieves good performance.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-22
      DOI: 10.3390/jmse12030378
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 379: Detection Technique Tailored for Small Targets
           on Water Surfaces in Unmanned Vessel Scenarios

    • Authors: Jian Zhang, Wenbin Huang, Jiayuan Zhuang, Renran Zhang, Xiang Du
      First page: 379
      Abstract: Lightweight detection methods are frequently utilized for unmanned system sensing; however, to tackle the challenge of low precision in detecting small targets on the water’s surface by unmanned surface vessels, we present an enhanced method for ship target detection tailored specifically to this context. Building upon the mainstream single-stage Yolov8 object detection model, our approach involves the integration of the Reparameterized Convolutional Spatial Oversampling Attention (RCSOSA) module, replacing the traditional Classic 2D Convolutional (C2f) module to bolster the network’s feature extraction capabilities. Additionally, we introduce a downsampling module, Spatial to Depth Convolution (SPDConv), to amplify the extraction of features relevant to small targets, thereby enhancing detection accuracy. Finally, the Focal Modulation module, based on focal modulation, replaces the SPPF (Spatial Pyramid Pooling with FPN) module, leading to a reduction in channel count, parameter volume, and an augmentation of the network’s feature representation. Experimental results demonstrate that the proposed model achieves a 3.6% increase in mAP@0.5 and a 2.1% improvement in mAP@0.5:0.95 compared to the original Yolov8 model, while maintaining real-time processing capabilities. The research validates the higher accuracy and stronger generalization capabilities of the proposed improved ship target detection method in various complex water surface environments.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-23
      DOI: 10.3390/jmse12030379
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 380: Operational Oceanography in Ports and Coastal
           Areas, Applications for the Management of Pollution Events

    • Authors: Andrea Cucco, Simone Simeone, Giovanni Quattrocchi, Roberto Sorgente, Andrea Pes, Andrea Satta, Matteo Sinerchia, Angelo Perilli, Alberto Ribotti
      First page: 380
      Abstract: Maritime safety and the protection of the marine environment were the primary objectives of two European projects that the National Research Council of Italy had participated in, with numerical applications in two areas located in the northern part of Sardinia, Italy. Specifically, two operational Numerical Prediction Systems (NPS) for pollution risk management were developed; the first was applied to the area of the Bonifacio Strait and the Gulf of Asinara and the second to the port of Olbia. These systems are composed of many oceans and particle tracking numerical models. They are forced with meteorological and ocean data provided by the European Centre for Medium-Range Weather Forecasts and Copernicus Marine Service and their outputs have been compared with in situ measurements for preliminary calibration. A web graphical interface was ad hoc designed, specifically responding to projects’ needs, providing online access to a 3-day oceanographic forecast and advanced diagnostic variables like Oil Stranding Time, Risk Score and Water Age. These products, along with the interactive web platform, prove invaluable for marine spatial planning, prevention and emergency management at sea, for the use of competent governmental and local bodies.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-23
      DOI: 10.3390/jmse12030380
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 381: Hydrodynamic Modeling of a Large, Shallow
           Estuary

    • Authors: Zhen-Gang Ji, M. Zaki Moustafa, John Hamrick
      First page: 381
      Abstract: Florida Bay, a large and shallow estuary, serves as a vital habitat for a diverse range of marine species and holds significant environmental, commercial, and recreational value. The Florida Bay ecosystem is under extensive stress due to decades of increased nutrient loads. Based on the Environmental Fluid Dynamics Code (EFDC), a hydrodynamic model was developed in this study. The model was calibrated with a comprehensive dataset, including measurements over 7 years from 34 tidal stations, 42 current stations, and 14 temperature and salinity stations. Key findings include the following: (1) the bay exhibits a shift in the tidal regime, transitioning from macro-tidal in the western region to micro-tidal in the central and eastern/northeast regions; (2) local winds and the subtidal variations from the coastal ocean are the primary drivers for the hydrodynamic processes in the eastern and central regions; (3) salinity changes in the bay are primarily controlled by three processes: the net supply of freshwater, the processes that drive mixing within the estuary (e.g., wind, topography, currents), and the exchange of salinity with the coastal ocean. This hydrodynamic model is essential for providing a comprehensive tool to address environmental challenges and sustain the bay’s ecosystem health.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-23
      DOI: 10.3390/jmse12030381
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 382: Route Planning Algorithms for Unmanned Surface
           Vehicles (USVs): A Comprehensive Analysis

    • Authors: Shimhanda Daniel Hashali, Shaolong Yang, Xianbo Xiang
      First page: 382
      Abstract: This review paper provides a structured analysis of obstacle avoidance and route planning algorithms for unmanned surface vehicles (USVs) spanning both numerical simulations and real-world applications. Our investigation encompasses the development of USV route planning from the year 2000 to date, classifying it into two main categories: global and local route planning. We emphasize the necessity for future research to embrace a dual approach incorporating both simulation-based assessments and real-world field tests to comprehensively evaluate algorithmic performance across diverse scenarios. Such evaluation systems offer valuable insights into the reliability, endurance, and adaptability of these methodologies, ultimately guiding the development of algorithms tailored to specific applications and evolving demands. Furthermore, we identify the challenges to determining optimal collision avoidance methods and recognize the effectiveness of hybrid techniques in various contexts. Remarkably, artificial potential field, reinforcement learning, and fuzzy logic algorithms emerge as standout contenders for real-world applications as consistently evaluated in simulated environments. The innovation of this paper lies in its comprehensive analysis and critical evaluation of USV route planning algorithms validated in real-world scenarios. By examining algorithms across different time periods, the paper provides valuable insights into the evolution, trends, strengths, and weaknesses of USV route planning technologies. Readers will benefit from a deep understanding of the advancements made in USV route planning. This analysis serves as a road map for researchers and practitioners by furnishing insights to advance USV route planning and collision avoidance techniques.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-23
      DOI: 10.3390/jmse12030382
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 383: Suppression of Negative Sequence Current on HVDC
           Modular Multilevel Converters in Offshore Wind Power

    • Authors: Xiaoning Xu, Di Wang, Xuesong Zhou, Long Tao
      First page: 383
      Abstract: The High Voltage Direct Current (HVDC) transmission technology employing modular multilevel converters (MMCs) can effectively enhance the transmission efficiency and stability of offshore wind farms, thereby aiding the promotion of large−scale utilization of new energy. This holds significant importance for achieving the dual carbon goals. Aiming at the problem of negative sequence current circulation in MMC−HVDC transmission systems, a circulation suppression strategy based on augmented order decoupling linear active disturbance rejection control (LADRC) is proposed in this paper. By introducing new state variables into the traditional ADRC structure, the actual output deviation signal and observation gain signal from the disturbance observation value of the system are used. It can not only realize the decoupling control of disturbance and tracking terms but also enhance the disturbance immunity, robustness and rapidity of the controller. Finally, an 18−level MMC system model is built based on Matlab (9.12.0.1884302 (R2022a)) & Simulink (R2022a), and the circulation suppression effects of stable operation and voltage sudden change are simulated and compared, which verifies the suppression effect of the improved control strategy on negative sequence current circulation, which lays a theoretical and application foundation for the sustainable development of the offshore wind power industry.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-23
      DOI: 10.3390/jmse12030383
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 384: Factors Influencing the Spatio-Temporal
           Distribution of Chlorophyll-a in Jinmeng Bay, China

    • Authors: Wang, Kuang, Wang, Liu, Song, Xing, Zou
      First page: 384
      Abstract: Field observations were combined with a coupled hydrodynamic and water quality model to investigate the spatial and temporal variation in Chlorophyll-a (Chl-a) in Jinmeng Bay, China. The relatively high Chl-a values were distributed in the inshore waters, mainly due to the abundant nutrient inflow from the Tanghe River. The model’s results indicate that the Chl-a concentration was much higher in seaweed beds surrounded by artificial islands and reefs under the southeasterly wind, largely due to the fact that pollutants are prone to accumulate in coastal areas where flow is attenuated by the presence of natural and artificial marine structures. It was also found that the southwesterly winds suppress the inflow of nutrients from the Tanghe River to the coastal areas, and, therefore, lower the Chl-a levels. River input and wind forcing are the major factors that influence Chl-a concentrations in the anthropogenically influenced bay. This finding provides useful guidance for the prediction and mitigation of green tides in Jinmeng Bay in the future.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-23
      DOI: 10.3390/jmse12030384
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 385: Failure Behavior of Corrugated Pressure
           Cylindrical Shells with Variable Wall Thickness under Uniform External
           Pressure

    • Authors: Jianliang Sun, Xu Zhang, Yuanhe Zhang, Xianghui Lu, Yan Peng
      First page: 385
      Abstract: The main load-bearing structure of submarines is the pressure shell. Shell failures are usually caused by high hydrostatic pressure and its own potential geometric imperfections. This paper proposes a cylindrical shell with a strong corrugated stiffening structure. Two theoretically geometrically identical shells are fabricated using CNC machining to ensure the reproducibility and reasonableness of the results. Firstly, the point cloud data of all the geometric parameters of the corrugated pressure cylindrical shells were obtained using a 3D scanner. Geomagic Control X 3D inspection software was used to determine the geometric deviations of the shells. Geometric reconstruction was performed using Geomagic Design X reverse modeling software to capture potential imperfections of the shells. The aluminum shells were then welded and placed in the pressure chamber. Failure loads were obtained for all shells by constant water injection and pressurization. Considering the confined nature of the pressure chamber, a nonlinear finite element analysis of the corrugated pressure cylindrical shell was carried out using Abaqus/Riks, taking into account actual fabrication imperfections. Finally, the failure behavior of the shells under uniform external pressure was determined. The results show that both corrugated pressure cylindrical shells have high machining accuracy. The numerical simulation results of the critical buckling load of the corrugated pressure cylindrical shells were in good agreement with the test results. The corrugated structure has additional advantages in retarding the generation and expansion of shell surface defects. The equilibrium path of the corrugated pressure cylindrical shell can be maintained in a smooth and continuous state, showing stable buckling behavior. This study will provide new inspiration for the structural design and failure prediction of the submarine pressure shell.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-23
      DOI: 10.3390/jmse12030385
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 386: Coastal Management: A Review of Key Elements for
           Vulnerability Assessment

    • Authors: Cesia J. Cruz-Ramírez, Valeria Chávez, Rodolfo Silva, Juan J. Muñoz-Perez, Evelia Rivera-Arriaga
      First page: 386
      Abstract: Damaging and accelerated anthropization in coastal areas, as well as the need to adapt to climate change, means we must concentrate on improving management plans based on the diagnoses provided by coastal studies. Among these studies is the vulnerability assessment, obtained from evaluating a set of variables or indicators, which contribute to sustainable development. Since there is no single list of variables to consider in determining coastal vulnerability, 60 vulnerability studies from a period of 29 years (1994–2023), from across the globe, were consulted, and through a statistical mode method, the variables most used by multidisciplinary authors were identified. These studies were organized into groups: ecological, geomorphological, maritime climate, socioeconomic and legislative; creating sets categorized as the minimum indispensable, acceptable, and ideal variables. The results showed that most studies use between six and seven variables from only the maritime climate and geomorphological information groups. The number of variables used by individual studies, on the other hand, was not directly related to the scales (global, national, regional, local), but to the risks, such as flooding and erosion, it resolved. Only two studies included the minimum essential information for the legislative group, which is the presence of protected natural areas. Coastline displacements was the variable most used (43 studies), followed by the geoform type and the rate of sea level change (36), the wave regime (35) and the tidal range (33). The DSSs (Decision Support Systems) for coastal management were also reviewed, showing that these systems focus on a topic with a greater number of variables.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-23
      DOI: 10.3390/jmse12030386
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 387: Ship SINS/CNS Integrated Navigation Aided by
           LSTM Attitude Forecast

    • Authors: Jun Tang, Hongwei Bian
      First page: 387
      Abstract: Under the strong interference of sky background noise, the reliability of celestial navigation system (CNS) measurement will drop sharply, which leads to performance deterioration for ships’ strapdown inertial navigation system (SINS)/CNS integrated navigation. To solve this problem, a long short-term memory (LSTM) model is trained to forecast a ship’s attitude to detect the attitude provided by the CNS, and the LSTM forecasted attitude can also be used as a backup in case of CNS failure. First, the SINS/CNS integrated model is derived based on an attitude solution of the CNS, which provides more favorable feature data for LSTM learning. Then, the key techniques of LSTM modeling such as dataset construction, LSTM coding method, hyperparameter optimization and training strategy are described in detail. Finally, an experiment is conducted to evaluate the actual performance of the investigated methods. The results show that the LSTM model can accurately forecast a ship’s attitude: the horizon reference error is less than 0.5′ and the yaw error is less than 0.6′, which can provide reliable reference attitude for the SINS when the CNS is invalid.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-23
      DOI: 10.3390/jmse12030387
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 388: Impact of Operational Configuration Onboard a
           Drillship on Main Generator Engine Subcomponents Interval and Maintenance
           Strategies

    • Authors: Josip Dujmović, Darko Glujić, Predrag Kralj, Vladimir Pelić
      First page: 388
      Abstract: Maintenance intervals and approaches for marine equipment have been the subject of numerous studies, focusing on previous failure patterns and associated risks. However, in vessels like drillships, operating under high reliability requirements and possessing significant redundancy, maintenance strategies have a critical impact on overall performance. This study investigates the influence of operational configurations on maintenance intervals and approaches for generator engine subcomponents onboard a drillship. Using data on injector failures onboard drillships, we employ the maintenance concept adjustment and design (MA-CAD) method to analyse and determine maintenance intervals across various operational configurations. Initially, we analyse the failure pattern of fuel injectors and propose a reduction in maintenance intervals through Weibull probability distribution fitting. Additionally, a risk analysis is conducted to assess the impact of operational configurations on risk indices related to fuel injector reliability and safety consequences. Our findings reveal that different operational configurations of the power generation plant can lead to changes in risk indices, shifting injector reliability status from unacceptable to undesirable limits. Consequently, maintenance intervals need to be adjusted as well to ensure optimal performance and safety. Furthermore, considering various engine subcomponents and their reliability under different operational configurations suggests the need for tailored maintenance approaches. This research provides insights into optimising maintenance strategies for drillship, ensuring reliability and safety across diverse operational scenarios.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-23
      DOI: 10.3390/jmse12030388
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 389: The Photoperiod Significantly Influences the
           Growth Rate, Digestive Efficiency, Immune Response, and Antioxidant
           Activities in the Juvenile Scalloped Spiny Lobster (Panulirus homarus)

    • Authors: Yinggang Wang, Rui Yang, Zhengyi Fu, Zhenhua Ma, Zemin Bai
      First page: 389
      Abstract: This study aimed to elucidate the effects of different photoperiods (0 L:24 D, 6 L:18 D, 12 L:12 D, 18 L:6 D, 24 L:0 D, “Light (L) and Dark (D)”) on the growth performance and physiological responses of the juvenile scalloped spiny lobster (Panulirus homarus). Over a period of 56 days, parameters such as growth rate, digestive enzyme, immune enzyme, and antioxidant enzyme were meticulously evaluated in 90 lobsters subjected to these varying light conditions. The present study found no significant differences in survival rate (SR), molting frequency (MF), and meat yield production (MYP) among the various photoperiod treatments (p > 0.05). Notably, the highest weight gain rate (WGR) and specific growth rate (SGR) were observed under a 12 L:12 D photoperiod. In the continuous dark phase (0 L:24 D), pepsin (PEP) activity remained high in gastric tissues, while trypsin (TRYP) and chymotrypsin (CHT) activities reached the highest in hepatopancreas tissues. The α-amylase (AMS) activity in the hepatopancreas was most elevated under 18 L:6 D, and the optimal lipase (LPS) activity was recorded under 12 L:12 D. The activity of acid phosphatase (ACP) in the hepatopancreas was highest in the absence of light (0 L:24 D), whereas the activities of alkaline phosphatase (AKP) and lysozyme (LZM) were most effective under the 12 L:12 D photoperiod. The total antioxidant capacity (T-AOC), along with catalase (CAT) and superoxide dismutase (SOD) activities of the hepatopancreas reached the highest at 12 L:12 D. The highest activity of glutathione peroxidase (GSH-Px) was seen under 18 L:6 D. The concentration of malondialdehyde (MDA), a marker of oxidative stress, was found to be highest under 12 L:12 D. Consequently, this specific photoperiod is essential for achieving optimal growth and maintaining appropriate physiological balance in the scalloped spiny lobster during aquaculture. These findings provide a foundational guideline for establishing the lighting environment in the farming of the juvenile scalloped spiny lobster.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-24
      DOI: 10.3390/jmse12030389
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 390: Probabilistic Analysis of Basic Causes of
           Vessel–Platform Allision Accidents

    • Authors: Bhardwaj, Teixeira, Guedes Soares
      First page: 390
      Abstract: This paper proposes a methodology to estimate the probability of basic causes of allision accidents between vessels and offshore platforms that overcomes the problem of data scarcity required for causal analysis. The approach uses information derived from incidental data and expert elicitation, processed by a multiple attribute utility method and hierarchical Bayesian analysis. First, the methodology is detailed, briefly describing the adopted approaches. A dataset of allision incidents provided mainly by the UK Health and Safety Executive and other agencies is prepared. The features of the incidents’ causation in terms of the causal factors and basic causes are presented and discussed. A novel scheme is proposed to evaluate the annual occurrence rates of basic causes of accidents from the relative importance of each basic cause derived by the Deck of Cards method. Then, a hierarchical Bayesian analysis is conducted to predict the posterior distribution of the occurrence rate of each basic cause in the time frame under analysis. The proposed holistic methodology provides transparent estimates of allision causation probabilities from limited and heterogeneous datasets.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-24
      DOI: 10.3390/jmse12030390
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 391: Transient Tests for Checking the Trieste Subsea
           Pipeline 2: Diving into Fault Detection

    • Authors: Silvia Meniconi, Bruno Brunone, Lorenzo Tirello, Andrea Rubin, Marco Cifrodelli, Caterina Capponi
      First page: 391
      Abstract: Fault detection in subsea pipelines is a difficult problem for several reasons, and one of the most important is the inaccessibility of the system. This criticality can be overcome by using transient test-based techniques. Such an approach is based on the execution of safe transients that result in small over pressures (i.e., on the order of a few meters of water column). In our companion paper, the procedure involving the transient tests was described in detail. This paper analyses the results of the field tests carried out and identifies wall deterioration in some sections of the pipeline. Attention is focused on the numerical procedure based on the joint use of a 1-D numerical model simulating transients in the pressurized flow and analytical relationships and providing the transient response of anomalies such as leaks and wall deterioration. The results obtained are essentially confirmed by the survey carried out by divers.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-24
      DOI: 10.3390/jmse12030391
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 392: A Review of Numerical and Physical Methods for
           Analyzing the Coupled Hydro–Aero–Structural Dynamics of
           Floating Wind Turbine Systems

    • Authors: Mojtaba Maali Amiri, Milad Shadman, Segen F. Estefen
      First page: 392
      Abstract: Recently, more wind turbine systems have been installed in deep waters far from the coast. Several concepts of floating wind turbine systems (FWTS) have been developed, among which, the semi-submersible platform—due to its applicability in different water depths, good hydrodynamic performance, and facility in the installation process—constitutes the most explored technology compared to the others. However, a significant obstacle to the industrialization of this technology is the design of a cost-effective FWTS, which can be achieved by optimizing the geometry, size, and weight of the floating platform, together with the mooring system. This is only possible by selecting a method capable of accurately analyzing the FWTS-coupled hydro–aero–structural dynamics at each design stage. Accordingly, this paper provides a detailed overview of the most commonly coupled numerical and physical methods—including their basic assumptions, formulations, limitations, and costs used for analyzing the dynamics of FWTS, mainly those supported by a semi-submersible—to assist in the choice of the most suitable method at each design phase of the FWTS. Finally, this article discusses possible future research directions to address the challenges in modeling FWTS dynamics that persist to date.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-24
      DOI: 10.3390/jmse12030392
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 393: Physical and Mechanical Properties of
           All-Solid-Waste-Based Binder-Modified Abandoned Marine Soft Soil

    • Authors: Qiang Liu, Junjie Yang, Yalei Wu, Zimou Wang, Xinyi Qiu, Lijun Yan
      First page: 393
      Abstract: Large quantities of abandoned marine soft soil are generated from coastal engineering which cannot be directly utilized for construction without modification. The utilization of traditional binders to modify abandoned marine soft soil yields materials with favorable mechanical properties and cost efficiency. However, the production of traditional binders like cement leads to environmental pollution. This study uses a CGF all-solid-waste binder (abbreviated as CGF) composed of industrial solid waste materials such as calcium carbide residue (CCR), ground granulated blast furnace slag (GGBS), and fly ash (FA), developed by our research team, for the modification of abandoned marine soft soil (referred to as modified soil). It is noteworthy that the marine soft soil utilized in this study was obtained from the coastal area of Jiaozhou Bay, Qingdao, China. Physical property tests, compaction tests, and unconfined compressive strength (UCS) tests were conducted on the modified soil. The investigation analyzed the effects of binder content, compaction delay time, and curing time on the physical, compaction, and mechanical properties of CGF-modified soil and cement-modified soil. Additionally, microscopic experimental results were integrated to elucidate the mechanical improvement mechanisms of CGF on abandoned marine soft soil. The results show that after modification with binders, the water content of abandoned marine soft soil significantly decreases due to both physical mixing and chemical reactions. With an increase in compaction delay time, the impact of chemical reactions on reducing water content gradually surpasses that of physical mixing, and the plasticity of the modified soil notably modifies. The addition of binders results in an increase in the optimum moisture content and a decrease in the maximum dry density of CGF-modified soil, while the optimum moisture content decreases and the maximum dry density increases for cement-modified soil. Moreover, with an increase in binder content, the compaction curve of CGF-modified soil gradually shifts downward and to the right, while for cement-modified soil, it shifts upward and to the left. Additionally, the maximum dry density of both CGF-modified and cement-modified soils shows a declining trend with the increase in compaction delay time, while the optimum moisture content of CGF-modified soil increases and that of cement-modified soil exhibits a slight decrease. The strength of compacted modified soil is determined by the initial moisture ratio, binder content, compaction delay time, and curing time. The process of CGF modification of marine soft soil in Jiaozhou Bay can be delineated into stages of modified soil formation, formation of compacted modified soil, and curing of compacted modified soil. The modification mechanisms primarily involve the alkali excitation reaction of CGF itself, pozzolanic reaction, ion-exchange reaction, and carbonization reaction. Through quantitative calculations, the carbon footprint and unit strength cost of CGF are both significantly lower than those of cement.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-24
      DOI: 10.3390/jmse12030393
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 394: Application of Shore Sediments Accumulated in
           Navigation Channel for Restoration of Sandy Beaches around Pärnu
           City, SW Estonia, Baltic Sea

    • Authors: Hannes Tõnisson, Rain Männikus, Are Kont, Valdeko Palginõmm, Victor Alari, Sten Suuroja, Tiit Vaasma, Kadri Vilumaa
      First page: 394
      Abstract: Sandy beaches high in recreation value make up 16% of the over 4000 km long shoreline of Estonia. The shore processes associated with climate change have remarkably accelerated over recent decades. Many sandy shores have suffered from strong erosion, including an excellent former beach at Valgeranna. The jetties, which were built in the 1860s to protect the navigation channel of Port Pärnu from clogging, have prevented natural sediment transport along the coast from south to north. At the same time, the sandy beach in Pärnu is expanding, and part of the sand accumulates with strong storms also in between the jetties, reducing the width of the shipping channel. The channel needs regular dredging, but, so far, the dredged sediment has been taken far away to the open sea and accumulated on the seabed. The current paper addresses the possibilities of using that sand for beach restoration in destructed and eroded areas. An overview of the applied methods and measurements during field studies is given. The results of modelling the processes of wave activity and sediment transport are discussed. The recycling of shore sediments is an important measure in sustainable coastal zone management. Different options and scenarios are analysed in order to find the most reasonable ways to bring sand back onto beaches and stabilize natural processes. Support from the state by working out respective laws and regulations would be motivating as well.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-24
      DOI: 10.3390/jmse12030394
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 395: Investigating Load Calculation for Broken Ice
           and Cylindrical Structures Using the Discrete Element Method

    • Authors: Chuan Wang, Jinjing Gong, Ya Zhang, Lianghai Liu, Min Lou
      First page: 395
      Abstract: Ice loads are critical forces that impact the structural integrity of offshore equipment in high-latitude sea areas and play a pivotal role in the design of structures in ice-prone regions. The primary objective of this study is to investigate both experimental and numerical approaches to analyze ice loads on marine structures, elucidate their characteristics and patterns, and offer technical support for the design of structures in ice-prone areas. To achieve this goal, an ice model was built using polypropylene material, and experiments were conducted in a wave flume at room temperature to measure the ice resistance on cylindrical structures. Structural loads were assessed at various ice velocities while maintaining a fixed ice concentration. Furthermore, a high-performance discrete element technology was employed to develop a numerical simulation method for calculating ice resistance on cylindrical structures. Sensitivity analysis was conducted to evaluate the influence of discrete element density on the resistance outcomes. The predicted structural resistance for ice velocities corresponding to the experimental conditions was compared with the results obtained from the model experiment. The research findings indicate that the primary cause of ice resistance is the interaction between the structure and fragmented ice, which leads to collisions, friction, rotation, and local ice accumulation. To quantify the resistance, ice resistance coefficients were defined using an average resistance formula, representing different statistical values. These coefficients were found to remain relatively constant at varying sailing speeds. The results obtained through the discrete element method for ice resistance demonstrated a remarkable agreement with the experimental findings, both in terms of observed phenomena and numerical values. This agreement serves as evidence substantiating the effectiveness of the numerical approach. These methods offer efficient and accurate load prediction solutions for the design of structures in cold regions.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-25
      DOI: 10.3390/jmse12030395
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 396: Multi-Parameter Fuzzy-Based Neural Network
           Sensorless PMSM Iterative Learning Control Algorithm for Vibration
           Suppression of Ship Rim-Driven Thruster

    • Authors: Zhi Yang, Xinping Yan, Wu Ouyang, Hongfen Bai, Jinhua Xiao
      First page: 396
      Abstract: Aiming to reduce motor speed estimation and torque vibration present in the permanent magnet synchronous motors (PMSMs) of rim-driven thrusters (RDTs), a position-sensorless control algorithm using an adaptive second-order sliding mode observer (SMO) based on the super-twisting algorithm (STA) is proposed. In which the sliding mode coefficients can be adaptively tuned. Similarly, an iterative learning control (ILC) algorithm is presented to enhance the robustness of the velocity adjustment loop. By continuously learning and adjusting the difference between the actual speed and given speed of RDT motor through ILC algorithm, online compensation for the q-axis given current of RDT motor is achieved, thereby suppressing periodic speed fluctuations during motor running. Fuzzy neural network (FNN) training can be used to optimize the STA-SMO and ILC parameters of RDT control system, while improving speed tracking accuracy. Finally, simulation and experimental verifications have been conducted on the vector control system based on the conventional PI-STA and modified ILC-STA. The results show that the modified algorithm can effectively suppress the estimated speed and torque ripple of RDT motor, which greatly improves the speed tracking accuracy.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-25
      DOI: 10.3390/jmse12030396
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 397: Air Pollution PM10 Forecasting Maps in the
           Maritime Area of the Bay of Algeciras (Spain)

    • Authors: María Inmaculada Rodríguez-García, María Gema Carrasco-García, Maria da Conceição Rodrigues Ribeiro, Javier González-Enrique, Juan Jesús Ruiz-Aguilar, Ignacio J. Turias
      First page: 397
      Abstract: Predicting the levels of a pollutant in a given area is an open problem, mainly because historical data are typically available at certain locations, where monitoring stations are located, but not at all locations in the area. This work presents an approach based on developing predictions at each of the points where an immission station is available; in this case, based on shallow Artificial Neural Networks, ANNs, and then using a simple geostatistical interpolation algorithm (Inverse Distance Weighted, IDW), a pollutant map is constructed over the entire study area, thus providing predictions at each point in the plane. The ANN models are designed to make 1 h ahead and 4 h ahead predictions, using an autoregressive scheme as inputs (in the case of 4 h ahead as a jumping strategy). The results are then compared using the Friedman and Bonferroni tests to select the best model at each location, and predictions are made with all the best models. In general, to the 1 h ahead prediction models, the optimal models typically have fewer neurons and require minimal historical data. For instance, the best model in Algeciras has an R of almost 0.89 and consists of 1 hidden neuron and 3 to 5 lags, similar to Colegio Los Barrios. In the case of 4h ahead prediction, Colegio Carteya station shows the best model, with an R of almost 0.89 and a MSE of less than 240, including 5 hidden neurons and different lags from the past. The results are sufficiently adequate, especially in the case of predictions 4 h into the future. The aim is to integrate the models into a tool for citizens and administrations to make decisions.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-25
      DOI: 10.3390/jmse12030397
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 398: Field Determination and Spatial Distribution of
           Se (IV) in Coastal Seawater of China

    • Authors: Tianzhuo Liu, Dawei Pan, Hong Wei, Yan Liang, Ying Li, Md. Abdur Rahman
      First page: 398
      Abstract: A portable electrochemical system based on rGO/AuNPs/Nafion was constructed for selenium (IV) field determination in coastal seawater of the North Yellow Sea, East China Sea and South China Sea. This system demonstrated a low determination limit (0.03 μg/L), a wide linear range of concentration (0.1–30 μg/L), exceptional reproducibility and repeatability, and excellent selectivity. Each individual, entire test could be accomplished within 8 min. In Yantai Sishili Bay, the Se (IV) concentrations ranged from 0.16–3.59 μg/L (average 1.43 μg/L). In Shengshan Island, the Se (IV) concentrations ranged from 0.20–5.18 μg/L (average 2.06 μg/L). In Zhelin Bay, the Se (IV) concentrations ranged from 0.87–4.87 μg/L (average 3.13 μg/L). The average concentrations of Se (IV) in surface seawater showcased an increasing trend from the north to the south of China, suggesting Zhelin Bay > Shengshan Island > Sishili Bay. The system develops a new, competitive method for water quality assessment, and contributes to the accurate study of the biogeochemical cycles of selenium.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030398
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 399: Added Value of Water Column Spatiotemporal
           Monitoring to Assess Variability of Trace Metal Elements and Organotin
           Compounds in Mediterranean Harbours

    • Authors: Cyrine Chouba, Olivier Pringault, Aurélien Domeau, Sophie Delpoux, Léa Causse, Mylène Marie, Rémi Freydier, Chrystelle Montigny
      First page: 399
      Abstract: Marinas are semi-enclosed environments characterised by reduced hydrodynamic energy, high sedimentation rates, and reduced oxygen levels. The ongoing development of activities and infrastructure construction are leading to deterioration in the quality of coastal aquatic environments, creating environmental risks. Trace metal elements (TMEs) and organotins are significant contaminants, prompting this study to evaluate the added value of spatiotemporal monitoring compared to one-time sediment assessments. Two Mediterranean harbours, Port Camargue (PC) and Port Carnon (C), differing in morphology and size, were monitored for a year with regular water sampling, focusing on TMEs and organotins. Sediment contamination, notably in the technical zone, revealed concentrations of Cu (309 and 1210 mg kg−1 for C and PC, respectively), Zn (242 and 425 mg kg−1 for C and PC, respectively), and tributyltin (TBT) (198 and 4678 µg (Sn) kg−1 for C and PC, respectively) surpassing the effect range medium (ERM), while other marina stations generally stayed below this threshold. Spatiotemporal water monitoring highlighted concentrations above environmental quality standards (EQS) at all stations of the larger marina. This exceedance was systematic for Cu and Zn in all samples, ranging respectively between 2.54 and 37.56 µg (Sn) L−1 and 0.63 and 33.48 µg (Sn) L−1. A notable temporal dynamic for TBT and Cu was also observed. Conversely, the open marina, connected to the open sea, rarely exhibited concentrations above EQS in water, despite sediment concentrations occasionally exceeding ERM values. This underscores that risk assessment in these ecosystems cannot rely solely on sediment characterisation.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030399
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 400: Expendable
           Conductivity–Temperature–Depth-Assisted Fast Underwater Sound
           Speed Estimation by Convolutional Neural Network with Reduced Fully
           Connected Layers

    • Authors: Sijia Li, Hao Zhang, Jiajun Lu, Pengfei Wu, Wei Huang
      First page: 400
      Abstract: Obtaining accurate sound speed profiles (SSPs) in near-real-time is of great significance for ocean exploration, underwater communication and improving the performance of sonar systems. In response to the problem that traditional sound speed estimation methods cannot obtain real-time sound speed distribution or rely too much on sonar observation data, we propose an SSP estimation method based on a convolutional neural network with reduced fully connected layers (RFC-CNN) in this paper. This method utilizes neural networks to extract the complex nonlinear features of various types of data. With the help of the historical SSPs and shallow seawater sound speed and temperature data obtained by expendable conductivity–temperature–depth probes (XCTDs), a more accurate estimation of the regional sound speed distribution can be realized quickly. This approach can save the observation cost and significantly improve the real-time performance of SSP estimation.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030400
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 401: Assessing the Effectiveness of Regional Storm
           Surge Reduction Strategies and Tank Level Structural Mitigation Measures
           for Aboveground Storage Tanks

    • Authors: Santosh Ghimire, Sabarethinam Kameshwar
      First page: 401
      Abstract: The effectiveness of regional storm surge reduction strategies and tank-level structural mitigation measures in reducing the failure probability of aboveground storage tanks (ASTs) were studied. Given past failures during flood and hurricane events, several studies have developed fragility models for ASTs. However, the suitability of these fragility models for different hurricane hazard scenarios is unknown. Furthermore, to combat climate change and sea level rise, several regional storm surge reduction strategies are being proposed. However, the effectiveness of these strategies in improving the safety of ASTs is also unknown. So, herein, a framework was proposed that facilitates assessing the suitability of fragility models and the quantification of AST failures and their consequences while propagating uncertainties using Monte Carlo simulations. The application of the proposed framework to Cameron, Louisiana, provided several key insights: (1) fragility models that do not model wave loads and dislocation failure are not suitable for the region; (2) a regional risk mitigation strategy was insufficient for lowering future spill volume, repair, and cleanup costs; and (3) considering bottom-plate failure of anchored tanks—a structural risk mitigation measure—would lead to a 47–72% reduction in the consequences of tank failure.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030401
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 402: An Improved VO Method for Collision Avoidance of
           Ships in Open Sea

    • Authors: Mao Zheng, Kehao Zhang, Bing Han, Bowen Lin, Haiming Zhou, Shigan Ding, Tianyue Zou, Yougui Yang
      First page: 402
      Abstract: In order to effectively deal with collisions in various encounter situations in open water environments, a ship collision avoidance model was established, and multiple constraints were introduced into the velocity obstacle method, a method to determine the ship domain by calculating the safe distance of approach was proposed. At the same time, the ship collision avoidance model based on the ship domain is analyzed, and the relative velocity set of the collision cone is obtained by solving the common tangent line within the ellipse. The timing of starting collision avoidance is determined by calculating the ship collision risk, and a method for ending collision avoidance is proposed. Finally, by comparing the simulation experiments of the improved algorithm with those of the traditional algorithm and the actual ship experiment results of manual ship maneuvering, it is shown that the method can effectively avoid collisions based on safe encounter distances that comply with navigation experience in different encounter situations. At the same time, it has better performance in collision avoidance behavior. It has certain feasibility and practical applicability.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030402
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 403: Overview of Predation by Birds, Cephalopods,
           Fish and Marine Mammals on Marine Benthic Amphipods

    • Authors: Jean-Claude Dauvin
      First page: 403
      Abstract: With about 8000 marine benthic species, the amphipod crustaceans form one of the richest animal groups of the worldwide Ocean. They have colonized a wide range of soft- and hard-bottom natural and artificial habitats extending from the intertidal to hadal zones. Moreover, they show a broad size spectrum, with numerous giant species exceeding 20 cm in length and some species smaller than 2 mm. When biofouling artificial hard surfaces, some tube-building species can form very dense populations comprising up to 100,000 individuals per square meter. Amphipods are important prey for fish and mammals. Along with cephalopod juveniles, they are also included in the trophic diet of shorebirds that consume amphipods mostly during the low tide on tidal flats. They display diel migration, which reinforces the predation by demersal fish in the suprabenthic zone just above the sea bed, as well as by pelagic fish in the water column. Despite their importance in terms of biodiversity and trophic transfer, no general overview is available on the role of benthic amphipods in marine ecosystem food webs. Various methods, including laboratory and field experiments, as well as the analysis of stomach contents and DNA extraction, have been used to identify the prey/predator trophic links. Based on an extensive literature review, this study discusses the role of marine benthic amphipods as potential food for higher trophic levels in natural and artificial hard-bottom communities created via the construction of offshore wind farms.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030403
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 404: Dual-Loop Integral Sliding Mode Control-Based
           Path Tracking with Reaction Torque for Autonomous Underwater Vehicle

    • Authors: Yakang Ju, Wenyu Cai, Ziqiang Liu, Meiyan Zhang
      First page: 404
      Abstract: Path tracking control is an important method for a Six-Degree-Of-Freedom Autonomous Underwater Vehicle to perform specific underwater tasks. Therefore, this paper investigates a dual-loop integral sliding mode control (DLISMC)-based tracking controller for an AUV with model uncertainties and external disturbances, and introduces a new reaction torque model for static compensation in order to improve the attitude control capability for AUVs when performing path tracking. In addition, the stability of tracking control law based on DLISMC is demonstrated using the Lyapunov function. Finally, numerical simulations are carried out on MATLAB 2016/Simulink and compared with the Proportion–Integral–Differential (PID) control commonly used in industry as well as the dual-loop Proportion–Integral–Differential (DLPID). Simulation results show that the DLISMC has a smaller tracking error, faster convergence speed, and more robustness against external disturbances and reaction torque.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030404
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 405: A Simulation Model of the Influence of LNG Ships
           on Traffic Efficiency at Tianjin Port

    • Authors: Yanwei Li, Wuliu Tian, Beibei Meng, Jinfen Zhang, Ruisai Zhou
      First page: 405
      Abstract: Tianjin Port is one of the largest ports in northern China. Liquefied natural gas (LNG) ships are one of the most special ship types, and their navigation safety and efficiency has become the top concern of the port authority. There are two LNG berths at the port, and the annual arrivals, which reach more than 100, increasingly influence other ships. The objective of this study is to evaluate the influence of LNG ships on other ships in a quantitative way. To realize this, a simulation system is established by analyzing the factors affecting waterway transit efficiency. The software Arena is adopted to simulate the arrival and departure of the ships at Tianjin Port and to simulate how the average waiting time and the average queue length in the port area are affected by the LNG ships. A traffic system for the two ship types is formulated, and the mutual influences between them are expressed by the inbound and outbound waterway states. The simulations are performed under both existing and new ship traffic regulations. Cases in which the number of LNG ships gradually increases are simulated comprehensively. The simulation model as well as the results can serve as a good reference for the local port authority in the formulation of traffic regulations.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030405
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 406: Compressive Behavior of Stainless
           Steel–Concrete–Carbon Steel Double-Skin Tubular (SCCDST)
           Members Subjected to External Hydraulic Pressure

    • Authors: Jian-Tao Wang, Kai-Lin Yang, Jia-Yao Sun
      First page: 406
      Abstract: The new-type stainless steel–concrete–carbon steel double-skin tubular (SCCDST) members, characterized by their exceptional corrosion resistance and mechanical bearing capacity, have promising applications in ocean engineering, particularly in deep-water engineering. The external hydraulic pressure and interfacial action of various materials intensify the complexity of composite performance of SCCDST members. This paper describes an analytical investigation on the concentric compressive performance of SCCDST members under external hydraulic pressure. The full-range mechanism, including load–displacement response, bearing capacity contribution, and contact pressures, was investigated through the finite element (FE) model that was validated by the failure mode, bearing capacity, and response of axial load versus strain. Subsequently, influences of key geometric–physical parameters were analyzed, e.g., diameter-to-thickness ratios (Do/to, Di/ti), material strengths (fyo, fyi, and fc), hollow ratios (χ), and water depths (H). Typical results indicate that: the initial active confinement action derived from the hydraulic pressure can enhance the interfacial contact pressure and axial compression capacity of SCCDST members due to the tri-axial compression state; the enhancement of confinement effect is mainly from the interfacial interaction between outer stainless steel tube and concrete infill; influence of water depth on bearing capacity cannot be ignored, e.g., the bearing capacity of an SCCDST member with larger hollow ratio (χ = 0.849) is not enhanced under a higher hydraulic pressure (H = 900 m) because of the cross-sectional buckling failure risk. Finally, a modified method considering the effect of water depth was proposed and verified for SCCDST members under hydraulic pressure.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030406
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 407: Effect of Sampling Rate in Sea Trial Tests on
           the Estimation of Hydrodynamic Parameters for a Nonlinear Ship Manoeuvring
           Model

    • Authors: Haitong Xu, P. Pires da Silva, C. Guedes Soares
      First page: 407
      Abstract: This paper explores the impact of sampling rates during sea trials on the estimation of hydrodynamic parameters in a nonlinear manoeuvring model. Sea trials were carried out using an offshore patrol vessel and test data were collected. A nonlinear manoeuvring model is introduced to characterise the ship’s manoeuvring motion, and the truncated least squares support vector machine is employed to estimate nondimensional hydrodynamic coefficients and their corresponding uncertainties using the 25°–25° zigzag test. To assess the influence of the sampling rates, the training set is resampled offline with 14 sampling rates, ranging from 0.2 Hz to 5 Hz, encompassing a rate 10 times the highest frequency component of the signal of interest. The results show that the higher sampling rate can significantly diminish the parameter uncertainty. To obtain a robust estimation of linear and nonlinear hydrodynamic coefficients, the sampling rate should be higher than 10 times the highest frequency component of the signal of interest, and 3–5 Hz is recommended for the case in this paper. The validation is also carried out, which indicates that the proposed truncated least square support vector machine can provide a robust parameter estimation.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030407
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 408: Review of Asymmetric Seafloor Spreading and
           Oceanic Ridge Jumps in the South China Sea

    • Authors: Jiangong Wei, Shuangling Dai, Huai Cheng, Houjin Wang, Pengcheng Wang, Fuyuan Li, Zhiyuan Xie, Rongwei Zhu
      First page: 408
      Abstract: Seafloor spreading is an important cornerstone of the theory of plate tectonics. Asymmetric seafloor spreading and oceanic ridge jumps are common phenomena in this process and play important roles in controlling oceanic crust accretion, regional tectonics and geological geometric boundaries. As the largest marginal sea in the western Pacific, the South China Sea is an ideal laboratory for dissecting the Wilson cycle of small marginal sea-type ocean basins restricted by surrounding blocks and exploring the deep dynamic processes of confined small ocean basins. In recent years, a lot of research has been conducted on the spreading history of the South China Sea and has achieved fruitful results. However, the detailed dynamic mechanisms of asymmetric seafloor spreading and ridge jumps are still unclear. Therefore, this paper summarizes the basic understanding about the dynamic mechanisms of global asymmetric seafloor spreading and ridge jumps and reviews the related research results of asymmetric seafloor spreading and ridge jumps in the South China Sea. Previous studies have basically confirmed that seafloor spreading in the South China Sea started between ~32 and 34 Ma in the east sub-basin and ended at ~15 Ma in the northwest sub-basin, with at least once oceanic ridge jump in the east sub-basin. The current research mainly focuses on the age of the seafloor spreading in the South China Sea and the location, time and stage of the ridge jumps, but there are relatively few studies on high-resolution lithospheric structure across these ridges and the dynamic mechanism of oceanic ridge jumps. Based on the current research progress, we propose that further studies should focus on the lithosphere–asthenosphere scale in the future, suggesting that marine magnetotelluric and Ocean Bottom Seismometer (OBS) surveys should be conducted across the residual oceanic ridges to perform a detailed analysis of the tectonics magmatism in the east sub-basin to gain insights into the dynamic mechanisms of oceanic ridge jumps and asymmetric seafloor spreading, which can promote understanding of the tectonic evolution of the South China Sea and improve the classical plate tectonics theory that was constructed based on the open ocean basins.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030408
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 409: Load Assessment Method for Multi-Layer
           Oceanographic Winch with Synthetic Fibre Ropes Based on Non-Rotation
           Symmetric Cylindrical Model

    • Authors: Haoran Ye, Wenhua Li, Shanying Lin, Qingtao Lv, Dinghua Zhang
      First page: 409
      Abstract: Offshore winches are crucial in marine engineering, particularly in marine scientific research and deep-sea exploration. The use of fibre ropes presents significant opportunities for the weight reduction of winches as a consequence of the low length–strength ratio and characteristics of corrosion resistance. Nonetheless, a challenge arises in underestimating the stress load levels in load assessments of multi-layer winch systems using synthetic fibre ropes. Traditional computational methods reliant on symmetrically rotational models fall short in accurately predicting and assessing practical applications. This paper introduces a finite element analysis model based on a non-rotationally symmetric approach with four surfaces subjected to various radial pressure on account of the deformation of the fibre ropes. In the design model, sixteen stress detection paths have been incorporated to identify and confirm non-linear stresses. The outcomes of the finite element simulations have been compared with experimental results with two synthetic fibre ropes, each with distinct deformation characteristics utilised. The findings demonstrate that the application of the model aligns well with experimental results, showcasing its relevance and practical value in real-world scenarios. Precise theoretical calculations and experimental validation are pivotal to ensuring that equipment reliability and safety are maintained alongside the pursuit of light-weighting.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030409
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 410: Composition and Distribution of Microeukaryotic
           Communities in the Surface Sediments of Five Geographic Regions of Bohai
           Sea Based on 18S rDNA Amplicon Sequencing

    • Authors: Wenquan Zhang, Huameng Ge, Chengbing Song, Chengcheng Li, Shenghao Liu
      First page: 410
      Abstract: The Bohai Sea is a semi-enclosed shallow water that is influenced by both natural and anthropogenic stressors. However, the microeukaryotic communities and environmental factors that affect them in different regions remain largely unclear. We investigated microeukaryotic communities in surface sediments from five geographic regions using high-throughput sequencing of the 18S rDNA gene. The Miaodao Archipelago, Yellow River Estuary, and Central Bohai Sea had the highest Shannon and Simpson indices of the eukaryotic communities, while the Yellow River Estuary exhibited the highest Chao1 index. The microeukaryotic communities in surface sediments were mainly composed of Dinoflagellata, Bacillariophyta, Ciliophora, Cercozoa, and Protalveolata. Thalassiosira has a relatively high abundance at the Liaodong Bay and Central Bohai Sea, possessing the proportion of 41.70% and 38.10%, respectively, while Gonyaulax was the most abundant taxa in the Bohai Bay, occupying a proportion of 57.77%. Moreover, a negative correlation between diatoms and dinoflagellates was observed. Phosphorus, nitrogen, salinity, temperature, and silicate were major environmental determinants of microeukaryotic composition. Microeukaryotic communities in the surface sediments, especially for the composition and ratio of diatoms to dinoflagellates, reflected the environmental quality of marine ecosystems. Overall, these microeukaryotic community compositions provide a reliable indicator for monitoring the level of marine eutrophication in the Bohai Sea.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030410
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 411: A Two-Stage Optimisation of Ship Hull Structure
           Combining Fractional Factorial Design Technique and NSGA-II Algorithm

    • Authors: Joynal Abedin, Francis Franklin, S. M. Ikhtiar Mahmud
      First page: 411
      Abstract: The intricate nature of ships and floating structures presents a significant challenge for ship designers when determining suitable structural dimensions for maritime applications. This study addresses a critical research gap by focusing on a three-cargo hold model for a multipurpose cargo ship. The complex composition of these structures, including stiffening plates, deck plates, bottom plates, frames, and bulkheads, necessitates thorough structural analysis to facilitate effective and cost-efficient design evaluation. To address this challenge, the research utilises FEMAP-integrated NX NASTRAN software (2021.2) to assess hull girder stress. Furthermore, a novel approach is introduced, integrating the Design of Experiments (DOE) principles within Minitab 21.4.1 software to identify critical parameters affecting hull girder stress and production costs. This method determined the top five key parameters influencing hull girder stress: Hatch coaming plate, Hatch coaming top plate, Main deck plate, Shear strake plate, and Bottom plate, while also highlighting key parameters that impact production costs: the inner bottom plate, Inner side shell plate, Bottom plate, Web frame spacing, and Side shell plate. Ship design optimisation is then carried out by incorporating regression equations from Minitab software into the Non-dominated Sorting Genetic Algorithm II (NSGA-II), which is managed using Python software (PyCharm Community Editon 2020.3.1). This optimisation process yields a significant 10% reduction in both ship weight and production costs compared to the previous design, achieved through prudent adjustments in plate thickness, web frame positioning, and stiffener arrangement. The optimally designed midship section undergoes rigorous validation to ensure conformity with industry standards and classification society regulations. Necessary adjustments to inner bottom plates and double bottom side girders are made to meet these stringent requirements. This research offers a comprehensive framework for the structural optimisation of ship hulls, potentially enhancing safety, sustainability, and competitiveness within the maritime engineering industry.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030411
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 412: A Complete Coverage Path Planning Approach for
           an Autonomous Underwater Helicopter in Unknown Environment Based on VFH+
           Algorithm

    • Authors: Congcong Ma, Hongyu Zou, Xinyu An
      First page: 412
      Abstract: An Autonomous Underwater Helicopter (AUH) is a disk-shaped, multi-propelled Autonomous Underwater Vehicle (AUV), which is intended to work autonomously in underwater environments. The near-bottom area sweep in unknown environments is a typical application scenario, in which the complete coverage path planning (CCPP) is essential for AUH. A complete coverage path planning approach for AUH with a single beam echo sounder, including the initial path planning and online local collision avoidance strategy, is proposed. First, the initial path is planned using boustrophedon motion. Based on its mobility, a multi-dimensional obstacle sensing method is designed with a single beam range sonar mounted on the AUH. The VFH+ algorithm is configured for the heading decision-making procedure before encountering obstacles, based on their range information at a fixed position. The online local obstacle avoidance procedure is simulated and analyzed with variations of the desired heading direction and corresponding polar histograms. Finally, several simulation cases are set up, simulated and compared by analyzing the heading decision in front of different obstacle situations. The simulation results demonstrate the feasibility of the complete coverage path planning approach proposed, which proves that AUH completing a full coverage area sweep in unknown environments with a single beam sonar is viable.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030412
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 413: Underwater Cultural Heritage Documentation Using
           Photogrammetry

    • Authors: Alessio Calantropio, Filiberto Chiabrando
      First page: 413
      Abstract: Underwater cultural heritage (UCH) is an irreplaceable resource with intrinsic value that requires preservation, documentation, and safeguarding. Documentation is fundamental to increasing UCH resilience, providing a basis for monitoring, conservation, and management. Advanced UCH documentation and virtualization technologies are increasingly important for dissemination and visualization purposes, domain expert study, replica reproduction, degradation monitoring, and all other outcomes after a metric survey of cultural heritage (CH). Among the different metric documentation techniques, underwater photogrammetry is the most widely used for UCH documentation. It is a non-destructive and relatively inexpensive method that can produce high-resolution 3D models and 2D orthomosaics of underwater sites and artifacts. However, underwater photogrammetry is challenged by the different optical properties of water, light penetration, visibility and suspension, radiometric issues, and environmental drawbacks that make underwater documentation difficult. This paper introduces some of the recent applications of photogrammetric techniques and methods for UCH documentation, as well as the needs and shortcomings of the current state of the art.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030413
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 414: A Method for Sound Speed Profile Prediction
           Based on CNN-BiLSTM-Attention Network

    • Authors: Zhang Wei, Jin Shaohua, Bian Gang, Cui Yang, Peng Chengyang, Xia Haixing
      First page: 414
      Abstract: In response to the current challenges in efficiently acquiring sound speed profiles and ensuring their representativeness, considering the need to fully leverage historical sound speed profiles while accounting for their spatiotemporal variability, we introduce a model for sound speed profile prediction based on a CNN-BiLSTM-Attention network, which integrates a convolutional neural network (CNN), a bidirectional long short-term memory network (BiLSTM), and an attention mechanism (AM). The synergy of these components enables the model to extract the spatiotemporal features of sound speed profiles more comprehensively. Utilizing the global ocean Argo grid dataset, the model predicted the sound speed profiles of an experimental zone in the Western Pacific Ocean. In predicting sound speed profiles of a single point, the model achieved a root mean square error (RMSE), relative error (RE), and accuracy (ACC) of 0.72 m/s, 0.029%, and 0.99971, respectively, surpassing comparative models. For regional sound speed profile prediction, the mean RMSE, RE, and ACC of different water layers were 0.919 m/s, −0.016%, and 0.9995, respectively. The experimental outcomes not only confirm the high accuracy of the model, but also highlight its superiority in sound speed profile prediction, particularly as an effective compensatory approach when profile measurements are untimely or contain representational errors.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030414
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 415: Transferable Deep Learning Model for the
           Identification of Fish Species for Various Fishing Grounds

    • Authors: Tatsuhito Hasegawa, Kei Kondo, Hiroshi Senou
      First page: 415
      Abstract: The digitization of catch information for the promotion of sustainable fisheries is gaining momentum globally. However, the manual measurement of fundamental catch information, such as species identification, length measurement, and fish count, is highly inconvenient, thus intensifying the call for its automation. Recently, image recognition systems based on convolutional neural networks (CNNs) have been extensively studied across diverse fields. Nevertheless, the deployment of CNNs for identifying fish species is difficult owing to the intricate nature of managing a plethora of fish species, which fluctuate based on season and locale, in addition to the scarcity of public datasets encompassing large catches. To overcome this issue, we designed a transferable pre-trained CNN model specifically for identifying fish species, which can be easily reused in various fishing grounds. Utilizing an extensive fish species photographic database from a Japanese museum, we developed a transferable fish identification (TFI) model employing strategies such as multiple pre-training, learning rate scheduling, multi-task learning, and metric learning. We further introduced two application methods, namely transfer learning and output layer masking, for the TFI model, validating its efficacy through rigorous experiments.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030415
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 416: Marine Geological Studies of the Bay of Naples
           (Southern Tyrrhenian Sea, Italy): Revised Applications of the
           Seismo-Stratigraphic Concepts and Evolving Technologies to a Late
           Quaternary Volcanic Area

    • Authors: Gemma Aiello
      First page: 416
      Abstract: Marine geological studies of Naples Bay are discussed and reviewed, focusing on the application of the seismo-stratigraphic concepts to a Late Quaternary volcanic area. The Naples Bay represents an active volcanic area in which the interactions between volcanic and sedimentary processes controlled a complex stratigraphic architecture during the Late Quaternary period. While the volcanic processes took place in correspondence with the activity of the Somma–Vesuvius, Campi Flegrei Ischia, and Procida volcanic complexes, the sedimentary processes were controlled by the fluvial processes in the Sarno-Sebeto coastal plain and by the tectonic uplift in correspondence with the Sorrento Peninsula’s structural high Key geophysical and stratigraphic studies of the three active volcanic complexes are revised and discussed. The seismo-stratigraphic concepts applied in the geological interpretation of seismic profiles of Naples Bay are reviewed and discussed: here, the classical concepts of seismic and sequence stratigraphy have been successfully applied, but only partly, due to the occurrence of several buried volcanoes and volcanic seismic units and tephra layers, calibrated by gravity cores.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030416
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 417: In-Line Inspection (ILI) Techniques for Subsea
           Pipelines: State-of-the-Art

    • Authors: Hai Zhu, Jiawang Chen, Yuan Lin, Jin Guo, Xu Gao, Yuanjie Chen, Yongqiang Ge, Wei Wang
      First page: 417
      Abstract: Offshore oil and gas resources play a crucial role in supplementing the energy needs of human society. The crisscrossing subsea pipeline network, which serves as vital infrastructure for the storage and transportation of offshore oil and gas, requires regular inspection and maintenance to ensure safe operation and prevent ecological pollution. In-line inspection (ILI) techniques have been widely used in the detection and inspection of potential hazards within the pipeline network. This paper offers an overview of ILI techniques used in subsea pipelines, examining their advantages, limitations, applicable scenarios, and performance. It aims to provide valuable insights for the selection of ILI technologies in engineering and may be beneficial for those involved in pipeline integrity management and planning.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-26
      DOI: 10.3390/jmse12030417
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 418: Three-Dimensional Path Tracking of Over-Actuated
           AUVs Based on MPC and Variable Universe S-Plane Algorithms

    • Authors: Feng Xu, Lei Zhang, Jibin Zhong
      First page: 418
      Abstract: Autonomous Underwater Vehicles (AUVs) are widely used for the inspection of seabed pipelines. To address the issues of low trajectory tracking accuracy in AUV inspection processes due to uncertain ocean current disturbances, this paper designs a new dual-loop controller based on Model Predictive Control (MPC) and Variable Universe S-plane algorithms (S-VUD FLC, where VUD represents Variable Universe Discourse and FLC represents Fuzzy Logic Control) to achieve three-dimensional (3-D) trajectory tracking of an over-actuated AUV under uncertain ocean current disturbances. This paper uses MPC as the outer-loop position controller and S-VUD FLC as the inner-loop speed controller. The outer-loop controller generates desired speed instructions that are passed to the inner-loop speed controller, while the inner-loop speed controller generates control input and uses a direct logic thrust distribution method that approaches optimal energy consumption to distribute the thrust generated by the propellers to the over-actuated AUV, achieving closed-loop tracking of the entire trajectory. When designing the outer-loop MPC controller, the actual control input constraints of the system are considered, and control increments are introduced to reduce control model errors and the impact of uncertain external disturbances on the actual AUV model parameters. When designing the inner-loop S-VUD FLC, the strong robustness of the variable universe fuzzy controller and the easy construction characteristics of the S-plane algorithm are combined, and integral action is introduced to improve the system’s tracking accuracy. The stability of the outer loop controller is proven by the Lyapunov method, and the stability of the inner loop controller is verified by simulation. Finally, simulations show that the over-actuated AUV has fast tracking processes and high tracking result accuracy under uncertain ocean current disturbances, demonstrating the effectiveness of the designed dual-loop controller.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-27
      DOI: 10.3390/jmse12030418
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 419: Numerical Simulation of Offshore Suction Bucket
           Foundation Pullout Characteristics under Undrained Conditions

    • Authors: Pengyu Chen, Yong Chen, Zongyuan Lai, Hanqiu Liu, Ronghua Zhu
      First page: 419
      Abstract: The suction bucket jacket foundation is widely regarded as a crucial solution for constructing offshore wind farms in water depths ranging from 30 m to 50 m. When subjected to complex loads, the bucket primarily relies on vertical movement to withstand the corresponding loads. This paper investigates the undrained pullout characteristics of the bucket foundation through numerical simulation while keeping its weight constant. This study examined how the pullout capacity of the suction bucket jacket foundation is affected by the aspect ratio and soil conditions. It revealed the changing patterns of bucket–soil frictional resistance and suction during the undrained pullout process, along with their contributions to the pullout capacity of the foundation. The results indicate that the peak pullout load of the bucket increases with decreasing L/D, and the response is more pronounced in soft clay. The frictional resistance changes from upward to downward with increasing displacement, with the maximum frictional resistance occurring at the base of the foundation. The lower part of the footing has a faster response. The suction force increases with displacement, and the proportion of suction force to peak pullout tends to increase as L/D decreases. The soil failure displacement corresponding to the occurrence of the peak pullout load of the foundation lags behind the displacement at which the frictional resistance of the bucket wall stabilizes.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-27
      DOI: 10.3390/jmse12030419
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 420: Man-in-the-Loop Control and Mission Planning for
           Unmanned Underwater Vehicles

    • Authors: Mengxue Han, Jialun Wang, Jianya Yuan, Zhao Wang, Dan Yu, Qianqian Zhang, Hongjian Wang
      First page: 420
      Abstract: UUVs (unmanned underwater vehicles) perform tasks in the marine environment under direction from a commander through a mother ship control system. In cases where communication is available, a UUV task re-planning system was designed to ensure task completion despite uncertain events faced by UUVs. First, the XML language standardizes the expression of UUV task elements. Second, considering the time sequence and spatial path planning requirements of human-supervised UUV control tasks, time sequence planning based on a genetic algorithm and spatial path planning based on an improved genetic algorithm were designed to plan near-optimal approximate spatial paths for control tasks. Third, uncertainties encountered during UUV task execution were classified so that the commander could adjust according to the situation or invoke the control task re-planning algorithm to re-plan. Finally, a simulation platform was built using the QT development environment to simulate human-supervised UUV control task planning and re-planning, verifying the algorithm’s design effectiveness.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-27
      DOI: 10.3390/jmse12030420
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 421: An Equivalent Linear Method to Predict Nonlinear
           Bending Mechanics of Dredging Floating Hose String

    • Authors: Jingjing Liu, Long Yu, Xiaoyan Li, Jing Liu
      First page: 421
      Abstract: Dredging hoses are flexible and are particularly suitable for slurry transportations for mud or sand in dredging projects. To achieve sufficient bending stiffness and to prevent the pipe body from collapsing, this type of hose segment is a composite structure that is embedded with several cord reinforcement layers and steel wires in its rubber layer. To quickly evaluate the nonlinear bending mechanical properties of rubber hoses, this study proposes the equivalent stiffness method of linear superposition, which is verified by test data and numerical results. The results show that the equivalent bending stiffness method proposed in this study is in good agreement with numerical and experimental results. Then, by comparing the calculation results of the hose string, it was demonstrated that the linear stiffness superposition method proposed in this study can also accurately predict the bending mechanical behavior characteristics of string hose, and provide reliable guidance for hose design in practice.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-27
      DOI: 10.3390/jmse12030421
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 422: Installation Disturbance of Helical Anchor in
           Dense Sand and the Effect on Uplift Capacity Based on Discrete Element
           Method

    • Authors: Rong Chen, Hu Liu, Dongxue Hao, Zhaoguo Liu, Chi Yuan
      First page: 422
      Abstract: Helical anchors have been extensively employed as foundation systems for carrying tension loads due to their installation efficiency and large uplift capacity. However, the installation influences of helical anchors are still not well understood, especially for multi-helical anchors. The matrix discrete element method was used to model the process of helical anchor penetration and pull-out in dense sand to investigate the effects of the anchor geometry and advancement ratio (AR, the relative vertical movement per rotation) on soil disturbance, the particle flow mechanism, and the uplift capacity. For shallow helical anchors, the overall disturbance zone is the shape of an inverted cone after installation, while for deep helical anchors, it is funnel-shaped. The advancement ratio has significant effects on the soil particle movement and uplift capacity of helical anchors. The soil particle flow mechanism around helical plates has been identified for single-helix anchors at various advancement ratios, and for double-helix anchors, the influence of the top plate on particle movement during installation was investigated. The uplift capacities of both single- and double-helix anchors increase with the decrease in the AR (AR = 0.5~1), and the influence decreases with the anchor embedment ratio. The efficiency of double-helix anchors induced by installation is close to 1 at pitch-matched installation (AR = 1), indicating that the impact of the top plate during installation is minimal in this case.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-27
      DOI: 10.3390/jmse12030422
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 423: Numerical Simulation of Cavitation Control
           around a Circular Cylinder Using Porous Surface by Volume Penalized Method
           

    • Authors: Maryam Sadri, Ebrahim Kadivar, Ould el Moctar
      First page: 423
      Abstract: In this work, we conducted a numerical study on the cavitation flow around a circular cylinder with Re=200 and σ=1, through the implementation of a porous coating. The primary objective addressed the effectiveness of utilizing a porous surface to control cavitation. We analyzed the cavitation dynamics around the cylinder and the hydrodynamic performance at different permeability levels of the porous surfaces (K=10−12−10−10). The flow was governed by the density-based homogeneous mixture model, and the volume penalization method was used to deal with the porous layer. A high-order compact numerical method was adopted for the simulation of the cavitating flow through solving the preconditioned multiphase equations. The hydrodynamic findings demonstrated that the fluctuations in the lift coefficient decreased when the porous layer was applied. However, it is not possible to precisely express an opinion about drag because the drag coefficient may vary, either increasing or decreasing, depending on the permeability within a constant thickness of the porous layer. The results revealed that the application of a porous layer led to the effective suppression of cavitation vortex shedding. In addition, a reduction of the shedding frequency was obtained, which was accompanied by thinner and elongated vortices in the wake region of the cylinder. With the proper porous layer, the inception of the cavitation on the cylinder was suppressed, and the amplitude of pressure pulsations due to the cavitation shedding mechanism was mitigated.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-27
      DOI: 10.3390/jmse12030423
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 424: Review on the Application of Artificial
           Intelligence Methods in the Control and Design of Offshore Wind Power
           Systems

    • Authors: Dongran Song, Guoyang Shen, Chaoneng Huang, Qian Huang, Jian Yang, Mi Dong, Young Hoon Joo, Neven Duić
      First page: 424
      Abstract: As global energy crises and climate change intensify, offshore wind energy, as a renewable energy source, is given more attention globally. The wind power generation system is fundamental in harnessing offshore wind energy, where the control and design significantly influence the power production performance and the production cost. As the scale of the wind power generation system expands, traditional methods are time-consuming and struggle to keep pace with the rapid development in wind power generation systems. In recent years, artificial intelligence technology has significantly increased in the research field of control and design of offshore wind power systems. In this paper, 135 highly relevant publications from mainstream databases are reviewed and systematically analyzed. On this basis, control problems for offshore wind power systems focus on wind turbine control and wind farm wake control, and design problems focus on wind turbine selection, layout optimization, and collection system design. For each field, the application of artificial intelligence technologies such as fuzzy logic, heuristic algorithms, deep learning, and reinforcement learning is comprehensively analyzed from the perspective of performing optimization. Finally, this report summarizes the status of current development in artificial intelligence technology concerning the control and design research of offshore wind power systems, and proposes potential future research trends and opportunities.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-27
      DOI: 10.3390/jmse12030424
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 425: Environmental Performance of Bulk Carriers
           Equipped with Synergies of Energy-Saving Technologies and Alternative
           Fuels

    • Authors: Tuan Dong, Shqipe Buzuku, Mia Elg, Alessandro Schönborn, Aykut I. Ölcer
      First page: 425
      Abstract: In this study, the life cycle assessment (LCA) was used to compare the environmental performances of a conventional bulk carrier (baseline vessel) and a wind-energy-optimised bulk carrier equipped with modern on-board technologies working in synergy (future vessel). Fossil fuels was used for the baseline vessels, whereas the future vessel used liquefied biogas (LBG) and hydrotreated vegetable oil (HVO) as marine fuels. The entire life cycle phases of the vessels, namely, construction, operation, maintenance, and end-of-life, were included. The results showed that the future vessel could reduce 31.23% energy consumption, compared to the baseline model. Furthermore, the significant reduction in CO2 (48.6%), NOX (88.6%), SOX (100.0%), and black carbon (94.0%) in the tank-to-wake phase was achieved owing to energy-saving technologies working in synergy and alternative fuels. This study emphasizes the vital role of energy efficiency, technologies, and alternative fuels to achieve the zero-emission ambition of the maritime industry. Furthermore, the impacts of ship construction, maintenance, and end-of-life need to be fully considered in order to decarbonize vessel from a life cycle perspective.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-28
      DOI: 10.3390/jmse12030425
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 426: A Three-Dimensional Spatial Interpolation Method
           and Its Application to the Analysis of Oxygen Deficit in the Bohai Sea in
           Summer

    • Authors: Zihan Zhao, Junting Guo, Rushui Xiao, Wei Zheng, Yongzhi Wang, Xianqing Lv, Honghua Shi
      First page: 426
      Abstract: Dissolved oxygen (DO) plays a pivotal role in sustaining marine ecosystems. The Bohai Sea in China is a semi-enclosed sea, and oxygen-deficit events occur from time to time due to human activities. At present, there is a notable absence of any convenient and precise method for obtaining three-dimensional spatial data on DO, and the exploration of the physical mechanisms influencing oxygen deficit remains incomplete. This investigation uses the linear radial basis function (RBF-Linear) fitting method to conduct three-dimensional spatial interpolation for DO, which demonstrates minimal inaccuracy. Then, the RBF-Linear fitting method is utilized to collect a comprehensive three-dimensional spatial dataset encompassing temperature, salinity, and DO in the Bohai Sea in August from 2016 to 2018. The results indicate discernible interannual variations in the extent, area, and distribution of oxygen deficiency during summer in the Bohai Sea. Mechanism analysis reveals that intense precipitation episodes and an increase in wind stress curl exacerbate oxygen depletion. Additionally, the degree, location, and area of the two oxygen-deficit cores (off the Yellow River Estuary and off the Qinhuangdao) in the Bohai Sea are influenced by several factors, including current velocity, direction, local circulation position, and net horizontal transport rate. Furthermore, the study suggests that oxygen deficiency in the Bohai Sea region is currently in its early stages, with a limited degree of injury and a restricted range of influence. The use of a three-dimensional spatial interpolation method to create a complete DO field in three-dimensional space simplifies the research challenges associated with marine oxygen deficit. Moreover, this study holds particular significance for guiding the development of marine fisheries.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-28
      DOI: 10.3390/jmse12030426
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 427: Influence of Penetration Rate on Full-Flow
           Penetrometer Resistance in Underconsolidated Clay

    • Authors: Huanhuan Qiao, Xuening Liu, Ruixian Zhou, Huan He, Peng Peng, Zhen Jiang
      First page: 427
      Abstract: In the past few years, offshore site investigations have extensively utilized full-flow penetrometers like the Ball and T-bar penetrometers to assess penetration resistance and subsequently analyze the strength characteristics of marine clay. The relationship between penetration rate and the measured resistance to penetration and shear strength in clays has been extensively documented through full-flow penetration tests. Although previous studies have shown empirical correlations between undrained shear strength and penetration resistance, the resistance factor utilized in these correlations is typically suggested for cohesive soils that are overconsolidated or normally consolidated, rather than underconsolidated soils. The effects of penetration rate undrained penetration resistances in underconsolidated marine clay are investigated in this study by considering the outcomes of variable rate penetration testing and twitch penetration testing using full-flow penetrometers in laboratory model tests. The discussion focuses on penetration resistances depending on the normalized velocity of the full-flow penetrometers (Ball and T-bar).
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-28
      DOI: 10.3390/jmse12030427
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 428: A Review of Underwater Robot Localization in
           Confined Spaces

    • Authors: Haoyu Wu, Yinglong Chen, Qiming Yang, Bo Yan, Xinyu Yang
      First page: 428
      Abstract: Underwater robots often encounter the influence of confined underwater environments during underwater exploration. These environments include underwater caves, sunken ships, submerged houses, and pipeline structures. Robot positioning in these environments is strongly disturbed, leading not only to the failure of some commonly used positioning methods but also to an increase in errors in positioning systems that normally function well in open water. In order to overcome the limitations of positioning methods in confined underwater environments, researchers have studied different underwater positioning methods and have selected suitable methods for positioning in such environments. These methods can achieve high-precision positioning without relying on assistance from other platforms and are referred to as autonomous positioning methods. Autonomous positioning methods for underwater robots mainly include SINS/DR positioning and SLAM positioning. In addition, in recent years, researchers have developed some bio-inspired autonomous positioning methods. This article introduces applicable robot positioning methods and sensors in confined underwater environments and discusses the research directions of robot positioning methods in such environments.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-28
      DOI: 10.3390/jmse12030428
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 429: Diffusion Characteristics and Mechanisms of
           Thermal Plumes from Coastal Power Plants: A Numerical Simulation Study

    • Authors: Gaoqiang Kong, Weibing Guan
      First page: 429
      Abstract: Plumes include thermal plumes and cold plumes, of which thermal plumes receive more attention. Thermal plumes refer to the formation of high-temperature fluid structures near a heat source, which diffuse and propagate within the surrounding environment. In this study, we simulate the formation and evolution of thermal plumes using numerical modeling. Taking Wushashan Power Plant in Xiangshan Bay as an example, the diffusion characteristics of the thermal plume near the power plant were simulated by the optimized FVCOM. Combined with statistical methods and advanced mathematical models, the plume diffusion range under different working conditions was quantified, and the diffusion mechanism was studied. For example, we found that when the flow velocity is halved, the diffusion area of the surface thermal plume decreases by more than half. When the flow rate in Xiangshan Bay is reduced to 5 m3/s, the area of surface temperature rise plumes is small. Using the Richardson number, the characteristics and mechanisms of stratification/mixing near the power plant were explored. It was found that the flow field near the power plant was mainly affected by the momentum of the outlet. During a typhoon, the wind strength and path impact thermal plume diffusion via wind-driven flow.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-28
      DOI: 10.3390/jmse12030429
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 430: Analysis of Factors Affecting Vacuum Formation
           and Drainage in the Siphon-Vacuum Drainage Method for Marine Reclamation

    • Authors: Junwei Shu, Jun Wang, Kexing Chen, Qingsong Shen, Hongyue Sun
      First page: 430
      Abstract: Traditional drainage methods for marine reclamation typically consume large amounts of energy and have a negative environmental impact. The siphon-vacuum drainage method (SVD) automatically forms a vacuum and drains using less energy. It has significant potential for research and application. In this study, a theoretical model is used to calculate the vacuum formation process and drainage rate. Qualitative analysis and global sensitivity analysis were conducted to investigate the effect of various factors in the SVD on vacuum formation and drainage. The qualitative analysis suggests that modifying the length and diameter of the siphon pipe and the thickness of the sealing soil column to increase the siphon rate can improve the vacuum degree and drainage efficiency. Sobol global sensitivity analysis reveals that the sealing soil column thickness is the main factor affecting the vacuum, with a first-order sensitivity index accounting for up to 79.48%. The impact of cylinder diameter and the local resistance coefficient (0.43%) can be almost neglected. A fitting equation for estimating the maximum achievable vacuum is provided. Calculations show that the vacuum formed by the SVD can reach over 80 kPa. This work can help optimize SVD design and advance environmentally friendly marine reclamation projects.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-28
      DOI: 10.3390/jmse12030430
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 431: Sensitivity of Dynamic Response of Truss-Type
           Aquaculture Platform to Floating Body Arrangement

    • Authors: Yu Cao, Zhuo Li, Kewen Wang, Qian Ye
      First page: 431
      Abstract: Aquaculture equipment is moving from offshore areas to the deep sea to obtain a cleaner farming environment, but will suffer from a worse marine environment. Truss-type aquaculture floating platforms have gradually gained the favor of deep-sea and ocean aquaculture due to being resistant to corrosion, lightweight, easy to move, having modular assembly characteristics, and so on. Here, a modular aquaculture floating platform that is mainly composed of high-density polyethylene non-metallic pipes as a floating body, a truss structure support and a single-point mooring system is designed. The three-dimensional potential flow theory and Morison equation are applied to the motion and force prediction of discontinuous and open structures, and an evaluation method for analyzing the hydrodynamic performance of the platform system is proposed. Then, a sensitivity analysis of the dynamic response is conducted on the density and length of the bottom floating pipe arrangement of the truss-type aquaculture floating platform. The results show that the pitch motion of the heading direction and the roll motion of the beam direction have a remarkable effect on the hydrodynamics of the truss-type aquaculture floating platform, and the maximum amplitude is 12.9 deg and 10.8 deg, respectively. The effective tension under the heading direction is greater than that under the Beam direction. And the sparser the arrangement of the floating pipe is and the longer the length of the floating pipe is, the more improved the hydrodynamic performance of the floating platform will be, but the effective tension is greatly affected by the wavelength and period, so it is necessary to design the appropriate floating pipe length according to the actual marine environment. This study could provide an engineering reference for the design, analysis, and application of an aquaculture floating platform.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-28
      DOI: 10.3390/jmse12030431
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 432: Hydrogen Fuel Cell as an Electric Generator: A
           Case Study for a General Cargo Ship

    • Authors: Omer Berkehan Inal, Burak Zincir, Caglar Dere, Jean-Frédéric Charpentier
      First page: 432
      Abstract: In this study, real voyage data and ship specifications of a general cargo ship are employed, and it is assumed that diesel generators are replaced with hydrogen proton exchange membrane fuel cells. The effect of the replacement on CO2, NOX, SOX, and PM emissions and the CII value is calculated. Emission calculations show that there is a significant reduction in emissions when hydrogen fuel cells are used instead of diesel generators on the case ship. By using hydrogen fuel cells, there is a 37.4% reduction in CO2 emissions, 32.5% in NOX emissions, 37.3% in SOX emissions, and 37.4% in PM emissions. If hydrogen fuel cells are not used instead of diesel generators, the ship will receive an A rating between 2023 and 2026, a B rating in 2027, a C rating in 2028–2029, and an E rating in 2030. On the other hand, if hydrogen fuel cells are used, the ship will always remain at an A rating between 2023 and 2030. The capital expenditure (CAPEX) and operational expenditure (OPEX) of the fuel cell system are USD 1,305,720 and USD 2,470,320, respectively, for a 15-year lifetime, and the hydrogen fuel expenses are competitive at USD 260,981, while marine diesel oil (MDO) fuel expenses are USD 206,435.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-28
      DOI: 10.3390/jmse12030432
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 433: Global Investigation of Wind–Wave
           Interaction Using Spaceborne SAR Measurements

    • Authors: Huimin Li, Yijun He
      First page: 433
      Abstract: Spaceborne synthetic aperture radar (SAR) has been widely acknowledged for its advantages in collecting ocean surface measurements under all weather conditions during day and night. Despite the strongly nonlinear imaging process, SAR measurements of ocean waves provide an invaluable resource for studies into wave dynamics at the global scale. In this study, we take advantage of a newly defined parameter, the mean cross-spectrum (MACS) at a discrete wavenumber along the sensor line-of-sight axis, to further investigate the ocean wave properties. With the range peak wavenumber extracted from the MACS profile, together with the collocated model winds, the inverse wave age (iwa) is estimated. As an indicator of local wind–wave coupling, the global map of the iwa depicts a distinct pattern, with larger iwa values observed in the storm tracks. In addition to the mean, stronger variability in the iwa is also found in the storm tracks, while the iwa remains relatively steady in the trade winds with lower variability. This makes the SAR-derived iwa a significant parameter in reflecting the varying degrees of wind–wave coupling in variable geographical locations across the ocean basins. It will help to promote the practical application of SAR measurements, as well as advancing our understanding of ocean wave dynamics.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-28
      DOI: 10.3390/jmse12030433
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 434: Experimental Study of Wake Evolution under
           Vertical Staggered Arrangement of Wind Turbines of Different Sizes

    • Authors: Lidong Zhang, Zhengcong Feng, Yuze Zhao, Xiandong Xu, Jiangzhe Feng, Huaihui Ren, Bo Zhang, Wenxin Tian
      First page: 434
      Abstract: During the expansion of a wind farm, the strategic placement of wind turbines can significantly improve wind energy utilization. This study investigates the evolution of wake turbulence in a wind farm after introducing smaller wind turbines within the gaps between larger ones, focusing on aspects such as wind speed, turbulence intensity, and turbulence integral length scale. The flow field conditions are described using parameters like turbulence critical length and power spectral density, as determined through wind tunnel experiments. In these experiments, a single large wind turbine model and nine smaller wind turbine models were used to create a small wind farm unit, and pressure distribution behind the wind turbines was measured under various operating conditions. The results indicate that downstream wind speed deficits intensify as the number of small wind turbines in operation increases. The impact of these smaller turbines varies with height, with a relatively minor effect on the upper blade tip and increasingly adverse effects as you move from the upper blade tip to the lower blade tip. Through an analysis of power spectral density, the contribution of vortex motion to wake turbulence kinetic energy is further quantified. In the far wake region, the number of small wind turbines has a relatively small impact on wind speed fluctuations.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-29
      DOI: 10.3390/jmse12030434
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 435: The Influence of Refractive Index Changes in
           Water on Airborne LiDAR Bathymetric Errors

    • Authors: Xingyuan Xiao, Zhengkun Jiang, Wenxue Xu, Yadong Guo, Yanxiong Liu, Zhen Guo
      First page: 435
      Abstract: Due to the limitations of measurement equipment and the influence of factors such as the environment and target, measurement errors may occur during the data acquisition process of airborne LiDAR bathymetry (ALB). The refractive index of water is defined as the propagation ratio of the speed of light waves in a vacuum to that in water; this ratio influences not only the propagation speed of the laser pulse in water but also the propagation direction of the laser pulse entering water. Therefore, the influence of refractive index changes in water on the ALB errors needs to be analyzed. To this end, the principle of ALB is first briefly introduced. Then, the calculation method for the refractive index of water is described with Snell’s law and an empirical formula. Finally, the influence of refractive index changes on ALB errors is analyzed using the derived formula at the water–air interface and in the water column. The experimental results showed that in a constant elevation of 50 m for a bathymetric floor, the refractive index changes in water caused by temperature, salinity, and depth are less than 0.001. The maximum bathymetric error and maximum planimetric error caused by the refractive index changes at the water–air interface are 0.036 m and 0.015 m, respectively. The ALB errors caused by refractive index changes in the water column are relatively low, and the water column does not need to be layered to calculate the ALB errors. The influence of refractive index changes in water on the ALB error is minimal, accounting for only a small proportion of all bathymetric errors. Thus, it is necessary to determine whether the effect of the ALB error due to refractive index changes in water needs to be corrected based on the accuracy requirements of the data acquisition. This study and analysis can provide a reference basis for correcting ALB errors.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-29
      DOI: 10.3390/jmse12030435
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 436: Fishing Vessel Bulbous Bow Hydrodynamics—A
           Numerical Reverse Design Approach

    • Authors: Héctor Rubén Díaz Ojeda, Sebastian Oyuela, Roberto Sosa, Alejandro Daniel Otero, Francisco Pérez Arribas
      First page: 436
      Abstract: Naval hydrodynamics typically focus on reducing ship resistance, which can be achieved by incorporating a bulbous bow. This feature is commonly used in the merchant fleet and smaller vessels, such as fishing boats, to minimize wave-making resistance. However, it is important to note that the use of a bulbous bow may not always be necessary or effective in all ship designs. In some cases, fishing ship designs may include a bulbous bow that is not optimized due to the use of procedures and methods intended for larger merchant ships or based on past experience. This study examines the effect of different bow designs, including the bulbous bow, on ship resistance in calm water, with a focus on a typical Argentinian trawler fishing vessel. The objective of this research is to assess the hydrodynamics of various designs for a particular ship by modifying its vessel lines. Firstly, the bulbous bow is removed, and then the reduction in ship resistance achieved by the bulbous bow under different load conditions and speeds is evaluated by comparing the vessel with and without the bulbous bow. The numerical analysis is performed using OpenFOAM, and the results are validated through towing tank experiments. This research indicates that the performance of the bulbous bow varies under different conditions. Therefore, it is recommended to conduct an initial study and a full evaluation of the design and operation alternatives.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-29
      DOI: 10.3390/jmse12030436
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 437: Point-to-Point-Based Optimization Method of
           Ballast Water Allocation for Revolving Floating Cranes with Experimental
           Verification

    • Authors: Xiaobang Wang, Yang Yu, Siyu Li, Jie Zhang, Zhijie Liu
      First page: 437
      Abstract: The Revolving Floating Crane (RFC) is a specialized engineering vessel crucial for offshore lifting operations, such as offshore platform construction and deep-water salvaging. It boasts impressive lifting capacity, good adaptability to various environmental conditions, and high operational efficiency. Conventionally, the safety and stability of RFC operations heavily depend on manual ballast water allocation, which is directly influenced by factors such as personnel status and sea conditions. These manual operations often result in reduced lifting efficiency, higher energy consumption, and compromised operational safety. In response, this paper introduces a ballast water-allocation approach based on the Point-to-Point (PTP) theory for the intelligent operation process of the RFC. The fundamental principles of the PTP theory are analyzed, and a method tailored to optimize ballast water allocation for RFC is proposed. Considering the unique characteristics of the ballast system and the specific requirements of lifting operations, an optimization model for PTP-based ballast water allocation is established. Numerical experiments are conducted to verify the efficacy and reliability of the proposed method. Comparing it to the conventional approaches, the results demonstrate a notable 17.75% reduction in energy consumption and an impressive 73.49% decrease in decision-making time, showcasing the superiority of the proposed approach. Finally, the engineering feasibility of the PTP-based optimization method for ballast water allocation is validated through actual lifting experiments, underscoring its potential to enhance RFC operations.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-03-01
      DOI: 10.3390/jmse12030437
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 438: Astronomical Time Scale of the Late Pleistocene
           in the Northern South China Sea Based on Carbonate Deposition Record

    • Authors: Chunhui Zhang, Wanyi Zhang, Chengjun Zhang, Liwei Zheng, Shiyi Yan, Yuanhao Ma, Wei Dang
      First page: 438
      Abstract: Variations in solar insolation caused by changes in the Earth’s orbit—specifically its eccentricity, obliquity, and precession—can leave discernible marks on the geologic record. Astrochronology leverages these markers to establish a direct connection between chronological measurements and different facets of climate change as recorded in marine sediments. This approach offers a unique window into the Earth’s climate system and the construction of high-resolution, continuous time scales. Our study involves comprehensive bulk carbonate analyses of 390 discrete samples from core SCS1, which was retrieved from the deep-sea floor of the northern South China Sea. By utilizing carbonate stratigraphic data, we have developed a carbonate stratigraphic age model. This was achieved by aligning the carbonate sequence from core SCS1 with the established carbonate standard stratigraphic time scale of the South China Sea. Subsequently, we construct an astronomically tuned time scale based on this age model. Our findings indicate that sediment records in this core have been predominantly influenced by a 20,000-year cycle (precession cycle) throughout the Late Pleistocene. We have developed an astronomical time scale extending back approximately 110,000 years from the present, with a resolution of 280 years, by tuning the carbonate record to the precession curve. Time-domain spectral analysis of the tuned carbonate time series, alongside the consistent comparability of the early Holocene low-carbonate event (11–8 kyr), underscores the reliability of our astronomical time scale. Our age model exposes intricate variations in carbonate deposition, epitomizing a typical “Pacific-type” carbonate cycle. Previous research has illustrated that precession forcing predominantly influences productivity changes in the South China Sea. The pronounced precession-related cycle observed in our record suggests that changes in productivity significantly impact carbonate content in the area under study. Furthermore, the clear precession period identified in the carbonate record of core SCS1 reflects the response of low-latitude processes to orbital parameters, implying that carbonate deposition and preservation in core SCS1 are chiefly influenced by the interplay between the Intertropical Convergence Zone (ITCZ) and the monsoon system within the precession band. Our astronomical time scale is poised to enhance paleoceanographic, paleoclimatic, and correlation studies further. Additionally, the independent evidence we provide for using proxy records for astronomical age calibration of marine sediments lends additional support to similar methods of astronomical tuning.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-03-01
      DOI: 10.3390/jmse12030438
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 439: Application of Artificial Intelligence in
           Maritime Transportation

    • Authors: Xinqiang Chen, Dongfang Ma, Ryan Wen Liu
      First page: 439
      Abstract: Maritime logistics and supply chain management have become more complicated due to economic globalization development [...]
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-03-01
      DOI: 10.3390/jmse12030439
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 440: Examining the Impact of Long-Term
           Industrialization on the Trace Metal Contaminants Distribution in Seawater
           of the Pula Bay, Croatia

    • Authors: Ozren Grozdanić, Ana-Marija Cindrić, Iva Finderle, Dario Omanović
      First page: 440
      Abstract: In this study, we examined for the first time the spatio-temporal distribution of trace metal (TM) contaminants (Zn, Cd, Pb, Cu, Ni and Co) in the seawater column of Pula Bay. The bay has been known for decades as one of the most industrialized regions on the Croatian side of the Adriatic. Water samples were collected at 20 sites (at two depths) in four different seasons. The main physico-chemical parameters and DOC were measured along the TMs. The spatial distribution clearly showed that areas with industrial and nautical activities are sources of Zn, Pb and Cu, while no increase was observed for Cd, Ni and Co. Compared to the reference area outside the bay, the increase in dissolved concentrations ranged from a factor of 1.1 for Ni and Co to 8.5 for Pb. A clear difference in TM concentrations was observed between seasons, with concentrations being higher in warmer periods than in colder periods. The potential bioavailability/toxicity of TMs was examined using a passive sampling technique: diffusive gradients in thin films (DGT). In addition, a single-factor pollution index based on the available EQSs was used for both the dissolved TMs and DGT to assess the potential risk to the environment.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-03-01
      DOI: 10.3390/jmse12030440
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 441: Moderate Anthropogenic Noise Exposure Does Not
           Affect Navy Bottlenose Dolphin (Tursiops truncatus) Whistle Rates

    • Authors: Jessica J. Sportelli, Kelly M. Heimann, Brittany L. Jones
      First page: 441
      Abstract: Bottlenose dolphins (Tursiops truncatus) rely on frequency- and amplitude-modulated whistles to communicate, and noise exposure can inhibit the success of acoustic communication through masking or causing behavioral changes in the animal. At the US Navy Marine Mammal Program (MMP) in San Diego, CA, dolphins are housed in netted enclosures in the San Diego Bay and exposed to noise from vessels, unmanned underwater vehicles, and other remote sensing devices. The acoustic behavior of 20 dolphins was monitored and whistle rates during noise events were quantified. Whistle rates during the onset of the event (i.e., the first 5 min) did not significantly differ from the pre-onset (5 min immediately preceding). Whistle rates were also not significantly different for the entire duration of the event compared to a matched control period. The noise’s frequency range (i.e., control, mid-frequency (0–20 kHz) or high-frequency (21–80 kHz)), signal-to-noise ratio, and sound pressure level were not significantly related to the dolphins’ whistle rate. Considering this is a location of frequent and moderate noise output, these results lend support to established guidelines on anthropogenic noise exposure for cetaceans, suggesting that moderate noise exposure levels may not impact communication efforts in bottlenose dolphins.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-03-01
      DOI: 10.3390/jmse12030441
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 442: Improving Water Quality in a Sea Bay by
           Connecting Rivers on Both Sides of a Harbor

    • Authors: Yuning Chi, Wenming Zhang, Yanling Liu, Xiaoyu Zhang, Wanqing Chi, Bing Shi
      First page: 442
      Abstract: Improving water quality is imperative for many sea bays, including Laizhou Bay, China, to achieve sustainable marine development. In 2010, two 17.3 km long sand-retaining embankments were built in southwestern Laizhou Bay, which weakened the nearshore hydrodynamics and seriously impacted the water quality. To mitigate this issue, this study proposes connecting the two rivers on both sides of the embankments to improve the hydrodynamics and thus water exchange in the sea bay. The effectiveness was examined with a numerical model using Mike 21, which was validated for both tidal current velocity and direction at six monitoring locations in the sea bay. The results show that over 53% of the core research area displays an increase (0.0–0.4 m/s) in tidal current speed after the connection, primarily in and around the Haihengwei Fishing Port. Meanwhile, the Eulerian residual currents in the Haihengwei Fishing Port, Mi River estuary and Bailang River estuary become substantially larger (with a maximum increase of 0.16 m/s). In addition, the net transport distance of particles released near the connection increases by up to 39.89 km in one month. Overall, this case study demonstrates that connecting rivers next to a harbor can effectively improve hydrodynamics and thus improve water quality in the bay.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-03-01
      DOI: 10.3390/jmse12030442
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 443: Sessile Biofouling on Electrolytic Carbonated
           Structures: Stages of Colonization and Succession

    • Authors: Alejandro Carmona-Rodríguez, Carlos Antón, Miguel-Ángel Climent, Pedro Garcés, Vicente Montiel, Alfonso A. Ramos-Esplá
      First page: 443
      Abstract: The ecological succession has been widely studied by means of biofouling assemblages among different substrates, and mainly targeted in early stages on artificial ones. The present study focuses on biofouling that colonizes carbonated structures, a material similar to the natural substrate produced by the electrolysis of seawater, which is relatively very little studied. We have observed the colonization of sessile macrofouling of the port of Alicante (SE Spain, Western Mediterranean) on two types of substrates (electrolytic carbonated and steel) over 12 months of succession. The assemblages of both substrates have been analyzed by means of diversity indexes and multivariate analysis (PERMANOVA and SIMPER) in order to see the differences over time. The carbonated substrate has presented a community with higher values of biological diversity, structure and complexity, although the differences in species composition between substrates are not evident during all immersion periods. Thus, these results seem to indicate that, even after 12 months of immersion, communities are still in a dynamic successional stage.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-03-01
      DOI: 10.3390/jmse12030443
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 444: Research on Structural Collapse of a
           Containership under Combined Bending–Torsion by Oblique Waves

    • Authors: Weiqin Liu, Qilu Zou, Yaqiang Zhang, Yong Nie, Xuemin Song
      First page: 444
      Abstract: Large waves cause a great number of collapsed-ship accidents, resulting in the loss of many lives and properties. It has been found that most of these collapses are caused by encountering oblique waves. As a result, the ship structure experiences a complex collapse under combined bending and torsion. This paper utilizes a numerical hydroelasto-plastic approach, coupling CFD (Computational Fluid Dynamics) with the nonlinear FEM (Finite-Element Method), to study the structural collapse of a containership in oblique waves. First, a 4600 TEU containership was selected to study its collapse mechanism under oblique waves. Second, a hydroelasto-plastic numerical coupling of CFD and nonlinear FEM is used to co-calculate the wave loads and structural collapse of containership. The hydrodynamic model is constructed and used to solve wave loads in the CFD solver, and a nonlinear FEM model of containership with finer meshes is also modeled to solve the structural collapses, including plasticity and buckling. Third, several oblique-wave cases involving heading angles of 120°, 135°, 150°, and 180° are determined and calculated. Typical cases are discussed for time-domain stress histories and collapsed courses. Finally, the influence of oblique-wave parameters on structural collapse is discussed, and the collapse mechanism of containerships under the action of oblique waves is obtained, which provides a new understanding of ship structure design.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-03-01
      DOI: 10.3390/jmse12030444
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 445: Identification of Suitable Mangrove Distribution
           Areas and Estimation of Carbon Stocks for Mangrove Protection and
           Restoration Action Plan in China

    • Authors: Bingbin Feng, Yancheng Tao, Xiansheng Xie, Yingying Qin, Baoqing Hu, Renming Jia, Lianghao Pan, Wenai Liu, Weiguo Jiang
      First page: 445
      Abstract: Mangrove forests are significant blue carbon pools on the Earth with strong carbon sequestration capacity and play an important role in combating climate change. To improve the capacity of regional carbon sinks, China has implemented a Special Action Plan for Mangrove Protection and Restoration (2020–2025). In this context, based on the MaxEnt model, this study analyzed the important environmental factors affecting the distribution of mangrove forests, combined with the planning objectives and carbon density parameters of different regions; assessed the habitat suitability areas of China’s mangrove forests; and predicted their future carbon stock potential. The results showed the following: (1) Elevation was the most important factor affecting the overall distribution of mangrove forests in China, and the optimal elevation of mangrove distribution was 0.52 m. (2) The most suitable areas of mangrove forests in China were mainly distributed in Hainan, Guangxi, and Guangdong, which had great potential for carbon stock. Danzhou Bay and Hongpai Harbor in Hainan, Lianzhou Bay in Guangxi, and the Huangmao Sea in Guangdong are potential areas for habitat suitability but are not yet under high levels of protection. (3) Achieving the goals of this action plan was expected to increase carbon stocks by 4.13 Tg C. Other suitable areas not included in this plan could still increase carbon stocks by 7.99 Tg C in the long term. The study could provide a scientific basis for siting mangrove restoration areas and developing efficient management policies.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-03-01
      DOI: 10.3390/jmse12030445
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 446: Ocean-Mixer: A Deep Learning Approach for
           Multi-Step Prediction of Ocean Remote Sensing Data

    • Authors: Sai Wang, Guoping Fu, Yongduo Song, Jing Wen, Tuanqi Guo, Hongjin Zhang, Tuantuan Wang
      First page: 446
      Abstract: The development of intelligent oceans requires exploration and an understanding of the various characteristics of the oceans. The emerging Internet of Underwater Things (IoUT) is an extension of the Internet of Things (IoT) to underwater environments, and the ability of IoUT to be combined with deep learning technologies is a powerful technology for realizing intelligent oceans. The underwater acoustic (UWA) communication network is essential to IoUT. The thermocline with drastic temperature and density variations can significantly limit the connectivity and communication performance between IoUT nodes. To more accurately capture the complexity and variability of ocean remote sensing data, we first sample and analyze ocean remote sensing datasets and provide sufficient evidence to validate the temporal redundancy properties of the data. We propose an innovative deep learning approach called Ocean-Mixer. This approach consists of three modules: an embedding module, a mixer module, and a prediction module. The embedding module first processes the location and attribute information of the ocean water and then passes it to the subsequent modules. In the mixing module, we apply a temporal decomposition strategy to eliminate redundant information and capture temporal and channel features through a self-attention mechanism and a multilayer perceptron (MLP). The prediction module ultimately discerns and integrates the temporal and channel relationships and interactions among various ocean features, ensuring precise forecasting. Numerous experiments on ocean temperature and salinity datasets show that Mixer-Ocean performs well in improving the accuracy of time series prediction. Mixer-Ocean is designed to support multi-step prediction and capture the changes in the ocean environment over a long period, thus facilitating efficient management and timely decision-making for innovative ocean-oriented applications, which has far-reaching significance for developing and conserving marine resources.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-03-01
      DOI: 10.3390/jmse12030446
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 447: Editorial of the Special Issue “Novel
           Oil–Water Separation Technologies Applied in Marine Environmental
           Science”

    • Authors: Qiang Yang
      First page: 447
      Abstract: The marine environment, a vital component of the Earth’s ecosystem, is increasingly threatened by pollution, and notably by oil spills [...]
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-03-01
      DOI: 10.3390/jmse12030447
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 448: Statistical Analysis of Ice Load on Icebreaker
           Ship Based on Stochastic Ice Fields

    • Authors: Liang Li, Guangchun Han, Shunying Ji
      First page: 448
      Abstract: Accurately assessing ice loads is a fundamental issue in the field of structural design for ships in ice-covered regions. In this paper, we conducted research on extreme ice load estimation for icebreaking ships, combining stochastic theory with numerical simulation. Firstly, using sea ice data from the Arctic region of the United States National Snow and Ice Data Center, a stochastic ice field model was established under Arctic sea ice conditions using non-parametric estimation and the rejection sampling method, and ice field data were generated stochastically. Then, based on the stochastic ice field data, a three-dimensional numerical model of the interaction between the ice field and the ship hull was established, and the reliability of the numerical model was verified by experimental results. Finally, based on the numerical model of the interaction between the ice field and the ship hull, asymptotic methods were used to study the extreme ice load estimation in different parts of the ship hull, revealing the variation law of the extreme ice load in different parts of the ship hull. This study provides basic theory and technical support for the structural design of ships in polar regions and has engineering application value.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-03-01
      DOI: 10.3390/jmse12030448
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 449: Numerical Study on Wave Dissipation and Mooring
           Force of a Horizontal Multi-Cylinder Floating Breakwater

    • Authors: Zhipeng Zang, Zhuo Fang, Kuan Qiao, Limeng Zhao, Tongming Zhou
      First page: 449
      Abstract: A three-dimensional numerical model was established based on ANSYS-AQWA (R19.0) software for the purpose of analyzing the hydrodynamic characteristics of a floating breakwater. This study examines three distinct floating breakwaters with different cross-sectional designs in order to evaluate their respective wave dissipation capabilities. It is suggested that the horizontal multi-cylinder floating breakwater exhibits a superior ability to dissipate waves when compared to both the single-cylinder and square pontoon configurations and can be deemed the most advantageous shielding strategy for potential engineering applications. Subsequently, this study examines the effects of influential parameters, including a large cylinder diameter, a small cylinder diameter, the angular position of the small cylinder, and the height and period of the incident wave, on the wave transmission coefficient. An empirical formula for the wave transmission coefficient was derived based on the numerical results. Additionally, the effects of influential parameters, including wind speed, current velocity, incident wave height and period, and water depth, on the maximum total mooring force were investigated. Furthermore, an empirical formula for the maximum total mooring force is proposed for practical implementation in engineering.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-03-01
      DOI: 10.3390/jmse12030449
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 450: Joint Inversion of Sea Surface Wind and Current
           Velocity Based on Sentinel-1 Synthetic Aperture Radar Observations

    • Authors: Jingbei Sun, Huimin Li, Wenming Lin, Yijun He
      First page: 450
      Abstract: Spaceborne synthetic aperture radar (SAR) has been proven to be a useful technique for observing the sea surface wind and current over the open ocean given its all-weather data-gathering capability and high spatial resolution. In addition to the commonly used radar return magnitude quantified by normalized radar cross section (NRCS), the Doppler centroid anomaly (DCA) has added another dimension of information. In this study, we combine the NRCS and DCA for a joint inversion of wind and surface current information using a Bayesian method. SAR-estimated Doppler is corrected by a series of steps, including the removal of scalloping effect and land correction. The cost function of this inversion scheme is constructed based on NRCS, DCA, and a background model wind. The retrieved wind results show the quality of performance through comparison with the in situ buoy measurements, showing a mean bias and a root-mean-square error (RMSE) of 0.33 m/s and 1.45 m/s for wind speed and 6.94° and 35.74° for wind direction, respectively. The correlation coefficients for wind speed and direction reach 0.931 and 0.661, respectively. Based on the obtained wind field, the line-of-sight velocity of the sea surface current is then derived by removing the wind contribution using the empirical model. The results show a consistent spatial pattern relative to the high-frequency radars, with the comparison relative to the drifter-measured current velocity exhibiting a mean bias of 0.02 m/s and RMSE of 0.32 m/s, demonstrating the reliability of the proposed inversion scheme. Such results will serve as a prototype for future spaceborne sensors to combine the radar return and Doppler information for the joint retrieval of wind vector and surface current velocity. This technique could be readily extended to the radar configuration of rotating beams for monitoring winds and current vectors.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-03-02
      DOI: 10.3390/jmse12030450
      Issue No: Vol. 12, No. 3 (2024)
       
  • JMSE, Vol. 12, Pages 351: Dynamic Positioning Control of Large Ships in
           Rough Sea Based on an Improved Closed-Loop Gain Shaping Algorithm

    • Authors: Chunyu Song, Teer Guo, Jianghua Sui, Xianku Zhang
      First page: 351
      Abstract: In order to solve the problem of the dynamic positioning control of large ships in rough sea and to meet the need for fixed-point operations, this paper proposes a dynamic positioning controller that can effectively achieve large ships’ fixed-point control during Level 9 sea states (wind force Beaufort No. 10). To achieve a better control effect, a large ship’s forward motion is decoupled to establish a mathematical model of the headwind stationary state. Meanwhile, the closed-loop gain shaping algorithm is combined with the exact feedback linearization algorithm to design the speed controller and the course-keeping controller. This effectively solves the problem of strong external interferences impacting the control system in rough seas and guarantees the comprehensive index of robustness performance. In this paper, three large ships—the “Mariner”, “Taian kou”, and “Galaxy”—are selected as the research objects for simulation research and the final fixing error is less than 10 m. It is proven that the method is safe, feasible, practical, and effective, and provides technical support for the design and development of intelligent marine equipment for use in rough seas.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-18
      DOI: 10.3390/jmse12020351
      Issue No: Vol. 12, No. 2 (2024)
       
  • JMSE, Vol. 12, Pages 352: Sonar Image Target Detection Based on Simulated
           Stain-like Noise and Shadow Enhancement in Optical Images under Zero-Shot
           Learning

    • Authors: Jier Xi, Xiufen Ye
      First page: 352
      Abstract: There are many challenges in using side-scan sonar (SSS) images to detect objects. The challenge of object detection and recognition in sonar data is greater than in optical images due to the sparsity of detectable targets. The complexity of real-world underwater scanning presents additional difficulties, as different angles produce sonar images of varying characteristics. This heterogeneity makes it difficult for algorithms to accurately identify and detect sonar objects. To solve these problems, this paper presents a novel method for sonar image target detection based on a transformer and YOLOv7. Thus, two data augmentation techniques are introduced to improve the performance of the detection system. The first technique applies stain-like noise to the training optical image data to simulate the real sonar image environment. The second technique adds multiple shadows to the optical image and 3D data targets to represent the direction of the target in the sonar image. The proposed method is evaluated on a public sonar image dataset, and the experimental results demonstrate that the proposed method outperforms the state-of-the-art methods in terms of accuracy and speed. The experimental results show that our method achieves better precision.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-18
      DOI: 10.3390/jmse12020352
      Issue No: Vol. 12, No. 2 (2024)
       
  • JMSE, Vol. 12, Pages 353: Review on Sensors for Sustainable and Safe
           Maritime Mobility

    • Authors: Giovanni Briguglio, Vincenzo Crupi
      First page: 353
      Abstract: The increasingly stringent requirements—in terms of limiting pollutants and the constant need to make maritime transport safer—generated the necessity to foresee different solutions that are original. According to the European Maritime Safety Agency, the total number of reported marine casualties and incidents is 21.173 over the period 2014–2021, with a yearly average of 2.647 casualties and incidents. According to the same source, 495 cases of pollution were reported in the period from 2014 to 2021. Marine pollution by ships’ fuel and other pollutants is linked to 64.2% of all pollution. It is mandatory to offer a new kind of ship that can exploit new technologies to increase safety for people and onboard goods. It has been found that existing marine structures for maritime mobility do not have essential sensors for avoiding emergency situations such as flooding, oil spills, or health situations requiring efficient monitoring. In addition, there is a lack of legislation defining the insertion of unmanned vehicles into the actual marine infrastructure. This review highlighted the strengths and weaknesses of sensors in the maritime sector, intensifying areas of improvement for future challenges, such as sensor energy efficiency, data processing, sensor fusion methodologies, and accurate sea state description with environmental monitoring by means of unmanned vehicles.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-19
      DOI: 10.3390/jmse12020353
      Issue No: Vol. 12, No. 2 (2024)
       
  • JMSE, Vol. 12, Pages 354: The Mediterranean Zoanthid Parazoanthus
           axinellae as a Novel Source of Antimicrobial Compounds

    • Authors: Loredana Stabili, Stefano Piraino, Lucia Rizzo
      First page: 354
      Abstract: Marine bioprospecting is a dynamic research field that explores the oceans and their biodiversity as noteworthy sources of new bioactive compounds. Anthozoans are marine animals belonging to the Cnidaria phylum characterized by highly specialized mechanosensory cells used both for defence against predators and prey capture. Here, high concentration of cnidocysts have been isolated from the Mediterranean zoanthid coral Parazoanthus axinellae (Schmidt, 1862) and their antimicrobial potential has been investigated. The cnidocyst extract exerted significant antibacterial activity against some human pathogens capable of developing resistance to conventional antibiotics such as Streptococcus agalactiae and Coccus sp., and against several Vibrio species, including some microbial strains for humans and farmed fish, such as Vibrio alginolyticus, Vibrio anguillarum, Vibrio fischeri, Vibrio harveyi, and Vibrio vulnificus. Results have been discussed in light of both the ecological aspects and biotechnological value of the cnidocyst extract in the nutritional, nutraceutical, and pharmaceutical fields.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-18
      DOI: 10.3390/jmse12020354
      Issue No: Vol. 12, No. 2 (2024)
       
  • JMSE, Vol. 12, Pages 355: Autonomous Marine Vehicle Operations

    • Authors: Xiao Liang, Rubo Zhang, Xingru Qu
      First page: 355
      Abstract: The world has witnessed the rapid development of autonomous marine vehicles,such as surface vehicles and underwater vehicles, which have created fruitful innovative approaches to previously unsolvable problems in marine and ocean engineering [...]
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-19
      DOI: 10.3390/jmse12020355
      Issue No: Vol. 12, No. 2 (2024)
       
  • JMSE, Vol. 12, Pages 356: Machine Learning-Based Approach to Identifying
           Fall Risk in Seafarers Using Wearable Sensors

    • Authors: Jungyeon Choi, Brian A. Knarr, Jong-Hoon Youn, Kwang Yoon Song
      First page: 356
      Abstract: Falls on a ship cause severe injuries, and an accident falling off board, referred to as “man overboard” (MOB), can lead to death. Thus, it is crucial to accurately and timely detect the risk of falling. Wearable sensors, unlike camera and radar sensors, are affordable and easily accessible regardless of the weather conditions. This study aimed to identify the fall risk level (i.e., high and low risk) among individuals on board using wearable sensors. We collected walking data from accelerometers during the experiment by simulating the ship’s rolling motions using a computer-assisted rehabilitation environment (CAREN). With the best features selected by LASSO, eight machine learning (ML) models were implemented with a synthetic minority oversampling technique (SMOTE) and the best-tuned hyperparameters. In all ML models, the performance in classifying fall risk showed overall a good accuracy (0.7778 to 0.8519), sensitivity (0.7556 to 0.8667), specificity (0.7778 to 0.8889), and AUC (0.7673 to 0.9204). Logistic regression showed the best performance in terms of the AUC for both training (0.9483) and testing (0.9204). We anticipate that this study will effectively help identify the risk of falls on ships and aid in developing a monitoring system capable of averting falls and detecting MOB situations.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-19
      DOI: 10.3390/jmse12020356
      Issue No: Vol. 12, No. 2 (2024)
       
  • JMSE, Vol. 12, Pages 357: Research on the Drift Prediction of Marine
           Floating Debris: A Case Study of the South China Sea Maritime Drift
           Experiment

    • Authors: Lin Mu, Haiwen Tu, Xiongfei Geng, Fangli Qiao, Zhihui Chen, Sen Jia, Ruifei Zhu, Tianyu Zhang, Zhi Chen
      First page: 357
      Abstract: Annually, hundreds of individuals tragically lose their lives at sea due to shipwrecks or aircraft accidents. For search and rescue personnel, the task of locating the debris of a downed aircraft in the vastness of the ocean presents a formidable challenge. A primary task these teams face is determining the search area, which is a critical step in the rescue operation. The movement of aircraft wreckage on the ocean surface is extremely complex, influenced by the combined effects of surface winds, waves, and currents. Establishing an appropriate drift motion prediction model is instrumental in accurately determining the search area for the wreckage. This article initially conducts maritime drift observation experiments on wreckage, and based on the results of these experiments, analyzes the drift characteristics and patterns of the debris. Subsequently, employing a wealth of observational experimental data, three types of drift prediction models for the wreckage are established using the least squares method. These models include the AP98 model, the dynamics model, and an improved model. In conclusion, the effectiveness and accuracy of the three models is evaluated and analyzed using Monte Carlo techniques. The results indicate that the probability of positive crosswind leeway (CWL) is 47.4%, while the probability of negative crosswind leeway (CWL) is 52.6%. The jibing frequency is 7.7% per hour, and the maximum leeway divergence angle observed is 40.4 degrees. Among the three drift prediction models, the refined AP98 drift model demonstrates the highest forecasting precision. The findings of this study offer a more accurate drift prediction model for the search of an aircraft lost at sea. These results hold significant guiding importance for maritime search and rescue operations in the South China Sea.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-19
      DOI: 10.3390/jmse12020357
      Issue No: Vol. 12, No. 2 (2024)
       
  • JMSE, Vol. 12, Pages 358: Agent-Guided Non-Local Network for Underwater
           Image Enhancement and Super-Resolution Using Multi-Color Space

    • Authors: Rong Wang, Yonghui Zhang, Yulu Zhang
      First page: 358
      Abstract: The absorption and scattering of light in water usually result in the degradation of underwater image quality, such as color distortion and low contrast. Additionally, the performance of acquisition devices may limit the spatial resolution of underwater images, resulting in the loss of image details. Efficient modeling of long-range dependency is essential for understanding the global structure and local context of underwater images to enhance and restore details, which is a challenging task. In this paper, we propose an agent-guided non-local attention network using a multi-color space for underwater image enhancement and super-resolution. Specifically, local features with different receptive fields are first extracted simultaneously in the RGB, Lab, and HSI color spaces of underwater images. Then, the designed agent-guided non-local attention module with high expressiveness and lower computational complexity is utilized to model long-range dependency. Subsequently, the results from the multi-color space are adaptively fused with learned weights, and finally, the reconstruction block composed of deconvolution and the designed non-local attention module is used to output enhanced and super-resolution images. Experiments on multiple datasets demonstrated that our method significantly improves the visual perception of degraded underwater images and efficiently reconstructs missing details, and objective evaluations confirmed the superiority of our method over other state-of-the-art methods.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-19
      DOI: 10.3390/jmse12020358
      Issue No: Vol. 12, No. 2 (2024)
       
  • JMSE, Vol. 12, Pages 359: Advances in Offshore Wind

    • Authors: Dongran Song, Tianhui Fan, Qingan Li, Young Hoon Joo
      First page: 359
      Abstract: Wind energy has emerged as one of the most effective solutions to address global energy crises and environmental degradation, owing to its clean and abundant resources [...]
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-19
      DOI: 10.3390/jmse12020359
      Issue No: Vol. 12, No. 2 (2024)
       
  • JMSE, Vol. 12, Pages 360: Types and Evolution of the Miocene Reefs Based
           on Seismic Data in the Beikang Basin, South China Sea

    • Authors: Zhen Yang, Guozhang Fan, Wei Yan, Xuefeng Wang, Guoqing Zhang, Zhili Yang, Zuofei Zhu, Yuanze Zhang, Huai Cheng, Hongxun Tian, Li Li, Qiang Zhang
      First page: 360
      Abstract: During the Miocene, several reefs formed in the Beikang Basin, South China Sea, which may be potential targets for hydrocarbon exploration. This is due to the environment that developed as a result of the collision, splitting, and splicing of the Nansha Block, which was influenced by the Neogene expansion of the area. However, studies on the types, distribution, controlling factors, and evolution stages of these reefs are scarce. In this study, we used high-resolution seismic data and extensive well-drilling records to gain insights into the evolution of reefs in this particular area. Six distinct types of reefs, namely, the point reef, the platform-edge reef, the block reef, the bedded reef, the pinnacle reef, and the atoll reef, were identified based on our data. These reefs underwent four stages of development. During the initial stage, a few small-sized point reefs emerged in the basin and experienced significant growth during the early Middle Miocene. In the flourishing stage, the reefs predominantly thrived around the Central Uplift and Eastern Uplift areas. In the recession stage, the reefs began to deteriorate during the late Middle Miocene period as a result of the rapid increase in relative sea level caused by tectonic subsidence. In the submerged stage, since the Late Miocene, as the relative sea level continued to rise steadily over time, many reefs that had previously flourished surrounding the Central Uplift and Eastern Uplift areas became submerged underwater, with only a handful of atoll reefs surviving near islands located on the Eastern Uplift. This study indicated the presence of a significant number of well-preserved reefs in the Beikang Basin that have experienced minimal subsequent diagenesis and therefore exhibit high potential as reservoirs for oil and gas exploration.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2024-02-19
      DOI: 10.3390/jmse12020360
      Issue No: Vol. 12, No. 2 (2024)
       
 
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  Subjects -> EARTH SCIENCES (Total: 771 journals)
    - EARTH SCIENCES (527 journals)
    - GEOLOGY (94 journals)
    - GEOPHYSICS (33 journals)
    - HYDROLOGY (29 journals)
    - OCEANOGRAPHY (88 journals)

OCEANOGRAPHY (88 journals)

Showing 1 - 79 of 79 Journals sorted by number of followers
Deep Sea Research Part II: Topical Studies in Oceanography     Hybrid Journal   (Followers: 28)
Hydrobiology     Open Access   (Followers: 28)
Estuaries and Coasts     Hybrid Journal   (Followers: 25)
Limnology and Oceanography     Hybrid Journal   (Followers: 25)
Deep Sea Research Part I : Oceanographic Research Papers     Hybrid Journal   (Followers: 23)
Journal of Physical Oceanography     Hybrid Journal   (Followers: 21)
Frontiers in Marine Science     Open Access   (Followers: 20)
New Zealand Journal of Marine and Freshwater Research     Hybrid Journal   (Followers: 19)
Journal of Marine Biology & Oceanography     Hybrid Journal   (Followers: 19)
Progress in Oceanography     Hybrid Journal   (Followers: 18)
Journal of Marine Sciences     Open Access   (Followers: 18)
Coastal Engineering     Hybrid Journal   (Followers: 16)
Advances in Oceanography and Limnology     Open Access   (Followers: 16)
Maritime Studies     Open Access   (Followers: 13)
Journal of Oceanography     Hybrid Journal   (Followers: 12)
Advances in Statistical Climatology, Meteorology and Oceanography     Open Access   (Followers: 10)
Bulletin of Marine Science     Full-text available via subscription   (Followers: 9)
Atmospheric and Oceanic Science Letters     Open Access   (Followers: 9)
Fisheries Oceanography     Hybrid Journal   (Followers: 8)
International Journal of Oceanography     Open Access   (Followers: 8)
Physical Oceanography     Hybrid Journal   (Followers: 6)
Open Journal of Marine Science     Open Access   (Followers: 6)
Limnology and Oceanography: Fluids and Environments     Full-text available via subscription   (Followers: 6)
Journal of Oceanography and Marine Science     Open Access   (Followers: 6)
Oceanography : Open Access     Open Access   (Followers: 6)
Limnology and Oceanography: Methods     Hybrid Journal   (Followers: 6)
Paleoceanography and Paleoclimatology     Full-text available via subscription   (Followers: 5)
Marine Science     Open Access   (Followers: 5)
Journal of Oceanology and Limnology     Hybrid Journal   (Followers: 4)
Journal of Marine Science and Engineering     Open Access   (Followers: 4)
Ocean Yearbook Online     Hybrid Journal   (Followers: 4)
Limnology and Oceanography Letters     Open Access   (Followers: 4)
African Journal of Marine Science     Hybrid Journal   (Followers: 3)
Journal of Marine Science and Application     Hybrid Journal   (Followers: 3)
Oceanology     Hybrid Journal   (Followers: 3)
Journal of Operational Oceanography     Hybrid Journal   (Followers: 3)
Journal of Coastal Development     Open Access   (Followers: 3)
Ciencias Marinas     Open Access   (Followers: 3)
Journal of Aquatic Sciences     Full-text available via subscription   (Followers: 3)
Journal of Ocean Engineering and Marine Energy     Hybrid Journal   (Followers: 3)
Limnology and Oceanography e-Lectures     Open Access   (Followers: 3)
Development and Applications of Oceanic Engineering     Open Access   (Followers: 2)
Indian Journal of Geo-Marine Sciences     Open Access   (Followers: 2)
Regional Studies in Marine Science     Hybrid Journal   (Followers: 2)
Limnology and Oceanography: Bulletin     Hybrid Journal   (Followers: 2)
Mediterranean Marine Science     Open Access   (Followers: 2)
Annals of Marine Science     Open Access   (Followers: 2)
Annals of Limnology and Oceanography     Open Access   (Followers: 2)
Journal of Ocean University of China (English Edition)     Hybrid Journal   (Followers: 1)
Scientia Marina     Open Access   (Followers: 1)
Western Indian Ocean Journal of Marine Science     Open Access   (Followers: 1)
Marine Technology Society Journal     Full-text available via subscription   (Followers: 1)
Journal of Ocean Engineering and Science     Open Access   (Followers: 1)
Ocean Life     Open Access   (Followers: 1)
Acta Aquatica : Aquatic Sciences Journal     Open Access   (Followers: 1)
Journal of Ocean Engineering and Technology     Open Access   (Followers: 1)
Tropical Oceanography     Open Access   (Followers: 1)
Marine Systems & Ocean Technology     Hybrid Journal   (Followers: 1)
Marine Life Science & Technology     Hybrid Journal   (Followers: 1)
Coastal Engineering Proceedings : Proceedings of the International Conference on Coastal Engineering     Open Access   (Followers: 1)
Asian Journal of Fisheries and Aquatic Research     Open Access  
Thalassas : An International Journal of Marine Sciences     Hybrid Journal  
Oceans     Open Access  
Aquatic Research     Open Access  
Jurnal Kelautan Tropis     Open Access  
Depik Jurnal Ilmu-Ilmu Perairan, Pesisir dan Perikanan     Open Access  
Journal of Agricultural and Marine Sciences     Open Access  
Turkish Journal of Maritime and Marine Sciences     Open Access  
Arquivos de Ciências do Mar     Open Access  
Scientific Drilling     Open Access  
Jurnal Kelautan : Indonesian Journal of Marine Science and Technology     Open Access  
Oceanologia     Open Access  
Revista de Gestão Costeira Integrada     Open Access  
Revista Ciencias Marinas y Costeras     Open Access  
Egyptian Journal of Aquatic Research     Open Access  
China Ocean Engineering     Hybrid Journal  
Revista de Biología Marina y Oceanografía     Open Access  
Latin American Journal of Aquatic Research     Open Access  
Acta Oceanologica Sinica     Hybrid Journal  
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JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


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