Journal of Marine Science and Engineering

22 pages, 8852 KiB

Open AccessArticle

Sequence Stratigraphy, Sedimentology, and Reservoir Characteristics of the Middle Cretaceous Mishrif Formation, South Iraq

by Leifu Zhang, Wenqi Zhang, Yong Li, Benbiao Song, Dawang Liu, Ya Deng, Jiacheng Xu and Yuning Wang

J. Mar. Sci. Eng. 2023, 11(6), 1255; https://doi.org/10.3390/jmse11061255 - 20 Jun 2023

Cited by 2 | Viewed by 1916

Abstract

The Cenomanian–Early Turonian Mishrif Formation is a great contributor to oil production in Iraq. Integrating petrographic, mineralogical, and wireline logging data from 52 wells, this study provides an improved understanding of the sequence stratigraphy, depositional evolution, and reservoir characteristics of the Mishrif Formation [...] Read more.

The Cenomanian–Early Turonian Mishrif Formation is a great contributor to oil production in Iraq. Integrating petrographic, mineralogical, and wireline logging data from 52 wells, this study provides an improved understanding of the sequence stratigraphy, depositional evolution, and reservoir characteristics of the Mishrif Formation in the Mesopotamian Basin, south Iraq. Five types of facies associations are classified: lagoon, shoal, rudist bioherm, shallow marine, and deep marine. Such a classification allows convenient differentiation and interpretation of wireline logs. A sequence stratigraphic framework including five third-order sequences (Mhf 1 to Mhf 5) for the Mishrif Formation is established mainly using wireline logging data of close-distance wells, with the aid of cores and thin sections. Two end-member depositional evolution stages are recognized, from clinoform-like progradational shoal complexes in Mhf 1 within a shallow marine environment, to tidal channels in Mhf 2–3 within a lagoon environment. For Mhf 4–5, abrupt changes in facies associations from north to south indicate the development of an intra-shelf basin where organic-rich mudstones directly overlie the shallow marine grainstone shoals and lagoonal wackestones. Reservoir characteristics and compartmentalization are directly controlled by the sequence stratigraphic framework. Sequence boundaries are featured by wackestones and mudstones overprinted by cementation; they are regionally correlatable and work as regional barriers. Shoal complexes in Mhf 1 and tidal channels in Mhf 2–3 are the main reservoir units. Mudstones and wackestones are intra-reservoir baffles and become more frequently developed towards the south, reflecting the increasing water depth towards south. The characterization of the tidal channels, clinoform-like shoals, and intrashelf basinal deposits in the current study could benefit later development of the Mishrif Formation. Full article

(This article belongs to the Special Issue High-Efficient Exploration and Development of Oil & Gas from Ocean)

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19 pages, 7231 KiB

Open AccessEditor’s ChoiceArticle

Fatigue Analysis of Inter-Array Power Cables between Two Floating Offshore Wind Turbines Including a Simplified Method to Estimate Stress Factors

by Dennis Beier, Anja Schnepf, Sean Van Steel, Naiquan Ye and Muk Chen Ong

J. Mar. Sci. Eng. 2023, 11(6), 1254; https://doi.org/10.3390/jmse11061254 - 20 Jun 2023

Cited by 2 | Viewed by 3058

Abstract

The use of floating offshore wind farms for electrical energy supply is expected to rise significantly over the coming years. Suspended inter-array power cables are a new design to connect floating offshore wind turbines (FOWTs) with shorter cable lengths than conventional setups. The [...] Read more.

The use of floating offshore wind farms for electrical energy supply is expected to rise significantly over the coming years. Suspended inter-array power cables are a new design to connect floating offshore wind turbines (FOWTs) with shorter cable lengths than conventional setups. The present study investigates the fatigue life of a suspended power cable with attached buoys connecting two spar-type FOWTs. Typical environmental conditions for the North Sea are applied. The nonlinear bending behavior of the power cable is considered in the analysis. Fatigue assessment is performed using the numerical software OrcaFlex based on stress factors obtained from cross-section analysis. An effective method for obtaining the stress factors is proposed for early engineering design stages and compared with the finite element software UFLEX simulation results. The simplified method delivers similar results for axial tension loads and conservative results for bending loads compared with results obtained from the finite element software. Stress components resulting from curvature variation are identified as the main contributors to fatigue damage. The most critical locations along the power cable for fatigue life are close to the hang-off points. Full article

(This article belongs to the Special Issue Innovative Development of Offshore Wind Technology)

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14 pages, 801 KiB

Open AccessArticle

Four-Dimensional Variational Data Assimilation and Sensitivity of Ocean Model State Variables to Observation Errors

by Victor Shutyaev, Vladimir Zalesny, Valeriy Agoshkov, Eugene Parmuzin and Natalia Zakharova

J. Mar. Sci. Eng. 2023, 11(6), 1253; https://doi.org/10.3390/jmse11061253 - 20 Jun 2023

Cited by 2 | Viewed by 886

Abstract

The use of Four-Dimensional variational (4D-Var) data assimilation technology in the context of sea dynamics problems, with a sensitivity analysis of model results to observation errors, is presented. The technology is applied to a numerical model of ocean circulation developed at the Marchuk [...] Read more.

The use of Four-Dimensional variational (4D-Var) data assimilation technology in the context of sea dynamics problems, with a sensitivity analysis of model results to observation errors, is presented. The technology is applied to a numerical model of ocean circulation developed at the Marchuk Institute of Numerical Mathematics, Russian Academy of Sciences (INM RAS), with the use of the splitting method and complemented by 4D-Var data assimilation with covariance matrices of background and observation errors. The variational data assimilation involves iterative procedures to solve inverse problems so as to correct sea surface heat fluxes for the model under consideration. An algorithm is formulated to study the sensitivity of the model outputs, considered as output functions after assimilation, to the observation errors. The algorithm reveals the regions where the output function gradient is the largest for the average sea surface temperature (SST) in a selected area, obtained by assimilation. In the numerical experiments, a 4D variational problem of SST assimilation for the Baltic Sea area is solved. Full article

(This article belongs to the Section Physical Oceanography)

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20 pages, 10565 KiB

Open AccessArticle

Research on Construction and Application of Ocean Circulation Spatial–Temporal Ontology

by Hao Zhang, Anmin Zhang, Chenxu Wang, Liuyang Zhang and Shuai Liu

J. Mar. Sci. Eng. 2023, 11(6), 1252; https://doi.org/10.3390/jmse11061252 - 20 Jun 2023

Viewed by 1135

Abstract

Due to the absence of a comprehensive knowledge system for modeling ocean circulation, there is ambiguity and diversity in the semantic expression of ocean circulation. This makes it difficult to organize and share relevant spatiotemporal data effectively. This paper addresses the issue of [...] Read more.

Due to the absence of a comprehensive knowledge system for modeling ocean circulation, there is ambiguity and diversity in the semantic expression of ocean circulation. This makes it difficult to organize and share relevant spatiotemporal data effectively. This paper addresses the issue of ocean circulation by introducing ontological theory and methodology based on a comprehensive analysis of domain knowledge. Through a comprehensive analysis of the conceptual and relational characteristics of different elements, we define classes, properties, spatiotemporal relationships, and inference conditions with which to formally express concepts and relationships in ocean circulation, and finally complete the construction of ocean circulation ontology. The formal expression of the Equatorial Counter Current is presented as an example with which to validate the effectiveness of ontological construction. Additionally, an ontology-based knowledge base of ocean circulation is proposed. The construction framework is described, and several examples of knowledge base queries are also illustrated. The results demonstrate that this ontology can effectively represent the relevant knowledge within ocean circulation and provide a meaningful reference for investigating knowledge sharing and semantic integration within this field. Full article

(This article belongs to the Special Issue Application of Advanced Technologies in Maritime Safety)

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17 pages, 1920 KiB

Open AccessArticle

Effect of Void Content on the Mechanical Properties of GFRP for Ship Design

by Jaewon Jang, Maydison, Yeonjun Kim, Zhiqiang Han and Daekyun Oh

J. Mar. Sci. Eng. 2023, 11(6), 1251; https://doi.org/10.3390/jmse11061251 - 19 Jun 2023

Cited by 1 | Viewed by 1354

Abstract

Defects such as voids in composite materials often degrade the mechanical properties of laminates. Even if these materials are manufactured based on the design requirements, there is a possibility of instability occurring in these composite structures. In this study, several prototypes were developed [...] Read more.

Defects such as voids in composite materials often degrade the mechanical properties of laminates. Even if these materials are manufactured based on the design requirements, there is a possibility of instability occurring in these composite structures. In this study, several prototypes were developed based on changes in composite ship design conditions (glass fiber weight fraction and fabric combination type) using a hand lay-up approach. The fabrication quality was quantitatively defined using the burn-off test, and statistical analysis was performed. A combination of chopped strand mat and woven roving material laminates possessed relatively less void content in the entire glass content (G_c) region (30–70 wt%) compared to a chopped strand mat single-material laminate. The effect was more pronounced in the high-G_c region (50–70 wt%) than that in the normal-G_c region (30–50 wt%). The composite hull plate can be designed seamlessly according to changes in fabrication quality. To ensure safety, the thickness of the laminate must be greater than that specified in the ISO standards, regardless of the combination type in the normal-G_c region. As a result of the void content considered, the flexural strength in the single laminate decreased by 15.02%. Furthermore, 3.33% of the flexural strength calculation decreased in the combined laminate compared to that in the ISO rules. Thus, a single CSM material can be designed to be thicker than a combined-material laminate with the same G_c, while considering the void content on the mechanical properties. Full article

(This article belongs to the Section Ocean Engineering)

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4 pages, 188 KiB

Open AccessEditorial

Damage Stability of Ships

by Pekka Ruponen and Apostolos Papanikolaou

J. Mar. Sci. Eng. 2023, 11(6), 1250; https://doi.org/10.3390/jmse11061250 - 19 Jun 2023

Viewed by 1216

Abstract

Ensuring adequate damage stability of ships is essential in ship design and directly contributes to their safe operation [...] Full article

(This article belongs to the Special Issue Damage Stability of Ships)

4 pages, 191 KiB

Open AccessEditorial

Subsea Pipelines

by Bai-Qiao Chen and C. Guedes Soares

J. Mar. Sci. Eng. 2023, 11(6), 1249; https://doi.org/10.3390/jmse11061249 - 19 Jun 2023

Viewed by 1472

Abstract

A subsea pipeline (also known as an offshore pipeline or submarine pipeline) is a pipeline that is laid on the seabed or inside a specially constructed trench [...] Full article

(This article belongs to the Special Issue Subsea Pipelines)

19 pages, 6620 KiB

Open AccessArticle

Migration of Leaked Oil Vapor in Underground Water-Sealed Oil Storage Cavern Considering the Influence of Fractures

by Dong Tang, Huixiang Jian, Min Song and Zhongming Jiang

J. Mar. Sci. Eng. 2023, 11(6), 1248; https://doi.org/10.3390/jmse11061248 - 19 Jun 2023

Viewed by 1119

Abstract

During the operation of underground water-sealed oil storage caverns, a large amount of oil vapor is generated due to volatilization. Oil vapor can easily leak into the surrounding rock, and fractures in the surrounding rock are usually the dominant channels for oil vapor [...] Read more.

During the operation of underground water-sealed oil storage caverns, a large amount of oil vapor is generated due to volatilization. Oil vapor can easily leak into the surrounding rock, and fractures in the surrounding rock are usually the dominant channels for oil vapor leakage. To study the influence of fractures on oil vapor leakage and migration in underground water-sealed oil storage caverns during the oil storage period, a gas–liquid two-phase flow model of the fracture–pore dual medium in fractured rock mass was established. The program was implemented on the COMSOL platform by using weak-form PDE (partial differential equation). Then, taking an underground water-sealed cavern of an oil reserve as an example, the influence of the characteristic parameters of a single fracture on the evolution process of oil vapor leakage and migration during the oil storage period of the underground water-sealed oil storage cavern was studied. The results were further applied to the Huangdao underground oil depot project. The results show that the spatial distribution of oil vapor leakage is mainly affected by fractures. Through parameter sensitivity analysis, it was found that the geometric characteristic parameters of fractures will have a certain impact on the migration field of oil vapor leakage in underground caverns. Specifically, fracture permeability (k_f), fracture width (d_f), and fracture inclination (θ) are positively correlated with oil vapor leakage parameters (oil vapor leakage range and leakage volume), while the distance between the fracture and the middle cavern (s) is negatively correlated with oil vapor leakage parameters (oil vapor leakage range and leakage volume). The relative influence of fracture geometry parameters on the migration process of oil vapor leakage during the oil storage period of the underground water-sealed oil storage cavern is in the following order: k_f> d_f> s > θ. Engineering application shows that the existence of fractures affects the spatial distribution of oil vapor leakage and migration, and the relationship between oil vapor leakage parameters and oil storage operation time is a positive power function. The gas–liquid two-phase flow model of the fracture–pore dual medium in fractured rock mass developed in this study could offer a numerical simulation tool to assess and mitigate the risk of oil vapor leakage. The research conclusions can provide some references for related problems encountered in similar projects. Full article

(This article belongs to the Special Issue Sustainable Use of Marine Resources: Green Construction, Safe Operation and Environmental Impact of Offshore Projects)

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17 pages, 4072 KiB

Open AccessArticle

Assessment of Water Quality in a Coastal Region of Sea Dike Construction in Korea and the Impact of Low Dissolved Oxygen Concentrations on pH Changes

by Yong-Woo Lee, Yong Hwa Oh, Sang Heon Lee, Dohyun Kim and DongJoo Joung

J. Mar. Sci. Eng. 2023, 11(6), 1247; https://doi.org/10.3390/jmse11061247 - 19 Jun 2023

Cited by 2 | Viewed by 1595

Abstract

To investigate the factors affecting water quality in coastal regions with sea dike constructions, surface water outside a sea dike was monitored for six years from 2015 to 2020 in the Saemangeum region of Korea. Statistical analyses of the six years of high-frequency [...] Read more.

To investigate the factors affecting water quality in coastal regions with sea dike constructions, surface water outside a sea dike was monitored for six years from 2015 to 2020 in the Saemangeum region of Korea. Statistical analyses of the six years of high-frequency measurements revealed that the water quality in this system was predominantly governed by natural processes followed by pollutant inputs as the secondary influencing factor. Severe dissolved oxygen (DO) depletion was observed in the surface waters during warm periods, probably owing to the advection of DO-depleted water from elsewhere to the surface layer. Based on the apparent oxygen utilization (AOU)–pH relationship (r = 0.52, n = 1837), the maximum AOU (180 µM) led to a pH decrease from 8.04 to 7.50, which was considerably lower than the estimated value of 7.72. This extra pH drop was probably due to a reduction in the buffering capacity associated with increased CO₂ in the water column originating from the atmosphere and in situ production, as well as local water column redox reactions associated with benthic inputs of reduced chemical species. Overall, persistent DO depletion with ongoing eutrophication/hypoxia could accelerate ocean acidification in Korean coastal waters, which could be more acute in coastal regions with artificial coastal constructions. Full article

(This article belongs to the Section Chemical Oceanography)

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28 pages, 39250 KiB

Open AccessArticle

Submarine Geomorphology and Sedimentary Features around the Egadi Islands (Western Mediterranean Sea)

by Mauro Agate, Christina Lombardo, Claudio Lo Iacono, Attilio Sulli, Sabrina Polizzi, Renato Chemello and Paolo Emanuele Orrù

J. Mar. Sci. Eng. 2023, 11(6), 1246; https://doi.org/10.3390/jmse11061246 - 19 Jun 2023

Viewed by 1170

Abstract

In this paper, the physiography, geomorphological features, and sedimentary bedforms of the offshore Egadi Islands (Italy) have been illustrated and mapped through an integrated analysis of high-resolution bathymetric, seismo-acoustic, and sedimentological data. The study area is characterized by a wide, up to 25 [...] Read more.

In this paper, the physiography, geomorphological features, and sedimentary bedforms of the offshore Egadi Islands (Italy) have been illustrated and mapped through an integrated analysis of high-resolution bathymetric, seismo-acoustic, and sedimentological data. The study area is characterized by a wide, up to 25 km, continental shelf which is separated by a NNW-trending linear incision, the Marettimo Channel, along which several erosional and depositional features have been detected and mapped. Sedimentary prograding wedges were detected at water depths between 100–125 m along the shelf margin, which accumulated during the sea-level fall and lowstand stages of the last glacio-eustatic cycle (post- MIS 5.5). This study detected several slope breaks defining scarps across the continental shelf, which were interpreted as coastal cliffs that originated during the post-LGM eustatic sea-level rise. Several fields of different types of sedimentary bedforms, including 2-D and 3-D hydraulic dunes and sorted bedforms, were found across the continental shelf, providing evidence of a high hydrodynamic regime affecting the seafloor. Further on, this study recognized erosive and depositional features related to bottom currents (contourites) in the Marettimo Channel. These findings provide a better understanding of the morpho-sedimentary evolution of the Egadi Islands offshore in the latest Quaternary. Moreover, they offer essential scientific support for effectively managing the most valuable priority habitats for conservation, such as the Posidonia oceanica meadow and coralline algae bioconstructions (Coralligenous habitat). Full article

(This article belongs to the Special Issue Marine Geological Mapping)

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26 pages, 10537 KiB

Open AccessArticle

Fishing Behavior Detection and Analysis of Squid Fishing Vessel Based on Multiscale Trajectory Characteristics

by Fan Zhang, Baoxin Yuan, Liang Huang, Yuanqiao Wen, Xue Yang, Rongxin Song and Pieter van Gelder

J. Mar. Sci. Eng. 2023, 11(6), 1245; https://doi.org/10.3390/jmse11061245 - 18 Jun 2023

Viewed by 1327

Abstract

Accurate fishing activity detection from the trajectories of fishing vessels can not only achieve high-precision fishery management but also ensure the reasonable and sustainable development of marine fishery resources. This paper proposes a new method to detect fishing vessels’ fishing activities based on [...] Read more.

Accurate fishing activity detection from the trajectories of fishing vessels can not only achieve high-precision fishery management but also ensure the reasonable and sustainable development of marine fishery resources. This paper proposes a new method to detect fishing vessels’ fishing activities based on the defined local dynamic parameters and global statistical characteristics of vessel trajectories. On a local scale, the stop points and points of interest (POIs) in the vessel trajectory are extracted. Voyage extraction can then be conducted on this basis. After that, multiple characteristics based on motion and morphology on a global scale are defined to construct a logistic regression model for fishing behavior detection. To verify the effectiveness and feasibility of the method, vessel trajectory data, and fishing log data collected from Chinese ocean squid fishing vessels in Argentine waters in 2020 are integrated for fishing operation detection. Multiple evaluation metrics show that the proposed method can provide robust and accurate recognition results. Moreover, further analysis of the temporal and spatial distribution and seasonal changes in squid fishing activities in Argentine waters has been performed. A more refined assessment of the fishing activities of individual fishing vessels can also be provided quantitatively. All the results above can benefit the regulation of fishing activities. Full article

(This article belongs to the Special Issue Data/Knowledge-Driven Behaviour Analysis for Maritime Autonomous Surface Ships—2nd Edition)

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18 pages, 824 KiB

Open AccessArticle

Adaptive Sliding Mode Control for Unmanned Surface Vehicles with Predefined-Time Tracking Performances

by Tao Jiang, Yan Yan and Shuang-He Yu

J. Mar. Sci. Eng. 2023, 11(6), 1244; https://doi.org/10.3390/jmse11061244 - 17 Jun 2023

Cited by 4 | Viewed by 1518

Abstract

This paper is concerned with the trajectory tracking control of unmanned surface vehicles (USVs) subject to input quantization, actuator faults and dead zones. In scenarios with dense marine facilities, there are constraints on the tracking performance and convergence time of USVs. First, the [...] Read more.

This paper is concerned with the trajectory tracking control of unmanned surface vehicles (USVs) subject to input quantization, actuator faults and dead zones. In scenarios with dense marine facilities, there are constraints on the tracking performance and convergence time of USVs. First, the designed control signal is quantized by a hysteresis quantizer to reduce the transmission rate. Second, to guarantee the transient and steady-state tracking performance of the USV, a prescribed performance control technology with a predefined settling time is employed. Third, a predefined-time adaptive sliding mode control (SMC) method is designed by integrating the auxiliary function and the barrier function. Moreover, the lumped uncertainties caused by quantization, actuator faults, and dead zones are simultaneously processed using control gain based on barrier function. The proposed control method guarantees that the tracking error and sliding variable converge to the corresponding predefined bounds within a predefined time. The predefined bounds are independent of the upper bound on the lumped uncertainty. The stability of the controlled system is proven via the Lyapunov theorem. Finally, the effectiveness of the designed controller is verified by numerical simulations. Full article

(This article belongs to the Section Ocean Engineering)

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23 pages, 742 KiB

Open AccessArticle

Robust IMM Filtering Approach with Adaptive Estimation of Measurement Loss Probability for Surface Target Tracking

by Chen Chen, Weidong Zhou and Lina Gao

J. Mar. Sci. Eng. 2023, 11(6), 1243; https://doi.org/10.3390/jmse11061243 - 17 Jun 2023

Viewed by 1215

Abstract

A suitable jump Markov system (JMS) filtering approach provides an efficient technique for tracking surface targets. In complex surface target tracking situations, due to the joint influences of lost measurements with an unknown probability and heavy-tailed measurement noise (HTMN), the estimation accuracy of [...] Read more.

A suitable jump Markov system (JMS) filtering approach provides an efficient technique for tracking surface targets. In complex surface target tracking situations, due to the joint influences of lost measurements with an unknown probability and heavy-tailed measurement noise (HTMN), the estimation accuracy of conventional interacting multiple model (IMM) methods may be seriously degraded. Aiming to address the filtering issues in JMSs with HTMNs and random measurement losses, this paper presents an IMM filtering approach with the adaptive estimation of unknown measurement loss probability. In this study, we assumed that the measurement noises obey student’s t-distributions and then proposed Bernoulli random variables (BRVs) to characterize the random measurement loss. Notably, by converting the two likelihood functions from the weighted sum form to exponential multiplication, we established hierarchical Gaussian state space models to directly utilize the variational inference method. The system state vectors, unknown distribution parameters, BRVs, and unknown measurement loss probabilities were estimated simultaneously according to the variational Bayesian inference in the IMM framework. The results of maneuvering target tracking simulations verified that the presented filtering approach demonstrated superior estimation accuracy compared to existing IMM filters. Full article

(This article belongs to the Special Issue Optimal Maneuvering and Control of Ships)

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25 pages, 4293 KiB

Open AccessArticle

A Ship Route Planning Method under the Sailing Time Constraint

by Yuankui Li, Jinlong Cui, Xinyu Zhang and Xuefeng Yang

J. Mar. Sci. Eng. 2023, 11(6), 1242; https://doi.org/10.3390/jmse11061242 - 17 Jun 2023

Cited by 1 | Viewed by 1622

Abstract

This paper realizes the simultaneous optimization of a vessel’s course and speed for a whole voyage within the estimated time of arrival (ETA), which can ensure the voyage is safe and energy-saving through proper planning of the route and speed. Firstly, a dynamic [...] Read more.

This paper realizes the simultaneous optimization of a vessel’s course and speed for a whole voyage within the estimated time of arrival (ETA), which can ensure the voyage is safe and energy-saving through proper planning of the route and speed. Firstly, a dynamic sea area model with meteorological and oceanographic data sets is established to delineate the navigable and prohibited areas; secondly, some data are extracted from the records of previous voyages, to train two artificial neural network models to predict fuel consumption rate and revolutions per minute (RPM), which are the keys to route optimization. After that, speed configuration is introduced to the optimization process, and a simultaneous optimization model for the ship’s course and speed is proposed. Then, based on a customized version of the A* algorithm, the optimization is solved in simulation. Two simulations of a ship crossing the North Pacific show that the proposed methods can make navigation decisions in advance that ensure the voyage’s safety, and compared with a naive route, the optimized navigation program can reduce fuel consumption while retaining an approximately constant time to destination and adapting to variations in oceanic conditions. Full article

(This article belongs to the Special Issue Recent Developments and Knowledge in Intelligent and Safe Marine Navigation)

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16 pages, 7629 KiB

Open AccessArticle

Physics-Based Modelling for On-Line Condition Monitoring of a Marine Engine System

by Chao Fu, Kuan Lu, Qian Li, Yuandong Xu, Fengshou Gu, Andrew D. Ball and Zhaoli Zheng

J. Mar. Sci. Eng. 2023, 11(6), 1241; https://doi.org/10.3390/jmse11061241 - 17 Jun 2023

Cited by 1 | Viewed by 1268

Abstract

The engine system is critical for a marine vehicle, and its performance significantly affects the efficiency and safety of the whole ship. Due to the harsh working environment and the complex system structure, a marine system is prone to have many kinds of [...] Read more.

The engine system is critical for a marine vehicle, and its performance significantly affects the efficiency and safety of the whole ship. Due to the harsh working environment and the complex system structure, a marine system is prone to have many kinds of novelties and faults. Timely detection of faults via effective condition monitoring is vital for such systems, avoiding serious damage and economic loss. However, it is difficult to realize online monitoring because of the limitations of measurement and health monitoring methods. In this paper, a marine engine system simulator is set up with enhanced sensory placement for static and dynamic data collection. The test rig and processing for static and dynamic data are described. Then, a physics-based multivariate modeling method is proposed for the health monitoring of the system. Case studies are carried out considering the misfire fault and the exhaust valve leakage fault. In the misfire fault test, the exhaust gas temperature of the misfired cylinder dropped from the confidence interval 100–150 °C to 70–80 °C and the head vibration features decreased from the confidence interval 900–1300 m/s² to around 200–300 m/s². For the exhaust valve leakage fault, the engine body vibration main bearing impact RMS increased nearly 10 times. Comparisons between the model-predicted confidence interval and measured data reveal that the proposed model based on the fault-related static and dynamic features successfully identified the two faults and their positions, proving the effectiveness of the proposed framework. Full article

(This article belongs to the Special Issue Advances in Marine Structures)

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21 pages, 2672 KiB

Open AccessArticle

New Insight into the Genus Cladocroce (Porifera, Demospongiae) Based on Morphological and Molecular Data, with the Description of Two New Species

by Marco Bertolino, Carlo Cerrano, Giorgio Bavestrello, Do Cong Thung, Laura Núñez-Pons, Francesca Rispo, Jana Efremova, Valerio Mazzella, Daisy Monica Makapedua and Barbara Calcinai

J. Mar. Sci. Eng. 2023, 11(6), 1240; https://doi.org/10.3390/jmse11061240 - 16 Jun 2023

Viewed by 18321

Abstract

During scientific expeditions in Indonesia and Vietnam, several sponge specimens belonging to the genus Cladocroce were collected. The integration of morphological and molecular analyses, incorporating species delimitation models (ABGD, ASAP, and bPTP) and phylogenetic approaches using three molecular markers (COI, 28S, and 18S–ITS1–5.8S–ITS2–28S), [...] Read more.

During scientific expeditions in Indonesia and Vietnam, several sponge specimens belonging to the genus Cladocroce were collected. The integration of morphological and molecular analyses, incorporating species delimitation models (ABGD, ASAP, and bPTP) and phylogenetic approaches using three molecular markers (COI, 28S, and 18S–ITS1–5.8S–ITS2–28S), allowed us to discriminate three congeneric species. Two of these species (C. burapha and C. pansinii sp. nov.) were supported by morphological and molecular data, whereas a third species (C. lamellata sp. nov.) was delimited by morphological data only. We formally describe two new species, C. pansinii sp. nov. and C. lamellata sp. nov. C. aculeata is a newly recorded species for Indonesia and the first documented finding after the original description. The re-examination of the type material of C. burapha, and indirectly the molecular approach, allowed us to confirm that C. burapha lives in sympatry with C. pansinii sp. nov. in Vietnam and with C. lamellata in Indonesia. Thanks to these findings, we relocated the paratype of C. burapha to the new species described here, i.e., C. pansinii sp. nov. Full article

(This article belongs to the Special Issue The 10th Anniversary of JMSE - Recent Advances in Section Marine Biology)

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15 pages, 9390 KiB

Open AccessArticle

Wind Speed Analysis Method within WRF-ARW Tropical Cyclone Modeling

by Evgeny Poplavsky, Alexandra Kuznetsova and Yuliya Troitskaya

J. Mar. Sci. Eng. 2023, 11(6), 1239; https://doi.org/10.3390/jmse11061239 - 16 Jun 2023

Viewed by 1161

Abstract

This paper presents an analysis of a new method for retrieving the parameters of the atmospheric boundary layer in hurricanes. This method is based on the approximation of the upper parabolic part of the wind speed profile and the retrieval of the lower [...] Read more.

This paper presents an analysis of a new method for retrieving the parameters of the atmospheric boundary layer in hurricanes. This method is based on the approximation of the upper parabolic part of the wind speed profile and the retrieval of the lower logarithmic part. Based on the logarithmic part, the friction velocity, near-surface wind speed and the aerodynamic drag coefficient are obtained. The obtained data are used for the verification of the modeling data in the WRF-ARW model. The case of the Irma hurricane is studied. Different configurations of the model are tested, which differ in the use of physical parameterizations. The difference of wind profiles in various sectors of the hurricane is studied. Full article

(This article belongs to the Section Ocean and Global Climate)

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20 pages, 3857 KiB

Open AccessReview

The Distribution of Pseudodiaptomus marinus in European and Neighbouring Waters—A Rolling Review

by Marco Uttieri, Olga Anadoli, Elisa Banchi, Marco Battuello, Şengül Beşiktepe, Ylenia Carotenuto, Sónia Cotrim Marques, Alessandra de Olazabal, Iole Di Capua, Kirsten Engell-Sørensen, Alenka Goruppi, Tamar Guy-Haim, Marijana Hure, Polyxeni Kourkoutmani, Davor Lučić, Maria Grazia Mazzocchi, Evangelia Michaloudi, Arseniy R. Morov, Tuba Terbıyık Kurt, Valentina Tirelli, Jessica Vannini, Ximena Velasquez, Olja Vidjak and Marianne Wootton Show full author list Hide full author list

J. Mar. Sci. Eng. 2023, 11(6), 1238; https://doi.org/10.3390/jmse11061238 - 16 Jun 2023

Cited by 2 | Viewed by 1943

Abstract

Among non-native copepods, the calanoid Pseudodiaptomus marinus Sato, 1913 is the species probably spreading at the fastest pace in European and neighbouring waters since its first record in the Adriatic Sea in 2007. In this contribution, we provide an update on the distribution [...] Read more.

Among non-native copepods, the calanoid Pseudodiaptomus marinus Sato, 1913 is the species probably spreading at the fastest pace in European and neighbouring waters since its first record in the Adriatic Sea in 2007. In this contribution, we provide an update on the distribution of P. marinus in the Mediterranean and Black Seas, along the Atlantic coasts of Europe, in the English Channel and in the southern North Sea. Starting from a previous distribution overview, we include here original and recently (2019–2023) published data to show the novel introduction of this species in different geographical areas, and its secondary spreading in already colonised regions. The picture drawn in this work confirms the strong ability of P. marinus to settle in environments characterised by extremely diverse abiotic conditions, and to take advantage of different vectors of introduction. The data presented allow speculations on realistic future introductions of P. marinus and on the potential extension of its distribution range. Full article

(This article belongs to the Special Issue Ecology of Marine Zooplankton)

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15 pages, 2424 KiB

Open AccessArticle

Analytical and Computational Modeling for Multi-Degree of Freedom Systems: Estimating the Likelihood of an FOWT Structural Failure

by Oleg Gaidai, Jingxiang Xu, Vladimir Yakimov and Fang Wang

J. Mar. Sci. Eng. 2023, 11(6), 1237; https://doi.org/10.3390/jmse11061237 - 16 Jun 2023

Cited by 18 | Viewed by 1200

Abstract

Wind turbines and their associated parts are subjected to cyclical loads, such as bending, torque, longitudinal stresses, and twisting moments. The novel spatiotemporal reliability technique described in this research is especially useful for high-dimensional structural systems that are either measured or numerically simulated [...] Read more.

Wind turbines and their associated parts are subjected to cyclical loads, such as bending, torque, longitudinal stresses, and twisting moments. The novel spatiotemporal reliability technique described in this research is especially useful for high-dimensional structural systems that are either measured or numerically simulated during representative observational time span. As this study demonstrates, it is possible to predict risks of dynamic system failure or damage given the in situ environmental load pattern. As an engineering example for this reliability, the authors have chosen 10-MW floating wind turbines and their dynamic responses, under environmental loadings, caused by wind and waves. The aim of this study was to benchmark a state-of-the-art approach suitable for the reliable study of offshore wind turbines. Existing reliability methods do not easily cope with dynamic system high dimensionality. The advocated reliability technique enables accurate and efficient assessment of dynamic system failure probability, accounting for system nonlinearities and high dimensionality as well as cross-correlations between different system components. Full article

(This article belongs to the Special Issue Failure Analysis of Marine Structure II)

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27 pages, 17576 KiB

Open AccessArticle

Path Following of an Underwater Snake-like Robot Exposed to Ocean Currents and Locomotion Efficiency Optimization Based on Multi-Strategy Improved Sparrow Search Algorithm

by Jing Liu, Haitao Zhu, Yan Chen and Han Bao

J. Mar. Sci. Eng. 2023, 11(6), 1236; https://doi.org/10.3390/jmse11061236 - 16 Jun 2023

Viewed by 1083

Abstract

In this paper, we propose a cubic spline interpolation method to generate a desired curve path and present an integral line of sight (ILOS) method and a control strategy for course tracking control based on nonsingular terminal sliding mode to enable an underwater [...] Read more.

In this paper, we propose a cubic spline interpolation method to generate a desired curve path and present an integral line of sight (ILOS) method and a control strategy for course tracking control based on nonsingular terminal sliding mode to enable an underwater snake-like robot (USR) to move towards and follow the path generated by the parametric cubic-spline interpolation (PCSI) path-planning method, while considering the disturbances caused by ocean currents. The efficiency of robot locomotion is an important evaluation criterion for robot design. Thus, we introduce a multi-strategy improved sparrow search algorithm (MISSA) to dynamically choose gait parameters that significantly enhance the efficiency of robot movement. We conduct simulations to demonstrate that the proposed controller enables the USR, subjected to ocean currents, to accurately converge towards and follow the target path. Our results also reveal that MISSA effectively enhances the locomotion efficiency of the robot. Full article

(This article belongs to the Section Ocean Engineering)

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21 pages, 3638 KiB

Open AccessArticle

Safety-Guaranteed, Robust, Nonlinear, Path-Following Control of the Underactuated Hovercraft Based on FTESO

by Mingyu Fu and Qiusu Wang

J. Mar. Sci. Eng. 2023, 11(6), 1235; https://doi.org/10.3390/jmse11061235 - 15 Jun 2023

Cited by 2 | Viewed by 1169

Abstract

On account of the external disturbances and difficult maneuverability of a hovercraft, this paper devises a safety-guaranteed, robust, nonlinear, path-following control strategy of a hovercraft targeted for unknown dynamics, unavailable velocity, and unknown external ocean disturbances. Firstly, for the sake of accurately observing [...] Read more.

On account of the external disturbances and difficult maneuverability of a hovercraft, this paper devises a safety-guaranteed, robust, nonlinear, path-following control strategy of a hovercraft targeted for unknown dynamics, unavailable velocity, and unknown external ocean disturbances. Firstly, for the sake of accurately observing unavailable lumped disturbances and unavailable velocity measurements, a finite-time extended state observer (FTESO) is proposed. Secondly, a line-of-sight (LOS) guidance law constructed with a bounded-gain-forgetting (BGF) adaptive estimator is devised to follow the desired path while considering external environmental disturbances accurately, in which the tracking errors and the parameter estimation are both proven to be bounded. In addition, for the sake of safety, a safety-guaranteed auxiliary system that can constrain the drift angle during the hovercraft’s navigation is proposed. Thirdly, the robust, nonlinear, path-following controllers achieved high tracking performance with the constructed safety-guaranteed compensation backstepping method. Finally, according to the Lyapunov and homogeneous theories, the observation error can be guaranteed to zero and the tracking error can converge to an arbitrarily small region near zero in finite time. Numerical simulations illustrate the effectiveness for the proposed robust, nonlinear, path-following scheme. Full article

(This article belongs to the Section Ocean Engineering)

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29 pages, 6113 KiB

Open AccessArticle

Enhancing Container Vessel Arrival Time Prediction through Past Voyage Route Modeling: A Case Study of Busan New Port

by Jeong-Hyun Yoon, Dong-Ham Kim, Sang-Woong Yun, Hye-Jin Kim and Sewon Kim

J. Mar. Sci. Eng. 2023, 11(6), 1234; https://doi.org/10.3390/jmse11061234 - 15 Jun 2023

Cited by 5 | Viewed by 2071

Abstract

Container terminals are at the center of global logistics, and are highly dependent on the schedule of vessels arriving. Conventional ETA records from ships, utilized for terminal berth planning, lack sufficient accuracy for effective plan implementation. Thus, there is a pressing need for [...] Read more.

Container terminals are at the center of global logistics, and are highly dependent on the schedule of vessels arriving. Conventional ETA records from ships, utilized for terminal berth planning, lack sufficient accuracy for effective plan implementation. Thus, there is a pressing need for improved ETA prediction methods. In this research, we propose a novel approach that leverages past voyage route patterns to predict the ETA of container vessels arriving at a container terminal at Busan New Port, South Korea. By modeling representative paths based on previous ports of call, the method employs real-time position and speed data from the Automatic Identification System (AIS) to predict vessel arrival times. By inputting AIS data into segmented representative routes, optimal parameters yielding minimal ETA errors for each vessel are determined. The algorithm’s performance evaluation during the modeling period demonstrates its effectiveness, achieving an average Mean Absolute Error (MAE) of approximately 3 h and 14 min. These results surpass the accuracy of existing ETA data, such as ETA in the Terminal Operating System and ETA in the AIS of a vessel, indicating the algorithm’s superiority in ETA estimation. Furthermore, the algorithm consistently outperforms the existing ETA benchmarks during the evaluation period, confirming its enhanced accuracy. Full article

(This article belongs to the Special Issue Data Analytics in Maritime Research)

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19 pages, 2879 KiB

Open AccessArticle

Estimate of Cetacean and Shark Depredations in the Small-Scale Longline Fishery in the Southeastern Waters of Taiwan

by Kwang-Ming Liu, Kuan-Yu Su and Chien-Pang Chin

J. Mar. Sci. Eng. 2023, 11(6), 1233; https://doi.org/10.3390/jmse11061233 - 15 Jun 2023

Viewed by 1082

Abstract

Cetacean and shark depredations in a small-scale longline fishery in the southeastern Taiwan waters were estimated based on interviews of 21 fishermen and logbooks of 12 sampling vessels, including 649 operations (681,310 hooks) from October 2009 to December 2010. Cetacean depredations were more [...] Read more.

Cetacean and shark depredations in a small-scale longline fishery in the southeastern Taiwan waters were estimated based on interviews of 21 fishermen and logbooks of 12 sampling vessels, including 649 operations (681,310 hooks) from October 2009 to December 2010. Cetacean depredations were more serious than shark depredations, with damage rates of 19.26% and 11.56%, respectively. The depredation rates in number and weight from cetaceans were estimated to be 2.21% and 3.23%, respectively, and were significantly higher than those from sharks, which were estimated to be 0.51% and 0.47%, respectively. The depredation indices from cetacean and shark were estimated to be 0.93 and 0.22 per 1000 hooks, respectively. The dolphinfish and yellowfin tuna were the top two species depredated by cetaceans and sharks. The annual economic loss of the small-scale longline fishery due to cetacean and shark depredations was estimated to be USD 441.9 thousand and USD 58.8 thousand, respectively, which corresponded to 4.5% and 0.6% of the total sales of the longline fishery at Hsinkang fishing port, southeastern Taiwan. The catch in number of dolphinfish and the operation depth were significant factors that affected cetacean depredations. Full article

(This article belongs to the Topic Conservation and Management of Marine Ecosystems)

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29 pages, 1162 KiB

Open AccessReview

Global Changes Alter the Successions of Early Colonizers of Benthic Surfaces

by Emanuele Somma, Antonio Terlizzi, Maria Costantini, Madalena Madeira and Valerio Zupo

J. Mar. Sci. Eng. 2023, 11(6), 1232; https://doi.org/10.3390/jmse11061232 - 15 Jun 2023

Cited by 2 | Viewed by 1773

Abstract

The successions of benthic communities over time are strongly influenced by the first colonizers, because surface associations are facilitated by modifications to the adhesive properties promoted by primary colonizers, such as bacteria, protozoans, diatoms, algal propagules, spores, and invertebrate larvae. Bacteria are often [...] Read more.

The successions of benthic communities over time are strongly influenced by the first colonizers, because surface associations are facilitated by modifications to the adhesive properties promoted by primary colonizers, such as bacteria, protozoans, diatoms, algal propagules, spores, and invertebrate larvae. Bacteria are often the first colonizers on marine submerged surfaces, both organic (e.g., algae, seagrasses and invertebrates) and inorganic. However, they are promptly followed by diatoms and other microorganisms. Consequently, diatoms may represent key elements in the determination of the colonization patterns, although the development of epiphytic communities is a dynamic process influenced by several factors, including nutrient availability, the ability to synthesize and secrete extracellular material, the competition among species and the influence of grazers on individual colonizers. The process may be drastically impacted by global warming and ocean acidification due to the increasing atmospheric levels of CO₂. The impact of such global stressors on benthic ecosystems, especially on the primary microphytobenthic assemblages, is still poorly investigated, and may have deleterious consequences for the benthic successions. In this review, we analyze the adhesion patterns of marine microorganisms according to their surface features and the effects of global changes on critical pioneer colonizers, such as the benthic diatoms. The results are remarkable, as they highlight emergent concerns in ecosystem conservation and the prediction of benthic communities. Full article

(This article belongs to the Special Issue Feature Papers in Marine Biology)

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28 pages, 8353 KiB

Open AccessArticle

Fuel Consumption Prediction and Optimization Model for Pure Car/Truck Transport Ships

by Miao Su, Zhenqing Su, Shengli Cao, Keun-Sik Park and Sung-Hoon Bae

J. Mar. Sci. Eng. 2023, 11(6), 1231; https://doi.org/10.3390/jmse11061231 - 15 Jun 2023

Cited by 3 | Viewed by 2203

Abstract

Predicting and optimizing ship fuel use is a crucial technology for lowering greenhouse gas emissions. Unfortunately, existing research is rarely capable of developing fuel consumption forecasts and optimization models for a particular transport system. This study develops a fuel consumption prediction model based [...] Read more.

Predicting and optimizing ship fuel use is a crucial technology for lowering greenhouse gas emissions. Unfortunately, existing research is rarely capable of developing fuel consumption forecasts and optimization models for a particular transport system. This study develops a fuel consumption prediction model based on machine learning and a fuel consumption optimization model based on particle swarm optimization for ships. We studied nearly ten years of big data from a large Korean pure car and truck shipping company (PCTC), which contained 16,189 observations from 2012 to 2021. Results indicate that the XGBoost deep learning model outperforms conventional prediction models at the stage of fuel consumption prediction, with an R² of 0.97. Furthermore, in the fuel consumption optimization stage, the particle swarm optimization method can effectively reduce fuel consumption. This study helps PCTC companies control shipping costs and save energy. Insights for shipping businesses to meet environmental demands are provided as well. Full article

(This article belongs to the Special Issue Safety and Efficiency of Maritime Transportation and Ship Operations)

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28 pages, 59211 KiB

Open AccessArticle

Sedimentological, Diagenetic, and Sequence Stratigraphic Controls on the Shallow to Marginal Marine Carbonates of the Middle Jurassic Samana Suk Formation, North Pakistan

by Shazia Qamar, Mumtaz Muhammad Shah, Hammad Tariq Janjuhah, George Kontakiotis, Amir Shahzad and Evangelia Besiou

J. Mar. Sci. Eng. 2023, 11(6), 1230; https://doi.org/10.3390/jmse11061230 - 15 Jun 2023

Cited by 2 | Viewed by 1763

Abstract

This study presents a thorough analysis of the sedimentology, diagenesis, and sequence stratigraphy of the Middle Jurassic Samana Suk Formation in the Hazara Basin of northern Pakistan. Focusing on two sections, namely Mera Rehmat and Por Miana, the research aims to unravel the [...] Read more.

This study presents a thorough analysis of the sedimentology, diagenesis, and sequence stratigraphy of the Middle Jurassic Samana Suk Formation in the Hazara Basin of northern Pakistan. Focusing on two sections, namely Mera Rehmat and Por Miana, the research aims to unravel the complex geological processes within the formation. The examination of microfacies reveals nine distinct depositional textures, ranging from mudstone to wackestone, packstone, and grainstone, indicating various inner ramp environments such as open marine, lagoon, and coastal settings. Petrographic investigations shed light on diagenetic processes, including micritization, cementation, dissolution, compaction, neomorphism, and dolomitization. Six cementation types are identified, and the dolomitization patterns vary, providing insights into lagoonal environments and mudstone replacement. Sequence stratigraphic analysis uncovers intriguing patterns within the Samana Suk Formation. The high-stand system tract is characterized by mudstones, pelloidal grainstones, and dolomitized mudstones, indicating periods of high sea level. In contrast, the transgressive system tract displays ooidal grainstones, pelloidal packstones, and pel-bioclastic grainstones, representing transgression and inundation of previously exposed areas. A significant finding is the impact of diagenesis on reservoir quality parameters, specifically porosity, and permeability. Diagenetic processes, cementation types, and dolomitization patterns have significantly altered the pore network, highlighting the importance of considering diagenesis in assessing the Samana Suk Formation as a hydrocarbon reservoir. This research provides a comprehensive understanding of the sedimentology, diagenesis, and sequence stratigraphy of the Middle Jurassic Samana Suk Formation. The findings contribute to our knowledge of similar carbonate reservoirs globally, enhancing the exploration and development of hydrocarbon resources in comparable depositional environments. Full article

(This article belongs to the Special Issue Recent Advances in Geological Oceanography II)

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2 pages, 875 KiB

Open AccessCorrection

Correction: Capasso et al. Regular Wave Seakeeping Analysis of a Planing Hull by Smoothed Particle Hydrodynamics: A Comprehensive Validation. J. Mar. Sci. Eng. 2023, 11, 700

by Salvatore Capasso, Bonaventura Tagliafierro, Simone Mancini, Iván Martínez-Estévez, Corrado Altomare, José M. Domínguez and Giacomo Viccione

J. Mar. Sci. Eng. 2023, 11(6), 1229; https://doi.org/10.3390/jmse11061229 - 15 Jun 2023

Viewed by 584

Abstract

In the original publication [...] Full article

(This article belongs to the Special Issue Seakeeping and Performance in Waves of Marine Vessels)

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20 pages, 3016 KiB

Open AccessArticle

Evolutionary Palaeoecological and Morphological Response of Globorotalia menardii to Environmental Stress Conditions Preceding the Tortonian–Messinian Boundary in the Mediterranean Basin

by Evangelia Besiou, George Kontakiotis, Iuliana Vasiliev, Pierre Moissette, Jean-Jacques Cornée and Assimina Antonarakou

J. Mar. Sci. Eng. 2023, 11(6), 1228; https://doi.org/10.3390/jmse11061228 - 15 Jun 2023

Viewed by 1146

Abstract

The Tortonian–Messinian transition is associated with important climatic and oceanographic changes in the Mediterranean Basin, which have shaped both the biotic and abiotic nature of this setting. The morphological variability of the planktonic foraminifera Globorotalia menardii, a species that is highly sensitive [...] Read more.

The Tortonian–Messinian transition is associated with important climatic and oceanographic changes in the Mediterranean Basin, which have shaped both the biotic and abiotic nature of this setting. The morphological variability of the planktonic foraminifera Globorotalia menardii, a species that is highly sensitive to water column structure, has been investigated from the sedimentary archive of three Cretan sections across a west–east transect covering the Tortonian–Messinian Boundary. The present work explicitly focuses on test-size and coiling direction changes occurring during the 7.36–7.24 Ma time slice. On such a short timescale, the most important morphological differentiation accounts for the average size of G. menardii, which is mostly associated with evolutionary adaptation to new ecological niches during the latest Tortonian as a response to the environmental perturbations and ecological stress conditions preceding the Tortonian–Messinian Boundary. A combined thermal and/or salinity-driven stratification and thermocline development hypothesis has been suggested to explain the observed size variability. To ameliorate the accuracy of the proposed model and further determine which environmental parameter reflects the optimum conditions of the analysed species, additional sea surface temperature and salinity data derived from the same sampling intervals of the studied or additional Mediterranean sites are needed. The coiling direction of this species within the study time interval remained constant and not environmentally controlled. Full article

(This article belongs to the Special Issue Advances in Marine Micropaleontology)

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13 pages, 3709 KiB

Open AccessArticle

Wind Drift, Breakdown, and Pile Up of the Ice Field

by Vadim K. Goncharov

J. Mar. Sci. Eng. 2023, 11(6), 1227; https://doi.org/10.3390/jmse11061227 - 14 Jun 2023

Viewed by 1000

Abstract

This article contains the analytical model of the drift of a separate ice field under the action of wind and current, in which velocities and directions can vary over time. The model takes into account the mass of ice, added mass of seawater, [...] Read more.

This article contains the analytical model of the drift of a separate ice field under the action of wind and current, in which velocities and directions can vary over time. The model takes into account the mass of ice, added mass of seawater, and the effects of the wind and current on the ice field in forming the friction on its upper and underwater surfaces and the frontal resistance on its end (forward and backward) surfaces. Simulation of the wind drift of the ice field showed the drift velocity exceeds the considerable known velocity of a compact ice cover drift. A drifting ice field has a certain kinetic energy that should be released when a collision occurs with an unmovable obstacle, and spent on brittle breakdown of a quantity of the ice field. The volume of formed small ice pieces (fragments of ice field) was estimated by comparison of the specific energy of the sea ice brittle destruction and the kinetic energy of the drifting ice field. The article presents the results of the estimation of the possible volume of the ice pieces and the scales of formed piles as a result of a collision with an obstacle, depending on the initial dimensions of the ice field and wind speed. Developed models and the results of computer modeling can be used to estimate the ice pile sizes near the stationary platforms and terminals on the Arctic seas. Full article

(This article belongs to the Special Issue The Ice-Ocean Boundary)

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23 pages, 6204 KiB

Open AccessArticle

Underwater Color-Cast Image Enhancement by Noise Suppression and Block Effect Elimination

by Yu Ning, Yong-Ping Jin, You-Duo Peng and Jian Yan

J. Mar. Sci. Eng. 2023, 11(6), 1226; https://doi.org/10.3390/jmse11061226 - 14 Jun 2023

Viewed by 1227

Abstract

Efficient underwater visual environment perception is the key to realizing the autonomous operation of underwater robots. Because of the complex and diverse underwater environment, the underwater images not only have different degrees of color cast but also produce a lot of noise. Due [...] Read more.

Efficient underwater visual environment perception is the key to realizing the autonomous operation of underwater robots. Because of the complex and diverse underwater environment, the underwater images not only have different degrees of color cast but also produce a lot of noise. Due to the existence of noise in the underwater image and the blocking effect in the process of enhancing the image, the enhanced underwater image is still rough. Therefore, an underwater color-cast image enhancement method based on noise suppression and block effect elimination is proposed in this paper. Firstly, an automatic white balance algorithm for brightness and color balance is designed to correct the color deviation of underwater images and effectively restore the brightness and color of underwater images. Secondly, aiming at the problem of a large amount of noise in underwater images, a noise suppression algorithm for heat conduction matrix in the wavelet domain is proposed, which suppresses image noise and improves the contrast and edge detail information of underwater images. Thirdly, for the block effect existing in the process of enhancing the underwater color-cast image, a block effect elimination algorithm based on compressed domain boundary average is proposed, which eliminates the block effect in the enhancement process and balances the bright area and dark area in the image. Lastly, multi-scale image fusion is performed on the images after color correction, noise suppression, and block effect elimination, and finally, the underwater enhanced image with rich features is obtained. The results show that the proposed method is superior to other algorithms in color correction, contrast, and visibility. It also shows that the proposed method corrects the underwater color-cast image to a certain extent and effectively suppresses the noise and block effect of the underwater image, which provides theoretical support for underwater visual environment perception technology. Full article

(This article belongs to the Section Physical Oceanography)

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