Applied Ocean Research最新文献_第6页

Semi-supervised learning network for deep-sea nodule mineral image segmentation

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104356

Zhongjun Ding , Chen Liu , Xingyu Wang , Guangyang Ma , Chanjuan Cao , Dewei Li

{"title":"Semi-supervised learning network for deep-sea nodule mineral image segmentation","authors":"Zhongjun Ding , Chen Liu , Xingyu Wang , Guangyang Ma , Chanjuan Cao , Dewei Li","doi":"10.1016/j.apor.2024.104356","DOIUrl":"10.1016/j.apor.2024.104356","url":null,"abstract":"<div><div>The accurate segmentation of deep-sea nodule mineral images is crucial for scientific mining. However, due to the low contrast of deep-sea images and the varying sizes of nodule minerals, existing methods are not effective in segmenting these images. Furthermore, fully supervised deep learning methods require numerous labelled images for training, and labelling deep-sea nodule mineral images is highly difficult, resulting in a scarcity of available labeled images, which limits the model generalization ability. To address these challenges, a semi-supervised learning network for deep-sea nodule image segmentation (NmiNet) was proposed. In this method, a semi-supervised training paradigm based on underwater image enhancement perturbation and uncertainty weighted optimization (UEUO) was designed. This paradigm enabled the model to fully mine the features in many unlabeled nodule mineral images under the condition of few labelled nodule mineral images, improving the model generalization ability. Moreover, a lightweight global and local feature extraction (GLFE) module was designed to enhance the attention of the module to small nodules, and its ability to locate nodules of different scales by fusing local and global features without considerably increasing model complexity. Experimental results on deep-sea nodule mineral images reveal that this method outperforms existing approaches.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104356"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Polyester line damage assessment considering fatigue and abrasion

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104376

Hongsheng Yan, Tongyu Jia, Jianxing Yu

引用次数: 0

Nonlinear modeling of the 3-D ocean sound speed field via incremental sample convolutional exchange network

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104383

Kequan Shi , Qi Li , Pan Xu , Bingbing Zhang , Hongna Zhu

{"title":"Nonlinear modeling of the 3-D ocean sound speed field via incremental sample convolutional exchange network","authors":"Kequan Shi , Qi Li , Pan Xu , Bingbing Zhang , Hongna Zhu","doi":"10.1016/j.apor.2024.104383","DOIUrl":"10.1016/j.apor.2024.104383","url":null,"abstract":"<div><div>The accurate construction of the underwater sound speed fields (SSFs) is critical for systems of positioning, navigation, timing, and communication (PNTC). Currently, the 3-D ocean currents observation is limited by insufficient flow field data and technical constraints, resulting in significant sound speed errors that adversely affect underwater positioning accuracy. To address the challenge of achieving continuous spatiotemporal observations within marine areas, we propose an incremental sample convolutional exchange network (ISCEN) to construct localized 3-D ocean SSFs. Through split and interactive learning, the model iteratively extracts and exchanges ocean acoustic environmental parameters across multiple temporal resolutions. Therefore, it can learn enhanced features of the SSFs and predicting future sound speed distributions. Note that the limitations of computational power and prolonged training times associated with traditional offline learning, we introduce an improved incremental learning method. This approach leverages prior information to achieve intelligent and high-precision construction of SSFs. Experimental results indicate that the model can accurately reconstruct sound speed profiles (SSPs) within the 0 m to 2000 m depth range in selected regions of the South China Sea and the Western Pacific on CORTA 1.0-WNP dataset. The proposed method can flexibly provide real-time sound speed distributions tailored to the varying needs across different areas.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104383"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sediment dynamics and vegetation resilience: A case study on the tidal flats in the Yangtze Delta

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104399

Yong Xu , Haifei Yang , Hongjie Qiao , Chunye Hu , Biaobiao Peng , Zhenchang Zhu , Ya Ping Wang

{"title":"Sediment dynamics and vegetation resilience: A case study on the tidal flats in the Yangtze Delta","authors":"Yong Xu , Haifei Yang , Hongjie Qiao , Chunye Hu , Biaobiao Peng , Zhenchang Zhu , Ya Ping Wang","doi":"10.1016/j.apor.2024.104399","DOIUrl":"10.1016/j.apor.2024.104399","url":null,"abstract":"<div><div>Salt marshes are among the most resilient systems in coastal environments, playing a key role in resisting rising sea level through sediment accretion and mitigating the pressures of climate change. However, our understanding of the highly complex interactions between salt marsh vegetation resilience and sediment dynamics is limited. Hence this study collected data from three land-to-sea stations (interior salt marsh, salt marsh edge, mudflat) in the Yangtze Delta. Our findings revealed that waves were attenuated more heavily than currents in salt marshes, whereas both dissipated less intensely in mudflats. The tide-averaged, wave-current coupled bed shear stress was 0.25 N/m<sup>2</sup> at the mudflat, respectively 1.5 and 2.2 times greater than values at the edge of the salt marsh (0.17 N/m<sup>2</sup>) and in the marsh itself (0.12 N/m<sup>2</sup>). The dynamic intensity (bed-shear-stress impulse after accounting for inundation duration), was 2.1 and 3.2 times higher at the mudflat than at the other two stations. We identified two possible key interactive processes. First, long-term dynamic intensity could be a better representative indicator that affects the spatial distribution of vegetation, with plants becoming sparser seaward as the enhancement of dynamic intensity accelerates. Second, root length might be related to intratidal-scale sediment resuspension controlled by hydrodynamic forces, with roots becoming shorter shoreward as the thickness of intratidal erodible sediment decreases. In conclusion, we addressed the critical question of how environmental drivers affect spatial distribution and resilience of salt marsh vegetation. These findings have major implications for global efforts to restore natural coastal ecosystems and enhance resilience against marine disasters.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104399"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Stability analysis of high-speed spin-stabilized supercavitating projectiles during water entry

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104379

Changle Hao, Jianjun Dang, Chuang Huang, Kai Luo, Kan Qin

{"title":"Stability analysis of high-speed spin-stabilized supercavitating projectiles during water entry","authors":"Changle Hao, Jianjun Dang, Chuang Huang, Kai Luo, Kan Qin","doi":"10.1016/j.apor.2024.104379","DOIUrl":"10.1016/j.apor.2024.104379","url":null,"abstract":"<div><div>This study explores the fluid-structure interaction (FSI) phenomena associated with spin-stabilized supercavitating projectiles and the influence on the structural stability of the projectiles. Fluid-structure interaction simulations are performed on projectiles during high-speed water entry, and the results are contrasted with those derived from rigid body models. The results highlight that rigid body simulations are unreliable at high spin rates, showing considerable inaccuracies. Both FSI and theoretical analyses identify a critical spin angular velocity above which significant structural deformation occurs, compromising stability. Theoretical analysis has identified an optimal spin angular velocity, calculated as the critical velocity multiplied by 1/√2, which minimizes bending deformation. The findings from this study are critically important for the design of spin-stabilized supercavitating projectiles, suggesting the use of the natural frequency of the projectile to estimate critical spin angular velocity and thereby guide design strategies to enhance structural stability. This approach offers a practical strategy to avoid excessive deformation and optimize the projectile's trajectory stability during high-speed water entry.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104379"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A comparison of machine learning classifiers in predicting safety for a multi-component dynamic system representation of an autonomous vessel

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104368

Brendan Sulkowski, Matthew Collette

{"title":"A comparison of machine learning classifiers in predicting safety for a multi-component dynamic system representation of an autonomous vessel","authors":"Brendan Sulkowski, Matthew Collette","doi":"10.1016/j.apor.2024.104368","DOIUrl":"10.1016/j.apor.2024.104368","url":null,"abstract":"<div><div>To operate autonomously for weeks to months at a time, crewless vessels must be able to integrate uncertain estimates of sub-system health and weather forecasts into operational plans. To date, most digital twins have focused on estimating the health of single sub-systems, not the multi-system integration problem. This work establishes a four-component integration problem using real-world weather forecasts from the European Centre for Medium-Range Weather Forecast and a simulated linear spring–mass–damper system excited by wave elevation. Each component in the spring–mass–damper system is monitored with techniques of differing accuracies representative of marine-type health uncertainties. Weather forecast uncertainty is included using weather predictions of significant wave height and peak period up to 10 days out. As well as their exact values, different test cases include the spring, mass, and damper being modeled as noisy sensors representative of sensors onboard a vessel, as well as the spring being modeled as a visually-inspected system component, reflective of human impact onboard a vessel. The performance of five established machine learning classification algorithms, Support Vector Machines, K Nearest Neighbors, Decision Trees, Random Forest, and XGBoost in assessing if the spring–mass–damper system will exceed a displacement threshold is then evaluated for 1000 physical locations under the differing uncertainty assumptions. Overall, even for the simple linear system considered here, none of the existing methods perform with high accuracy when subject to common types of uncertainty, with the SVM system generally performing best and the DT system performing worse. Conclusions and discussions for improving system-level synthesis are made.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104368"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evacuation simulation in inclined ship environment based on improved social force model

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2025.104415

Miao Chen , Xinwei Li , Duanfeng Han , MIngyang Guo , Jacqueline Lo , Chao Liu

{"title":"Evacuation simulation in inclined ship environment based on improved social force model","authors":"Miao Chen , Xinwei Li , Duanfeng Han , MIngyang Guo , Jacqueline Lo , Chao Liu","doi":"10.1016/j.apor.2025.104415","DOIUrl":"10.1016/j.apor.2025.104415","url":null,"abstract":"<div><div>To evaluate the evacuation capability of pedestrians in an inclined ship environment, this paper establishes an evacuation model that incorporates both the pushing and self-adjustment forces of pedestrians, based on the social force model. The entropy method is applied to determine the coefficient of pedestrian speed attenuation. Considering the presence of panic during evacuation, a pushing effect model is developed. In this model, a Sigmoid function is used to describe the influence of the inclination angle on the intensity of the pushing effects. Pedestrian spacing and movement direction are introduced as criteria for determining the occurrence of pushing effects. A dynamic assessment of the pushing effect during evacuation is conducted, effectively simulating a realistic evacuation process in an inclined ship environment. Through simulation of a single cabin, the pushing effect among pedestrians during the evacuation process was reproduced, and the presence of pushing increased the evacuation time. Compared to related literature, the evacuation time trend in this study is generally similar; however, considering the presence of pushing effects, the evacuation time obtained in this study is relatively longer. Compared to Pathfinder, the model developed in this study can simulate the pushing effect between pedestrians and accurately reflect the behavior dynamics of crowds under ship inclination conditions.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104415"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Pseudo-inviscid theory for transom-stern flow at low Froude numbers

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104332

Lawrence J. Doctors

引用次数: 0

Experimental study of shallow water solitary wave impacts on a bottom-constrained flexible wall

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104377

Jian Yang , Zhaochen Sun , Jiayang Gu , Xiaojian Ma , Shuxiu Liang

{"title":"Experimental study of shallow water solitary wave impacts on a bottom-constrained flexible wall","authors":"Jian Yang , Zhaochen Sun , Jiayang Gu , Xiaojian Ma , Shuxiu Liang","doi":"10.1016/j.apor.2024.104377","DOIUrl":"10.1016/j.apor.2024.104377","url":null,"abstract":"<div><div>This work investigates wave impacts on the flexible wall. An experiment was conducted to investigate shallow water solitary wave impacts on a flexible wall, and the results are presented. During the experiment, the water depth (<em>h</em>) varied between 0.22 and 0.3 m, the ratio of incident wave height and the water depth (<em>H</em>/<em>h</em>) varied between 0.1 and 0.5. The bottom of the flexible wall was constrained while the top end remained free, with the lowest dry natural frequency being 14.2 Hz. The experiment identified various types of wave impacts, including the flip-through impact without aeration, the low-aeration impact, the high-aeration impact, and the broken wave impact. Subsequently, an analysis was conducted to explore the characteristics of impact pressures, slamming phenomena, and structural deflections under these different impact types. Furthermore, we directed our attention to the correlation between wave conditions and structural dynamic response, discovering that a linear fit adequately describes the relationship between the maximum structural displacement and the relative wave height under the current experimental conditions. This study can be beneficial in enhancing our understanding of wave impacts on flexible walls and provides a solid foundation for future work.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104377"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analytical solutions for instantaneous power of heaving-buoy wave energy converters in irregular waves

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104381

Shixuan Liu, Jinwei Sun, Meng Shao, Shuai Cong, Linqiang Zhang, Chongyang Sun, Wei Tao, Yunming Han

{"title":"Analytical solutions for instantaneous power of heaving-buoy wave energy converters in irregular waves","authors":"Shixuan Liu, Jinwei Sun, Meng Shao, Shuai Cong, Linqiang Zhang, Chongyang Sun, Wei Tao, Yunming Han","doi":"10.1016/j.apor.2024.104381","DOIUrl":"10.1016/j.apor.2024.104381","url":null,"abstract":"<div><div>Evaluating instantaneous power output of heaving-buoy wave energy converters (WECs) with power take-off (PTO) damping in irregular waves has commonly been conducted in the time domain by numerically solving the Cummins equation. Not only is the time domain-method computationally time-consuming, but also no explicit closed-form solution has been available. This paper develops a novel and efficient pole-residue approach, operated in the frequency domain, for estimating instantaneous power of heaving-buoy WECs in arbitrary irregular waves. A closed-form solution for the instantaneous power, which is an explicit function of PTO damping coefficient, is derived. The proposed pole-residue approach formulates the system frequency response function in its analytical form, from which “artificial” poles located along the imaginary axis of complex plane are designated. The correctness of the proposed method is verified by using a time-domain method through numerical examples of a heaving-buoy WEC in regular and irregular waves, respectively. The proposed method would be useful for the practical design and optimization of the PTO system for heaving-buoy WECs.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104381"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0