International Journal of Naval Architecture and Ocean Engineering最新文献

{"title":"A U-net based reconstruction of high-fidelity simulation results for flow around a ship hull based on low-fidelity inviscid flow simulation","authors":"Dayeon Kim ,&nbsp;Jeongbeom Seo ,&nbsp;Inwon Lee","doi":"10.1016/j.ijnaoe.2025.100676","DOIUrl":"10.1016/j.ijnaoe.2025.100676","url":null,"abstract":"<div><div>In this study, neural networks are trained to transform inviscid simulation data for flow around a ship hull into data representative of viscous flow simulations. The objective is to provide high-fidelity viscous flow simulation data using machine learning in conjunction with inviscid flow simulation results, which are significantly less time-consuming to generate. This approach has the potential to accelerate high-fidelity flow simulations by a factor of more than 100, enabling simulation-based design for ship hulls with numerous repetitive cases. To create the training dataset, a variety of hull forms are generated from six baseline hull forms using parametric modification function techniques. Inviscid and viscous flow data for each hull are obtained through potential flow analysis and computational fluid dynamics - simulations, respectively. The neural network structure and hyperparameters are subsequently optimized through parametric studies. The trained neural networks are then employed to predict viscous flow simulation data based on inputs comprising inviscid flow data and hull form geometry. The results demonstrate that the neural networks successfully predicted both the pressure distribution around the hull and the free surface elevation. Notably, the ability to predict the free surface elevation is significant, given that inviscid flow simulations inherently lack this capability. Additionally, the neural network's dimensionality reduction feature is utilized to visualize how the flow and hull form data were clustered within the latent space based on baseline hull forms and ship speed.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100676"},"PeriodicalIF":2.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144702179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scheduling optimization of hull block assembly line using constraint programming and discrete-event simulation","authors":"Dong Hoon Kwak ,&nbsp;Ki-Young Cho ,&nbsp;Cheolho Ryu ,&nbsp;Jong Hun Woo","doi":"10.1016/j.ijnaoe.2025.100675","DOIUrl":"10.1016/j.ijnaoe.2025.100675","url":null,"abstract":"<div><div>Scheduling of a block assembly line in a shipyard is commonly known as the Permutation Flow-shop Scheduling Problem (PFSP) in Operation Research (OR), which has been extensively studied in various papers since the 1950s. However, existing solutions often involve simplifying real-world problems with certain assumptions, limiting their practical applicability. In recent times, Constraint Programming (CP) has emerged as a strong alternative to exact algorithms and has been successfully applied to various PFSP problems, addressing the limitations of exact algorithms. In light of this, our study proposes a two-step optimization process to overcome these limitations. First, a new PFSP problem, Multi-Objective PFSP with hard due date constraint (MOPFSP-hd) is introduced. The problem is solved with CP algorithm. Next, the feasibility and objective value of the optimized solution is validated using Discrete-Event Simulation (DES). Two industrial cases are conducted to evaluate the performance of our proposed framework. The experimental results from both cases demonstrated a significant improvement in makespan compared to manually planned schedule. Additionally, the solutions derived from our proposed model are reported to be feasible, while the manually planned schedules are often infeasible by not satisfying all the constraints or encountering delays. Finally, the difference between the objectives calculated from CP and DES model is analyzed quantitatively using Critical Path Method (CPM).</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100675"},"PeriodicalIF":3.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144720899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of shaft motor/generator on dynamic behavior of natural gas/diesel dual-fuel engine in ship hybrid propulsion system under various operating conditions","authors":"Rui Wang,&nbsp;Yu Ding,&nbsp;Congbiao Sui,&nbsp;La Xiang","doi":"10.1016/j.ijnaoe.2025.100700","DOIUrl":"10.1016/j.ijnaoe.2025.100700","url":null,"abstract":"<div><div>To reduce shipping emissions, natural gas is a viable alternative fuel for marine engines. However, natural gas (or natural gas/diesel dual-fuel) engines exhibit poor dynamic performance, potentially compromising ship safety in adverse conditions. The hybrid propulsion system, which consists of the main engine and shaft motor/generator (MG), can enhance the operational safety of ocean-going cargo ships. This study integrates a mean - value dual-fuel engine model into a hybrid system for a chemical tanker, analyzing dual-fuel engine's dynamic operating range limited by thermal load, surge, knocking, and misfire. The dynamic behavior of dual-fuel engine assisted by shaft MG in different dynamic operating conditions is also investigated. Results show the shaft MG helps smooth load fluctuations, mitigates thermal load and other adverse effects, and improves engine performance. However, the MG's effectiveness does not scale linearly with power output; it should be controlled to make the load change acceptable for the main engine.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100700"},"PeriodicalIF":3.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145516405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on key technologies of a nuclear-powered icebreaker","authors":"Yong Hwan Yoo ,&nbsp;Han Koo Jeong ,&nbsp;Jihoon Lee ,&nbsp;Young Woo Rhee ,&nbsp;Si Hyung Kim ,&nbsp;Seung Youb Han ,&nbsp;Yeongin Park ,&nbsp;Soo Hyoung Kim ,&nbsp;Yong Hoon Jeong ,&nbsp;Hagtae Kim","doi":"10.1016/j.ijnaoe.2025.100703","DOIUrl":"10.1016/j.ijnaoe.2025.100703","url":null,"abstract":"<div><div>The shipbuilding industry of the Republic of Korea considers nuclear energy as a possible candidate for complying with the IMO (International Maritime Organization) protocol, \"The International Convention for the Prevention of Pollution from Ships,\" improving transportation efficiency, and developing the Northern Sea Route and resources. The Korea Atomic Energy Research Institute (KAERI), Hanwha Ocean, KAIST, and Kunsan National University have collaboratively researched on eight key technologies needed to merge the shipbuilding and nuclear industries into nuclear-powered ships. Through various methods, remarkable results are achieved for eight subtopics. The research focuses on the conceptual design of a nuclear reactor for a class-8 icebreaker, the uni-axial Control Rod Drive Mechanism (CRDM) design, the integrated passive residual heat removal system, high-performance neutron absorbers, and the overall design and arrangement of the icebreaker. Additionally, an analysis is conducted to assess the ship's operational performance and safety against explosions and fire accidents. The research results are expected to provide foundational data for future research and design efforts in nuclear-powered ships.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100703"},"PeriodicalIF":3.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145568261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automated design parameter extraction and restoration from 2D propeller drawings","authors":"Jun-Su Park,&nbsp;Seung-Ho Ham","doi":"10.1016/j.ijnaoe.2025.100689","DOIUrl":"10.1016/j.ijnaoe.2025.100689","url":null,"abstract":"<div><div>The shipbuilding industry increasingly needs 3D propeller models from 2D drawings for repair, retrofitting, and energy-saving device (ESD) analysis. However, clients often provide only 2D drawings due to security, making manual information extraction for propeller models time-consuming, labor-intensive, and prone to errors. This highlights the need for automated, accurate extraction techniques. This study proposes a line detection and information extraction method to obtain design parameters from 2D propeller drawings. The method converts PDF drawings to images, preprocesses them, and then uses a path-finding algorithm to detect lines and extract information. This extracted data is converted into design parameters like rake, skew, chord length, camber, and thickness through offset data acquisition. Applying this method to propeller drawings significantly reduces time and effort compared to manual work, greatly improving efficiency and restoration accuracy. The method effectively detects complex and overlapping lines, and the quantitative accuracy of the extracted design parameters has been validated, with most parameters showing less than 1 % error.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100689"},"PeriodicalIF":3.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145026763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of object detection accuracy based on the density of 3D point clouds for deep learning-based shipyard datasets","authors":"Ki-Seok Jung ,&nbsp;Dong-Kun Lee","doi":"10.1016/j.ijnaoe.2025.100648","DOIUrl":"10.1016/j.ijnaoe.2025.100648","url":null,"abstract":"<div><div>3D point clouds are a crucial data format for accurately capturing geometric information in large-scale industrial environments such as shipyards. Deep learning-based object detection technology using 3D point clouds enables automated production management and process optimization. However, the large volume characteristic of 3D point clouds remains a challenge due to the resources and time required for data processing and dataset construction. The large volume of 3D point clouds leads to excessive computational costs, storage demands, and time consumption during dataset construction and training. Therefore, it is necessary to appropriately reduce the dataset size for efficient utilization while ensuring object detection performance. This necessitates a study on dataset downsampling strategies that maintain optimal density and detection accuracy. In this study, an experimental dataset similar to the S3DIS (Stanford Large-Scale 3D Indoor Spaces) dataset was constructed. The density of the 3D point clouds was adjusted in five levels by reducing points per unit area by 20% increments. These datasets were applied to a deep learning architecture to analyze object detection accuracy. Subsequently, the findings were applied to a shipyard dataset to streamline large volume point clouds and evaluate detection performance, thereby assessing their practical applicability. The results demonstrated that reducing the experimental dataset density to approximately 20% still maintained object detection accuracy of around 95% IoU for key objects. This indicates that lightweight datasets can reduce processing resources and costs while preserving detection performance. Additionally, applying the approach to real shipyard datasets revealed that object detection was feasible with reduced data (approximately 4.6% of the raw data). This study provides a practical framework for constructing efficient deep learning models for object detection by downsampling datasets in large-scale industrial environments like shipyards. It is expected to contribute to the establishment of automated data management systems for production management and process efficiency enhancement. Further analysis is required to evaluate performance at extreme low densities (below 20%). Moreover, while this study employed simple downsampling techniques, future work should explore the performance of various downsampling methods to optimize detection accuracy.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100648"},"PeriodicalIF":2.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"E2E neural predictive control for vessel: Autonomous berthing via DRL and PIM-MPC","authors":"Yong Xiong,&nbsp;Yuliang Sun","doi":"10.1016/j.ijnaoe.2025.100692","DOIUrl":"10.1016/j.ijnaoe.2025.100692","url":null,"abstract":"<div><div>In complex marine environments, vessel berthing operations face challenges including nonlinear dynamic effects, strong coupling issues, environmental uncertainties, underactuated characteristics, and multiple constraints. This study proposes a fully data-driven end-to-end vessel berthing control strategy based on Deep Reinforcement Learning (DRL). The study trained a Long Short-Term Memory (LSTM) neural network predictive model using historical vessel input–output data and designed a Model Predictive Controller (MPC) to achieve precise berthing operations. Furthermore, the study introduced a Random Forest model to enhance berthing accuracy and reduce control input fluctuations. To further improve berthing safety and real-time performance, the study developed a Refined Integration Method (RIM), proposing the PIM-MPC approach to optimize berthing maneuvers, with comparative analysis against the Random Forest model. Simulation results confirm the proposed method achieves high-precision berthing under complex environmental disturbances without requiring accurate vessel dynamics models. This approach enhances real-time performance and significantly reduces control input fluctuations compared to Random Forest methods, while simultaneously improving berthing safety despite requiring no prior berthing control input data. This method demonstrated its capability to achieve highly precise berthing of large vessels within confined port environments. Comprehensive full-scale vessel experiments rigorously validated its feasibility and effectiveness.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100692"},"PeriodicalIF":3.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probabilistic design optimization of shipboard radar mast by adopting RBFN meta-model and various reliability methods","authors":"ChangYong Song","doi":"10.1016/j.ijnaoe.2025.100667","DOIUrl":"10.1016/j.ijnaoe.2025.100667","url":null,"abstract":"<div><div>This study presents a probabilistic design optimization method for enhancing the design safety of shipboard radar mast, which accommodates navigational communication equipment such as radar scanners and antennas. Such structure requires not only robust vibration and strength performance but also minimized weight to reduce marine pollution and increase operational efficiency. Given the lack of definitive classification rules for radar mast structural design, this study employs various reliability analysis methods. A radial basis function neural-network (RBFN) meta-model, generated from Design of Experiments data, was utilized for optimization and reliability analyzes. The probabilistic design optimization problem was formulated to determine the random design variables such that the weight is minimized subject to the probabilistic constraints of vibration and structural strength performance. Various reliability analysis methods such as adaptive importance sampling, first-order reliability method, mean value first-order second moment method, and second-order reliability method were compared to identify the best approach for the probabilistic design optimization. The study concludes by identifying the reliable probabilistic optimal method for improving design safety relative to deterministic design optimization results.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100667"},"PeriodicalIF":2.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144253537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fixed-time dynamic threshold event-triggered anti-windup collaborative control for multi-tug towing of unactuated offshore floating platform","authors":"Yulong Tuo ,&nbsp;Lebin Kong ,&nbsp;Shaolong Geng ,&nbsp;Zhouhua Peng ,&nbsp;Shasha Wang","doi":"10.1016/j.ijnaoe.2025.100706","DOIUrl":"10.1016/j.ijnaoe.2025.100706","url":null,"abstract":"<div><div>This paper proposes a fixed-time event-triggered anti-windup collaborative controller for a towing system consisting of an unactuated offshore platform and multiple tugs. Firstly, a fixed-time virtual controller is proposed to acquire required towing force for the platform to track expected trajectory. Subsequently, the required towing force is allocated as desired towline tensions by quadratic programming algorithm, and corresponding desired length of each towline is calculated through towline catenary model. Based on desired towline tensions and lengths, a fixed-time collaborative controller is constructed for tugs with following key components: the input saturation of tugs is approximated by a Gaussian error function; a fixed-time extended state observer is employed to rapidly estimate compound disturbances including saturation approximation errors; a novel dynamic threshold event-triggered mechanism is designed to decrease the control input update frequency while maintaining the convergence performance of entire control system. Finally, simulation results demonstrate the effectiveness of proposed control method.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100706"},"PeriodicalIF":3.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploration of safe navigation zones for large cruise ships entering Keelung port by fast time simulations","authors":"Sin-Der Lee ,&nbsp;Cheng-Yu Fan ,&nbsp;Chun-Hsin Yang","doi":"10.1016/j.ijnaoe.2025.100690","DOIUrl":"10.1016/j.ijnaoe.2025.100690","url":null,"abstract":"<div><div>Since 2012, Keelung Port has shifted from cargo operations to a tourism-focused harbor. By 2018, it hosted 282 cruise ships and over 940,000 passengers. However, seasonal weather-typhoons in summer and monsoons in winter-poses navigation risks. This study focuses on the SuperStar Aquarius, the most frequent cruise ship at the port in 2018, analyzing its routes using AIS data. Ninety Fast Time Simulations were conducted under six scenarios, mainly under strong northeast monsoon conditions with wind speeds of 8, 10, and 13 m/s and varying tidal flows. Results showed significant route deviations in Zone 2 due to environmental forces. The greatest navigational risk was observed during half-speed entries under winter monsoon conditions, where the combination of reduced maneuverability and strong lateral forces led to excessive drift toward the western breakwater-raising the potential for collisions. The findings provide valuable insights for improving cruise ship navigation safety and guiding port planning efforts.</div></div>","PeriodicalId":14160,"journal":{"name":"International Journal of Naval Architecture and Ocean Engineering","volume":"17 ","pages":"Article 100690"},"PeriodicalIF":3.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145415146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}