en jalali 1 gregorian 1 online 1 fulltext

en This study presents a systematic investigation into the influence of geometric parameters and structural characteristics on the dynamic response of a semi-submersible platform supporting a floating wind turbine, with an emphasis on identifying stable performance regimes rather than determining a single optimal configuration. The analyses initiated with preliminary linear evaluations and were subsequently complemented by nonlinear time-domain simulations. A comparison of these approaches demonstrates that while the linear model is useful for identifying general response trends, it fails to fully capture oscillation amplitudes or the coupling intensity among degrees of freedom, particularly under hydrodynamic nonlinearities and mooring system effects. Consequently, a realistic assessment of system behavior necessitates nonlinear analysis. The investigation focused primarily on surge, heave, and pitch motions, as sway, roll, and yaw contributed minimally to the global response. Results indicate that the vertical and rotational motions of the platform are governed not only by the heave plate geometry but also by its interaction with the offset column arrangement. Variations in heave plate diameter and thickness, in conjunction with the geometric configuration of the offset columns, alter the dynamic response by modifying the added mass, hydrodynamic damping, and the relative positions of the centers of gravity and buoyancy. Within the examined range, heave plate diameters of 24–30 m and thicknesses equivalent to 7–10.5% of the offset column height produced more stable responses without shifting natural frequencies toward resonance. Specifically, a diameter of approximately 28.5 m and a thickness of around 8% yielded balanced surge, heave, and pitch responses. However, comparable performance across adjacent configurations suggests a robust design envelope rather than a single unique optimum. Overall, the findings highlight the utility of evaluating geometric parameters within an integrated framework to elucidate the relationships between platform geometry, hydrodynamic coefficients, and the coupled dynamic response. Floating offshore wind Turbines,Coupled Dynamics,Hull Form Effects,Time-Domain Solution Method,Response Amplitude Operation 1 19 http://ijmt.ir/browse.php?a_code=A-10-246-1&slc_lang=en&sid=1 2026/02/5 1404/11/16 2026/06/8 1405/3/18 Mohammad Javad Eslahi Department of Civil Engineering, SRBIAU mj.eslahi@srbiau.ac.ir 0031947532846004596 0031947532846004596 No saeid kazemi Department of Civil Engineering, SRBIAU Saeid.kazemi@srbiau.ac.ir 0031947532846004597 0031947532846004597 Yes Mojtaba Ezam Department of Physics Oceanography, SRBIAU ezam@srbiau.ac.ir 0031947532846004598 0031947532846004598 No madjid ghodsi hassanabad Department of Mechanical Engineering, SRBIAU m.ghodsi@srbiau.ac.ir 0031947532846004599 0031947532846004599 No

en Stern-tube bearing failures can immobilize vessels and discharge lubricants into the sea, yet traditional threshold-based oil monitoring often overlooks the earliest signs of wear. We have developed an AI-driven predictive-maintenance framework that combines routine oil-analysis data with machine-learning models to detect incipient faults. Using a labelled dataset of 437 samples (54.2 % normal, 40.3 % warning, 5.5 % abnormal), we trained Random Forest and CatBoost classifiers; the Random Forest achieved an overall accuracy of 85 %. Applying the ADASYN over sampler raised recall for the rare abnormal class from 0.42 to 0.73. SHAP analysis identified copper and lead (bearing wear) as well as sodium and boron (seal-water ingress and additive depletion) as the most influential predictors. In a field trial on an AHTS-DP1 vessel, the model flagged rising boron six months before a dry-dock inspection confirmed seal damage caused by fishing-net entanglement, enabling timely repair and averting a potential MARPOL violation. Compared with the operator’s existing rule-based alerts, the proposed system cut false alarms by 40 % while detecting subtle degradation earlier. These findings show that merging tribological expertise with data-driven analytics can markedly enhance stern-tube reliability and promote more sustainable ship operations. Predictive maintenance,Stern tube seals,Oil analysis,Machine learning,SHAP values 20 30 http://ijmt.ir/browse.php?a_code=A-10-8311-1&slc_lang=en&sid=1 2026/02/52025/05/13 1404/2/23 2026/06/82026/07/12 1405/4/21 Mohammad Ali Mohaghegh Faculty of Mechanical Engineering, Sharif University of Technology, Tehran, Iran m.ali.mohaghegh@gmail.com 0031947532846004576 0031947532846004576 No Mehdi Behzad Faculty of Mechanical Engineering, Sharif University of Technology, Tehran, Iran m_behzad@sharif.edu 0031947532846004575 0031947532846004575 Yes Somaye Mohammadi Faculty of Mechanical Engineering, Sharif University of Technology, Tehran, Iran somaye.mohammadi@sharif.edu 0031947532846004574 0031947532846004574 No

en Shahid Beheshti Port stands as a critical maritime infrastructure in Iran, serving as a pivotal transit hub for goods destined for Central Asia. This research aims to elucidate the sedimentation dynamics within Chabahar Bay, both before and following the expansion of the Shahid Beheshti Port. The study employed various modules of the MIKE21 hydrodynamic modeling suite to achieve this objective. The modeling results, comparing pre- and post-development scenarios of Shahid Beheshti Port, reveal that sediments circumnavigate the breakwater before entering the area between the Beheshti breakwater and Kalantari Port. The region north of Kalantari Port, characterized by the rocky Lipar coast and seabed, predominantly experiences erosion, with occasional sedimentation events. The coastal stretch extending from Tis Port to the beach area exhibits a complex interplay of depositional and erosional processes. Erosion rates in this sector are substantial, ranging from approximately 14,000 to 19,600 cubic meters annually. A desalination plant situated along the western coastline acts as a significant sediment trap, with pronounced accumulation on its eastern flank. Conversely, the western side of this structure is subject to erosion due to local current patterns. Sedimentation,Numerical Modeling,Development Plan,Chabahar Bay 31 41 http://ijmt.ir/browse.php?a_code=A-10-923-3&slc_lang=en&sid=1 2026/02/52025/05/132024/10/25 1403/8/4 2026/06/82026/07/122026/07/15 1405/4/24 Shahab Chakarzehi Coastal Engineering Department Chabahar Maritime University, P.O. Box 99717-56499, Chabahar, Iran shahab.chakarzehi@gmail.com 0031947532846004577 0031947532846004577 No Mehdi Rezapour Coastal Engineering Department Chabahar Maritime University, P.O. Box 99717-56499, Chabahar, Iran, E-mail: rezapour@cmu.ac.ir rezapour@cmu.ac.ir 0031947532846004578 0031947532846004578 Yes Seyed Amin Hosseini Mechanical Engineering Department Chabahar Maritime University, P.O. Box 99717-56499, Chabahar, Iran, E-mail: amin.hosseini@cmu.ac.ir amin.hoss@gmail.com 0031947532846004579 0031947532846004579 No Zahra Ranji Metocean Engineer, Van Oord, Rotterdam, Netherland zahra.ranji132@gmail.com 0031947532846004580 0031947532846004580 No

en For maritime shipping companies, stock-return volatility and predictability are not only a finance question but also an indirect signal of the health of the industry’s investment cycle. Improving the accuracy of such forecasts, and quantifying the contribution of individual macroeconomic and commodity factors, therefore matters to both investors and maritime-industry stakeholders, yet remains a challenging task. This paper employs a recursive modelling approach that simulates investor behaviour to test whether macroeconomic and commodity variables help forecast the stock returns of tanker shipping companies. Methods: We follow the recursive approach of Pesaran and Timmermann (2000) and Pourkermani (2023a). A dedicated Matlab routine allows the model structure to change at every step and evaluates the out-of-sample forecasting performance of a set of eight macroeconomic and commodity regressors for five Maritime Company’s companies (Frontline, Knightsbridge Tankers, Nordic American Tankers, and Teekay Corporation) benchmarked against the S&P 500. Results: Contrary to part of the prior literature, we find that permutation-based, information-criterion-selected models do not outperform a fixed model that retains all regressors; the all-variable model consistently delivers the highest net-of-cost return. Conclusion: This paper contributes to the literature by (i) applying the recursive out-of-sample forecasting framework specifically to Maritime Company’s equities, (ii) explicitly accounting for transaction costs when evaluating switching strategies, and (iii) comparing statistical, Akaike, and Bayesian information criteria for model selection in this context. Research Limitation: The model uses historical macroeconomic and commodity data and does not incorporate maritime-specific operational variables such ::as char::ter rates or bunker fuel prices, which we identify as a direction for future research.   Recursive modelling,Maritime Company,Forecast,Simulation 31 43 http://ijmt.ir/browse.php?a_code=A-10-1785-3&slc_lang=en&sid=1 2026/02/52025/05/132024/10/252025/07/19 1404/4/28 2026/06/82026/07/122026/07/152026/08/2 1405/5/11 Kasra Pourkermani Khorramshahr University of Marine Science and Technology pourkermani@kmsu.ac.ir 0031947532846004611 0031947532846004611 Yes

en One of the key features of the next-generation (sixth-generation) military submarines is their capability to carry, launch, and recover AUVs (Autonomous Underwater Vehicles). These AUVs will be responsible for defending the submarine, monitoring and listening to the surrounding environment. This is crucial because, in the future, AUVs are expected to pose the most significant threat to submarines. Heavy and few torpedoes are not effective for dealing with small and numerous AUVs. Therefore, the internal layout of future military submarines should be modified to enable the widespread use of AUVs. The two significant distinctions between AUVs and torpedo launchers are that, firstly, AUVs must be recoverable and not disposable, and secondly, AUVs must be deployed in large numbers simultaneously. As a result, their launchers will be different. In this article, 13 methods are proposed for the deployment of AUVs, and the advantages and disadvantages of each method are also listed. Also, due to the requirement for special launchers for AUVs, the sixth-generation submarines will feature double-hull or combined hull designs, whereas most military submarines in this century have been predominantly single-hull. The article also examines the issue of "ocean transparency," which poses the greatest threat to future submarines.   AUV,Naval Submarine,Mother Submarine,Future Submarine,Double Hull Submarine. 44 60 http://ijmt.ir/browse.php?a_code=A-10-450-7&slc_lang=en&sid=1 2026/02/52025/05/132024/10/252025/07/192025/10/6 1404/7/14 2026/06/82026/07/122026/07/152026/08/22026/08/5 1405/5/14 Farzad Eskandari Marine Industries Organization, Tehran, Iran f.eskandari9@gmail.com 0031947532846004612 0031947532846004612 No Mohammad Moonesun Faculty of Civil Engineering, Shahrood University of Technology, Shahrood, Iran m.moonesun@gmail.com 0031947532846004613 0031947532846004613 Yes Ataollah Gharechae Chabahar Maritime University, Maritime Engineering College, Chabahar, Iran a.gharehchahi@gmail.com 0031947532846004614 0031947532846004614 No

en Commercial fishing vessels account for 44% of global seafarer fatalities despite comprising only 2.3% of the merchant fleet, with equipment failure contributing to 31% of fatal incidents. The FMEA method critically underperforms in this context due to implicit equal weighting, non-unique Risk Priority Number (RPN) mapping, and subjective weight assignment. This study validates an integrated CRITIC-CODAS-FMEA framework, building on our prior application to composite Lenj hulls, by extending robust proof across navigation, refrigeration, and propulsion subsystems of fishing Lenj. Almost all failure modes are analyzed using expert elicitation (n=12 marine specialists). The CRITIC method derives objective weights by quantifying contrast intensity and inter-criterion conflict in S/O/D ratings, while the CODAS method employed Euclidean and Taxicab distances to resolve ranking ambiguities in the weighted space. The framework achieves 100% resolution of identical RPN clusters and elevates 89% of high-severity modes (S≥9) into top-10 rankings versus 60% for conventional FMEA. It demonstrated superior alignment with expert consensus (Spearman ρ=0.87 vs. 0.62) and 92% expert agreement versus 56% for RPN-based prioritization. This framework transforms risk assessment into a context-aware decision tool, objectively capturing marine operational realities to significantly enhance crew safety for the 34.3 million fishers operating worldwide. Maritime Safety,FMEA,CRITIC,CODAS,Multi-Criteria Decision Making (MCDM),Fishing Lenj. 61 80 http://ijmt.ir/browse.php?a_code=A-10-54-1&slc_lang=en&sid=1 2026/02/52025/05/132024/10/252025/07/192025/10/62026/05/22 1405/3/1 2026/06/82026/07/122026/07/152026/08/22026/08/52026/09/2 1405/6/11 Esmaeil Shafizadeh Department of Maritime Engineering, Amirkabir University of Technology e.shafizadeh@aut.ac.ir 0031947532846004632 0031947532846004632 No S. Hossein Mousavizadegan Department of Maritime Engineering, Amirkabir University of Technology hmousavi@aut.ac.ir 0031947532846004633 0031947532846004633 Yes

en Although research on port service quality has consistently shown that operational quality influences customer-related outcomes, it provides comparatively limited guidance on which cargo-handling dimensions should be preserved, accelerated or improved first. This study develops a priority-based assessment of cargo-handling operational quality by examining how operational speed, accuracy and error reduction, operational safety, and equipment availability and readiness should be ranked in relation to the continuance intention of organizational customers in a container-port setting. A cross-sectional survey was conducted among representatives of organizational customers directly involved in container loading and unloading activities at Imam Khomeini Port, yielding 110 valid responses. The analytical framework combined dimension-level multiple regression, Pratt-based relative-importance decomposition, importance–performance analysis and an action-priority score that integrated each dimension’s contribution to explained variance with its remaining performance gap. The findings showed that the four cargo-handling dimensions jointly explained 59.5% of the variance in B2B customer continuance intention. Operational speed recorded the largest standardized regression coefficient (β = 0.32) and the highest relative-importance share (35.4%), followed by equipment availability and readiness (β = 0.29; relative-importance share = 29.2%). When relative importance was considered alongside the remaining performance gaps, operational speed retained the highest action priority, followed by equipment readiness, operational safety, and accuracy and error reduction. Notably, although accuracy and error reduction received the lowest perceived performance score, its comparatively weaker contribution to continuance intention prevented it from emerging as the most urgent improvement priority. By moving beyond the question of whether cargo-handling quality affects customer continuance intention, this study demonstrates how individual operational dimensions can be translated into a defensible and practically meaningful sequence of managerial priorities. The proposed framework distinguishes statistical importance, perceived performance and improvement urgency, thereby providing port managers with a transparent basis for allocating limited operational resources while extending port service-quality research toward a more actionable and outcome-oriented approach to prioritization. Container ports,Cargo-handling operational quality,B2B customer continuance intention,Importance–performance analysis,Relative-importance analysis,Equipment readiness,operational reliability,Maritime logistics. 81 98 http://ijmt.ir/browse.php?a_code=A-10-8180-12&slc_lang=en&sid=1 2026/02/52025/05/132024/10/252025/07/192025/10/62026/05/222026/05/18 1405/2/28 2026/06/82026/07/122026/07/152026/08/22026/08/52026/09/22026/09/5 1405/6/14 Mohammad Soltani Shirazi Master of Science (M.Sc.), Department of Maritime Business Management, SR.C., Islamic Azad University, Tehran, Iran m.asadian@gmail.com 0031947532846004634 0031947532846004634 No Mohammad Asadian Ghahfarokhi Assistant professor, Department of Marine Industries, SR.C., Islamic Azad University, Tehran, Iran asadian@srbiau.ac.ir 0031947532846004635 0031947532846004635 Yes Seyed Reza Samaei Assistant professor, Department of Marine Industries, SR.C., Islamic Azad University, Tehran, Iran samaei@srbiau.ac.ir 0031947532846004636 0031947532846004636 No