Duyệt theo Tác giả "Dang Quoc Hai"
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Tài liệu Assessing ship collision risks in maritime transport based on seafarers’ experience(2024-01) Dinh Gia Huy; Dang Quoc Hai; Tran Anh KhaAssessing ship collision risks considering human factors presents persistent challenges due to the multivariate uncertainties faced by seafarers. Therefore, this study proposes a fuzzy-logic-based method to model ship collision risks in an area considering human factors. This method utilizes a hierarchical fuzzy system consisting of two fuzzy systems, fuzzy system 1 and fuzzy system 2, which are used to calculate the temporary risks and human factors, respectively. Aggregating the risks from both subsystems produces the overall collision risk index. This approach streamlines on-board risk appraisal, thereby reducing the navigator workload. While the current study delineates the risk modeling methodology, succeeding works validate the framework through simulated experiments. With adequate verification, this hierarchical fuzzy approach can assist next-generation risk-regulated navigation practices and enrich maritime agencies' traffic risk management.Tài liệu Development of a decision-making system for transportation in remote inter-island area(2024-01) Dang Quoc Hai; Pham Thai Hoang; Doan Thi Hoang Thao; Dinh Gia Huy; Le Thanh TienThe transportation of goods and people between islands poses distinctive logistical hurdles due to the geographical remoteness and varied infrastructure prevalent in island settings. This study introduces a theoretical framework designed to improve the efficiency of selecting and routing hub islands in an inter-island logistics network by utilizing the hub-and-spoke model. The process of identifying potential hub islands involves an initial assessment of several criteria, encompassing geographical, economic, and equipment-related factors. The utilization of Floyd's algorithm was employed in the computation of the shortest distance matrices between islands, with consideration given to the avoidance of ship collisions. The identification of the required hubs is determined by employing a location set covering model, which includes a constraint on the maximum distance for service provision. The p-Median model was employed to ascertain the most efficient hub locations to minimize transportation expenses. The framework provides a quantitative approach to designing efficient logistics networks for inter-island transportation. It considers important factors, such as shipping routes, hub locations, and collision avoidance. The utilization of this methodology holds promise for augmenting connectivity and streamlining resource accessibility in geographically isolated island areas with limited infrastructure.