Inland waterways are characterized by various bends, complex intersections and high traffic density. This complex inland navigation environment brings challenges to vessel traffic service (VTS) in managing inland water traffic. We propose a method to assess navigational risk of inland waters based on bi-directional PSO-LSTM algorithm and ship maneuvering characteristics. First, a bi-directional PSO-LSTM based ship trajectory restoration model is established to repair the Automatic identification System (AIS) data. Subsequently, ship behavioral characteristics are extracted from these repaired AIS data, based on which the model of ship navigation risk assessment in inland waters is established using window approach. Several case studies are conducted to verify this proposed method. The promising results attest that this proposed bi-directional PSO-LSTM algorithm outperforms the traditional neural network and trajectory restoration models. In addition, this navigational risk assessment of inland waters can effectively identify complex waters with high navigational risks, which are consistent with the actual situation. This research helps support VTS in regulating ship traffic in inland waters, thereby ensuring the safety of ship navigation on inland waterways.

In the context of maritime transportation, waterborne shipping has developed quickly and attracted significant attention. This paper aims to propose a ship path planning model based on optimal control to provide reference paths for ships, prioritizing navigational efficiency and safety considerations. Based on the optimal control, the ship path planning problem is transformed into a multi-objective optimization problem, taking into account the speed constraints of ships during navigation. Then, the cost function based on the multi-objective optimization is constructed. Dynamic programming and numerical simulation are utilized to solve the value function, which is inducted to generate reference paths for ships. In addition, a case study including 12 Origin-Destination (OD) pairs in the Port of Rotterdam is conducted to generate reference paths. The simulation results showed that the model is proven to have high applicability in generating reference paths of ships navigating within the confines of port waters. By enhancing navigational safety and efficiency, the model could be used to provide invaluable guidance to both the bridge team and pilotage work.

To ensure the safety of an underwater pipeline embedded within riverbeds, it is essential to evaluate its burial depth and penetration depth during the emergency anchoring of a ship. In this research, the mechanical behaviour of the entire anchoring process with considering the penetration depth of the Hall anchor in the riverbed silt, was holistically examined using experimental measurements, theoretical calculations and computational analysis. Mock-up Hall anchors (5 and 7.5 kg) were dropped at five different heights beforehand, and their transient velocities during the underwater motion were measured using a 2D image sonar. When the water is deep enough, the velocity of Hall anchor when it touches the ground is predominantly determined by its weight with regardless of the height of the drop. Moreover, a theoretical analysis was employed to investigate the behaviours of uniform motion at the state of equilibrium and infinite depths of water, and the exact coefficient of fluid resistance of the Hall anchor was presented. Computational analysis based on the formulation of the arbitrary Lagrangian-Eulerian method was proposed to examine the anchor in the riverbed silt and predict its penetration depth with considering the influence of boundary restrictions. In addition, the riverbed silt with a high moisture content was considered as a material with fluid features, which will be examined for fluid-solid coupling analysis with a Hall anchor by means of a constraint algorithm with a penalty function. The predicted value of the maximal penetration depth is reasonable and reliable compared with the empirical formula, which is crucial to evaluate the burial depth of underwater pipelines. A research approach for the penetration depth of a Hall anchor in riverbed silt was proposed and demonstrated by considering the entire anchor process through a combination of experimental, theoretical, and computational analyses.

Collision avoidance is a priority task for ensuring the safety of a maritime transportation system. However, for a ship towing system, which is characterized by multiple vessels and physical connections, the research works about collision avoidance is limited. Thus, this paper proposes a speed and heading control-based conflict resolution of a ship towing system for collision avoidance. Two systems compose the core of the proposed conflict resolution: the risk assessment system and the coordination control system. The risk assessment is to identify the conflict and determine the time of avoiding action by calculating the index of conflict and the available maneuvering margin. The coordination control is based on the model predictive control (MPC) strategy to cooperatively control two tugboats for regulating the position, heading, and speed of the manipulated ship. Simulation experiments show that according to the index of conflict, the time cost, and the fuel consumption, a selected operation of combined heading and speed can be recommended for a ship towing system to provide a safer and more efficient towage manipulation.

Reasonable cruise catering supply plays a vital role in the reputation and economic benefits of the cruise industry. The key to cruise catering supply lies in the balance between catering procurement and sales, and the difficulty lies in scientifically grasping many productions, procurement, and sales. First, this paper establishes a classic retailer inventory management system, then studies the procurement, processing, distribution, and safety inventory issues related to catering issues, and determines the various costs of cruise ship catering. Finally, this paper uses Simulink simulation software to establish cruise ship-related catering inventory management systems to study the relationship between catering food production methods, purchasing decisions, tourist demand, and cruise ship profitability. Compared with classic retailer inventory management, this catering inventory management system adopts more economical production methods and superior purchasing decisions, considering the particularity of the marine environment and tourist groups. And it obtains a more superior cruise catering supply plan.

With the growth of the shipping trade, inland water traffic is getting more prosperous than ever. Meanwhile, the shipping risk in inland rivers increases gradually. In this paper, a path planning model based on the safety potential field theory is proposed for inland ships from the perspective of navigation risk. Firstly, different navigation risks for inland ships are defined based on the safety potential field theory for three types of obstacles including static obstacles, dynamic obstacles and waterway bank walls. Secondly, different potential fields are used to quantify the different navigation risks. Then, the superposition field is formulated by summing the above three potential fields, and the spatial distribution of the safety potential field is obtained. Finally, the minimum navigation risk points on each cross section, which is perpendicular to the navigation direction, are selected to formulate the optimal path. In addition, a case study of overtaking scenario is conducted using the proposed model. The simulation results show that the model can effectively describe the navigation risk, which could be used to generate the optimal path for ships in inland rivers. This research is of great importance for ship navigation in inland rivers.

In recent years, ship exhaust gases have become an essential source of air pollution. A detailed study of ship exhaust emissions can accurately reflect air pollution intensity in ports with high waterborne traffic. In this paper, ship exhaust emissions in 2018 in the west area of Shenzhen port are estimated based on ship AIS data and fitting results between ship characteristics, including ship length, engines' power, gross tonnage, and maximum speed. This research reveals the emission distributions according to different ship types, months, and operation conditions. The results showed that the contribution rate of exhaust emissions of cargo ships and container ships is at the forefront, In contrast, ship emissions in hotelling and normal cruising are more significant than those in maneuvering and slow steaming conditions. The results presented in this research provide a basis for developing emission reduction measures in port area management and provide relevant experience to other world port areas.

Towing operations are highly reliant on the experience of the towing operators. Safety concerns arise when towing operations are subjected to environmental disturbances and dynamic traffic conditions. However, a systematic framework and approaches to enhance the safety and automation of towing operations remain lacking. This work proposes a framework of collision prevention of ship towing operations under environmental disturbance in near port waters. The focus is to prevent internal collisions between tug and assisted ship and provide early warning of possible collisions with other surrounding ships. A cooperative multi-agent control strategy is employed to specify the direction and magnitude of the towing force of the two tugs in real-time. Therefore, in the presence of environmental disturbance, the assisted ship can sail along the planned trajectory, and the acceptable safe geometric distance between each ship pair in the towing system is guaranteed. Further, a COLREGs-compliant collision alert system is designed to promptly remind the towing operators of a collision hazard with nearby ships, and different alert levels indicate different action obligations of towing operators. This proposed framework and developed methods are applied to a tandem towing system consisting of two tugs and one assisted ship to test its feasibility.

The flag state control (FSC) inspection is an important measure to ensure maritime safety. However, it is difficult to improve ship safety management efficiency using data mining due to the scattered and multi-source ship inspection knowledge. In this paper, the emerging knowledge graph technology is used to integrate multi-source knowledge for the FSC inspection. Firstly, an ontology model is built to systematically describe the knowledge and guide the construction of the data layer of the knowledge graph. Then, the BERT-BiGRU-CRF model is used to extract entities from the unstructured data of the FSC inspection. The extracted results are associated with structured and semi-structured data and stored in the graph database Neo4j to construct the knowledge graph. In addition, a case study of the FSC inspection knowledge graph of Dafeng Port in Yancheng, China, is conducted to verify the strength of the proposed method. The results show that the knowledge graph can correlate trivial knowledge and benefit the efficiency of the FSC inspection. Moreover, the knowledge graph can reflect the deficiency characteristics of ships and support the safety management of water transportation.

通过数值计算和图像处理技术,再现或预测工程对象的演化过程和发展趋势,为当前工程对象的设计、施工、管理提供指导意见,因此,数值模拟方法已经成为解决岩土工程难题和进行岩土相关科研的一种不可或缺的手段,且逐渐发展成为研究生和高年级本科生的一门必修课程.本文总结了数值模拟在岩土工程实践和科研中的重要性以及当前数值模拟教学存在的问题,创新性提出了一种以"工程问题"为导向,"数值软件+模拟分析"相结合的教学方法,并阐明了本文所提教学方法的内容和实施途径,提升课程教学质量的创新思路、举措、效果及反思,以及推广至相关岩土工程专业课程的应用前景.

由于影响水上交通安全因素较多,分析不同影响因素的重要性对研究水上交通安全有重要意义.以问卷方式分别调查海事管理人员、船员和引航员等3类人员对影响水上交通安全因素的看法.基于调查问卷结果,采用熵权法对影响因素进行重要性排序,并对3类人员的排序进行两两相关性检验.结果表明:3类人员对影响深圳西部水域水上交通安全的因素总体看法一致,最重要的影响因素是能见度和航道条件;两两相关性分析显示海事管理人员与船员和船员与引航员之间为中度线性相关,而海事管理人员与引航员之间为低度线性相关,这表明3类人员对风险因素的排名总体一致,此水域现阶段交通资源存在短缺和亟待改进的问题.该研究结果对制定此水域交通政策和提高水上交通管理服务水平具有重要的意义.

为了进一步提高学院实验教学质量,基于实验教学成绩评定标准,分析学院土力学实验课程教学现状和存在的问题,查找实验教学体系设计缺陷,在以往专业实验基础上增设专业基础实验,修订实验成绩评定方案,探讨实验教学改革及实验管理方式,优化实验教学成绩评定体系.结果表明,基于实验课成绩评定的实验教学改革能较好地改善实验教学效果,进一步完善实验教学方法,切实提高学生的创新和动手能力,培养其独立开展科学研究的能力和素养.

针对桥群水域船舶路径规划问题,分析桥群水域环境特征,建立桥群水域环境模型,利用Mike21软件对桥区水域进行流场分布建模,并对水动力模型进行仿真.通过建立桥墩紊流区模型,分析桥墩安全富裕量,计算桥墩安全区范围.结合AIS轨迹数据对转向点聚类分析并辨识其连通性,将其作为路径规划约束条件,建立基于数据驱动的桥群水域路径规划模型,采用粒子群优化算法(PSO)进行路径规划,实例验证方法的有效性.结果表明:数据驱动下的桥群水域路径规划更符合船舶实际航行特征,规划路径精度更高.

船舶碰撞往往会造成严重的损伤或损失.船舶在实际航行中,若碰撞不可避免,驾驶员应尽量调整至合适的碰撞态势(包括速度和角度),以减少碰撞损伤或损失.因此,需研究船舶碰撞不同态势下的损伤,并界定其临界态势.本文以两艘10000吨级单舷侧结构散货船为研究对象,以不同的速度、角度设计多个数值仿真试验工况,基于MSC.Dytran对船舶最危险的区间段进行有限元仿真分析,同时结合正交设计、改进后的BP-GA算法,建立综合指标,而确定其临界速度和角度值,并提出减少碰撞损伤和损失的建议,以指导船舶驾驶员如何应急操纵.结果表明船尾机舱段为最危险碰撞区间段,在此基础上得出临界碰撞速度值为2253 mm/s,并得出临界碰撞角度随实际碰撞速度的变化趋势.研究成果可为船舶碰撞态势的选择提供理论参考,并为船舶驾驶员在紧急情况下的应急避碰提供实践指导.

In order to ensure the safety and smoothness of the oil and gas transportation by submarine pipeline,it is necessary to analyze and assess the damage risk caused by the emergency anchor. By using a nonlinear finite element software known as the ANSYS /LS-DYNA,the present paper has been trying to restore the process of a certain anchor penetrating into the seafloor. To achieve the purpose,we have,first of all,built up a geometric model of the anchor,pipelines and seafloor,then the unit type and the real constant has been defined and then meshed the geometric model so as to work out a finite element model. Secondly, the contact and collision dynamic response between anchor and seabed was analyzed by penetration method,and the velocity change and energy dissipation in the process of anchor injection into the seabed was simulated. Thirdly,energy transformation between the anchor and seabed,the velocity and displacement of the anchor as well as the stress and strain state of submarine pipelines were obtained by selecting different anchor weights,different impact velocities and different seabed sediments. Finally,according to the output file of the LS-PREPOST processing program,the energy change curve,the velocity-time curve and the anchor's displacement curve of the model were obtained,the numerical simulation results can correctly show the energy dissipation and displacement changes of the anchor in the seabed. The results showed that when anchor was penetrating the seabed,the seabed dissipated most of the anchor's energy so that the impact energy of the anchor on the pipelines decreased. The injection energy of the anchor increased almost linearly with the increase of anchor's weight and bottoming speed. Furthermore,the injection energy of the anchor decreased with the increase of internal friction angle and cohesive strength of soil. The research of this paper can provide references for the safety protection of submarine pipelines.

At present,the marine accident investigation,such as interviewing ship's crewmembers and examining charts,is basically qualitative and more or less subjective in nature.Therefore,it has not been uncommon that related parties hold different points of view.In view of this issue,a finite element simulation method is proposed,which restores dynamically the process of the collision and compares the simulated structural damage with the actual damage.The results can be convincing collateral evidence.

Taking two 10000 DWT single-hull side structural bulk carriers as the research objects,the collision zones were divided into three sections:the bulb-bow section of bow,the cargo hold section of midship and the cabin section of stern.Based on the finite element simulation and the risk evaluation method,the most dangerous zone of the ship collision was defined by considering the collision force, structural damage,energy exchange,collision probability and collision consequence.In addition,the suggestions for reducing collision damage and loss were proposed.The results show that the cabin section of stern is the most dangerous collision zone and the crew should avoid the dangerous zone w hen the collision is inevitable.

The paper analyzes the dynamic response process when the anchor penetrates the seabed based on finite element analysis program ANSYS / LS-DYNA.It analyzes the influence of different factors such as anchor weight,water depth,anchorage height and seabed sediment on the penetration of anchors in the seabed.Ultimately the best safe depth of the subsea pipelines under the effect of the anchor device is determined.

圆管式夹层板是一种新型船舶防护结构形式,通过在单层壳舷侧填充圆管式夹层以提高船体的耐撞性能。由于舷侧夹层结构在增加船体耐撞性的同时增加了船体质量,因此需要对圆管式夹层板进行尺度优化,在确保舷侧耐撞性增强的同时,有效控制船体质量增量。以船首与船侧相撞为例,综合考虑撞深、能量吸收、极限撞击速度和质量,提出一种耐撞性优化指标。基于正交试验设计、BP（Back Propagation）神经网络和遗传算法,得出最优的夹层板尺度,并利用有限元仿真软件MSC/Dytran对船舶碰撞进行数值仿真,从而确定最优的耐撞性舷侧结构设计。结果表明,优化后的舷侧圆管式夹层板结构在提高耐撞性能的同时能较好控制船体质量增量。研究成果在夹层板舷侧结构耐撞性能优化方面具有重要的作用,也为其他新型舷侧结构耐撞性能优化设计提供了参考。

精致化以管理理念、教育模式和价值追求为理论内涵,强调科学管理与人本管理相结合,提倡“人本性”、“科学性”、“绩效性”和“可持续性”.随着研究的不断深入,精致化管理理念的研究已经从基础教育延展至高等教育领域.在高校教学管理工作中,队伍建设、管理理念、管理方式方面存在不足,而精致化管理有助于借鉴先进的管理办法弥补教学管理工作中的盲点,为改进高校教学管理水平提供有利支撑.