Development of Bayesian Network Models for Risk-Based Ship Design

在过去的十五年里，轮船安全处理的注意开始通过整个海上的工业作为一个目的而非限制扫了。基于风险的轮船设计(RBD ) 方法论，在常规设计过程以内倡导风险评价的系统的集成开始了到起飞。尽管有这宽识别和增加的流行，能潜在地破坏结果的质量的重要因素在风险评价过程期间来自量、质的方面。这份报纸由通过与数据通过第一原则的途径产生了相结合的历史的数据的有效存储并且处理为风险评价开发形式化的方法论详细说明一个有希望的解决方案。这个方法应该帮助在能在设计舞台为决策被采用的选择站台(贝叶斯的网络) 产生适当风险模型。

Study of the ship design process model for collaborative design

The ship design process model is the basis for developing the ship collaborative design system under network environment.According to the characteristics of the ship design, a method for dividing the ship design process into three layers is pat forward, that is project layer, design task layer and design activity layer, then the formalized definitions of the ship design process model, the decomposing principles of the ship design process and the architecture of the ship collaborative design (SDPM) system are presented. This method simplifies the activity network, makes the optimization and adjustment of the design plan convenient and also makes the design process easier to control and change, at last the architecture of the ship collaborative design system is discussed.

Numerical Simulation and Experimental Research on Wake Field of Ships Under off-Design Conditions

Different operating conditions （e.g. design and off-design） may lead to a significant difference in the hydrodynamics performance of a ship, especially in the total resistance and wake field of ships. This work investigated the hydrodynamic performance of the well-known KRISO 3600 TEU Container Ship （KCS） under three different operating conditions by means of Particle Image Velocimetry （P/V） and Computational Fluid Dynamics （CFD）. The comparison results show that the use of PIV to measure a ship＇s nominal wake field is an important method which has the advantages of being contactless and highly accurate. Acceptable agreements between the results obtained by the two different methods are achieved. Results indicate that the total resistances of the KCS model under two off-design conditions are 23.88% and 13.92% larger than that under the designed condition, respectively.

Evaluation and selection of the ship collaborative design resources based on AHP and genetic and simulated annealing algorithm

The characteristics of the design resources in the ship collaborative design is described and the hierarchical model for the evaluation of the design resources is established. The comprehensive evaluation of the co-designers for the collaborative design resources has been done from different aspects using Analytic Hierarchy Process (AHP),and according to the evaluation results,the candidates are determined. Meanwhile,based on the principle of minimum cost,and starting from the relations between the design tasks and the corresponding co-designers,the optimizing selection model of the collaborators is established and one novel genetic combined with simulated annealing algorithm is proposed to realize the optimization. It overcomes the defects of the genetic algorithm which may lead to the premature convergence and local optimization if used individually. Through the application of this method in the ship collaborative design system,it proves the feasibility and provides a quantitative method for the optimizing selection of the design resources.

Modeling and designing for ship steering integrated simulator

The modeling of a ship steering integrated simulator(SSIS)applied to the design,debugging and maintenance of an autopilot is discussed.A nonlinear responsive model is proposed and applied to the design of SSIS.The SSIS generates real signals of the ship heading,the rudder angle,the ship position and the output to the autopilot.A variety of factors,such as ship speed variety,shallow water effect,nonlinearity of yaw and actuator,and environmental disturbances like wind,wave and current are considered carefully.Detailed formulas for calculating relevant parameters are provided.Taken a naval ship as an example,the physical-digital simulations on SSIS and the digital simulation on a Marine System Simulator(MSS)were conducted separately in various sailing conditions.Simulation results show that the simple nonlinear responsive model can be applied to ship motion control and simulation with sufficient accuracy and effectiveness.

The design of double line five step ship lock of Three Gorges Project

The general design and layout of the double-line five-step ship-lock,the water delivery technique for high head ship-lock,the key technical problems of fully lined ship-lock and the monitoring techniques for large-scale miter gates and hoisting equipment under complicated operation conditions of Three Gorges Project (TGP) are introduced.Since the operation of ship-lock in 2003,the operation practice has proved that the design techniques are advanced,rational and reliable.The design and construction of the fully lined ship-lock promotes the development of design theory and practice of ship-lock projects,which makes the construction technology of ship-lock in the world reach a new level.

Knowledge-based engineering approach for the support of ship structure design

The paper presents a knowledge-based engineering(KBE)approach for ship node components design.In the ship design process,many design tasks need design experiences to support.However,a ship design process is a complicated process with many simultaneously repetitive and time-consuming activities.In this research,the method combines KBE with Tribon system's built-in development language tools of Vitesse,captures and applies design knowledge for achieving standard components intelligent design modeling.A case study and industry implementation illustrate the feasibility of the proposed methodology.The KBE technique can provide not only proper references,suggests and supports but also knowledge integrated in the ship structure design.Especially,these rules related to the design can avoid lots of design mistakes.During the ship design stage,getting more precise and better designs will not only reduce the time of rework and wasting resources but also shorten the construction time,improve quality and profit.

Compatible Design of the System to Detect Ships and Airplanes with a Ground Wave Over-the-horizon Radar

This paper provides a design method based on a time-shared form, which obtains the compatibility of signal and the system for detecting both ships and airplanes. Then, it gives the structure diagram of the system and the chart diagram of signal processing. Finally, the continuity problem of signal modulation for ship detection is discussed.

Designing Container Shipping Routes for Heterogeneous Fleet for Coastal Services

Shipping companies operating liner services keep facing a high level of competition because of the increasing demand for these operators to provide fast, efficient, effective and reliable service. It is challenging for these liner operators to offer such services and still be competitive without strategic planning. It, therefore, makes planning and scheduling of shipping routes essential for the smooth operation of liner ships, especially shipping lines operating heterogeneously mixed size fleets. This paper aims to solve a heterogeneously mixed size fleet problem by using an operation research method with the implementation of linear programming to develop optimal shipping routes for a fleet of five vessels serving six coastal ports to get optimal results. An optimal solution to the problem is found with only two routes selected as the optimal shipping routes out of four routes that are considered. The results also showed that a vessel can be assigned to multiple shipping routes.

Simulation and Reasonable Design of Bridge Steel Fenders to Reduce Ship Impacts

Steel fenders are increasingly used for ship-impact resistance structures in the design of navigable bridges. As an important approach to investigating this anti-impact structure effectiveness to reduce influences of vessel impact, simulation analyses are still not perfect yet. So this paper is intended to discuss several issues related to ship collision simulations, including steel constitutive relationship, connections between steel box and pile cap, contacts definition and friction consideration, and the determination of impact waterlines and angles. Consequently based on two examples of ship-steel fender-bridge structure systems, some conclusions about effectiveness and design of fenders to reduce ship impact are drawn.

Adaptive robust dissipative designs on straight path control for underactuated ships

An adaptive robust control algorithm for ship straight path control system in the presence of both modeling uncertainties and the bounded disturbances is proposed. Motivated by the backstepping approach, the algorithm is developed by using the dissipation theory, such that the resulting dosed-loop system is both strictly dissipative and asymptotically adaptively stable for all admissible uncertainties. Also, it is able to steer an underactuated ship along a prescribed straight path with ultimate bounds under external disturbances induced by wave, wind and ocean current. When there are no disturbances, the straight path control can be implemented in a locally asymptotically stable manner. Simulation results on an ocean-going training ship ‘YULONG＇ are presented to validate the effectiveness of the algorithm.

A New Rational-based Optimal Design Strategy of Ship Structure Based on Multi-level Analysis and Super-element Modeling Method

A new multi-level analysis method of introducing the super-element modeling method, derived from the multi-level analysis method first proposed by O. F. Hughes, has been proposed in this paper to solve the problem of high time cost in adopting a rational-based optimal design method for ship structural design. Furthermore,the method was verified by its effective application in optimization of the mid-ship section of a container ship. A full 3-D FEM model of a ship,suffering static and quasi-static loads, was used as the analyzing object for evaluating the structural performance of the mid-ship module, including static strength and buckling performance. Research results reveal that this new method could substantially reduce the computational cost of the rational-based optimization problem without decreasing its accuracy, which increases the feasibility and economic efficiency of using a rational-based optimal design method in ship structural design.

大型耙吸挖泥船结构设计要点

为实现大型耙吸挖泥船结构设计安全、合理、可靠,以某大型耙吸挖泥船为例,分析大型耙吸挖泥船结构设计特点,从结构设计、强度评估、疲劳评估和振动评估等角度论证其设计要点,通过对泥舱结构设计分析,给出泥舱设计的关键节点,对关键节点进行强度分析和疲劳分析,结果表明,该船局部关键区域应力水平较高,低周疲劳在关键区域的疲劳中占据主要地位,建立三维有限元模型计算挖泥船固有频率,对比该大型耙吸挖泥船激励频率与固有频率,结果表明,船体总振动固有频率通常可以避开激励频率,生活楼固有频率与激励频率较为接近。

Design and Comparative Analysis of Small Modular Reactors for Nuclear Marine Propulsion of a Ship

The fast growth in the size and difficulty of nuclear power plant in the 1970s produced an interest in smaller, modest designs that are intrinsically safe over the usage of design features. With the development of nuclear technology, there is the need for revolution in the Maritime sector, especially the advance marine propulsion. In current years, numerous reactor manufacturers are dynamically improving small modular reactor designs with even superior use of safety features. Several designs integrate the ultimate in greater safety. They totally remove specific accident initiators from the design. Other design features benefit to reduce different types of accident or help to mitigate the accident’s consequences. Although some safety features are mutual to maximum SMR designs, irrespective of the coolant technology, other features are specific to liquid-metal cooled, water, gas, or SMR designs. Results: There have been more reactor concepts investigated in the marine propulsion area by different assemblies and research laboratories than in the power generation field, and much can be learned from their experience for land applications. The extensive use of safety features in SMRs potential to make these power plants extremely vigorous, protecting both the public and the investor. Conclusion: For these two considerations, it is recognized that a nuclear reactor is the ideal engine for naval advanced propulsion. The paper will present the work to analyze the concept design of SMRs and design a modular vessel consisting of a propulsion module.

吨税制度对国际海运业的政策效应——基于多期双重差分模型的检验

国际海运业风险大、周期长,其高质量发展离不开国家政策的支持。国际经验表明,对国际海运业实施吨税(Tonnage Tax)可以提升本国船舶运力,促进其发展。基于1994-2021年《海运业年度审查报告》统计的拥有吨位在世界前列的24个国家相关数据,运用多期双重差分模型实证检验吨税对国际海运业的具体影响后发现,实施吨税可以吸引船舶在本国进行登记,提升悬挂本国国旗的吨位占比以及增加船舶吨位,提高本国国际海运业的竞争力。异质性分析表明,吨税制度对税负水平较高国家的影响大于税负水平较低的国家,对非欧洲国家的影响大于欧洲国家。我国应适时引入吨税,为国际海运业提供良好的营商环境。我国吨税设计宜采用荷兰模式,明确只有国际海运以及与其直接相关的辅助活动才能适用,设置合理的锁定期,允许国际海运企业自行选择适用吨税或是企业所得税。

基于贝叶斯分类器的船舶型材优化设计

船舶结构轻量化设计对于提高船舶的运载能力和实现更大的经济效益具有重要意义,针对传统优化设计方法建立优化模型时约束条件无显式表达的问题,提出基于贝叶斯分类器的船舶型材优化设计方法。首先,依据贝叶斯理论和核密度估计方法构建贝叶斯分类器,然后利用贝叶斯分类器代替隐式约束函数进行求解,最后以T型材的优化设计问题为例进行验证,并将优化结果对比约束条件可显式表达情况下的求解结果进行分析。基于单约束条件的贝叶斯分类器目标函数偏差低于2%,基于多约束条件的贝叶斯分类器求解目标函数偏差在8%左右,且不同的贝叶斯分类器设计方法会对优化求解结果精确程度产生影响。使用贝叶斯分类器做出决策边界能代替实际边界进行优化求解,验证了贝叶斯分类器驱动求解器寻优的可行性,对解决约束条件无显式表达的问题提供了新思路。

豪华邮轮结构设计特点与分类设计技术

考虑到现代豪华邮轮已经由传统意义上的远洋交通工具演变为海上休闲娱乐的重要载体,设施齐全,功能多样,可以容纳更多游客的高、大、长上层建筑成为豪华邮轮最显著的特点,通过分析豪华邮轮多甲板、长上层建筑船体结构的静力及动力响应规律,总结出豪华邮轮船体平均应力水平低、高应力区域多、板薄易屈曲、振动噪声分布不均衡的整体特点,从顶层设计的角度提出分类设计技术。