互联网环境下的舰船电气设备检修系统

目前舰船电气设备检修系统存在检修耗时长、电流不稳定等不足,基于此提出互联网环境下的舰船电气设备检修系统设计。首先,通过数据接入层、网络层和应用层对舰船电气设备检修系统的总体框架进行设计,然后,通过在数据接入层接入数据串口UHST0和UHST1,与网络层的MN420H519芯片进行连接,将芯片存储的数据通过发光二极管、计数器等传入状态显示模块和检修分析决策模块,实现对互联网环境下的舰船电气设备检修系统硬件设计;最后,通过节点算法完成系统软件设计,至此完成互联网环境下的舰船电气设备检修系统设计。实验结果表明,与传统的舰船电气设备检修系统相比,提出的舰船电气设备检修系统的检修耗时更短,电流的稳定性高。     

起重船在犍为船闸检修中的应用

针对山区河流大型船闸检修问题,从投资性价比、共用性、便捷性等方面对检修闸门形式和起吊设备进行比较,从而确定犍为船闸“浮式叠梁检修门+起重船”的检修方案。详细描述犍为船闸检修的特殊性,并开展起重船在犍为船闸检修中的吊装工艺流程研究。通过经验总结、边界条件模拟等方法得出起重船在吊装超大型浮式叠梁检修门中的关键控制要素。详细介绍了起重船在山区河流大型船闸中起吊检修闸门的应用,为类似大型船闸检修提供了经验和借鉴。     

船舶副机检修中几个不容忽视的技术问题

在船舶副机的检修工作中有几项技术容易被检修人员忽视,从而引起检修效率下降和设备可靠性的降低。这几项检修工作在船舶副机管理中经常遇到,作者根据在不同船舶上管理不同型号副机的工作经验和教训进行总结。     

三峡船闸人字门顶升时机与工艺探讨

人字门的顶升检修是船闸检修的一个重要工程技术问题。文章对人字门顶升检修的方式、时机以及工艺进行了阐述,并提出了需要进一步研究和实践的问题。     

港口码头实用新型检修配电箱

在我国的许多港口,作为工程施工或平时维修以及驳船临时用电电源的检修配电箱,普遍存在防护性能差、使用不安全、外型不美观等问题.因此,有必要对检修配电箱进行技术创新,以提高检修工作效率和保证检修维护人员及设备的安全.     

阐述龙洲垸船闸检修技术方案

文章主要围绕龙洲垸船闸检修技术方案进行阐述,首先概述了检修的内容,而后深入阐述了检修的必要性和可行性,最后详细分析了施工方法要求、进度计划及时间。以供同类工程作为参考。     

主动服务 为船闸检修复航保驾护航

<正>11月30日,韩江丰顺东山水利枢纽船闸完成年度检修,于上午九点半恢复通航。在梅州海事人员的指挥协调下,当天共有80余艘船舶按照船闸管理规定进行排号登记,空载和重载船舶共40余艘安全有序通过船闸。据悉,该船闸于11月1日起进行为期一个月停航检修,因地处韩江中游,是梅州通往潮汕地区的必经水道,船闸停航检修,大量船舶停泊在船闸附近锚泊区。检修期间,梅州局多次派执法人员到现场了解船闸检修进展,要求施工方严格按照施工方案作业,落实安全管理措施,确保检修工作顺利进行,按时恢复通航。11     

风机的检修与维护

风机作为工农业中常用的气体压缩和输送机械,如何更为经济、有效、可靠地对其进行维护与检修一直是行业研究的重点,而对其进行状态监测和故障诊断,及时发现故障,从而制定基于状态的预防性的检修与维护具有重要意义.本文在总结风机常见故障及其排除方法后,对风机的常用检修与维护方法进行了阐述,接着状态监测和故障诊断在风机领域的研究现状...     

BIM技术在汉江雅口航运枢纽工程浮式检修闸门设计中的应用

针对浮式检修闸门内部结构复杂、难以进行浮游稳定性计算、工程算量困难以及图纸复杂等问题,结合汉江雅口航运枢纽工程浮式检修闸门设计的应用,探索采用BIM技术进行浮式检修闸门建立模型、稳定性计算分析、结构计算、正向设计生成二维图纸、辅助工程算量、校核审查、施工阶段的应用和运维阶段的应用等。结果表明:采用BIM技术,能够精确计算出浮式检修闸门的浮游稳定性,大幅提高设计人员出图和统计工程量的效率,确保设计质量。     

三峡船闸人字门底枢检修低位顶门方案

人字门是三峡船闸重要设备之一,其运行频次高,加速了底枢故障率的发生,必须定期实施顶升进行底枢检查与修理。目前,人字门检修通常是在计划性停航检修期间,采用高位顶门检修工艺,须实施拆除顶枢及启闭机构、固门等工序,适合工期较长的计划性大修项目。针对人字门底枢日常运行中可能存在的突发故障,提出在不拆除顶枢时对人字门低位顶门、应用底枢移出装备及配套工装实施底枢移出的检修方案。研究表明,该底枢检修低位顶门方案具有可行性,可为三峡船闸人字门顶门检修提供备选方案。     

弱矩阵项目管理考核机制的探讨

本文通过描述海洋工程施工领域的弱矩阵项目管理特点,重点论述当前项目管理所面临的项目考核激励机制所面临的难题,结合国内海洋工程建造企业的实际情况,就如何建立与海洋工程项目相适应的现代管理模式、方法和体系,重点对项目考核机制进行研究探讨,进而为如何建立适合弱矩阵项目管理的考核机制提供参考。     

Quantifying uncertainty in high-resolution coupled hydrodynamic-ecosystem models

Marine ecosystem models are becoming increasingly complex and sophisticated, and are being used to estimate the effects of future changes in the earth system with a view to informing important policy decisions. Despite their potential importance, far too little attention has been, and is generally, paid to model errors and the extent to which model outputs actually relate to real-world processes. With the increasing complexity of the models themselves comes an increasing complexity among model results. If we are to develop useful modelling tools for the marine environment we need to be able to understand and quantify the uncertainties inherent in the simulations. Analysing errors within highly multivariate model outputs, and relating them to even more complex and multivariate observational data, are not trivial tasks. Here we describe the application of a series of techniques, including a 2-stage self-organising map (SOM), non-parametric multivariate analysis, and error statistics, to a complex spatio-temporal model run for the period 1988–1989 in the Southern North Sea, coinciding with the North Sea Project which collected a wealth of observational data. We use model output, large spatio-temporally resolved data sets and a combination of methodologies (SOM, MDS, uncertainty metrics) to simplify the problem and to provide tractable information on model performance. The use of a SOM as a clustering tool allows us to simplify the dimensions of the problem while the use of MDS on independent data grouped according to the SOM classification allows us to validate the SOM. The combination of classification and uncertainty metrics allows us to pinpoint the variables and associated processes which require attention in each region. We recommend the use of this combination of techniques for simplifying complex comparisons of model outputs with real data, and analysis of error distributions.     

Integrated optimisation design of a dynamic umbilical based on an approximate model

An optimised design of a dynamic umbilical requires an extreme cross-sectional stress to be maintained within an allowable limit and a fatigue life to be guaranteed to be sufficient. It should be noted that a dynamic umbilical is a typical geometric bi-scale structural system. It consists of a local cross-sectional scale and a global configuration scale, which are significantly different in terms of geometric sizes. In this study, we established an approximate model to achieve an optimised design of the dynamic umbilical by considering the parameters of local cross-sections and global configurations simultaneously. The design variables of a dynamic umbilical are independently identified and defined at both local sectional and global configuration scales in the approximate model. Furthermore, we selected the maximum tension strain and the maximum bending moment, for covering local and global properties, as the objectives to be minimised. The approximate model was observed to be effective in integrating the local and global responses into one loop so that the computational efficiency could be significantly increased. We implemented the optimisation framework on a dynamic umbilical with a lazy-wave configuration, which is considered to be a basis for a case study. Furthermore, we verified the feasibility and effectiveness of the integrated optimisation strategy by numerical simulations. Moreover, we compared the optimised dynamic umbilical properties with those without optimisation. It was observed that the fatigue life of the optimised dynamic umbilical was improved significantly, thereby indicating that the integrated optimisation methodology provides a new model and algorithm for an efficient design of the dynamic umbilical.     

存在饱和输入的欠驱动船舶航迹跟踪控制

针对控制输入存在饱和限制的欠驱动船舶的航迹跟踪问题,提出鲁棒饱和控制方法。以船舶纵向速度和艏向角速度为虚拟输入,设计饱和运动学控制器,并引入二阶滤波器形式对控制器进行简化;利用反步法并引入Nussbaum型函数,设计饱和动力学控制器,以实现对任意光滑航迹的跟踪控制,并保证跟踪误差收敛至零点附近的一个有界区域内。仿真算例验证了设计方法的有效性和鲁棒性。     

Numerical analysis on free surface waves and stern viscous flow of a ship model

This paper deals with numerical techniques for computing the viscous flow past a ship hull with and without a free surface using a Reynolds-averaged Navier-Stokes solver with global conservation. In the first technique, a coarse grid is used to find an approximate solution to the free surface problem. Interpolation of a fine grid is subsequently carried out, and a more exact solution, particularly in the boundary layer and wake, is obtained. In the second technique, a modified Baldwin-Lomax model is introduced to compute the viscous flow with and without a free surface. These numerical techniques are applied to simulations of the flow around a Series 60 and an SR196C ship model. The results are compared with measurement data, and the usefulness of the numerical techniques is demonstrated.     

Optimal reefer slot conversion for container freight transportation

Given a fleet of container ships of varying capacity, a cost-efficient approach for improving fleet utilization and reducing the number of delayed containers is to optimize the sequence of container ships in a given string, a problem which belongs to the large ship-deployment class. A string sequence with ‘uniformly’ distributed ship capacity is more likely to accommodate a random container shipment demand. The number of one’s total ship slots acts as a gauge of the capacity of the container ships. Meanwhile, there are two types of ship slots: dry slots and reefer slots. A dry slot only accommodates a dry container, while a reefer slot can accommodate either a dry or a reefer container. The numbers of dry and reefer slots for ships in a string are different. Therefore, in this study, we propose a model that considers both dry and reefer slots and use it to elucidate the optimal ship-deployment sequence. The objective is to minimize the delay of dry and reefer containers when the demand is uncertain. Furthermore, based on the optimal sequence deduced, the study also investigates the need to convert some dry slots to reefer slots for the container ships.     

袋装固化土筑堤在沿海涂面整理工程中的应用

受制于砂石等建筑材料匮乏,浙江沿海围垦工程推进困难,寻找合适的替代材料迫在眉睫。因地制宜,就地取材,利用滩涂丰富的黏土资源,形成袋装固化土筑堤技术。即利用滩涂淤泥为原料,添加固化剂充灌袋体作为堤心代替砂石料等常规材料修建围堤。通过对固化土工程特性和袋装固化土围堤在外部荷载作用下的稳定情况进行研究,结合台州已建固化土围堤的经验和试验及检测资料,提出合理的计算方法,为固化土筑堤设计方法的建立提供可靠的依据。     

Impact of scale increase of container ships on the generalised chain cost

In recent years, an increase in the size of the container ships could be observed. The question is how these larger ships will influence the total generalised costs from a port of loading to a destination in the European hinterland. The second question is whether a scale increase of the container ships on other loops, such as a loop from the United States to Europe, has the same impact on the generalised chain costs as on the loop from Asia to Europe. A derived question is which element of the total chain has the highest importance, and whether this balance varies as the ship size changes. In this article, a model is developed that allows answering the above research questions. The model is designed to simulate the cost of a complete loop of a container ship and of a chain that uses that same loop. For the chain cost simulation, the maritime part is determined by the loop. From the ports of loading and unloading, the port container handling and the hinterland transportation costs are also integrated. The model also allows calculating the total chain cost from a point of origin (either a hinterland region or a port) to a destination point (also a port or a hinterland region). An actual container loop of a container shipping company can be introduced in the model. An application is made to two existing container loops, namely from Asia respectively the United States to Europe. It turns out that changing ship does indeed lead to economies of scale, but also that the impact is larger on the Asia–Europe connection than on the US–Europe connection. Furthermore, the maritime component has the biggest share in the total chain cost, but as ship size increases, the shares start getting closer to each other. This research contributes to the existing literature in two ways. First of all, it quantifies the impact of the scale increase of container ships throughout the total chain. Second, this is done from a bottom-up engineering modelling approach.     

A Training Framework for Understanding Conflict in the Coastal Zone

The coastal zone is attractive for human settlement because it tends to be resource rich, providing a good location to generate incomes and livelihoods. Equally, however, it is a complex and powerful natural environment, which means that the coastal zone often becomes a focus of conflict with multiple users competing for limited space and resources. Understanding the causes of, and determining solutions to, the ensuing problems requires inputs from a range of analyses across sectors and disciplines. However, different disciplinary and sectoral approaches frequently use different investigative methods, language, and means of presenting results. This article presents a framework that has been developed in collaboration with Indian institutions over the past three years in an effort to address some of these fundamental problems of analysis and translation into policy action. Key components addressed by the framework are strengthening the capacity to practice, knowing how to proceed and how to find out what needs to be known using experience-based problem solving.     

购建船舶与融资租赁船舶的财务决策研究

自上世纪九十年代以来 ,融资租赁船舶由于其投融资的特殊性在我国航运企业逐渐增多 ,如何进行购建船舶与融资租赁船舶的财务决策成了航运经济界探讨的一个重要问题。提出一种购建船舶与融资租赁船舶的差异现金流量财务决策方法 ,建立了在相同的财务风险条件下 ,购建与融资租赁船舶财务决策过程中租赁租金支付的盈亏平衡点公式 ,对这一盈亏平衡点公式作了进一步的论证。举例表明 ,所建立的融资租赁船舶租金支付的盈亏平衡点确定公式可以使购建船舶与融资租赁船舶的财务决策变得便捷而有效 ,对于其他行业购置与融资租赁某一资产的财务决策同样可以应用。