一种舰船低频电磁干扰的整改方法与试验研究

为解决声呐系统的低频电磁干扰故障,基于电磁干扰三要素中的辐射耦合路径,提出了一种采用坡莫合金与波纹管相结合的电磁屏蔽整改方法。首先分析了电磁干扰的形成机制以及舰船平台上的常见类型,采用对比试验与电磁环境测试,掌握了此次电磁干扰的耦合路径;通过电磁屏蔽试验以及试验改进,验证了整改方法的可行性。在舰船上实施改进的整改方法,测试结果证明了该方法的有效性,解决了声呐系统的低频电磁干扰故障。     

预成孔置换强夯法处理大型油罐软基工程应用

建设大型油罐软基处理的重点在于控制工后沉降和差异沉降,但普通强夯置换法存在置换墩体着底情况不良与地基工后沉降量大的问题,针对这个问题进行了普通置换强夯法的改进研究。采取预成孔工艺能解决墩体着底情况不良的问题,从而减少地基工后沉降量。预成孔置换强夯法是一种用于处理软弱土地基的施工工艺,具有工期短、造价低与绿色环保等优点,通过预成孔保证置换墩着底可靠性,从而成功控制了工后沉降和差异沉降,实际检测结果和充水预压试验证实了处理方案的可靠性。     

超高层混凝土结构竖向变形分析与补偿研究

马来西亚四季酒店项目为342.5 m超高层混凝土结构,结构形式为框架-核心筒;依据施工现场合理的施工顺序及进度计划安排、不同施工阶段的高强混凝土特性的试验数据等,建立ETABS数值模型,分析出结构竣工和30年补偿周期时不同竖向构件的总竖向变形量以及相互之间的竖向变形差;施工过程中对已施部位监控点采取全程有效监测的方式来矫正分析数据,并采用"平层效应"和"层差补偿"的过程管控方式来弥补竖向构件的竖向变形量;最终通过分析比较结构竣工时现场监测点的实测数据与模型分析数据,验证了数据分析及竖向变形过程控制措施的合理性,取得了良好的效果。     

Analysis of cross effect on inherent deformation during the line heating process – Part 1 – Single crossed heating lines

This paper describes the effect of previous heating on inherent deformation by a subsequent heating line, more specifically, the case of two heating lines intersecting (crossing) each other. The paper has been divided into two parts. In the first part, the case of single crossed heating lines is studied in detail. The second part of the paper, discusses the case of more than one crossed heating lines. The novelty of the work lies in revealing the cross effect and how, factors such as, for example, the heating condition and the plate geometry, influence the resulting inherent deformation of crossed heating. In addition, relationships to easily get these influences are provided. The results are suitable for a wide range of heating conditions and plate thickness.     

全回转起重船多系统耦合运动响应仿真分析

根据运动学基本原理,计入船-吊物、船-锚链耦合影响以及起重船自身受到的外环境载荷,建立船舶多系统运动模型。利用MATLAB/Simulink软件进行仿真,对多系统耦合作用下的船舶运动进行数值分析。分别在不同的遭遇浪向角和不同的吊臂回转角下,对船舶在各自由度上的位移进行比较,得到其对船舶运动参数的影响规律。结果表明:起重船运动过程中因计入多系统耦合影响,自身运动也表现出更为符合实际的运动特性,为准确预报全回转起重船多系统的运动响应提供了更为科学的理论依据。     

Career development for women in maritime industry: organisation and socialisation perspectives

For centuries, the maritime industry has been a recognised place in society dominated solely by men, and even though there were women involved, they were mostly on the periphery. This research aims to fill the gap of women’s career development in this field, by investigating the relationships among the degree of organisational socialisation, women’s workplace culture, and the career development of women in the maritime workplace. The analyses are conducted with the structural equation model with 202 valid questionnaires. The results indicated that women’s workplace culture has a significantly negative relationship with the degree of organisational socialisation, and then in turn, it has a significantly positive relationship with women’s career development in the maritime industry. Finally, the results also indicate that the mediating effect of organisational socialisation existed between women’s workplace culture and women’s career development. According to the empirical analysis, this study makes conclusions as well as suggestions for the maritime enterprises as the reference for human resource management.     

Long-term impact of the Shinkansen on rail and air demand: analysis with data from Northeast Japan

This paper analyses how the high-speed rail construction in Northeast Japan (Tohoku) has affected total demand and interregional travel patterns. We use annual interregional passenger data from 1989 to 2012 and apply regression analysis with the demand between Tokyo and the Tohoku prefectures as the dependent variable. We distinguish particularly between the ‘Full-’ and the ‘Mini-’ Shinkansen, where the latter are branch services running with reduced speed. We find that the ‘Full-Shinkansen’ quickly increases rail and total public transport trips and generates additional rail demand year on year. The ‘Mini-Shinkansen’ impacts are less pronounced. Furthermore, our analysis shows that the Shinkansen has shifted some demand from air to rail once it started operation and increased rail share gradually. We therefore suggest that predictions of demand impacts should carefully distinguish immediate from gradual impacts. We also discuss differences in regional demand in that not all prefectures have gained equally from Shinkansen construction.     

复杂外形潜水器的动力学建模

为建立复杂外形潜水器精确的动力学模型,并基于模型设计控制算法,本文以DOE HD2+2无人遥控潜水器(ROV)为对象,应用计算流体力学(CFD)粘流方法与面元法预测水动力系数.为提高计算速度,在保证计算精度的前提下,采用多面体网格,进行网格优化,减少了流体域的网格总数.由于ROV几何外形不对称,基于最小二乘法分段拟合了阻尼力/力矩与速度的曲线,建立了耦合的阻尼矩阵和附加质量矩阵.最后,基于CFD计算的水动力系数建立了Matlab Simulink动力学仿真模型,并通过水池操控实验对所建动力学模型进行了有效性验证.     

面向复杂环境的LNG码头合理布局规模仿真案例分析

LNG船舶通过限制性航道进出港时须采取一定的管控措施,具有显著的排他性,布局LNG码头时须确定合理的码头规模,以保障港区各类船舶通航效率。基于多智能体复杂系统的混合模拟仿真建模方法,以宁波舟山港六横港区南侧岸线新布局LNG码头研究为例,建立不同的仿真情境,通过设定的指标进行评价分析,研判在一定通航管控措施条件下六横港区南侧LNG码头合理布局规模,为港口码头布局和岸线合理利用提供决策依据。     

The effect of crowding on public transit user travel behavior in a large-scale public transportation system through modeling daily variations

In this paper, the crowding effect in a transit vehicle is modeled in a time-expanded network that considers the daily variation in passenger flows. The study models the daily variation of in-vehicle crowding in a real large-scale transit system. A transit assignment for this real network is modeled and implemented by constructing a crowding cost function that follows the valuation of crowding and by using the reliable shortest path finding method. The direct application of the crowding model to a real network for the Utah Transit Authority indicates that crowd modeling with multi-user classes could influence public transportation system planning and affect the revenues of transit agencies. Moreover, the addition of the disutility factor, crowding, does not always appear to cause an increase in disutility for transit users.