港口合作竞争模式研究

我国港口发展迅速,现已初步形成协调发展的三大港口群,但是港口群内的港口和港口群之间的竞争激烈,导致港口资源的严重浪费。本文借鉴外国港口合作经验,在分析我国港口竞争现状的基础上,提出可行性的港口整合方案,以充分利用港口资源,发挥其在区域经济发展中的巨大作用。     

补给工作艇收放装置选型设计分析

工作艇是军辅船的常用设备,目前,国内对其在高海况下的安全收放问题尚无很好的解决办法.通过对"C"型单点起吊方案和"A"型双点起吊方案的对比分析、适用的状态分析,指出了各自的优缺点,同时在挂钩中设置了波浪补偿装置,综合考虑解决双点同步性的问题,从而保证了工作艇收放的安全性.     

关于公平对待海员与海事调查规则的分析——沉默权与不自证其罪

船员在海事调查中如何维护自己的权利,海事主管机关在海事调查中如何公平对待船员,文章从国际公约和国内立法现状的角度对这两个问题进行了分析。     

浅谈大型船舶舱口围地面组装及整体吊装方案

本文介绍舱口围地面组装及整体吊装方案实施过程中,如何进行精度控制,减少整体吊装变形,实现舱口围组装与舱口盖安装调试工作转移到地面完成。     

Forecasting container throughput based on wavelet transforms within a decomposition-ensemble methodology: a case study of China

To improve predictive accuracy, new hybrid models are proposed for container throughput forecasting based on wavelet transforms and data characteristic analysis (DCA) within a decomposition-ensemble methodology. Because of the complexity and nonlinearity of the time series of container throughputs at ports, the methodology decomposes the original time series into several components, which are rather simpler sub-sequences. Consequently, difficult forecasting tasks are simplified into a number of relatively easier subtasks. In this way, the proposed hybrid models can improve the accuracy of forecasting significantly. In the methodology, four main steps are involved: data decomposition, component reconstruction based on the DCA, individual prediction for each reconstructed component, and ensemble prediction as the final output. An empirical analysis was conducted for illustration and verification purposes by using time series of container throughputs at three main ports in Bohai Rim, China. The results suggest that the proposed hybrid models are able to forecast better than do other benchmark models. Forecasting may facilitate effective real-time decision making for strategic management and policy drafting. Predictions of container throughput can help port managers make tactical and operational decisions, such as operations planning in ports, the scheduling of port equipment, and route optimization.     

自航水雷沉底稳定性与自航性能的兼容性问题

在分析自航水雷对沉底稳定性和自航性能要求的基础上，提出了两种使自航水雷同时满足沉底稳定性与自航性能要求的方法，给出了相应的设计实例，并对设计结果进行了分析、讨论。     

水下隧道合理覆盖层厚度的有限元模拟研究

水下隧道覆盖层厚度目前基本上是凭经验确定的,采用不同的经验公式得到的计算结果差异很大。文章针对目前情况提出了采用有限元的求解方法,并结合公路隧道施工规范,模拟了拟建的重庆朝天门两江隧道在不同隧道覆盖层厚度时的拱顶位移和拉应力的分布及大小。通过与标准隧道的比较,得出了该隧道的合理覆盖层厚度,对同类工程有一定的参考价值。     

浅坑式钢轨翻转机

浅坑式钢轨翻转机用于对承轨台上的钢轨通过翻转进行调正、倒扣和平移,文章介绍沈阳铁路局科学技术研究所设计制造的浅坑式钢轨翻转机的技术参数和结构特点。     

异步牵引电动机容积功率、折算转矩和通用性问题的分析

提出异步牵引电动机容积功率和转矩折算的概念，并分析其与异步牵引电动机体积，质量，成本价格及通用性的关系。有利于异步牵引电动机的通用化，系列化设计。