Uncertainty analysis of value for money assessment for public-private partnership projects

In recent years, private sectors are encouraged to take an active part in franchising of urban infrastructure investments and operations, which promotes the rapid development of public-private partnership (PPP) in infrastructure and public service supply. Value for money (VFM) assessment has been officially proposed to provide a reference for selection of projects planning to adopt PPP. Based on the bottlenecks of VFM application in China and the uncertainties for urban infrastructure PPP projects, a discounted cash flow (DCF) model is established for VFM of infrastructure PPP projects. Then, a Monte Carlo simulation model is established on the basis of uncertainty factors for VFM. Through the analysis of Huai’an trams PPP project, coping strategies of uncertainties for VFM are put forward. Findings of the research may propel the establishment of a complete VFM evaluation system for PPP projects. Key instructional functions of VFM during the process of decision-making can be brought into full play and PPP may develop orderly.     

CT reconstruction with priori MRI images through multi-group datasets expansion

Computed tomography (CT) reconstruction with a well-registered priori magnetic resonance imaging (MRI) image can improve reconstruction results with low-dose CT, because well-registered CT and MRI images have similar structures. However, in clinical settings, the CT image of patients does not always match the priori MRI image because of breathing and movement of patients during CT scanning. To improve the image quality in this case, multi-group datasets expansion is proposed in this paper. In our method, multi-group CT-MRI datasets are formed by expanding CT-MRI datasets. These expanded datasets can also be used by most existing CT-MRI algorithms and improve the reconstructed image quality when the CT image of a patient is not registered with the priori MRI image. In the experiments, we evaluate the performance of the algorithm by using multi-group CT-MRI datasets in several unregistered situations. Experiments show that when the CT and priori MRI images are not registered, the reconstruction results of using multi-group dataset expansion are better than those obtained without using the expansion.     

遗传算法在逆向物流网络规划设计中的应用

考虑到客户、初始回收点和回收中心3个层次的逆向物流网络,选择合适的回收中心,确定初始回收点个数和回收周期,基于一些基本假设,以最小化总的相关成本建立了1个内嵌两个指派模型的非线性混合整数规划模型,对符号体系和求解思路进行了分析.借助遗传算法,结合具体实例,给出了求解步骤和求解结果分析.     

基于SLP和生产物流的F公司车间设施布局改善

一个良好的设施布置设计可以使物料搬运的成本降低,使人员走动的距离缩短,从而使运作效率提高。运用SLP技术,对F公司CG片生产车间布局进行分析改善。首先,对该车间的生产流程和物流量进行分析,发现存在物料重复搬运、线路迂回、物流作业流程复杂等问题。然后,运用物流关系和作业单位相互关系图,经过尽可能小的调整,在能适应产品生产、工艺、流程等方面的情况下,降低物料搬运成本,求得合理的布置,从而使生产物流运作顺畅,达到提高整个生产系统经济效益最优的目的。最后,以物料搬运成本和厂房租金为评价指标,说明新布局的优越性。     

Shared pilot passage plan and navigational safety during pilotage

Navigating in confined waters with a pilot aboard requires that the pilot’s intention and plan is understood by all present on the bridge. The present study investigates the effect of having a detailed route plan and monitoring it in the context of pilotage. The aim was to see how the presence of a shared pilot passage plan in the Electronic Chart Display and Information System (ECDIS) affects the identification and recovery from navigational errors made by a pilot. Twenty participants, 10 with a shared route plan and 10 without, participated as navigators in a simulator scenario involving pilotage in the Oslofjord. Participants were bachelor students in nautical science. The navigation scenarios involved the intentional error by the pilot just before a predefined way point. Three measurements of relevance to navigational safety were recorded: (1) the time it took the participant to express concern, (2) the time it took the participant to correct the error (‘time to recovery’), and (3) the number of groundings. The study revealed that time to express concern and time to recovery were significantly much shorter for the group with a shared pilot passage plan presented in ECDIS than for the group without such a plan. Providing a bridge team with a shared pilot passage plan in ECDIS during pilotage might improve the ability to identify and correct navigational errors.     

螺旋桨非定常性能预估的面元法

本文建立了一个预估螺旋桨非定常性能的基于速度势的非定常面元法,该方法中采用了双曲面元,避免了面元之间的缝隙,并采用迭代方法实现非线性的等压库塔条件。文中以第22届国际水池会议(ITTC)推进技术委员会推荐的HSP桨与D4679桨和挪威船舶技术研究所(MARINTEK)提供的PF-W-B桨为算例进行了考核计算,与试验结果和其他研究工作者的计算结果比较表明,螺旋桨的非定常性能预报的结果是令人满意的。     

实行资源整合建设现代港口物流

现代港口和物流在业务功能上具有衔接性.本文通过分析物流与港口的关系,论述了如何整合现有资源的基础上,挖掘潜能,加强网络建设,提高其信息化水平,建设现代化的港口物流.     

回忆上海造船学会一二事

值此上海造船学会成立50周年之际,忆学会工作一二事,以表庆贺!     

露天皮带机除水装置的改进

武钢有输送矿石的皮带机268条,总长约为84 600 m,大部分在露天,雨天胶带极易积水,造成稀料现象,不但影响产品质量,也不利于设备的正常运转.     

鱼雷作战仿真系统中鱼雷联邦成员的设计

针对鱼雷武器作战分布交互仿真的需求，给出了鱼雷节点框架的设计思路和实现方法，实现了模型、接口、界面的分离，增强了鱼雷武器模型的可扩展性和可重构性；开发出鱼雷武器模型的基础类库和相关数据库，从而有利于用户对鱼雷模型的修改和维护。运行结果表明，经过上述改造的仿真系统运行稳定，为工程研制人员提供了友好的仿真软件。