船舶设计制造中的数据转换标准研究

随着CAD/CAE/CAM/VR技术在船舶设计和制造领域的推广应用,须要对迅速膨胀的数据信息进行大量的共享和交换.本文简要阐述了目前常用的IGES、DXF、STEP三种数据转换标准,介绍了这些数据转换标准的结构组成,并分析了不同数据转换标准的优缺点.     

基于Beta样条的船体型线交互设计系统的实现

本文介绍了一种基于Beta样条的船体型线交互设计系统。系统模拟手工设计过程,从型值表中自动读取型值并自动生在船体型线,曲线光顺性判别方法直观方便,图形输出方面可自动实现与Auto-CAD的DXF文件接口。     

SVG技术在B/S结构的船舶PDM图档管理中的应用

为了满足B/S架构下船舶PDM系统中设计图纸在线浏览的需求,提出了使用SVG（可升级矢量图形）这种基于XML的语言,对船厂设计部门的AutoCAD图形文件在网页上进行重绘。分别分析了CAD图形交换格式—DXF文件的结构和SVG文件结构,并探讨了CAD中的对象、DXF文件中的实体和SVG中的元素三者之间的关系。最后通过编程验证了方法的可行性。     

船舶辅机CAD/CAM集成系统

介绍了船舶辅机CAD/CAM集成系统，本系统由CAD、CAPP、CAM、技术文件采编等4个分系统组成，是在AutoCAD12.0基础上，利用AutoLISP,ADS(Borland C++)和Foxpro开发形成的。系统通过图形、DXF文件及数据库实现了各个分系统之间的集成。本系统已在企业应用，并有较好的推广价值。     

螺旋桨设计中的自动绘图程序设计

分析了螺旋桨图形的特点,使用高级语言开发了软件,将螺旋桨设计结果直接生成AutoCAD可以接收的DXF形式的文件,大大提高了工作效率。     

机器人等离子切割离线编程技术

机器人离线编程技术有着在线示教无法比拟的优势,离线编程技术便于和CAD/CAM系统结合,做到CAD/CAM/机器人一体化.通过分析等离子切割加工钢板的CAD图形自动生成的DXF文件,提取出待切割图形的信息,通过离线编程,生成等离子切割加工的机器人程序,并用OpenGL实现了等离子切割的仿真.     

基于STEP中性文件的船用柴油机关键零件CAD/CAPP集成方法的研究

基于STEP的CAD/CAPP信息集成,通常是开发专用产品零件的特征造型模块,该模块能按CAD/CAPP集成要求输出所需要的信息到STEP格式文件中,从而实现集成.但对引进产品,这种途径无法采用.针对上述情况,分析了引进产品的数据模型特点,提出以商品化软件输出的三维特征模型的STEP几何中性文件为数据源,提取待加工对象的几何参数数据信息,并结合匹配从三维特征模型中提取的公差等工艺制造信息,获得完整的产品零件的制造信息的方法来实施CAD/CAPP的集成.     

美国制定船舶设计软件新标准

据《亚洲航运》杂志报道,美国国际船用软件联合会(IMSA)最近宣布,一种船体几何定位通用中性计算机数据文件首获商业应用。该联合会由一些公司组成,他们致力于开创软件开发的中性标准。该协会制定的定位文件标准(IDF),虽然基本上与CAD标准如DXF和IGES相类似,但可提供专门适用于船舶的数据格式。这项标准允许与船体相关的数     

基于STEP中性文件的船用柴油机关键零件CAD／CAPP集成方法的研究

基于STEP的CAD／CAPP信息集成，通常是开发专用产品零件的特征造型模块，该模块能按CAD／CAPP集成要求输出所需要的信息到STEP格式文件中，从而实现集成。但对引进产品，这种途径无法采用。针对上述情况，分析了引进产品的数据模型特点，提出以商品化软件输出的三维特征模型的STEP几何中性文件为数据源，提取待加工对象的几何参数数据信息，并结合匹配从三维特征模型中提取的公差等工艺制造信息，获得完整的产品零件的制造信息的方法来实施CAD／CAPP的集成。     

基于STEP标准的船舶工程数据共享研究

本文介绍了在船舶设计和船舶工程研究等多个应用系统中,基于STEP标准的集成产品数据共享环境的基本结构。集成产品信息模型是集成产品数据共享环境的模型,其中目前有的信息模型STEP标准还不能支持,如：CFD,需要从几个相关的应用协议和集成资源扩展而来。本文最后从共享产品数据库的建立和访问两方面概要阐述了信息共享的实现。     

Errata

正In the paper"Influence of Fouling Assemblage on the Corrosion Behaviour of Mild Steel in the Coastal Waters of The Gulf of Mannar,India"in Vol.12,No.4,Page:509,References were lost,and the two authors’biographies were identical.The correct text is shown below.We apologize to the authors and our readers for any inconvenience caused by the errors.     

Journal of Marine Science and Application 2014 Sum. Contents

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第34届海洋、离岸及极地工程国际会议(英文)

正St.John's,Newfoundland,Canada,May 31-June 5,2015 OMAE2015 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to: meet and present advances in technology and its scientific support;     

联合作战计划和执行系统

全球指挥控制系统(GCCS)实施当前美国海军网络中心战信息基础设施的联合计划网络。联合作战计划和执行系统(JOPES)支持GCCS实现联合计划。JOPES有两类计划：时间不限的精密预案计划生成作战计划、方案计划或职能计划；时间敏感的危机行动计划生成作战命令或战役方案。前者在和平时期创建的作战计划是后者的计划基础，加速应付危机的能力。     

Eastbound or westbound ?

In terms of equal sailing distances, where is the inflexion when ships depart from ports in the Asian Continent to New York via Suez and/or Panama？
The answer is China South Port Group （Hong Kong, Shenzhen and Guangzhou）.     

Recent progress on wave induced loading measurements in warships

Recent measurements of wave induced hull strain and flexure in RN warships are presented together with the derivation of the current design criteria for extreme hull girder bending loads. The history of the development of the shipboard instrumentation used is given and recent developments to improve the quality and ease of analysis of the data are described. An unexpectedly high transverse asymmetry in the longitudinal strains measured in destroyers is shown to be the result of a combination of vertical and lateral bending in oblique seas. Finally recent theoretical comparisons between the loading of Deep-Vee hulls and conventional UK rounded bilge hulls are presented which demonstrate the higher loading experienced by this type of hull form.     

桥梁防撞设施物理模型试验

物理模型试验是预报防撞设施所受撞击力及优化设计方案的主要方法之一。结合杭州湾大桥柔性防撞设施及东海大桥独立式防撞体设计方案,阐述了船—防撞体撞击试验的基本原理、方法、试验方案及相关试验结果。提出了柔性防撞系统的优化方案。试验结果表明,该方案经济有效,可供预报类似桥梁防撞设施撞击力时参考。     

印尼某电厂码头水工建筑物设计

印尼某电厂项目码头水工建筑物包括码头、防波堤和护岸等主要组成部分。在该项目水工建筑物的设计过程中,综合考虑当地的自然条件、施工能力和材料来源等因素,不断优化结构选型和结构断面。根据不同使用要求,护岸分别采用直立式和斜坡式2种结构型式,推荐的设计方案节省投资、施工方便,可供同类工程设计参考。     

Impact of regulation on the performances of long-distance transport services: A comparison of the different approaches in Sweden and Norway

Despite the many socio-economic similarities between Sweden and Norway, differences in jurisdiction, organisation, cooperation, and financing of long-distance passenger train and coach services have led to the development of four distinctively different ways of serving the markets. This paper describes how the train and coach markets have developed in the two countries, with emphasis on regulatory and industrial structure and a couple of performance variables.Looking at passenger rail, both countries separated infrastructure from operation over a decade ago. However, while Norwegian rail is characterised by an almost monopoly supplier, rail services in Sweden are partly decentralised to the responsibility of county authorities and are widely subjected to competitive tendering. The rest of the network is about to be opened up for on-the-track competition. Swedish Rail (SJ) has spent the last decades consolidating its core business (passenger rail) and sold out its other businesses. In contrast, the Norwegian state rail (NSB) has expanded its business to become a major bus operator and property owner, with extensions also into the Swedish market.The coach industry was more recently deregulated in both countries. The Swedish coach market is dominated by privately owned companies operating services to and from Stockholm. In Norway, state-owned NSB is a major coach operator on medium distance routes, and is also the largest partner of Nor-Way Bussekspress which totally dominates long-distance coach services. Further, the Norwegian coach market is characterised by cross-ownership and cooperation which has enabled an extensive route network which covers most of Norway.We find distinct differences in achievements in the two modes and in the two countries. Swedish rail services have succeeded in winning market shares and in renewing and developing both infrastructure and service levels to a greater extent than the Norwegian model. On the other hand, the Norwegian coach market seems to be more developed and efficient compared to its Swedish counterpart.The paper concludes with a discussion on the possible links between the different approaches and the performance observed, with the aim to stimulate further and more detailed research on some important issues.     

开放式数据挖掘系统模型

目前国内已经出现了少量的数据挖掘相关产品。国内数据挖掘软件无论从数量还是质量上比较，都与国外软件存在着较大的差距。随着数据仓库技术的普及，数据挖掘应用的需求越来越强烈，如何缩短这种差距，研发数据挖掘软件产品成为国内业界的一个重要问题。通过引用目前国际通用数据挖掘标准技术来构建开放式的数据挖掘系统模型，该系统模型从可扩展性、可重用性、易用性等方面得到了加强。