Underwater sonar image recognition based on gray-spatial histograms

A new gray-spatial histogram is proposed, which incorporates spatial information with gray compositions without sacrificing the robustness of traditional gray histograms. The purpose is to consider the representation role of gray compositions and spatial information simultaneously. Each entry in the gray-spatial histogram is the gray frequency and corresponding position information of images. In the experiments of sonar image recognition, the results show that the gray-spatial histogram is effective in practical use.     

FGB法单面埋弧自动焊工艺试验及应用

介绍了称为FGB法的高效单面埋弧自动焊方法、材料、工艺试验、操作要点和应用情况,并与陶质衬垫CO2半自动单面焊工艺进行对比。     

8000吨级江海直达货船技术经济性论证分析

本文对8000吨级江海直达货船的载重量、航速、航道限制等基本要求和方形系数、主尺度选取以及营运效益等技术经济性作了初步分析研究.     

An ERP approach for container terminal operating systems

The major characteristics of ERP (Enterprise Resource Planning) are an enterprise-wide system that covers all the business functions and information resources, integrated database, built-in best industry practice, packaged software and open architecture. ERP enables reduction of system development time, flexibility, standardization of workflow and effective business planning capability. ERP is mainly for the manufacturing industry. However, the principles of ERP can also be applied to container terminal operating systems. This paper presents an ERP system approach for a container terminal. It has clustered the workflow of a container terminal and analysed the business process to generate the best workflows. The integrated database is designed to eliminate redundancy and keep integration. The core of ERP for container terminal is the planning facility such as berth planning and yard planning. The planning capability is very tightly coupled with data flow from client entities such as shipping companies. The ERP can handle the existing problems of container terminal operation that are mainly caused by lack of integration of a whole information resource in a container terminal, ad-hoc and poor planning capability, disconnected and incorrect data from client companies. The ERP approach can not only resolve the problems of container terminals but also promote adoption of information systems for container terminals in the world that have not yet implemented terminal operating systems.     

基于Linux的铁通公专网调度指挥平台的研究

介绍基于Linux的铁通公专网调度指挥系统的各功能模块及网络结构，阐述数据库访问控制、数据库操作控制、Lotus Domino与关系数据库之间的用户权限控制等关键技术问题。     

低阶大气环流模型的稳定性与分岔分析

研究了低阶大气环流模型的稳定性和分岔性质.用李亚普诺夫方法和定性理论分析了模型的稳定性,证明了全局一致渐进稳定和极限环的存在性,并给出了低阶大气环流模型的分岔条件.此外,研究了模型的Hopf分岔,并用规范形理论得到了Hopf分岔临界状态,最后运用数值仿真对所给的定理和条件进行了验证.     

分离式套拱加固带裂缝衬砌的变形规律试验研究

文章基于1∶10的相似比制作拱顶带单条纵向裂缝且裂缝深度为原衬砌厚度1/3的隧道二次衬砌模型,采用弹簧模拟地层抗力,进行了分离式套拱加固衬砌(原衬砌与新增套拱之间增设防水板)的径向加载试验,得出了带裂缝衬砌经分离式套拱加固后的变形规律与破坏模式。结果表明,在松动荷载作用下,分离式套拱加固结构的受力过程分为"初期加载—预制裂缝径向贯通、预制裂缝径向贯通—套拱拱顶裂缝径向贯通、套拱拱顶裂缝径向贯通—试件破坏"三阶段,破坏荷载由原衬砌拱腰截面控制,关键部位破坏顺序为拱顶开裂—拱腰断裂—拱顶破坏,整体破坏性质为脆性破坏。     

MBR法处理船舶含油污水技术的研究

随着人们环保意识的不断加强以及国际法规的日趋严格,传统的船用油水分离装置已不能满足含油污水处理的标准。本文简述了一些现有含油污水的处理技术,提出了MBR法在处理船舶含油污水中有极大的发展前景及今后需解决的问题。     

Mathematical approach for fleet planning under complicated circumstances

In order to facilitate the scientific management of large-sized shipping companies, fleet planning under complicated circumstances has been studied. Based on multiple influencing factors such as the techno-economic status of ships, the investment capacity of company, the possible purchase of new ships, the buying/selling of second-hand vessels and the chartering/renting of ships, a mixed-integer programming model for fleet planning has been established. A large-sized shipping company is utilized to make an empirical study, and Benders decom- position algorithm is employed to test the applicability of the proposed model. The result shows that the model is capable for multi-route, multi-ship and large-scaled fleet planning and thus helpful to support the decision making of large-sized shipping companies.     

Configuration estimation method for preliminary cost of ships based on engineering bills of materials

Ships are complex engineering structures that are designed and built on the basis of technical experience. A shipowner will often be required to estimate the price of a new ship on the basis of the value of comparable ships identified in trade journals. Similarly, shipbuilders are often interested in estimating approximate costs during the tendering phase in order to determine whether a ship is likely to be competitive for a particular order. Thus, when designing a ship prior to having obtained a contract, one of the most important processes is the estimation of approximate costs, including materials, associated labor, and overhead. During this preliminary design phase, the design is temporary and subject to change based on variations in the shipowner’s requirements. Hence, quick and flexible responses are key during this period and an integral aspect of the competitive powers of the shipbuilder. Given this environment, we propose a “configuration estimation method.” Our method is based on the configuration design method that is widely used in three-dimensional (3D) computer aided design (CAD) systems. We assume that a product lifecycle management system is furnished and that the cost is then estimated via the configuration of the ship, using an engineering bill of materials (E-BOM). In referring to the E-BOM, we utilize technical parametric costs derived from similar ships built previously. Using the proposed method, it is possible to obtain an accurate list of materials from the quotation, as well as a detailed work assessment for labor costs and overhead rates, so that reliable cost estimates can be generated quickly and flexibly. To demonstrate the practical applicability and effectiveness of the proposed method, we implement the prototype of a shipbuilding configuration estimation system by using a Microsoft Structured Query Language database and an E-BOM from AVEVA Marine version 12.01, which is a representative CAD system for shipbuilding.