对超大型船舶实施护航拖轮监护的探讨

分析了宁波-舟山港南航道弯曲复杂、狭窄难行的安全风险。阐述了对超大型船舶实施护航拖轮监护的必要性和可行性。得出结论:采用护航拖轮对超大型船舶实施监护是一种安全高效的减少航行风险的措施。最后提出了对超大型船舶实施护航拖轮监护的初步方案。     

基于价值链的中海集运公司风险管理

现代海运业具有"高投资、高风险、高收益"的特点.由于风险众多而分散,传统的企业风险管理模式已难以满足现代航运企业对于风险管理的需求.从系统和集成的角度出发,提出了基于Hines价值链的航运企业风险管理模式,将航运企业面临的风险分为企业内部风险、企业间风险、价值链外部风险等3个层次;针对不同层次的风险宜采取不同的风险处理策略,并特别论述了上述3层次风险之间的关联性.作为案例,对中海集运公司的风险管理实践进行了剖析.结论表明,我国航运企业在企业内部风险管理方面已积累了丰富的经验,并开始重视通过企业间合作来削弱企业间风险的影响,但在价值链外部风险上尚乏举措,在风险管理文化的构建上亦有待深化.     

Determinants of Indian sub-continent officer–seafarer retention in the shipping industry

The retention of officer–seafarers within the international shipping industry is a difficult problem facing shipping and ship management companies. One strategic option open to all companies that should improve overall retention is to seek to become an employer of choice by providing an intellectual capital environment attractive to officer–seafarers. This is investigated through a survey of officer–seafarers covering areas where ship management can exercise some control over their working conditions. These cover recognition by their employer and commensurate rewards, organizational culture and structure and building relationships with external parties. Experienced Indian sub-continent officer–seafarers were the sample population resulting in more than 200 valid completions. These were analysed using correlation and regression. Although all hypotheses were in the predicted direction, only four passed the significance test: long-term career prospects, a smooth and fair recruitment process, a better relationship with maritime authorities and an employee-friendly organizational culture. Stepwise regression indicated that only organizational culture had a significant positive effect on intention to remain a seafarer. The items in the organizational culture construct accord with recommendations from the literature on becoming an employer of choice and improving employee retention, providing guidance for attracting and retaining officers.     

金融危机下福建船舶企业防范风险的策略和思考

世界性金融危机对全球的船舶市场产生巨大影响,而福建船舶业也难以独善其身。如何应对金融危机,并从战略的高度提出一系列的防范对策与措施,是当前每一个船舶人都需要面对的重要课题之一。这场金融危机所造成的潜在风险可能来自船东或金融机构一方,也可能直接就来自企业本身,对此要有足够的认识;当然,危机既包含着巨大的风险,同时也孕育着莫大的机遇。如果我们在沟通信息、扩大融资渠道和苦练内功等方面有所作为,谋定而动,就一定能够让福建的船舶企业淌过险滩,再创佳绩。     

Managing Beach Amenities to Reduce Exposure to Coastal Hazards: Storm Water Pollution

Despite posted warnings and educational campaigns warning about the health risks associated with storm water pollution, swimmers continue to swim in coastal areas polluted by storm water runoff. This study uses a simple spatial model of beach visitation to show how beach amenities and storm drains influence the way in which beach goers choose to locate themselves at beaches in Santa Monica Bay, California. The estimated models indicate that passive means of preventing exposure to marine pollution (e.g., posted signs) could be made significantly more effective if combined with the active management of other beach amenities. Similar methods also could be used to reduce risks to swimmers from other hazards including riptides and boat traffic.     

株洲二线船闸闸门及启闭机优化设计

株洲二线船闸人字门为超大型闸门,控制闸门的变形量是设计的重点和难点,船闸启闭机集中布置在闸首上部,需充分考虑吊装及检修方便。闸门门体结构进行多方案布置,分别进行结构计算,研究结构本身抵抗变形的能力,对闸门的附件进行优化设计。启闭机布置采用两种方案,并进行优缺点比选,重点考虑吊装、检修、通行、美观等因素。结果表明,闸门采用多主横梁+八隔板+水平次梁的方案刚度最好,防护系统及人行桥优化设计后更趋合理,启闭机布置采用空箱+吊物孔电动盖板方案,实现了吊装检修和通行方便。     

OCS development: A community's acceptance of risk

Abstract

Port O'Connor, Texas, a small unincorporated community on the Gulf Coast, was studied to assess the residents’ attitudes toward the potential growth related to Outer Continental Shelf (OCS) development. In contrast to attitudes of residents in many East Coast communities, residents of Port O'Connor do not feel threatened by OCS‐related growth. Rather, the risks they perceive result from increased tourism. They are well familiar with the social costs of tourism. They are less familiar with the social risks involved in increased OCS activities.

In terms of coastal zone management policy, this study highlights the importance of attending to the concerns of local residents for their social structure and way of life. The social risks imposed by increased OCS activity must be considered important factors in plans for OCS development.     

珠江三角洲平面二维盐水入侵数值模型研究

珠江三角洲咸水入侵是一个近年来备受关注的课题。珠江三角洲河道纵横交错,口门数目众多,水动力因素错综复杂。数学模型以其经济、省时的优势成为珠江三角洲咸水入侵预报的主要研究手段。该模型网格采用三角形与四边形结合的混合网格形式,计算区域包括珠江三角洲网河区、八大口门以及外海部分海区。采用同步水文资料对珠江三角洲的盐度场进行了模拟,验证结果显示模型计算的潮位、流速、以及盐度等与实测资料吻合较好,模型成功复演了珠江三角洲的潮流和盐度的变化过程。在模型验证良好的基础上,通过计算1999年和2005年不同地形条件的咸潮上溯情况,可知由于河道地形下切严重已导致2005年咸潮上溯程度明显加剧,给更多居民日常用水带来困扰。     

复杂轴承支撑结构动力学特性的有限元方法研究

复杂轴承支撑结构由多个子结构组合而成,从而形成多个接触面.研究表明,这些接触面的存在对结构的动力学特性有着显著地影响,其对振动信号的衰减与反射是振动信号提取过程中的一个难题.针对这个问题,建立轴承支撑结构的有限元模型,利用Ansys Workbench对结构进行模态计算和传递函数的计算,采用与整体结构对比研究的方法,考虑螺栓预紧力的变化对结构振动特性的影响,分析结构受冲击载荷激励时响应的特点.结果表明,随预紧力的增大,各阶模态呈增大趋势,螺栓结构对高频信号的衰减作用更加明显,轴承故障信号在复杂传递路径中难以有效的传递.     

浅谈船舶造修企业安全生产管理的一点体会

船舶造修企业生产经营活动的特点是:国家相关部门严格监管的"特种设备作业人员作业种类与项目"多。因这类作业潜在的风险会造成诸如"火灾、爆炸、灼烫、坠落、挤压、触电、坍塌、淹溺、中毒、窒息等导致人身伤害和财产损害的生产安全事故"。因此,要搞好船舶造修企业的生产安全,就必须坚持国家"安全第一、预防为主、综合治理"的安全生产方针。     

Crucial factors influencing international logistics operations for African landlocked countries – A case study of Burkina Faso

ABSTRACT

This study aims to evaluate the crucial factors influencing international logistics operations for African landlocked countries. To this end, a case study and a questionnaire survey were conducted. A total of 147 usable responses from container shipping firms were obtained as a result of the questionnaire survey. The results of factor analysis revealed that transportation capability, external risks, information integration, logistics infrastructure, local agents’ logistics capability, and national law and policy were crucial factors influencing the logistics operations of African landlocked countries. Specifically, local agents’ logistics capability was perceived by respondents to be the most important factor. Moreover, the results of the study also indicated that the highest factor mean values of small shipping companies were related to transportation capability, external risks and the local agents’ logistics capability, whereas container shipping companies that arranged trucks for inland transportation paid more attention to the external risks, logistics infrastructure, the local agents’ logistics capability, and national law and policy.     

超声波检测残余预应力的理论探讨

残余预应力是预应力构件的重要特征参数,关系到构件的承载力大小和安全状况。残余预应力与诸多因素有关,且关系很复杂,准确计算残余预应力是非常困难的。因此,对已建成结构进行现场检测是获得残余预应力的有效方法。在这样的背景之下,文中引入超声波来检测预应力钢筋或钢绞线的残余预应力。根据声学和力学的理论知识,推导了残余预应力的计算公式。在推导过程中考虑了温度补偿。在测量承载构件的残余预应力时需要测量纵横超声波的声时和计算外荷载产生的弯矩分布。     

海事系统重点建设项目社会稳定风险评估

文中结合海事系统重点建设项目的特点,对其潜藏社会稳定风险的评估内容、评估程序以及处置对策进行探讨。     

一种基于增量定位的移动信标辅助节点定位算法

针对网络中可能有少量节点难以接收足够定位信息的情况,提出一种基于增量定位的移动信标辅助节点定位算法。该算法初步考虑节点之间的协作,选取部分节点对接收信息进行转发。仿真结果表明,在移动信标的路径长度和通信半径不变的情况下,该方法可获取较高的定位覆盖率,适用于信标路径间距较大的场合。     

Strategic intent: Guiding port authorities to their new world?

Following the financial tsunami many organisations are facing greater risks to their sustainability. Strategic collaborations in logistics networks, of which ports are a significant node, reduce risks for all organisations in the network, increase an organisation's ability to access efficiencies such as economies of scale and create opportunities for learning. The knowledge learnt from collaborators is enhanced by managing the key relationships and forming a strategic intent to learn for mutual benefit. Mutual benefits may include market information or innovation. As Awad and Ghaziri (2004, p. 17) comment ‘Beyond efficiency and productivity, the real benefit of collaboration is innovation.’ The more central the port authority is in this network, the greater are the opportunities for learning. Three key factors are critical for port authorities to integrate knowledge from networks; firstly, there are levels of common knowledge that enable effective communication, including concepts, behavioural norms, language and experience. Secondly integrative efficiency requires organisational routines which foster knowledge sharing through frequent, coordinated activities that are repetitive. Thirdly efficient structures within the port authority help maintain effective and efficient communication to minimise the knowledge loss on integration. Strategising provides opportunities for port authorities to steer the critical path between maintaining their current sources of competitive advantage and developing future resilience through innovation opportunities provided by learning from their trading networks. Port authorities, by developing skills in reading the collective mind and interpreting information available in trading networks, can foster resilience into the future. Given the current risky prognosis for the short-medium term following the financial tsunami, instigating strategies that may lessen those risks may be an option for port authorities.     

Economic policies and seaports: The economic functions of seaports

This paper argues that the economic functions of seaports are to benefit those whose trade passes through them, i.e. through providing increments to consumers' and producers' surpluses. Whilst recent developments in the technologies of seaports (containers, bigger ships, more rapid handling of bulk cargoes) have increased technical efficiency, they have also provided such economies of scale as to reduce some opportunities for competition and, therefore, the probability that cost reductions are actually passed on in this way. For this purpose port costs need to be considered in their entirety, i.e. as generalized transport costs per tonne, comprising money, time and the risks of loss, damage and delay. Such cost reductions will lead to expanded trade in a variety of ways.

This statement of the economic function of seaports is contrasted with views that they should try to increase employment in their locality, or that they should maximize profits.     

海事行政执法的主要风险形式及规避对策

近年来，依法行政的要求越来越凸显其重要地位，随着海事管理工作不断发展，海事部门的执法风险也越来越大。如何正确对待海事执法风险，减少行政责任追究，避免引发社会矛盾和问题，已成为新形势下海事执法人员在履行职责中必须研究解决的重要课题。文中在总结海事执法存在的主要风险和环节基础上，具体分析海事执法风险产生的原因，并提出了规避执法风险的相关对策。     

3600TEU集装箱船建造方案设计

集装箱船特点是线型变化大、精度要求高,相对于其他常规船型,建造难度较大.针对造船领域集装箱船建造方案策划所需考虑的多种因素,进行研究探讨,以3600 TEU集装箱船为例,介绍集装箱船建造方案策划的各项举措,保障项目成功实施.     

An efficient FE computation for predicting welding induced buckling in production of ship panel structure

In a Thermal-Elastic-Plastic (TEP) FE analysis to investigate welding induced buckling of large thin plate welded structure such as ship panel, it will be extremely difficult to converge computation and obtain the results when the material and geometrical non-linear behaviors are both considered. In this study, an efficient FE computation which is an elastic FE analysis based on inherent deformation method, is proposed to predict welding induced buckling with employing large deformation theory, and an application in ship panel production is carried out. The proposed FE computation is implemented with two steps:(1) The typical weld joint (fillet weld) existing in considered ship panel structure is conducted with sequential welding using actual welding condition, and welding angular distortion after completely cooling down is measured. A TEP FE analysis with solid elements model is carried out to predict the welding angular distortion, which is validated by comparing with experimental results. Then, inherent deformations in this examined fillet welded joint are evaluated as a loading for the subsequent elastic FE analysis. Also, the simultaneous welding to assemble this fillet welded joint is numerically considered and its inherent deformations are evaluated.(2) To predict the welding induced buckling in the production of ship panel structure, a shell element model of considered ship panel is then employed for elastic FE analysis, in which inherent deformation evaluated beforehand is applied and large deformation is considered. The computed results obviously show welding induced buckling in the considered ship panel structure after welding. With its instability and difficulty for straightening, welding induced buckling prefers to be avoided whenever it is possible.     

宽带QAM波形解调的关键技术研究

QAM调制是一种频谱效率很高的数字调制方式,在诸如数字微波通信及卫星通信等领域被广泛应用。但由于信道的影响,在接收端对其进行解调非常困难。在介绍QAM调制解调原理的基础上,分析了宽带QAM波形解调时需要考虑的问题,并对其中涉及的定时同步、载波恢复以及均衡等关键技术做了详细的分析和研究。