Implementing the street-turn strategy by an optimization model

The street-turn option represents a major strategy for the profitability of shipping companies supplying container-based transportation. This option consists in the distribution of trucks delivering loaded containers to import customers, the subsequent allocation of empty containers to export customers and the final dispatch of loaded containers to departure ports. However, the determination of truck routes is a time-consuming activity for shipping companies, because available information can suddenly change while they are making their decisions. In this paper we aim to propose a decision support tool to quickly determine truck routes and implement the street-turn strategy. This tool is based on an optimization model determining the allocation of empty containers between customers and defining truck routes in a post-optimization phase. We compare routes resulting from the proposed model to the decisions of a real shipping company. Early results indicate that this approach represents a promising support for shipping companies in dealing with street-turns. It can significantly reduce distances travelled by trucks and times requested to determine routes.     

海事系统60 m级巡逻船总体设计

介绍交通部海事局60 m级巡逻船的主尺度、总体性能、总布置、主要设计特点及主要论证过程。     

KZW-4G型空重车调整装置常见故障分析

分析了KZW4G型空重车调整装置在运用中的常见故障及其产生的原因，并提出了防范措施及改进建议。     

环境监控中心联网方案探讨

介绍并分析了"监控现场一点多传"、"监控中心联网转发"和"通信网关中转分发"三种联网技术方案,其中"监控现场一点多传"技术上难以实现;而"监控中心联网转发"对数据传输可靠性难以保障;"通信网关中转分发"的技术方案可以在系统内部自行实现,从管理层面上减少了环节和层次,更有效率;但必须保证通信网关24小时正常运行.     

BP神经网络在北京道路安全评价中的应用

通过建立北京城市道路交通安全的分析与评价综合体系,采用BP神经网络法对北京的城市道路交通安全水平进行评价。通过对交通安全的状况、交通安全水平与经济发展关系、机动车保有量、人口及构成等因素的客观判断和预测,提出减少交通事故的合理化建议,并通过应用实例分析,说明该方法具有较强的可行性和可靠性。     

船舶营运风险评估及决策问题探讨

船舶造价昂贵巨大,营运时存在着各种风险。风险一旦成为事故,无论是经济效益还是社会效益的后果都十分严重。对此,我国相关研究却和国际水平相去甚远,因此加快我国对船舶营运风险的研究十分重要。本文将数据包络分析法应用于船舶营运风险评估之中,有现实意义。     

赣龙铁路工程景观评价

拟采用景观敏感度、景观阈值等指标,结合赣龙铁路工程在开发及运营过程中,对赣龙铁路沿线景观可能产生的不利和潜在的影响进行分析,提出相应的景观恢复措施和建议。     

Cost assessment for abyssal seafloor waste isolation

We develop an integrated model for estimating the internal cost of abyssal seafloor waste isolation. The model captures the major economic, engineering, geographic and social factors that influence the management cost for sewage sludge and municipal incinerator ash. Considering five representative metropolitan areas and five proposed abyssal study sites, we apply this model to produce cost estimates for four deep-ocean waste delivery system concepts. The results show that the unit cost depends primarily on regional waste volume, the marine delivery system and transportation distance. Based on available data, the abyssal ocean option may be competitive with present land-based disposal costs in New York City. The option is less competitive in other metropolitan areas.     

振动压实中的次谐波振动与混沌

建立了一种土壤非线性力学模型,可以反映土壤弹塑性变形和振动轮跳振等不同压实阶段特点。数值仿真表明,土壤弹塑性变形阶段,系统做周期运动,振动轮起跳后产生次谐波分量,减小阻尼会使谐波分量增加,在一定条件下出现分岔并引发混沌。对研究压实作业中如何产生混沌运动和避免振动轮跳振提供了理论依据。     

超声多波检测自动定量确定列车车轴的裂纹

应用工程多波地震勘探的理论和方法,使用高频DC4型多波检测仪和单分量、三分量换能器,在有裂纹实物车轴模型上进行了多波观测试验,探索出了一套适用于检测列车车轴裂纹的新方法:超声换能器网阵自动定量多波检测法。用研制成功的多波检测计算机三维成像软件系统对观测数据进行处理,其成像结果与已知模型基本相符。该检测法为今后金属无损探伤中对损伤位置、几何形状及尺度等参数的确定开辟了新的方法,有着广阔的应用前景。