Implementing first-in–first-out in the cell transmission model for networks

In traffic assignment models with time-varying flows (dynamic network loading or dynamic traffic assignment), overtaking behaviour is normally not included in the model and, in that case, it is important that the model at least approximates first-in–first-out (FIFO), to prevent deviations from FIFO that are arbitrary or unrealistic or not physically possible. For the cell transmission model (CTM) it has recently been shown that the usual recommended method for preserving FIFO will ensure FIFO for each cell taken separately but does not fully ensure FIFO in the transition between cells and hence does not fully ensure FIFO for sequences of cells or for links or for routes. As a result, deviations from FIFO can easily occur and cumulate along the links or routes. In view of that, we define and analyse three different levels of satisfaction or approximation of FIFO, together with corresponding methods for achieving them. Two of these are existing methods and one is new. We develop, analyse and compare the three methods and the extent to which each of them adheres to FIFO for sequences of cells and links or routes. Also, for two of the methods we present a more detailed algorithm for applying them within the CTM. The paper is concerned with how to implement FIFO in the CTM and not with testing for FIFO or measuring deviations from FIFO.     

Train routing and timetabling problem for heterogeneous train traffic with switchable scheduling rules

This paper proposes a mathematical model for the train routing and timetabling problem that allows a train to occasionally switch to the opposite track when it is not occupied, which we define it as switchable scheduling rule. The layouts of stations are taken into account in the proposed mathematical model to avoid head-on and rear-end collisions in stations. In this paper, train timetable could be scheduled by three different scheduling rules, i.e., no switchable scheduling rule (No-SSR) which allows trains switching track neither at stations and segments, incomplete switchable scheduling rule (In-SSR) which allows trains switching track at stations but not at segments, and complete switchable scheduling rule (Co-SSR) which allows trains switching track both at stations and segments. Numerical experiments are carried out on a small-scale railway corridor and a large-scale railway corridor based on Beijing–Shanghai high-speed railway (HSR) corridor respectively. The results of case studies indicate that Co-SSR outperforms the other two scheduling rules. It is also found that the proposed model can improve train operational efficiency.     

船舶医疗的相关规范要求及标准综述

为了指导船舶设计和开发,研究了船舶医疗的相关公约、规则规定、要求及标准等,归纳了船舶医疗的具体内容,分析了其关联性并重点引述了各文献的显著性细节要求。结论表明,已述的文献满足了常规船型的医疗设计需求,但对于大型的医务船和特殊船舶等,还应依其特殊性进行细节的着重考虑,并根据其特征性进行分析研究和设计。     

基于扩展置信规则库的海盗袭击事件风险预测

为有效应对海盗袭击事件，减少可能产生的损失，本文提出一种新的基于扩展置信规则库 (EBRB)联合优化的海盗袭击事件风险预测模型。通过引入Relief F算法和差分进化算法，从结构和参数两个角度对EBRB系统进行优化，以确保EBRB系统具有最优的参数数量和取值，利用实际海盗事件数据集进行模型验证。结果显示，联合优化的EBRB系统预测结果与实际情况的拟合效果较好，相对于初始的EBRB系统，联合优化EBRB系统将海盗事件的风险预测准确性提高 了60%。此外，与现有其他预测模型对比发现，基于联合优化EBRB系统的预测模型在提高预测准确性方面具有一定的优势。     

协调版共同结构规范对港口工况下散货船的影响分析

协调版共同结构规范（CSR-H）对港口工况下船体梁强度和船体构件局部强度的要求与先前的油船共同结构规范（CSR-OT）基本一致,而相比散货船共同结构规范（CSR-BC）有明显变化。通过对比分析CSR-H和CSR-BC对于港口工况具体要求的差异,并结合实船数据分析,阐述基于CSR-H要求的港口工况对散货船结构设计的影响;并探讨针对符合CSR-H的散货船,如何合理选取船体梁许用静水弯矩值和许用静水剪力值。     

1100TEU船振动和噪音研究分析及方案实施

论述了有关振动和噪音的最新生效的规范规则及其影响,设计院所、船级社和船厂协同对1100TEU小型集装箱船的振动和噪音进行规范研究分析,进行了有限元建模计算分析和船模试验的理论分析论证,并对设计方案和工程践行工艺提出了具有极高使用价值的实施建议,为确保江南造船1100TEU(船号H2538~43)振动噪音考核的重要性能指标均达到了设计目标而按期顺利交船提供了技术支持。     

拱盖法地铁车站施工沉降规律及控制对策研究

为得出适用于上软下硬特殊地质条件下青岛地铁安全开挖方法及地表沉降规律,总结出相应的控制对策,通过数值模拟结合现场实测数据,分别对上断面以左中右导洞均错开12 m平行施工、柔性支撑换作拱盖二次衬砌及下断面开挖3个阶段进行分析。总结出导洞开挖的先后顺序对地表横向、纵向沉降曲线影响的规律,得到了掌子面超前变形范围为12 m、上断面开挖横向影响半径为1.5倍洞径,及上断面开挖和拱盖与柔性支撑的换作是导致沉降的主要原因等结论;根据导致沉降的主要施工步序提出了关键加固对策,并得出了青岛特殊复合地层条件的支护方法和地表沉降经验公式。     

依法治国背景下加强大学生法治教育的思考

党的十八届四中全会通过的《中共中央关于全面推进依法治国若干重大问题的决定》指出,要把法治教育纳入国民教育体系,推动全社会树立法治意识。高等教育是国民教育体系的最高层次,高校是培养高素质人才的重要阵地,大学生是法治中国建设的中坚力量。而目前我国大学生法治信仰缺失,高校法治教育发展滞后,应在现代法治教育中融入优秀传统文化,让法治成为大学生的精神信仰和生活方式,让大学生成为全社会遵纪守法的模范。     

缸内直喷LNG发动机燃烧过程测量分析

将1台直列4缸汽油机改装为缸内直喷LNG发动机,用自行开发的发动机工作过程测量分析系统测量其缸内压力.分析了标定转速和最大扭矩转速下最高燃烧压力、压力升高率、缸内温度的变化,并计算分析了其放热规律.结果表明:与汽油机相比,改装后的天然气发动机燃烧较慢,后燃现象较严重;最大扭矩点的最大压力及最大压力升高率大于标定点;转速...     

应用规则引擎构建舰艇作战决策系统方法研究

针对开发作战决策系统存在的问题,提出了基于规则引擎构建作战决策系统的方法。该方法使用开源Java规则引擎Drools作为决策系统的推理机,使决策规则与其它仿真软件代码分开,显著提高了系统开发效率,降低了系统维护的复杂度。Drools采用面向对象系统增强并优化的Rete算法实现推理机的模式匹配,可满足规则复杂的作战系统对决策时间的要求。实验表明,该方法能很好地完成复杂决策系统的构建。