鱼雷防御技术—反鱼雷鱼雷体系发展思考

反鱼雷鱼雷是世界主要鱼雷研制国家积极开发的新型主动防御武器。由于其处于发展阶段,各个国家的技术道路有所不同,在多层防御体系中给出的反鱼雷鱼雷使用阶段和措施也不尽相同。本文针对反鱼雷鱼雷的实际需求,给出了反鱼雷鱼雷分类与拦截区域划分、末端拦截的反鱼雷鱼雷作战层次、反鱼雷鱼雷发展阶段、舰基末端拦截反鱼雷鱼雷的主要性能需求等概念,对明确反鱼雷鱼雷的作战使用、层次划分和促进反鱼雷鱼雷的发展有参考价值。     

Cycle Network Planning: Towards a Holistic Approach Using Temporal Topology

ABSTRACT

Current cycle-network planning (CNP) at the local level tends to be dominated by a subjective-pragmatic approach in which it is only possible to consider a limited number of route alignment possibilities and development-sequencing scenarios. Although this method may produce acceptable results, it may also be true that the final design could be improved – and the construction efficiency could be enhanced – by a more comprehensive review of the available options in relation to the objectives of the intervention. Such objectives may include accident reduction, modal shift in favour of cycling, health benefits or strategic expansion of a network. This article presents work undertaken to demonstrate a holistic approach to CNP, based on a logically defined spatio-temporal model and allowing some semi-automated multiobjective optimization of network designs in a GIS-based decision-support system. The model is introduced briefly before a case study applying this model to development of a cycle network in a small town in northeast England is described. The results obtained from this case study and the implications of this research for cycle network planners are discussed.     

内河船舶极限强度计算的逐步破坏法程序设计

在船舶设计与强度评估中,为更加真实地了解船体结构的安全极限,要求计算船体梁的极限强度。逐步破坏法由于其计算效率高,结果比较可靠,被广泛运用于大型海船设计,但在内河船舶设计规范中,至今尚无有关极限强度的条款。通过非线性有限元程序计算得到加筋板单元平均应力应变关系,并与Rahman法、CSR法以及ISUM方法计算得到的应力应变关系曲线进行对比,以验证其可靠性。然后,按照一定的规律建立符合内河船舶构造的加筋板单元应力应变关系数据库,并编写逐步破坏法计算程序,在计算过程中,其能根据加筋板单元尺寸自动选取对应的关系曲线;对参数超出数据库的情况,则通过插值实现。     

Selfishness and altruism in the distribution of travel time and income

Most economic models assume that individuals act out their preferences based on self-interest alone. However, there have also been other paradigms in economics that aim to capture aspects of behavior that include fairness, reciprocity, and altruism. In this study we empirically examine preferences of travel time and income distributions with and without the respondent knowing their own position in each distribution. The data comes from a Stated Preference experiment where subjects were presented paired alternative distributions of travel time and income. The alternatives require a tradeoff between distributional concerns and the respondent’s own position. Choices also do not penalize or reward any particular choice. Overall, choices show individuals are willing forgo alternatives where they would be individually well off in the interest of distributional concerns in both the travel time and income cases. Exclusively self-interested choices are seen more in the income questions, where nearly 25 % of respondents express such preferences, than in the travel time case, where only 5 % of respondents make such choices. The results also suggest that respondents prioritize their own position differently relative to regional distributions of travel time and income. Estimated choice models show that when it comes to travel time, individuals are more concerned with societal average travel time followed by the standard deviation in the region and finally their own travel time, while in the case of income they are more concerned with their own income, followed by a desire for more variability, and finally increasing the minimum income in their region. When individuals do not know their fate after a policy change that affects regional travel time, their choices appear to be mainly motivated by risk averse behavior and aim to reduce variability in outcomes. On the other hand, in the income context, the expected value appears to drive choices. In all cases, population-wide tastes are also estimated and reported.     

完善车辆安全标准，建立营运车辆安全准入制度

完善营运车辆安全性标准、建立营运车辆安全准入制度,可提高营运车辆的整体安全性,减少群死群伤重大交通事故的发生率。通过对几起特大群死群伤道路交通事故车辆结构强度进行研究分析,以期从源头上提高营运车辆的结构安全性,无论对营运车辆生产商、管理部门还是构建和谐安全社会,都具有很强的现实意义。     

基于差分进化算法的区域OD矩阵反推分析

利用极大熵模型反推OD分布矩阵,引入差分进化算法来求解极大熵模型。采用差分进化算法,与传统方法相比,能够提高求解极大熵模型的速度与精度,从而提高OD矩阵推算的准确度。最后,利用简单实例分析该使用方法的有效性。     

基于多源大数据融合分析的公交优惠政策评估

为科学评估公交优惠政策的实施效果,采用公交客流量、财政补贴等统计数据与公交IC卡数据、公交车GPS数据等多源大数据相结合的方法,对免费换乘和老年人优惠政策带来的公交出行行为进行分析.研究发现,免费换乘政策实施初期有效促进了换乘行为,但其作用逐步减弱,在继续推行免费换乘政策的同时,需要大力推进大中运量公交建设并优化调整常规公交线网.老年人享受了较大比例的财政补贴,公交出行频次和换乘行为更加频繁,无效出行较多,出行时间和乘坐公交线路均比较集中,与通勤出行存在重叠,老年人和年轻人在一定程度上存在对有限公交资源的抢夺,老年人优惠政策需要进行优化调整.分析结果可以为后续公交优惠政策调整提供一定的决策依据.     

材料性能数据管理平台开发及应用

材料性能参数是设计研发阶段产品设计仿真的基础,也是产品最终使用性能的保障。基于此,文章通过对国内外材料数据管理系统及发展趋势研究,基于目前流行的B/S架构,采用MVC分层设计模式,进行了材料数据发布、分析、应用和废止的全生命周期管理平台系统的开发,能够支持材料数据管理、对比分析,并能输出分析软件直接使用的材料卡片,实现同工程分析的无缝对接。材料性能数据管理平台在材料数据管理和应用层面具有很好的实用价值。     

车用乙醇汽油金属腐蚀抑制剂的研究

针对乙醇汽油对金属腐蚀性加剧的问题,研究了新的金属腐蚀抑制剂,其作用机理是各种成分协同作用,在金属的表面形成有效的保护膜,抑制由于水的存在导致的酸腐蚀和电化学腐蚀。在金属腐蚀抑制剂加量200 m g/L时,对黄铜缓蚀率为93.7%;对紫铜缓蚀率为91.9%;对铝缓蚀率为90.0%;对20钢缓蚀率为78.5%;且性能优于美国专利配方。