基于改进粒子群优化算法的鲁棒性列车运行图编制方法

以列车优先级、追踪运行间隔时间和连发间隔时间限制为约束条件,以旅客列车的走行公里总数、平均旅行速度、对标准计划的延迟总时间和延迟时间方差,以及货物列车的日车公里总数和日产最6个指标无量纲转化后的合计值最大为综合目标函数,建立列车运行图编制优化模型.为增加列车运行图的鲁棒性,引入虚拟车和缓冲时间槽2个参数,采用改进的粒子群优化算法给出鲁棒性列车运行图编制方法.以5个车站、5列旅客列车和7列货物列车构造模拟环境,采用该方法进行列车运行图编制模拟.结果表明:该方法可铺画出更优的列车运行图,计算效率高;在行车计划受到扰动后,虚拟车和缓冲时间槽释放资源,运行图可以较快地恢复到可接受范围,容错鲁棒性好.     

基于两级温差发电的船舶废热回收试验研究

对于船舶柴油机而言,其所做功的30%都以废热的形式随尾气排放到了大气中。利用温差发电(TEG)技术回收船舶余热进行发电具有极其广阔的发展前景。因此提出了一种利用船舶柴油机尾气废热进行两级温差发电的新型装置。在对两级温差发电系统进行建模后,搭建了两级温差发电装置并进行了测试。理论分析和实验结果表明该装置利用温差发电技术对船舶余热回收是可行的。当热端温度达到473 K时,该温差发电实验装置可输出功率250 W,系统热效率为5.35％,相比单级TEG在相同条件下4.04％的热效率,该系统提高了32％。最后,对系统优化和装置的进一步改进进行了探讨。     

On the use of mathematical programming in the evaluation of transport policies

This paper focuses on the evaluation processes by which decisions regarding transportation alternatives can be assisted. A multidimensional approach usually called multiple criteria decision making is required to represent the complexity of transportation policy and systems.

The multiple criteria decision making techniques can be divided into two groups. The first is based on a ranking scheme approach and the second on a mathematical programming approach.

A multiple objective mathematical programming procedure known as Goal Programming is presented. The authors examined the use of that procedure in real transportation problems.

The results suggest that multiple objective mathematical programming techniques in general do not appear to be appropriate in transportation policy analysis involving mutually exclusive alternatives. Their use can be limited to special cases in the private sector.     

齿条齿轮四杆函数发生机构的运动综合

介绍了用复数法对齿条齿轮四杆函数发生机构进行运动综合的方法。鉴于这种机构的特殊结构,多用于发生单调和非单调函数以及非线性函数。其主要优点是构件数少,且具有最佳的传动性能。     

基于知识管理的网络办公系统的设计和开发

首先介绍了OA的演变过程和知识管理的基本概念,然后根据实际的开发经验提出了知识管理如何应用在OA中的一种框架和实现方法.     

Can environmental awareness explain declining preference for car-based mobility amongst generation Y? A qualitative examination of learn to drive behaviours

Preference for private, motorised transportation grew substantially throughout the global North, during the 20th Century. Through this time rates of licencing, and car ownership, and vehicle kilometres travelled (VKT) rose across age groups. This had a range of environmental and social equity implications, and ignited a priority for investment in road infrastructure. The system of automobility was cemented by lock-in through the assemblage of infrastructure, technologies, policies and behaviours supporting, and frequently requiring, car based mobility. Yet recent evidence has shown that generation Y (18–35 year olds) are practicing mobility in different ways to earlier generations. Stabilising and declining rates of VKT, licencing and vehicle ownership have been identified in a range of industrialised countries. Adopting an interdisciplinary approach, this paper draws from theories of social practice and the theory of planned behaviour, as two traditions to examine what people ‘do’, focusing on the social and the individual respectively. It examines the motivations to learn to drive (LTD), and the preference for driving in New Zealand, a highly car-dependent country, empirically drawing from 51 qualitative interviews. A series of meta-themes are presented and used to explain intended and actual behaviour relating to driving practices. The empirical research finds a diversity of highly nuanced interpretations of LTD, some of which reflect individual characteristics, whilst other interpretations are best understood grounded in a wider societal reading of contemporary trends and meanings. Frequently, justification for learning to drive goes beyond the competency and capacity to drive independently. Implications for policy and planning are detailed.     

第五代集装箱船在黄浦江内掉头

第五代集装箱船来上海港面临的最大困难是在黄浦江内掉头。作者收集了第五代集装箱船的有关资料，结合黄浦江掉头区地理环境、风流影响、拖轮配置及掉头方式、掉头时机选择等。通过计算机模拟试验，经多次拟合，取得了不同条件下组合的操作要令。结合实际操纵，取得成功。本文将理论与实际操作结合，对港内操纵超大型船舶掉头提供了参考依据。     

船型生成

介绍了中国船舶科学研究中心开发的一个船型生成模块及其特点和应用情况。该模块是针对大型集装箱和大方形系数低速船而建立的，但对一般的船型也适用。它利用强大的数据库，不但能生成性能良好的光顺线型，并能对该船型的快速性能作了评估。     

Modelling Pseudocalanus elongatus stage-structured population dynamics embedded in a water column ecosystem model for the northern North Sea

This paper outlines an approach to couple a structured zooplankton population model with state variables for eggs, nauplii, two copepodites stages and adults adapted to Pseudocalanus elongatus into the complex marine ecosystem model ECOHAM2 with 13 state variables resolving the carbon and nitrogen cycle. Different temperature and food scenarios derived from laboratory culture studies were examined to improve the process parameterisation for copepod stage dependent development processes. To study annual cycles under realistic weather and hydrographic conditions, the coupled ecosystem–zooplankton model is applied to a water column in the northern North Sea. The main ecosystem state variables were validated against observed monthly mean values. Then vertical profiles of selected state variables were compared to the physical forcing to study differences between zooplankton as one biomass state variable or partitioned into five population state variables. Simulated generation times are more affected by temperature than food conditions except during the spring phytoplankton bloom. Up to six generations within the annual cycle can be discerned in the simulation.     

双馈风力发电系统低电压穿越控制的分析研究

文章对国内外的风力发电低电压穿越的现状进行了综述,并对主要的低电压穿越方案进行了分析研究,具有一定的参考意义。