基于数据融合的公交客流规模测算方法

公交客流规模测算往往存在调查成本受限和准确度要求较高的矛盾.提出基于公交IC卡历史数据与人工补充调查数据的数据融合测算方法,以准确推算公交客流规模.首先根据公交线路的基本属性,采用聚类分析方法划分线路类型,从每一类中选择具有代表性的线路.基于IC卡数据分析公交客流时变特征,运用有序样本聚类Fisher算法将线路小时刷卡量进行聚类分析.划分刷卡量相似时段,进而采用优化方法确定调查抽样率,确定相应的调查车辆进行人工补充调查,最终经过数据融合计算获得公交客流规模.基于上海市某辖区IC卡数据进行案例分析,测算得到三类公交线路的日均客流量.     

试漏技术在自动变速器生产中的应用

日趋激烈的市场竞争对自动变速器的质量水平提出越来越高的要求。而当前自动变速器市场问题主要集中在异响、漏油及振动噪声三大问题。文章通过从试漏原理以及关键参数设定等方面,对自动变速器生产过程中的试漏检测进行分析。     

深圳前湾围海工程分期开发的优化决策

围海开发是一项投资大、涉及面广、影响因素复杂的工程,开发的目标是在围区土地开发利用规划的前提下,取得最大的综合开发效益.为达到这一目标,必须对围海工程进行规划和经济评价,制定出合理可行的决策方案.     

天津富民桥锚碇及箱梁过渡段构造施工

天津富民桥主桥为单塔空间索面自锚式悬索桥结构,介绍该桥主跨自锚式锚碇、边跨重力式锚碇及钢-混凝土过渡段的施工特点以及根据现场实际情况采取的有效措施.     

丰田燃料电池汽车Mirai技术分析

燃料电池汽车因具有零排放、续驶里程长、燃料加注快和噪声低等优势,引起了国内外汽车产商的广泛关注,将燃料电池新能源汽车作为研发的重点,并推出了一些量产的燃料电池汽车。基于丰田Mirai燃料电池汽车,对其技术原理和核心总成部件进行了综述分析,并对燃料电池汽车的发展方向和关键技术问题进行了思考和建议,为读者提供了有益的参考和借鉴。     

Experimental and numerical study of containership responses in severe head seas

An accurate determination of the global load effects in a ship is vital for the design of the vessel. This paper addresses an experimental and numerical study of containership responses in severe head seas. Experimental results were obtained using a flexible model of a containership of newer design. The experiments showed that, taking hull flexibility into account, the fourth and sixth harmonic of the vertical bending moments had a maximum value of between 25% and 50% of the first harmonic. We also demonstrated that hull flexibility can increase the vertical bending moment by up to 35% in sea states relevant for design. Comparisons of moments found experimentally with results from a nonlinear hydroelastic strip theory method showed that the effect of nonlinearities on the rigid body moments was slightly over-predicted in the aft body. The method also tends to over-predict the increase of the bending moments due to hull flexibility. In general however, the numerical results compared reasonably well with the experimental ones.     

道路交通事故紧急救援保障体系与技术支持

我国汽车保有量仅占全球汽车保有量的3%,而每年死于交通事故的人数约占全球死于交通事故人数的15%20%,尤其交通事故致死率是日本等国家的1020倍。本文就此现象进行基本原因的分析,并着重对交通事故紧急救援保障体系与技术支持问题进行探讨。     

Numerical and experimental investigations into the application of response conditioned waves for long-term nonlinear analyses

The coefficient of contribution method, in which the extreme response is determined by considering only the few most important sea states, is an efficient way to do nonlinear long-term load analyses. To furthermore efficiently find the nonlinear short-term probability distributions of the vessel responses in these sea states, response conditioned wave methods can be used. Several researchers have studied the accuracy of response conditioned wave methods for this purpose. However, further investigations are necessary before these can become established tools. In this paper we investigate the accuracy by comparing the short-term probability distributions obtained from random irregular waves with those from response conditioned waves. We furthermore show how response conditioned wave methods can be fitted into a long-term response analysis. The numerical and experimental investigations were performed using a container vessel with a length between perpendiculars of 281 m. Numerical simulations were done with a nonlinear hydroelastic time domain code. Experiments were carried out with a flexible model of the vessel in the towing tank at the Marine Technology Centre in Trondheim. The focus was on the probability distributions of the midship vertical hogging bending moments in the sea states contributing most to the hogging moments with a mean return period of 20 years and 10 000 years. We found that the response conditioned wave methods can very efficiently be used to accurately determine the nonlinear short-term probability distributions for rigid hulls, but either accuracy or efficiency is to a large effect lost for flexible hulls, when slamming induced whipping responses are accounted for.     

网络布线系统设计与实践

详细描述网络布线系统设计中网络布线系统的结构选型;网络布线系统的标准、产品的选型;电缆的选择以及网络系统的防雷措施,这些设计原则已应用在宜昌市建设工程交易中心信息发布等网络布线系统中,效果甚好.