微型计算机在表面粗糙度参数计算中的应用

本文论述了微型计算机解决表面粗糙度参数计算问题,推导出表面粗糙度参数计算算法,并用BASIC语言在APPLE-Ⅱ及PC-1500微型计算机上成功地完成了表面粗糙度参数计算程序。     

江苏省水上ETC建设经济效益评价探讨

文章针对江苏省水上ETC系统建设,提出水运交通项目经济评价指标体系,并以江阴船闸为例进行计算分析,给出项目建成前后的效益对比,为系统正式实施提供部署方案和参考。     

三峡船闸试通航半年简析

三峡船闸试通航半年有关数据表明,船闸设备设施技术状况良好,船闸运行总体表现为较高水平,船舶待闸积压是试通航阶段和当前航运市场条件下难以避免的现象,需要采用综合措施逐步解决。本文对三峡船闸提高通过能力和建立疏通机制提出了看法。     

Development of six sigma concurrent parameter and tolerance design method based on response surface methodology

Using Response Surface Methodology (RSM), an optimizing model of concurrent parameter and tolerance design is proposed where response mean equals its target in the target being best. The optimizing function of the model is the sum of quality loss and tolerance cost subjecting to the variance confidence region of which six sigma capability can be assured. An example is illustrated in order to compare the differences between the developed model and the parameter design with minimum variance. The results show that the proposed method not only achieves robustness, but also greatly reduces cast. The objectives of high quality and low cost of product and process can be achieved simultaneously by the application of six sigma concurrent parameter and tolerance design.     

摊铺机夯锤轴承座的公差与配合分析及改进

针对摊铺机熨平板夯锤总成中的双孔轴承座装配后出现轴承卡滞、轴抱死等现象,分析了轴承座孔、轴与调心滚子轴承的配合尺寸,计算可能出现的径向游隙,指出由其带来的不合理变化及产品质量问题,提出合理的公差尺寸配合及制作工艺。     

Timetable optimization models and methods for minimizing passenger waiting time at public transit terminals

This paper focuses on developing mathematical optimization models for the train timetabling problem with respect to dynamic travel demand and capacity constraints. The train scheduling models presented in this paper aim to minimize passenger waiting times at public transit terminals. Linear and non-linear formulations of the problem are presented. The non-linear formulation is then improved through introducing service frequency variables. Heuristic rules are suggested and embedded in the improved non-linear formulation to reduce the computational time effort needed to find the upper bound. The effectiveness of the proposed train timetabling models is illustrated through the application to an underground urban rail line in the city of Tehran. The results demonstrate the effectiveness of the proposed demand-oriented train timetabling models, in terms of decreasing passenger waiting times. Compared to the baseline and regular timetables, total waiting time is reduced by 6.36% and 10.55% respectively, through the proposed mathematical optimization models.     

DH36钢趾端焊接接头低温疲劳试验研究

常温S-N曲线无法满足极地低温环境下船海结构疲劳设计的需要,开展了-60℃条件下的船用DH36钢焊接接头低温疲劳强度试验研究。根据国标准设计DH36钢趾端焊接接头的疲劳标准试件,将试件放置在低温箱内采用热点应力方法进行疲劳热点应力测试,并与有限元计算结果进行对比分析,验证了试验测量的可靠性。试验共测量了两级应力范围水平,每级应力范围水平测量14个试件,基于测得的热点应力范围及疲劳寿命,利用单侧容限系数法得到了不同存活率下的p-S-N曲线,结果表明,低温条件下疲劳寿命符合对数正态分布,低温疲劳寿命高于常温疲劳寿命。     

汽车零部件精度设计中零形位公差的应用探讨

结合实例对零形位公差进行了较为详细的论述,并针对零形位公差在不同情况下应用所产生的一些难以理解的问题进行了分析与比较,以求在汽车零部件精度设计中更加灵活、更加合理地运用．     

全站仪坐标导线的坐标转换法平差及应用

根据线路测量的特点,对全站仪坐标导线计算进行研究。提出了一种利用坐标转换原理直接对全站仪所测得的坐标进行平差计算的方法。通过实例证明,该方法具有计算简单、快速、精度高等优点。同时,根据该原理,给出了测站坐标差限值,从而实现了全站仪坐标导线的现场检核。     

计算机辅助公差设计发展模式分析

简要阐述了计算机辅助公差设计的基本模式,论述了这些模式的背景或原理,提出了模式间关系的看法。