车身焊接修复过程中影响焊接质量的因素

随着科技日益发展,人们的生活水平越来越好。汽车逐步成为家庭的出行的必备工具。我们中国是人口大国,汽车的保有量逐年上升,伴随车辆的不断增多,汽车发生的碰撞事故也随之增多。而对于严重碰撞损伤的车辆,车身修复过程中的焊接质量,直接影响着维修后车辆的安全系数。     

浅谈质量体系内部审核采用成熟度评价的必要性

质量管理体系内审是组织进行质量体系管理自我完善的重要手段之一,一直以来通常采用符合性评价的方式,评价结束给的评价结论一般是定性的,如符合、基本符合和有效、基本有效;无法用一个量化的数据真实反映组织质量管理体系整体运行的成熟度。那么如何开发一套质量体系评价管理方法,采用量化的数据进行质量管理体系成熟度评价,全面掌握组织质量体系运行成熟度,针对性进行持续改进就尤为必要了。     

浅谈倒车影像系统图像质量评价

倒车影像系统通过车辆尾部的摄像头提供实时的影像,结合倒车轨迹路径描绘成的辅助线,辅助驾驶员完成车辆停放。该功能近几年被广泛应用于车载辅助驾驶安全领域,现市面上有多种倒车影像系统方案,但各方案图像质量存在参差不齐的情况,本文对倒车影像图像质量如何评价,并结合实际用车时的应用场景进行概述。     

探究柴油机装配过程的质量控制

对柴油机进行装配是制造柴油机过程中最为关键也是最后一个工作内容,柴油机能否保证自身良好的工作性能以及能否具备可观的经济性,很大程度上装配工作的好坏具备决定性,意味着最终结果取决于装配结果,也就要求在装配过程中企业必须对其进行质量控制,确保其产品质量能够符合相应标准。因此,为了提高装配的质量,需要探究装配当中使用的工艺并对其进行分析,在深入了解后提出有关的质量管控方案。本文首先分析在装配过程中所使用的机械工艺,并针对其分析提出有效的质量控制措施,为日后的制作奠定良好的理论基础。     

基于G1法的海外铁路项目风险评价方法研究

为了提高海外铁路项目风险评估和项目管理水平,解决"一带一路"倡议下铁路"走出去"的技术难题,建立了海外铁路项目风险评价指标体系和多级评价模型.首先,根据层次分析法的原理,按照项目风险来源性质的不同,建立了由5个1级指标和15个2级指标组成的海外铁路项目风险评价指标体系;其次,利用G1法对专家关于指标重要程度的排序意见进...     

Some Key Technologies of a New-type CNC Curve Grinding Machine

This paper presented a new-type CNC curve grinding machine, in order to conquer the disadvantages of conventional NC curve grinding machine and improve surface quality, dimensional accuracy and machining efficiency. The new-type grinder adopts some high and new technologies: ① the normal tracing device could make grinding wheel coincide with the normal direction of the machining points in work piece, and improve surface quality and dimensional accuracy; ② the digital image on-line recognition system could monitor machining process and compensate wheel wear in real time; ③ linear motor drive mechanism could realize the exact adjustment of the grinding head digitally and increase the machining efficiency. The math models of normal tracing and circular tolerance zone were presented. The experimental results show that the new-type CNC curve grinding machine equipped with the three devices mentioned above is easy to realize the precision grinding of any complex curve, and improve surface quality, dimensional accuracy and machining efficiency.     

移植TAFE质量管理体系强化高职院校质量管理

通过对TAFE中ISO质量理念和方法的研究,全面深刻了解TAFE质量管理体系。结合我国职业教育质量管理特点,移植TAFE的成功经验,建立完善我国当前的高职质量管理体系,推动高职教育质量建设。     

基于SERVQUAL的网约车服务质量评价研究

随着“互联网+”的广泛应用以及网约车服务模式的合法化,使我国大城市网约车的服务质量问题愈发暴露出来。为提高网约车服务质量,根据SERVQUAL构建了网约车评价指标体系,并通过AHP研究方法和IPA分析分别对网约车服务影响因素和网约车服务评价指标进行了分析,从而提出网约车服务质量控制策略,对网约车服务质量改善具有一定的参考意义。     

Traffic modelling in system boundary expansion of road pavement life cycle assessment

This paper uses a case study of a UK inter-urban road, to explore the impact of extending the system boundary of road pavement life cycle assessment (LCA) to include increased traffic emissions due to delays during maintenance. Some previous studies have attempted this but have been limited to hypothetical scenarios or simplified traffic modelling, with no validation or sensitivity analysis. In this study, micro-simulation modelling of traffic was used to estimate emissions caused by delays at road works, for several traffic management options. The emissions were compared to those created by the maintenance operation, estimated using an LCA model. In this case study, the extra traffic emissions caused by delays at road works are relatively small, compared to those from the maintenance process, except for hydrocarbon emissions. However, they are generally close to, or above, the materiality threshold recommended in PAS2050 for estimating carbon footprints, and reach 5–10% when traffic flow levels are increased (hypothetically) or when traffic management is imposed outside times of lowest traffic flow. It is recommended, therefore, that emissions due to traffic disruption at road works should be included within the system boundary of road pavement LCA and carbon footprint studies and should be considered in developing guidelines for environmental product declarations of road pavement maintenance products and services.     

Simulating the air quality impacts of traffic calming schemes in a dense urban neighborhood

In this study, the effects of isolated traffic calming measures and area-wide calming schemes on air quality in a dense neighborhood were estimated using a combination of microscopic traffic simulation, emission, and dispersion modeling. Results indicated that traffic calming measures did not have as large an effect on nitrogen dioxide (NO₂) concentrations as the effect observed on nitrogen oxide (NO_x) emissions. Changes in emissions resulted in highly disproportional changes in pollutant levels due to daily meteorological conditions, road geometry and orientation with respect to the wind. Average NO₂ levels increased between 0.1% and 10% with respect to the base-case while changes in NO_x emissions varied between 5% and 160%. Moreover, higher wind speeds decreased NO₂ concentrations on both sides of the roadway. Among the traffic calming measures, speed bumps produced the highest increases in NO₂ levels.