Effective method for knock signal denoising in internal combustion engine

Uncontrolled expansion of combustion wave in spark ignited internal combustion engine causes knock effect which seriously degrades efficiency and lifetime of the engine. Thus, accurate knock detection and control are essential for obtaining a desired performance from the engine. Usually, knock sensor is used to detect this phenomenon but it has limited accuracy especially at engine high-speed rotations because of natural vibration and external noises. In this study an effective method based on Non-Local Mean (NLM) algorithm has been proposed to improve the knock detection accuracy. This method is evaluated based on four different indicators and four engine cylinders. The results show 52.9 % improvement in knock detection. Also feasibility of real time execution of this method based on embedded hardware has been studied.     

从“十一五”到“十三五”:轨道交通从“加快发展”到“完善优化”

正战略规划能力强、执行力强是中国模式的一大特色。以轨道交通发展为例,自"十一五"规划中提出"加快发展铁路、城市轨道交通"以来,我国在铁路与城市轨道交通领域取得了举世瞩目的成就:铁路营业里程达到12.1万km,其中高速铁路超过1.9万km(占全球高速铁路的60%);内地已有24个城市开通快速轨道交通运营线路,总长达3010.6 km;同时,在     

宝马轿车控制系统偶发故障的诊断与排除

一辆宝马轿车在维修保养之后,偶尔会出现报警、故障灯亮、加速无力的故障现象,阐述该故障诊断流程,找出故障原因系气门室盖罩变形所致。更换气门室罩盖罩后,车辆恢复正常。     

Origin–destination table disaggregation using biproportional least squares estimation

This paper describes a group of techniques for disaggregating origin–destination tables for travel forecasting that makes explicit use of observed traffic on a network. Five models within the group are presented, each of which uses nonlinear least-squares estimation to obtain row and column factors for splitting trip totals from and to larger geographical areas into smaller ones. The techniques are philosophically similar to Fratar factoring, although the solution method is quite different. The techniques are tested on a full-sized network for Northfield, MN and are found to work effectively.     

Influence of temperature on the tyre rolling resistance

Temperature is a very important factor controlling rolling resistance of road vehicle tyres. There are at least three different temperatures that may be considered as important factors controlling thermal conditions of the rolling tyre. The most common measure of the thermal conditions during tyre rolling is ambient air temperature. The other two are: pavement temperature and “tyre” temperature. Tyre temperature is the most difficult to establish, as temperatures of different parts of rolling tyres differ considerably, thus there is a problem to obtain representative values. In the authors’ opinion, air temperature is the most universal and reliable parameter to measure. The article presents results obtained in the Technical University of Gdańsk during laboratory and road measurements of different car tyres rolling on different pavements. The knowledge of rolling resistance characteristics is important for modelling car dynamics as well as fuel consumption. It is also necessary to establish proper test conditions in the future standardized on-road method of measuring rolling resistance. The results indicate that generally each tyre and pavement combination is influenced by the air temperature in a unique way, but at the same it is possible to propose some general influence factors that may be used to normalize measurements to the standard temperature of 25 °C.     

Wave propagation in head on bonnet impact: Material and design issues

Head on bonnet impact is becoming more and more important in automotive design as regulations on pedestrian safety become more demanding. Despite the relatively low amount of energy involved, these impacts are truly dynamic phenomena as the event duration is comparable with the traveling time of the different wavefronts generated by the impact. In this paper, we show that we can build up a simplified model for the impact based on wave propagation analysis. Using this model, we can analyze head acceleration on existing bonnets or predict it on new ones. Head acceleration in a bonnet impact can thus be estimated over the whole area of the bonnet with a few minutes of CPU.     

259例骨肉瘤细针吸取细胞学检查及病理学分析

目的:对259例骨肉瘤病例的针吸涂片细胞学特点、诊断和鉴别诊断进行分析,探讨细针吸取细胞学(FNAC)对骨肉瘤诊断的准确性及价值。方法:回顾性分析有完整的术前FNAC结果和术后病理组织学诊断的骨肉瘤259例,分别对其FNAC结果和组织学切片诊断进行对照观察。结果:259例标本中,对骨肉瘤诊断的准确率为73%(189/259),并发现骨肉瘤细胞学的七大特征。结论:FNAC检查能提高术前对骨肉瘤的确诊率,是一种简便、准确、创伤小的诊断方法。     

某加热保温箱型钢筋混凝土厌氧发酵罐的结构设计浅析

该文以某垃圾处理厂加热保温箱型厌氧发酵罐的结构设计为例,简要论述了箱型厌氧发酵罐结构设计的方法和设计要点,并根据发酵罐的特点提出几点结构设计建议。     

技能型人才培养方案学习领域的设计与实践

人才培养方案是学校实施人才培养工作的根本性指导文件,反映了学校在人才培养工作上的指导思想和整体思路,人才培养方案学习领域的设计与实践是专业建设能否取得实效的基础性工作和技能型人才培养能否取得效果的根本保证。     

水运经济信息简讯

交通部规范川江及三峡库区滚装运输市场；第三届中外物流企业洽谈会将于2006年举行；CKYH联盟确定2006年战略计划合作范围扩至支线网络；多家公司欲收购铁行渣华南非航线业务；日邮与商船三并有意入股南沙汽车滚装码头；克里帕集团扩大散货船队；天津国际贸易与航运服务中心揭牌；主要港口十月份生产持续增长。[编者按]