The distinction between commercial and non-commercial bus services in Germany: Given by nature?

German public transport services by bus are characterized by a regulatory framework that distinguishes between commercial and non-commercial services. Contrary to the apparent views of legislators, this paper shows that costs and revenues are not the only parameters determining whether or not operators are able to provide services in a commercially viable way.Apart from the local characteristics of the specific service, we show that the classification of services as commercial versus non-commercial is determined in large part by the public transport authorities that set minimum quality standards to be provided by operators. Our analysis shows that the authorities awarding the contracts in some cases affect market organization significantly depending on how they make use of this power. Furthermore, market organization differs substantially with respect to the awarding structure and the contractual relationships, thus creating a challenge for operators and authorities in an embryonic market.     

基于AVR单片机的PR自动切换装置

本文介绍了一种以AVR系列单片机ATmega16L为核心,采用霍尔电压传感器将二次测交流高压转换为直流低压的PT自动切换装置,说明了它的硬件设计和软件设计.     

KYN28-12电压柜PT故障分析和处理

针对在6～35 KV的中性点非有效接地系统中可能会产生铁磁谐振现象这一问题,KYN28中置柜通过改进柜体机械结构,采用加装零序电压互感器并在其二次侧加装微机消谐装置的方法,有效地消除和抑制了铁磁谐振现象的产生.     

KYN28-12电压柜PT故障分析和处理

针对在6～35 kV的中性点非有效接地系统中可能会产生铁磁谐振现象这一问题,KYN28中置柜通过改进柜体机械结构,采用加装零序电压互感器并在其二次侧加装微机消谐装置的方法,有效地消除和抑制了铁磁谐振现象的产生。     

电磁型互感器原理差异性分析与应用问题浅论

本文针对生产现场对于电磁型互感器认识上的误区,对电力系统中广泛应用的CT与PT两种互感器的工作原理进行分析比较,从理论层面探讨两者之间的区别与联系。在此基础上,对现场中遇到的一些应用问题予以讨论。     

一种新的汽车前照灯驱动电路设计

LED作为一种新型照明光源,具有发光效率高、寿命长、显色性好、绿色环保、不易破损且易于进行数字控制等优点。采用PT4107芯片设计的LED汽车前照灯驱动电路,解决了车用电压不稳定的问题,电路具有输出电流稳定、精度高、驱动器效率高的特点。     

基于微波感应式的LED灯在地下车库的应用

LED光源以其高亮度低能耗的特点,广泛使用于办公大厦中。本文提出将LED光源同微波探测器结合,构成智能照明控制系统,将之应用于车库中,有效降低建筑物照明能耗,实现节能减排目的。通过某大厦的改造,证明了此方法的有效性和经济性。     

Re-evaluating the association between housing wealth and aggregate consumption: New evidence from Sweden

This paper extends the VECM cointegration model and PT (permanent-transitory) variance decomposition framework proposed by Lettau and Ludvigson [Lettau, M., Ludvigson, S.C., 2004. Understanding trend and cycle in asset values: reevaluating the wealth effect on consumption. American Economic Review 94 (1), 276–299.] and applies them to Swedish data from 1980q1 to 2004q4. There is strong statistical evidence that the long run movements of aggregate consumption, disposable income, housing wealth, and financial wealth are tied together. However, the evidence also suggests that short run variations in the Swedish housing market are largely dissociated with consumer spending. Meanwhile, it is shown that the strength of the linkage between consumption and housing wealth is not sensitive to different model specifications and various measures of key variables.     

排球项目移动测试、训练智能仪器的研制

多年来排球运动员反应移动训练、测试用秒表手工计时。移动测试、训练智能仪器的研制填补了没有仪器计时的空白。运用基于ARM9和WINCE系统的智能仪器能准确测量运动员反应移动能力、减少人为误差。为选拔高水平运动员和使反应移动训练更加科学化和系统化。     

简易无线电遥控系统

文中的无线电遥控系统是基于高频锁相环NE564设计的多控制对象系统.使用NE564设计发射机和接收机,采用FM调制脉冲信号和FSK方法解调,以8051单片机编码和解码,通过PT2262芯片将接口并串行转换,使用PT2272芯片将解调到的串行数据转换为并行数据,实现对八个目标的控制,并且配合LCD显示.系统结构简单小巧,有友好的人机界面,性能稳定,功耗低,控制距离远.