Cost savings of using a marketable permit system for regulating light-duty vehicle emissions

In the USA, each individual vehicle is required to meet uniform per-mile emission standards. The uniform standard system does not allow vehicle manufacturers flexibility in achieving overall emission reduction goals for motor vehicles. The system provides manufacturers with little or no incentive to control vehicle emissions beyond what is required. In this paper, an incentive-based marketable permit system is proposed to replace the uniform standard system. Under the marketable permit system, vehicle manufacturers are required to meet corporate average emission standards; they are allowed to buy or sell vehicle emission reduction credits among themselves to meet corporate average standards; and they are allowed to bank vehicle emission reduction credits that are accumulated in earlier years and to use the credits for meeting average standards in later years. It is estimated in this study that relative to the current uniform standard system, the marketable permit system can reduce vehicle emission control costs by $150 to $400 million per year in California, or 13–30% of the costs currently spent on vehicle emission control.     

Recreation vehicles : A perspective

The growth and popularity of recreation vehicles in the United States and other countries has implications for the travel and tourism industry. Owners of these vehicles require no separate lodging facilities while traveling and rarely patronize hotels or motels. They often perceive that they spend less for their vacations by staying at travel parks and campgrounds, but survey results and comparative cost analysis reveal that they spend more than automobile travelers when total fixed and variable costs are taken into account. Recreation vehicle (RV) preferences by income category suggest alternative modes of recreation travel and a vacation life style which has considerable appeal. This “RV life style” is characterized by a strong desire to experience the outdoors and socialize with other campers while still retaining the comforts and conveniences of a familiar domicile. Limiting characteristics include the provincial nature of recreation vehicle travel and the impact of mandatory fuel conservation measures.     

Impacts of Asynchronous Learning Networks on Individual and Group Problem Solving: A Field Experiment

An Asynchronous Learning Network (ALN) is a Computer-Mediated Communication System designed to support "anytime/anywhere" interaction among students and between students and instructors. A field experiment compared groups and individuals solving an ethical case scenario, with and without an ALN, to determine the separate and joint effects of communication medium and teamwork. Dependent variables include quality and length of the reports, and subjective perceptions of learning and satisfaction. The results indicate that that an ALN enhances the quantity and quality of the solutions to an ethical case scenario. The combination of teamwork with ALN-support increases the students' perception of learning. Although the perception of collaborative learning was similar between ALN-supported and unsupported groups, participants in computer-mediated groups reported lower perceptions of discussion quality than participants in manual groups.     

用AUTOLISP实现分马力电机可变尺寸图形的绘制

AUTO LISP 是嵌套在 AUTO CAD 绘图软件包中的一种功能很强的智能语言,可在绘图软件包环境下直接运行,是一种很适合绘制“可变尺寸图形”的方法。本文详细地研究了 AUTO LISP 源程序编制、在系统状态下编辑程序和在 HCAD 状态下绘图等内容。对 AUTO CAD 的开发应用具有重要作用。     

异步电机教学实验数据处理系统

本文介绍异步电机空载、短路、负载实验数据处理的数学方法和软件设计方法步骤,形成了实验教学软件。     

安徽省旅游资源错位现象及相对效率评价

文章引入错位指数对旅游业发展的“资源诅咒”现象进行定量研究,结合旅游资源的相对效率评价,提出安徽省各地区旅游资源的开发建议.研究表明:2005、2010年合肥负向错位指数最大,宣城正向错位指数最大;皖中旅游资源总效率受纯技术效率驱动较大,旅游资源利用集约化程度较高,皖北旅游资源总效率受规模效率驱动较大,旅游资源利用属于粗放型方式;区域旅游资源相对效率除了与旅游资源禀赋相关外,与第二产业生产总值、第三产业生产总值、人均GDP、全社会固定资产投资、互联网宽带用户数、货物进出口总额、住宿和餐饮业营业额等因素也密切相关;根据错位指数与总效率的排名,对各地区未来旅游资源开发提出相应的建议.     

基于ARM和旋转滤波的异步电机故障检测方法的研究

提出了一种基于ARM和Park矢量旋转滤波的异步电机故障检测方法。该方法结合Park矢量旋转滤波和异步电机定转子故障特征,对定子电流信号进行分析,可有效地检测异步电机的故障。并通过实验证明,该检测方法正确可行。     

基于神经网络的无刷直流电机故障诊断和容错控制方法的研究

提出并设计了一种针对无刷直流电机控制器的故障诊断和容错控制方法。该神经网络状态观测器由实际非线性控制系统进行训练,根据实际系统和神经网络观测器输出残差,容错控制系统能够被确定下来。针对系统控制器、电流和速度传感器的故障条件进行了仿真分析,容错控制通过使用补偿控制器实现,保证系统故障条件下的稳定性和性能。结果表明,所提出的方法能有效地定位错误故障和时间,消除干扰并提高系统的鲁棒性。     

浅谈三相变压器的连接组别

三相变压器的联结组是三相变压器的难点问题之一,通过三相变压器绕组的联结,进一步的说明了三相变压器的联结组及其简单的判定方法——时钟序数表示法,最后对标准联结组进行了详细的说明。     

叶片式气动马达定子制作方式的改进

应用绿色机械加工理念,对叶片式气动马达定子的制作方式进行了改进与优化。在不同情况下,通过对铸铁、铸钢和厚壁无缝钢管等不同材料和形式定子毛坯的选用,不仅大幅提高了材料的利用率,而且最大限度地降低了定子的生产成本。