Donor states and donee states: investigating geographic redistribution of the US federal-aid highway program 1974–2008

In 2009, the US government spent more than $42 billion on the federal-aid highway program. Most of this money was raised from motor vehicle taxes, whose proceeds are deposited in the highway trust fund. Federal motor vehicle user taxes flow into the fund and aid expenditures flow out from it to build and maintain highways and other transportation infrastructure. With so much money at stake it should be no surprise that expenditure decisions are the subject of intense political debate. Chief among these debates is the conflict between donor states, whose residents pay more in highway user taxes than the state receives in federal highway aid and donee states, whose residents pay less in highway user taxes than the state receives in highway aid. While this geographic redistribution has been masked recently by infusions of general fund revenue into the trust fund, the debate nevertheless continues. This paper attempts to understand why some states are donors and others are donees by simultaneously testing four hypotheses about the geographic redistribution of federal highway dollars that relate to a state’s highway need, economic condition, level of urbanization, and representation on the key Congressional oversight committees. The analyses show that redistribution does not favor states with larger highway systems, more highway use, or lower median incomes, all of which are different indicators of need. Instead, states that are less urban and better represented on the four key Congressional committees generally benefit from redistribution. These findings indicate that the user tax revenues are not used in places where they are most needed. Thus they provide little empirical support for any compelling policy argument for continued geographic redistribution of federal highway user tax dollars.     

船舶照明监控系统的设计

随着船舶制造业的不断发展，船舶管理智能化已经成为不可逆转的趋势。该研究是针对船舶照明监控节能设计的一套监控系统。该系统可以通过监控界面对整个船舶的照明状况进行实时监视和统筹管理，并具备了门禁、火灾和液面报警等功能，对船舶进行智能监控。该系统采用施耐德系列的Vijeo-Designer界面开发软件及Twido系列PLC控制实现船舶照明监控及智能报警。此人机界面有界面简单、友好、成本低等优点，且逻辑性强，操作容易，具有很强的使用价值。     

板式工艺吊耳计算及相关问题的探讨

给出板式工艺吊耳头部各危险截面拉应力、吊孔内表面挤压应力的算式,引入算例参数,给出计算结果并比较;对不同算法得到不同结果的原因进行探讨,提出算法和许用应力值的取用建议。     

降低殷瓦自动焊机的故障频率

MO2焊机是LNG船液货舱围护系统建造所使用的一种进口设备.在焊机使用过程中,故障频率较高.通过对焊机故障问题的分析,发现主要原因,并提出改进对策,加以实施.同时,对改造前后设备的驱动系统进行对比,得出故障频率明显降低,从而保证了LNG船液货舱围护系统生产工作的顺利进行.     

杨高路下立交泵站实时监控管理系统的设计与实施

杨高路下立交泵站在10年养护实践中暴露了诸多缺陷,为此实施了技术改造,建立了泵站实时监控管理系统。介绍了系统的网络结构、COMPOBUS总线布线方式和系统PLC控制层与现场设备层的通信。介绍了由人机交流界面菜单组成的实时运行管理系统,以及在上位机组态中利用InTouch与数据库的对接,生成了泵站运行管理拟表。     

“极度深寒”何时唤醒“回暖”

今年上半年,国际造船市场继续延续了去年10月份以来的低迷态势.订单撤销、合同重谈等诸多深层次矛盾日益尖锐,形势严峻程度远远超过了之前的预期.     

土工合成材料防治半刚性基层反射裂缝的机理分析

该文基于3D数值分析方法对半刚性基层裂缝及接缝处加铺筋材的防治反射裂缝的效果进行了研究,分析了土工合成材料防裂夹层的受力特性。研究发现土工合成材料夹层可以缓解裂缝处的应力集中现象,改善加铺层结构的抗拉和抗剪性能。在此基础上对聚酯玻纤布和玻纤格栅两种材料的防反效果进行了对比分析,结果表明聚酯玻纤布的防裂效果明显优于玻纤格栅。研究成果为夹层防裂材料的选取提供了理论依据。     

高压柴油发电机组用于电厂黑启动的实现

本文介绍了高压柴油发电机组用于电厂黑启动的整体方案.它采用的是高压变频器作高压电机的软启动器,减小了发电机容量,节约成本.文中还说明了基于并车控制器、PLC、触摸屏的控制系统构成和控制思路,并给出了调试方案和结果.     

罗兰C系统非时基交叉圆定位方法研究

在分析罗兰C系统非时基交叉圆定位原理基础上,详细推导了罗兰C非时基交叉圆定位算法,并根据试验得到的时差测量结果进行了单台链双曲线定位与非时基交叉圆定位算法比较。结果表明,当几何因子GDOP较好时,交叉圆定位方法与单台链双曲线定位算法的定位结果相差不大,但当GDOP较差时,采用非时基交叉圆定位方法能够明显提高定位精度,采用交叉圆定位方法能够有效解决单台链双曲线定位方法在基线延长线附近定位时存在的＂奇异＂现象,扩展罗兰C系统有效作用距离。     

基于原子动作的BML动作语义标注方法研究

作战管理语言（BattleManagementLanguage,BML）是一种实现指控与仿真系统间无歧义通信的标准语言规范,其目标是从根本上解决指控与仿真系统之间的互操作问题。针对当前作战管理语言命令缺乏语义信息,不能被仿真模型有效理解和执行的问题,提出了动作映射、原子动作标签的概念,设计了一种基于原子动作的动作语义标注方法。实验表明,该方法有效地实现了仿真模型对命令中动作语义的理解。