基于STC单片机电阻筛选测试仪的设计

本文给出了一种以STC12C5408AD超低功耗单片机为控制核心的自动电阻测试仪的设计。电路通过继电器实现量程的自动改变,从而实现对电阻参数的测量。系统采用高精密的电阻作为参考电阻,通过电压比例计算的方法推算出电阻值。利用STC12C5408AD控制测量和计算结果,再加入自校准电路提高测量精度,同时用差压法消除了电源波动对结果的影响。本系统完成了电阻和电位器的测量并相应实现LED实时显示和RS232在上位机上实时显示电位器阻值随旋转角度变化曲线。另外,通过上位机设计电阻值,系统便能在被测电阻中筛选出与之相稳合的电阻元件。     

Directional bias in vacation travel

Vacation travel between regions is usually asymmetrical. This causes a problem when one tries to use a gravity model to forecast inter-regional travel. Although researchers have adopted strategies for coping with this problem, none of these strategies adequately resolve the complication of asymmetrical flows. This paper presents a measure of directional bias that accounts for unequal flows between two regions, and applies it to inter-provincial flows in Canada for the years 1968 to 1978. The directional bias appears to be stable over the period considered, and the index can be easily incorporated into forecasting models. Its use will allow researchers to add greater precision and power to their predictive models.     

Tourism and economic diversification in Hong Kong

Input-output techniques are used to assess the role of tourism in the economic diversification in Hong Kong. It is found that, in comparison with domestic manufacturing, the value-added content and labor productivity of tourism are relatively high, and tourism requires very little energy, not many laborers, moderate amounts of capital and appreciable amounts of skills, all of which are ideal in an environment of rocketing energy costs, rising wages, and fast growth with rapid accumulation of capital and skills. Moreover, the shares of tourism in GDP and total employment have been increasing due to decreasing leakage. On the demand side, the growth of tourist exports is more stable than many major commodity exports partly because tourism is less subject to import protectionism. Tourism is thus considered a prime choice in the current economic diversification of Hong Kong.     

基于RSView32的自动化仓库监控系统报警参数在线设置的实现

以自动化立体仓库的实时监控系统开发为例，阐述了基于RSView32的嵌入式开发语言——VBA对RSView32的应用进行扩展，结合网络技术、数据库技术实现对立体仓库现场数据管理中报警参数在线设置。     

浅谈RS、GIS在绿色GDP评价体系中的应用

如今,经济全球化已成主流,环境问题突出,可持续发展受到各级政府的关注。我国将以绿色GDP核算体系逐步取代现行的GDP核算体系。本文重点探讨如何发挥遥感(RS)、地理信息(GIS)技术的先进性,在绿色GDP评价体系中发挥重要作用。     

基于PLC的立体仓库运行系统

介绍了可编程控制器（PLC）的基本结构及立体仓库的工作流程，论述了用PLC控制自动化立体仓库以达到仓储技术的全面自动化的制作流程及设计思路。     

面向作业的自动化仓库动态信息管理系统研究与实现

针对我国仓库信息管理的现状,阐述了自动化立体仓库的信息结构及其内在联系,并利用Visual C 6.0和数据库技术,开发面向作业的自动化仓库动态信息管理系统,实现了货品入库管理、出库管理、库存管理、拣货包装管理、配送管理、决策管理、查询检索、打印报表八大功能。     

自动穿梭板的设计及应用

设计了一种轨道搬运机器人——自动穿梭板,并利用专家系统对两台自动穿梭板及堆垛机进行优化调度,提高了自动化立体仓库的存储密度和作业效率,并降低设备投资成本。     

基于FPGA的UART设计

串行通信在数字通信及控制系统中有着广泛应用。由于常用UART芯片比较复杂且移植性差,本文介绍一种利用FPGA实现UART的方法,所有功能全部采用VHDL进行描述,将UART的核心功能集成在FPGA上,使整个设计小巧灵活,可移植性强。     

Constructing smooth tests without estimating the eigenpairs of the limiting process

Based on the well known Karhunen–Loève expansion, it can be shown that many omnibus tests lack power against “high frequency” alternatives. The smooth tests of  Neyman (1937) may be employed to circumvent this power deficiency problem. Yet, such tests may be difficult to compute in many applications. In this paper, we propose a more operational approach to constructing smooth tests. This approach hinges on a Fourier representation of the postulated empirical process with known Fourier coefficients, and the proposed test is based on the normalized principal components associated with the covariance matrix of finitely many Fourier coefficients. The proposed test thus needs only standard principal component analysis that can be carried out using most econometric packages. We establish the asymptotic properties of the proposed test and consider two data-driven methods for determining the number of Fourier coefficients in the test statistic. Our simulations show that the proposed tests compare favorably with the conventional smooth tests in finite samples.