基于RS和GIS的额济纳旗土地利用变化研究

基于Landsat卫星遥感数据,运用GIS方法,对额济纳旗1986-2000年以土地利用类型为表征的时空变化特征进行了研究.结果表明:14年来该区草地、林地、水域、耕地面积减少,居民工矿建设用地和未利用土地面积显著增加,土地利用动态转化过程以草地转化为未利用土地、林地转化为草地和未利用土地逆转为草地为主要特征,全旗土地利用的空间位置转换面积大于其数量变化.而气候变化和人类活动是导致研究区土地利用变化的主要因素.     

一种新的缩短RS码迭代译码方案

为了在EPON中应用GF(256)标准RS码对信息帧长大于255位的信息流进行编码,并提高RS码的编码增益,提出了一种新的缩短RS码的编译码方案。该方案通过两个缩短RS码的交叠编码和互相迭代译码,可以提高编译码增益。RS码BM硬判决译码和chase软判决译码的计算机仿真表明,该方案对缩短RS码的软硬判决译码性能都有明显提高。     

JTIDS传输符号产生模块的FPGA设计

根据公开的关于Link16数据链的信息标准并结合对战术数据链的具体要求,设计了一种JTIDS传输符号产生模块,该模块包含RS编码、交织、CCSK软扩频、CCSK码字加密等若干子模块。首先介绍了Link16数据链传输符号的产生原理,对其各个子处理模块进行了设计并提出了硬件实现方案,然后在Quartus II环境下选择Cyclone II系列的EP2C8Q208C8 FPGA芯片进行了JTIDS传输符号产生模块的系统级综合与仿真,并在该芯片的开发板上进行了验证,硬件成品可用于JTIDS终端功能测试与评估等多种场合。     

Tourism and employment in the Gambia

In addition to providing formal wage labor in hotels, airports, and the service infrastructure, tourism is said to provide possibilities for independent indigenous enterprise in handicrafts, entertainment, transport, through which the Gambians may, in effect, economically “lift themselves up by their bootstraps.” Such is the theory. This paper analyzes the actual employment possibilities in The Gambia provided by its recent tourism investment. From the findings of an economic survey the author concludes that hopes of economic development being catalyzed by tourism are unfounded and misleading. This conclusion is supported by a structural analysis and a characterization of the tourist industry in The Gambia by an investigation into the economic forces at work in the country, and by direct observations made by informants and the author concerning the impact tourism has made in spheres non-economic: the moral, the social, and the family.     

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.     

The tourist guide: The origins,structure and dynamics of a role

The two lines of origin of the modern tourist guide are the pathfinder and the mentor. These are the antecedents, respectively, of the leadership and the mediatory spheres in the guide's role. Since each has an inner and an outer directed aspect, four major components of the role are distinguished: the instrumental, social, interactionary, and communicative. The dynamics of development of the role from the Original to the Professional Guide is represented as a transition of emphasis from the instrumental to the communicative component. Aside from this main line of development, two new role types have differentiated: the Animator and the Tour-leader, emphasizing, respectively, the social and the interactionary components. The Original Guide's function is to produce attractions in the marginal regions of the ecological tourist system, while that of the Professional Guide is to reproduce the attractions in the central regions of the system.     

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。     

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.     

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。