多尺度地名地址空间区位编码模型研究

针对目前地名地址编码存在的区位信息缺乏、编码粒度较粗、稳定性和可读性较差等问题,本文提出了地名地址编码设计的3个原则：（1）每个地名地址的编码独立且稳定;（2）编码易于实现;（3）编码便于识读。基于地球剖分理论,设计了一种多尺度的地名地址空间区位编码模型,该编码模型以地球剖分网格作为基础单元,建立地名地址空间区位属性与球面网格的映射关系。进一步提出了地名地址空间区位编码方法,该编码是由定位码、层级码和半跨度码组成的一维定长组合码,并且从空间位置、区域范围和空间关系3个方面分析了对空间区位编码的识读方法。最后,以物流行业为例,探讨了地名地址空间区位编码模型的应用思路与前景。结果表明,该模型便于计算机存储与管理,能够为地名地址的网格化管理提供组织与表达基础,对智慧城市建设具有很强的理论和实用价值。     

GPS定位的误差来源与未来发展

GPS定位的精度受到诸多因素的影响,其主要误差来源包括与GPS卫星有关的误差、与信号传播有关的误差、与接受设备有关的误差。GPS的未来发展,一是依赖于1999年底研制成功的新一代BlockⅡF工作卫星,它们将逐步代替目前轨道上的BlockⅡR卫星,其寿命为现有卫星的3倍;二是采用第3个民用频率（L3C）发播不保密的民用信号,民间用户无需解算整周相位模糊值,在大幅缩短观测时间的前提下,能获得厘米级的定位精度,大大提高观测成果的可靠性和工作效率。我国在卫星定位领域已取得突破性进展,“北斗导航定位系统”的建成对我国国民经济建设和国家安全有重要作用。     

利用终端位置时空转移概率预测通讯基站服务用户规模

基站服务用户数的预测对通信基站的空间位置选取、通讯服务带宽的配置优化等有重要作用,并为城市公共安全管理方面中的人群聚集预警与群体事件预防提供辅助决策支持。本文利用海量手机轨迹数据,运用时空转移概率定量化描述城市内不同区域间人群流动的时空特性,结合马尔可夫链和贝叶斯定理,构建手机用户群体在基站间的时空转移概率模型,并以此提出一种城市区域尺度上的基站服务用户数预测方法。利用湖北省某城市长达30 d的手机轨迹数据进行模型训练与预测方法验证,实验结果表明：在时间粒度为60 min时,本文提出的方法对8-22时各时段基站服务用户数预测准确率都大于94.8%;在不同时间粒度下对比本文方法、Castro模型、移动平均法,发现在时间粒度大于20 min时,本文方法预测准确率高于另外两种方法。     

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AN APPROACH TO RETAIL COMMERCE LOCATION OF GUANGZHOU URBAN AREA

Proceeding from the commercial function of Guangzhou urban area, this paper expounds the principles and requirements for choosing commercial location, puts forward the bases to determine the limits of commercial centres. Thirty major commercial centres, in Guangzhou urban area are classified by means of cluster analysis. The function, size, hierarchy and interconnection of commercial centres of different groups are studied. The paper emphatically analyzes the major characteristics and formation factors of the commercial location of Guangzhou urban area. Finally, to counter some problems in existence, some suggestions are put forward in order to improve the commercial location of Guangzhou urban area.     

A STUDY ON RATIONAL LOCATION OF THE COTTON PRODUCTION IN CHINA

Cotton is the leading cash crop in China. The cotton sown area accounts for about 30per cent of the total sown area of all the various cash crops. It is the main material used in the textile industry in China. More than 95per cent of textile materials were cotton during the 1950s; and it still occupies 80per cent at present. There are some problems concerning rational location of cotton production in China. In order to solve the problems existing in civil cotton production and supply, in view of strategy, a number of cotton production bases must be selected and built step by step in a planned way. The location of cotton production should be adjusted progressively in accordance with the existing problems. The existing cotton production regions should be consolidated and improved. The cotton production region of the middle and lower reaches of the Huanghe River should be renewed quichly to make it become the largest stable and high-yield cotton preduction region. In the regions with suitable natural condi     

模糊综合评判模型在隐伏矿定位预测中的应用

对于隐伏矿的定位预测,恰当的描述与处理不精确、非线性的控矿因素信息一直是困扰找矿工作者的难题。模糊数学用隶属函数来刻画元素对集合属于程度的连续过渡性,将经典集合的二值逻辑{0,1}扩展为[0,1]区间内的连续值逻辑。基于以上认识,本文利用模糊数学方法,结合AHP(层次分析法),建立了模糊层次综合评判模型,并用于对个旧矿区阿西寨测区5个异常区的综合评价研究。应用实例表明,该方法有效可行,能够给出合理的总体评价结论。     

HONG KONG DIRECT INVESTMENT IN CHINA＇S MAINLAND： A SPATIAL STUDY WITH SPECIAL REFERENCE TO THE LOCATIONAL BEHAVIOUR OF INVESTORS

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An algorithm for the optimum distribution of a regional seismic network—I

Summary An algorithm for the optimum distribution of any number of regional seismic stations is formulated. The information needed from a given region is the relative distribution of seismic intensity and the travel times of seismic waves used in earthquake location procedure. To define the optimum distribution of a regional network, some generalization of D-planning (minimization of the ellipsoid volume of earthquake location errors) was applied. The D-optimum criterion is generalized for a case where equations describing the process are nonlinear and when the most probable values of the sought parameters (origin time and earthquake focus coordinates) are not known.As an example of the algorithm application, the optimum distribution of seismic stations in the central district of the Lublin Coal Basin in Poland is given.     

闪电定位系统布网方案设计的技术探讨

以闪电定位系统的定位原理和误差分析方法的基础，利用系统布设客观分析软件的自动选站和误差计算功能，比较了以不同方式组成的闪电监测网在一定范围内的定位误差。结果显示，除了系统本身存在的方位和时间误差外，布设子站的数目、几何形状、站距的大小对定位精度的影响均非常明显，与系统采取的定位算法也有很大关系。同时，提出并采取“一子多主，多叉组合”的技术策略，以湖北省为例，对闪电定位系统布网方案设计进行技术探讨。