用于台风定位的雷达回波拼图方法

本文采用斜轴等距离方位投影作为拼图底图的投影，选择需要的邻近若干部雷达进行拼图，也可以任选区域进行雷达拼图。这种投影底图不但使原来在单部雷达上有效的台风定位方法得以继续使用，而且提出了雷达对台风的探测范围和精度。经９５年业务使用结果表明，对业务工作有一定参考价值。     

地球静止卫星云图象点定位方法之比较

在假定ＧＭＳ－４地球静止卫星所发定位网格数据的精度满足要求的基础上，通过数学原理分析、改变二维插值顺序、比较插值结果与实际分布等手段，对比分析了利用线性和非线性插值方法给每一个象点定位的结果，发现非线性插值所得结果明显优于线性插值，更加符合实际情况。线性插值的误差在经度方向上较小。可以忽略，但是在纬度方向的误差，即经度误差极为明显。在星下点的左上部，误差由东南向西北迅速增大，有相当一部分地区内经度     

Theoretical Error Analysis of the Accuracy of Focal Depth Determination of Near Earthquakes

Focal depth is one of the most difficult seismic parameters to determine accurately in seismology. The focal depths estimated by various methods are uncertain to a considerable degree,which affects the understanding of the source process. The influence of various factors on focal depth is non-linear. The influence of epicentral distance,arrival time residual and velocity model (crust model) on focal depth is analyzed based on travel time formula of near earthquakes in this paper. When wave propagation velocity is constant, the error of focal depth increases with the increase of epicentral distance or the distance to station and the travel time residual. When the travel time residual is constant,the error of focal depth increases with the increase of the epicentral distance and the velocity of seismic wave. The study also shows that the location error perhaps becomes bigger for shallower earthquakes when the velocity is known and the travel time residual is constant. The horizontal error caused by location accuracy increases with the increase of the epicentral distance,the travel time residual and the velocity of seismic waves,thus the error of focal depth will increase with these factors. On the other hand,the errors of focal depth will lead to change of the origin time,therefore resultant outcomes will all change.     

Between the Centre and the Periphery: the development of port trade in Darwin,Australia

Darwin, the capital of the Northern Territory, is a port city located in Australia's Top End and facing Southeast Asia. The distance from Darwin to Australia's main economic centres of Sydney and Melbourne is almost the same as to Singapore. This central geographical location has inspired the development of the Port and the City of Darwin from time to time while being held back by its remoteness, and especially the lack of an efficient railway link to Australia's major southern centres. The Port of Darwin has been redeveloped with the vision of repositioning the City of Darwin as Australia's gateway to Asia which it was expected to achieve with the completion of the transcontinental railway link from Adelaide to Darwin. This paper analyses trade and cargo movements for the Port of Darwin between 2000 and 2009—5 years for each period before and after the availability of intermodal transport—and examines the processes by which transformation of the gateway is actually occurring. The evidence to date, however, suggests that the landbridge development has had little material effect in terms of trans-shipments and throughputs for the Port of Darwin. The volume of container trade and interstate export and import cargo that passes through the port has in fact declined since the availability of the transcontinental railway in 2005.     

Spatio-temporal features and the dynamic mechanism of shopping center expansion in Shanghai

Since the first modern shopping centre was built in the United States in the 1920s, shopping centres have gradually become representative patterns of economic growth and consumerism in the United States, and these patterns are now trending globally. Shopping centres have demonstrated tremendous development potential since their initial entry into China in the 1990s. Shanghai is the most economically prosperous city in China, and the development and evolution of its shopping centres reflect the trend in China's commercial real estate development. Therefore, based on the central-place and agglomeration economy theory, this paper quantitatively measures and analyses the spatial gravity, extending direction, agglomeration characteristics and hierarchical structure of Shanghai's shopping centres using GIS (Geographic Information Systems) and spatial analysis. Moreover, this paper analyses the dynamic mechanism of urban development and its patterns of centripetal and centrifugal movement. The results demonstrate the following. (1) The spatial gravity points are located in the districts of Huangpu, Luwan and Xuhui in the city centre and within the inner ring. In addition, there is a trend to be gradually near the middle ring, exhibiting an obvious tendency from the northeast to the southwest. (2) Shopping centres in Shanghai exhibit a clustered distribution in the centres of urban areas, which form numerous business districts that extend in the same direction. (3) The hot spot analysis is a very effective method for identifying the hierarchy of business circles. (4) Planning by the government is the most important external impetus, and commercial agglomeration is the internal force determining the spatial expansion of shopping centres. Additionally, urban transportation patterns have an obvious influence on the spatial morphology of shopping centres. (5) Over the last two decades, the spatial development of Shanghai's shopping centres has reached a balance between the centripetal and centrifugal forces. In other words, we have not observed a tendency towards suburbanization, which indicates that Shanghai's shopping centres are still in the early stages of development. Therefore, future shopping centres may be primarily located in the stretch or peripheral zones of the city.     

Distance predicting functions and applied location-allocation models.

Distances between demand points and potential sites for implementing facilities are essential inputs to location-allocation models. Computing actual road distances for a given problem can be quite burdensome since it involves digitalizing a network, while approximating these distances by l _p -norms, using for instance a geographical information system, is much easier. We may then wonder how sensitive the solutions of a location-allocation model are to the choice of a particular metric. In this paper, simulations are performed on a lattice of 225 points using the k-median problem. Systematic changes in p and in the orientation of the orthogonal reference axes are used. Results suggest that the solutions of the k-median are rather insensitive to the specification of the l _p -norm. Received: 12 October 1998/Accepted: 17 September 1999     

导航地图情境建模

目前,尽管形形色色的导航地图产品已经成为人们日常出行的必备帮手,但是实用性不强、效率偏低是普遍存在的一种现象,严重降低了人们对地图的信任程度。为此,本文引进情境理论,通过分析其与导航地图之间的联系,指出情境建模在沟通用户、环境与设备之间作为桥梁的重要意义,并将活动从一般情境信息中剥离出来,确定了导航地图情境建模基本原理,从通用情境信息建模和导航活动建模2个方面详细阐述了导航地图情境建模的方式与方法,为后续研究情境推理与表达奠定基础。     

1994年4月的SL9彗星观测

１９９４年４月１２日晨，我们对Ｓ９彗星进行了成功的观测．观测使用云南天文台一米望远镜和加了缩焦器的Ⅱ号ＣＣＤ系统．照相机像素为５１２×５１２，视场约７’×７’．在近两小时的不同时刻的四张照片中，观测到了彗星２１颗碎核中的主要部份及其运动．本文介绍了此次观测情况和资料处理，并给出对ＳＬ９各彗核的位置和亮度的测量结果．     

城市居民住宅区位选择的因子分析

随着我国住房制度的改革 ,城市居民个人消费成为我国房地产市场的消费主体 ,居民对住宅区位选择行为由过去的被动接受转变为主动选择。本文主要研究在这种新的住房制度下 ,影响城市居民住宅区位选择的因子。作者认为 ,房价的高低、住宅区位的交通通达性、环境条件是决定城市居民住宅区位选择的客观条件 ,居民自身的社会、经济、文化等特征、以及对不同住宅区位和环境的偏好也左右着住宅区位选择过程和结果。     

跨国银行在华发展区位研究

自中国对外开放以来，跨国银行积极在华开拓业务，目前已有来自18个国家和地区的68家银行在中国设立了158家分行。本文阐述了在华跨国银行的发展规律及区位指向，并初步分析了跨国银行来华发展的区位行为和动机，展望跨国银行在中国发展的策略取向。