Self-organised clustering for road extraction in classified imagery

The extraction of road networks from digital imagery is a fundamental image analysis operation. Common problems encountered in automated road extraction include high sensitivity to typical scene clutter in high-resolution imagery, and inefficiency to meaningfully exploit multispectral imagery (MSI). With a ground sample distance (GSD) of less than 2 m per pixel, roads can be broadly described as elongated regions. We propose an approach of elongated region-based analysis for 2D road extraction from high-resolution imagery, which is suitable for MSI, and is insensitive to conventional edge definition. A self-organising road map (SORM) algorithm is presented, inspired from a specialised variation of Kohonen's self-organising map (SOM) neural network algorithm. A spectrally classified high-resolution image is assumed to be the input for our analysis. Our approach proceeds by performing spatial cluster analysis as a mid-level processing technique. This allows us to improve tolerance to road clutter in high-resolution images, and to minimise the effect on road extraction of common classification errors. This approach is designed in consideration of the emerging trend towards high-resolution multispectral sensors. Preliminary results demonstrate robust road extraction ability due to the non-local approach, when presented with noisy input.     

陀螺经纬仪跟踪式观测逆转点数据的平差模型

针对跟踪式定向观测中的逆转点数据 ,采用Schuler Wolf模型替代传统的等权处理 ,并对该模型进行了改造 ,包括初始信号作为参数求解、关联系数 ρ进行迭代估计等 ;用多项式衰减替代理想情况下的指数衰减 ,作为平差处理的函数模型。实测数据解算结果表明 ,由此组成的逆转点平差模型具有解算精度高、残差为白噪声信号、参数求解比较稳定等优点。     

PERFORMANCE ANALYSIS OF INTEGRATED GPS/GLONASS CARRIER PHASE-BASED POSITIONING

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南海及邻区地壳上地幔三维S波速度结构的面波波形反演>.

对南海及邻区中国数字地震台网４个台站接收到的328条长周期地震记录的面波波形进行分块波形反演．分块波形反演把大尺度的优化问题转化为小尺度的优化问题，采用非线性优化方法求解，从而得到南海及邻区22网格划分、从地表深至430ｋｍ 的地壳上地幔三维S波速度结构，并用检验板法进行了分辨率分析．结果表明，海域、岛弧和大陆在速度分布、岩石圈和软流圈存在明显的结构差异．      

Living with floods: victims' perceptions in Beijiang, Guangdong, China

This study revealed the collective values of the flood victims in the Beijiang area, Guangdong, China, as a result of a hazardous flood in 1994. The victims were sceptical of large flood-prevention engineering structures. They believed that flooding was unavoidable, but by extending support networks, applying hazard-resistant designs, and developing loss-sharing adjustments the disastrous effects of a flood could be mitigated. Seemingly, victims were prepared to live with floods and adopted functional adjustments to lessen flood impact.     

国外大都市区管理的实践及其借鉴

大都市政府和都市议会是发达国家对大都市区和都市连绵区进行宏观管理的重要机构，本文简要介绍了各种类型的大都市政府和都市议会的形成与发展，在此基础上提出了我国相应的宏观管理机构为城镇密集区政府和都市区规划局，最后，对我国城镇密集区规划管理的可行性与规划管理体系问题进行了讨论。     

Textural attributes, mineralogy and provenance of sand dune fields in the greater Al Ain area, United Arab Emirates

Sand dunes and interdune sediments around Al Ain city have markedly high carbonate contents which increase towards Jabal Hafit mountain and the Arabian Gulf coast. The dunes are composed predominantly of well-sorted fine sands, consisting of unstrained quartz and carbonate grains together with minor proportions of chert and feldspars. Scanning electron microscope (SEM) examination reveals that quartz grains display various mechanically- and chemically-formed surface textures. The heavy minerals are dominated by opaques and pyroxenes with minor tourmaline, garnet, rutile, epidote, monazite, zircon, hornblende and staurolite.Interdune sediments consist of fine and very fine, poorly- to extremely poorly-sorted sands together with small concentrations of gravel, silt and clay. The light sand fractions compositionally resemble those of dunes but contain, in addition, gypsum, anhydrite, halite and celestite. Percentages of pyroxenes are higher whereas those of zircon, tourmaline and rutile are lower than in dunes. X-ray diffractometry reveals that the clay fractions consist solely of palygorskite. Generally, interdune sediments are much less mature texturally and mineralogically than dune sands; the maturity of both types of sediments decreases toward the NE of the study area.Sand dunes in the various districts of the greater Al Ain area are genetically related. Also, there is a partial genetic relationship between the dunes and interdune sediments; both are mainly multicyclic. Their major parts were brought mainly by the dominant north-west (El Shamal) winds from older dune fields in other localities in U.A.E., Qatar and El-Rub El-Khali. Local contributions to the dune fields from Jabal Hafit mountain, the Oman Mountains and the calcareous coast of the Arabian Gulf were, in cases, significant. Also, authigenesis by groundwater under highly evaporitic conditions played a major role in the formation of interdune sediments through the genesis of the clay and some nonclay minerals.     

Centralized power and divided space: `Fractured regions' in the Israeli `ethnocracy'

This paper uses a critical political-geographical perspective to account for the high centrality of power found in Israel. It suggests that the concentration of power have not been solely caused by national solidarity and integration or by metropolitan development, as commonly explained, but also by the territorial `fracturing' of the main social and ethnic groups in Israel/Palestine. This has prevented the emergence of effective pressure for regional devolution. Israel's character as a settler and settling state, and its central project of Judaizing contested territories, enabled the Israeli `ethnocracy' and its (mainly Ashkenazi and secular) elites to create a political geography of `fractured ethnic and social regions'. Dispersing minorities and legitimizing segregation and inequality, all in the name of the `national interest', achieved this. The Israeli political landscape is therefore organized as `fractured regions', each representing a distinct and interconnected, yet geographically dispersed, set of localities, and resembling a `chain of beads'. The logic of dispersal and segregation, in turn, has also influenced patterns of development and residential separation within Israel's main urban areas. Thus, ethnic and social fragmentation and conflict, and not a putative process of national or metropolitan integration, can explain much of Israel's highly centralized power structure.     

干旱、半干旱区域降水趋势可预报期限的初步研究

应用中国西北和美洲大陆中部干旱、半干旱区域７个长记录站的月降水量记录，分析了降水趋势的可预报期限问题。结果表明：月降水量标准化系数序列的可预报尺度为３个月左右。将该序列进行差分运算后，误差倍增时间会显著加长。     

Seismotectonic deformation during the filling of Toktogul Reservoir,Kirghizia

Natural seismicity and induced seismic events are discussed in the context of the seismotectonic deformation method through the example of earthquakes in the Toktogul Reservoir region in the Central Tien Shan, Kirghizia. The parameters of seismotectonic deformation of various sites in the Toktogul Reservoir region are described, based on a statistical study of focal mechanisms. The relationship of induced seismicity to changes of water level in the reservoir is reviewed. The temporal stress-strain characteristics are investigated. Average focal mechanisms for the entire region, as well as areas in the immediate vicinity of Toktogul Dam are analyzed. The vertical component of seismotectonic deformation varies in time from compression to extension-opposite to what is expected from the influence of the reservoir load; strike-slip motions become oblique thrusts. Changes in the orientation of focal mechanisms coincide with the time of maximum rate of the filling of the reservoir.