Mining knowledge from result comparison between spatial clustering themes

This paper introduces some definitions and defines a set of calculating indexes to facilitate the research, and then presents an algorithm to complete the spatial clustering result comparison between different clustering themes. The research shows that some valuable spatial correlation patterns can be further found from the clustering result comparison with multi-themes, based on traditional spatial clustering as the first step. Those patterns can tell us what relations those themes have, and thus will help us have a deeper understanding of the studied spatial entities. An example is also given to demonstrate the principle and process of the method.     

主题公园声景观优化研究——以常州中华恐龙城为例

声景观是旅游景观研究的新领域,声景观的设计思想为景观研究与开发提供了新的理念.以常州中华恐龙城为例,研究游客对主题公园声景观的舒适度感知.研究发现,游客的声舒适度受到声音客观参数和主观感知的影响,当声景观音量处于特定阈值内时,游客声舒适度体验最为满意,同时游客对能够传递主题公园文化内涵的声音元素最为敏感.在此基础上,运用正设计、负设计和零设计的方法,提出了主题公园声景观优化设计的思路.     

High-resolution seismic tomography of the upper crust in the source region of the April 20, 2013 Lushan earthquake and its seismotectonic implications

Both P- and S-wave arrivals were collected for imaging upper crustal structures in the source region of the April 20, 2013 Lushan earthquake. High-resolution, three- dimensional P and S velocity models were constructed by travel-time tomography. Moreover, more than 3700 after- shocks of the Lushan earthquake were relocated via a grid search method. The P- and S-wave velocity images of the upper crust show largely similar characters, with high and low velocity anomalies, which mark the presence of sig- nificant lateral and vertical heterogeneity at the source region of the Lushan earthquake. The characteristics of the velocity anomalies also reflect the associated surface geo- logical tectonics in this region. The distributions of high velocity anomalies of both P- and S-waves to 18 km depth are consistent with the distributions of relocated after- shocks, suggesting that most of the ruptures were localized inside the high velocity region. In contrast, low P and S velocities were found in the surrounding regions without aftershocks, especially in the region to the northeast of the Lushan earthquake. For the relocated aftershocks of the Lushan earthquake from this study, we found that mostaftershocks were concentrated in a zone of about 40 km long and 20 km wide, and were located in the hanging wall of Dayi-Mingshan fault. The focal depths of aftershocks increase from the southeast to the northwest region in the direction perpendicular to the fault strike, suggesting that the fault ruptured at an approximate dip angle of 45°. The main depths of the aftershocks in the northwest of the main shock are significantly shallower than expected, revealing the different seismogenic conditions in the source region.     

The characteristics of shear wave splitting in the source region of the April 20, 2013 Lushan earthquake

Using seismic data of the aftershocks sequence of the April 20, 2013 Lushan earthquake recorded by seismic temporary and permanent stations in the source region, with the visual inspection of particle motion diagrams, this paper preliminarily contains the polarization directions of fast shear wave and the time-delays of split shear waves at every station, and analyzes the crustal anisotropic characteristics in the source region. In the study area, the polarization direc- tions at stations BAX, TQU, L 132, L 133, L 134, and L 135 are northeast, which is consistent with the strike of Dachuan- Shuangshi fault. There are two polarization directions at MDS and L131, which are northeast and southeast. The scatter of polarization directions suggests the complex stress field around these two stations where two faults intersect. For the normalized time-delays at every station, the range is 1.02-8.64 ms/km. The largest time-delay is from L134 which is closest to the mainshock, and the smallest one is from L133. The variations in time-delays show the decreasing at stations BAX, L134, and L135 because of the stress-relaxation after earthquake.     

无人机获取区域全景图试验

利用无人机灾情快速获取系统,以玉溪县城为工作区域,进行无人机区域航拍试验.通过开展无人机任务单元参数、飞行参数等试验,获得不同成像分辨率要求的最佳任务单元配置参数和飞行参数,获取高质量玉溪城区全景图像.试验证明,无人机灾情获取系统能够为应急救援决策和指挥等提供实时灾情信息,可显著增强快速响应能力.     

基于预处理广义极小残量法的大地电磁正演计算

有限单元法求解大地电磁正演问题,会形成大型稀疏的带状复系数矩阵方程组,其条件数大,易造成病态矩阵,求解极困难.为此,采用每步迭代都具有最优性的广义极小残量法(Generalized Minimal Residual)求解;但是,每步迭代的计算量和存储量都线性增长,造成迭代收敛速度慢,因此,引入不完全LU分解预处理技术以降低矩阵的条件数,加快广义极小残量法的收敛速度.通过二维模型和层状介质模型的电磁响应的计算表明,基于预处理广义最小残量法精确而稳定.     

PDA＋3S技术在土地变更调查中的应用研究

以陕西省宝鸡市土地变更调查为例,通过介绍PDA（掌上电脑）与GIS、GPS、RS等技术的结合在土地变更调查中的应用,探讨PDA与3S的结合在土地变更调查中的应用前景以及发展趋势。     

手持GPS/PDA数码调绘系统在地形数据生产中的应用研究

为满足使用手持GPS/PDA进行1∶10 000地形图野外调绘生产,以适应大面积、规模化基础测绘的要求,对GPS/PDA全野外调绘试生产进行总结和分析,提出相关的技术要求,为利用手持GPS/PDA进行野外调绘提供参考。     

基于CA模型的旅游小镇增长的时空模拟与应用——以河北三坡镇为例

旅游小镇增长的时空模拟是城镇化影响下的土地利用/覆盖变化研究的重要手段。近年来旅游小镇的城镇化以其旅游业发展带动城镇发展的独特模式引起国内外学者的高度关注。论文以元胞自动机模型为基础,运用旅游小镇旅游城镇化增长模型,对河北省三坡镇的旅游城镇化发展进行模拟与预测。模拟结果显示:①2005-2010年研究区城镇增长主要围绕现有镇区范围扩展,全域年均增速为0.015 km²/年;②2010-2015年主要城镇增长区位于镇内距离景区较近的苟各庄村附近,全域年均增速为0.040 km²/年,其他区域则保持相对较为平稳的状态。研究表明元胞自动机模型在模拟旅游小镇演化具有较高的可靠性,为研究城镇化条件下区域生态景观格局变化提供前提保证,对于提高土地资源利用效率,保障小镇健康有序发展具有十分重要的意义。     

利用船测数据以及Landsat-7 ETM+影像评估南极海冰区AMSR-E海冰密集度

利用第26次中国南极科学考察期间收集的海冰密集度船基观测资料以及由Landsat-7 ETM+得到的海冰密集度来验证AMSR-E南极海冰区海冰密集度产品的精度。AMSR-E海冰密集度与船基目视观测的海冰密集度存在着一定的线性关系(R²=0.816), 但两者匹配得并不是很好。与ETM+海冰密集度相比,AMSR-E数据趋向于低估海冰密集度,在25景晴空条件下的ETM+影像中,平均海冰密集度偏差(AMSR-E海冰密集度-ETM+海冰密集度)从-5.33%到-21.5%,而相应的均方根误差RMSE (Root Mean Squared Errors)从13.7%到33.8%。依据Landsat-7 ETM+ 海冰分类,AMSR-E数据海冰密集度最大的误差产生于新冰区。