面向应用的高光谱影像分类方法

提出了一种面向应用的高光谱影像分类方法,旨在从根本上、全方位地削弱各种不利因素对该类影像分类精度的影响.主要包括利用IEM算法获取更为精确的类别分布信息,采用Tabu搜索算法进行原始特征空间的降维,运用基于混合规则的组合分类器来判断待识样本的类别标签.实验表明,按照该方法进行高光谱影像的分类处理,可以得到很高精度的分类结果.     

基于变步长加速搜索的微震源定位方法

微震定位方法是微震监测技术的重要组成部分,其关键是定位震源位置。利用空间网格划分并计算网格交点目标函数值,对微震定位目标函数二维及三维空间分布进行了分析,并据此获取了目标函数连续且极小值唯一、单轴收敛范围逐步减小、各轴收敛范围不一的规律。利用以上规律及模式搜索法、网格搜索法的优缺点,探索出了基于连续比较模块、变步长模块、加速模块的变步长加速搜索法。通过模拟算例与工程数据下收敛稳定性、结果精确度、计算速度以及参数初始值影响程度4个指标的效果对比,结果表明：模拟算例下,对比模拟退火算法、遗传算法,变步长加速搜索法的目标函数值标准差、定位误差标准差、波速误差标准差均为0;该算法的定位误差平均值分别为其余二者的0.7%、1.9%;该算法的计算时间平均值分别为其余二者的6.9%、33.2%。该算法单独更改各参数对定位误差的影响在0.005～0.025 m之间;减小搜索步长下限可有效提高结果精确度,并增加相应的计算时间。在规定初至到时与目标函数模型及检波器位置坐标下,搜索算法对定位精度无实质影响。     

The March–April 2014 sequence of earthquakes in North Chile

During March–April 2014 a series of earthquakes occurred around the Iquique city located in the northern Chile region. The two largest events of this sequence are the Mw8.2, April 1, 2014 and Mw7.7, April 4, 2014 quakes. Here we computed the nodal planes of eight of the large and well teleseismically recorded events of this series based on grid search, teleseismic moment tensors inversion, empirical Green's function deconvolution and its stack to average the deconvolutions for the Mw = 8.2, April 1, 2014, synthetic Green's function deconvolution and its stack to average the deconvolutions for the same event and 3D static deformation analysis of the above mentioned events based on the AK135 model. Grid search nodal planes and moment tensors suggest the dominance of reverse faulting. Almost all of the calculated teleseismic moment tensors represent a considerable amount of DC (usually more than 90%) and lower amount of CLVD for this sequence of events. Empirical and synthetic Green's function deconvolution showing down dip rupture propagation and 3D static deformation representing higher amount of vertical deformation in comparison with horizontal deformation components plus the existence of uplift and subsidence. According to the aftershocks distribution there is a bilateral distribution of the aftershocks around the first large event of this sequence that occurred March 16, 2014 (Mw6.7) so that they are approximately limited between the Mw8.2 (at north) and Mw7.7 (at south) quakes. Moreover there exist two bands of regional seismicity during early-mid 2014: a shallow off-shore band between the trench and coast and a deeper inland band under the active volcanic chain (both nearly parallel to the trench).     

江苏矿产资源潜力评价成果数据集成及应用

数据的集成管理是项目成果应用的必要方式。从数据库管理角度,介绍了江苏矿产资源潜力评价成果数据的集成情况;并通过数据库的集成管理,可按图件类型、专题内容、空间范围等方式进行数据查询检索,辅助相关专业开展综合编图研究工作     

测绘档案管理系统的技术研究

介绍了基于ES-OAIS系统的测绘资料档案系统的主要结构和系统主要特点,建立了管理各类测绘档案库,提高了档案的安全性和信息资源的利用率。     

鄂尔多斯盆地南缘城阳—武沟地区航放异常铀找矿前景分析

研究区位于鄂尔多斯盆地南缘西部,处于天环凹陷西翼,分布有Ⅰ-160砂岩型铀矿点。笔者依据对前人资料的收集、整理,结合研究区分布的航空放射性异常查证结果,对区内铀成矿条件进行分析,探讨了铀找矿前景。分析认为城阳—武沟地区存在有利的找矿目的层,具备较好的砂岩型铀成矿条件,航空放射性异常区是重点找矿地段,圈定了1片铀找矿有利区。     

基于三维GIS技术的地震灾情场景模拟系统

设计并实现了基于三维GIS技术的地震灾情场景模拟系统。根据现场救援工作的特点和需求,对基于基础地理信息数据的自动三维建模方法和场景生成技术进行了研究,建立了基于地震动影响场和结构易损性的地震灾情场景模型;基于ArcGISEngine开发组件,实现了灾前、灾后场景的自动生成和直观显示,实现了整体破坏情况分析、重点搜索区域判定、关键目标震害与属性查询等灾情分析和辅助决策功能。该系统以震区基础地理信息数据和地震基本参数作为数据源,可以在获得地震基本参数之后快速地估计和分析震区建筑结构的破坏及其空间分布情况,预判重点搜索救援区域,为应急指挥决策和救援行动提供有效的支持,适合在现场救援工作中实际应用。     

乌东德地区泥石流危险范围预测模型

为了更加客观、准确地预测泥石流的危险范围,在前人研究经验和大量野外考察的基础上,选取多项泥石流重要影响因素,对乌东德地区上百条泥石流按照其堆积区规模分组进行多元回归分析,得到不同类型泥石流中各影响因素对堆积区形态参数的预测模型。通过不断改变步长的方式搜索适用于一个地区泥石流危险范围预测的数学模型,运用计算机搜索大量可能的数学模型,通过平均误差计算比较得到最优预测模型。将该方法和文献[3]的逐步回归分析方法一起应用到乌东德地区的实例上进行验证,预测结果显示,后者得到的误差要比本文方法计算的误差大很多,本文方法的预测误差为6.7%～9.2%,文献[3]方法的预测误差为10.5%～29.6%。     

The May 23 and 24, 1994 Taiwan earthquakes: comparison of source process between the two events

Inversion for the seismic fault rupture history is an important way to study the nature of the earthquake source. In this paper, we have selected two Taiwan earthquakes that occurred closely in time and located in the same region, inversed the distribution of the slip amplitudes, rakes, risetimes and the rupture times on the fault planes by using GDSN broad-band and long-period records and the adaptive hybrid global search algorithm, and compared the two events. The slip rate of every subfault calculated provides information about the distribution of tectonic stress and fault strength. To the former event (MS=6.0), the maximum slip amplitude 2.4 m and the minimum risetime 1.2 s are both located at the hypocentre. The latter earthquake (MS=6.6) consisted of two subevents and the second source has 4 s delay. The maximum slip amplitude 0.9 m located near hypocentre is corresponding to the minimum risetime 1.4 s, and the corresponding maximum slip rate 0.7 m.s-1 is similar to the peak value of other large slip rate areas. We consider that the latter event has more complicated temporal-spatial distribution than the former.     

Optimal damper placement for building structures including surface ground amplification

A systematic method for optimal added damper placement in building structures is developed, taking into account the response amplification due to the surface ground. Non-linear amplification of the surface ground is described by an equivalent linear model. Hysteretic damping of the surface ground and radiational damping into the semi-infinite visco-elastic ground are included in the model. An original steepest direction search algorithm is applied to the interaction model. Closed-form expressions of the inverse of the coefficient matrix (tri-diagonal matrix) enable one to compute the transfer function and its derivative with respect to design variables very efficiently. It is shown that the ratio of the fundamental natural period of the structure to that of the surface ground is a key parameter for characterizing the optimal damper placement. Several examples for different soil conditions are presented to demonstrate the effectiveness and validity of the present method.