基于超像元词包特征和主动学习的高分遥感影像变化检测     

杨进一  徐伟铭  王成军  翁谦 《地球信息科学学报》2019,21(10):1594-1607

为解决高分辨率遥感影像变化检测中存在底层特征缺乏语义信息、像元级的检测结果存在“椒盐”现象以及监督分类中样本标注自动化程度较低,本文提出一种基于超像元词包特征和主动学习的变化检测方法。首先采用熵率分割算法获取叠加影像的超像元对象;其次提取两期影像像元点对间的邻近相关影像特征（相关度、斜率和截距）和顾及邻域的纹理变化强度特征（均值、方差、同质性和相异性）,经线性组合作为像元点对的底层特征;然后基于像元点对底层特征利用BOW模型构建超像元词包特征,并采用一种改进标注策略的主动学习方法从无标记样本池中优选信息量较大的样本,且自动标注样本类别;最后训练分类器模型完成变化检测。通过选用2组不同地区的GF-2影像和Worldview-Ⅱ影像作为数据源进行实验,实验结果中2组数据集的F1分数分别为0.8714、0.8554,正确率分别为0.9148、0.9022,漏检率分别为0.1681、0.1868,误检率分别为0.0852、0.0978。结果表明,该法能有效识别变化区域、提高变化检测精度。此外,传统主动学习方法与改进标注策略的主动学习方法的学习曲线对比显示,改进的标注策略可在较低精度损失下,有效提高样本标注自动化程度。  相似文献   

浅层地震剖面揭示固原市清水河东侧断裂特征     

花鑫升  姬计法  酆少英  杜鹏  宋威  刘增祺 《大地测量与地球动力学》2019,39(8):794-797

为查明清水河东侧断裂的产状、性质及其浅部构造特征，跨断裂开展高分辨率的浅层地震探测，获得高信噪比的浅层地震反射叠加剖面。根据浅层地震剖面结果并结合该区域地质资料，对该断裂的浅部构造特征进行分析和讨论。结果表明，清水河东侧断裂为一条走向近SN、倾向E的逆断层，其浅部为由2~3条断层组成的“Y”字形构造，并错断埋深约10~30 m的第四系沉积层，属第四纪以来的隐伏活动断裂。  相似文献   

太行山南端浅层速度结构成像和隐伏断裂探测   总被引：1，自引：0，他引：1  

徐增波  刘保金  姬计法  鄷少英  袁洪克  谭雅丽  王宏伟 《大地测量与地球动力学》2019,39(1):88-92

利用太行山南端的深地震反射剖面数据，运用初至波层析成像方法反演得到该区域的浅层P波速度结构和基底面展布形态，发现剖面浅部的P波速度变化与沉积盖层厚度和断裂分布有着较好的对应关系。利用跨断裂完成的浅层地震反射剖面，对区域内2条第四纪隐伏活动断裂进行高分辨率成像。结果表明，汤西断裂为东倾的正断层，控制汤阴地堑的西边界，活动年代为中更新世；汤东断裂为西倾的正断层，是汤阴地堑的主控边界断裂，活动年代为晚更新世。  相似文献   

Main active faults and seismic activity along the Yangtze River Economic Belt: Based on remote sensing geological survey     

《China Geology》2020,3(2):314-338

The Yangtze River Economic Belt (YREB) spans three terrain steps in China and features diverse topography that is characterized by significant differences in geological structure and present-day crustal deformation. Active faults and seismic activity are important geological factors for the planning and development of the YREB. In this paper, the spatial distribution and activity of 165 active faults that exist along the YREB have been compiled from previous findings, using both remote-sensing data and geological survey results. The crustal stability of seven particularly noteworthy typical active fault zones and their potential effects on the crustal stability of the urban agglomerations are analyzed. The main active fault zones in the western YREB, together with the neighboring regional active faults, make up an arc fault block region comprising primarily of Sichuan-Yunnan and a “Sichuan-Yunnan arc rotational-shear active tectonic system” strong deformation region that features rotation, shear and extensional deformation. The active faults in the central-eastern YREB, with seven NE-NNE and seven NW-NWW active faults (the “7-longitudinal, 7-horizontal” pattern), macroscopically make up a “chessboard tectonic system” medium-weak deformation region in the geomechanical tectonic system. They are also the main geological constraints for the crustal stability of the YREB.  相似文献   

Degradation of Atenolol with Electrochemical Oxidation at Mixed Metal Oxide Electrodes Assisted by UV Photolysis          下载免费PDF全文

Shumin Zhu  Bingzhi Dong  Shiqing Zhou 《洁净——土壤、空气、水》2018,46(4)

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HOLOCENE ACTIVE CHARACTERISTICS OF THE NORTHERN SEGMENT OF THE MINJIANG FAULT IN THE EASTERN MARGIN OF THE TIBETAN PLATEAU     

LI Feng  LIU Hua-guo  JIA Qi-chao  XU Xi-wei  ZHANG Xiao-liang  GONG Fei 《地震地质》2018,40(1):97-106

As a part of the north-south seismic zone in China, a lot of M6.0-7.2 earthquakes have occurred in the margin faults of the Minshan block in history. This work attempted to characterize the geometry and activity of the north section of the Minjiang fault in this region based on high-resolution satellite images, geologic and geomorphic investigations, micro-geomorphic surveys, and trench excavation. The results show left-lateral-slip and Holocene activity of this structure. Along it, the offset landform has a continuous linearity on Ⅱ terraces near the Chuanpan village. The vertical height of the fault scarp measures 3.1 meters, which is almost the same as the accumulative horizontal displacement of the gully. The accumulative horizontal shortening due to faulting is 3.0 meters. Calculation using the model of displacement-dependent characteristic earthquakes shows both the vertical and horizontal co-seismic displacements and the horizontal shortening amount are about 1.0 meter. While strata dating suggests that the vertical and horizontal slip rates are all about 0.7-0.9mm/a, and the horizontal shortening rate is approximately 1.0-1.1mm/a. The excavated trench, perpendicular to the fault trace, reveals low-angle thrust dipping in 260åt 29°. From the relationship of the fault, colluvial wedge and stratigraphy ages, three palaeoseismic events are identified from youngest to oldest at 0-295a BP, 1 405-1 565a BP, and 2 750-2 875a BP, respectively, with recurrence intervals 1 110-1 565 years and elapsed time about 0-295 years。According to the relationship between magnitude and active parameters, it is considered that the northern segment of the Minjiang fault is capable of generating M7 or greater earthquakes. Now it is in the process of stress accumulation, having a certain seismic risk.  相似文献   

A simple strategy for dynamic substructuring: I. Concept and development     

Aikaterini Stefanaki  M. V. Sivaselvan 《地震工程与结构动力学》2018,47(9):1801-1822

Dynamic substructuring refers to physical testing with computational models in the loop. This paper presents a new strategy for such testing. The key feature of this strategy is that it decouples the substructuring controller from the physical subsystem. Unlike conventional approaches, it does not explicitly include a tracking controller. Consequently, the design and implementation of the substructuring controls are greatly simplified. This paper motivates the strategy and discusses the main concept along with details of the substructuring control design. The focus is on configurations that use shake tables and active mass drivers. An extensive experimental assessment of the new strategy is presented in a companion paper, where the influence of various factors such as virtual subsystem dynamics, control gains, and nonlinearities is investigated, and it is shown that robustly stable and accurate substructuring is achieved.  相似文献   

茅山竹矿断层气定点观测场地勘选     

戴波  吴晓峰  张敏  孟科 《大地测量与地球动力学》2019,39(11):1202-1206

拟在茅山断裂带沿线布设若干个断层气连续观测点，建组断层气观测网。以茅山竹矿地区为例，通过断层气测量的初步结果，结合地质、人工地震、跨断层短水准等多种手段联合分析研究区断层的活动性，从而确定断层气定点观测的点位，为组建断层气观测网的选点提供借鉴和参考。  相似文献   

高分辨率反射波地震勘探在城市隐伏断裂探测中的应用——以成都天府新区苏码头断裂为例     

刘远志  刘胜  李大虎  夏友钢  李颖  周德帅 《大地测量与地球动力学》2019,39(9):910-915

采用“三小三高二绝招”的工作方法，通过静校正、多域多方法联合噪音衰减和精细的速度分析获得较高分辨率的地震时间剖面，揭示苏码头断裂的展布位置、构造形态及变形样式等。结果表明，区域构造以冲起式为主，在反冲断层与逆冲断层之间形成冲起构造或逆冲三角构造，在地震剖面上有明显的楔状特征。通过地震测线的断层走向以NE为主，倾向以SE为主，部分断层倾向为NW。  相似文献   

Responses of chemically active and naturally fractured shale under time‐dependent mechanical loading and ionic solution exposure          下载免费PDF全文

Chao Liu  Son K. Hoang  Younane N. Abousleiman 《国际地质力学数值与分析法杂志》2018,42(1):34-69

In this paper, the analytical dual‐porosity dual‐permeability poromechanics solution for saturated cylinders is extended to account for electrokinetic effects and material transverse isotropy, which simulate the responses of chemically active naturally fractured shale under time‐dependent mechanical loading and ionic solution exposure. The solution addresses the stresses, fracture pore pressure, matrix pore pressure, fluid fluxes, ion concentration evolution, and displacements due to the applied stress, pore pressure, and solute concentration difference between the sample and the circulation fluid. The presented solution will not only help validate numerical simulations but also assist in calibrating and interpreting laboratory results on dual‐porosity dual‐permeability shale. It is recommended that the analytical solutions of radial and axial displacements be used to match the corresponding laboratory‐recorded data to determine shale dual permeability and chemo‐electrical parameters including membrane coefficient, ions diffusion coefficients, and electro‐osmotic permeability.  相似文献