Review on the Tempestite and the Significance in Xingwen     

ZHANG Bin  DENG Mao-lin  SHUI Wei  ZHOU Wei  WANG Xing-gui  MA Sha 《四川地质学报》2009,(Z1):160-164

Since G.Kelling put forward tempestite in 1973,the study has been developed quickly;especially the storm flow theory is known to be a milestone of sedimentology and the geology development as turbidite theory established in 1950s.This paper makes reviews on the development of tempestite theory:the origin and definitions,methods of the study,and its formation environment,scales,sedimentary characters,structures,sequences,model,and hummocky bedding were commented.It also explores the significance of the research on Tempestite of the Xingwen World Geopark.  相似文献   

Smoothing seismic tomograms with alpha-trimmed means   总被引：1，自引：0，他引：1  

A. Gersztenkorn  J. A. Scales 《Geophysical Journal International》1988,92(1):67-72

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A Clustering‐Based Approach to the Capacitated Facility Location Problem1     

Ke Liao  Diansheng Guo 《Transactions in GIS》2008,12(3):323-339

This research develops a clustering‐based location‐allocation method to the Capacitated Facility Location Problem (CFLP), which provides an approximate optimal solution to determine the location and coverage of a set of facilities to serve the demands of a large number of locations. The allocation is constrained by facility capacities – different facilities may have different capacities and the overall capacity may be inadequate to satisfy the total demands. This research transforms this special location‐allocation problem into a clustering model. The proposed approach has two parts: (1) the allocation of demands to facilities considering capacity constraints while minimizing the cost; and (2) the iterative optimization of facility locations using an adapted K‐means clustering method. The quality of a location‐allocation solution is measured using an objective function, which is the demand‐weighted distance from demand locations to their assigned facilities. The clustering‐based method is evaluated against an adapted Genetic Algorithm (GA) alternative, which integrates the allocation component as described above but uses GA operations to search for ‘optimal’ facility locations. Experiments and evaluations are carried out with various data sets (including both synthetic and real data).  相似文献   

卫星测高正常点海面高度计算方法研究   总被引：1，自引：0，他引：1  

刘传勇  黄谟涛  欧阳永忠  王克平  周坚  李红兵 《海洋测绘》2005,25(6):4-8

正常点海面高计算是卫星测高数据处理的基础.从测高卫星飞行轨道的规律出发,提出了采用“距离加权平均”计算正常点海面高的新方法,阐述了“距离加权平均”这一方法计算正常点海面高的原理.并分别利用传统方法和新方法所计算出的中国海域内正常点海面高数据,进行交叉点海面高不符值及其平差计算,对所得结果进行精度评定.实际计算结果比对证明了利用“距离加权平均”法计算正常点海面高的可行性和优越性.  相似文献   

几种图像去噪算法的对比分析     

谭攀  姜超 《测绘与空间地理信息》2014,(7):39-42

图像去噪作为一种重要的预处理手段,一直以来都是图像处理和计算机视觉领域的研究热点。去噪算法的难点在于去除噪声的同时尽可能保持原始信息的完整性。本文主要研究TV,BLS-GSM,NLM以及BM3D四种经典去噪算法的基本原理,并用模拟数据验证分析四种算法在图像去噪中的性能,实验证明,四种算法均能在保留图像细节的前提下很好的去除噪声,其中,BM3D算法在保证去噪质量的同时效率最高。  相似文献   

改进的多视PolSAR非局部均值滤波算法     

陈建宏  赵拥军  黄洁  刘伟  赖涛 《测绘科学技术学报》2014,(5)

像素点间相似性度量是非局部均值滤波算法的关键所在。从信息论角度出发,提出了一种改进的多视Pol SAR非局部均值滤波方法。该算法在综合分析各类矩阵测度基础上,选定Kullback-Leibler距离作为最优相似度量,结合多视极化相干矩阵服从复Wishart分布,给出了极化相干矩阵的KL距离,并在预处理中应用了极化旋转。实验结果表明,改进方法能够在保持边缘细节的同时有效抑制相干斑。  相似文献   

自适应非局部均值地震随机噪声压制(英文)   总被引：2，自引：1，他引：1  

尚帅  韩立国  吕庆田  谭尘青 《应用地球物理》2013,10(1):33-40

非局部均值滤波是一种基于图像信息冗余的去噪方法,其认为图像自身的有效结构具有一定的重复性,而随机噪声则不具备这一特点,通过利用图像本身的自相似性来达到压制随机噪声的目的,是一种全局的去噪方法。本文把这一思想引入地震数据随机噪声压制中,针对传统非局部均值滤波计算量过大的问题,文章采用分块非局部均值的方式来减少计算量;针对滤波参数选取会影响非局部均值滤波效果的问题,提出一种简单的自适应滤波参数地震数据分块非局部均值算法。模型和实际数据处理结果表明:相对于传统的去噪算法(如f-x反褶积),该方法在压制随机噪声的同时对有效信号保护地更好,具有更高的保真度,更有利于后续的处理和解释工作。  相似文献   

2014年夏初南疆一次持续性强降雨过程的水汽和动力条件分析     

王江  周雅蔓  王昀  李如琦 《干旱区地理》2015,38(6):1103-1111

全球变暖背景下,极端降水事件频次增多强度增大,对年降水量变化影响显著。2014年6月17~24日,塔里木盆地出现了持续性强降水过程.利用观测资料和NCEP/NCAR逐日6 h再分析资料,对强降水过程的水汽和动力条件进行了诊断分析。结果表明,此次强降水过程,垂直上升运动剧烈区域及水汽辐合区域与大降水的落区近乎吻合。中低空偏东急流加强了气旋的发展,增强了上升运动,且急流的大小决定了塔里木盆地大降水的强度,急流西伸的位置决定了降水的区域。中低空偏东急流轴末端的左侧,对应着大降水的发生区域。主要水汽源地为中亚地区、阿拉伯海和孟加拉湾,其中孟加拉湾和阿拉伯海的水汽通过季风环流输送至青藏高原,再通过高空平流和中低空回流的方式输送至塔里木盆地。  相似文献   

Accounting for Extensive Secondary Information to Improve Watertable Mapping   总被引：2，自引：0，他引：2  

M. N. M. Boezio  J. F. C. L. Costa  J. C. Koppe 《Natural Resources Research》2006,15(1):33-48

Generally, multiple variables are sampled in addition to the one used to quantify the main phenomenon under study. In some situations, this secondary information is sampled exhaustively for the study area and can be incorporated for helping in estimating the variable of interest. There are several methodologies available for incorporating densely sampled secondary information. Collocated cokriging is one of these methodologies and has the advantage to other methodologies, of accounting for spatial correlation. However, one drawback in its application comes from the difficulty in modeling the coregionalization. Simplified models of coregionalization were developed specifically for the collocated cokriging case. This paper presents, through a case study, the incorporation of dense secondary information using collocated cokriging. The watertable above a coal underground mine is mapped using water-level readings at monitoring piezometers complemented by highly correlated topographic data. The incorporation of dense secondary information through the utilization of a linear model of coregionalization and Markov models is comparatively evaluated in various aspects such as mathematical quality, coherence with the natural phenomena and the ease of utilization and modeling. Simple kriging with local varying means also is evaluated as it accounts for nonstationarity and is easily implemented. All these methods that incorporate topography as secondary information for mapping the watertable provided maps more in accordance with the natural phenomena than ordinary kriging using the principal attribute solely. Among these methods, strictly collocated cokriging using a linear model of coregionalization showed overall superior performance.  相似文献   

煤田构造研究——思路与方法   总被引：2，自引：1，他引：2  

曹代勇 《中国煤田地质》2006,18(6):1-4

中国含煤岩系赋存状况的显著特点,是后期构造变形及其变形的时空差异性,造成这种特殊煤田地质条件的控制因素主要包括地球动力学环境、构造演化进程、深部构造与基底属性、构造应力场作用、煤系和上覆下伏岩性组合等五个方面。针对我国煤田构造的发育特点,提出了煤田构造研究的思路,总结了适用于煤田构造研究的技术手段及其主要用途。  相似文献