规则池塘群的复杂直线模式识别     

刘呈熠  武芳  巩现勇  行瑞星  罗登瀚 《测绘学报》2020,49(2):256-266

针对现有面要素直线模式识别方法难以解决规则池塘中破碎区域的问题,提出了一种规则池塘群的复杂直线模式识别方法。首先,分析了规则池塘群的空间特征和认知特点,提出了“主次关系→并列关系→直线模式→复杂直线模式”的多层次认知顺序;其次,设计了主次关系池塘组、并列关系池塘组、直线模式池塘群的识别方法;最后,构建了复杂直线模式池塘群的识别模型。试验表明:本文方法能够消除破碎区域对规则池塘群直线模式提取的不利影响,有效提升复杂直线模式识别的质量。  相似文献   

Three-dimensional finite element simulation of fracture propagation in rock specimens with pre-existing fissure(s) under compression and their strength analysis     

Ramin Pakzad  Shanyong Wang  Scott W. Sloan 《国际地质力学数值与分析法杂志》2020,44(10):1472-1494

A FORTRAN program, consistent with the commercially available finite element (FE) code ABAQUS, is developed based on a three-dimensional (3D) linear elastic brittle damage constitutive model with two damage criteria. To consider the heterogeneity of rock, the developed FORTRAN program is used to set the stiffness and strength properties of each element of the FE model following a Weibull distribution function. The reliability of the program is assessed against available experimental results for granite cylindrical specimens with a throughgoing, flat and inclined fissure. The calibration procedure of the material parameters is explained in detail, and it is shown that the compressive to tensile strength ratio can have a substantial influence on the failure response of the specimens. Numerical simulations are conducted for models with different levels of heterogeneity. The results show a smaller load bearing capacity for models with less homogeneity, representing gradual coalescence of fully damaged elements forming throughout the models during loading. The maximum load bearing capacity is studied for various combinations of inclination angles of two centrally aligned, throughgoing and flat fissures of equal length embedded in cylindrical models under uniaxial and multiaxial loading conditions. The key role of the compressive to tensile strength ratio is highlighted by repeating certain simulations with a lower compressive to tensile strength ratio. It is proven that the peak loads of the rock models with sufficiently small compressive to tensile strength ratios containing two throughgoing fissures of equal length are similar, provided that the minimum inclination angles of the models are the same. The results are presented and discussed with respect to the existing experimental findings in the literature, suggesting that the numerical model applied in this study can provide useful insight into the failure behaviour of rock-like materials.  相似文献   

大别山及其周边现今垂直形变研究     

宋尚武  王庆良  郝明  周琳  刘立炜  胡亚轩 《大地测量与地球动力学》2018,38(1):32-35

基于1980年、2005年和2015年3期区域精密水准网观测资料，利用线性动态平差模型计算获取大别山地区水准网长期垂直运动速度场图像。研究发现，淮河平原地表下沉较为严重，大别山呈现弱隆升趋势运动，长江谷地边缘地区较大别山区呈现明显的隆升运动。跨郯庐断裂带水准剖面结果显示，垂直运动与地形呈负相关和弱相关。  相似文献   

基于直线感知增强的边缘提取算法   总被引：1，自引：1，他引：0  

张帆  黄先锋  李德仁  张璇 《武汉大学学报(信息科学版)》2009,34(1)

根据视觉识别边缘的感知特性,提出了一种基于直线感知增强的弱边缘的边缘提取算法。借鉴视觉的直线感知方式,针对弱边缘整体上呈直线分布的特点将其筛选出来,进行编组、连接和扩展。与Edison边缘提取算子的比较实验证明,本算法在对弱边缘的提取和虚假边缘的抑制上有显著增强。  相似文献   

Optimal Filtering Algorithm for Stochastic 2-D FMM Ⅱ with Multiplicative Noise     

CHUDongsheng LIANGMeng SHIXin ZHANGLing 《中国海洋大学学报(英文版)》2004,3(1):106-110

1　Introduction　Inrecentyearstherehasbeengrowingresearchin terestinthetwo dimensional (2 D )systemtheory .The 2 Dsystemsmayfindapplicationsinareassuchasmarineseismicdataprocessingandimageprocessing .Althoughmoreandmorevaluableresultshavebeengained ,mos…  相似文献   

居民收入与通信网络市场经济效益研究--以河北省通信网络为实例     

刘江林  李应良  石宏宇 《成都信息工程学院学报》2005,20(6):662-666

利用Logisitic曲线模型和扩展支撑模型对居民可支配收入预测和单项消费预测，以河北省居民的收入及其消费支出为实例，研究了城镇居民和农民的可支配收入分配和单项边际消费倾向，合理建立了预测模型，并理论计算了1999～2003年的通信消费方面的边际消费倾向、预测了2004～2008年通信消费情况。最后，根据预测结果对通信网络建设提出了一些有价值的建议。  相似文献   

嵌入式时间间隔计数器的研制     

樊战友  胡永辉  边玉敬 《时间频率学报》2005,28(1):7-14

介绍了一种新研制的嵌入式时间间隔计数器，它可作为一种功能模块用于用户的设备或时统中，实现高精度时间测量。从基本原理、硬、软件和功能等不同角度对计数器进行了较为详细的讨论。在该计数器的研制过程中还开发了用来调试计数器和供计数器用户使用的计算机应用软件，对此也作了简要介绍。最后，给出了计数器的设计指标和一些实测数据。  相似文献   

A high resolution,multiproxy Late‐glacial record of climate change and intrasystem responses in northwest England     

Richard T. Jones  Jim D. Marshall  Stephen F. Crowley  Alan Bedford  Nigel Richardson  Jan Bloemendal  Frank Oldfield 《第四纪科学杂志》2002,17(4):329-340

A lacustrine carbonate sequence from Hawes Water, Lancashire, UK, has been studied using stable isotopic, lithological, pollen and mineral magnetic analysis. The data reveal four abrupt climatic oscillations in the Late‐glacial Interstadial leading up to the onset of the Loch Lomond Stadial. The data also point to climatic warming relatively early within the stadial, ca. 12 500 GRIP yr, prior to the onset of the Holocene. The oxygen isotope record is taken as a signature of climate forcing against which the response of the lake‐system can be monitored. By adopting this approach it is revealed that the response of the biological system to the rapid climatic oscillations is non‐linear and primarily a function of the antecedent conditions. A significant end‐Devensian isotopic excursion (A) is matched by only minor changes in the cold‐adapted floras and faunas. During the warmer interstadial, the response of the biological ecosystem (events B–D) is clearly influenced by thresholds: major changes in the catchment vegetation associated with relatively minor oscillations in the isotopic signature. The stratigraphical patterns reveal significant lag effects between the onset of climate deterioration and resulting changes in vegetation. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

LAMOST总控系统程序设计     

徐灵哲  徐欣圻 《天文学进展》2005,23(3):287-292

国家重大科学工程项目LAMOST总控系统的程序设计是一个庞大的软件工程．其总控系统下共包括8个既相互独立又互有关联的子系统．如何通过良好的软件设计方法来处理好这8个子系统之间的关系使其协调运转，以及如何确保软件开发的可维护性、可持续性是研究重点．  相似文献   

利用高光谱数据进行植被生化成分反演方法研究   总被引：3，自引：0，他引：3  

张凤丽  万余庆 《地球信息科学学报》2001,3(4):71-75

高光谱数据包含着丰富光谱信息,能够定量地分析物质成分^[1]。由高光谱数据,可以运用多元逐步线性回归方法反演植被生化组分含量,从而达到监测植被生长状况的目的^[2]。本文具体介绍了多元逐步线性回归方法,及其在氮、木质素和纤维素含量估算中的应用。  相似文献