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971.
阐述了遗传算法的基本原理,提出了与马尔柯夫随机场相结合的遗传算法在影像纹理分类中的应用。通过对4种纹理取样的实验,表明这种影像纹理分类方法可以提高分类的正确率。 相似文献
972.
A. Tu
rul 《Engineering Geology》1998,50(3-4):337-345
The Atatürk dam was built across the Firat River on clayey limestone. A grout curtain, providing impermeability in the left and right abutments, was done in grouting galleries. The well known rock mass classification systems for tunneling purposes [rock structure rating (RSR), rock mass rating (RMR) and rock mass quality index (Q)] were used to classify the rock mass along these galleries. Based on RSR, RMR and Q values, the rock masses in the galleries have been classified into three different classes. Correlation between the three classification systems is discussed and suggestions are made for using rockbolt, shotcrete with wiremesh and steel ribs for supporting the rock mass. 相似文献
973.
Landslide zoning in a part of the Garhwal Himalayas 总被引:21,自引:1,他引:20
The Himalayas are undergoing constant rupturing in the thrust belt zone in the Garhwal Himalayas, due to which earthquake
and mass movement activity is triggered. These processes of mass movement and landslides have been constantly modifying the
landscape. Landslides are one of the indicators of the geomorphological modifications taking place in this active and fragile
terrain. This work is aimed at providing another example of landslide susceptibility mapping based on geological and geomorphological
attributes. The data collected from aerial photographs, topographic sheets and the image suggests that there is a correlation
between the distribution of landslides and some of the geological and geomorphological factors, for example, the distance
from an active fault, relative relief and slope. Parameters like factor of safety, altitude, relief, slope and the distance
from the fault lineament have been included in the study. A rating system has been applied to the factors for arriving at
a quantitative estimate of landslide susceptibility for each physiographic unit. Since terrain classification forms the foundation
of this work, the entire study can be grouped into two sequential activities: (1) the terrain classification and (2) landslide
susceptibility mapping. The result is the landslide susceptibility zoning map presented. The landslides have not been classified
with respect to time and may represent the final result of the on-going geological, geomorphological and seismic activity
since the Holocene period or late Pleistocene time when the glaciers retreated.
The area chosen for the study lies between Badri gad and Barni gad in Yamuna valley region of the Garhwal Himalaya where a
very large scale investment is in the pipe line for Hydroelectric power generation.
Received: 12 August 1993 · Accepted: 13 January 1998 相似文献
974.
塔中地良奥陶系地层格架与沉积演化 总被引:1,自引:0,他引:1
塔里木中部地区奥陶系大致以Ⅰ号断裂为界分东北和西南两个地层分区,自下而上分白云岩段、灰岩段、泥质灰岩段、泥岩夹灰岩段、泥岩夹砂岩段、砂砾岩段、泥岩夹砂岩段、泥岩灰岩互层段和砂岩段等9个岩性段。早奥陶世,塔中地区以碳酸盐岩台地相为主,自西向东为局限台地相、开阔台地相、台地边缘相和深水斜坡相。中——晚奥陶世,塔中地区西部以混积陆架相为主,东部以深水斜坡相为主。中—晚奥陶世,塔中东部及塔东地区在构造上具弧后前陆盆地性质。中—上奥陶统地层完整地记录了该盆地从形成发展到消亡的过程,即早期为深水斜坡相复理石活动沉积,晚期演化为浅海陆架相稳定沉积。 相似文献
975.
The purpose of this project was to develop and test a methodology for determining the likelihood that mineral resource location
records from two nationwide mineral resource information databases represent the same site. The long-term goal is to create
a comprehensive database by merging the Mineral Resource Data System (MRDS) of the U.S. Geological Survey, and the Mineral
Availability System/Mineral Industry Location System (MAS/MILS) of the U.S. Bureau of Mines (now part of the Geological Survey).
Part of that process involves linking records for the same site from each database. Match probabilities were estimated using
a logistic regression of mineral resource location attributes, derived from known matched (cross-referenced) and known unmatched
randomly sampled mineral site pairs from within the conterminous United States (n=10,000). Model accuracy was assessed using a randomly sampled test dataset, not used in logistic model development (n=4,000). Probability distributions were similar between the development and test datasets. The overall agreement beyond chance
was good for the test data set
using the kappa statistic. Classification accuracy was 89.6% for known matched site pairs and 84.0% for known unmatched site
pairs based on a probability threshold of 0.50 for a match. Distributions of attributes were similar between the development
and test datasets. This classification method is a viable approach for estimating match probabilities between database records. 相似文献
976.
977.
白水峪水电站右岸坝下游边坡岩体的RMR-SMR分类及稳定性评价 总被引:6,自引:0,他引:6
本文简要介绍了边坡岩体分类的RMR-SMR系统。结合白水峪边坡, 通过自然历史分析和稳定性计算, 讨论了运用SMR系统进行边坡岩体分类的改进意见。 相似文献
978.
区域国土资源分等评价研究:以大连陆域国土资源为例 总被引:3,自引:0,他引:3
区域国土资源分等评价是价格评估的前期工作。文中以大连陆域国土资源分等评价为例,讨论了区域国土资源等级评定方法。 相似文献
979.
西北地区戈壁砂砾石场地的脉动特征 总被引:1,自引:0,他引:1
阐述了我国西北部戈壁砂砾石层的划分及其时代确定等问题,以近几年西北地区地震小区划和重大工程建设项目中的实际观测资料为依据,对西北戈壁滩砂砾石场地的脉动特征进行了分析和总结,在此基础上探讨了场地脉动频谱特性与场地有关参数的关系,同时还就地脉动测试在工程中的推广应用等问题提出了几点看法。 相似文献
980.
砂岩孔隙结构分维及其应用 总被引:7,自引:1,他引:7
分形几何学特别适合于解决复杂环境中的许多问题。本文把砂岩孔隙结构置于分形几何学框架内,推导了小于孔隙半径r的孔隙度与孔隙半径之间幂函数关系,表明其指数与孔隙结构分维(D)有关,用压汞曲线证实这种幂函数关系是客观存在的,提供了一种测量孔隙结构分维的方法。作者研究认为,孔隙结构分维(D)能定量表征砂岩的储集性能,并能反映砂岩孔隙结构的成因特征。D接近于2,砂岩储集性能极好;D接近于3,砂岩储集性能极差。不同成因的孔隙结构具有不同的分维,但相同或相似成因的孔隙结构的分维具有固定的范围。因此可用分维对砂岩孔隙结构进行分类和评价。实际应用效果较好。 相似文献