...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Earth Surface Processes and Landforms: The journal of the British Geomorphological Research Group >A minimum sample size required from Schmidt hammer measurements
【24h】

A minimum sample size required from Schmidt hammer measurements

机译：施密特锤测量所需的最小样本量

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The Schmidt hammer is a useful tool applied by geomorphologists to measure rock strength in field conditions. The essence of field application is to obtain a sufficiently large dataset of individual rebound values, which yields a meaningful numerical value of mean strength. Although there is general agreement that a certain minimum sample size is required to proceed with the statistics, the choice of size (i.e. number of individual impacts) was usually intuitive and arbitrary. In this paper we show a simple statistical method, based on the two-sample Student's t-test, to objectively estimate the minimum number of rebound measurements. We present the results as (1) the 'mean' and 'median' solutions, each providing a single estimate value, and (2) the empirical probability distribution of such estimates based on many field samples. Schmidt hammer data for 14 lithologies, 13-81 samples for each, with each sample consisting of 40 individual readings, have been evaluated, assuming different significance levels. The principal recommendations are: (1) the recommended minimum sample size for weak and moderately strong rock is 25; (2) a sample size of 15 is sufficient for sandstones and shales; (3) strong and coarse rocks require 30 readings at a site; (4) the minimum sample size may be reduced by one-third if the context of research allows for higher significance level for test statistics. Interpretations based on less than 10 readings from a site should definitely be avoided.
机译：施密特锤是地貌学家用来测量野外条件下岩石强度的有用工具。现场应用的本质是获得足够大的单个回弹值数据集，这将产生有意义的平均强度数值。尽管人们普遍同意进行统计需要一定的最小样本量，但是选择大小（即单个影响的数量）通常是直观而随意的。在本文中，我们展示了一种基于两个样本的学生t检验的简单统计方法，可以客观地估算回弹测量的最小数量。我们将结果表示为（1）“均值”和“中位数”解决方案，每个解决方案均提供一个估计值，以及（2）基于许多现场样本的此类估计的经验概率分布。假设不同的显着性水平，已经对14种岩性的施密特锤数据进行了评估，每种13-81个样品，每个样品包含40个单独的读数。主要建议是：（1）对于弱和中等强度的岩石，建议的最小样本量为25; （2）砂岩和页岩的样本数量为15就足够了; （3）坚硬和粗糙的岩石需要在现场读取30个读数; （4）如果研究范围允许检验统计数据具有更高的显着性水平，则最小样本量可能会减少三分之一。绝对应避免基于站点的少于10个读数的解释。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号