نتایج جستجو برای: mean elevation
تعداد نتایج: 649647 فیلتر نتایج به سال:
Assessment of a DEM’s quality is usually undertaken by deriving a measure of DEM accuracy – how close the DEM’s elevation values are to the true elevation. Measures such as Root Mean Squared Error and standard deviation of the error are frequently used. These measures summarise elevation errors in a DEM as a single value. A more detailed description of DEM accuracy would allow better understand...
We study the accuracy of data on some local topographic attributes derived from digital elevation models (DEMs). First, we carry out a test for the precision of four methods for calculation of partial derivatives of elevations. We ® nd that the Evans method is the most precision algorithm of this kind. Second, we produce formulae for root mean square errors of four local topographic variables (...
It is investigated whether a GIS-based distributed model developed for rockfall assessment at slope scale, which uses data with a support of 2.562.5 m, could be used for rockfall assessment at the regional scale, using input data with a support of 25625 m and of poorer quality. It was anticipated that in the latter case the model error would increase. Three types of simulations were applied to ...
Background : Posterior corneal elevation changes are keys to early diagnosis of corneal ectasia after keratorefractive surgery, so it is important to use an accurate method for measuring posterior corneal elevation. The purpose of this study is investigating posterior corneal elevation changes with Pentacam(HR) on patients underwent photorefractive keratectomy. Methods: In this clinical tri...
purpose: to evaluate agreement between galilei, orbscan ii, and placido disk-based topography in terms of keratometry readings, and anterior and posterior elevation. methods: in this prospective comparative study, 184 eyes of 92 keratorefractive surgery candidates were evaluated with galilei, orbscan ii, and placido disk-based topography. keratometry readings and anterior and posterior elevatio...
An approach for regional low flow frequency analysis is to use multiple regression techniques for obtaining relationships between low flows with specific return periods and catchments characteristics. In this paper, this method has been used. After single-site frequency analysis for 20 stream gauging stations, homogeneity test was performed. Regional relationships between low flows with return ...
An approach for regional low flow frequency analysis is to use multiple regression techniques for obtaining relationships between low flows with specific return periods and catchments characteristics. In this paper, this method has been used. After single-site frequency analysis for 20 stream gauging stations, homogeneity test was performed. Regional relationships between low flows with return ...
هدف: بررسی همبستگی بین شاخصهای اندازه‌گیری شده توسط پنتاکم با Elevation Difference قرنیه در بیماران با کراتوکونوس خفیف و متوسط روش پژوهش: صد و پانزده چشم مبتلا به کراتوکونوس در مراحل مختلف بالینی مورد بررسی قرار گرفتند. Elevation difference سطح قدامی و خلفی قرنیه، از نقشه difference نمودار Belin Ambrosio enhance سیستم Scheimflug به دست آمد. شاخصهای K max, Thinnest point, Asphericity, Astigmat...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید