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71.
Mostafa Moradi Dashtpagerdi Seyed Javad Sadatinejad Rafat Zare Bidaki Ehsan Khorsandi 《Journal of the Indian Society of Remote Sensing》2014,42(1):179-186
In this paper, remote sensing and GIS have been used to assess the status of NO2 at the south west of Iran. 221 data about concentration of NO2 was extracted from Ozone Monitoring Instrument. Ordinary kriging and inverse distance weighting interpolation methods was used to interpolate data. Results showed that ordinary kriging method using cross-validation have had less error. North east of the study area has the highest concentration of NO2 (329 molecule/cm2) and the concentration of NO2 decreases from north east to South west of the study area. On the other hand, data trend results showed that the data seems to exhibit a fairly strong trend in the east west direction and a weaker one in the north–south direction. 相似文献
72.
A practical and efficient numerical scheme for the analysis of steady state unconfined seepage flows
The scaled boundary finite‐element method (SBFEM), a novel semi‐analytical technique, is applied to the analysis of the confined and unconfined seepage flow. This method combines the advantages of the finite‐element method and the boundary element method. In this method, only the boundary of the domain is discretized; no fundamental solution is required, and singularity problems can be modeled rigorously. Anisotropic and nonhomogeneous materials satisfying similarity are modeled without additional efforts. In this paper, SBFE equations and solution procedures for the analysis of seepage flow are outlined. The accuracy of the proposed method in modeling singularity problems is demonstrated by analyzing seepage flow under a concrete dam with a cutoff at heel. As only the boundary is discretized, the variable mesh technique is advisable for modeling unconfined seepage analyses. The accuracy, effectiveness, and efficiency of the method are demonstrated by modeling several unconfined seepage flow problems. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
73.
Mohammad Sh. Odeh 《Experimental Astronomy》2004,18(1-3):39-64
A new criterion for lunar crescent visibility has been established using 737 observations, almost half of them obtained by
the Islamic Crescent Observation Project (ICOP). This criterion is based on two variables, viz. the topocentric arc of vision
and the topocentric crescent width. The new model is able to predict the visibility of the lunar crescent both for naked eye
and optically aided observations. From the database we found a Danjon limit of 6.4 degrees.
Vice-President of “Crescents, Calendars and Mawaqeet Committee” of AUASS. 相似文献
74.
Boris Kargoll Mohammad Omidalizarandi Ina Loth Jens-André Paffenholz Hamza Alkhatib 《Journal of Geodesy》2018,92(3):271-297
In this paper, we investigate a linear regression time series model of possibly outlier-afflicted observations and autocorrelated random deviations. This colored noise is represented by a covariance-stationary autoregressive (AR) process, in which the independent error components follow a scaled (Student’s) t-distribution. This error model allows for the stochastic modeling of multiple outliers and for an adaptive robust maximum likelihood (ML) estimation of the unknown regression and AR coefficients, the scale parameter, and the degree of freedom of the t-distribution. This approach is meant to be an extension of known estimators, which tend to focus only on the regression model, or on the AR error model, or on normally distributed errors. For the purpose of ML estimation, we derive an expectation conditional maximization either algorithm, which leads to an easy-to-implement version of iteratively reweighted least squares. The estimation performance of the algorithm is evaluated via Monte Carlo simulations for a Fourier as well as a spline model in connection with AR colored noise models of different orders and with three different sampling distributions generating the white noise components. We apply the algorithm to a vibration dataset recorded by a high-accuracy, single-axis accelerometer, focusing on the evaluation of the estimated AR colored noise model. 相似文献
75.
An integrated geological-petrophysical analysis of the rudist-bearing sequence of the Cretaceous Sarvak Formation is given one giant oilfield, and provides an improved understanding of this main reservoir in the Abadan Plain, in the Zagros Basin, SW Iran. The main objective of this study is to evaluate reservoir potential of the Sarvak Formation, and then to utilize the calibrated well log signature to correlate reservoir potential in un-cored wells. Eight main facies are recognized and categori... 相似文献
76.
Landslides - The accurate prediction of landslide tsunami amplitudes has been a challenging task given large uncertainties associated with landslide parameters and often the lack of enough... 相似文献
77.
Landslides - Natural soils often exhibit an anisotropic fabric pattern as a result of soil deposition, weathering, or filling. This paper aims to investigate the effect of soil interdependent... 相似文献
78.
Bulletin of Earthquake Engineering - Making a decision on the post-earthquake functionality of structures has always been one of the most challenging issues in earthquake engineering. There is an... 相似文献
79.
Natural Hazards - Extreme weather events such as heat waves and cold spells affect people’s lives. This study develops a probabilistic framework to evaluate heat waves and cold spells. As... 相似文献
80.
Moosavi Seyed Amin Bakhtiari Hesam Aloki Honarmand Javad 《Geotechnical and Geological Engineering》2022,40(6):3225-3244
Geotechnical and Geological Engineering - This study examined the petrographically classification, petrological and petrophysical characteristics by taking a vast range of carbonate reservoir rock... 相似文献