Evaluation of Air Pollution Trend Using GIS and RS Applications in South West of Iran     

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   

A practical and efficient numerical scheme for the analysis of steady state unconfined seepage flows     

Mohammad Hossein Bazyar  Adel Graili 《国际地质力学数值与分析法杂志》2012,36(16):1793-1812

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   

New Criterion for Lunar Crescent Visibility     

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   

An iteratively reweighted least-squares approach to adaptive robust adjustment of parameters in linear regression models with autoregressive and <Emphasis Type="Italic">t</Emphasis>-distributed deviations     

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   

Impacts of Depositional Facies and Diagenesis on Reservoir Quality: A Case Study from the Rudist-bearing Sarvak Formation, Abadan Plain, SW Iran     

Ali ASSADI  Javad HONARMAND  Seyed Ali MOALLEMI  Iraj ABDOLLAHIE-FARD 《《地质学报》英文版》2023,97(1):190-206

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   

A new empirical equation for predicting the maximum initial amplitude of submarine landslide-generated waves     

Sabeti  Ramtin  Heidarzadeh  Mohammad 《Landslides》2022,19(2):491-503

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   

Uncertainty quantification of landslide runout motion considering soil interdependent anisotropy and fabric orientation     

Ma  Guotao  Rezania  Mohammad  Mousavi Nezhad  Mohaddeseh  Hu  Xiewen 《Landslides》2022,19(5):1231-1247

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   

Effects of over-consolidation history on flow instability of clean and silty sands     

Lashkari  Ali  Shourijeh  Piltan Tabatabaie  Khorasani  Seyed Saeid Sahebkar  Irani  Nazanin  Rahman  Md. Mizanur 《Acta Geotechnica》2022,17(11):4989-5007

Acta Geotechnica - This article presents an experimental program under the constant volume condition to investigate the influence of over-consolidation on flow instability of clean and silty sand...  相似文献   

A probabilistic framework to make a decision on the post-earthquake functionality of bridges considering the damage,residual displacement,and aftershock     

Akbari  Sepideh  Khanmohammadi  Mohammad 《Bulletin of Earthquake Engineering》2022,20(2):1193-1218

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   

Reliability framework for characterizing heat wave and cold spell events     

Moghim  Sanaz  Jahangir  Mohammad Sina 《Natural Hazards》2022,112(2):1503-1525

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