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11.
Abolfazl Abdollahi Hamid Reza Riyahi Bakhtiari Mojgan Pashaei Nejad 《Journal of the Indian Society of Remote Sensing》2018,46(3):423-430
Currently, methods of extracting spatial information from satellite images are mainly based on visual interpretations and drawing the consequences by human factor, which is both costly and time consuming. A large volume of data collected by satellite sensors, and significant improvement in spatial and spectral resolution of these images require the development of new methods for optimal use of these data in order to produce rapid economic and updating road maps. In this study, a new automatic method is proposed for road extraction by integrating the SVM and Level Set methods. The estimated probability of classification by SVM is used as input in Level Set Method. The average of completeness, correctness, and quality was 84.19, 88.69 and 76.06% respectively indicate high performance of proposed method for road extraction from Google Earth images. 相似文献
12.
Farhadian Ali Ghasemi Ebrahim Hoseinie Seyed Hadi Bagherpour Raheb 《Geotechnical and Geological Engineering》2022,40(6):3343-3356
Geotechnical and Geological Engineering - Rock abrasivity index (RAI) and uniaxial compressive strength (UCS) are two key parameters for assessing abrasivity and durability of building stones,... 相似文献
13.
Summary This study attempts to find possible linkages between the NCP index and the winter temperature variability over Iran. The
investigation is based on statistical analysis of simple, partial and multiple correlations and also evaluation of composite
maps of the extreme NCP index and maps of correlation between atmospheric variables and the temperature time series.
Our results show that the NCP has a strong negative correlation with the winter temperature in Iran. Furthermore, combination
of both the NCP and the AO (Arctic Oscillation) indices improve the correlations in all stations, implying both NCP and AO
can be considered as major patterns for explaining the Iranian winter temperature variability. The results show that the positive
NCP is associated with enhanced precipitation and cloudy conditions, consequently causing below normal temperature over Iran.
The anomalies of OLR in this phase are also negative, implying a cloudy sky. For the negative NCP phase these results are
completely reversed. The correlation maps indicate that the NCP is negatively/positively correlated with winter Outgoing Long-wave
Radiation/precipitation over Iran. The results also show that the SLP and GPH patterns are quite different for the positive
and negative NCP phases over Iran. During the negative NCP a small cyclone is formed over the Arabian Sea causing a strong
easterly towards Iran. During the positive NCP this cyclone is removed. Our results show that for the positive NCP years an
upper-level trough is formed over northern Iran and the eastern Mediterranean. For the negative NCP years this trough becomes
weak and is located over central European regions. This trough is closely linked with the winter temperature over Iran. This
is expressed by a high correlation between 500-hPa geopotential height at this region and Iranian winter temperature.
Authors’ addresses: A. R. Ghasemi, Climate Research Center, Water Engineering Department, Agricultural Faculty, Shiraz University,
Shiraz, Iran; D. Khalili, Water Engineering Department, Agricultural Faculty, Shiraz University, Shiraz, Iran. 相似文献
14.
Hamidreza Ramazi Mohammad Reza Hossein Nejad Aenollah Azizzadeh Firoozi 《Journal of the Geological Society of India》2009,74(2):260-266
This paper is devoted to application of SP, resistivity and mise-a-la-masse method in Khenadarreh (Arak, Iran) graphite deposit
exploration. Mise-a-la-masse method is one of the main geophysical exploration methods used to investigate conductive bodies
with outcrops on the surface or in exploratory pits. By integrating mise-a-la-masse results with other geoelectrical methods,
such as self-potential and resistivity surveys, useful results can be acquired. Powerful survey design, data processing and
interpretation methods can make geoelectrical surveying results more reliable. Here, we applied integrated geoelectrical methods
to explore the Khenadarreh-bala graphite deposit in the Sarband region of the Markazi province, Iran. We present a new and
simple method for processing and interpreting mise-a-la-masse data, which corrects for the effect of distance from the current
electrode in the conductive body. After correction, the residual potential values corresponded with the SP results and the
apparent resistivity pseudosections. The geophysical results were confirmed by drill holes in the study area. 相似文献
15.
Prediction of pile settlement using artificial neural networks based on standard penetration test data 总被引:4,自引:0,他引:4
F. Pooya Nejad Mark B. Jaksa M. Kakhi Bryan A. McCabe 《Computers and Geotechnics》2009,36(7):1125-1133
In recent years artificial neural networks (ANNs) have been applied to many geotechnical engineering problems with some degree of success. With respect to the design of pile foundations, accurate prediction of pile settlement is necessary to ensure appropriate structural and serviceability performance. In this paper, an ANN model is developed for predicting pile settlement based on standard penetration test (SPT) data. Approximately 1000 data sets, obtained from the published literature, are used to develop the ANN model. In addition, the paper discusses the choice of input and internal network parameters which were examined to obtain the optimum model. Finally, the paper compares the predictions obtained by the ANN with those given by a number of traditional methods. It is demonstrated that the ANN model outperforms the traditional methods and provides accurate pile settlement predictions. 相似文献
16.
Delineation of groundwater potential zones using remote sensing and GIS-based data-driven models 总被引:5,自引:0,他引:5
The rapid increase in human population has increased the groundwater resources demand for drinking, agricultural and industrial purposes. The main purpose of this study is to produce groundwater potential map (GPM) using weights-of-evidence (WOE) and evidential belief function (EBF) models based on geographic information system in the Azna Plain, Lorestan Province, Iran. A total number of 370 groundwater wells with discharge more than 10 m3s?1were considered and out of them, 256 (70%) were randomly selected for training purpose, while the remaining114 (30%) were used for validating the model. In next step, the effective factors on the groundwater potential such as altitude, slope aspect, slope angle, curvature, distance from rivers, drainage density, topographic wetness index, fault distance, fault density, lithology and land use were derived from the spatial geodatabases. Subsequently, the GPM was produced using WOE and EBF models. Finally, the validation of the GPMs was carried out using areas under the ROC curve (AUC). Results showed that the GPM prepared using WOE model has the success rate of 73.62%. Similarly, the AUC plot showed 76.21% prediction accuracy for the EBF model which means both the models performed fairly good predication accuracy. The GPMs are useful sources for planners and engineers in water resource management, land use planning and hazard mitigation purpose. 相似文献
17.
Abouzar Jafari Mohammad Reza Ghasemi Habib Akbarzadeh Bengar Behrooz Hassani 《Bulletin of Earthquake Engineering》2018,16(2):831-858
Self-centering rocking walls offer the possibility of minimizing repair costs and downtimes, and also nullify the residual drift after seismic events, thanks to their self-centering properties. In this paper, the effect of axial stress ratio on the behavior of monolithic self-centering rocking walls is investigated by utilizing a developed finite element model. To verify the validity of the finite element model, results and observed damage in the model are compared with those of a full-scale wall test. The axial stress ratio is varied from 0.024 to 0.30 while keeping the other structural parameters constant. For qualitative damage evaluation, the observed damage in the model compared with expected damage states of desired performance levels. In order to evaluate the incurred damage quantitatively, the amount of crushing and damage in the wall is calculated by utilizing several ratios (crushing ratio and damage ratio). Furthermore, seismic response factors (i.e., μ, R and Cd) are calculated for different axial stress ratio values. The obtained results showed that, in order to satisfy the requirements of desired performance levels, the maximum axial stress ratio should be approximately within the range of 0.10–0.15. In addition, the maximum overall damage ratio and crushing ratio are suggested to be less than 5%. For axial stress ratio higher than 0.15, the flag-shaped pattern of hysteresis curves completely disappeared and the variation of displacement ductility is less sensitive to axial stress ratio. Considering the maximum axial stress ratio limited to 0.150, values of 4 and 3.5 are conservatively proposed as a period-independent response modification factor and displacement modification factor of the investigated structural wall, respectively. 相似文献
18.
M. Nejad‐Asghar 《Astronomische Nachrichten》2011,332(6):631-636
It is believed that protostellar accretion disks are formed from nearly ballistic infall of molecular matter in rotating core collapse. Collisions of this infalling matter leads to formation of strong supersonic shocks, which if they cool rapidly, result in accumulation of that material in a thin structure in the equatorial plane. Here, we investigate the relaxation time of the protostellar accretion post‐shock gas using the smoothed particle hydrodynamics (SPH). For this purpose, a one‐dimensional head‐on collision of two molecular sheets is considered, and the time evolution of the temperature and density of the post‐shock region simulated. The results show that in strong supersonic shocks, the temperature of the post‐shock gas quickly increases proportional to square of the Mach number, and then gradually decreases according to the cooling processes. Using a suitable cooling function shows that in appropriate time‐scale, the center of the collision, which is at the equatorial plane of the core, is converted to a thin dense molecular disk, together with atomic and ionized gases around it. This structure for accretion disks may justify the suitable conditions for grain growth and formation of proto‐planetary entities (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
19.
Hesam Seyedin Reza HabibiSaravi Nasrin sayfouri Vahid Hoseini Djenab Fariba Ghasemi Hamedani 《Natural Hazards》2017,88(2):965-975
Flood is the most common disaster in the world and has acute or chronic health consequences including psychological sequels. Post-traumatic stress disorder (PTSD) is one of the main consequences. This study aimed to explore the psychological impacts (PTSD) in two flooded cities of Mazandaran Province, Neka and Behshahr, in the southeastern Caspian region that experienced flooding in 2012. A cross-sectional community-based study was performed on randomly selected samples of 400 individuals using GIS-based sampling from 139931 residents of the two flooded cities. The PTSS-10 questionnaire was used for data collection. The results showed that the overall stress disorder mean score among the participants was 2.59 out of 6. PTSD prevalence in the affected population was 64%. It was also found that stress scores significantly increased in younger people, male gender, the divorced, the widows or the widowers, and those who lost their properties (p < 0.05). Study findings showed that flood is a considerable stressor which develops PTSD. This finding should be taken into account in all four phases of disaster management cycle, and subsequently, specialized post-disaster mental health services must be provided for the afflicted population. 相似文献
20.
Worldwide pesticide usage has increased dramatically during the last three decades, coinciding with changing practices and increasing by intensive agriculture. This widespread use of pesticides for agricultural and non‐agricultural purposes has resulted in the presence of their residues in various environmental matrices. The occurrence of pesticides and their metabolite transported in rivers, channels, lakes, sea, air, soils, groundwater, and even drinking water, proves the high risk of these chemicals to human health and the environment. Therefore, pesticide removal is of an increasing concern. In this study, a review of the published literature dealing with pesticides removal process is presented. Firstly, pesticide removal by conventional means is briefly considered. Secondly, the use of the low‐cost sorbent through biosorption process is discussed comprehensively. The effect of factors such as pH, contact time, sorbent dosage, initial pesticide concentration, and optimization of biosorption conditions is also discussed. Kinetic, thermodynamic, and mechanism studies are also given. This study shows that both microorganisms and other materials with biological origin like agricultural by‐products may be used to this end. There is a significant potential for pesticide uptake by the use of various pristine and especially modified biosorbents. In the case of living organisms used as removal agents, degradation may also play a role in the total removal observed. 相似文献