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Search Results: 1 - 10 of 34 matches for " Abazar Solgi "
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Forecasting Daily Precipitation Using Hybrid Model of Wavelet-Artificial Neural Network and Comparison with Adaptive Neurofuzzy Inference System (Case Study: Verayneh Station, Nahavand)
Abazar Solgi,Vahid Nourani,Amir Pourhaghi
Advances in Civil Engineering , 2014, DOI: 10.1155/2014/279368
Abstract: Doubtlessly the first step in a river management is the precipitation modeling over the related watershed. However, considering high-stochastic property of the process, many models are still being developed in order to define such a complex phenomenon in the field of hydrologic engineering. Recently artificial neural network (ANN) as a nonlinear interextrapolator is extensively used by hydrologists for precipitation modeling as well as other fields of hydrology. In the present study, wavelet analysis combined with artificial neural network and finally was compared with adaptive neurofuzzy system to predict the precipitation in Verayneh station, Nahavand, Hamedan, Iran. For this purpose, the original time series using wavelet theory decomposed to multiple subtime series. Then, these subseries were applied as input data for artificial neural network, to predict daily precipitation, and compared with results of adaptive neurofuzzy system. The results showed that the combination of wavelet models and neural networks has a better performance than adaptive neurofuzzy system, and can be applied to predict both short- and long-term precipitations. 1. Introduction Estimation and forecasting of precipitation and its runoff have played effective and critical role in the watershed management and proper utilization of watershed, dams, and reservoirs and finally minimizing the damage caused by floods and drought. Therefore, this subject is the hydrologist’s interest. Predicting any event forms the basis of crisis management, and when this goal can be achieved, the predicting model could be accessed. Several methods are used for predicting hydrological events such as precipitation. Using each of these methods is always with some error in results. Accurate prediction of hydrological signals such as precipitation can provide useful information to predict amount of precipitation for water resources and soil management in a basin. In addition, correct prediction of hydrological signals plays an important role in reducing the effects of drought on water resources systems. Hydrological systems are affected by many factors such as climate, land cover, soil infiltration rates, evapotranspiration which is dependent on stochastic components, multitemporal scales, and above-mentioned nonlinear characteristics. Despite nonlinear relationships, uncertainty, and high lack of precision and variables temporal and spatial characteristics in water circulation system, none of the statistical and conceptual models which are proposed for accurate precipitation and runoff modeling were
Constrained Nonlinear Model Predictive Control of a Polymerization Process via Evolutionary Optimization  [PDF]
Masoud Abbaszadeh, Reza Solgi
Journal of Intelligent Learning Systems and Applications (JILSA) , 2014, DOI: 10.4236/jilsa.2014.61004
Abstract:

In this work, a nonlinear model predictive controller is developed for a batch polymerization process. The physical model of the process is parameterized along a desired trajectory resulting in a trajectory linearized piecewise model (a multiple linear model bank) and the parameters are identified for an experimental polymerization reactor. Then, a multiple model adaptive predictive controller is designed for thermal trajectory tracking of the MMA polymerization. The input control signal to the process is constrained by the maximum thermal power provided by the heaters. The constrained optimization in the model predictive controller is solved via genetic algorithms to minimize a DMC cost function in each sampling interval.

A Study of the Relationship between Landslide and Active Tectonic Zones: A Case Study in Karaj Watershed Management  [PDF]
Rahman Sharifi, Ali Solgi, Mohsen Pourkermani
Open Journal of Geology (OJG) , 2013, DOI: 10.4236/ojg.2013.33027
Abstract:

This research shows a noticeable comparison between slide zones produced with the results using the Nilsen method with active tectonic hazard zonation map. A determination landform of geometry or morphometry factors is one of the best methods for study and evaluation active tectonics. The first image provided is a Dem maps from GIS software showing topography, geology and tectonic maps participant with field activities. The second image provided shows an active tectonic map also generated by the same above mentioned factors into three classes A, B, C, D and a landslide hazard zonation map which shows five classes: Stable zone, generally stable zone, stable moderately stable zone, moderately stable zone and talented to liquefaction zone. The study and comparison and conformity landslide hazard zonation map with hazard zonations into active tectonic hazard zonation map showed about 79 percent (56,880 hectare) moderately unstable zone and talented for liquefaction zone settled in A zone (very high tectonic activity) and B zone (high tectonic activity) active tectonic map and 21 percent (15,130 hectare) remain unsettled sequential 12 percent (8640 hectare) and 9 percent (6480 hectare) in C (moderate tectonic activity), D (lowest tectonic activity) zone of active tectonic hazard zonation produced from above mentioned factors. This research showed a relationship between slide zones produced in landslide hazard zonations using the Nilsen method to measure active tectonic hazard zonation in the study region.

Landslide Zoning in Amir-Almoemenin (AS) Water Supply Pipeline Complex, North Khorasan  [PDF]
Bizhan Shirdel, Ali Sorbi, Ali Solgi
Open Journal of Geology (OJG) , 2016, DOI: 10.4236/ojg.2016.61001
Abstract: Landslide term is used for all mass movements on slopes, including falling, overturns and flow debris. Using the potential landslide hazard zonation, areas with high potential of landslide hazard can be detected and so prevent the landslide occurrence with providing appropriate solutions. In this study, the landslide hazard zonation along the water transmission lines of the Amir-Almomenin (AS) water supply complex has been done. Studied area is located at the western part of the Northern Khorasan (Bojnord). Study procedure includes the general geology survey, recognition of the most important effective parameters on the landslide phenomena (such as slope, lithology, faults and streams) and has been evaluated as basic maps. Then, each layer was validated based on the importance of the effective factors using the maps weighting method in ArcGis software. Finally, the studied area was zoned based on the landslide potential using the overlapping of the various layers. Final zonation map shows that the North, Northwestern and Median parts of the studied area have the highest landslide potential. These areas are included of Marl and red Marl and to some extend loss deposits with slopes between 14 to more of 50 degrees. Seemingly, faults (due to low occurrence) and streams (due to drought) have lower effect on the landslide potential. However, the degree of the slope and type of lithology are the most important parameters on the landslide potential, respectively.
Size Exclusion Mechanism, Suspension Flow through Porous Medium  [PDF]
Hooman Fallah, Afrouz Fallah, Abazar Rahmani, Mohammad Afkhami, Ali Ahmadi
International Journal of Modern Nonlinear Theory and Application (IJMNTA) , 2012, DOI: 10.4236/ijmnta.2012.14017
Abstract:

A lot of investigations have been done in order to understand the mechanisms of the transport of particulate suspension flow through porous medium. In general, Deep Bed Filtration studies have been conducted to analyse the mechanism involved in the processes of capturing and retaining particles occurs throughout the entire depth of the filter and not just on the filter surface. In this study, the deep bed filtration mechanism and the several mechanisms for the capture of suspended particles are explained then the size exclusion mechanism has been focused (particle capture from the suspension by the rock by the size exclusion). The effects of particle flux reduction and pore space inaccessibility due to selective flow of different size particles will be included in the model for deep bed filtration. The equations for particle and pore size distributions have been derived. The model proposed is a generalization of stochastic Sharma-Yortsos equations. Analytical solution for low concentration is obtained for any particle and pore size distributions. As we will see, the averaged macro scale solutions significantly differ from the classical deep bed filtration model.

RETRACTED: Investigation of Relation Vegetation and Some Soil Physico-Chemical Characteristics in Three Rangeland Habitats  [PDF]
Behnam Bahrami, Ardavan Ghorbani, Mohammad Jafari, Fereidoun Rezanezhad, Abazar Esmali
Open Journal of Ecology (OJE) , 2017, DOI: 10.4236/oje.2017.75024
Abstract: Short Retraction Notice


The authors want to retract the paper for his own reason.

This article has been retracted to straighten the academic record. In making this decision the Editorial Board follows COPE's Retraction Guidelines. The aim is to promote the circulation of scientific research by offering an ideal research publication platform with due consideration of internationally accepted standards on publication ethics. The Editorial Board would like to extend its sincere apologies for any inconvenience this retraction may have caused.

Please see the article page for more details. The full retraction notice in PDF is preceding the original paper which is marked \"RETRACTED\".

Assessing Site Disturbance Using Two Ground Survey Methods in a Mountain Forest
Akbar Najafi,Ahmad Solgi
Croatian Journal of Forest Engineering , 2010,
Abstract: Assessment of disturbance can provide forest managers with information to make appropriate decisions on site rehabilitation and monitoring. This paper evaluates the accuracy of successive estimates of site disturbance using two ground survey methods. The results from the point transect and grid point transect and grid point intercept methods were compared with the results from an intensive 1x1 m grid survey over a 4 ha study area. The point transect method, using a transect spacing of 30 m, provided the most accurate and consistent estimate of disturbance in the study area. Following the harvest, approximately half of all treated area was disturbed to varying levels. Intact forest floor (undisturbed) and light slash were the dominant surface conditions, covering an average of 70% of harvested area. The results indicate that shallow disturbances (litter left in place or removed) were more frequent than deep disturbances (topsoil removed, subsoil exposed, or rut exposed).
Investigating of Residual Tree Damage During Ground-Based Skidding
Ahmad Solgi,Akbar Najafi
Pakistan Journal of Biological Sciences , 2007,
Abstract: The study aims assessed the damages caused by skidding compared with the damages reported in other logging and skidding studies. Skidding had been conducted using cable skidders. After finishing the skidding operations, a field survey was done to collect data of all residual trees (species, DBH, height) and of tree wounds (size class, location and intensity of damage). Two types of damages were recorded: scarring and root damage. Results show that approximately 80% of the residual trees were damaged and that 52% of the residual trees have been affected by at least one new damage.
Statistical analysis of the price index of Tehran Stock Exchange
A. Rasoolizadeh,R. Solgi
Physics , 2004,
Abstract: This paper presents a statistical analysis of Tehran Price Index (TePIx) for the period of 1992 to 2004. The results present asymmetric property of the return distribution which tends to the right hand of the mean. Also the return distribution can be fitted by a stable Levy distribution and the tails are very fatter than the gaussian distribution. We estimate the tail index of the TePIx returns with two different methods and the results are consistent with the previous studies on the stock markets. A strong autocorrelation has been detected in the TePIx time series representing a long memory of several trading days. We have also applied a Zipf analysis on the TePIx data presenting strong correlations between the TePIx daily fluctuations. We hope that this paper be able to give a brief description about the statistical behavior of financial data in Iran stock market.
Constrained Nonlinear Model Predictive Control of an MMA Polymerization Process via Evolutionary Optimization
Masoud Abbaszadeh,Reza Solgi
Mathematics , 2015,
Abstract: In this work, a nonlinear model predictive controller is developed for a batch polymerization process. The physical model of the process is parameterized along a desired trajectory resulting in a trajectory linearized piecewise model (a multiple linear model bank) and the parameters are identified for an experimental polymerization reactor. Then, a multiple model adaptive predictive controller is designed for thermal trajectory tracking of the MMA polymerization. The input control signal to the process is constrained by the maximum thermal power provided by the heaters. The constrained optimization in the model predictive controller is solved via genetic algorithms to minimize a DMC cost function in each sampling interval.
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