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Search Results: 1 - 10 of 325518 matches for " S. Saadat "
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Primary analysis for enhancing the iron oxide and alteration minerals, using ETM+ data: a case study of Kuh-e-Zar gold deposit, NE Iran
S. Saadat,M. Ghoorchi
Iranian Journal of Earth Sciences , 2009,
Abstract: Different types of iron oxides deposits have been identified along the Khaf – Dorouneh volcanic and plutonic belt in north east of Iran. Kuh-e-Zar is one of these ore deposits known as Fe- oxide gold deposit. The main purpose of this paper is to detect and discriminate the iron oxide minerals in this area based on the ETM+ data. Data processing has been done by ENVI (Environment for Visualizing Images) software. Color Composites, Band Ratios, Principal Components (PC) analysis were used to delineate the associated zones of hydrothermal alteration and iron oxide minerals. Based on both field observations and the results of this satellite data processing, the area covered by secondary iron oxide (hematite, goethite and limonite mainly in soil) was enhanced very good, but the primary iron oxides (specularite) which are very fine grain and have a linear structure (mainly in mineralized veins) are not very clear in detail in these images.
Survey on Spam Filtering Techniques  [PDF]
Saadat Nazirova
Communications and Network (CN) , 2011, DOI: 10.4236/cn.2011.33019
Abstract: In the recent years spam became as a big problem of Internet and electronic communication. There developed a lot of techniques to fight them. In this paper the overview of existing e-mail spam filtering methods is given. The classification, evaluation, and comparison of traditional and learning-based methods are provided. Some personal anti-spam products are tested and compared. The statement for new approach in spam filtering technique is considered.
Nilpotent weights in conformal field theory
S. Rouhani,M. Saadat,Moghimi-Araghi
Iranian Journal of Physics Research , 2001,
Abstract: Logarithmic conformal field theory can be obtained using nilpotent weights. Using such scale transformations various properties of the theory were derived. The derivation of four point function needs a knowledge of singular vectors which is derived by including nilpotent variables into the Kac determinant. This leads to inhomogeneous hypergeometric functions. Finally we consider the theory near a boundary and also introduce the concept of superfields where a multiplet of conformal fields are dealt with together. This leads to the OPE of superfields and a logarithmic partner for the energy momentum tensor.
Petrochemical Characteristics of Neogene and Quaternary Alkali Olivine Basalts from the Western Margin of the Lut Block, Eastern Iran
S. Saadat,M. H. Karimpour,Ch. Stern
Iranian Journal of Earth Sciences , 2010,
Abstract: The Nayband strike-slip fault forms the western margin of the micro-continental Lut block in Eastern Iran. Neogene and Quaternary mafic volcanic rocks collected near Tabas, along the northern part of the fault (NNF; 15 Ma), and further to the south, along the middle part of the fault (MNF; 2 Ma), are within-plate sodic-series alkali olivine basalts with high TiO2 and up to >16% normative nepheline. Their high MgO, Ni and Cr contents indicate that they crystallized from relatively primitive magmas. Their low La/Nb and Ba/Nb ratios are similar to oceanic island basalts (OIB) and unlike convergent plate boundary arc basalts (IAB). These alkali olivine basalts show enrichment in LREE relative to HREE and limited variation in Sr, Nd and Pb isotopic values which all plot in the range of OIB. Ce/Pb (>39), Nb/U (44-120) and P2O5/K2O (~0.4) ratios suggest that crustal contamination was not significant for MNF basalts. The data may be interpreted as indicating the participation of upwelling mantle asthenosphere and the deeper continental mantle lithosphere in the generation of these basalts. They formed by generally low, but variable degrees of partial mantle melting, which decreased with time from 15 Ma NNF relative to2 Ma MNF basalts. The small volume of melts that formed the MNF basalts rose to the surface along the deep Nayband strike-slip fault with no interaction with the continental crust. The larger volume of NNF basalts interacted to some degree with the crust and are associated with basaltic andesites and andesites.
Two Approaches on Implementation of CBR and CRM Technologies to the Spam Filtering Problem  [PDF]
Rasim Alguliyev, Saadat Nazirova
Journal of Information Security (JIS) , 2012, DOI: 10.4236/jis.2012.31002
Abstract: Recently the number of undesirable messages coming to e-mail has strongly increased. As spam has changeable character the anti-spam systems should be trainable and dynamical. The machine learning technology is successfully applied in a filtration of e-mail from undesirable messages for a long time. In this paper it is offered to apply Case Based Reasoning technology to a spam filtering problem. The possibility of continuous updating of spam templates base on the bases of which new coming spam messages are compared, will raise efficiency of a filtration. Changing a combination of conditions it is possible to construct flexible filtration system adapted for different users or corporations. Also in this paper it is considered the second approach as implementation of CRM technology to spam filtration which is not applied to this area yet.
Air Pollution and In-Hospital Mortality of Ischemic Heart Disease Patients
S. Saadat,S. Sadeghian,R. Hamidian,M.A. Najafi
Journal of Biological Sciences , 2010,
Abstract: This study is aimed to evaluate the impact of air pollution on the in-hospital mortality of ischemic heart disease patients in Tehran as a polluted metropolis. A cross sectional study conducted in Tehran heart center. We compared two separate exposure levels of air pollutants in patients expired in hospital (n = 23) versus patients discharged alive (n = 1219). The first was air pollutants daily mean concentration at the date of admission and the second was air pollutants daily mean concentration at the date of admission and the three following days. Patients' demographic, clinical and paraclinical data were gathered from the hospital databank between 23 September and 21 December 2005. Meteorological data were obtained from Tehran air quality control company. In-hospital mortality rate was 1.9% for men and 1.8% for women. The expired patients were older than survived patients. The mean concentration of carbon monoxide, dust, nitrous oxide, other nitrogen compounds and sulfur dioxide were significantly higher and mean temperature was significantly lower at admission date of expired patients. In expired patients, mean concentrations of nitrous oxide, nitrogen dioxide, other nitrogen compounds, sulfur dioxide, dust and non-methane hydrocarbons were significantly higher at admission date and three following days compared to survived patients. There was significant direct relationship between air pollution level and in-hospital mortality of ischemic heart disease patients.
Use of Nilpotent weights in Logarithmic Conformal Field Theories
S. Moghimi-Araghi,S. Rouhani,M. Saadat
Physics , 2002, DOI: 10.1142/S0217751X03016914
Abstract: We show that logarithmic conformal field theories may be derived using nilpotent scale transformation. Using such nilpotent weights we derive properties of LCFT's, such as two and three point correlation functions solely from symmetry arguments. Singular vectors and the Kac determinant may also be obtained using these nilpotent variables, hence the structure of the four point functions can also be derived. This leads to non homogeneous hypergeometric functions. Also we consider LCFT's near a boundary. Constructing "superfields" using a nilpotent variable, we show that the superfield of conformal weight zero, composed of the identity and the pseudo identity is related to a superfield of conformal dimension two, which comprises of energy momentum tensor and its logarithmic partner. This device also allows us to derive the operator product expansion for logarithmic operators. Finally we discuss the AdS/LCFT correspondence and derive some correlation functions and a BRST symmetry.
On the AdS/CFT Correspondence and Logarithmic Operator
S. Moghimi-Araghi,S. Rouhani,M. Saadat
Physics , 2001, DOI: 10.1016/S0370-2693(01)01052-8
Abstract: Logarithmic conformal field theory is investigated using the AdS/CFT correspondence and a novel method based on nilpotent weights. Using this device we add ghost fermions and point to a BRST invariance of the theory.
Logarithmic Conformal Field Theory Through Nilpotent Conformal Dimensions
S. Moghimi-Araghi,S. Rouhani,M. Saadat
Physics , 2000, DOI: 10.1016/S0550-3213(01)00004-9
Abstract: We study logarithmic conformal field theories (LCFTs) through the introduction of nilpotent conformal weights. Using this device, we derive the properties of LCFT's such as the transformation laws, singular vectors and the structure of correlation functions. We discuss the emergence of an extra energy momentum tensor, which is the logarithmic partner of the energy momentum tensor.
Current Algebra Associated with Logarithmic Conformal Field Theories
S. Moghimi-Araghi,S. Rouhani,M. Saadat
Mathematics , 2000,
Abstract: We propose a general frame work for deriving the OPEs within a logarithmic conformal field theory (LCFT). This naturally leads to the emergence of a logarithmic partner of the energy momentum tensor within an LCFT, and implies that the current algebra associated with an LCFT is expanded. We derive this algebra for a generic LCFT and discuss some of its implications. We observe that two constants arise in the OPE of the energy-momentum tensor with itself. One of these is the usual central charge.
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