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    Accounting for systematic influences on preference heterogeneity in air travel

    , Article Transportation Research Record ; Issue 2300 , 2012 , Pages 147-154 ; 03611981 (ISSN) Rezaei, A ; Puckett, S. M ; Sharif University of Technology
    2012
    Abstract
    Modeling passengers' itinerary choice behavior helps in understanding the increasingly competitive airline market and in predicting air travel demand. Recently, investigation of the variation in passengers' preferences with regard to factors influencing their choice through estimation of the mixed multinomial logit model has received attention. An extended form of the model identifies sources of heterogeneity and consequently makes the choice models less restrictive in considering both systematic and random preference variation across individuals. This research investigates the existence of significant interactions between passengers' preference heterogeneity around the mean of random... 

    An integrated model for prediction of thermo-mechanical behaviour of metal and work-rolls during hot strip rolling process

    , Article Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture ; Volume 223, Issue 4 , 2009 , Pages 395-407 ; 09544054 (ISSN) Rezaei Farkoosh, A ; Serajzadeh, S ; Sharif University of Technology
    2009
    Abstract
    In this paper an integrated model has been developed that is capable of considering the effects of process parameters on the thermo-mechanical behaviour of the work-roll and the strip during hot rolling operations. The commercially finite element package ABAQUS is utilized to solve the governing equations, while an elasto-viscoplastic material behaviour is utilized in the model. The model may be employed in single-pass as well as multi-pass rolling layouts. Various aspects of the hot rolling process are predicted including temperature field and thermo-mechanical stresses within the work-roll as well as temperature, strain, and residual stresses distributions within the strip. To assess the... 

    Analysis of oscillations in relay feedback systems with fractional-order integrating plants

    , Article Journal of Computational and Nonlinear Dynamics ; Volume 12, Issue 5 , 2017 ; 15551415 (ISSN) Rezaei, D ; Tavazoei, M. S ; Sharif University of Technology
    2017
    Abstract
    Oscillatory behavior and transfer properties of relay feedback systems with a linear plant including a fractional-order integrator are studied in this paper. An expression for system response in the time domain is obtained by means of short memory principle, Poincare return map, and Mittag-Leffler functions. On the basis of this expression, the frequency of self-excited oscillations is approximated. In addition, the locus of perturbed relay system (LPRS) is derived to analyze the input-output properties of the relay system. The presented analysis is supported by a numerical example. Copyright © 2017 by ASME  

    Oscillatory condition and invariant sets in fractional order relay feedback systems

    , Article 27th Iranian Conference on Electrical Engineering, ICEE 2019, 30 April 2019 through 2 May 2019 ; 2019 , Pages 1097-1101 ; 9781728115085 (ISBN) Rezaei, D ; Tavazoei, M. S ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Abstract
    In this paper, an oscillatory condition is obtained for fractional order relay feedback systems. This condition is derived by time domain representation of the response of the fractional order relay feedback system on the basis of the Mittag-Leffler functions. Also, using an inequality, which has been recently proved for fractional derivative of convex Lyapunov functions, an invariant set is found for the under-study fractional order relay feedback system. The obtained results are validated by numerical examples  

    Implementation of heart rate variability signal processing into FPGA: System on-chip design

    , Article Computing in Cardiology, Zaragoza, Spain ; Volume 40 , Sept , 2013 , Pages 397-400 ; 23258861 (ISSN); 9781479908844 (ISBN) Rezaei, S ; Moharreri, S ; Ajorloo, H ; Salavatian, S ; Sharif University of Technology
    2013
    Abstract
    In this paper, we try to develop and implement the HRV signal processing into a Field Programmable Gate Array (FPGA) for extracting this signals feature  

    Language identity among Iranian English language learners: a nationwide survey

    , Article Journal of Multilingual and Multicultural Development ; Vol. 35, Issue. 5 , 2014 , pp. 527-536 ; ISSN: 01434632 Rezaei, S ; Khatib, M ; Baleghizadeh, S ; Sharif University of Technology
    2014
    Abstract
    The present study is a nationwide survey of language identity among English language learners in Iran. The participants who completed the survey in this research included 1851 English language learners from different parts of the country who belonged to different genders, age groups and English language proficiency levels. The main instrument was a validated questionnaire which included 19 items and was administered online and by hand. The results of this survey revealed that Iranian English language learners had a moderate level of language identity and there was no significant difference between the language identity of male and female participants. In addition, the results indicated that... 

    A numerical study on the influence of interface recombination on performance of carbon nanotube/GaAs solar cells

    , Article Optical and Quantum Electronics ; Volume 48, Issue 8 , 2016 ; 03068919 (ISSN) Movla, H ; Ghaffari, S ; Rezaei, E ; Sharif University of Technology
    Springer New York LLC  2016
    Abstract
    Carbon nanotubes (CNT) have unique electronic properties and remarkable optical properties. Despite of on layer thickness of CNTs, it has able to absorb photons from visible to far infrared and terahertz. These unique properties lets to create heterojunction devices by semiconductor/CNTs or metal/CNTs junctions e.g. photodiodes, sensor and heterojunction solar cell. The CNTs can play the role of a heterojunction component for charge separation as a high conductive network for charge transport and as a transparent electrode for light illumination and charge collection. The main objective of the present article is to establish a relation between interface recombination and the characteristics... 

    A strategy for total recovery of residue from terephthalic acid production process

    , Article Russian Journal of Applied Chemistry ; Volume 88, Issue 7 , July , 2015 , Pages 1201-1206 ; 10704272 (ISSN) Rezaei, V ; Sajadi, S. A. A ; Sharif University of Technology
    Maik Nauka-Interperiodica Publishing  2015
    Abstract
    Terephthalic acid is generally produced via oxidation of p-xylene. In this process, a large quantity of residue is produced containing cobalt, manganese, and bromine catalysts as well as by-products such as benzoic acid. Our purpose is to totally recover this residue. Extraction by water has been used as an efficient method to recover catalyst from this residue. In this study, the best condition for extraction was obtained at water/residue dilution ratio of 6: 1, extraction temperature of 45°C and extraction time of 40 min. Efficiency of catalyst recovery was 92 wt % at these conditions. The catalyst containing extracted solution can be reused in the oxidation process after being... 

    Modification of weakly compressible smoothed particle hydrodynamics for preservation of angular momentum in simulation of impulsive wave problems

    , Article Coastal Engineering Journal ; Volume 51, Issue 4 , 2009 , Pages 363-386 ; 05785634 (ISSN) Ataie Ashtiani, B ; Mansour Rezaei, S ; Sharif University of Technology
    2009
    Abstract
    In this work, Weakly Compressible Smoothed Particle Hydrodynamics (WCSPH) is applied for numerical simulation of impulsive wave. Properties of linear and angular momentum in WCSPH formulation are studied. Kernel gradient of viscous term in momentum equation is corrected to ensure preservation of angular momentum. Corrected WCSPH method is used to simulate solitary Scott Russell wave and applied to simulate impulsive wave generated by two-dimensional under water landslide. In each of the test cases, results of corrected WCSPH are compared with experimental results. The results of the numerical simulations and experimental works are matched and a satisfactory agreement is observed.... 

    Stress intensity factors of multiple axisymmetric interface cracks in an isotropic layer with FGM coating under torsional loading

    , Article Multidiscipline Modeling in Materials and Structures ; Volume 15, Issue 6 , 2019 , Pages 1352-1365 ; 15736105 (ISSN) Tavakoli, A ; Pourseifi, M ; Rezaei, S ; Sharif University of Technology
    Emerald Group Publishing Ltd  2019
    Abstract
    Purpose: The purpose of this paper is to provide a theoretical analysis of the fracture behavior of multiple axisymmetric interface cracks between a homogeneous isotropic layer and its functionally graded material (FGM) coating under torsional loading. Design/methodology/approach: In this paper, the authors employ the distributed dislocation technique to the stress analysis, an FGM coating-substrate system under torsional loading with multiple axisymmetric cracks consist of annular and penny-shaped cracks. First, with the aid of the Hankel transform, the stress fields in the homogeneous layer and its FGM coating are obtained. The problem is then reduced to a set of singular integral equations... 

    The impact of computer-aided concept mapping on EFL learners' lexical diversity: A process writing experiment

    , Article ReCALL ; Volume 33, Issue 3 , 2021 , Pages 214-228 ; 09583440 (ISSN) Hassanzadeh, M ; Saffari, E ; Rezaei, S ; Sharif University of Technology
    Cambridge University Press  2021
    Abstract
    Nowadays, many second/foreign language (L2) academic writing instruction programs place a high premium on pre-writing strategies. The current study examined the effect of software-supported concept mapping on lexical diversity (LD) of English learners' argumentative essays within a process writing framework. Additionally, the relationship between the learners' LD and their overall writing quality was investigated. To this end, 53 university English as a foreign language (EFL) undergraduates were assigned to a computer-aided concept mapping (CACM) and a traditional outlining condition over a span of seven weeks. The CACM group was instructed through the graphic organizer software... 

    Values and identities in Iranian primary school social studies textbooks: a discursive approach

    , Article Journal of Beliefs and Values ; 2021 ; 13617672 (ISSN) Rezaei, S ; Abe, S ; Farhang, A ; Sharif University of Technology
    Routledge  2021
    Abstract
    Textbooks provide the most serious source of knowledge construction and transmission for children at schools. This paper used a discursive and qualitative content analysis approach to extract the dominant values, ideologies and identities in four social studies textbooks taught nationwide to children in primary schools in Iran. Textual and visual analysis were applied on these textbooks and the results showed the saliency of four dominant discourses and values including pre-Islamic ethos and Iranian-Islamic identity, war and peace, social and traditional values in Iranian culture, and respect for diversity. Each of these discourses are discussed and some recommendations are made at the end... 

    Values and identities in Iranian primary school social studies textbooks: a discursive approach

    , Article Journal of Beliefs and Values ; Volume 43, Issue 4 , 2022 , Pages 396-413 ; 13617672 (ISSN) Rezaei, S ; Abe, S ; Farhang, A ; Sharif University of Technology
    Routledge  2022
    Abstract
    Textbooks provide the most serious source of knowledge construction and transmission for children at schools. This paper used a discursive and qualitative content analysis approach to extract the dominant values, ideologies and identities in four social studies textbooks taught nationwide to children in primary schools in Iran. Textual and visual analysis were applied on these textbooks and the results showed the saliency of four dominant discourses and values including pre-Islamic ethos and Iranian-Islamic identity, war and peace, social and traditional values in Iranian culture, and respect for diversity. Each of these discourses are discussed and some recommendations are made at the end... 

    Evaluating valence level of pictures stimuli in heart rate variability response

    , Article 42nd Computing in Cardiology Conference, CinC 2015, 6 September 2015 through 9 September 2015 ; Volume 42 , 2015 , Pages 1057-1060 ; 23258861 (ISSN); 9781509006854 (ISBN) Rezaei, S ; Moharreri, S ; Jafarnia Dabanloo, N ; Parvaneh, S ; Sharif University of Technology
    IEEE Computer Society  2015
    Abstract
    Low and high valence were induced in 20 male volunteers using two groups of pictures stimuli. Heart response was compared between two groups from RR series extracted from recorded ECG measurements. Mean heart rate and heart rate variability measures including time, frequency and Poincare domain were extracted. The results revealed that HRV triangular index, SDNN and SD2 were the only statistically significant parameters between groups (p<0.05). Mean heart rate and power in LF and HF bands were also different between low and high valence groups however level of significance was not reached. © 2015 CCAL  

    Heterogeneity in preferences of air travel itinerary in a low-frequency market

    , Article Transportation Research Record ; Issue 2214 , 2011 , Pages 10-19 ; 03611981 (ISSN) Rezaei, A ; Puckett, S. M ; Nassiri, H ; Sharif University of Technology
    2011
    Abstract
    Research in the choice behavior of air travelers has evolved to include an analytical focus on variation in the sensitivities of travelers to factors influencing itinerary choice. Some choice studies have moved beyond a focus on assumed representative, mean-level sensitivities toward a goal of representing the distribution of preferences across a sample. The mixed multinomial logit model has served as a valuable means of estimating such distributions of air travel preferences, including studies of business travelers, impacts of airport level-of-service attributes, distributions of willingness-to-pay (WTP), and information-processing strategies. Does the insight gained in previous studies,... 

    Iranian doctoral students’ shared experience of English-medium publication: the case of humanities and social sciences

    , Article Higher Education ; Volume 80, Issue 2 , Desember , 2020 , Pages 255-271 Mansouri Nejad, A ; Qaracholloo, M ; Rezaei, S ; Sharif University of Technology
    Springer  2020
    Abstract
    The present study was an attempt to explore international English-medium publication in humanities and social sciences in Iran. In so doing, 50 PhD students from 8 humanities and social sciences disciplines, who had already published or attempted to publish in English-medium journals, were requested to write reflection guide accounts and to take part in follow-up semi-structured interviews. The reflection guide and interview data were analyzed based on the principles of grounded theory research yielding the four major themes of motivations, hurdles, strategies, and call for support. The results indicated that the Iranian PhD students in the fields of humanities and social sciences are... 

    Performance analysis of per tone equalization in DMT-based systems

    , Article Scientia Iranica ; Volume 13, Issue 4 , 2006 , Pages 355-363 ; 10263098 (ISSN) Changiz Rezaei, S. S ; Pakravan, M. R ; Sharif University of Technology
    Sharif University of Technology  2006
    Abstract
    The Per Tone equalization algorithm is a novel discrete multitone (DMT) equalization method with practical applications in subscriber digital loop systems. Unlike time domain DMT equalizers (TEQ), which equalize all DMT tones in a combined fashion, the Per Tone equalizer equalizes each tone separately. In this paper, the performance and complexity of this technique is investigated and compared with that of other TEQs. Furthermore, the behavior of this technique in different simulation conditions, such as over different standard CSA loops and in the presence of additive white Gaussian noise with variable power spectral density level and near end crosstalk (NEXT), is studied and compared with... 

    Per Tone equalization analysis in DMT based systems

    , Article IEEE TENCON 2004 - 2004 IEEE Region 10 Conference: Analog and Digital Techniques in Electrical Engineering, Chiang Mai, 21 November 2004 through 24 November 2004 ; Volume A , 2004 , Pages A539-A542 Rezaei, S. S. C ; Pakravan, M. R ; IEEE Region 10 ; Sharif University of Technology
    2004
    Abstract
    Time domain equalizers are used in the receiver of a discrete multitone (DMT) receiver to compensate the channel effects on the received signal. There are a lot of DMT equalization algorithms presented in the literature, but recently a novel Per Tone equalizer structure was proposed which offers some advantages over the previous traditional ones. The objective of this paper is to provide an overview of the important concepts of this technique and evaluate its initialization complexity. The performance of this technique is also compared with typical time-domain equalization algorithms in different simulation environments. © 2004IEEE  

    Estimation of the kinetic parameters of processes at the negative plate of lead-acid batteries by impedance studies

    , Article Journal of Power Sources ; Volume 195, Issue 17 , September , 2010 , Pages 5789-5793 ; 03787753 (ISSN) Rezaei Niya, S. M ; Hejabi, M ; Gobal, F ; Sharif University of Technology
    2010
    Abstract
    Impedance characteristics of the negative electrode of lead-acid battery were derived on the basis of fundamental interfacial processes occurring at the electrode. The solution of the governing equations was presented in terms of a simple equivalent circuit consisting of resistive and capacitive loops in which charge transfer and sulfate layer formation and also mass transfer (Warburg) elements are considered. The kinetic parameters were deduced by fitting the theoretically derived impedance to the experimental data. Impedance at various States of Charge (SoC) was also examined  

    The effect of dispersed phase salinity on water-in-oil emulsion flow performance: A micromodel study

    , Article Industrial and Engineering Chemistry Research ; Volume 56, Issue 15 , 2017 , Pages 4549-4561 ; 08885885 (ISSN) Maaref, S ; Ayatollahi, S ; Rezaei, N ; Masihi, M ; Sharif University of Technology
    American Chemical Society  2017
    Abstract
    In this work, the effect of brine salinity on water-in-oil emulsion flow performance in porous media is studied as it imposes a significant challenge to oil production in the petroleum industry. A crude oil sample from an Iranian oilfield and synthetic brine with different salinities (40-140 g/L salt) are used. The results show that the emulsion viscosity and interfacial tension increase slightly with salinity, while they do not considerably affect the flow behavior. The emulsion stability analysis shows that larger w/o emulsion droplets are formed for higher brine salinity, which potentially block more pore spaces through straining and interception mechanisms. This phenomenon resulted in...