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    Rate adaptation and power allocation for time-correlated MISO Rayleigh fading channel with delay-limited HARQ

    , Article IEEE International Conference on Communications, 10 June 2012 through 15 June 2012 ; 2012 , Pages 3915-3919 ; 15503607 (ISSN) ; 9781457720512 (E-ISBN) Rastegar, S. H ; Vakilinia, S ; Khalaj, B. H ; Sharif University of Technology
    2012
    Abstract
    In this paper, we consider the problem of optimum rate adaptation and power allocation to maximize the delay-limited throughput (DLT) in a time-correlated 2×1 MISO Rayleigh fading channel with Hybrid ARQ in Chase-Combining mode (HARQ-CC). To this aim, we have first formulated the DLT equation based on the outage probability for 2×1 MISO-HARQ channel. We show that exact analytical calculation of the outage probability is not tractable. Therefore, we approximate the outage probability using a log-normal approximation approach. Based on such approximation, optimal rate and power allocations are derived. Finally, using Monte-Carlo simulation, we show that the approximation method provides... 

    Optimal in-home charge scheduling of plug-in electric vehicles incorporating customerメs payment and inconvenience costs

    , Article Power Systems ; Vol. 88, issue , 2014 , p. 301-326 ; ISSN: 16121287 Fotuhi-Firuzabad, M ; Shafiee, S ; Rastegar, M ; Sharif University of Technology
    2014
    Abstract
    Plug-in electric vehicles (PEVs) are identified as one of the motivating technologies in smart grid era. However, if their highly disruptive impacts on the distribution system are left unaddressed, it may obstruct both smart grid development and PEV adoption. This chapter develops a novel in-home PEV charging control (PCC) algorithm that schedules both the time and level of charging PEVs incorporating customerメs desired comfort level. This optimization-based problem attempts to achieve a trade-off between minimizing the electricity payment and minimizing the waiting time to fully charge the PEVs in presence of a time of use (TOU) pricing tariff combined with inclining block rates (IBRs). The... 

    Magnetic and electric field assisted electrospun polyamide nanofibers for on-line μ-solid phase extraction and HPLC

    , Article RSC Advances ; Vol. 4, Issue. 94 , 2014 , pp. 52590-52597 ; ISSN: 20462069 Bagheri, H ; Piri-Moghadam, H ; Rastegar, S ; Sharif University of Technology
    2014
    Abstract
    The effects of applied magnetic and electric fields on electrospinning were investigated to produce more efficient nanofibers. Considering the previous extensive studies, polyamide nanofibers were prepared by a conventional approach and under auxiliary electric and magnetic fields. The first sorbent was synthesized by electrospinning of a solution of 18% polyamide in formic acid. The second and third types of polyamide were prepared similarly while the electrospinning processes were assisted by an electric and a magnetic field. The third type of polyamide contained a magnetic ionic liquid (MIL) to induce sufficient magnetic susceptibility in the polymeric solution. The SEM images revealed... 

    Optimal in-home charge scheduling of plug-in electric vehicles incorporating customer’s payment and inconvenience costs

    , Article Power Systems ; Vol. 88, Issue. 1 , 2014 , pp. 301-326 ; ISSN: 1612-1287 Fotuhi-Firuzabad, M ; Shafiee, S ; Rastegar, M ; Sharif University of Technology
    2014
    Abstract
    Plug-in electric vehicles (PEVs) are identified as one of the motivating technologies in smart grid era. However, if their highly disruptive impacts on the distribution system are left unaddressed, it may obstruct both smart grid development and PEV adoption. This chapter develops a novel in-home PEV charging control (PCC) algorithm that schedules both the time and level of charging PEVs incorporating customer’s desired comfort level. This optimization-based problem attempts to achieve a trade-off between minimizing the electricity payment and minimizing the waiting time to fully charge the PEVs in presence of a time of use (TOU) pricing tariff combined with inclining block rates (IBRs). The... 

    Deformation of outer representations of galois group II

    , Article Iranian Journal of Mathematical Sciences and Informatics ; Volume 6, Issue 2 , 2011 , Pages 33-41 ; 17354463 (ISSN) Rastegar, A ; Sharif University of Technology
    2011
    Abstract
    This paper is devoted to deformation theory of "anabelian" representations of the absolute Galois group landing in outer automorphism group of the algebraic fundamental group of a hyperbolic smooth curve defined over a number-field. In the first part of this paper, we obtained several universal deformations for Lie-algebra versions of the above representation using the Schlessinger criteria for functors on Artin local rings. In the second part, we use a version of Schlessinger criteria for functors on the Artinian category of nilpotent Lie algebras which is formulated by Pridham, and explore arithmetic applications  

    Deformation of outer representations of Galois group

    , Article Iranian Journal of Mathematical Sciences and Informatics ; Volume 6, Issue 1 , 2011 , Pages 35-52 ; 17354463 (ISSN) Rastegar, A ; Sharif University of Technology
    2011
    Abstract
    To a hyperbolic smooth curve defined over a number-field one naturally associates "ananabelian" representation of the absolute Galois group of the base field landing in outer automorphism group of the algebraic fundamental group. In this paper, we introduce several deformation problems for Lie-algebra versions of the above representation and show that, this way we get a richer structure than those coming from deformations of "abelian" Galois representations induced by the Tate module of associated Jacobian variety. We develop an arithmetic deformation theory of graded Lie algebras with finite dimensional graded components to serve our purpose  

    Arithmetic Teichmuller theory

    , Article Iranian Journal of Mathematical Sciences and Informatics ; Volume 14, Issue 2 , 2019 , Pages 157-171 ; 17354463 (ISSN) Rastegar, A ; Sharif University of Technology
    Iranian Academic Center for Education, Culture and Research  2019
    Abstract
    By Grothendieck’s anabelian conjectures, Galois representations landing in outer automorphism group of the algebraic fundamental group which are associated to hyperbolic smooth curves defined over number-fields encode all the arithmetic information of these curves. The Goal of this paper is to develop an arithmetic Teichmuller theory, by which we mean, introducing arithmetic objects summarizing the arithmetic information coming from all curves of the same topological type defined over number-fields. We also introduce Hecke-Teichmuller Lie algebra which plays the role of Hecke algebra in the anabelian framework. © 2019 Academic Center for Education, Culture and Research TMU  

    Arithmetic teichmuller theory

    , Article Iranian Journal of Mathematical Sciences and Informatics ; Volume 14, Issue 2 , 2019 , Pages 157-171 ; 17354463 (ISSN) Rastegar, A ; Sharif University of Technology
    Iranian Academic Center for Education, Culture and Research  2019
    Abstract
    By Grothendieck’s anabelian conjectures, Galois representations landing in outer automorphism group of the algebraic fundamental group which are associated to hyperbolic smooth curves defined over number-fields encode all the arithmetic information of these curves. The Goal of this paper is to develop an arithmetic Teichmuller theory, by which we mean, introducing arithmetic objects summarizing the arithmetic information coming from all curves of the same topological type defined over number-fields. We also introduce Hecke-Teichmuller Lie algebra which plays the role of Hecke algebra in the anabelian framework. © 2019 Academic Center for Education, Culture and Research TMU  

    Ihara-Type results for siegel modular forms

    , Article Bulletin of the Iranian Mathematical Society ; Volume 46, Issue 3 , 2020 , Pages 693-716 Rastegar, A ; Sharif University of Technology
    Springer  2020
    Abstract
    Let p be a prime not dividing the integer n. By an Ihara result, we mean existence of a cokernel torsion-free injection from a full lattice in the space of p-old modular forms into a full lattice in the space of all modular forms of level pn. In this paper, we will prove an Ihara result in the number field case, for Siegel modular forms. The case of elliptic modular forms is discussed in Ihara (Discrete subgroups of Lie groups and applications to moduli, Oxford University Press, Bombay, 1975). We will use a geometric formulation for the notion of p-old Siegel modular forms (Rastegar in BIMS 43(7):1–23, 2017). Then, we apply an argument by Pappas, and prove the Ihara result using density of... 

    On a theorem of Ihara

    , Article Scientia Iranica ; Volume 12, Issue 1 , 2005 , Pages 1-9 ; 10263098 (ISSN) Rastegar, A ; Sharif University of Technology
    Sharif University of Technology  2005
    Abstract
    Let p be a prime number and let n be a positive integer prime to p. By an Ihara-result, one means the existence of an injection with torsion-free cokernel, from a full lattice, in the space of p-old modular forms, into a full lattice, in the space of all modular forms of level np. In this paper, Ihara-results are proven for genus two Siegel modular forms, Siegel-Jacobi forms and Hilbert modular forms. Ihara did the genus one case of elliptic modular forms [1]. A geometric formulation is proposed for the notion of p-old Siegel modular forms of genus two, using clarifying comments by R. Schmidt [2] and, then, following suggestions in an earlier paper [3] on how to prove Ihara results. The main... 

    Electrospun titania sol-gel-based ceramic composite nanofibers for online micro- solid-phase extraction with high-performance liquid chromatography

    , Article Journal of Separation Science ; Vol. 37, issue. 15 , August , 2014 , pp. 1982-1988 ; ISSN: 16159306 Bagher, H ; Piri-Moghadam, H ; Rastegar, S ; Taheri, N ; Sharif University of Technology
    2014
    Abstract
    Titanium(IV) tetraisopropoxide was employed as a metal oxide sol-gel precursor to prepare ceramic composite nanofibers by the electrospinning system. To facilitate this process and obtain the desired nanofibers with higher aspect ratios and surface area, poly(vinylpyrrolidone) was added to the sol of titania. Four ceramic nanofibers sheets based on titania were prepared while each sheet contained different transition metals such as Fe-Mn, Fe-Ni, Fe-Co, and Fe-Mn-Co-Ni. The scanning electron microscope images showed good homogeneity for all the prepared ceramic composites with a diameter range of 100-250 nm. The sorption efficiency was investigated by a micro-solid-phase extraction setup in... 

    Finite-SNR diversity-multiplexing tradeoff in multi-relay channels

    , Article 2013 Iran Workshop on Communication and Information Theory ; 2013 ; 9781467350235 (ISBN) Haddadpour, F ; Gholami, E ; Rastegar, S. H ; Behroozi, H ; Sharif University of Technology
    2013
    Abstract
    In this paper, we investigate the diversity-multiplexing tradeoff (DMT) for multi-relay channels in finite-SNR regime. In our analysis, we consider the decode and forward (DF) relaying strategy and a line of sight path from source to destination. First, we determine the outage probability in a multi-relay scenario and obtain its exact analytical expressions. Then, the outage probability of a multi-relay channel with relay selection is calculated and provided as a closed-form expression. Based on these results, we determine the DMT in finite-SNR regime. Finally, using simulation results, we show that our analysis has accurate results which coincides with that of obtained from Monte-Carlo... 

    Investigating the impacts of plug-in hybrid electric vehicles on power distribution systems

    , Article IEEE Transactions on Smart Grid ; Volume 4, Issue 3 , 2013 , Pages 1351-1360 ; 19493053 (ISSN) Shafiee, S ; Fotuhi Firuzabad, M ; Rastegar, M
    2013
    Abstract
    Despite the economic and environmental advantages of plug-in hybrid electric vehicles (PHEVs), the increased utilization of PHEVs brings up new concerns for power distribution system decision makers. Impacts of PHEVs on distribution networks, although have been proven to be noticeable, have not been thoroughly investigated for future years. In this paper, a comprehensive model is proposed to study the PHEV impacts on residential distribution systems. In so doing, PHEV fundamental characteristics, i.e., PHEV battery capacity, PHEV state of charge (SOC), and PHEV energy consumption in daily trips, are accurately modeled. As some of these effective characteristics depend on vehicle owner's... 

    MDL-CW: A multimodal deep learning framework with cross weights

    , Article 2016 IEEE Conference on Computer Vision and Pattern Recognition, 26 June 2016 through 1 July 2016 ; Volume 2016-January , 2016 , Pages 2601-2609 ; 10636919 (ISSN) ; 9781467388511 (ISBN) Rastegar, S ; Soleymani Baghshah, M ; Rabiee, H. R ; Shojaee, S. M ; Sharif University of Technology
    IEEE Computer Society  2016
    Abstract
    Deep learning has received much attention as of the most powerful approaches for multimodal representation learning in recent years. An ideal model for multimodal data can reason about missing modalities using the available ones, and usually provides more information when multiple modalities are being considered. All the previous deep models contain separate modality-specific networks and find a shared representation on top of those networks. Therefore, they only consider high level interactions between modalities to find a joint representation for them. In this paper, we propose a multimodal deep learning framework (MDLCW) that exploits the cross weights between representation of... 

    About Space Time

    , M.Sc. Thesis Sharif University of Technology Naderi, Mojtaba (Author) ; Rastegar, Arash (Supervisor)
    Abstract
    Einstein's general theory of relativity is an admirable successful and unifier geometrical modeling among concepts of space, time and gravity. This theory along with special theory of relativity made a massive change in our physical view and this, especially in its historical context, has deep and interesting consequences in man's philosophical viewpoint which can be studied. Some parts of this thesis relates to these consequences. Some of these interesting consequences may be hidden by computional or mathematical viewpoint and often these equations do not contain enough intuition. in one part, we provide a formulizatin of Einstein's equaion that is intuitional which can be translated in... 

    Tropical Algebraic Geometry

    , M.Sc. Thesis Sharif University of Technology Yaghmayi, Keyvan (Author) ; Rastegar, Arash (Supervisor)
    Abstract
    Tropical algebraic geometry is a fairly new branch in geometry which is called so in honor of Brazilian mathematician Imre Simon who was pioneer of this field.The set equipped with the addition and multiplication is a semifield.Algebraic geometry objects like algebraic varieties can be defined over.Polynomials and rational functions are defined over.The functions that they define are piecewise linear and concave functions and the set of points where they are nonlinear is a tropical variety which is a concave polyhedral. Thus, tropical algebraic geometry is a piecewise linear version of algebraic geometry.Another approach to tropical algebraic geometry comes back to the works of Russian... 

    Synthesis and Characterization of Electrospun Ceramic Nanofibers

    , M.Sc. Thesis Sharif University of Technology Rastegar, Soroush (Author) ; Bagheri, Habib (Supervisor)
    Abstract
    Electrospinning is a simple and versatile technique for producing polymeric and ceramic nanofibers. The conventional procedure for fabrication of ceramic nanofibers is a combination of sol-gel techniques and electrospinning. The main challenge is the spin polymer nanofiber in fabricate of fibers with diameter from 1 to 100 nm, while their standard deviation are as low as possible. Uniform beads free polyamidenanofibers with lower diameter were fabricated.A 18% w/w of polyamide in formic acid was chosen and the effect of magnetic field, adding magnetic ionic liquid surfactant, auxiliary electrode on the main fiber were investigated. They termsfiber 1 to fiber 5. The mean diameters of 489,... 

    Deep Learning for Multimodal Data

    , M.Sc. Thesis Sharif University of Technology Rastegar, Sarah (Author) ; Soleymani, Mahdieh (Supervisor)
    Abstract
    Recent advances in data recording has lead to different modalities like text, image, audio and video. Images are annotated and audio accompanies video. Because of distinct modality statistical properties, shallow methods have been unsuccessful in finding a shared representation which maintains the most information about different modalities. Recently, deep networks have been used for extracting high-level representations for multimodal data. In previous methods, for each modality, one modality-specific network was learned. Thus, high-level representations for different modalities were extracted. Since these high-level representations have less difference than raw modalities, a shared... 

    A New Approach Based on Mathematical Modelling and Fuzzy Multi Criteria Decision Making for Supplier Selection in Green Supply Chain

    , M.Sc. Thesis Sharif University of Technology Rastegar, Mohsen (Author) ; Hajji, Alireza (Supervisor)
    Abstract
    Recently, reducing greenhouse gas emissions and the damage to the environment is very important. Due to the increasing environmental awareness of the people on the one hand, and government pressure to reduce damage to the environment on the other hand, has led organizations to pay more attention to this important issue. In addition, these organizations in order to participate in the global competition, should consider green criteria along with other criteria. Hence, the organizations to outsourcing part of their work are looking for Suppliers who along with other criteria also meet the criteria for being green. In this study, a new two-stage approach based on fuzzy... 

    Optimal charge scheduling of PHEV in a multi-carrier energy home

    , Article 2014 14th International Conference on Environment and Electrical Engineering, EEEIC 2014 - Conference Proceedings ; 2014 , p. 199-203 ; ISBN: 9781480000000 Rastegar, M ; Fotuhi-Firuzabad, M ; Sharif University of Technology
    2014
    Abstract
    The presence of different energy carriers as well as the advent of new multi-generation technologies such as combined heat and power (CHP) at homes necessitates designing an integrated model for optimal operation of such multi-carrier energy home. A residential energy hub model including a CHP and a Plug-in hybrid electric vehicle (PHEV) is presented in this paper to show the multi-carrier energy system operation. In addition, this paper proposes an optimization-based formulation for PHEV charging control in the residential energy hub. The payment cost is minimized for the charge scheduling of PHEV through optimization of the residential energy hub operation in response to the...