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    Holographic complexity for R2 and R3 gravities

    , Article Iranian Journal of Physics Research ; Volume 19, Issue 4 , 2020 , Pages 673-681 Naseh, A ; Jafari, G ; Zolfi, H ; Sharif University of Technology
    Isfahan University of Technology  2020
    In this paper, the second and third order corrections of the curvature tensor to the holographic complexity of a temperature state are studied in Hamdis field theory. The dual geometry in this temperature state is the geometry of the Schwarzschild black hole. The calculations made in this paper show that the consideration of these new terms only appears as a constant coefficient in the final result, the rate of growth of complexity over long periods of time. © 2020, Isfahan University of Technology. All rights reserved  

    Distribution of watermark according to image complexity for higher stability

    , Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) ; Volume 3212 , 2004 , Pages 794-801 ; 03029743 (ISSN); 3540232400 (ISBN); 9783540232407 (ISBN) Jamzad, M ; Yaghmaee, F ; Sharif University of Technology
    Springer Verlag  2004
    One of the main objectives of all watermarking algorithms is to provide a secure method for detecting all or part of the watermark pattern in case of usual attacks to a watermarked image. In this paper we introduce a method that is suitable for any spatial domain watermarking algorithms, such that, it can provide a measure for the level of robustness when a given watermark is supposed to be embedded in a known host image. In order to increase the robustness of the watermarked image, for a watermark of n bits, we embed it s times. Doing this, the entire image is divided into 16 equal size blocks. For each block the complexity of the sub-image in that block is measured. The number of... 

    A new and highly effective method for catalytic oxidation of alcohols to the corresponding carbonyl compounds using the tris[(2-oxazolinyl)phenolato] manganese(III)/Oxone®/n-Bu4NBr oxidation system

    , Article Tetrahedron Letters ; Volume 44, Issue 50 , 2003 , Pages 8943-8945 ; 00404039 (ISSN) Bagherzadeh, M ; Sharif University of Technology
    Elsevier Ltd  2003
    Oxone® (2KHSO5·KHSO4·K 2SO4) in the presence of mer-tris[(2-oxazolinyl)phenolato] manganese(III), Mn(phox)3, as catalyst under biphasic reaction conditions (CH2Cl2/H2O) and tetra-n-butylammonium bromide as phase transfer agent efficiently oxidises alcohols to their corresponding aldehydes and ketones at room temperature with very short reaction times (5 min) and good to quantitative yields. © 2003 Elsevier Ltd. All rights reserved  

    A memory efficient algorithm for multi-dimensional wavelet transform based on lifting

    , Article 2003 IEEE International Conference on Accoustics, Speech, and Signal Processing, Hong Kong, 6 April 2003 through 10 April 2003 ; Volume 6 , 2003 , Pages 401-404 ; 15206149 (ISSN) Taghavi, Z ; Kasaei, S ; Sharif University of Technology
    Conventional implementation of multi-dimensional wavelet transform (e.g. 3-D wavelet) requires whether a high amount of "in access" memory or a continual access to slow memory of a processor which makes it infeasible for most applications. In this paper, we proposed a novel algorithm for computation of an n-D discrete wavelet transform (DWT) based on lifting scheme. In addition to benefits of lifting scheme (which causes a major reduction in computational complexity and performs the total computations in time domain), our real-time approach computes the coefficients for all kinds of 1st and 2 nd generation wavelets with short delay and optimized utilization of the slow and fast memories of a... 

    A new efficient PNLMS based algorithm for adaptive line echo cancellation

    , Article 7th International Symposium on Signal Processing and Its Applications, ISSPA 2003, Paris, 1 July 2003 through 4 July 2003 ; Volume 2 , 2003 , Pages 555-558 ; 0780379462 (ISBN); 9780780379466 (ISBN) Maleki, A ; Nayebi, K ; Sharif University of Technology
    IEEE Computer Society  2003
    Echo cancellers with long impulse responses are usually used in networks with long echoes. Since long adaptive filters with sparse target filters usually converge very slowly, adaptation algorithms with fast convergence rate are needed. PNLMS [2] is one of the algorithms that is designed for fast convergence on sparse impulse responses. But there are some disadvantages to this algorithm. The computational complexity of this algorithm is prohibitive, especially for long echo tails. Another disadvantage is that its convergence rate slows down significantly after the adaptation of large taps. In this paper we propose new algorithms to solve both these problems. In another part of this paper, we... 

    Tris[(2-oxazolinyl)phenolato]manganese(III) as catalyst for mild and efficient oxidation of sulfides to sulfones with Oxone®

    , Article Journal of Chemical Research - Part S ; Issue 12 , 2003 , Pages 765-767 ; 03082342 (ISSN) Bagherzadeh, M ; Sharif University of Technology
    Scientific Reviews Ltd  2003
    Tris[(2-oxazolinyl)phenolato]manganese(III), Mn(phox)3, catalysed oxidation of dialkyl, diaryl, dibenzyl, and alkyl aryl sulfides to the corresponding sulfones is carried out by Oxone® in biphasic conditions (CH2Cl2/H2O), in the presence of tetra n-butylammonium bromide as phase transfer agent at room temperature in very short reaction times (5 min.) with quantitative yields  

    Novel unsymmetrical tetradentate Schiff base complexes of cobalt (II) and palladium (II) with N2O2 donor sets

    , Article Journal of Chemical Research - Part S ; Issue 6 , 2001 , Pages 224-226 ; 03082342 (ISSN) Boghaei, D. M ; Mohebi, S ; Sharif University of Technology
    The novel unsymmetrical tetradentate Schiff base complexes of Co(II) and Pd(II) with the general formula M(SaI.Phen.Acac.) and M(Sal.Phen. Naph.), have been synthesised by template and non-template method  

    Proposing a Method for Evaluating Cognitive Complexity of Modeling Languages

    , M.Sc. Thesis Sharif University of Technology Davari Zanjani, Iman (Author) ; Mirian Hosseinabadi, Hassan (Supervisor)
    Modeling languages are well-known mechanisms for describing the underlying structures in software and many other contexts. In order to use an information technology product to solve a specific problem, such as a modeling language, not only there is a need to cognize the problem and search for its solution, but also it’s necessary to have a correct perception of context and details of modeling language in first place. One of the setbacks that users encounter in perceiving the sense of diagrams and their details is cognitive complexity. Although lots of modeling languages are defined and introduced up to now, but there are no suitable yardsticks to evaluate the cognitive complexity of users... 

    Synthesis of New Dithiocarbamate Complexes Based on Diamines Prepard from Cinnamaldehyde

    , M.Sc. Thesis Sharif University of Technology Soleymani Movahed, Farzaneh (Author) ; Saeedi, Mohammad Saeed (Supervisor) ; Ziyaei Halimehjani, Azim (Co-Advisor)
    Dithiocarbamate is one of the most useful components in the science of chemistry. They are used not only in agriculture as fungicides but also in photochemistry in order to determine and analyse NO in biological processes as well as in polymerization routes. Dithiocarbamates which are known as bidentate ligands with high yield are applied in many fields such as producing chemical drugs, functioning as intermediates in organic synthesis, protecting groups in peptide synthesis as well as highly chelating ligands. Regarding the high practically of dithiocarbamates and by focusing on their synthesis process, we have applied them as bidentate ligands. Cinnamaldehyde was condensed in ethanol with... 

    Using Deep Learning to Control of Complex Systems

    , M.Sc. Thesis Sharif University of Technology Aminorroaya, Saba (Author) ; Rahimi Tabar, Mohammad Reza (Supervisor)
    A complex system consists of a large number of subsystems that interact with each other and with the environment. These systems have collective behaviors that may are desired and undesired. Learning, intelligence and epilepsy are examples of desirable and undesirable collective behaviors. Control of these systems arises when they are out of the desired state or one wants to avoid approaching the system to its undesired state. For control of complex systems, we need external functions that apply to specific subsystems. These functions can be obtained from the numerical solution of Hamilton-Jacobi-Bellman equation. The Hamilton-Jacobi-Bellman equation is nonlinear and must be solved at very... 

    Paths of technological capability building in complex capital goods: The case of hydro electricity generation systems in Iran

    , Article Technological Forecasting and Social Change ; 2016 ; 00401625 (ISSN) Kiamehr, M ; Sharif University of Technology
    Elsevier Inc  2016
    This paper investigates the accumulation of technological capability in latecomer suppliers of complex capital goods by exploring the issue in an Iranian supplier of large hydro electricity generation systems. The findings suggest that, contrary to the conventional paths of catch-up in Asian and Latin American mass-producing electronics firms, and instead of starting from early stages of product lifecycle, the technological capabilities in this case were acquired through a non-linear movement within the stages of designing and installing complex capital goods in projects: starting from the middle stage (engineering and realisation of complex goods in projects), moving to the last stage... 

    Synthesis, structure characterization and study of a new molybdenum schiff base complex as an epoxidation catalyst with very high turnover numbers

    , Article Inorganic Chemistry Communications ; Volume 84 , 2017 , Pages 63-67 ; 13877003 (ISSN) Bagherzadeh, M ; Ataie, S ; Mahmoudi, H ; Janczak, J ; Sharif University of Technology
    The reaction between [MoO2(acac)2] and an ONO type Schiff-base ligand (L = 4-bromo-2-((2-hydroxy-5-methylphenylimino)methyl)phenol) resulted a new oligomer molybdenum complex ([MoO2(L)]n). The oligomer complex was characterized by elemental analysis, FT-IR, 1H and 13C NMR spectroscopies. A suitable single crystal of the complex was grown in DMSO and characterized by X-ray single crystal diffraction as monomer stabilized by one DMSO molecule, [MoO2L(DMSO)]. The [MoO2(L)]n complex was used as a catalyst in epoxidation of olefins. Besides the high activity and selectivity, very high turnover numbers were a remarkable advantage of the catalytic system. © 2017  

    Synthesis, characterization, and comparison of two new copper(II)complexes containing Schiff-base and diazo ligands as new catalysts in CuAAC reaction

    , Article Inorganica Chimica Acta ; Volume 492 , 2019 , Pages 213-220 ; 00201693 (ISSN) Bagherzadeh, M ; Mahmoudi, H ; Ataie, S ; Hafezi-Kahnamouei, M ; Shahrokhian, S ; Bellachioma, G ; Vaccaro, L ; Sharif University of Technology
    Elsevier S.A  2019
    Two copper(II)complexes were synthesized through the reaction of Cu(OAc)2·H2O with a Schiff-base ligand (1-(((3,4-dichlorophenyl)imino)methyl)naphthalen-2-ol)and a diazo ligand (1-((3,4-dichlorophenyl)diazenyl)naphthalen-2-ol)in methanol. The complexes and ligands were characterized employing elemental analysis and electronic spectra. In addition, the ligands were fully characterized by using several 1D and 2D NMR techniques. Single crystal X-ray crystallography was also used for the characterization of some of these materials. Due to finding out the effect of Schiff-base and diazo ligands nature on the catalytic activity, the complexes were catalytically compared in one-pot azide-alkyne... 

    Synthesis and characterization of water-soluble zinc(II) Schiff-base complexes derived from amino acids and 3-formyl-4-hydroxybenzyl- triphenylphosphonium chloride

    , Article Journal of Coordination Chemistry ; Volume 61, Issue 12 , 2008 , Pages 1917-1926 ; 00958972 (ISSN) Boghaei, D. M ; Askarizadeh, E ; Sharif University of Technology
    Tridentate Schiff-base ligands derived from condensation of 3-formyl-4-hydroxybenzyl-triphenylphosphonium chloride with glycine, L-alanine, L-valine, L-leucine and L-phenylalanine in the presence of Zn(OAc)2·2H2O form five new water-soluble Zn(II) complexes, which were characterized by elemental analyses, IR, electronic absorption and 1H, 13C NMR spectroscopies. In the IR spectra of the complexes, the difference between the asymmetric and the symmetric carboxylate stretching frequencies is larger than ∼210 cm-1, which implies that the carboxylate groups are monodentate. UV-Vis electronic absorption studies show that Zn(II) functions as a trap for the Schiff-base intermediate. Schiff-base... 

    Synthesis and characterization of novel water-soluble zinc(II) Schiff-base complexes derived from amino acids and salicylaldehyde-5-sulfonates

    , Article Journal of Coordination Chemistry ; Volume 60, Issue 3 , 2007 , Pages 339-346 ; 00958972 (ISSN) Boghaei, D. M ; Gharagozlou, M ; Sharif University of Technology
    New water-soluble zinc(II) Schiff-base complexes derived from amino acids (glycine, L-phenylalanine, and L-valine) and salicylaldehyde-5-sulfonates (sodium salicylaldehyde-5-sulfonate and sodium 3-methoxy-salicylaldehyde-5- sulfonate) have been synthesized. The complexes were characterized by elemental analysis, IR, electronic, 1H NMR, and 13C NMR spectra. In the IR spectra of the complexes, the large difference between the asymmetric νas(COO) and symmetric νs(COO) carboxylate stretch, Δν(νas(COO)-νs(COO)) of 199-247 cm-1, indicates monodentate coordination of the carboxylate group. Spectral data showed that in these complexes the ligand is a tridentate ONO moiety, coordinating to the metal... 

    An improved attack on A5/1

    , Article 2011 8th International ISC Conference on Information Security and Cryptology, ISCISC 2011, 14 September 2011 through 15 September 2011, Mashhad ; 2011 , Pages 41-44 ; 9781467300773 (ISBN) Amin Ghafari, V ; Mohajeri, J ; Sharif University of Technology
    A5/1 is a stream cipher used in GSM to provide over-the-air communication privacy. Biham and Dunkelman proposed an attack on A5/1 with time complexity of 2∧(39.91) and data complexity of 2∧(21.1) known bits and memory complexity of 32 GB. In this paper, we propose an improvement on their attack. Our improvement is identification and elimination of useless states from the precomputed table. Furthermore, we propose another way for use of table in online phase of attack that causes decreasing in the time complexity to 2∧(37.89) and memory complexity decreases to half  

    Five- and six-coordinated silver(I) complexes formed by a metallomacrocyclic ligand with a “Au2N2” donor group: observation of pendulum and linear motions and dual phosphorescence

    , Article Inorganic Chemistry ; Volume 59, Issue 8 , 31 March , 2020 , Pages 5702-5712 Nayeri, S ; Jamali, S ; Jamjah, A ; Shakirova, J. R ; Tunik, S. P ; Gurzhiy, V ; Samouei, H ; Shahsavari, H. R ; Sharif University of Technology
    American Chemical Society  2020
    The six-coordinated silver(I) complex [Au2Ag(μ-(PPh2)2py)2(OTf)2](OTf), 4 (py = pyridine, OTf = CF3SO3), and the five-coordinated silver(I) complex [Au2Ag(acetone)(μ-(PPh2)2py)2](PF6)3, 6, were prepared by the reaction of the precursor complexes 1(OTf)2 and 1(PF6)2, in which 1 = [Au2(μ-(PPh2)2py)2]2+, with 1 equiv of Ag(OTf) in dichloromethane and excess of Ag(PF6) in a mixture of dichloromethane/acetone, respectively. Also, the five-coordinated silver(I) complex [Au2Ag(μ-(PPh2)2py)2(py)(OTf)](OTf)2, 5, was obtained by the reaction of 4 with pyridine. The clusters 4-6 were characterized using multinuclear NMR spectroscopy and elemental microanalysis. The single-crystal X-ray diffraction... 

    Synthesis, characterization, electrochemical studies and catecholase-like activity of a series of mononuclear Cu(II), homodinuclear Cu(II)Cu(II) and heterodinuclear Cu(II)Ni(II) complexes of a phenol-based compartmental ligand

    , Article Journal of Molecular Catalysis A: Chemical ; Volume 241, Issue 1-2 , 2005 , Pages 1-7 ; 13811169 (ISSN) Boghaei, D. M ; Behzad, M ; Bezaatpour, A ; Sharif University of Technology
    A series of previously reported mononuclear Cu(II) and homodinuclear Cu(II)Cu(II) complexes, as well as, novel mononuclear Cu(II), homodinuclear Cu(II)Cu(II), and heterodinuclear Cu(II)Ni(II) complexes of a phenol-based dinucleating ligand with two different N(amine)2O2 and N(imine)2O2 coordination sites, were synthesized and characterized by elemental analyses, infrared and electronic absorption spectroscopies and conductivity measurements. The electrochemical behavior and catecholase-like activity of the complexes were also studied using cyclic voltammetry and UV-vis spectrophotometry, respectively. Our results show that the dinuclear complexes are more effective catalysts in the oxidation... 

    Synthesis and Characterization of Heterobinuclear Cyclometalated Complexes Containing Small Bite Angle Bridging Ligand

    , M.Sc. Thesis Sharif University of Technology Ghazfar, Reza (Author) ; Jamali, Sirous (Supervisor)
    The heteronuclear complexes [MePt(bhq)(μ-dppy)Au(PPh3)]PF6, 2, [MePt(bhq)(dppy)Tl]PF6, 3 and [Me2Pt2(bhq)2(dppy)2Tl]PF6, 4 in which bhq=benzo{h}quinoline and dppy=2-diphenylphosphinopyridine, were prepared by reaction of the mononuclear complex [MePt(bhq)(dppy)] 1 with 1 equivAuCl(PPh3), 1equiv TlPF6 and 1/2 equiv TlPF6 respectively. All the complexes were fully characterized using multinuclear NMR spectroscopy and ESI-MS spectrometry. In addition molecular structures of complexes 2 and 3 in solid state have been determined by X-ray crystallography that shown strong dative bonds between platinum and gold or thallium atoms. As shown by ESI-MS spectrometry, the Pt-Au bond in complex 2... 

    Low-data complexity biclique cryptanalysis of block ciphers with application to piccolo and HIGHT

    , Article IEEE Transactions on Information Forensics and Security ; Vol. 9, Issue. 10 , 2005 , Pages 1641-1652 Ahmadi, S ; Ahmadian, Z ; Mohajeri, J ; Aref, M. R ; Sharif University of Technology
    In this paper, we present a framework for biclique cryptanalysis of block ciphers which extremely requires a low amount of data. To that end, we enjoy a new representation of biclique attack based on a new concept of cutset that describes our attack more clearly. Then, an algorithm for choosing two differential characteristics is presented to simultaneously minimize the data complexity and control the computational complexity. Then, we characterize those block ciphers that are vulnerable to this technique and among them, we apply this attack on lightweight block ciphers Piccolo-80, Piccolo-128, and HIGHT. The data complexity of these attacks is only 16-plaintext-ciphertext pairs, which is...