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    Chemometrics-assisted isotope ratio fingerprinting based on gas chromatography/combustion/isotope ratio mass spectrometry for saffron authentication

    , Article Journal of Chromatography A ; Volume 1657 , 2021 ; 00219673 (ISSN) Ghiasi, S ; Parastar, H ; Sharif University of Technology
    Elsevier B.V  2021
    Abstract
    In the present contribution, the capability of isotopic ratio mass spectrometry (IRMS) for saffron authentication and detection of four common plant-derived adulterants (marigold flower, safflower, rubia, and saffron style) was investigated. For this purpose, 62 authentic saffron samples were analyzed by elemental analyzer-IRMS (EA-IRMS) and gas chromatography-combustion-IRMS (GC-C-IRMS). In this regard, EA-IRMS and GC-C-IRMS isotope fingerprints of carbon-13 and nitrogen-15 isotopes of saffron components were provided and then analyzed by chemometric methods. Principal component analysis (PCA) showed two different behaviors regarding two main regions. Then, a representative saffron sample... 

    An Integrated Land-Use and Transportation Model for the Evaluation of Urban Development Decisions

    , M.Sc. Thesis Sharif University of Technology Ghiasi, Amir (Author) ; Poorzahedy, Hossain (Supervisor)
    Abstract
    Land-use and transportation are inter-related, such that land-use may be used to control transportation. This study aims to design a suitable combination of the residential and service land-use on one side, and the transportation system on the other side. The model presented in this study has two external and internal levels, and its objective is to minimize the cost of residence, receiving goods and services, and transportation. The performance of any combination of spatial allocation of population and employment, as well as transportation, is evaluated by the internal level of the model which determines the interaction between population, employment, and transportation. This is done by a... 

    Cramér’s Model for Random Primes

    , M.Sc. Thesis Sharif University of Technology Ghiasi, Mohammad (Author) ; Alishahi, Kasra (Supervisor)
    Abstract
    With Cramer’s model we have a probability measure on the power set of N. This probability measure is concentrated on the set that its elements are that subsets of N which number of their elements up to a certain natural number is asymptotically equal with the number of primes up to the same number. Let Pc be a sample obtained from this probability measure and consider 8n 2 N, an counts the number of ways that ncan be represented as a multiplication of some elements of Pc, such that changing the arrangement of factors in a representation does not introduce a new one. In this thesis, we prove that limn!1 a1++an n almost surely exists and is positive  

    Study & Analysis of Delays Causes of Gas Projects in Tehran Gas Company & presenting Optimized Solutions by Applying Project Management Principles

    , M.Sc. Thesis Sharif University of Technology Ghiasi, Elahe (Author) ; Mostafavi, Mostafa (Supervisor)
    Abstract
    To deliver gas in time to different consumers like as industrial, commercial and domestic users is one of the most important parts in gas industry. So it is very important to utilize these projects in the specified time. There are huge harms for client, contractors and consumers when there is a delay in project utilization. To identify effective parameters on delays to remove them in future is an essential factor. In this research, all delay causes for TPGC (Tehran Province Gas Company) projects are analyzed and some solutions to remove these delays are presented. 10 hypotheses in relation of gas delivery have been assumed as delay causes. Then some questions have been discussed in relation... 

    Dynamic stereochemistry of rutin (vitamin P) in solution: Theoretical approaches and experimental validation

    , Article Carbohydrate Research ; Volume 345, Issue 12 , 2010 , Pages 1760-1766 ; 00086215 (ISSN) Ghiasi, M ; Taheri, S ; Tafazzoli, M ; Sharif University of Technology
    2010
    Abstract
    The 3D structure of vitamin P, an important bioflavonoid, has been studied in solution by 2D NMR spectroscopy and QM calculations. Rutin, vitamin P, was extracted from Salvia macrosiphon and identified by 1H, 13C, 1H-1H COSY, HMQC, and HMBC spectroscopy. In parallel, density functional theory (DFT) using B3LYP functional and split-valance 6-311G basis set has been used to optimize the structures and conformers of rutin. Also experimental and theoretical methods have been used to correlate the dependencies of 1J, 2J, and 3J involving 1H and 13C on the C5″-C6″ (ω), C6″-O6″ (θ), and C1‴-O6″ () torsion angles in the glycosidic moiety. New Karplus equations are proposed to assist in the... 

    Chrysin/β-cyclodextrin supramolecular system: a quantum mechanical investigation

    , Article Journal of the Iranian Chemical Society ; Volume 15, Issue 10 , 2018 , Pages 2401-2410 ; 1735207X (ISSN) Ghiasi, M ; Gerayeli, N ; Tafazzoli, M ; Sharif University of Technology
    2018
    Abstract
    Chrysin is a bioflavonoid which possesses a wide range of important biological activities. In present study, we used a quantum mechanical approach to shed light on the antioxidant ability and antioxidant mechanism of chrysin to scavenge hydroxyl radical (˙OH) in solution phase. The analysis of the theoretical bond dissociation enthalpy (BDE) values and spin density of the radicals to determine the delocalization possibilities at B3LYP/6-311++G** level clearly shows the importance of the A-ring and the 7-OH group in antioxidant reactivity. In the next step, the inclusion of chrysin with β-CD has been investigated extensively using theoretical methods. Density functional theory (M05-2X)... 

    The Control of an exoskeleton and the reduction of interaction force using human intent detection by EMG signals and torque estimation

    , Article Proceedings of the 6th RSI International Conference on Robotics and Mechatronics, IcRoM 2018, 23 October 2018 through 25 October 2018 ; 2019 , Pages 536-541 ; 9781728101279 (ISBN) Ghiasi Noughaby, A ; Vossoughi, G. R ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Abstract
    Disability and motor disorders are some of the problems that people may face due to some factors such as accident, spinal cord injuries, brain damage, and the presence of a problem in neurological commands due to stroke. One of the proposed methods for solving the problems of these people is the use of exoskeletons to generate movement. The main goal of this paper is the control of Sharif Exoskeleton Robot and the reduction of interaction force between user and robot by using human intent detection. This goal is done by estimating the knee torque of one degree of freedom in a swing phase using Hill model based on the EMG data from the thigh muscles. Accordingly, the calibration algorithm is... 

    Role of axial ligand on the electronic structures of active intermediates in cytochrome P-450, peroxidase and catalase

    , Article Journal of Molecular Structure: THEOCHEM ; Volume 820, Issue 1-3 , 2007 , Pages 18-25 ; 01661280 (ISSN) Ghiasi, M ; Tafazzoli, M ; Safari, N ; Sharif University of Technology
    2007
    Abstract
    DFT method (B3LYP) with 6-31G* basis set was utilized in the computation of a fully optimized structure, net atomic charges and spin densities of the intermediate of cytochrome P-450-oxoiron(IV) porphyrin cation radical, compound I - in the presence of axial ligand such as thiolate (SMe-) imidazole (IM), phenoxide (OPh-), methoxide (OMe-) and chloride (Cl-). The results show doublet states in compound I are about 2-4 kcal/mol more stable than quartet states for all aforementioned ligands, and the doublet state is the ground state in all cases. However, electron donor ability of the ligands are in the order of SMe- > IM > OMe- > OPh- > Cl-. Also the active oxidant intermediate of cytochrome... 

    Knee Joint Torque Estimation using EMG Signals for Sharif Exoskeleton Control Applications

    , M.Sc. Thesis Sharif University of Technology Ghiasi Noughaby, Amir (Author) ; Vossoughi, Gholamreza (Supervisor)
    Abstract
    The human body has more than 600 muscles that cause movement. Disability and motor disorders are some of the problems that people may face due to some factors such as accident, spinal cord injuries, disorders and brain damage, and the presence of a problem in neurological commands due to stroke. One of the proposed methods for solving the problems of people with motor disorder is the use of exoskeletons to generate stimulus. Exoskeletones are electromechanical devices designed to assist human movement, and patients are used to correct their movements using specific motor patterns. Exoskeletones can also be used as an auxiliary device for carrying heavy loads. Many studies have been conducted... 

    Development of Chemometric Methods Combined with Isotope Ratio Mass Spectrometry (IRMS) for Isotope Pattern Recognition and Adulteration Detection in Foods

    , M.Sc. Thesis Sharif University of Technology Ghiasi, Ali (Author) ; Parastar Shahri, Hadi (Supervisor)
    Abstract
    The purpose of this study was to investigate the capability of Isotopic Ratio Mass Spectrometry (IRMS) in the detection of four common natural plant frauds in saffron, namely Marigold flower, Safflower, Rubia and Saffron Style. For this purpose, first natural saffron isotopes were analyzed and used to investigate fingerprints of carbon-13 and nitrogen-15 isotopes by Elemental Analyzer Isotopic Ratio Mass Spectrometry (EA-IRMS) and carbon-13 isotopic ratio of saffron components by Gas Chromatography Isotopic Ratio Mass Spectrometry (GC-C-IRMS). Then, according to the isotopic behavior of the original saffron, they were sampled to form a mixture of saffron that is representative of the... 

    Throughput-memory footprint trade-off in synthesis of streaming software on embedded multiprocessors

    , Article Transactions on Embedded Computing Systems ; Volume 13, Issue 3 , December , 2013 ; 15399087 (ISSN) Hashemi, M ; Foroozannejad, M. H ; Ghiasi, S ; Sharif University of Technology
    2013
    Abstract
    We study the trade-off between throughput and memory footprint of embedded software that is synthesized from acyclic static dataflow (task graph) specifications targeting distributed memory multiprocessors. We identify iteration overlapping as a knob in the synthesis process by which one can trade application throughput for its memory requirement. Given an initial processor assignment and non-overlapped task schedule, we formally present underlying properties of the problem, such as constraints on a valid iteration overlapping, maximum possible throughput, and minimum memory footprint. Moreover, we develop an effective algorithm for generation of a rich set of design points that provide a... 

    Low-Frequency model for hand-calculations in circuit design with TMDC-based transistors

    , Article IEEE Transactions on Electron Devices ; Volume 66, Issue 11 , 2019 , Pages 5011-5018 ; 00189383 (ISSN) Omdeh Ghiasi, H ; Safarian, A ; Pourfath, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Abstract
    This article presents an applicable intuitive current-voltage model for long-channel transistors based on 2-D materials. This model carefully predicts the transistor behavior in the saturation and triode regions, which are important for analog and digital applications. Moreover, the effect of mobility degradation on the characteristics of the transistor is probed. As a case study, the developed model has been applied to a transistor with mono-layer MoS2 as the channel material. The excellent agreement with experimental data verifies the accuracy of the model. Finally, the introduced model has been utilized to design an amplifier, a differential pair, and a low-frequency common source mixer... 

    A new model reference adaptive control structure for uncertain switched systems with unmodeled input dynamics

    , Article Transactions of the Institute of Measurement and Control ; Volume 37, Issue 10 , 2015 , Pages 1171-1180 ; 01423312 (ISSN) Sinafar, B ; Rikhtehgar Ghiasi, A ; Karimi Fazli, A ; Sharif University of Technology
    SAGE Publications Ltd  2015
    Abstract
    In this paper, a new model reference adaptive controller (MRAC) for uncertain switched linear systems is developed. A class of uncertain switched linear systems with parametric mismatched and input matched uncertainties, control input effectiveness and unmodeled dynamics is studied in this paper. The difference in input matrix for different switching modes which means the input channel degradation is investigated through this paper. By using common Lyapunov function method and developing new linear matrix inequality based sufficient conditions, uniform ultimate boundedness of the reference tracking error is guaranteed by switched MRAC and by using a novel nonlinear controller term, the size... 

    Reduction of Graphene Oxide by Polyphenols of Green Tea in the Presence of Oxidation of Transition Metals

    , M.Sc. Thesis Sharif University of Technology Ghiasi Shirazi, Mohammad Amin (Author) ; Akhavan, Omid (Supervisor)
    Abstract
    In this research, we have used green tea polyphenols as green reductants for reduction of graphene oxide. Furthermore, for the first time, the presence of some metals such as iron, tungsten and copper in the efficiency of reduction is investigated. XPS spectra indicate that iron can be considered as one of the best choices for helping polyphenols in the reduction process. Hence, we used AFM, XPS, Raman spectroscopy and I-V diagram to characterize graphene oxide reduced by polyphenols and iron. In recent years, hydrazine has been recognized as one of the standard reducing agents for effective reduction of graphene oxide. In our analysis, it is found that the conductivity of our reduced... 

    The Study of Antioxidant Mechanism of some Flavonoids without and in Presence of Cyclodextrins: Theoretical Point of View

    , Ph.D. Dissertation Sharif University of Technology Gerayeli, Narges (Author) ; Tafazzoli, Mohsen (Supervisor) ; Ghiasi, Mina (Co-Supervisor)
    Abstract
    Antioxidants are compounds with anti-cancer, anti-bacterial, anti-viral, anti-aging and anti-allergic properties. In the present study, a quantum mechanical approach has been used to shed light on the presence effect of glycoside group on the antioxidant ability of chrysin as one of the most important consumable flavonoids and two glycoside derivatives, chrysin-6-C-fucopyranoside and chrysin-3-malonyl-6-C-fucopyranoside which has electron-withdrawing group (EWG) in its C3 of glycoside group. Density functional theory (DFT) using B3LYP and UB3LYP functional and split-valance 6-311++G ** basis set were used to optimize chrysin, its different derivatives, and their radicals. Analysis of... 

    Formless: scalable utilization of embedded manycores in streaming applications

    , Article Proceedings of the ACM SIGPLAN Conference on Languages, Compilers, and Tools for Embedded Systems (LCTES) ; 2012 , Pages 71-78 ; 9781450312127 (ISBN) Hashemi, M ; Foroozannejad, M. H ; Ghiasi, S ; Etzel, C ; Sharif University of Technology
    2012
    Abstract
    Variants of dataflow specification models are widely used to synthesize streaming applications for distributed-memory parallel processors. We argue that current practice of specifying streaming applications using rigid dataflow models, implicitly prohibits a number of platform oriented optimizations and hence limits portability and scalability with respect to number of processors. We motivate Functionally-cOnsistent stRucturally-MalLEabe Streaming Specification, dubbed FORMLESS, which refers to raising the abstraction level beyond fixed-structure dataflow to address its portability and scalability limitations. To demonstrate the potential of the idea, we develop a design space exploration... 

    Implementation-aware model analysis: The case of buffer-throughput tradeoff in streaming applications

    , Article Proceedings of the ACM SIGPLAN Conference on Languages, Compilers, and Tools for Embedded Systems (LCTES), 18 June 2015 through 19 June 2015 ; Volume 2015-June , 2015 , Pages 108-117 ; 9781450332576 (ISBN) Mirzazad Barijough, K ; Hashemi, M ; Khibin, V ; Ghiasi, S ; Sharif University of Technology
    Association for Computing Machinery  2015
    Abstract
    Models of computation abstract away a number of implementation details in favor of well-defined semantics. While this has unquestionable benefits, we argue that analysis of models solely based on operational semantics (implementation oblivious analysis) is unfit to drive implementation design space exploration. Specifically, we study the tradeoff between buffer size and streaming throughput in applications modeled as synchronous data flow (SDF) graphs. We demonstrate the inherent inaccuracy of implementation-oblivious approach, which only considers SDF operational semantic. We propose a rigorous transformation, which equips the state of the art buffer-throughput tradeoff analysis technique... 

    Implementation-aware model analysis: The case of buffer-throughput tradeoff in streaming applications

    , Article ACM SIGPLAN Notices ; Volume 50, Issue 5 , May , 2015 , Pages 103-112 ; 15232867 (ISSN) Barijough, K. M ; Hashemi, M ; Khibin, V ; Ghiasi, S ; Sharif University of Technology
    Association for Computing Machinery  2015
    Abstract
    Models of computation abstract away a number of implementation details in favor of well-defined semantics. While this has unquestionable benefits, we argue that analysis of models solely based on operational semantics (implementationoblivious analysis) is unfit to drive implementation design space exploration. Specifically, we study the tradeoff between buffer size and streaming throughput in applications modeled as synchronous data flow (SDF) graphs. We demonstrate the inherent inaccuracy of implementationoblivious approach, which only considers SDF operational semantic. We propose a rigorous transformation, which equips the state of the art buffer-throughput tradeoff analysis technique... 

    Investigation of trunk muscle activities during lifting using a multi-objective optimization-based model and intelligent optimization algorithms

    , Article Medical and Biological Engineering and Computing ; Volume 54, Issue 2-3 , 2016 , Pages 431-440 ; 01400118 (ISSN) Ghiasi, M. S ; Arjmand, N ; Boroushaki, M ; Farahmand, F ; Sharif University of Technology
    Springer Verlag  2016
    Abstract
    A six-degree-of-freedom musculoskeletal model of the lumbar spine was developed to predict the activity of trunk muscles during light, moderate and heavy lifting tasks in standing posture. The model was formulated into a multi-objective optimization problem, minimizing the sum of the cubed muscle stresses and maximizing the spinal stability index. Two intelligent optimization algorithms, i.e., the vector evaluated particle swarm optimization (VEPSO) and nondominated sorting genetic algorithm (NSGA), were employed to solve the optimization problem. The optimal solution for each task was then found in the way that the corresponding in vivo intradiscal pressure could be reproduced. Results... 

    CNNdroid: GPU-accelerated execution of trained deep convolutional neural networks on android

    , Article 24th ACM Multimedia Conference, MM 2016, 15 October 2016 through 19 October 2016 ; 2016 , Pages 1201-1205 ; 9781450336031 (ISBN) Latifi Oskouei, S. S ; Golestani, H ; Hashemi, M ; Ghiasi, S ; Sharif University of Technology
    Association for Computing Machinery, Inc  2016
    Abstract
    Many mobile applications running on smartphones and wear- able devices would potentially benefit from the accuracy and scalability of deep CNN-based machine learning algorithms. However, performance and energy consumption limitations make the execution of such computationally intensive algorithms on mobile devices prohibitive. We present a GPU- accelerated library, dubbed CNNdroid [1], for execution of trained deep CNNs on Android-based mobile devices. Empirical evaluations show that CNNdroid achieves up to 60X speedup and 130X energy saving on current mobile devices. The CNNdroid open source library is available for download at https://github.com/ENCP/CNNdroid