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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) ; 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...
Knee Joint Torque Estimation using EMG Signals for Sharif Exoskeleton Control Applications
, M.Sc. Thesis Sharif University of Technology ; 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...
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) ; 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...
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) ; 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...
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) ; 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 ; 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 ; 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 ; 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...
Prediction of CO2 equilibrium moisture content using least squares support vector machines algorithm
, Article Petroleum and Coal ; Volume 58, Issue 1 , 2016 , Pages 27-46 ; 13377027 (ISSN) ; Abdi, J ; Bahadori, M ; Lee, M ; Bahadori, A ; Sharif University of Technology
Slovnaft VURUP a.s
2016
Abstract
The burning of fossil fuels such as gasoline, coal, oil, natural gas in combustion reactions results in the production of carbon dioxide. The phase behavior of the carbon dioxide + water system is complex topic. Unlike methane, CO2 exhibits a minimum in the water content. These minima cannot be predicted by existing methods accurately. In this communication, two mathematical-based procedures have been proposed for accurate computation of CO2 water content for tempe-ratures between 273.15 and 348.15 K and the pressure range between 0.5 and 21 MPa. The first is based on least squares support vector machine (LSSVM) algorithm and the second applies multilayer perceptron (MLP) artificial neural...
Increasing the antioxidant activity of green tea polyphenols in the presence of iron for the reduction of graphene oxide
, Article Carbon ; Volume 50, Issue 8 , 2012 , Pages 3015-3025 ; 00086223 (ISSN) ; Kalaee, M ; Alavi, Z. S ; Ghiasi, S. M. A ; Esfandiar, A ; Sharif University of Technology
2012
Abstract
An easy method for green and low-temperature (40 °C) reduction of graphene oxide (GO) by increasing the antioxidant activity of green tea polyphenols (GTPs) in the presence of iron was developed. The reduction level (obtained by X-ray photoelectron spectroscopy) and electrical conductivity (obtained by current-voltage measurement) of the GO sheets reduced by GTPs in the presence of iron were comparable to those of hydrazine-reduced GO and much better than those of the GO reduced by only GTPs (in the absence of iron) at reduction temperatures of 40-80 °C. Raman spectroscopy indicated that application of GTPs in the presence of iron, in contrast to hydrazine, resulted in better recovering of...
Inclusion of Pediococcus acidilactici as probiotic candidate in diets for beluga (Huso huso) modifies biochemical parameters and improves immune functions
, Article Fish Physiology and Biochemistry ; Volume 44, Issue 4 , 2018 , Pages 1099-1107 ; 09201742 (ISSN) ; Binaii, M ; Naghavi, A ; Khoshbavar Rostami, H ; Nori, H ; Amerizadeh, A ; Sharif University of Technology
Springer Netherlands
2018
Abstract
Administration of probiotic candidates in fish has generally been shown as a useful strategy to improve growth performance, survival, digestive enzyme activity, and gut microbiota. Unfortunately, the sero-immunological responses of different fish to different probiotic candidates are poorly understood. The present study assessed the effect of Pediococcus acidilactici as a probiotic on the biochemical and immunological parameters of beluga. Fish (248.32 ± 10.21 g) were fed a control diet (without P. acidilactici(and three different doses of P. acidilactici-supplemented diets (107, 108, and 109 CFUg−1 diets) for 8 weeks. On week 8, blood and serum were sampled. Dose-dependent increase of...
LOKOIRAN - A novel robot for rehabilitation of spinal cord injury and stroke patients
, Article International Conference on Robotics and Mechatronics, ICRoM 2013, Tehran ; 2013 , Pages 218-223 ; 9781467358118 (ISBN) ; Hadian, M. R ; Mousavi, M ; Rassaf, A ; Ghiasi, F ; Sharif University of Technology
2013
Abstract
This paper will focus on the design and development of a new gait training robotic device (LOKOIRAN) for patients with balance and locomotion disorders. The process of rehabilitation in this system is based on partial weight bearing system and programmable foot-plate training. The system consisted of several subsystems following: Driving and transmission system, back supporting system, leg exoskeleton, body weight support system and control system. A virtual reality environment was also designed and integrated to the system in order to motivate patients during rehabilitation protocol. The experimental tests on healthy subjects were performed to evaluate the performances of mechanical and...
Effects of stabilizers on sustainability, activity and decolorization performance of Manganese Peroxidase enzyme produced by Phanerochaete chrysosporium
, Article Journal of Environmental Chemical Engineering ; Volume 8, Issue 6 , 2020 ; Zolfaghari, P ; Golizadeh, M ; Karimi, A ; Lau, A ; Ghiasi, B ; Ansari, Z ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Manganese Peroxidase (MnP), is one of the most promising lignin depolymerization enzymes, which has been widely used for degradation purposes. Nevertheless, MnP tends to lose activity rapidly during its maintenance phase and degradation process, especially in the inevitable presence of hydrogen peroxide. This study aimed to improve MnP efficiency produced by Phanerochaete chrysosporium, via enhancing its sustainability. In this context, the effects of MnO2, Fe3O4, PEG, Veratryl Alcohol (VA), and DMSO as stabilizing agents on MnP activity were explored both in vivo and in vitro. During in vivo experiments, heterogeneous Fe3O4 was found to be the desirable choice to enhance MnP production,...
Time-scalable mapping for circuit-switched GALS chip multiprocessor platforms
, Article IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems ; Vol. 33, issue. 5 , May , 2014 , p. 752-762 ; Hashemi, M ; Mahini, A ; Baas, B. M ; Ghiasi, S ; Sharif University of Technology
2014
Abstract
We study the problem of mapping concurrent tasks of an application to cores of a chip multiprocessor that utilize circuit-switched interconnect and global asynchronous local synchronous (GALS) clocking domains. We develop a configurable algorithm that naturally handles a number of practical requirements, such as architectural features of the target platform, core failures, and hardware accelerators, and in addition, is scalable to a large number of tasks and cores. Experiments with several real life applications show that our algorithm outperforms manual mapping, integer linear programming-based mapping after ten days of solver run time, and a recent packet-switched network on chip-based...
A novel stability and kinematics-driven trunk biomechanical model to estimate muscle and spinal forces
, Article Medical Engineering and Physics ; Vol. 36, issue. 10 , 2014 , p. 1296-1304 ; Arjmand, N ; Shirazi-Adl, A ; Farahmand, F ; Ghiasi, M. S ; Sharif University of Technology
2014
Abstract
An anatomically detailed eighteen-rotational-degrees-of-freedom model of the human spine using optimization constrained to equilibrium and stability requirements is developed and used to simulate several symmetric tasks in upright and flexed standing postures. Predictions of this stability and kinematics-driven (S. +. KD) model for trunk muscle forces and spine compressive/shear loads are compared to those of our existing kinematics-driven (KD) model where both translational and rotational degrees-of-freedom are included but redundancy is resolved using equilibrium conditions alone. Unlike the KD model, the S. +. KD model predicted abdominal co-contractions that, in agreement with...
Graphene oxide strongly inhibits amyloid beta fibrillation
, Article Nanoscale ; Volume 4, Issue 23 , 2012 , Pages 7322-7325 ; 20403364 (ISSN) ; Akhavan, O ; Ghavami, M ; Rezaee, F ; Ghiasi, S. M. A ; Sharif University of Technology
2012
Abstract
Since amyloid beta fibrillation (AβF) plays an important role in the development of neurodegenerative diseases, we investigated the effect of graphene oxide (GO) and their protein-coated surfaces on the kinetics of Aβ fibrillation in the aqueous solution. We showed that GO and their protein-covered surfaces delay the AβF process via adsorption of amyloid monomers. Also, the large available surface of GO sheets can delay the AβF process by adsorption of amyloid monomers. The inhibitory effect of the GO sheet was increased when we increase the concentration from 10% (in vitro; stimulated media) to 100% (in vivo; stimulated media). Conclusion: our results revealed that GO and their surface...
Doubly fed induction generators to enhance inter-area damping based on a Robust controller: H2/ H∞ Control
, Article SN Applied Sciences ; Volume 3, Issue 1 , 2021 ; 25233971 (ISSN) ; Ranjbar, A. M ; Dehghani, M ; Ghasemi Garpachi, M ; Ghiasi, M ; Sharif University of Technology
Springer Nature
2021
Abstract
In this study, an auxiliary damping controller based on a robust controller considering the active and reactive power control loops for a doubly-fed induction generator for wind farms is proposed. The presented controller is able to improve the inter-area oscillation damping. In addition, the proposed controller applies only one accessible local signal as the input; however, it can improve the inter-area oscillation damping and, consequently the system stability for the various working conditions and uncertainties. The oscillatory modes of the system are appointed using the linear analysis. Then, the controller’s parameters are determined using the robust control approaches (H∞/ H2) with the...
Dynamic NMR studies of N-benzoyl pyrrolidine and N-benzoyl piperidine derivatives
, Article Journal of Molecular Structure ; Volume 886, Issue 1-3 , August , 2008 , Pages 24-31 ; 00222860 (ISSN) ; Ziyaei Halimjani, A ; Ghiasi, M ; Fattahi, M ; Saidi, M. R ; Sharif University of Technology
2008
Abstract
Variable-temperature 1H and 13C NMR spectroscopy are used to investigate barrier of C-N rotation in series of amides, such as N-benzoyl pyrrolidine, N-(4-chlorobenzoyl) pyrrolidine, N-(4-methoxybenzoyl) pyrrolidine, N-(4-chlorobenzoyl) piperidine, and N-(4-methoxybenzoyl) piperidine. Δ G298≠ of 65.2, 60.6, 58.8, 60.1, and 57.1 kJ mol-1are found for the above compounds, respectively. Theoretical studies were done for these compounds and the results showed good agreement with the experimental results. Theoretical and experimental results showed that substituted methoxy group on the para position of benzene ring decreases the rotational barrier. Increasing steric effect and therefore...
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) ; 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) ; 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)...