Studying the Effect of Motor Learning on Muscle Synergies During Balance

, M.Sc. Thesis Sharif University of Technology Karami, Hojat (Author) ; Farahmand, Farzam (Supervisor) ; Baniasad, Mina (Co-Supervisor)

Abstract

Our body makes use of many degrees of freedom in muscle space. As a result, there are many solutions for activating muscles when performing a specific task. “how our central nervous system (CNS) controls abundant degrees of freedom?” has been a popular question for researchers in the field of motor control since Bernstein. The existence of muscle synergies is one of the proposed hypothesis, and there is experimental evidence that they are encoded in our CNS as building blocks. The aim of this study is to study the effect of training on the number, structures, and activation profiles of muscle synergies that are used for maintaining balance. For this purpose, electromyography data from 28...

Green supply chain network design considering inventory-location-routing problem: A fuzzy solution approach

, Article International Journal of Logistics Systems and Management ; Volume 35, Issue 4 , 2020 , Pages 436-452 Gholipour, S ; Ashoftehfard, A ; Mina, H ; Sharif University of Technology

Inderscience Publishers 2020

Abstract

The growing rate of population and technological advancement have led to an increase in natural resource consumption, which has caused irreparable damage to the environment. The implementation of green supply chain management is one of the most effective ways to deal with environmental degradation. Therefore, in this paper, a bi-objective mixed integer linear programming model is developed to design a green supply chain network. In the proposed model, the possibility of customer storage, being faced with shortage, locating of distribution centres, green vehicle routing problem, split delivery, multi-depot vehicle routing problem (VRP), capacitated VRP, and uncertainty in demands will be...

A dynamic decision support system for sustainable supplier selection in circular economy

, Article Sustainable Production and Consumption ; Volume 27 , 2021 , Pages 905-920 ; 23525509 (ISSN) Alavi, B ; Tavana, M ; Mina, H ; Sharif University of Technology

Elsevier B.V 2021

Abstract

Supplier selection is an important and challenging problem in sustainable supply chain management. We propose a dynamic decision support system (DSS) for sustainable supplier selection in circular supply chains. Unlike the linear take-make-waste-dispose production systems, circular supply chains are nonlinear make-waste-recycle production systems with zero-waste vision. The proposed DSS allows users to customize and weight their economic, social, and circular criteria with a fuzzy best-worst method (BWM) and select the most suitable supplier with the fuzzy inference system (FIS). Machine learning is used to maintain and synthesize the criteria scores for the suppliers after each supplier...

A dynamic decision support system for sustainable supplier selection in circular economy

, Article Sustainable Production and Consumption ; Volume 27 , 2021 , Pages 905-920 ; 23525509 (ISSN) Alavi, B ; Tavana, M ; Mina, H ; Sharif University of Technology

Elsevier B.V 2021

Abstract

Supplier selection is an important and challenging problem in sustainable supply chain management. We propose a dynamic decision support system (DSS) for sustainable supplier selection in circular supply chains. Unlike the linear take-make-waste-dispose production systems, circular supply chains are nonlinear make-waste-recycle production systems with zero-waste vision. The proposed DSS allows users to customize and weight their economic, social, and circular criteria with a fuzzy best-worst method (BWM) and select the most suitable supplier with the fuzzy inference system (FIS). Machine learning is used to maintain and synthesize the criteria scores for the suppliers after each supplier...

Synthesis of TiO2 nano powder by the sol-gel method and its use as a photocatalyst

, Article Journal of the Iranian Chemical Society ; Volume 7, Issue SUPPL. 1 , 2010 , Pages S154-S160 ; 1735207X (ISSN) Karami, A ; Sharif University of Technology

2010

Abstract

In this work the titanium dioxide powder was prepared by the optimized and simple Sol-Gel method and then characterized. The gelling pH was set to values of 3 (TiO2-A), 7 (TiO2-N) and 9 (TiO2-B) to observe the effect on the properties of the material. In these three cases nanoparticulated materials were obtained with particle sizes between 10nm and 20nm. The larger surface areas were obtained at pH 3, which is several times larger than the others. Furthermore, with the gelling condition pH 3, it was possible to synthesize pure anatase phase titania. Some preliminary results on the test of the photocatalytic activity of the synthesized materials in the reduction of nitric oxide are presented....

Study on modification of colloidal silica surface with magnesium ions

, Article Journal of Colloid and Interface Science ; 2009 , Pages 379-383 ; 00219797 (ISSN) Karami, A ; Sharif University of Technology

2009

Abstract

The prepared colloidal silica via ion exchange was modified by adding Mg+2 ions in the surface growth process of colloidal silica. The particle size of the modified colloidal silica was decreased by increasing the seed concentration, whereas that of colloidal silica was slightly increased as the seeds concentration exceed 15 wt%. But the trend of changes in surface area was completely reversed. Magnesium ions on surface of the modified colloidal silica were identified by the measurement of energy-dispersive X-ray spectrometry (EDS). After modifying with Mg+2 ions, the iso-electric point (IEP) of colloidal silica in pH ∼ 2 without modification, disappears over the whole pH range. © 2008...

A fuzzy solution approach to supplier selection and order allocation in green supply chain considering the location-routing problem

, Article Scientia Iranica ; Volume 28, Issue 1 E , 2021 , Pages 446-464 ; 10263098 (ISSN) Ebrahimi Qazvini, Z ; Haji, A ; Mina, H ; Sharif University of Technology

Sharif University of Technology 2021

Abstract

In the eld of supply chain, selecting a suitable green supplier could signi cantly help us decrease the cost and risks of the operations and increase the quality of green supply. This paper develops an integrated two-stage approach based on Fuzzy Analytic Hierarchy Process (FAHP) and multi-objective mixed-integer linear programming to select suppliers and allocate order in the green supply chain. In the rst stage, suppliers are evaluated using FAHP method and in the second stage, a multi-product multi-period supply chain is developed considering green location-routing problem, discounting, and time window under uncertainty. Then, a fuzzy solution approach is applied to solve the proposed...

Using Supported Ionic Liquid Membranes (SILMs) for Selective Separation of CO2/CH4

, M.Sc. Thesis Sharif University of Technology M.Barghi, Hamed (Author) ; Rashtchian ,Davood (Supervisor) ; Adibi, Mina (Supervisor)

Abstract

Supported Ionic Liquid Membranes (SILMs) are fabricated by saturating the pores of a porous support with ionic liquids. To assess the performance of SILMS, it is necessary to obtain data about the properties of ionic liquids such as diffusivity, solubility, and etc. To accomplish this task, in this project the permeability and diffusivity of CO2 and CH4 through three immidazolium-based ionic liquids: [bmim][PF6], [hmim][Tf2N], and "1-methyl-3-(3- tri methoxi silil propyl) imidazolium bis (tri fluoro methyl solphonyl)" , in the temperature range between 27-45 ℃ and pressures within 10-50 kPa, are measured. It is shown in data validation section that the results of this study are in good...

Optimization of Production of Biodiesel

, M.Sc. Thesis Sharif University of Technology Azadfar, Mohsen (Author) ; Rashtchian, Davood (Supervisor) ; Adibi, Mina (Supervisor)

Abstract

Reduction in the oil reserves level and the increasing of fossil fuel prices and GHG has led to growing value of attention to biodiesel. Reserves of fossil fuels are running out and should have proper alternative for them. Environmental benign and renewable properties of biodiesel make it consider suitable candidate to replace fossil fuels.
In this study, continuous production of biodiesel and optimization of important and influential parameters have been investigated. The method is concluded of trans esterification of soya oil with methanol as feed in presence of homogeneous catalyst of NaOH. The reactor was simple with high efficiency and low operational and investment cost. The...

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...

Process Design of Ionic Liquid-Based CO2 Capture with Consideration of Economic and Environmental Issues

, M.Sc. Thesis Sharif University of Technology Eidi, Ali (Author) ; Rashtchian, Davood (Supervisor) ; Adibi, Mina (Co-Supervisor)

Abstract

Concerns have increased about global warming caused by CO2 emissions in the atmosphere. At the moment, carbon capture and storage is the best available solution. Among the current technologies for CCS, amine-based chemical absorption appears to be the most common method. Amines show several inherent drawbacks such as high vapor pressure, high energy consumption in regeneration, corrosivity and degradability. So, researchers have developed new solvents with the foresight of being superior to amines. Ionic liquids (ILs) are among the most suitable alternatives. The most prominent feature of ILs is their tunable thermophysical properties. In this work, physical absorption by ILs is chosen as...

A green closed-loop supply chain network: A bi-objective mixed integer linear programming model

, Article International Journal of Operational Research ; Volume 41, Issue 4 , 2021 , Pages 492-513 ; 17457645 (ISSN) Gholipour, S ; Salehian, F ; Lamouchi, H ; Mina, H ; Sharif University of Technology

Inderscience Publishers 2021

Abstract

The increasing level of customer awareness and application of environmental laws by governments, on the one hand, and the increasing number of competitors, on the other hand, has obliged industry owners to include green activities in the design of the supply chain network. Green activities include any type of action that reduces environmental degradation. Hence, this study seeks to develop a bi-objective, mixed integer linear programming (MILP) model for designing a green supply chain network. In the proposed model, the minimisation of costs and detrimental environmental effects are discussed. LP metric method is used to solve the bi-objective model and the proposed model is run by using...

Automated Code Reviewer Recommendation for Pull Requests

, M.Sc. Thesis Sharif University of Technology Moosa Reza, Mina Sadat (Author) ; Heydarnoori, Abbas (Supervisor)

Abstract

Nowadays, by distributed software development growth based on pull-requests, it is possible to review code changes before integrating into the master program by a third-party, informally and tool-based which is called Modern Code Review (MCR). Effectively performing MCR can facilitate the software evolution phase through reducing post-release defects. In MCR, after sending the pull request, the developer invites appropriate reviewers to inspect his code. Due to the high volume of requests and potential reviewers in many projects, selecting the appropriate reviewer is difficult and time consuming. Previously, a variety of recommender systems have been proposed that use methods based on...

Comparing the Besancon Galaxy Model with Hipparcos data

, M.Sc. Thesis Sharif University of Technology Karami, Mansour (Author) ; Rahvar, Sohrab (Supervisor)

Abstract

e H-R diagram for stars within 100 parsecs from the sun were simulated using Padova isorones, Besanc¸on Galaxy disc model and various star formation rates. using Chi-square test the different star formation rates were compared. the results favours an increasing star formation rate

Robust Hover-flight Control Design for a Tail-sitter UAV with Ducted-fan Propulsion

, M.Sc. Thesis Sharif University of Technology Karami, Hossein (Author) ; Saghafi, Faribourz (Supervisor)

Abstract

In this thesis, the theory of robust control is applied to design a controller for hover flight of a tail-sitter unmanned aerial vehicle with 2 ducted-fan propulsion. The control surface deflection (in propeller slipstream) is considered as the input controller of the system. The aircraft dynamical model is developed based on the assumption of no aerodynamic loads on other parts of uav in low speed flight associated with the hovering condition. The controller is primarily designed using both classical and modern control techniques. Then H ∞ and µ synthesis approaches are applied to design the robust controller. The results obtained from different approaches are compared. It is shown that...

Periodic Solutions for a Weakly Dissipated Hybrid System

, M.Sc. Thesis Sharif University of Technology Karami, Hamed (Author) ; Hesaraki, Mahmoud (Supervisor)

Abstract

In this thesis, we consider the motion of a stretched string coupled with a rigid body at one end and we study the existence of periodic solution when a periodic force acts on the body. In this hybrid system, there is a weak dissipation that characterizes. The main difficulty of the study is related to the weak dissipation which does not ensure a uniform decay rate of the energy. In this thesis, firstly, under the condition of 0 1 0 , we prove there exists a periodic solution. Then, we change the conditions on , Indeed, we restrict ourselves to solve the problem. In this case, under the condition of 0 2 0 , we show there is a periodic solution for rational periods. In the last part, by...

Design of a Modern Compact Transmission Line for Electrical Energy Transmission in Long Distances at 400 kV

, M.Sc. Thesis Sharif University of Technology Karami, Marzie (Author) ; Vakilian, Mehdi (Supervisor)

Abstract

With new progresses in technology, a growing need to power energy has emerged. In Iran most of power plants are far from cities and therefore expansion of power network will cause long transmission lines with high capacities which connect power plants to cities. There are three solutions for these kinds of lines: 1) two-circuit transmission lines 2) higher voltages 3) new forms of transmission lines (HVDC and compact). In this thesis some of these suggestions have been analyzed to find the best solution for a 560 Km transmission line in Iran.
Designing transmission lines has a lot of steps which all are related to each other. In this project a comprehensive algorithm has been utilized to...

Positioning, Tracking and Shape Control in Micro-Beams Via Electrostatic Actuators and Incomplete State Feedback

, M.Sc. Thesis Sharif University of Technology Karami, Farzad (Author) ; Salarieh, Hassan (Supervisor)

Abstract

Systems that are electrostatically actuated have found a vast role in MEMS application. This technology is used in optical systems, sensors, micro switches, and deformable mirrors. Raising the use of these systems in fields that needs better performance highlighted the need to accurate study of dynamics and control of electrostatic actuated systems in micro scale. This work is dedicated to design of an estimation and control system for a micro-beam that is actuated by electrostatic. After a comprehensive survey on pervious works that are done on dynamic, applications, fabrication and control of these systems dynamic of the system is fully derived. The environmental factors like fringing...

3D Reconstruction of Football Player Using Multi-view Videos

, M.Sc. Thesis Sharif University of Technology Karami, Mansoureh (Author) ; Kasaei, Shohreh (Supervisor)

Abstract

One major problem in sport match analysis and interpretation is that there are restricted viewpoints of the game. 3D reconstruction allows us to have virtual replay from any viewpoint so that the events such as penalties can be detected easily. For achieving this purpose, we use many cameras with overlapped views that cover almost all parts of the field. After some preprocessing, 3D reconstruction and texture mapping, we can enhance the viewer experience by having arbitrary viewpoint of the match. In this research, we use two different visual hull methods for 3D reconstruction. In the first method, the visual hull of an object is computed efficiently and robustly from image contours. This...

Designing a Multi-Model Sliding Mode Controller for a Magnetic Levitation System

, M.Sc. Thesis Sharif University of Technology Karami, Sasan (Author) ; Haeri, Mohammad (Supervisor)

Abstract

In this project a complete simulator for a two-winding, 25cm air gap Maglev system by considering the pratical constaritns, position and velocity observer and the current sensor dynamics was derived. In order to control the ball in any desired position a twisting sliding mode controller was designed as the basic controller in the rest of project. The designed controller can not transfer the ball in far trajectory. In first step we modify that to reach a better performance by changing the value of current, passing through the coils in steady state. In the second step, the far trajectories are divided to a finite number of sub-trajectory such that the ball can pass these sub-trajectory by...