Source Apportionment of Air Particulate Matter (PM2.5)in Tehran Using CMB Model

, M.Sc. Thesis Sharif University of Technology Roufigar Haghighat, Navid (Author) ; Erhami, Mohammad (Supervisor)

Abstract

In recent years, one of the most important air pollution in Tehran in terms of creating unhealthy air quality is particulate matter and especially PM2.5. Particulate matter in Tehran is released from various sources. Identification of components and estimating the contribution of each emission sources, helps governers to find air pollution control strategies. To find out major components of PM2.5 in Tehran, a one year sampling to collect PM2.5 was conducted from February 2014 through February 2015 in AQM station at Sharif University of Technology located west of Tehran. 24-hour integrated samples collected on a 1-in-6 day schedule on both Teflon and quartz filters. TOT analysis was done for...

Seasonal trends in the composition and sources of PM2.5 and carbonaceous aerosol in Tehran, Iran

, Article Environmental Pollution ; Volume 239 , 2018 , Pages 69-81 ; 02697491 (ISSN) Arhami, M ; Zare Shahne, M ; Hosseini, V ; Roufigar Haghighat, N ; Lai, A. M ; Schauer, J. J ; Sharif University of Technology

Elsevier Ltd 2018

Abstract

Currently PM2.5 is a major air pollution concern in Tehran, Iran due to frequent high levels and possible adverse impacts. In this study, which is the first of its kind to take place in Tehran, composition and sources of PM2.5 and carbonaceous aerosol were determined, and their seasonal trends were studied. In this regard, fine PM samples were collected every six days at a residential station for one year and the chemical constituents including organic marker species, metals, and ions were analyzed by chemical analysis. The source apportionment was performed using organic molecular marker-based CMB receptor modeling. Carbonaceous compounds were the major contributors to fine particulate mass...

CO2/N2 Mixed Gas Separation in Glycerol Liquid Membrane Containing Sodium Carbonate Carriers

, M.Sc. Thesis Sharif University of Technology Haghighat, Parsa (Author) ; Bastani, Darush (Supervisor)

Abstract

In this research, initially the Glycerol liquid membrane with dissolved sodium carbonate carriers, which is supported by CA porous filter, was prepared. The effects of Na2CO3 concentration and pressure difference on gas permeability were investigated. Permeability of CO2 and N2 were measured at pressure difference of 0.7, 1.6, 2.1 and 2.8 bar with carbonate sodium concentration of 0, 1 and 2 mol/lit. Permeability of CO2 was found to be higher than N2. Increasing the pressure difference resulted in an increase in the N2 permeability coefficient while decreased the CO2 permeability coefficient. Increasing the concentration of sodium carbonate increased the CO2 permeability drastically but...

Influence of Shear Wall Positioning in Design of Concrete Frames

, M.Sc. Thesis Sharif University of Technology Haghighat, Reza (Author) ; Maleki, Shervin (Supervisor)

Abstract

Numerous research is available in the literature regarding shear walls. These have considered parameters like wall cross-section, Reinforcement configuration, boundary elements, etc. In addition, seismic and wind loading behavior has been discussed. Currently, the software ETABS is used extensively in automatic design of shear walls, The programs design bases are investigated in this thesis in ragards to flexural, shear and boundary elements of shear walls under seismic loading. The attachment of wall elements to frame (column) elements is of particular interest in this study

Fraud Detection in Financial Transactions

, M.Sc. Thesis Sharif University of Technology Haghighat, Mohammad (Author) ; Beigy, Hamid (Supervisor)

Abstract

With development of electronic payment infrastructures and increase of payment transactions in result, abusing these infrastructures and fraudulent efforts has been increased. Problem of “Fraud Detection in Financial Transactions” is finding these illegal/abnormal transactions while many other legitimate transactions exist. Goal of this thesis is providing a method for fraud detection in financial transactions using representation learning. Many approaches are used for solving fraud detection including classic data mining algorithms and deep learning based methods, which are compared in this thesis. We also covered diverse feature engineering and representation learning ideas for improving...

Range-Doppler Map Generation in the Presence of Sparse Clutter for Multistatic Radar

, M.Sc. Thesis Sharif University of Technology Haghighat, Soheil (Author) ; Karbasi, Mohammad (Supervisor)

Abstract

Multistatic radar has several advantages over monostatic radar (such as better detection), which are due to the use of different viewing angles and the difference in their clutter characteristics. Clutter in many applications (such as marine applications) has the property of being sparse in certain dictionaries. Therefore, the investigation of sparse clutter (such as sea clutter) is of particular importance. It is worth noting that the detection of targets in the vicinity of the sea faces difficulties due to the dynamics of the sea, which causes the Doppler spectrum to change with time and change in space. Considering the fact that the sea clutter is sparse clutter, one of the powerful...

Physics-informed neural network simulation of multiphase poroelasticity using stress-split sequential training

, Article Computer Methods in Applied Mechanics and Engineering ; Volume 397 , 2022 ; 00457825 (ISSN) Haghighat, E ; Amini, D ; Juanes, R ; Sharif University of Technology

Elsevier B.V 2022

Abstract

Physics-informed neural networks (PINNs) have received significant attention as a unified framework for forward, inverse, and surrogate modeling of problems governed by partial differential equations (PDEs). Training PINNs for forward problems, however, pose significant challenges, mainly because of the complex non-convex and multi-objective loss function. In this work, we present a PINN approach to solving the equations of coupled flow and deformation in porous media for both single-phase and multiphase flow. To this end, we construct the solution space using multi-layer neural networks. Due to the dynamics of the problem, we find that incorporating multiple differential relations into the...

Decomposition of Poverty in Iran with Reference to Household’s Socioeconomic Characteristics, Using Integrated Macro and Micro Data

, M.Sc. Thesis Sharif University of Technology Poursadeghi Haghighat, Soheil (Author) ; Neili, Farhad (Supervisor)

Abstract

This research uses the new approach of Son (2003) for the decomposition of poverty in Iran into three separate components of growth, inequality and population effects during 2001 to 2007 and meanwhile uses the integration of microeconomic and macroeconomic data together to increase the accuracy of the results. The main question of this research is to determine the orientation of development strategies for alleviation of poverty in Iran, which could be either growth-oriented or inequality-oriented ones. The resultes suggest that the former has always been pro-poor in Iran and has had the most dominant effect. Therefore, in order to decrease the poverty in Iran in the future, there should be...

Formal Analysis of Security Properties of Homomorphic-Cryptography-Based E-voting Protocols using µCRL

, M.Sc. Thesis Sharif University of Technology Haghighat, Mohammad Hashem (Author) ; Jalili, Rasool (Supervisor)

Abstract

With fast improvements of technology in advances in electronic voting systems, has been very effective in substantially reducing the disadvantages of traditional elections and thus enhancing the legitimacy of those being elective. These systems, to be effective,
ought to be designed based on several security factors such as eligibility, correctness, voters' privacy, verifiability and receipt-freeness. One of the most important issues in this concept is ensuring the satisfaction of these properties. Using an incomplete and vulnerable system may cause negative consequences. Therefore, it is necessary to evaluate the system before implementation. Using formal methods for verification of...

Design and Comparison of Memristor Implementation for Different Machine Learning Algorithms

, M.Sc. Thesis Sharif University of Technology Haghighat, Bahar (Author) ; Bagheri Shouraki, Saeed (Supervisor)

Abstract

The first physical realization of the missing fourth fundamental element of electrical circuits, namely memristor, in 2008 by HP labs triggered an immense amount of research on the capabilities of this element in implementing artificial neurons and artificial brain. In this project we will propose several reinforcement learning-based algorithms that are implemented on a specific memristor-based structure, the memristor crossbar structure. Hence we provide a learning paradigm that resembles the human learning paradigm not only because of the the algorithmic core, which is based on learning from sparse and delayed rewards and penalties, but also because of the hardware over which the...

Seismic Performance of Self-centering Concentrically Steel Braced Structures

, M.Sc. Thesis Sharif University of Technology Haghighat, Ali (Author) ; Kazemi, Mohammad Taghi (Supervisor)

Abstract

The purpose of this thesis is assessment of seismic performance of self-centering concentric braced frames (SC-CBF). In this structures, the column under tension can uplift from the foundation at a specified level of lateral loading and by using some methods such as post-tensioning (PT) bars or tendons, the structure is able to self-center after severe Earthquakes. In this systems, PT bars and energy dissipation elements resist column uplift. The effect of energy dissipation ratio and initial stress in PT bars was investigated in design and performance of four four-story analytical models. Nonlinear static and dynamic analyses were conducted to compare some parameters in these four models...

Modeling Saturated Porous Media Using Extended Finite Element Method

, M.Sc. Thesis Sharif University of Technology Haghighat, Ehsan (Author) ; Khoei, Amir Reza (Supervisor)

Abstract

Soil structures have important roles in civil engineering applications. The most important types of these structures are soil dams and foundations which their damages may cause huge loss. Thus, appropriate analysis of these structures under possible loading conditions is unavoidable. The real behavior of this media can be achieved from the solution of its coupled governing differential equations. In order to solve this set of equations in practical applications, appropriate numerical solutions should be used. The finite element method can be called as one of the most important numerical solutions of differential equations which have been used in analyzing different types of engineering...

Redesign and Reconstruction of a Smart Cane for Blind People to Detect Empty Seats and Social Navigation in Indoor Environments

, M.Sc. Thesis Sharif University of Technology Haghighat Joo, Mahdi (Author) ; Taheri, Alireza (Supervisor)

Abstract

Visual impairments worldwide, especially among blind and visually impaired individuals, pose numerous challenges in mobility and personal independence. This research aims to design and develop a smart cane based on advanced computer vision technologies and deep learning algorithms, capable of real-time obstacle and environmental target detection, while guiding the user along safe and optimal paths that respect social etiquette. The proposed system utilizes an RGB-D OAK-D Lite camera, an IMU sensor, and a Raspberry Pi 5 microcontroller. Obstacle and object detection is implemented based on the advanced YOLOv8 architecture, and dynamic path planning is realized using the D* Lite algorithm. To...

Lumbopelvic Rhythm during Forward and Backward Sagittal Trunk Rotations; in vivo Measurements Using Inertial Sensors

, M.Sc. Thesis Sharif University of Technology Tafazzol, Alireza (Author) ; Arjmand, Navid (Supervisor)

Abstract

Direct in vivo measurements of spinal loads and muscle forces are invasive. Investigators have thus used musculoskeletal biomechanical models that require kinematic data including trunk and pelvis angular movements as their inputs. . Novel devices measure anglular movements using both inertial sensors (such as gyroscopes and accelerometers) and miniature magnetometers. Relative low cost, portability, and accuracy are among specific characteristics of inertial tracking devices. The main objective of the present study was set to measure spinal kinematics including the lumbopelvic rhythm as the ratio of total lumbar rotation over pelvic rotation during trunk sagittal movement which is essential...

Evaluation of 1991 NIOSH Lifting Equation in Controlling the Biomechanical Loads of the Human Spine

, M.Sc. Thesis Sharif University of Technology Lesani, Ali (Author) ; Arjmand, Navid (Supervisor)

Abstract

The 1991 NIOSH Lifting Equation (NLE) is widely used to assess risk of injury to the spine by providing estimates of the recommended weight limit (RWL) in hands. The present study uses two biomechanical models of the spine to verify whether the RWL generates L5-S1 loads within the limits (e.g., 3400 N for compression recommended by NIOSH and 1000 N for shear recommended in some studies).Severallifting activities are simulated here to evaluate the RWL by the NLE and the L5-S1 loads by the models. In lifting activities involving moderate to large forward trunk flexion, the estimated RWL generates L5-S1 spine loads exceeding the recommended limits. The NIOSH vertical multiplier is the likely...

Sagittal Range of Motion of the Thoracic Spine Using Inertial Tracking Device and Effect of Measurement Errors on Model Predictions

, M.Sc. Thesis Sharif University of Technology Hajibozorgi, Mahdieh (Author) ; Arjmand, Navid (Supervisor)

Abstract

Range of motion (ROM) of the thoracic spine has implications in patient discrimination for diagnostic purposes and in biomechanical models for predictions of spinal loads. Few previous studies have reported quite different thoracic ROMs. Total (T1-T12), lower (T5-T12) and upper (T1-T5) thoracic, lumbar (T12-S1), pelvis, and entire trunk (T1) ROMs were measured using an inertial tracking device as asymptomatic subjects flexed forward from their neutral upright position to full forward flexion. Correlations between body height and the ROMs were conducted. Effect of measurement errors of the trunk flexion (T1) on the model-predicted spinal loads was investigated. Mean of peak voluntary total...

A Detailed Finite Element Model of the Lumbar Spine under Muscle Forces

, M.Sc. Thesis Sharif University of Technology Asadi, Hamed (Author) ; Arjmand, Navid (Supervisor)

Abstract

Etiological studies proves the fact that Low Back Pain (LBP) is one of the most expensive and prevalent desease all over the world. This fact illustrates the reqiurment of the special effort in ordet to reducing the pain due to this problem. Finite element modeling of human spine is one the suitable methods to simulate the behavior of human spine in different loading conditions. These conditions could be different daily occupational tasks. There is two general viewpoint toward finite element modeling of human spine. The fisrt method focuses on the detailed geometry and mechanical properties of spine, while the other complexities such as detailed muscle forces are overlooked. The latter...

A Hyrid EMG-optimization Based Model of the Lumbar Spine to Estimate Muscle Forces in Different Tasks

, M.Sc. Thesis Sharif University of Technology Mohammadi, Yousef (Author) ; Arjmand, Navid (Supervisor)

Abstract

Low back pains (LBP) are prevalent and costly. One of the important factors causing LBP is excessive axial compression and shear forces that are applied on the intervertebral discs during different activities. Due to lack of direct in vivo measurement methods for estimating these loads, musculoskeletal biomechanical models have been emerged as indispensable tools under various activities. Different biomechanical models have been suggested to estimate muscle forces and spinal loads base on optimization, EMG and hybrid (EMG assisted optimization, EMGAO) methods. Although there have been a number of studies on the differences between various optimization and EMG-based methods, there has been no...

Effect of Iatrogenic Muscle Injuries on Spine Biomechanics During Posterior Lumbar Surgeries Using a Biomechanical Model for Design of Rehabilitation Exercises

, M.Sc. Thesis Sharif University of Technology Jamshidnezhad, Saman (Author) ; Arjmand, Navid (Supervisor)

Abstract

Posterior lumbar surgery is often associated with extensive injuries to back muscles. In this thesis, the effect of such iatrogenic injuries in some patients was examined. For this purpose, the CSA of back muscles in 6 patients were measured using MR scan. To examine any natural change in CSAs of healthy people or instrument errors, same measurement were carried out on 10 healthy volunteers. In addition, a detailed anatomical model of an intact human spine was developed. With the aim of experimental studies and intact model, the post-operative model of patients was also developed. These two models were used to quantizing the change in activity of back muscles during some symmetric, normal...

3D Measurements of the Thoracic and Lumbar Spine Range of Motions Using Inertial Sensors

, M.Sc. Thesis Sharif University of Technology Narimany, Mohammad (Author) ; Arjmand, Navid (Supervisor)

Abstract

Musculoskeletal abnormalities affect joints and change their range of motion (RoM). Correcting these abnormalities thoroughly depends on the information related to the normal spine movement. Therefore, spine motion analysis can be used as an important tool to distinguish between healthy and patient individuals as well as to determine the intensity of such diseases. Additionally, existing biomechanical models need kinematics data in order to analyze spinal forces. The present study hence aims to measure 3D range of motion of thoracic and lumbar spine using inertial sensors. Their small size, portability, low weight, and relatively low cost make inertial sensors as indispensable tools in...