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    Optimal Calibration of the Seismic Design Base Shear of Steel Structures by Minimizing the Lifecycle Cost and Its Uncertainty

    , M.Sc. Thesis Sharif University of Technology Bagheri, Atiyeh (Author) ; Mahsuli, Mojtaba (Supervisor) ; Hosseini Varzandeh, Saeed (Co-Supervisor)
    Abstract
    This research focuses on determining the optimal base shear coefficient for the design of conventional steel buildings based on the minimization of lifecycle cost (LCC) and associated uncertainties throughout the service life of the building. Current seismic design codes are calibrated based on engineering judgment, acceptable societal risk, or past earthquake experiences. However, technical literature has shown that such calibration does not lead to a design that optimally balances construction costs and seismic damage. As a solution, lifecycle cost-based calibration has been proposed. In this study, the optimal range of the base shear coefficient is determined by minimizing the expected... 

    Probabilistic framework for robust optimal code calibration through minimization of the lifecycle cost and its uncertainty

    , Article Bulletin of Earthquake Engineering ; Volume 22, Issue 4 , 2024 , Pages 1719-1747 ; 1570761X (ISSN) Hosseini Varzandeh, S. S ; Mahsuli, M ; Sharif University of Technology
    Harvard University  2024
    Abstract
    Seismic design codes strive to strike a balance between construction cost and seismic losses. To this end, current codes calibrate design provisions to the accepted practice. However, the literature demonstrates that calibration by minimizing the expected lifecycle cost (LCC) is the rational approach to determine the optimal design. This paper proposes a probabilistic framework for calibrating design provisions that minimizes not only the expected LCC, but also its measure of uncertainty. The framework is then applied to determine the optimal design base shear coefficient of building structures. The proposed methodology is built upon the premise that the expected LCC varies negligibly with... 

    Seismic Risk Assessment of Conventional Reinforced Concrete Building Structures Using Endurance Time Method

    , M.Sc. Thesis Sharif University of Technology Hosseini Varzandeh, Saeed (Author) ; Esmaeil Purestekanchi, Homayoon (Supervisor)
    Abstract
    This study aims to assess and compare the seismic performance of moment frame and dual reinforced concrete systems at different ductilities and seismicity levels. Seismic performance of the systems is defined as their efficiency in providing safety and reducing the life-cycle as well as the total cost of the buildings. For this purpose, 30 archetypes were designed in accordance with common Iranian codes, and their response at different seismic intensities was obtained by Endurance Time method. Afterward, the consequences of earthquakes were estimated according to FEMA-P58 guidelines, and the total cost of the buildings was determined. All of these archetypes had residential occupancy but... 

    Seismic performance of buildings during the magnitude 7.3 Kermanshah, Iran earthquake

    , Article Journal of Building Engineering ; Volume 91 , 2024 ; 23527102 (ISSN) Hosseini Varzandeh, S. S ; Mahsuli, M ; Kashani, H ; Dolatshahi, K. M ; Hamidia, M ; Sharif University of Technology
    2024
    Abstract
    In this paper, the findings and data of a large-scale reconnaissance mission following the November 12, 2017, M7.3 Kermanshah earthquake near the Iran-Iraq border are presented. The earthquake affected multiple cities in both countries and led to widespread damage and notable casualties and fatalities. The highest peak ground acceleration was recorded in Sarpol-e Zahab at 0.7g. As part of two trips, the data on nearly 1200 buildings in eight cities were collected by devising a sampling scheme to maximize the coverage of the survey, which was then employed to compile regional damage statistics. The spatial distribution of damage is presented for the entire region as well as various cities and... 

    Automation of Vision Measurement Machine to Develop Parts Profile Dimensional Measurement Algorithm based on Machine Vision and Image Processing Technique Algorithms

    , M.Sc. Thesis Sharif University of Technology Hosseini, Arian (Author) ; Khodaygan, Saeed (Supervisor)
    Abstract
    Automated dimensional inspection is commonly expensive because of the requirement for high-precision measurement devices. To perform a precision measurement, the technician must be highly skilled and fully understands the operation of the equipment. Moreover, automation of the mentioned process to reduce dimensional measurement time is a complicated task due to restrictions of precise equipment such as CMM. With the expansion of the use of cameras in the industry, the measurement method with the help of machine vision systems is one of the cost-effective methods that can be achieved with the development of a suitable image processing algorithm to achieve acceptable accuracy compared to... 

    Analysis of Walking Strategy using Exoskeleton

    , M.Sc. Thesis Sharif University of Technology Hosseini, Milad (Author) ; Behzadipour, Saeed (Supervisor)
    Abstract
    Walking with lower-limb exoskeletons, particularly in individuals with limited motor abilities, presents numerous challenges. One of the most critical limitations is the absence of an active ankle joint in many commercial exoskeletons. This deficiency prevents users from naturally transferring their center of mass over the peak of potential energy, as the ankle normally plays a crucial role in generating forward propulsion and transferring energy between steps. The lack of this energy source forces users to adopt compensatory strategies that have not yet been thoroughly identified or analyzed. In this study, aiming to precisely analyze the gait mechanism in the presence of an exoskeleton... 

    Preparation and Application of Carbon Nanotube-polypyrrole Modified Electrode in Electrochemical Determination of Mesalazine

    , M.Sc. Thesis Sharif University of Technology Hosseini Yazdeli, Pouya (Author) ; Shahrokhian, Saeed (Supervisor)
    Abstract
    In this work, the glassy carbon electrode (GCE) was modified with a thin layer of multi-walled carbon nanotubes (MWCNTs) and consequently, electrochemically deposited poly-pyrrole. The electrochemical behavior of mesalazine was studied on the surface of the modified electrode by applying linear sweep voltammetry (LSV). The electro-polymerization process and the electrochemical response toward mesalazine were investigated in the presence of different aromatic anion dopants including, benzenesulfonic acid (BSA), 1,3-benzenedisulfonic acid (1,3-BDSA), 1,5-naphthalenedisulfonic acid (1,5-NDSA) and new coccine (NC). By using 1,5-NDSA as dopant, a significant increase (∼418 times) was observed in... 

    Risk-based Framework for Optimal Calibration of Building Seismic Design Provisions through Minimization of Lifecycle Cost

    , Ph.D. Dissertation Sharif University of Technology Saeed Hosseini Varzandeh (Author) ; Mahsuli, Mojtaba (Supervisor)
    Abstract
    This dissertation proposes a probabilistic framework for optimal calibration of design provisions based on the minimization of lifecycle cost (LCC) and its uncertainty. Subsequently, this framework is utilized to determine the optimal robust design base shear coefficient of building structures, and propose a methodology for codifying it while preserving the current structure of the base shear equation. In the first part of the proposed methodology, various structures are designed with different seismic base shears. Then, at each site, their LCC comprising the construction costs and seismic losses is calculated. Various types of seismic loss considered in this study include the direct... 

    Introduction of Methods and Instructions for Life Extension and Recovery of Turbocharger Turbine wheel 900

    , M.Sc. Thesis Sharif University of Technology Mohammad Hosseini, Javad (Author) ; Adibnazari, Saeed (Supervisor)
    Abstract
    Turbochargers are industrial devices that widely are used in aviation, marine and automotive industry. Manufacturing cost and technology of their components vary according to their application fields. One of the most important components of these devices is turbine wheel, which needs to be solid, strong and have a high resistance in critical extraordinary conditions. In these days, it can be seen that superalloys are used remarkably in manufacturing of turbine wheels. When this part of turbine is damaged due to some different reasons, turbine wheel must be quit of circle Process according to repair instructions. In these conditions either turbine must be repaired or replaced by a new one;... 

    Multiscale Finite Volume Method for Simulation of Compressible Multiphase Flow in Porous Media

    , M.Sc. Thesis Sharif University of Technology Hosseini, Sajad (Author) ; Jamshidi, Saeed (Supervisor) ; Masihi, Mohsen (Supervisor)
    Abstract
    Today, due to a massive increase in accuracy of reservoir characterization models, multiphase flow simulation on real permeability fields faces a serious challenge. Using multiscale methods in reservoir flow simulation of a heterogeneous environment has led to huge speed-up of the simulation. In multiscale methods, instead of replacing a heterogeneous medium by an equivalent homogeneous medium, used in upscaling, the problem is solved on the original resolution. In this thesis, multiscale finite volume method (MSFV) has been used to simulate flow and saturation behavior of a black oil model. Unlike the original multiscale finite volume methods that were unable to solve compressible fluid... 

    Dynamic Modeling of Mud Loss in Iranian Fields Using Novel Multiphysics Methods

    , M.Sc. Thesis Sharif University of Technology Hosseini, Ala (Author) ; Shad, Saeed (Supervisor) ; Zivar, Davood (Co-Supervisor)
    Abstract
    The mud loss and its impact on the formation play a vital role in the productivity of the formation and the near wellbore area. Despite the importance of the use of mud during the drilling process, one cannot overlook the issues that may be caused by losing mud into the formation. In addition to the formation damage caused by mud loss, the cost associated with such phenomenon and drilling operational issues and challenges has motivated the industry to look into different avenues to resolve the mud loss issue or reduce its impact. Evaluating the impact of such a phenomenon on these issues requires accurate modeling. In this study different models have been developed to evaluate the impact of... 

    Quantification of optimal target reliability for seismic design: Methodology and application to steel buildings

    , Article Soil Dynamics and Earthquake Engineering ; Volume 170 , 2023 ; 02677261 (ISSN) Habibi, K ; Hosseini Varzandeh, S. S ; Mahsuli, M ; Sharif University of Technology
    Elsevier Ltd  2023
    Abstract
    The reliability levels against which seismic standards are calibrated are currently quantified based on accepted practice, which may not lead to optimal designs that minimize the lifecycle cost. Deviation from optimal design is even more pronounced in countries whose regulations are adopted from the few leading codes. A major challenge in the quantification of optimal target reliability for the countries with such adopted codes is the lack of risk models that are suited for the local construction industry and design practices. This paper presents a holistic risk-based framework to quantify the optimal target reliability for seismic design through the notion of minimum lifecycle cost. To... 

    Experimental and Simulation Study of Barite Settlement Phenomenon under Static and Dynamic Condition

    , M.Sc. Thesis Sharif University of Technology Movahhedi, Hamed (Author) ; Shad, Saeed (Supervisor) ; Hosseini Mokhtari, Zahra (Co-Advisor)
    Abstract
    In petroleum related drilling, Barite particles settling and Barite sag as major problems in drilling wells can potentially impose significant operational issues. In this study, a computational fluid dynamics (CFD) and experimental investigation of Barite settlement in annular space were conducted in both static and dynamic conditions. The Euler-Euler approach was used to model the multiphase flow of solid Barite particles and drilling fluid. In this approach, the momentum lost between phases has been taken into account by means of particle-particle and particle-fluid exchange coefficients. The governing equations were numerically solved using finite volume method by CFD software package... 

    Modeling of Nano-Aerosol Deposition in Human Lung in Successive Respiratory Cycles

    , M.Sc. Thesis Sharif University of Technology Nemati, Hossein (Author) ; Saeedi, Mohammad Saeed (Supervisor) ; Hosseini, Vahid (Co-Advisor)
    Abstract
    Particulates are a group of air pollutants. They can enter the respiratory system by breathing and cause adverse effects on its performance. Also, inhaled drugs, recently have found many applications in the field of drug delivery. Prediction of particle deposition in the lungs during breathing, can provide useful information on the effects of deposited particles on the respiratory system. When a person is exposed to breathable particulates, after a while with completion of a few respiratory cycles, particle deposition rate, reaches a certain amount at the quasi-steady state. A lot of researchers have investigated particle deposition in the lung, but all of them have studied a single... 

    Numerical Modeling of Fluid Flow and Proppant Transport in Hydraulic Fracture Using Extended Finite Element Method

    , Ph.D. Dissertation Sharif University of Technology Hosseini, Navid (Author) ; Khoei, Amir Reza (Supervisor) ; Shad, Saeed (Co-Supervisor)
    Abstract
    Transport phenomena in porous media play important role in many areas of subsurface hydrology, geo-physics, environment, energy and petroleum. The work in the field of numerical modeling of fractured porous media is yet an open area of research. The classic finite element method (FEM) has some limitations in modeling of discontinuities like fracture. FEM mesh should conform with the geometry of the fracture. Presence of fracture imposes discontinuity in pressure field of fluid phases and displacement field of solid phase (rock). To represent the fractures, the extended finite element method (X-FEM) can be used in which the standard finite element approximation of the field variables is... 

    Influence of Rejuvenation Treatment on Microstructure and Creep Properties of Damaged IN738LC Superalloy

    , Ph.D. Dissertation Sharif University of Technology Hosseini, Shahabeddin (Author) ; Nategh, Saeed (Supervisor) ; Ekrami, Ali Akbar (Supervisor)
    Abstract
    The goal of the present study is to investigate the effect of rejuvenation treatment on microstructure and creep properties of damaged IN738LC superalloy. Virgin alloy was damaged by interrupted creep tests at 926°C and 170 MPa for 100, 200 and 250 hours. The results obtained showed that damaging the virgin alloy by interrupted creep tests resulted in microstructural deterioration (consisting of coarsening of ' precipitates, formation of continuous films of ' on grain boundary regions and formation of transition zone around MC carbides) and, consequently, degradation of creep properties. Rejuvenation treatment was carried out with the purpose of healing the damaged alloy and restoration of... 

    Multi-Agent Machine Learning in Self-Organizing Systems

    , M.Sc. Thesis Sharif University of Technology Hejazi Hosseini, Ehsan (Author) ; Nobakhti, Amin (Supervisor) ; Bagheri Shouraki, Saeed (Supervisor)
    Abstract
    This paper develops a novel insight and procedure that includes a variety of algorithms for finding the best solution in a structured multi-agent system with internal communications and a global purpose. In other words, it finds the optimal communication structure among agents and the optimal policy in this structure. First, a unique reinforcement learning algorithm is proposed to find the optimal policy of each agent in a fixed structure with non-linear function approximation like artificial neural networks (ANN) and eligibility traces. Secondly, a mechanism is presented to perform self-organization based on the information of the learned policy. Finally, an algorithm that can discover an... 

    A new hybrid model using step-wise weight assessment ratio analysis (SWARA) technique and adaptive neuro-fuzzy inference system (ANFIS) for regional landslide hazard assessment in Iran

    , Article Catena ; Volume 135 , 2015 , Pages 122-148 ; 03418162 (ISSN) Dehnavi, A ; Aghdam, I. N ; Pradhan, B ; Morshed Varzandeh, M. H ; Sharif University of Technology
    Elsevier  2015
    Abstract
    In recent years, Iran has experienced many landslides due to high tectonic activity, and a variety of geological and climatic conditions. This paper proposes a novel hybrid model based on step-wise weight assessment ratio analysis (SWARA) method and adaptive neuro-fuzzy inference system (ANFIS) to evaluate landslide susceptible areas using geographical information system (GIS). At first, based on an inventory map, landslide locations were randomly divided into two parts, 70% of which were used for generating the landslide hazard map and 30% of which were used for the validation of the model. Then, twelve landslide predisposing factors, such as lithology, slope angle, slope aspect, plan... 

    Seismic hazard assessment for Iran in terms of macroseismic intensity

    , Article Bulletin of Earthquake Engineering ; Volume 22, Issue 10 , 2024 , Pages 4823-4842 ; 1570761X (ISSN) Shabani, E ; Albarello, D ; Mahsuli, M ; Eghbali, N ; Varzandeh, S. H ; Farnetani, F ; Sharif University of Technology
    2024
    Abstract
    We present the results of probabilistic seismic hazard assessment for Iran based on a statistical procedure specifically developed to manage macroseismic intensity data. This method takes into careful consideration the specific features of such data, which are characterized as ordinal, discrete, and confined within a finite interval, ensuring a logically coherent approach throughout the analysis. The results of our assessment are then compared with hazard maps generated using a standard approach, putting in evidence significant differences both on a national scale and relative to individual cities. This comparative analysis will be useful in identifying areas of utmost concern, where further... 

    Performance of three-level spectrally encoded spreadtime CDMA in the presence of multiple interferences [electronic resource]

    , Article IET Communications ; July 2011, Volume 5, Issue 10, P. 1328-1335 Mashhadi, S. (Saeed) ; Mashhadi, Saeed ; Salehi, J. A ; Sharif University of Technology
    Abstract
    In this study the authors present an in-depth study, analysis and discussion on maximum likelihood (ML)-based receiver for a typical spectrally encoded spread-time CDMA in the presence of multiple narrowband interference (NBI) signals in an additive white Gaussian noise channel. Furthermore, the authors demonstrate that by combining useful properties of ML-based receiver and three-level codes, that is, codes with values of -1, 0, +1, the authors can introduce a new strategy in which superior performance with respect to previous receiver structure based on two-level codes, that is, codes with values of -1, +1, can be attained. With the help of an example, the authors drive, first, the...