Investigation of Dynamic Response of Shallow Foundations on Layered Soils to Horizontal Harmonic Loading by Physical Model Tests

, M.Sc. Thesis Sharif University of Technology Ashoori, Taha (Author) ; Jafarzadeh, Fardin (Supervisor)

Abstract

Increasing requirements of industries and research institutes to analytical results of interaction soil-foundation related systems, reveals the importance of the dynamic impedance functions than ever before. The dynamic impedance function relations are presented for massless rigid foundations which is possible to obtain dynamic response of foundations for different frequencies and masses accordingly. In this study, the dynamic impedance functions were investigated using physical modeling tests on sandy soil with finite thickness soil stratum over bedrock. The tests were carried out inside a steel container of dimensions 110.8m in length, width and height respectively which was filled into...

Passive and Semi-active Control of Adjacent Buildings Using Friction dampers

, M.Sc. Thesis Sharif University of Technology Ashoori, Morteza (Author) ; Bakhshi, Ali (Supervisor)

Abstract

In this thesis will investigate control performance of coupled buildings. Control of this structures will done using friction dampers based on passive and semi-active strategies.
A numerical study is employed to simulate a coupled building equipped with passive friction damper by using OpenSees software framework.
Semi-active friction damper is used on three groups of adjacent buildings. At first, a mathematical model of coupled buildings is established for each group. The variable friction dampers consist of an actuator, which is based on a piezoelectric stack that alters the normal force at the contact area. A clipping control algorithm considered in the numerical study for the...

Automatic Financial Statement Defect Detection of Publicly-traded Companies

, M.Sc. Thesis Sharif University of Technology Ashoori, Maedeh (Author) ; Habibi, Moslem (Supervisor)

Abstract

Detecting defects in financial statements is crucial because such defects can impact the transparency, accuracy, and reliability of financial reports and influence the decision-making of stakeholders. This study aims to provide a novel approach for identifying defects in the financial statements of companies listed on the Tehran Stock Exchange. In this research, a defect is defined as a difference in data items between audited and unaudited financial statements, which may indicate either unintentional or intentional deviations or signal a potential fraud. The data for this study was automatically collected from the Codal system and includes both audited and unaudited financial reports in the...

EiR: an energy-efficient routing algorithm for delay tolerant networks

, Article 9th International Symposium on Telecommunication, IST 2018, 17 December 2018 through 19 December 2018 ; 2019 , Pages 227-232 ; 9781538682746 (ISBN) Ashoori, M ; Pakravan, M. R ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2019

Abstract

Delay Tolerant Networks (DTNs) are sparse and highly dynamic networks where intermittent connectivity is a common event. In these networks, nodes have time-limited connection opportunity to other moving nodes. Therefore, routing is a major challenge in these networks and researchers have tried to design efficient routing algorithms. Important performance metrics of desired routing algorithms are high delivery probability, low energy consumption and low end to end latency. In this paper, we propose an energy-efficient routing algorithm which is based upon the encounter probabilities of nodes. We use these encounter probabilities to derive a utility metric. Moreover, we utilize assumptions and...

Analysis and Improvement of Energy-Efficient Routing Algorithms for Delay Tolerant Networks

, M.Sc. Thesis Sharif University of Technology Ashoori, Mehri (Author) ; Pakravan, Mohammad Reza (Supervisor)

Abstract

Delay Tolerant Networks (DTNs) are sparse networks in which intermittent connectivity happens due to energy shortage or high mobility and long latency is unavoidable.These networks have a wide range of applications in our daily life such as internet of moving things. In delay tolerant networks, finding an end to end path between source and destination is almost impossible. Therefore, routing can’t be done based on finding an end to end path but it has to be done based on hop by hop sessions. In this thesis, we aim to represent an efficient routing algorithm for delay tolerant networks that can improve delivery probability, delivery cost and delivery latency.Our proposed routing algorithm is...

Power System Load Frequency Control in the Presence of Wind Turbines

, M.Sc. Thesis Sharif University of Technology Ashoori Zadeh, Alireza (Author) ; Ranjbar, Ali Mohammad (Supervisor)

Abstract

This study presents the application of the doubly fed induction generator (DFIG) to reduce the frequency deviation and improve frequency of a power system. This has been done by proposing a wind turbine model and a new fuzzy controller. The fuzzy controller has been suggested to change the speed of the wind turbine rotor and modify the impacts of wind speed fluctuations on the output power. The fuzzy controller parameters are optimized using the genetic algorithm (GA) to achieve the appropriate transient response. A smart controller is combined with fuzzy controller to optimize the usage of wind turbine’s kinetic energy. Furthermore, the DFIG with the proposed controller participates in the...

Introducing a response-based duration metric and its correlation with structural damages

, Article Bulletin of Earthquake Engineering ; Volume 17, Issue 11 , 2019 , Pages 5987-6008 ; 1570761X (ISSN) Mashayekhi, M ; Harati, M ; Ashoori Barmchi, M ; Estekanchi, H. E ; Sharif University of Technology

Springer Netherlands 2019

Abstract

This study proposes a response-based parameter for strong motion duration which is computed for structures and is the total time they are nonlinear during an earthquake. Correlation between structural response and duration for structures, subjected to a set of spectrum matched ground motions, is employed to examine the efficiency of the proposed method. The spectral matching procedure ensures that the influence of amplitude and frequency content of motions on structural response variability is significantly removed. Four concrete building type systems are studied and correlation coefficients of structural response with the proposed duration definition are examined. Comparison of the proposed...

Theoretical and experimental study of foam stability mechanism by nanoparticles: Interfacial, bulk, and porous media behavior

, Article Journal of Molecular Liquids ; Volume 304 , 2020 Suleymani, M ; Ghotbi, C ; Ashoori, S ; Moghadasi, J ; Kharrat, R ; Sharif University of Technology

Elsevier B.V 2020

Abstract

Foam flooding has been applied as a promising method in enhanced oil recovery to obviate the challenges of gas flooding such as fingering, channeling and overriding. However, long-term foam stability is crucial for mobility control. In this work, the effective mechanisms on foam stability in the presence of CaCO3 nanoparticles were assessed both theoretically and experimentally. The static and dynamic behaviors of cationic surfactant (HTAB) foam in the presence of CaCO3 nanoparticles with different hydrophobicity were evaluated. The CaCO3 nanoparticles were treated with a series of long-chain fatty acids to generate a range of wettability. Afterward, the underlying mechanisms were revealed...

Decoding Polar Codes with Deep Learning

, M.Sc. Thesis Sharif University of Technology Ashoori, Mohammad Hossein (Author) ; Behroozi, Hamid (Supervisor) ; Amini, Arash (Supervisor)

Abstract

Polar codes have received much attention to the extent that they are selected as a channel coding scheme in the 5G standard. The successive cancellation list (SCL) decoder suffers from high decoding Latency and limited Throughput due to its sequential decoding nature. Another polar decoding approach is the iterative belief propagation (BP) decoder which is inherently parallel and allows for better Decoding Latency and Throughput. However, its main drawback is an error-correction performance loss compared to the CRC-aided successive cancellation list (CA-SCL) decoder. From previous works, the CRC-aided belief propagation list (CA-BPL) decoder that benefits from the parallel structure of the...

Video Super-Resolution Using Machine Learning

, M.Sc. Thesis Sharif University of Technology Ashoori, Mohammad Hossein (Author) ; Amini, Arash (Supervisor) ; Marvasti, Farrokh (Supervisor)

Abstract

Super-resolution means increasing the resolution so that the quality improves. This is defined for both image and video. In this regard, machine-learning based methods, especially convolutional neural networks, have shown great potential in recent years. Finding the right structure that can deliver high speed and accuracy is the key to solving the super-resolution problem.Despite the myriad of methods for image super-resolution, less attention has been paid to its generalization to video. This generalization should be such that more detail is created in the output using adjacent frames.In this dissertation, the existing methods for image and video super-resolution are reviewed, and then a...

A multi-objective decision-making process of supplier selection and order allocation for multi-period scheduling in an electronic market

, Article International Journal of Advanced Manufacturing Technology ; Volume 52, Issue 9-12 , February , 2011 , Pages 1039-1052 ; 02683768 (ISSN) Fazlollahtabar, H ; Mahdavi, I ; Ashoori, M. T ; Kaviani, S ; Mahdavi Amiri, N ; Sharif University of Technology

2011

Abstract

Supplier selection is a multi-criteria problem which includes both tangible and intangible factors. In these problems when suppliers have capacity or other different constraints, two questions persist: which suppliers are the best and how much should be purchased from a selected supplier? Here, we propose an integrated approach of analytic hierarchy process (AHP), Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS), and multi-objective nonlinear programming to consider both tangible and intangible factors in choosing the best suppliers and define the optimum quantities among selected suppliers to maximize the total value of purchasing and minimize the budget, total...