Thermal Simulation of Sponge Iron Production by Höganäs Method

, M.Sc. Thesis Sharif University of Technology Akbarian, Amir Hassan (Author) ; Halali, Mohammad (Supervisor)

Abstract

Sponge Iron production is conducted in various methods that one of them is using coal as a reduction agent. Hoganas process is a different coal-based method that has not been investigated in details. Therefore, the heat transfer method in the system is one of the basic steps to a better recognition of this process (with special Hoganas charging). The present paper investigates the temperature distribution method in the Hoganas cylinder through a numerical model using finite elements. The effects of different parameters, namely preheating and porosity were studied on ceramic crucible made from silicon carbide and it was observed that the consumption energy decreases with the increase of...

The Assessment of Cyber_Attacks on Electric Vehicles Charging by a Microgrid (Bus and Personal Vehicle)and Examining the Relevant Consequences in the Power Distribution Grid

, M.Sc. Thesis Sharif University of Technology Akbarian, Amir Hossein (Author) ; Vakilian, Mehdi (Supervisor)

Abstract

Todays, thanks to the positive effects of electric vehicles, (against the vehicles which use patrol as their fuel), reduction of the Earth temperature and its climate change; the manufacturing, sale and use of electric vehicles experience a sharp increase. In addition to decreasing the air pollution, due to their abundant smart implications, they have been dramatically propagated. Massive use of these devices has raised the concern about the loss of the security which is indispensable part of the infrastructure. None of the past publications and works have taken the cyber-attack on the charging price rate and other data into account. In this thesis, charging methods of electric vehicles are...

Functional Connectivity Network in Rest-State fMRI Baseline in High Functioning Autism Disorder

, M.Sc. Thesis Sharif University of Technology Akbarian Aghdam, Amir (Author) ; Fatemizadeh, Emad (Supervisor)

Abstract

Autism spectrum disorders (ASD) have been defined as developmental disorders characterized by abnormalities in social interaction, communication skills, and behavioral flexibility. Over the past decades, studies using various genetic, neurobiological, cognitive and behavioral approaches have sought a single explanation for the heterogeneous manifestations of ASD, but no consensus on the etiology of ASD has emerged. Further studies aim to clarify the mechanism of disease.
Functional Magnetic Resonance Imaging (fMRI) is a new way of imaging which evaluates activity of brain by measuring magnetic difference caused by oscillation in blood oxygen level. fMRI has been widely used in recent...

Vulnerability of EV charging stations to cyber attacks manipulating prices

, Article 2023 International Conference on Future Energy Solutions, FES 2023 ; 2023 ; 979-835033230-8 (ISBN) Akbarian, A ; Bahrami, M ; Vakilian, M ; Lehtonen, M ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2023

Abstract

Electric vehicles (EVs) have experienced an unprecedented increase in their penetration; in well developed countries; due to the advancement of battery technology and the need to make transportation more environmentally friendly. As a result of this trend, EVs have become an integral part of those countries power grid ecosystem, where they may be used as both a source, and a consumer of energy. However, cybersecurity risks associated with large fleets of EVs within the power grids can significantly impact the normal operation of distribution systems. This paper considers the cyber-attack consequences, from attackers' perspective. The cyber attackers under study target the charging price (CP)...

Design and Implementaion of a Web Application Honeypot

, M.Sc. Thesis Sharif University of Technology Ali Akbarian, Amir Hossein (Author) ; Kharrazi, Mehdi (Supervisor)

Abstract

With the rapid growth of Internet popularity, web applications are growing in usage and complexity, and therefore, are attractive targets for attackers. Increasing number of services and amount of information stored in the Internet, stimulates attackers to focus on these kind of applications. On the other hand, security specialists are deploying different solutions to mitigate such threats. One of these solutions are Honeypot systems. In contrast with other security solutions, honeypots are not designed to defend against attackers directly. Honeypots, rather, are planned to gather data about what attackers do. This information can help security administrators to learn and understand...

Hydraulic Evaluation and Pressure Estimation in Two-Phase Air-Water Slug Flow Using Soft Computing

, M.Sc. Thesis Sharif University of Technology Akbarian, Hadi (Author) ; Borghei, Shamsai (Supervisor) ; Shamsaee, Abolfazl (Co-Advisor)

Abstract

Study of hydraulic characteristics of two-phase flow is one of the important issues in hydraulic engineering. Two-phase flows usually accur in hydraulic structures such as pressurized flow tunnels, culverts, sewer pipes, junctions, and similar conduits. Under certain conditions, air may also be introduced into pressurized intake systems, which may form large bubbles in portions of the pipe. The bubbles may, in turn, cause an unstable slug flow, or other flow patterns. Slug flow is one of the most probable patterns in these flows. Prediction of pressure in this situation is a complex subject which despite its great importance is rarely discussed. In this study, the results of a laboratory...

Continuous Transition from Self-organized Criticality to Self-organized Bistability

, M.Sc. Thesis Sharif University of Technology Ali Akbarian, Mohammad Navid (Author) ; Moghimi Araghi, Saman (Supervisor)

Abstract

”Self-organized criticality” is a conceptual term that has helped us describe cer- tain critical behaviors in nature over the past approximately thirty years. In systems exhibiting this characteristic, critical behavior emerges without the need for external parameter adjustments. The necessary mechanism to observe such phenomena is for the critical point to be a dynamical attractor. Based on this, other phenomena have been proposed in which the critical point is not an attractor; instead, a stable cycle forms around it. This mechanism has led to the emergence of a new concept known as ”self- organized bistability.” The primary model proposed for such a phenomenon is based on a sandpile...

Advances in heuristic signal processing and applications

, Book ; Chatterjee, Amitava ; Nobahari, Hadi ; Siarry, Patrick

Springer 2013

Abstract

There have been significant developments in the design and application of algorithms for both one-dimensional signal processing and multidimensional signal processing, namely image and video processing, with the recent focus changing from a step-by-step procedure of designing the algorithm first and following up with in-depth analysis and performance improvement to instead applying heuristic-based methods to solve signal-processing problems. In this book the contributing authors demonstrate both general-purpose algorithms and those aimed at solving specialized application problems, with a special emphasis on heuristic iterative optimization methods employing modern evolutionary and swarm...

Development of an Evolutionary Algorithm Based on Surrogate Models to be used in Multi-disciplinary Design Optimization of a Flying Vehicle

, M.Sc. Thesis Sharif University of Technology Ghoreishi, Mohaddeseh (Author) ; Nobahari, Hadi (Supervisor)

Abstract

In this research, multi-disciplinary design optimization (MDO) of a flying vehicle has been done based on the flight simulation. A meta-heuristic algorithm called Multi-objective Adaptive Real-coded Memetic Algorithm (MARCOMA) has been used for optimization. Since solving a MDO problem is a time consuming process, a RBF neural network has been used in the optimization algorithm as a surrogate model. The new algorithm, called MARCOMA+NN, has been tested with some standard benchmarks. MDO problem has six disciplines consists structure, aerodynamic, propulsion, guidance, control, and fire control. The MDO problem has 31 design variables and two objective functions. The objective functions are...

Optimal Design and Real-time Implementation of a Cooperative Guidance Algorithm against a Flying Vehicle

, M.Sc. Thesis Sharif University of Technology Motie, Mahyar (Author) ; Nobahari, Hadi (Supervisor)

Abstract

A cooperative aerial system to defense a Ground Station (GS), against an Incoming aerial Targets (IT) is presented. GS is surrounded by given terrains and a group of homogenous Unmanned Aerial Vehicles (UAVs) are employed using a novel online guidance algorithm in a decentralized manner. The proposed algorithm includes loiter, midcourse and terminal phases. During loiter; UAVs follow an optimal circular path. IT is supposed to approach GS along an optimal low altitude trajectory with respect to the terrains. UAVs are informed the initial position and velocity of IT and they are unaware of IT trajectory. Each UAV decides on whether to engage with IT or not, and shares its decision with other...

Synthesis and Characterization of PVDF Magnetic Nanocomposite

, M.Sc. Thesis Sharif University of Technology Hadi, Mina (Author) ; Forounchi, Massoud (Supervisor)

Abstract

PVDF (polyvinylidene fluoride) magnetic nanocomposite films were prepared by solution casting using two types of nanomagnetic particles: (i) magnetic nanoparticles synthesized by using an alkaline solution of mixed ferrous/ferric salts along with oleic acid as a coating agent at 70˚C; (ii) Fe3O4 nanoparticles prepared by hydrolysis of aqueous solution of ferrous/ferric salts with potassium hydroxide at room temprature. Scanning electron microscopy (SEM) showed that the PVDF magnetic nanocomposite had a porous structure with Fe3O4 nanoparticles dispersed inside the porous polymer matrix. The presence of crystalline magnetite within the polymer matrix was confirmed by X-Ray diffraction method...

Cooperative Search and Localization of Mobile RF Ground Targets, Using a Group of UAVs

, M.Sc. Thesis Sharif University of Technology Effati, Meysam (Author) ; Nobahari, Hadi (Supervisor)

Abstract

In this project, a method for cooperative search and localization of RF ground moving targets by a group of UAVs is developed. It should be noted that UAVs are just equipped with GPS and directional sensors. Since there is fuel constraint for UAVs, they take fuel from a tanker whenever they require. Moreover, searching method enables the UAVs to see different parts of the desired area with almost uniform distribution. In addition, the proposed approach enables the UAVs to perform a local search with the aim of finding the targets having lost their signal during localization mode. Finally, based upon a fueling decision function the UAVs take turn, approach to the fuel tanker, and start...

Attitude Control of a 3DOF Quadrotor Stand Using Intelligent Back-stepping Approach

, M.Sc. Thesis Sharif University of Technology Abeshtan, Peyman (Author) ; Nobahari, Hadi (Supervisor)

Abstract

In this research a novel intelligent back-stepping control method is developed. This method is robust to sensor noise and external disturbances. In addition, the controller is robust under model uncertainty. This controller does not need precise knowledge of system parameters. This method is based on three methods of: back-stepping control, least squares estimation and a fuzzy compensator. This controller is used to control quadrotor stand witch is like an inverse pendulum. In quadrotor stand modeling, the inverse pendulum effect is considered too, witch is one of the innovations of the research. By doing various simulations, the validity of controller is tested. Also the performance of the...

Cooperative Search and Localization of Aerial Targets, Using a Group of Fixed Wing UAVs

, M.Sc. Thesis Sharif University of Technology pourhaji, Amir (Author) ; Nobahari, Hadi (Supervisor)

Abstract

Topic that is investigated in this article include identify and localization a number of aerial target penetrating into a protected by area by a swarm of UAVs is fixed wing. UAVs do not have any prior notice of positioning targets. In addition, it is assumed that lacks any radiation exploitable targets and thus use UAVs for Targets Detection from an active radar system. Obviously this article focus on developing a guidance algorithm UAVs to this particular issue and also as the targets participatory is localization algorithm. In addition, extraction type and performance characteristics radar system required and also performance characteristics of the class of UAVs, which is suitable to...

A New Method for Integrated Controller and Observer Design of a Nonlinear System Using Genetic Programming

, M.Sc. Thesis Sharif University of Technology Khosroabadi, Saleh (Author) ; Nobahari, Hadi (Supervisor)

Abstract

The purpose of this paper is to design an integrated controller and observer (ICO) for a nonlinear system using genetic programming. ICO is a function that constructs control command directly from the measured state variables of the system. It means that, this function should imitate the behavior of the observer and controller and control the system with acceptable performance in different initial conditions, at the presence of disturbances and system uncertainties. The complexity of this design method, is not related to the complexity of the plant, in fact, the complexity in plant just effects at run time, but the design procedure does not change. So, if exact model of plant exist, using...

Development of Integrated Model of the Wastewater and Organic Solid Waste Flows to Minimize Environmental Impacts and Maximize Energy Recovery for a Residential Building

, M.Sc. Thesis Sharif University of Technology Hadi, Hamid (Author) ; Avami, Akram (Supervisor)

Abstract

Nowdays much of the organic solid waste and wastewater is buried using centralized and traditional methods. This leads to many problems, including groundwater pollution, methane emissions into the atmosphere and rapid transmission of disease. In order to avoid these problems, using a decentralized approach can be a good solution. In this study, recovery of organic waste and wastewater of residential buildings using anaerobic digester as a decentralized way, have been examined. Using experiments, the optimum mass ratio of organic solid waste and wastewater is obtained as 80% and 20% respectively. Biogas production model is developed using mass balance and Balance of electrons in redox...

Parallel Multi-disciplinary Design Optimization of a Guided Flying Vehicle

, M.Sc. Thesis Sharif University of Technology Darabi, Davoud (Author) ; Nobahari, Hadi (Supervisor)

Abstract

Multi-disciplinary design optimization (MDO) of a surface to air flying vehicle has been done in this research, on the basis of flight simulation. The MDO problem have five disciplines consists of aerodynamic, propulsion, guidance, control, and fire control. Multiple campaign scenarios are defined. The MDO problem has 31 design variables and two objective functions. The objective functions are flying vehicle weight and miss distance. A new meta-heuristic algorithm has been designed to solve multi-objective optimization problems. The new algorithm has been called Multi-objective Adaptive Real-coded Memetic Algorithm (MARCOMA). The MARCOMA can solve large-scale and multi-objective problems and...

Dynamic Modelling and Nonlinear Control of a Hybrid Powered Hexarotor for Precise Trajectory Tracking

, M.Sc. Thesis Sharif University of Technology Saadat, Sepehr (Author) ; Nobahari, Hadi (Supervisor)

Abstract

In this Thesis, an unmanned multicopter with a new structure is modeled and a nonlinear controller is designed for it to track the trajectories precisely. The multicopter in this thesis, has six propellers with a hybrid propulsion system (a combination of fuel and electric propulsion system) that has the ability to carry more payload and maintain more flight duration compared to electric multicopters. In the beginning, the performance characteristics and technical specifications of the hexacopter are presented. For modeling, first the equations of six degrees of freedom movement of the hexacopter are derived by the Newton-Euler method. In the next step, the forces and torques applied to the...

Theoretical Investigation of Ab-initio MD Approach to Increase the Efficiency and Accuracy of VCD Spectrum Calculation

, M.Sc. Thesis Sharif University of Technology Hadi, Hossein (Author) ; Jamshidi, Zahra (Supervisor)

Abstract

Understanding of the Molecules is the main purpose of the chemistry. Ab-initio molecular dynamics (AIMD) as a branch of the computational chemistry, tries to give us a deep comprehension of the molecule, and its chemical, physical and optical activities. This comprehension, relies on the accuracy of quantum mechanics, in addition to the speed of the classical mechanics. The mixing of the quantum mechanics and the classical mechanics could simulate activities of the atoms in the time-domain, provided the mixing is done with precaution. This, in turn, helps us to forecast the response of a molecule in different situations, and also translating the macroscopic phenomena in a nanoscopic...

Developing a Heuristic Filter Utilizing Firefly Optimization Algorithm: A Case Study on State Estimation of a Slung Payload from a Quadrotor

, M.Sc. Thesis Sharif University of Technology Raoufi, Mohsen (Author) ; Nobahari, Hadi (Supervisor)

Abstract

The aim of the present thesis is to develop a novel heuristic filter by utilizing Firefly Optimization Algorithm for state estimation of nonlinear, non-Gaussian systems. The proposed filter formulates the estimation problem as a dynamic, stochastic one. The swarm intelligence of the fireflies enables the filter to find and track the best estimation. To estimate the states of a system, the model of the system is required. Hence, an 8-DoF quadrotor with slung payload system, as a case study, is modeled by the tensor method. In this case, as a highly nonlinear system, in order not to rely on extra sensors for monitoring swing-angle, the estimation of payload states is needed. In this regard,...