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pakzad--amin
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Total 250 records
Design of Impedance Surfaces with Metamaterials and Metasurfaces to Implement Line Wave
, M.Sc. Thesis Sharif University of Technology ; Khavasi, Amin (Supervisor)
Abstract
In this thesis we introduce line wave. Which propagates only in one direction and dissipate in other direction. Line wave can propagates at the interface of two complementary impedance surfaces. There are various ways to build a waveguide which can support line waves like complementary structures. In this thesis we try to find a way which will not use complementary structures. Hence we use Spoof Surface Plasmon Polariton concept to mimic complementary structure characteristics. A complementary surface-based waveguide consists of two parts; one part supports TE polarization waves and the other one supports TM polarization waves. When these TE and TM waves face each other in the boundary, line...
BIM Strategic Plan & Vision Development for Transportation Infrastructure Projects in Iran
, M.Sc. Thesis Sharif University of Technology ; Alvanchi, Amin (Supervisor)
Abstract
Transportation infrastructures are vital components of economy, security and welfare of a country. Construction projects of transportation infrastructures in our country are of great importance. Therefore, such projects have always faced with challenges and obstacles on their path to progress. In order that BIM to be accepted and implemented in the Department of Roads and Urban Development of Tehran Province (DRUT), as an organization that supervises and carries out construction projects over Tehran, the organization and its projects have been studied. BIM is defined as a mean to design and create different industrial tasks through modeling technology, interconnected groups of processes and...
Optimal Multi-agent Formation Control of Quadcopters
, M.Sc. Thesis Sharif University of Technology ; Rezaeizadeh, Amin (Supervisor)
Abstract
In today's world, mobile robots have many applications in defense, transportation and industry. A robot may not be able to handle a mission alone or there may be different roles to perform a mission that a robot alone cannot perform, so the need to work with team robots is felt to the Necessary that by development Robot Technology and Advances in Communication, Microelectronics, Computing Technology, and Multi - Factor Expansion, robotic systems are widely used in theoretical research due to their flexibility, robustness, and scalability. In this research, robots are controlled in a coordinated manner as a team. In this research, algorithms were developed so that in a two and...
PID Auto-Tuning and Flight Trimming for the Quadcopters by Deep Reinforcement Learning and Digital Twin Technology
, M.Sc. Thesis Sharif University of Technology ; Rezaeizadeh, Amin (Supervisor)
Abstract
In recent years with the development of industrial automation, artificial intelligence, and the coming of the fourth-generation industrial revolution, making robots intelligent and solving old challenges in non-linear systems in order to make human life easier has always been the point of view of researchers. Flight systems are always considered to be one of the most nonlinear systems. In linear systems, a PID controller can be easily designed and implemented; But in non-linear systems, because the set point is constantly changing, the PID gain must be manually adjusted by the operator, which is almost impossible in practice; Therefore, finding a fast and efficient way to solve this...
Investigating Implementation of Building Information Modeling (BIM) Applications in Building Construction Projects in Iran
, M.Sc. Thesis Sharif University of Technology ; Alvanchi, Amin (Supervisor)
Abstract
Construction is a key industry with significant impacts on the country’s economy. This industry, however, suffers from high rework, increased cost, prolonged delay, and decreased quality. The invention of building information modeling (BIM) in recent decades has opened new windows for improving performance in this industry. The complexity involved in this novel technology requires a tailored execution plan for its successful implementation in construction projects in Iran. Here, the development of properly prepared operational BIM implementation guidelines plays an important role. These operational guidelines, however, still are missing for construction projects in the country. To address...
Developing an Interactive Simulation Environment for Improving Time and Cost Planning of Building Projects using Combined BIM-VR Technologies
, M.Sc. Thesis Sharif University of Technology ; Alvanchi, Amin (Supervisor)
Abstract
Despite advancements in Building Information Modeling (BIM) in the construction industry, issues such as the intangibility of building models and a lack of interaction and opinion-sharing still exist. The integration of Virtual Reality with BIM has rectified these problems. Quantity surveying, material estimation, solving design problems during modeling and preparing a building model containing information are some of the advantages of using BIM in this research. Alongside BIM, VR tools were employed as a mean to increase interaction with the user, boost marketing and pre-sales, create alternative options for building components, and estimate cost and time. Following the development of a...
Semisolid Microstructure Evaluation of M2 High Speed Steel by Cooling Slope and Rolled - Annealed
, M.Sc. Thesis Sharif University of Technology ; Aashuri, Hossein (Supervisor)
Abstract
In this research the effects of cooling slope angle and the temperature of molten steel on globular structure after holding the samples at semisolid state have been investigated. The globular structure of high speed steel in the form of rolled - annealed and as cast condition, has been investigated in the semisolid state. The results showed that the grain sizes of cooling slope samples were lower than the rolled- annealed samples after holding at semisolid temperature. On the other hand, rolled-annealed solid grains had better roundness compared with cooling slope samples. Dissolution of carbides in the austenite phase at grain boundary leads to formation of globular particles in the...
Atom Transfer Radical Polymerization of Acryl Amide in Reverse Suspension
, M.Sc. Thesis Sharif University of Technology ; Pourjavadi, Ali (Supervisor)
Abstract
Atom transfer radical polymerization (ATRP) is a convenient approach to synthesis of polymer with narrow molecular weight distribution. ATRP of acrylamide (AAm) is taken into consideration because of the intrinsic properties of acrylamide such as water solubility and biocompatibility. As reported in many recent works, polymerization of acrylamide by this method didn’t provide monomodal molecular weight distributions. In best condition with strong ligands such as Me4Cyclam, polymerization was carried out in a short time with high yield but polymerization was not highly controlled. It was shown that polymerization of acrylamide under typical ATRP condition displayed a much lower ATRP...
Multiview Localization and Tracking of Soccer Players and Ball
, M.Sc. Thesis Sharif University of Technology ; Kasaei, Shohreh (Supervisor)
Abstract
By progress of computer vision, many systems are produced for soccer analysis. These systems have been used in many applications such as 2D and 3D reconstruction in arbitrary view. In this circumstance, we need to detect and track players, referee and ball in whole matches. In a single view system there are problems such as occlusion. By having more views of game, when two objects are occluded in one view, we can detect and track them in the others. Objective of this project is multi-view detection and multi-view tracking players and ball in soccer. In recorded videos from multiple views, we track path of players and the ball.
Proposed player tracking system has two main parts. First...
Proposed player tracking system has two main parts. First...
Study of Invariants of Diophantine Forms and Equations
, M.Sc. Thesis Sharif University of Technology ; Jafari, Amir (Supervisor)
Abstract
The aim of this thesis is to study invariants of Diophantine forms and equations. These invariants are the transformations that do not change the original equations and forms. This thesis has a different view to the concept of invariants from Hlibertian view. Based on this new definition, by having one of the solutions of the equation, new solutions can be found with invariant method. The number of these solutions can be finite or infinite. In case of infinite solutions this method is more important. The focus of this thesis is on forms and linear invariants. The most important result in this text is about two main theorems that can classify the invariants of all completely decomposable...
Improved Model Order Reduction of LTI Systems with Using LMIs
, M.Sc. Thesis Sharif University of Technology ; Nobakhti, Amin (Supervisor)
Abstract
Order reduction is a very important issue in Control Theory. A growing need for order reduction models in different fields such as simulation, identification, and design of control system shows this significance. Actually, a high-order system makes a great deal of complexity in designing hardware of control system, debugging, and implementation. Till nowadays, many repetitive as well as nonrepetitive methods with various criteria have been introduced to find low-order models. In this research, order reduction of linear time invariant system models is analyzed. The selected criterion for measuring error between original system and reduced order system is the norm of H1 because it is not only...
A Study of Weather Change Impacts on Construction Projects in Iran
, M.Sc. Thesis Sharif University of Technology ; Alvanchi, Amin (Supervisor)
Abstract
Several factors can cause an effect on the overall efficiency of construction projects, especially because most of these projects are being hold outdoors. Recognizing these factors can help the project to increase its efficiency and also help the managers and the schedule planners to set their aims more accurately. One of the most important factor which affects the project efficiency is the climate change and weather. The aim of this project is to help the planner and the main subject of this project is providing a guideline for the planners and managers of construction projects about the effects of weather and climate change on the schedule and the estimation of the budget of the project...
Designing a Low Power Receiver for Medical Implant Communications Service
, M.Sc. Thesis Sharif University of Technology ; Safarian, Amin Ghasem (Supervisor)
Abstract
One of the most important parameters of implanted chip in body is its ability to work for a long time without the need for battery change. Hence designing radio frequency transceivers used in these chips should be done with the lowest possible power consumption. Of course it should be noticed that for correct communication, standard specifications must be meeted. In this thesis, a receiver in medical implant communication service standard with the goal of minimal power consumption is designed. In circuit design different challenges such as low inductor quality factor, threshold voltage of transistors and usual trade-offs between receiver parameters are faced. Therefore, previous used...
Synthesis of Magnetic Nanocarriers Based on Coating of Fe3O4 with Modified Biodegradable Polysaccharides by pH Sensitive Agents for Targeted Release of Anticancer Drug Doxorubicin
, M.Sc. Thesis Sharif University of Technology ; Pourjavadi, Ali (Supervisor)
Abstract
One of the major problems in cancer treatment is the side effects of the drugs. Nowadays, scientists are developing smart nanocarriers which used for diagnosis and delivering drugs in order to circulate through blood vessels, pass the immune system, attach to cancer cells and kill them without any side effects. In the first research of this thesis, magnetic nanoparticles were coated by modified alginate and used as smart nanocarriers. Magnetic nanocarrier were sysnthesized based on hydrophobic coating of oleic acid and hydrazine oleate-modified alginate shell. The resulting carrier is pH-sensitive and the alginate shell removes in the low pH medium. DOX was placed between hydrophobic chains....
Fixed Order Controller Design Via Convex Optimization
, M.Sc. Thesis Sharif University of Technology ; Nobakhti, Amin (Supervisor)
Abstract
In this thesis we introduce a new methodology to solve the problem of multi-objective control design of linear output-feedback with a constraint on the order of controller. This problem can be formulated as a set of linear matrix inequalities and an additional rank constraint. This constraint is highly non-convex and makes this optimization problem NP-hard. The proposed methodology results in methods which are multi-step and in each step a convex optimization problem shall be solved. This methodology can consider any combination of different design objectives such as H2 performance, H1 performance, passivity and regional pole assignment. In the development of described methodology, a...
Implementation of Compaction Meter with Controller Design and Simulation
, M.Sc. Thesis Sharif University of Technology ; Nobakhti, Amin (Supervisor)
Abstract
There are a lot of ways to measure the soil compaction but all of them have some deficiencies like low precision, soil destructive, time consuming and etc. The usual ways to measure the compaction in Iran are so traditonal and have the above problems. To solve these problems, modern ways like intelligent compaction is recomonded to decrease the time and cost of compaction. The observor can also control the compaction of all the soil point to prevent any offenses by making the network between the rollers.In new methods the soil compaction is calculated by measuring the roller vibratory and usage of fourier transform from the drum response . To compact the soil more precisely and more quickly,...
Soil Moisture Monitoring in Precision Agriculture Using Estimation Theories
, Ph.D. Dissertation Sharif University of Technology ; Nobakhti, Amin (Supervisor)
Abstract
Monitoring of soil moisture plays an essential role in correct decision making and implementation of any closed loop control system in precision agriculture. On the one hand, continuous using of a lot of moisture sensors and monitoring of soil moisture via direct measurement is restricted by practical prohibitions. On the grounds that activation of a lot of sensors continuously requires communication of a large amount of information and causes high power consumption for a moisture monitoring system. On the other hand, using remote sensing methods such as satellite methods, for moisture monitoring in arbitrary spatial and time resolution for control purposes, is not practically possible. The...
Understanding Work Force Absenteeism Structure in Contractor Companies in Iran
, M.Sc. Thesis Sharif University of Technology ; Alvanchi, Amin (Supervisor)
Abstract
Recent researches on productivity in different industries has showed that there is a significant lack of growth of productivity in construction industry among other industries. It means that in other industries by appling the solutions that have been concluded from researches in those industries, the productivity in those industries had a great growth through these years. There have been some researches on the construction industry problems and productivity growth obstacles and some remedies have been suggested. Construction industry despite other industries has great dependency on labor productivity, so with growth in labor productivity we can have great influence on construction projects...
Predicting Usefulness of Code Review Comments Using Machine Learning Algorithms
, M.Sc. Thesis Sharif University of Technology ; Fazli, Mohammad Amin (Supervisor)
Abstract
The competition for staying in the business world has intensified today with the rise of open-source and commercial software. As long as a software is tailor-made to suit the needs of users, it is so-called alive and can stay in the competition. So the maintenance phase is necessary to make changes to the software to meet the needs of users. To reduce costs associated with this phase, it is necessary to avoid software bugs. One way to avoid software bugs is to use peer code review. Peer code review has been recognized as one of the best software engineering principles of the last 35 years. This principle helps maintain the quality of the code due to changes made to parts of the code that...
Developing a Semi-automated Framework for Procurement Planning Using BIM in order to Optimize Project Cost
, M.Sc. Thesis Sharif University of Technology ; Alvanchi, Amin (Supervisor)
Abstract
Procurement management is one of the main knowledge areas of project management which is of high importance. Traditionally, procurement of construction projects is hard and time-consuming. With the advent of building information modeling and the capabilities that it provides tp project managers, procurement management of project can be facilitated. In this research, a semi-automated framework based on BIM is presented to improve procurement planning process of construction projects in Iran. In this regard, by identifying the capabilities of BIM as well as the limitations of procurement system of construction projects, this research has provided a framework to semi-automatically generate the...