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mohammadpour--iman
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Influence of energy band alignment in mixed crystalline TiO2 nanotube arrays: Good for photocatalysis, bad for electron transfer
, Article Journal of Physics D: Applied Physics ; Volume 50, Issue 50 , 2017 ; 00223727 (ISSN) ; Sharif University of Technology
2017
Abstract
Despite the wide application ranges of TiO2, the precise explanation of the charge transport dynamic through a mixed crystal phase of this semiconductor has remained elusive. Here, in this research, mixed-phase TiO2 nanotube arrays (TNTAs) consisting of anatase and 0-15% rutile phases has been formed through various annealing processes and employed as a photoelectrode of a photovoltaic cell. Wide ranges of optoelectronic experiments have been employed to explore the band alignment position, as well as the depth and density of trap states in TNTAs. Short circuit potential, as well as open circuit potential measurements specified that the band alignment of more than 0.2 eV exists between the...
Flexible triboelectric nanogenerator based on high surface area TiO2 nanotube arrays
, Article Advanced Engineering Materials ; Volume 20, Issue 5 , May , 2018 ; 14381656 (ISSN) ; Sharif University of Technology
Wiley-VCH Verlag
2018
Abstract
Triboelectric nanogenerators (TENGs) can harvest mechanical energy through coupling triboelectric effect and electrostatic induction. Typically, TENGs consist of organic materials, however on account of the potentially wide range of applications of TENGs as the self-powered portable/wearable electronics, biomedical devices, and sensors; semiconductor metal oxide materials can be promising candidates to be incorporating in TENG structure. Here, flexible TENG based on self-organized TiO2 nanotube arrays (TNTAs) is fabricated via anodization method. The introduced flexible large area nanotubular electrode is employed as the moving electrode in contact with Kapton film in vertical contact...
Designing a Vehicle Counting and Classification System
, M.Sc. Thesis Sharif University of Technology ; Gholampour, Iman (Supervisor)
Abstract
In recent years, Intelligent Transportation Systems (ITS) have received special attentions both in research and in commercial areas. Increased infrastructure facilities, like surveillance cameras, has made this concept even more attainable than before. In this respect, the ability to automatically extract information from traffic images, as one of the key inputs of ITSs, is of great importance. With an increased number of surveillance cameras and the need for more accurate information regarding the road users and their interactions, in order to better city traffic management, building and repairing roads, trip time estimation, number of people per roads estimation and etc, using human...
Economic Model Predictive Control with Time Varying Constraints
, M.Sc. Thesis Sharif University of Technology ; Haeri, Mohammad (Supervisor)
Abstract
In today's world we are dealing with many devices and processes with the goal of efficiency and performance improvement. In many processes particularly chemical ones, the goal is to control the output according to its constraints in the way that the performance is economically efficient, such as reducing energy consumption and energy loss and increasing efficiency. In order to control a process with economical goals, an economical cost function is used and after determination of optimal values a controller is used to guide the process so can achieve them. Model predictive control (MPC) is very common in this economic control Due to advantages such as considering the problem constraints. In...
Blind Universal Steganalysis in Multiple Actor Paradigms and its Relation to Pixel-Cost
, M.Sc. Thesis Sharif University of Technology ; Gholampour, Iman (Supervisor)
Abstract
Steganography is method for communicating confidential information through a non-trustworth in way which hides the existence of communication. For improving the security of steganography statistical detectability must decrease as such as possible. Despite the fact, that the quality of the relation between statistical detectability and amount of distortion engendered by embedding is still an open problem, problem of detectability reduces to problem of management of pixel embedding in order to minimization of distortion. As in wet paper coding methods, an optimum (or approximately optimum) algorithm proportioned to Pixel-cost has been offered, the current problem of steganography is to find...
Embedded Camera Design for Machine Vision Traffic Aplication
, M.Sc. Thesis Sharif University of Technology ; Gholampour, Iman (Supervisor)
Abstract
With the advent of technology, small in size sensors, memory, speeding up the processor and lowering the cost, it is possible to build an embedded camera system. The goal of this project is to design and build an embedded camera system so it can execute any set of necessary algorithms as depending on the application. In this project, two models of embedded camera systems have been presented as an integrated system and a system with independent units. To design the integrated embedded system, ZYNQ processor is used and two structures are presented in the form of hardware-software and hardware design. In hardware-software design, image processing operations are done by software and in hardware...
Activity Analysis Based on Mobile Sensors
,
M.Sc. Thesis
Sharif University of Technology
;
Gholampour, Iman
(Supervisor)
Abstract
Smartphone sensors like accelerometer, gyroscope and magnetometer are very common nowadays. This gives us the opportunity for sensor-based activity recognition. This thesis's goal is to collect data from different smartphone sensors and then extract hand-crafted features and classify them using machine learning algorithms. Metro, bus, taxi, bicycle, running, upstairs, walking and standing are studied activities in this thesis. All above steps are covered in this research, later we want to present an activity recognition model and then test it through a web server, after that, we modify the model by proposing to change learning coefficient to gain better accuracy. Finally, an Android app was...
Design and Development of Indoor Tracking and Navigation IoT Systems
,
M.Sc. Thesis
Sharif University of Technology
;
Gholampour, Iman
(Supervisor)
Abstract
Current Global Positioning Systems (GPS) are unreliable for indoor positioning, leading to an increased demand for indoor navigation and tracking services. This research utilizes wireless technologies such as Bluetooth and Wi-Fi to provide these services by installing devices in the environment that connect to objects or individuals. To ensure the system's practicality, attention must be given to hardware optimization, cost reduction, and easy installation. The system should be applicable in large indoor environments such as hospitals and buildings, assisting with navigation. Key challenges include positioning accuracy, implementation costs, and energy consumption. This thesis presents...
Investigating How Network Effect, Affect the Success of Platform Complements in the Video Game Industry
, M.Sc. Thesis Sharif University of Technology ; Miremadi, Iman (Supervisor)
Abstract
This research examines the impact of indirect network effects in platforms on the likelihood of success for platform complements. The main question addressed by this study is: How does a larger number of complements in a platform ecosystem, through access to diverse resources and knowledge, influence the enhancement of innovation and the likelihood of success for platform complements? While the expansion of indirect networks creates more opportunities for innovation and access to resources on one hand, it may also lead to negative effects such as increased competition among complements and user confusion on the other. The goal of this research is to provide a comprehensive answer to these...
Examining the Effect of Patent Registration on the Attraction of Venture Capital: the Moderating Role of Collaborative Patents In the Field of Artificial Intelligence
,
M.Sc. Thesis
Sharif University of Technology
;
Miremadi, Iman
(Supervisor)
Abstract
Artificial intelligence is a field that has made another revolution in the Fourth Industrial Revolution and has become one of the most widely used emerging technologies in the present era. Further investigation of the trends in this field shows that it has shown increasing growth in recent years. Also, in the future, this trend will continue and fundamental changes will occur in societies. For this reason, countries must definitely pay the necessary and sufficient attention to this field in their growth and development path. To achieve this growth path, it is intended to evaluate the status of leading countries in the field of artificial intelligence using two key variables in technological...
The Impact of Digital Technologies on CO2 Emissions: A Comparison between Developed and Developing Countries
, M.Sc. Thesis Sharif University of Technology ; Miremadi, Iman (Supervisor)
Abstract
The importance and vitality of focusing on sustainable transition and reducing carbon dioxide emissions are clear to everyone today. However, until recently, the impact of digitization as a major global trend involving the application of digital technologies to change and optimize various elements of business, society, and daily life on the environment and carbon dioxide emissions has been underestimated. Despite the growing amount of research in this field, according to current studies, the connection between digitization and carbon dioxide emissions is not clear. To achieve environmental and sustainable development goals, fossil fuel consumption and greenhouse gas (GHG) emissions must be...
The effect of Information and Communication Technologies Use on Disease Burden in Countries
, M.Sc. Thesis Sharif University of Technology ; Miremadi, Iman (Supervisor)
Abstract
Researchers are continuously investigating the factors influencing the burden of disease. Studying these factors contributes to improving the health status of communities. Although previous studies have addressed the impact of digital technologies on health improvement, the effect of information and communication technology (ICT) usage on the disease burden in countries has not been empirically studied. Therefore, this study examines this impact and considers the level of development of countries as a moderating factor. Results from a panel data set of 1,079 observations across 83 countries over 13 years indicate that the use of information and communication technology reduces the disease...
Efficient nanostructured biophotovoltaic cell based on bacteriorhodopsin as biophotosensitizer
, Article ACS Sustainable Chemistry and Engineering ; Volume 3, Issue 5 , March , 2015 , Pages 809-813 ; 21680485 (ISSN) ; Janfaza, S ; Sharif University of Technology
American Chemical Society
2015
Abstract
Here, we report on utilizing a photoactive protein, bacteriorhodopsin (bR), as a light harvester in combination with TiO2 nanoparticles in biosensitized solar cell application. Experiments have been conducted to investigate the capability of surface adsorption of bR on nanoparticular TiO2 photoanodes. Different pretreatment processes have been done to modify the interface of TiO2 nanoparticles and bR as a biophotosensitizer. Our results indicate the feasibility of efficient immobilization and photoinduced charge transfer of bR to the nanostructured TiO2 photoelectrode. Under illumination of simulated AM1.5 sunlight, the solar-light-to-electricity...
Numerical study of the effect of vascular bed on heat transfer during high intensity focused ultrasound (HIFU) ablation of the liver tumor
, Article Journal of Thermal Biology ; Volume 86 , 2019 ; 03064565 (ISSN) ; Firoozabadi, B ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
In this study, the influence of vascular bed comprising terminal arterial branches on heat transfer in a liver tumor exposed to high intensity focused ultrasound (HIFU) is studied numerically. Also, the effect of vascular density on temperature distribution is investigated. A coupled set of acoustics, thermal, and fluid models is used to calculate the temperature distribution in the liver. The numerical model is established based on the Westervelt and bioheat equations along with the Navier-Stokes equations. Moreover, the acoustic streaming effect is included with Newtonian and non-Newtonian flow assumptions. It is found that in a vascular bed comprising terminal arterial branches, the...
High intensity focused ultrasound (HIFU) ablation of porous liver: numerical analysis of heat transfer and hemodynamics
, Article Applied Thermal Engineering ; Volume 170 , April , 2020 ; Firoozabadi, B ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In the present study, the influence of the liver vascular bed on heat transfer in a tumor located close to the hepatic artery and exposed to high intensity focused ultrasound (HIFU), is studied numerically. For this purpose, an acoustics-thermal-fluid coupling model based on the porous media theory under the local thermal non-equilibrium assumption is used to calculate the temperature field in the tumor, porous liver, and the hepatic artery. Different generations of the liver vasculature including arterial branches, terminal arterial branches, terminal veins and venous branches are examined at different porosities (the volume fraction of the vasculature). It is found that the liver...
Evaluation of the Hydrodynamic Performance of A Special Submarine Rescue System
, M.Sc. Thesis Sharif University of Technology ; Abbaspour, Madjid (Supervisor)
Abstract
The increasing growth of marine tourism has strengthened the activities related to this industry. One of the most profitable of these activities is recreational submarines. A traction recreational submarine is an idea in this field, in order to reduce costs, the propulsion force is removed and the submarine is towed by the mother ship. The most important reason for using the traction system and removing the independent drive is to prevent vibration and noise caused by the rotation of the propeller to prevent the escape of aquatic animals and to create a beautiful view from under the sea to watch underwater wonders. Searching for safety and saving people's lives in emergency situations is an...
Modeling and Control of Three-Phase Submerged Arc Furnaces for Performance Improvement
,
M.Sc. Thesis
Sharif University of Technology
;
Parniani, Mostafa
(Supervisor)
Abstract
Nowadays, submerged arc furnaces (SAFs) have gained considerable attention due to their lower energy consumption compared to electric arc furnaces. A submerged arc furnace typically consists of a shallow pot-shaped body made of a steel shell that withstands high temperatures and various chemical reactions. The steel casing enables the furnace to endure high temperatures and diverse chemical reactions. The required energy for the desired chemical reactions is supplied through three vertical carbon electrodes submerged under the arc within the charge materials. These electrodes are powered by three-phase alternating current from furnace transformer. The energy generated in the form of heat...
Teraffic Analysis with the Usage of Big Data Anlytics
, M.Sc. Thesis Sharif University of Technology ; Gholampour, Iman (Supervisor)
Abstract
Predicting traffic condition is one of the most important topics for traffic engineers and is a vital part of smart city. Extracting traffic behavior and realizing new traffic behaviors plays undeniable parts in big decision making of cities. On the other hand, progress of new technologies and devices for controlling and monitoring traffic caused the volume of traffic related data to grow exponentially. Velocity and variety of these data made normal data mining solution to fail in modeling and performing well. New data era has changed the view of large numbers of science and engineering majors. Traffic engineering also needs big data analytics for process of its own big data. Thus the need...
Exploring Public Perception of Justice in Mobility Transitions: Evidence from a Bicycle Sharing System in Iran
,
M.Sc. Thesis
Sharif University of Technology
;
Miremadi, Iman
(Supervisor)
Abstract
Globally, bicycle sharing is one of the fast-growing solutions to climate change in the transport sector. However, what inequities may be reflected, exacerbated, or arose from its adoption and use? Relying on a qualitative research design involving interviews with bicycle sharing users, non-adopters, and daily observers of the cycling infrastructure (N = 36), site visits, and a literature review, we examine distributive, procedural, and recognition injustices in association with Bdood, an operating BSS in Iran, a developing country that allows for less-documented types of injustice to arise. In doing so, we utilize a comprehensive transport/mobility justice framework, drawn from the fields...
Investigating the Impact of Digital Platforms on the Sustainable Development of Countries
, M.Sc. Thesis Sharif University of Technology ; Miremadi, Iman (Supervisor)
Abstract
The aim of this research is to examine the impact of digital platforms on the sustainable development of countries. This study employs a quantitative approach to determine the relationship between the development of digital platforms and sustainable development from economic and environmental perspectives. To achieve this, a composite index for the development of digital platforms is defined based on previous studies. Subsequently, data for its sub-indicators are collected from reliable international databases such as the World Bank, the International Telecommunication Union, and others, enabling the calculation of this index for 42 countries during the period 2014 to 2022. The results of...