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hassani--morteza
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Android App Permission Analysis Based on Developer’s Privacy Policies
, M.Sc. Thesis Sharif University of Technology ; Amini, Morteza (Supervisor)
Abstract
With the increasing use of mobile smartphones, securing the information and protecting the mobile users’ privacy is one of the important subjects in this context. Android, as one of the most popular operating systems for smartphones, uses strategies to provide system security and user privacy; one of these strategies is permission system. Applications should get permissions from users to access their sensitive data. Most related researches and the android itself, focuses on granting or revoking permissions to the program in a way that it doesn’t misuse the user’s sensitive data, but most of the time, the purpose of accessing data is not obvious and the user doesn’t have enough knowledge...
Seismic Analysis of Multi-Degree Freedom Structures Equipped with Telescopic Metallic Yield Dampers (TLYD)
, M.Sc. Thesis Sharif University of Technology ; Eskandari, Morteza (Supervisor)
Abstract
Ordinary structures absorb a large amount of input energy by structural elements whereas failure in these elements causes a huge loss in structure and it’s really difficult to repair or unrepairable. Nowadays a wide range of metallic dampers is used in structures as fuse elements. this research evaluates the response of structures that are equipped with a novel steel damper named Telescopic Lead Yield Damper (TLYD) which was introduced by Eskandari in 2018. As TLYD has a different yielding plateau it can tolerate large deformations. In this research firstly this novel damper was introduced and the performance of the damper under cyclic loading was demonstrated. Then a numerical model of 6,...
Performance Improvement of Android Repackaged Applications
, M.Sc. Thesis Sharif University of Technology ; Amini, Morteza (Supervisor)
Abstract
Attacks on Android devices often take the form of repackaging. Attackers change a well-known app that has been downloaded from the app store, reverse engineer it, add some malicious payloads, and then upload the modified app to the app store. Because it is difficult for users to distinguish between the changed app and the original app, users can be easily duped. The malicious code inside the modified apps can launch attacks after they are installed, typically in the background. There are so many repackage detection method proposed during last years of researches in this area. developing an approach to detect android repackaged application should contains two main goal, speed and accuracy of...
Deep Learning and Optimal Control
, M.Sc. Thesis Sharif University of Technology ; Fotouhi, Morteza (Supervisor)
Abstract
Our main focus in this thesis is on optimal control methods for the analysis of deep neural networks, such as the supervised learning problem. A neural network with a large number of layers can be modeled with an ordinary differential equation, whose control parameters play the role of intermediary functions in the neural network. This model gives us a more powerful tool to analyze the asymptotic behavior of the neural network. Also, in this thesis, the problems of numerical implementation of these methods will be discussed
Mathematical Modeling and Simulation of Tumor Angiogenesis
, M.Sc. Thesis Sharif University of Technology ; Fotouhi, Morteza (Supervisor)
Abstract
A major medical revolution that is helping us overcome some of the worst diseases, including cancer, is angiogenesis, which is based on the processes our bodies use to develop blood vessels. Most human cancers have acquired six essential capabilities: self-sufficiency in growth signals, insensitivity to growth-inhibitory signals, programmed cell death escape, unlimited replication potential, persistent angiogenesis, and tissue invasion that can induce metastasis. In other words, the defense mechanism that prevents any of these acquired capabilities must be neutralized before the cells become malignant and invasive tumors. In fact, tumors in the non-vascular growth stage can only grow up to...
Preserving Privacy Through Intelligent Generation of Fake Events in Smart Homes
, M.Sc. Thesis Sharif University of Technology ; Amini, Morteza (Supervisor)
Abstract
Recently, the use of the Internet of Things (IoT) to enhance various environments has gained significant attention. With this technology's expansion into the realm of smart homes, IoT platforms have received considerable interest. These platforms help users implement automation rules by connecting a variety of smart devices and service providers. However, these platforms also have access to users' sensitive data, which could lead to privacy violations; this is because the data sent to the platform could be exploited by an attacker to extract patterns of user behavior. Current IoT platforms lack adequate measures to preserve user privacy, and furthermore, these platforms are not universally...
Impedance analysis of growth and morphology of electropolymerized polypyrrole nanocomposites [electronic resource]
, Article Journal of New Materials for Electrochemical Systems ; 2014, Volume 17, Number 2 ; Sadrnezhaad, S. K ; Sharif University of Technology
Abstract
Pure polypyrrole (PPy), PPy/Al2O3 and PPy/SiO2 nanocomposites synthesized galvanostatically using different polymerization charges. Electrochemical impedance measurements of pure polypyrrole revealed that the film thickness affected the impedance responses. The characteristic frequencies vs. film thickness that obtained using Cole-Cole plots showed that electrodeposition mechanism changed from 3D to 1D after nuclei overlapping for pure PPy. Analysis of the nanocomposites impedance spectrums revealed no changes during the film growth, i.e. deposition continues 3D even after nuclei overlapping. Scanning electron microscopy (SEM) confirmed the impedance results and showed that the morphology of...
Effect of Grinding and Shot Peening on Fatigue Life of Welded Joints
, M.Sc. Thesis Sharif University of Technology ; Farrahi, Gholamhossein (Supervisor)
Abstract
Metallurgical initial defects, stress concentration due to change in geometry and induced tensile residual stress during welding create an extraordinary high possibility of fatigue cracks nucleation and propagation in the weld toe region. Despite this, the ever increasing use of welding in offshore, aerospace and automotive industries, as the most applied mechanical joint, has occasioned a very extensive attempt to achieve an in-depth understanding of failure mechanisms and fatigue life improvement techniques of welded joints. Generally, these techniques could be classified into two broad categories. The first consists of methods that modify the geometry and the other is related to the...
Enhancing Umbrella Activities in Agile Methodologies
, M.Sc. Thesis Sharif University of Technology ; Ramsin, Raman (Supervisor)
Abstract
The adaptive nature of agile processes and their conformance to the turbulent nature of business and organizational environments has been greeted with enthusiasm by both project and stakeholder communities. Through deviating from conventional linear and plan-driven frameworks, Agility aims at accommodating the dynamicity of its target environment at the process level during the project lifecycle. This deviation from standard frameworks confronts process management and project framework activities with key challenges. While existing frameworks and standards provide adequate support for linear process management, the agile approach lacks a coherent framework that defines and outlines process...
Design of Optimum Railroad Alignments Using Ant Colony Optimization
,
M.Sc. Thesis
Sharif University of Technology
;
Shafahi, Yousef
(Supervisor)
Abstract
Optimum railroad alignment, which can be categorized into continuous problems, has been a conundrum for engineers because of two reasons: At the first, there is a wide variety of information that is necessary for finding optimum one. Secondly, the major costs of a railway, such as length-dependent, traffic-dependent, volume-dependent and location-dependent are affected by the numerous factors so that, it may be difficult to formulate them. In order to solve large scale continuous optimization problems, there are two approaches: firstly, such problems may be tackled with a combinatorial optimization algorithm, e.g. ant colony optimization (ACO), by the continuous range of allowed values are...
Investigating and Explaining Dr. Golshani’s Points of View about Religious Science
, M.Sc. Thesis Sharif University of Technology ; Hassani, Hamid Reza (Supervisor)
Abstract
Entrance of secular science to Muslim societies has made them face a duality. That is because, on the one hand, they like to preserve their religious values; and on the other, prevalence of secular ideas prevents people from being committed to such values. Therefore, some Islamic scholars proposed religious science as opposed to Western secular science as a remedy to this crisis In case of religious science, explanatory model has the highest position, but disagreement over how to combine experimental and religious characteristics has led to different models in this area. One of the explanatory models of religious knowledge is that of Doctor Mehdi Golshani which has received due attention at...
Electronic Word of Mouth: Consumers' Motives for Participation in Online forums
,
M.Sc. Thesis
Sharif University of Technology
;
Modarres, Abdolhamid
(Supervisor)
Abstract
Consumers Communicate with each other to share information and feelings about products and brands. One important area to study personal influence in contemporary environment is online personal influence or electronic word of mouth. This study develops and tests consumers' motivations to participate in eWoM communication in online discussion forums. The main reason to choose Online forums is the huge number of eWoM discussions which occur in them. The main goal of this study is developing an aggregate framework for consumers' motives for opinion giving and seeking in online forums.To accomplish this goal we studied a comprehensive literature review, identified all motivations for WoM and...
Course Scheduling Problem in Sharif University of Technology
, M.Sc. Thesis Sharif University of Technology ; Salmasi, Naser (Supervisor)
Abstract
This study strives to solve the course scheduling problem based on the constraints in Sharif University. In course scheduling problem, first we need to assign each course to a professor (This is done according to professors’ preferences in Sharif University) then we assign each course to a classroom and a time slot subject to professors, classrooms and time constraints (For example no two courses can be assigned to the same classroom at the same time slot). If solved manually, the solving process will take several days and at best results in a feasible solution. The education department is responsible for scheduling 661courses in five days a week and assigning them to 56 classrooms...
Investigation the Effect of Content and Plastisity of Plastic Fines on Liquefaction Resistance of Sand Using Cyclic Simple Shear Tests
, M.Sc. Thesis Sharif University of Technology ; Ahmadi, Mohammad Mehdi (Supervisor)
Abstract
Regarding the existing contrary in the literature in relation to the effect of plastic fine on sand liquefaction behaviour, we decided to study this effect. Amounts of 5, 15, and 25 percent of two types of plastic fine, Kaolinite with PI=19 and Bentonite with PI=116 added to Firoozkooh Sand and 68 stress controlled tests were conducted using cyclic simple shear apparatus. In all teste the frequency of shear loading and consolidating vertical effective stress were constant and 0.1 Ht and 100 kPa respectively. Reaching excess pore water pressure ratio to the maximum value (r_u=Max) and reaching double amplitude shear strain to the value of 5% have been considered as liquefaction critera. In...
Modeling the Hysteresis Characteristic of Power Transformer Core for the Assessment of Inrush Current and Providing a Method to Reduce this Current
, M.Sc. Thesis Sharif University of Technology ; Vakilian, Mehdi (Supervisor)
Abstract
Inrush current as an inherent phenomena in transformer energizing cause to dramatic increase in current which flow through windings of transformer in first periods of energizing. first peak of inrush current can exceed even to several orders of nominal current but it decrease with time and at last after damping process it reaches to nominal currents. In large transformer this time can exceed to several minutes and cause damage to winding insulation, mechanical defects, wrong response of protection system and interrupting loads. Magnitude of this current has a close relation with residual flux. In this thesis a method for calculation of inrush current in single phase and three phase...
Solve the Project Scheduling Problem Considering the Assumed Discount in Buying Cost Function for Nonrenewable and Perishable Resources
, M.Sc. Thesis Sharif University of Technology ; Shadrokh, Shahram (Supervisor)
Abstract
Project Scheduling is one of the most important branches of operations research and management science. In this paper, project scheduling problem with a deterministic duration of activities is studied. Resources are considered nonrenewable ones which are perishable. First of all, the project scheduling problem has been studied with a rate of corruption of inventory. Then, a rate of corruption with three parameters for Weibull is considered. Cost function for purchasing a renewable Perishable resource, has been assumed that has growing discounts for the purchase of certain health differently. Project costs are included purchase costs and maintenance costs. The objective function is the...
Study and Performance Evaluation of Nonlinear Compensation Methods in Coherent Optical OFDM Systems
, M.Sc. Thesis Sharif University of Technology ; Salehi, Javad (Supervisor)
Abstract
In this thesis, we model and analyze coherent optical OFDM systems which are highly concerned as future fiber optic communication. To this end, we first introduce various applications of that in optical communication systems and investigate its probes and cones. In the rest of the thesis, we characterize the mathematical structure of the nonlinear phase noise and discuss the previous methods of compensation of that and propose some new ways of nonlinear phase noise compensation and equalization. And as we discuss each method we also investigate its computational complexity and BER performance. We propose three new phase noise compensation method, considering optical phase conjugation, we...
Evaluation of Effect of Phreatic Line Level on Stability of Uupstream Tailings Dams
, M.Sc. Thesis Sharif University of Technology ; Pak, Ali (Supervisor)
Abstract
Tailings dams are considered as one of the most important geotechnical structures and due to the large amount of contaminated tailings deposited behind the dam, any failure of these structures, apart from loss of lives and properties, can be an environmental disaster. Researches show that most of the failure incidents in the last few decades have happened in tailings dams constructed using upstream method. As a result, it is of great significance to study the stability of upstream tailings dams.
The place of the phreatic line in the dam body plays a critical role in stability of tailings dams. Soil-atmosphere interaction effects such as precipitation, runoff, interception, infiltration,...
The place of the phreatic line in the dam body plays a critical role in stability of tailings dams. Soil-atmosphere interaction effects such as precipitation, runoff, interception, infiltration,...
PVDF/SiO2 Nanocomposite Coating with Different Wettability in Contact with Oil and Water for phase Separation Propose
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
increased cohesion up to 4H pencil. Results of immersion test in water showed stability of coatings. Polarization test in naphtha and water mixture for stainless steel, copper and aluminum meshes demonstrated 98.89%, 86.25% and 66.6% protection efficiency respectively. In order to study of oil and water separation efficiency, mixtures of water and naphtha with different content of naphtha were used. Separation test for 200μm St.St mesh in different slopes demonstrated that changing of slop increase separation efficiency up to 95.5% for water and up to 100% for naphtha. Separation test for meshes with different pore size demonstrated that meshes with small pore size are more appropriate for...
Lensing as a probe of early universe: From CMB to galaxies
, Article Journal of Cosmology and Astroparticle Physics ; Volume 2016, Issue 5 , 2016 ; 14757516 (ISSN) ; Baghram, S ; Firouzjahi, H ; Sharif University of Technology
Institute of Physics Publishing
2016
Abstract
The Cosmic Microwave Background (CMB) radiation lensing is a promising tool to study the physics of early universe. In this work we probe the imprints of deviations from isotropy and scale invariance of primordial curvature perturbation power spectrum on CMB lensing potential and convergence. Specifically, we consider a scale-dependent hemispherical asymmetry in primordial power spectrum. We show that the CMB lensing potential and convergence and also the cross-correlation of the CMB lensing and late time galaxy convergence can probe the amplitude and the scale dependence of the dipole modulation. As another example, we consider a primordial power spectrum with local feature. We show that...