Providing Confidentiality of Outsourced Data through Fragmentation

, M.Sc. Thesis Sharif University of Technology Dodangeh, Peyman (Author) ; Jalili, Rasool (Supervisor)

Abstract

Data outsourcing is considered as a promising approach in today computing and connected world. This approach enables organizations to outsource their data to anexternal third party server which is responsible for storing and propagation of outsourced data. Although data outsourcing offers many benefits, especially for those organizations with limited resources and increaseing data volume, but this approach in security aspects like providing confidentiality and privacy about curious external third party or other threats, is faced by serious challenges. In the recent decade many approaches for solving or at least decreasing the potential threats over providing confidentiality of outsourced...

A biometric security scheme for wireless body area networks

, Article Journal of Information Security and Applications ; Volume 41 , 2018 , Pages 62-74 ; 22142134 (ISSN) Dodangeh, P ; Jahangir, A. H ; Sharif University of Technology

Elsevier Ltd 2018

Abstract

Wireless body area networks (WBANs) are receiving significant interest as the next generation of wireless networks and emerging technology in the field of health monitoring. One of the most important factors for the acceptance of WBANs is the provision of appropriate security and access control mechanisms. Due to its nature in transferring the patients' sensitive data, WBAN has both classical and specific security requirements. In this paper, we survey such requirements and propose a new security scheme for satisfying them in WBANs. The proposed scheme deals with the overall network architecture, including intra- and inter-WBAN tiers, and proposes two mutual authentication and key exchange...

Effects of cold severe plastic deformation and heating on dendritic and non-dendritic structures: A356 alloy

, Article International Journal of Cast Metals Research ; Volume 27, Issue 5 , 1 October , 2014 , Pages 312-320 ; ISSN: 13640461 Dodangeh, A ; Kazeminezhad, M ; Aashuri, H ; Sharif University of Technology

2014

Abstract

In this research the effects of cold deformation and heating to the semi-solid temperature on microstructure and mechanical properties of cast dendritic and non-dendritic structures of A356 alloy were investigated. To produce the non-dendritic samples, the semi-solid slurry was obtained by electromagnetic stirring and rheoforged and then the samples were heated to semi-solid temperature. In order to impose the deformation to the dendritic and non-dendritic samples, multidirectional forging process was used. Non-dendritic samples were deformed with applying one to three passes of the multidirectional forging and then were kept at the semi-solid range of temperature again. Microstructural and...

A usage control based architecture for cloud environments

, Article Proceedings of the 2012 IEEE 26th International Parallel and Distributed Processing Symposium Workshops, IPDPSW 2012, 21 May 2012 through 25 May 2012 ; 2012 , Pages 1534-1539 ; 9780769546766 (ISBN) Tavizi, T ; Shajari, M ; Dodangeh, P ; Sharif University of Technology

2012

Abstract

Today modern computing systems leverage distributed models such as cloud, grid, etc. One of the obstacles of wide spreading these distributed computing models is security challenges which includes access control problem. These computing models because of providing features like on-demand self-service, ubiquitous network access, rapid elasticity and scalability, having dynamic infrastructure and offering measured service, need a powerful and continuous control over access and usage session. Usage control (UCON) model is emerged to cover some drawbacks of traditional access control models with features like attribute mutability and continuity of control. Several recent works have been done to...

Severe plastic deformation of rheoforged aluminum alloy A356

, Article Materials Science and Engineering A ; Volume 558 , 2012 , Pages 371-376 ; 09215093 (ISSN) Dodangeh, A ; Kazeminezhad, M ; Aashuri, H ; Sharif University of Technology

2012

Abstract

In this research, the electromagnetic stirring (EMS) process was used to produce semi-solid slurry with globular structure from cast A356 aluminum alloy. Then the slurry was forged in a die, which named rheoforging process. Utilizing multidirectional forging (MDF), the effect of severe plastic deformation on microstructure and mechanical properties of this alloy in dendritic and globular states was investigated. Shear punch, micro- and macro-hardness tests were used to study the mechanical properties of these samples. For metallographic examinations, the optical microscope equipped with the Clemex ® image analyzer software was used. Optimum globular structure of rheoforged specimens was...

Modeling of dislocation density and strength on rheoforged A356 alloy during multi-directional forging

, Article Computational Materials Science ; Vol. 81 , 2014 , pp. 284-289 Kavosi, J ; Saei, M ; Kazeminezhad, M ; Dodangeh, A ; Sharif University of Technology

2014

Abstract

In this study, a hybrid model is presented to predict the dislocation density and strength evolution of the rheoforged non-dendritic A356 alloy during multi-directional forging. Regarding the characteristics of non-dendritic A356 alloy, combination of Shear Lag and Nes models is used for the eutectic structure, and Nes model is used for the α-Al globular phase. The aspect ratio variations of Si particles in eutectic structure during 3 passes of multi-directional forging do not change the model predictions, significantly. Model predictions on shear stress are in good agreement with experimental results of shear punch test

Optimal Two-Phase Vaccine Allocation under Uncertain Impacts and Different Transition Rates

, M.Sc. Thesis Sharif University of Technology Dodangeh, Sana (Author) ; Najafi, Mehdi (Supervisor) ; Rafiee, Majid (Supervisor)

Abstract

Infectious diseases have always threatened the health of human beings. One of the most important causes of mortality in human societies is infectious diseases. The spread of these diseases in society, even if does not lead to death, can have devastating effects on society. Influenza is one of the infectious diseases that has attracted much attention today. It can be mild or severe and even cause hospitalization and death. Therefore, controlling and preventing the epidemic of this disease is very important. Epidemic models are commonly used to simulate the spread of infectious diseases. In this study to identify the influenza outbreak, a stochastic multigroup SEIR model with the migration...

Leaching kinetics of stibnite in sodium hydroxide solution

, Article International Journal of Engineering, Transactions B: Applications ; Volume 27, Issue 2 , February , 2014 , Pages 325-332 ; SSN: 10252495 Dodangeh, A ; Halali, M ; Hakim, M ; Bakhshandeh, M. R ; Sharif University of Technology

2014

Abstract

The leaching kinetics of stibnite in basic solution has been investigated. Spherical pellets of antimony sulphide were dissolved in 1 molar sodium hydroxide solutions at different temperatures. It was found that the shrinking core with ash layer model could satisfactorily explain the dissolution process. Using this model, it was found that initially the rate controlling step was a chemical reaction with activation energy of 10.2 kJ/mol. As the ash layer built up, diffusion through the ash layer became the rate controlling step. The activation energy for this step was found to be 33.4 kJ/mol. It was also observed that smaller particle size, larger solid to liquid ratio, and higher NaOH...

An Investigation into the Microstructure and Mechanical Properties of Rheoforged A356 Alloy After Severe Plastic Deformation

, M.Sc. Thesis Sharif University of Technology Dodangeh, Abbas (Author) ; Kazeminezhad, Mohsen (Supervisor) ; Aashuri, Hossein (Supervisor)

Abstract

Several studies are already on severe plastic deformation of wrought and cast aluminum alloys. Among these studies, no evidence of applying severe plastic deformation on the structure of rheocast or rheoforgedaluminum alloy can be found. So, in this research A356 alloy with globular structure was achieved using electromagnetic stirring and rheoforging. The optimum condition of globular structure with high sphericity was achievedafter holding the produced structure in semi-solid state for 10 min. Then, the effect of severe plastic deformation on mechanical and microstructural properties of this alloy and cast alloy was studied. The results show that with applying 3 passes of multidirectional...

High Saline Water Treatment by the Process of Membrane Distillation Combined with Solar Energy

, M.Sc. Thesis Sharif University of Technology Shokrollahi, Milad (Author) ; Rajabi, Abbas (Supervisor) ; Musavi, Abbas (Supervisor)

Abstract

In this study, membrane distillation process was used for treatment of high salinity waters. The focus of this study is to simulate and build a setup of membrane distillation process. Since the membrane distillation process is based on the driving force of the temperature difference, the required temperature is provided by both the use of heaters and the use of solar energy. To increase the feed temperature by solar energy, a black polymer coating on the main membrane is used. The main membrane used in this process is PVDF polymer and the polymer coated on the surface is the PAN polymer. After simulating and constructing the laboratory setup, the influence of a variety of parameters on the...

, M.Sc. Thesis Sharif University of Technology (Author) ; Akbarzadeh, Abbas (Supervisor)

Abstract

FGM sheets with component or grain size gradient in their thickness direction provide mechanical and physical gradient properties through ND direction. FGMs are fabricated by various methods including centrifugal casting, powder metallurgy, PVD and CVD,all of which suffer from some shortcomings such as porosity of the products, low rate and high cost of production and restrictions on mass production. In this study, 2 and 4 layered Al matrix FGM sheets containing SiC and Al2O3 powders were fabricated by laminating method of Accumulative Roll Bonding(ARB). Two approaches of stacking were chosen as accumulative coupled roll bonding (ACRB) and (ASRB) for initial roll bonding and subsequent...

Deposition of Ceramic Nanoparticles on Aluminum Sheet by Air Gun Spraying for ARB Processing of Nanocomposite Sheets

, M.Sc. Thesis Sharif University of Technology Keramat, Ehsan (Author) ; Akbarzadeh, Abbas (Supervisor)

Abstract

Particle reinforced aluminum matrix composites have considerable attraction in automotive and aerospace industries due to their special properties as light weight, high ratio of strength/density, improved elastic modulus, low coefficient of thermal expansion and high wear and corrosion resistance. Among the production processes of metal matrix composites, accumulative roll bonding process has particular importance due to producing ultrafine grained composite sheets. However, uncontrolled and undesired agglomeration of particles is the main problem in producing these composites. In this research, the Al2O3 and SiC nanoparticles were electrostatically stabilized against agglomeration by...

Make Policy for Optimizing Iran Gas Export

, M.Sc. Thesis Sharif University of Technology Alvandi, Mehdi (Author) ; Maleki, Abbas (Supervisor)

Abstract

This project examines four alternatives such as pipelines, oil injection wells, LNG & GTL in the purpose of Iran gas utilization. In this Project four strategies using cost/benefit analysis are examined. For this purpose, at first the cost of inlet feed gas per Mmbtu are calculated. Then regarding various scenarios of average world gas prices for the following thirty years, the cost & benefit of any way will be counted. Then with the use of energy security, the project will make energy policy. For this purpose, Shannon indicator will be used as one of the most reliable indicators. Due to the of use this indicator, the popular project will be chosen accordingly as a certain amount of gas the...

Diffusion of Lipid and Protein Molecules in Cell Membranes

, Ph.D. Dissertation Sharif University of Technology Khoshnood, Atefeh (Author) ; Jalali, Abbas (Supervisor)

Abstract

Lipid membranes are fundamental constituents of cell membranes and are now used in lap-on-a-chip technology. Membranes in living cells contain a significant fraction of proteins, which undergo lateral random movements due to thermal fluctuations and shear forces imposed by the solvent fluid. Prominent natural and biotechnological systems where membranes are highly sheared include the plasma membrane of endothelial cells, and membranes used in biosensors for high throughput screening of drug candidates, and in water purification devices. In these systems membrane is in direct contact with the mainstream suspension flow, which is driven by pressure gradients. The efficiency and function of...

Hot Workability of a Free-cutting Steel with Severe Sulfur Segregation During Continuous Casting

, M.Sc. Thesis Sharif University of Technology Naghdy, Soroosh (Author) ; Akbarzadeh, Abbas (Supervisor)

Abstract

Splitting in ingot cast structures and transverse cracks in continuous cast structures are the main problems of hot rolling of low carbon resulfurized free-cutting (LCRF) steels. Presence of high volume fraction of manganese sulfide inclusions in cast structure increases the risk of alligatoring in hot rolling. Because of high sulfur content of these steels and probability of formation of low melting point phases, minimum level of manganese and maximum level of copper and tin is necessary. Morphology of manganese sulfide is another important factor in hot forming of these steels, which can be controlled by level of deoxidation in steel making. In fact, MnS2 is present in fully killed...

(Assessing the Role of Carbon Capture and Storage Technology on Iran’s Oncoming Energy System(Technology Deployment Policy Making

, M.Sc. Thesis Sharif University of Technology Banan, Zoya (Author) ; Maleki, Abbas (Supervisor)

Abstract

Based on International Energy Agency studies, achievement of 450 ppm CO2-equivalent emission target in global emission means that the CO2 emissions in 2050 must be reduced to %50 of 2005 level, and this implies that a portfolio of emission reduction policies and strategies need to be exploited through current century.
At the present time, Carbon Capture and Storage (CCS) Technology is a dominant strategy among all the long-term carbon abatement strategies in many countries. Nevertheless, its potential as a climate mitigating option will be proved, only if it is implemented in the countries which are developing at a great pace and taking advantage of fossil fuels in order to afford their...

Development of an Analytical Framework for Evaluation of Climate Change Mitigation Policies on Iran’s Energy Security

, M.Sc. Thesis Sharif University of Technology Eshraghi, Hadi (Author) ; Maleki, Abbas (Supervisor)

Abstract

Climate change and energy security are key drivers for future energy policy. While energy security has been a pillar of energy policy for about a century, concern about climate change is more recent and is bound to radically change the landscape of energy policy. Policy makers are now under increasing pressure to address these twin challenges: to develop cost-effective policies that will both ensure the security of our energy system and reduce greenhouse gas emissions.
Main Effort in this Project is to construct an integrated model of Iran’s energy system to serve as a policy analysis tool, by which policymakers are able to identify the future effects of a wide range of policies in...

Evaluation the Effect of Thermo-Mechanical Parameters on Microstructure and Texture of Electrical Steel for Improving Magnetic Permeability

, M.Sc. Thesis Sharif University of Technology Ahmadian, Peyman (Author) ; Akbarzadeh, Abbas (Supervisor)

Abstract

Dependence of some magnetic properties such as core loss and permeability on temper rolling was studied in this thesis. It is shown that with a proper temper rolling sharper textures are obtained in the electrical steel and the magnetic properties in the longitudinal and traverse directions are improved. By texture analysis, it is shown that because of temper rolling, shear strain on the surface of the sheet is the main factor for abnormal grain growth and shear texture formation on the surface. The result of formation of this texture is enhancement of the {100} intensity and reduction of the {111} intensity, leading to the improvement of the permeability. Temper rolling is always...

Risk Management for DG Owners

, M.Sc. Thesis Sharif University of Technology Karimi, Ahmad (Author) ; Rajabi, Abbas (Supervisor)

Abstract

Distributed generation (DG) and its utilization have some benefits and risks for its owner and power network. From owner perspective, benefits of DG include selling energy, reducing costs related to fuel, and other economic benefits. However, there are some risk factors for the owner including risk of supplying fuel, risk of selling generated power, and other risk factors related to establishment of the DG unit. Utilizing risk-reduction tools such as signing agreements for selling power, purchasing fuel, and related economic tools are necessary for risk management of the owners of DG units. The purpose of this thesis is to investigate the economic situation of the DG units and optimize the...

Exception Fault Localization in Smart Mobile Applications

, M.Sc. Thesis Sharif University of Technology Mirzaei, Hamed (Author) ; Heydarnoori, Abbas (Supervisor)

Abstract

In software programs, most of the time, there is a chance of error, even though they are tested carefully. Finding error-related pieces of code is one of the most complicated tasks and it can make incorrect results if done manually. Semi-automated and fully-automated methods have been introduced to overcome this issue. The rapid growth of developing smart mobile applications (SMAs) in recent years, competition among the development teams and many other factors have increased the chance of errors and hence, the quality of these applications have reduced. There are two approaches to test SMAs in order to reach a high degree of quality: (1) using existing traditional methods and adapting them...