Processing Queries with Mathematical Expressions on Encrypted Outsourced Databases

, M.Sc. Thesis Sharif University of Technology Naseri Boroujeni, Saeed (Author) ; Jalil, Rasool (Supervisor)

Abstract

The ever-increasing volume of data and the lack of computational and storage facilities have caused a managerial challenge to organizations. The existence of these challenges on the one hand and the increase of storage services on the other hand have compelled the organizations to delegate their storage and management of data to the server providers of cloud storage services. The outsourcing of data to servers obviates the need for purchasing exorbitant storage equipment and recruiting professional workforce in the organization. Since the organization’s data will be kept outside the organization’s ambience in case of using such services in form of outsourcing, and the data will not be under...

Development of a New Simulation Tool to Study the Asphaltene Precipitation and Deposition in Oil Well Column Based on Particle Scaling

, M.Sc. Thesis Sharif University of Technology Naseri Boroujeni, Saman (Author) ; Jamshidi, Saied (Supervisor) ; Taghikhani, Vahid (Supervisor)

Abstract

Formation, precipitation and deposition of heavy organic compounds of petroleum fluids including, but not limited to, asphaltene in oil reservoirs and production systems have been by far the most important and challenging flow assurance problems. Therefore, preventative actions to control organic deposits in oil formations and production systems which can lead inevitably to reduction or cessation in production, have always been a main challenge for oil producers.In this thesis, a one dimensional simulator have been developed to study asphaltene precipitation, aggregation and deposition in an oil well column at isothermal and non-isothermal conditions. While the previously proposed PC-SAFT...

Morphology-Dependent Electrocatalytic Activity of Silver Nanostructures and Differentia Pulse Voltammetry Determination of Atorvastatin at Silver Nanowires Modified Electrode

, M.Sc. Thesis Sharif University of Technology Naseri, Amene (Author) ; Shahrokhian, Saeed (Supervisor) ; Hormozi Nezhad, Mohammad Reza (Supervisor)

Abstract

In this work two shapes of silver nanostructures including silver nanowires and silver nanocubeswere synthesized by polyol method. Silver nanostructures were characterized by SEM, XRD and UV-Vis spectroscopy. Afterwards the morphology-dependent electrocatalyticperformance of these nanocrystals on the differential pulse behavior of naltrexone (NAL) was investigated. To this aim the differential pulse voltammetric behavior of NAL on a glassy carbon electrode modified with electrochemical deposited gold nanoparticles conjugated with different shapes of silver nanostructures and nafion was investigated. It was proved that silver nanowires show more effective electrocatalytic activity toward...

Parallel-plate waveguide integrated filters and lenses realized by metallic posts for terahertz applications

, Article International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz, 25 September 2016 through 30 September 2016 ; Volume 2016-November , 2016 ; 21622027 (ISSN) ; 9781467384858 (ISBN) Ahmadi Boroujeni, M ; Sharif University of Technology

IEEE Computer Society 2016

Abstract

In this paper, we report on the design and analysis of filters and lenses realized by an array of metallic posts integrated in a parallel-plate waveguide (PPWG). The design methodology of these components is inferred from the modal analysis of a spoof surface plasmonic waveguide composed of metallic posts arranged in a 1D periodic structure inside PPWG. Samples of the proposed devices are analyzed using a full-wave analysis method and their performance is assessed. We show that the mentioned structure can be used to realize all-metallic band-pass filters and lenses for mm-wave and terahertz applications

Photoresponse enhancing in nanostructured WO3films by slight change in heating ambient

, Article Journal of Alloys and Compounds ; Volume 693 , 2017 , Pages 871-875 ; 09258388 (ISSN) Naseri, N ; Sharif University of Technology

Elsevier Ltd 2017

Abstract

Providing solar hydrogen as a clean energy resource is one of the human challenges for future. Controlling oxygen vacancies as well as surface morphology in metal oxide semiconductors enables developing PEC H2production in some understood ways. Here, the influence of simple change in annealing atmosphere, air and pure oxygen, on photoresponse of nanocrystalline WO3has been studied completely. Results revealed that such slight change in annealing procedure increases effective surface interface and donor density by 77 and 72%, respectively. These effects and also retarding recombination of photogenerated electro-hole pair resulted in photocurrent enhancement under solar like illumination more...

Improved MPC algorithms for edit distance and ulam distance

, Article 31st ACM Symposium on Parallelism in Algorithms and Architectures, SPAA 2019, 22 June 2019 through 24 June 2019 ; 2019 , Pages 31-40 ; 9781450361842 (ISBN) Boroujeni, M ; Seddighin, S ; Sharif University of Technology

Association for Computing Machinery 2019

Abstract

Edit distance is one of the most fundamental problems in combinatorial optimization. Ulam distance is a special case of edit distance where no character is allowed to appear more than once in a string. Recent developments have been very fruitful for obtaining fast and parallel algorithms for both edit distance and Ulam distance. In this work, we present an almost optimal MPC algorithm for Ulam distance and improve MPC algorithms for edit distance. Our algorithm for Ulam distance is optimal in the sense that (1) the approximation factor of our algorithm is 1 + ϵ, (2) the round complexity of our algorithm is constant, (3) the total memory of our algorithm is almost linear (OH(n)), and (4)] the...

Haptic device application in persian calligraphy

, Article Proceedings - 2009 International Conference on Computer and Automation Engineering, ICCAE 2009, 8 March 2009 through 10 March 2009, Bangkok ; 2009 , Pages 160-164 ; 9780769535692 (ISBN) Mansouri Boroujeni, M ; Meghdari, A ; Sharif University of Technology

2009

Abstract

The Haptic device is capable of interacting dynamically with the operator by the forces it can exert on human's hand. Controlling the haptic device and constraining it through the desired trajectory is the common task in the most of the training systems. Haptic interface application in virtual Persian handwriting learning system is investigated in this paper. Two different modes of learning is investigated: The full guidance mode, guides the user to follow a prerecorded trajectory by applying proper force to operator's hand; whereas in partial guidance, combination of haptics andvisual feedback guides the operator and prevents deviation from the desired trajectory. © 2009 IEEE

Improving the efficiency and directivity of THz photoconductive antennas by using a defective photonic crystal substrate

, Article Optics Communications ; Volume 412 , April , 2018 , Pages 74-79 ; 00304018 (ISSN) Rahmati, E ; Ahmadi Boroujeni, M ; Sharif University of Technology

Elsevier B.V 2018

Abstract

One of the shortcomings of photoconductive (PC) antennas in terahertz (THz) generation is low effective radiated power in the desirable direction. In this paper, we propose a defective photonic crystal (DPC) substrate consisting of a customized 2D array of air holes drilled into a solid substrate in order to improve the radiation characteristics of THz PC antennas. The effect of the proposed structure on the performance of a conventional THz PC antenna has been examined from several aspects including radiation efficiency, directivity, and field distribution. By comparing the radiation performance of the THz antenna on the proposed DPC substrate to that of the conventional solid substrate, it...

Design of terahertz photoconductive antenna arrays based on defective photonic crystal substrates

, Article Optics and Laser Technology ; Volume 114 , 2019 , Pages 89-94 ; 00303992 (ISSN) Rahmati, E ; Ahmadi Boroujeni, M ; Sharif University of Technology

Elsevier Ltd 2019

Abstract

In this paper, arrays of two different terahertz (THz) antennas based on defective photonic crystal (DPC) substrates are proposed and their radiation characteristics are investigated by using full-wave simulation. We show that employing DPC substrates in THz photoconductive antenna (PCA) arrays reduces the amount of power coupled to the substrate surface waves and, as a result, decreases the mutual coupling between the elements of the antenna array and increases the directivity in the boresight direction. By studying 1 × 2 arrays of bowtie and four-leaf-clover-shaped antennas, we show that either the improvement of directivity in a broad bandwidth or the enhancement of photomixer antenna...

Performance Management of HSE Management System based on BSC Framework-the Case Study of Mapna Corporation

, M.Sc. Thesis Sharif University of Technology Naseri, Amin (Author) ; Sepehri, Mehran (Supervisor)

Abstract

A Balanced Scorecard (BSC) model is proposed to evaluate performance of Health, Safety and Environment (HSE) management systems. This model includes key performance indicators at three integrated levels. It has been tested and verified in a project-based organization in Iran, active in the area of power and energy. Results show that the company has done well in implementing HSE management processes, but no so well in growth and learning. This model may be used as a basis for comparing different companies and various proposed programs in the field of HSE management systems. The model includes indicators and sub-indicators in each category particularly related to stakeholders, processes, and...

Kinetic Modeling of Hydrocracking of Synthetic Wax from Fischer-Tropsch

, M.Sc. Thesis Sharif University of Technology Naseri, Fatemeh (Author) ; Khorasheh, Farhad (Supervisor)

Abstract

Fischer-Tropsch process (FT ) is one of the most important processes gas-to-liquid (GTL) conversion. This process converts synthesis gas into hydrocarbons. Depending on the catalyst and operating conditions of the process, heavy paraffins (Wax) are the most important products in this process. These products can be used to heavy paraffin catalyst hydrocracking in a process for the production of diesel fuel and gasoline to lighter products are suitable to be converted. The aim of this project is to develop a suitable kinetic model to describe the process of producing heavy paraffin hydrocracking process Fisher - Tropsch to be lighter products. In this regard, each 5 continuous mass model...

Modeling of the Biomechanical Properties of Articular Cartilage

, M.Sc. Thesis Sharif University of Technology Naseri, Hossein (Author) ; Firoozbakhsh, Keikhosrow (Supervisor)

Abstract

Articular cartilage Function is vital to joint tasks and its motion. The main biomechanical tasks of articular cartilage are a) the distribution of loads occurred in joints; b) providing joints with frictionless surface. The particular mechanical properties of articular cartilage make it possible for the Cartilage tissue to do its duty successfully. The biological factor that causes articular cartilage to damage is still unknown. It is believed that mechanical factors are the main reason for the cartilage destruction in osteoarthritis. Factors like age, heavy exercises and impact can begin tissue destructions and result in change in mechanical properties. To study the process of the...

Line Simplifcation Using the Hausdorff Distance as Error Metric

, M.Sc. Thesis Sharif University of Technology Naseri, Shahlla (Author) ; Zarei, Alireza (Supervisor)

Abstract

Due to recent advancements and wide usage of location detection devices, huge amount of data are collected by GPS and cellular technologies which exhibits moving objects trajectories. Using this information, it is possible to track a set of objects over a long period of time, as happens for instance in studying animal migration. Always, in these situations it is undesirable or even impossible (due to process and storage limits) to store the complete stream of positioning data. Then, simplifying a trajectory as a data reduction technique is the option for resolving such problems. Moreover, there is an increasing interest in queries capturing ”aggregate” behavior of trajectories as groups like...

Optimizing Co Nanoflakes Growth Parameters and Modifying Their Electro-catalytic Performance Using Carbon Nanostructures for Water Oxidation Reaction

, M.Sc. Thesis Sharif University of Technology Pourreza, Mohammad (Author) ; Naseri, Naimeh (Supervisor)

Abstract

Ease of solar hydrogen production using water splitting and its environmental benefits, distinct hydrogen from other energy carriers. Hydrogen is the most abundant material in the world that make up more than 90% of the world compounds. So applying this material as a clean fuel is the best way to prevent environmental problems caused by fossil fuels. For efficient hydrogen production from water, a suitable electrocatalyst with low overpotential, high mechanical strength and reasonable catalytic activity must be utilized. In this research, cobalt based electrocatalyst was used considering that electrodepositon conditions play an important role in its final efficiency. On the other hand,...

Synthesis, Characterization and Optical Study of a New Heterobinuclear Bis(Cyclometalated) Complex Containing Pt(II) and Au(I)

, M.Sc. Thesis Sharif University of Technology Naseri, Soroush (Author) ; Jamali, Sirous (Supervisor)

Abstract

The bis-cyclometalated platinum(II) complexes [Pt(ptpy)2], 3, and [Pt(fppy)2], 4, in which, ptpy = 2-(p-tolyl)pyridine and fppy = 2-(2,4-difluorophenyl)pyridine have been prepared. The reaction of 3 with one equiv [Au(PPh3)]+ (prepared from the reaction between AuCl(PPh3) and AgOTf) gave the heterobinuclear complex [Pt(ptpy)2Au(PPh3)].OTf, 5, by formation of a Pt→Au dative bond. The structure of all complexes were characterized using multinuclear NMR spectroscopy in solution phase and the structures of 4 and 5 determined using X-ray crystallography in solid state. The structure of heterobinuclear complex 5 shows an unusual Pt-Au bond that supported by Au-Cipso bond. The absorption and...

Evaluation and Optimization of Physical Properties of Graphene Oxide Nano Flakes to Confront Antibiotic Resistant Bacteria

, M.Sc. Thesis Sharif University of Technology Najafi, Fahimeh (Author) ; Naseri, Naimeh (Supervisor)

Abstract

Antibacterial resistance towards existing antibiotics has become a major problem in medicine and health in recent years. Therefor it has become a challenge for scientists in different fields to find new antibiotics. Graphene and its derivatives, specially Graphene Oxide has gained attention in this area due to their unique physical properties. Graphene Oxide is considered to be a promising 2D nanomaterial for biomedical applications, due to its ease of production, stability in water, unique chemical and mechanical properties and its biocompatibility compared to other nanomaterials. In this study, graphene Oxide was synthesized using modified Hummers’ method. In order to investigate the...

Modifying Hole Transport in Branched hematite Nanostructures for Photoelectrochemical Water Splitting

, M.Sc. Thesis Sharif University of Technology Farhoosh, Shima (Author) ; Naseri, Naimeh (Supervisor)

Abstract

Regarding increasing world population, air pollution and depletion of fossil fuels supplies, hydrogen production via photoelectrochemical water splitting is a promising approach for providing a clean and renewable source of energy. Hematite (α-Fe2O3), the most common natural form of iron oxide, with a suitable band gap, high stability, earth-abundant nature and low cost has been widely acknowledged as a photoanode. However, intrinsic drawbacks of hematite like low electrical conductivity, short hole diffusion length and high recombination rate of electron-hole pairs hinder its photoelectrochemical performance with high efficiency. In this research, hematite nanostructures were synthesized...

Studying Graphene Oxide Nanoflakes Size Effect on Antibiotic Resistant Bacteria

, M.Sc. Thesis Sharif University of Technology Homa, Kinza (Author) ; Naseri, Naimeh (Supervisor)

Abstract

Two-dimensional (2D) nanomaterials are ultrathin nanomaterials with a high degree of anisotropy and chemical functionality. Research on 2D nanomaterials is still in its infancy, with the majority of research focusing on elucidating unique material characteristics and few reports focusing on biomedical applications of 2D nanomaterials. Here we report the properties and application of 2Dnanomaterials in field of bio technology while used main material in our project is graphene oxide for investigating its antibacterial properties. Because the properties of graphene oxide (GO)-based materials strongly depend on the lateral size and size distribution of GO nanosheets; therefore, GO and its...

Measure for Macroscopic Quantumness via Quantum Coherence and Macroscopic Distinction

, M.Sc. Thesis Sharif University of Technology Naseri, Moein (Author) ; Raeisi, Sadegh (Supervisor)

Abstract

One of the most elusive problems in quantum mechanics is the transition between classical and quantum physics. This problem can be traced back to the Schrodinger's cat. A key element that lies at the center of this problem is the lack of a clear understanding and characterization of macroscopic quantum states. Our understanding of Macroscopic Quantumness relies on states such as the Greenberger-Horne-Zeilinger(GHZ) or the NOON state. Here we take a first principle approach to this problem. We start from coherence as the key quantity that captures the notion of quantumness and demand the quantumness to be collective and macroscopic. To this end, we introduce macroscopic coherence which is the...

Modifying TiO2 Photoanodes by Co-Pi Electrocatalyst for Solar H2 Production

, M.Sc. Thesis Sharif University of Technology Forouzandeh, Mojtaba (Author) ; Naseri, Naimeh (Supervisor)

Abstract

Currently, fossil fuels are the primary source of energy in the world. The increasing human need for energy and the limited resources of fossil fuels and their environmental side effects necessitate the search for other sources of energy. Considering its abundance and eco-compatibility, using solar energy is one of the best candidates for future. One of the methods to use solar energy is to convert and store it as hydrogen fuel by photoelectrochemical cells. In recent years, the main challenge with the production of hydrogen fuel in photoelectrochemical is optimizing them to increase efficiency. For this purpose, various approaches have been proposed such as the fabrication and use of...