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    Differentiating Signals Recorded from Rat Brain in Response to Different Olfactory Stimuli

    , M.Sc. Thesis Sharif University of Technology Arman Mehr, Matin (Author) ; Karbalaei Aghajan, Hamid (Supervisor)
    Abstract
    The olfactory sense in rats provides crucial information for identifying food sources, detecting threats, and facilitating social interactions. The olfactory bulb is one of the key brain regions involved in the initial processing of olfactory information and its transmission to higher brain areas for more complex processing. However, more advanced cognitive processes such as evaluation and decision-making rely on interactions between other brain regions. Among these, the striatum, as a part of the basal ganglia, plays a role in reward evaluation, reward-based learning, and shaping behaviors associated with sensory stimuli. This region contributes to learning, decision-making, and action... 

    Comparing half-metallic, MOKE, and thermoelectric behavior of the CrTiZ (Z = As, P) half-Heuslers: A DFT study

    , Article Materials Research Express ; Volume 8, Issue 4 , 2021 ; 20531591 (ISSN) Sadeghi, M ; Zelati, A ; Boochani, A ; Arman, A ; Mirzaei, S ; Sharif University of Technology
    IOP Publishing Ltd  2021
    Abstract
    Structural, half-metallic, magneto-optic, and thermoelectric properties of CrTiZ (Z = As, P) half-Heusleres compounds are investigated based on density functional theory. These compounds have mechanical stability in the ferromagnetic state with a high bulk modulus. They are often half-metallic with a large and integer magnetic moment and are very attractive in spintronics, magneto-optics applications. The magnetic moments of CrTiAs and CrTiP were 2.9865 μB and 3.00 μB, respectively, which were attributed to their ferromagnetic phase. Additionally, the positive sign of the phonon branches indicates the dynamic stability of these compounds. Applying both GGA and mBJ approximations, CrTiAs and... 

    The Effect of Rudder Angle on Ship’s Fuel Consumption

    , M.Sc. Thesis Sharif University of Technology Sadeghi Bughar, Babak (Author) ; Khorasanchi, Mahdi (Supervisor) ; Zare, Arman (Co-Supervisor)
    Abstract
    The aim of this research is to investigate the effect of speed and direction of current on ship fuel consumption. A KCS benchmark model has been numerically studied in calm water and fourteen current and wind conditions with the same speed and different directions to determine how the ship performance is dependent on flow conditions. The model has been simulated in an artificial basin propelled by a single right-handed propeller via a CFD commercial code. Numerical results revealed a linear relationship between the deviation of current and wind from head-sea or following-sea conditions and the rudder angle. The head-sea and following-sea currents and winds increased and decreased the lateral... 

    Evaluation of the topographical surface changes of silicon wafers after annealing and plasma cleaning

    , Article Silicon ; Volume 12, Issue 11 , 2020 , Pages 2563-2570 Stach, S ; Ţălu, Ş ; Dallaev, R ; Arman, A ; Sobola, D ; Salerno, M ; Sharif University of Technology
    Springer Science+Business Media B.V  2020
    Abstract
    Purpose: The morphological stability of silicon single crystal wafers was investigated, after performing cleaning surface treatments based on moderate temperature annealing and plasma sputtering. Methods: The wafer surfaces were measured by Tapping mode atomic force microscopy in air, before and after the different treatments. The 3D images were segmented by watershed algorithm identifying the local peaks, and the stereometric parameters were extracted thereof. The analysis of variance allowed to better assess the statistically significant differences. Results: All the resulting quantities were critically discussed. It appeared that the different cleaning treatments affected differently the... 

    The effect of thickness and film homogeneity on the optical and microstructures of the ZrO2 thin films prepared by electron beam evaporation method

    , Article Optical and Quantum Electronics ; Volume 53, Issue 8 , 2021 ; 03068919 (ISSN) Shakoury, R ; Talebani, N ; Zelati, A ; Ţălu, Ş ; Arman, A ; Mirzaei, S ; Jafari, A ; Sharif University of Technology
    Springer  2021
    Abstract
    In this study, ZrO2 coatings with different thicknesses were grown by the electron beam evaporation technique. The crystalline structure was studied by XRD analysis which suggested the tetragonal and monoclinic phases for ZrO2 coatings. Additionally, the film thickness slightly enhanced the crystallinity. The surface morphology and fractal features were analyzed using Scanning Electron Microscopy (SEM). The surface statistical parameters and the fractal geometry were employed to analyze the impact of the coating thickness and homogeneity on the morphology of the films. The statistical processing and fractal dimension revealed variations in the morphology parameters due to the electron beam... 

    Electrokinetic Flow in pH-Regulated Solid-State/Soft Micro-Nanochannels

    , Ph.D. Dissertation Sharif University of Technology Sadeghi, Morteza (Author) ; Saeedi, Mohammad Hassan (Supervisor) ; Mousavi, Ali (Co-Supervisor) ; Sadeghi, Arman (Co-Supervisor)
    Abstract
    In recent years, advances have been made in the field of miniaturization of the devices (in order to increase their efficiency, lessen the materials needed for the constructions and experiments, reduce costs and energy usage) resulting in the dramatic increase of surface to volume ratio in these devices. This progress has led to the dominance of surface forces which can be used to control very important interface phenomena having a special application such as electrokinetic. Using today’s manufacturing technology; it is possible to construct micro-nanochannels made from different materials such as silicon, glass, quartz, polydimethylsiloxane (PDMS), polymethyl methacrylate (PMMA) whose... 

    Deployment of multi-agent robotic systems in presence of obstacles

    , Article ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA2010, 12 July 2010 through 14 July 2010, Istanbul ; Volume 5 , 2010 , Pages 7-12 ; 9780791849194 (ISBN) Soltani, A ; Sayyaadi, H ; Sharif University of Technology
    2010
    Abstract
    The deployment of multi-agent systems in presence of obstacle deals with autonomous motion of agents toward a specified target by sensing each other and boundaries of obstacles. In this paper, asynchronous, scalable, distributed algorithm is used to deploy agents. Boundaries of obstacles are modeled by virtual agents. Algorithm was implemented by solving continuous n-median problem called generalized Fermat-Weber problem. It is shown that deployment is performed when position of real agents are the geometric median of their Voronoi cells. Simulation results show the validity of the proposed algorithm very well  

    Enforcing access control policies over data stored on untrusted server

    , Article 2017 14th International ISC (Iranian Society of Cryptology) Conference on Information Security and Cryptology, ISCISC 2017, 6 September 2017 through 7 September 2017 ; 2018 , Pages 54-57 ; 9781538665602 (ISBN) Soltani, N ; Jalili, R ; Sharif University of Technology
    2018
    Abstract
    One of the security issues in data outsourcing scenario is the enforcement of data owner's access control policies. This includes some challenges; namely, the number of keys required to access authorized resources, efficient policy updating, write access control enforcement, user and data owner overhead, and preserving confidentiality of data and policies. Most of the existing solutions address only some of the challenges, while they impose high overhead on both the data owner and users. Though, policy management in the Role-Based Access Control (RBAC) model is easier and more efficient due to the existence of role hierarchical structure and role inheritance; most of the existing solutions... 

    Experimental investigation of unsteady wake behind a section of a wind turbine blade

    , Article 25th AIAA Applied Aerodynamics Conference, 2007, Miami, FL, 25 June 2007 through 28 June 2007 ; Volume 2 , 2007 , Pages 870-876 ; 10485953 (ISSN) ; 1563478986 (ISBN); 9781563478987 (ISBN) Soltani, M.R ; Mahmoudi, M ; Sharif University of Technology
    2007
    Abstract
    A series of experiments were carried out to study the unsteady wake phenomenon behind an oscillating airfoil. The airfoil is a section of a wind turbine blade oscillating in pitch about the quarter chord axis at various reduced frequencies, oscillation amplitude and mean angles of attack. Streamwise velocity profiles were obtained by real time and instantaneous measurements at 35 vertically aligned points behind the airfoil via two similar rakes. One of rakes has only static pressure probes and the other is equipped with total pressure ones. An estimation of the variation of linear momentum defect during the oscillation is obtained and has been compared with the corresponding static one. The... 

    Water Quality Modeling of Urban Streams

    , M.Sc. Thesis Sharif University of Technology Soltani, Maryam (Author) ; Tajrishy, Masoud (Supervisor)
    Abstract
    With altering natural state and increasing impervious surfaces, traditional urbanization leads to deteriorating the environment and water catchments. During the years most efforts in order to control the urban runoff outflow, have been focused on quantity; and awareness about improving water quality has been raised just in the last few years and, which emphasizes on pollution source control. Standard water quality sampling methods are time consuming, expensive and because of sampling in broad geographic areas, difficult; however modeling is a more efficient way in assessing water quality and as worries about non-point source pollution grows, different kinds of models have been used to... 

    Structural Health Monitoring of composite Plates with Piezoelectric WaferActive Sensors

    , M.Sc. Thesis Sharif University of Technology Soltani, Zahra (Author) ; Abedian, Ali (Supervisor)
    Abstract
    Cost-effective and reliable damage detection is critical for utilization of composite materials. This research investigates a wavelet-based approach for SHM and detection of through-thickness crack in different lengths and angles in [0/45/-45/90]s CF/EP composite plate utilizing ANSYS finite element method (FEM) software and digital signal processing technique utilizing MATLAB software. To this end, a dual-PZT actuation scheme is applied, aimed at generating the S0 mode at a square composite plate. This study contributes to the damage detection by developing an improved wavelet-based signal processing technique that enhances the visibility and interpretation of the Lamb wave signals related... 

    Compressive Response of Cylindrical Concrete Columns Confined with Steel Spirals and GFRP Composites

    , M.Sc. Thesis Sharif University of Technology Soltani, Hesam (Author) ; Khalu, Alireza (Supervisor)
    Abstract
    Concrete structures require reinforcement and retrofitting because of possible mistakes in design or calculation, inconformity between plan and implementation, change in occupancy or applied loads, and decay. Development in technology, production of materials, and new methods play important roles in development of structure construction and reinforcement methods. Emerge of new materials creates great demand in studying, surveying, and determining design characteristic and criteria for these materials. One of these materials is FRP composite which is used in concrete structure reinforcement in different ways. In this laboratory research, the effect of external wrapping by GFRP composite... 

    Enforcing Access Control Policies over Data Stored on Untrusted Server

    , M.Sc. Thesis Sharif University of Technology Soltani, Naeimeh (Author) ; Jalili, Rasoul (Supervisor)
    Abstract
    Recently many organizations outsource their data to an external server due to easier data maintenance. One of the security issues in data outsourcing scenario is the enforcement of data owner’s access control policies. This includes some challenges; namely, the number of keys needed to access authorized resources, efficient policy updating, write access control enforcement, user and data owner overhead, and preserving confidentiality of data and policies . Most of the existing proposed solutions address only some of these challenges, while they impose high overhead on both the data owner and users. Moreover, most of them address enfrocement of policies in form of access control matrix and... 

    Synthesis, Characterization and Photocatalytic Application of ZnO/g- C3N4 Composite Nanorods Fabricated by Combined Sol Gel-Hydrothermal Methods

    , M.Sc. Thesis Sharif University of Technology Soltani, Mojtaba (Author) ; Moshfegh, Alireza (Supervisor)
    Abstract
    Because of the working conditions of semiconductors at ambient temperature and pressure, degradation of organic pollutants through semiconductors photocatalysis has attracted the interest of many researchers. Because of its large exciton binding energy,high chemical and physical stability,high electron and hole mobility, and low cost; zinc oxide, an n-type semiconductor with 3.2 eV direct band gap, is widely used in applications such as photocatalysts, solar cells, and light-emitting diodes. Among various morphologies of ZnO, 1D nanostructures such as nanowires and nanorods have recieved much attention due to their high surface to volume ratio. However, the application of ZnO as a... 

    A Protocol to Improve Privacy and Security of Anonymity Networks

    , M.Sc. Thesis Sharif University of Technology Soltani, Mahdi (Author) ; Jalili, Rasool (Supervisor)
    Abstract
    In recent two decades, different anonymous communication systems has been proposed. These systems are interested by journalists, bank employees, military forces, and human rights advocates. Tor is one of the most popular anonymous communication systems. Tor uses onion routing for privacy preserving. Re-cently, many attacks has been introduced against the anonymity of Tor users.In these attacks entry and exit nodes are compromised. One of these malicious nodes, makes the attack on the intented flow and the other one recognizes the flow. All these attacks admit their vulnerability against dummy messages. They state that, because of dynamics of onion’s keys, any dummy injection will dis-turb... 

    Design and Simulation (& Manufacturing) of A Micro-Gyroscope

    , M.Sc. Thesis Sharif University of Technology Soltani, Arman (Author) ; Akbari, Javad (Supervisor)
    Abstract
    Nowadays, microgyroscopes are among the most important products of MEMS. The production of small, precise and inexpensive gyroscopes has become possible as the result of recent developments in fabrication technology. In this thesis it is intended to introduce a new method for manufacturing more precise microgyroscopes regarding manufacture facilities. Using this new method, sensitivity and resistance of microgyroscopes are increased against noises which are primarily caused by vibration and rotation about undesirable axes. The rotational movement imposed on the gyro is detected through fluid flow within its torus channel. This transformation facilitates the measurement of the initial motion.... 

    Control Algorithm of Multi-agent Systems in Special Paths With an Applied Consideration in Biomechanical Engineering to Perform Operations of Interior Treatments

    , M.Sc. Thesis Sharif University of Technology Soltani, Ali (Author) ; Sayyadi, Hassan (Supervisor)
    Abstract
    In this project Deployment of multi-agent systems was studied. Maximum coverage over a point or curve or area is desired in deployment of multi-agent systems. A facility location optimization function was derived from geometrical concepts such as voronoi, n- geometric median and fermat-weber problem by optimization of which the deployment of multi-agent systems is performed. First, it is assumed that dynamic of agents is first order and second order .Next, it is assumed that agents are in a fluid. In all situations a suitable control algorithm was derived to optimize the facility location function to perform deployment. Next, another facility location function was derived by optimization... 

    Secure Transmission Strategies in Massive MIMO Systems in Presense of a Jammer

    , M.Sc. Thesis Sharif University of Technology Soltani, Marziyeh (Author) ; Mirmohseni, Mahtab (Supervisor)
    Abstract
    Massive MIMO systems are systems, where the base station has many number of antenna so each user’s channel is orthogonal to one another.These systems have some valuable advantages such as reduction of energy needed for transmission and significant improvement in spectral efficiency, which makes them be suitable for next generation of wireless communication systems. Another advantage of Massive MIMO systems is inherent resistance against passive eavsdroppers due to having a directed power radiation in direction of the desired user. However another physical layer attack threat these systems: attacking in pilot phase then eavsdropping in downlink phase which must taken care of in physical... 

    Dynamic Performance Enhancement of RC Slabs by Steel Fibers vs. Externally Bonded GFRP Sheets under Impact Loading

    , Ph.D. Dissertation Sharif University of Technology Soltani, Hesam (Author) ; Khaloo, Alireza (Supervisor)
    Abstract
    Recently, to improve the dynamic behavior of Reinforced Concrete (RC) slabs under impact load, the methods of externally bonding Glass Fiber Reinforced Polymer (GFRP) sheets to slab and internally reinforcing concrete by steel fibers have been proposed. Nevertheless, it is required to investigate the comparison between these two methods on response of RC slabs under impact loads. In this study, the influence of volume fraction of steel fibers, the number of GFRP sheet layers (one or two) and the arrangement of GFRP sheets (covering the whole or parts of surface), are examined. Performance of fourteen mm concrete slabs including one plain slab, one steel RC slab, three steel RC slabs... 

    Control of a Distributed Multi-agent System of Quadrotors for Transportation of a Shared Load

    , Ph.D. Dissertation Sharif University of Technology Soltani, Ali (Author) ; Sayyadi, Hassan (Supervisor)
    Abstract
    Nowadays, multi-agent robotic systems are implemented to perform various operations such as military mission, search and rescue operations, etc. One of the most interested robotic platforms for multi-agent systems is quadrotor aerial robot. In this paper, a team of quadrotors is prepared to perform a formation flight toward a specified target in order to catch and transport it on a desired path. Therefore, at first, trajectory tracking control of the quadrotor has been studied and two types of controllers have been introduced: Hierarchical controller and Non-hierarchical controller. Coordinate free structure of the hierarchical controller provides distinctive properties and guarantees...