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    Study on Very High Energy Cosmic Ray at Tehran Surface

    , Ph.D. Dissertation Sharif University of Technology Sheidaei, Farzaneh (Author) ; Samimi, Jalal (Supervisor)
    Abstract
    The cosmic ray astronomy was born in 1937 when Victor Hess flied with his balloon to the height of 17,500 feet. He found that the cosmic rays come from out of atmosphere. There are three fundamental questions from that time. The goal of all cosmic ray's experimental activities and related theories is finding out the answer of these questions. The first question is about the energy and composition spectrum of cosmic rays. The second one is finding the sources which can product the very high energy particles such as the protons with the energy of 1021eV found in some observatory such as AGASA and Haverah Park. The last question is the process of diffusion of cosmic rays in the galaxy. One of... 

    Moon shadow on high energy cosmic ray in data of a small extensive air shower array

    , Article Astroparticle Physics ; Volume 33, Issue 5-6 , 2010 , Pages 330-334 ; 09276505 (ISSN) Sheidaei, F ; Bahmanabadi, M ; Samimi, J ; Sharif University of Technology
    2010
    Abstract
    Data from a small air shower array were used to examine the cosmic ray shadow of the Moon at energies more than 100 TeV. A simple technique has been used for the analysis of this data. In this technique the number of EAS events with arrival directions falling in error circles centered about the moving moon is compared to the mean number of events falling in error circles with centers randomly chosen in the sky. For any assumed angular radius of the error circle the deficit in EAS event count in the direction of moon which is a moon-related effect is interpreted as the shadow of the moon. A simple theoretical model has been developed to relate the mean number of EAS events, Nsky, to the... 

    Experimental studies of positive and negative atmospheric muons with a cosmic rays telescope

    , Article Astroparticle Physics ; Volume 24, Issue 3 , 2005 , Pages 183-190 ; 09276505 (ISSN) Bahmanabadi, M ; Khakian Ghomi, M ; Sheidaei, F ; Sharif University of Technology
    2005
    Abstract
    An experiment has been developed for the measurement of the muon charge ratio (ratio of positive to negative muons) in the cosmic ray flux in energy range 0.236-0.242 GeV. The muon charge ratio is found to be 1.35 ± 0.10 with a mean zenith angle of 32° ± 5°. Meanwhile, the distributions of muons in zenith (θ) and azimuth angles have been studied. A cosnθ distribution with n = 1.95 ± 0.13 has been obtained. An asymmetry has been observed in East-West directions because of geomagnetic field. © 2005 Elsevier B.V. All rights reserved  

    Instrumentation development for an array of water cherenkov detectors for extensive air shower experiments

    , Article Journal of Physics G: Nuclear and Particle Physics ; Volume 36, Issue 11 , 2009 ; 09543899 (ISSN) Sheidaei, F ; Bahmanabadi, M ; Keivani, A ; Samimi, J ; Sharif University of Technology
    2009
    Abstract
    A new small array of Cherenkov detectors has been deployed in Tehran, 1200 m above sea level. This array contains four tanks of distilled water with a diameter of 64 cm and a height of 130 cm. The effective area of each tank is about 1382 cm2. They are used to detect air showers and to record the arrival time of the secondary particles. We have collected about 640 000 extensive air showers (EAS) in 8298 h of observation time from November 2006 to October 2007. The distribution of air showers in zenith and azimuth angles has been studied and a cosn distribution with n = 6.02 0.01 was obtained for the zenith angle distribution. An asymmetry has been observed in the azimuthal distribution of... 

    A new approach for closed-form analytical solution of two-dimensional symmetric double contacts and the comparison with finite element method

    , Article Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology ; Volume 232, Issue 8 , 2018 , Pages 1025-1035 ; 13506501 (ISSN) Ghanati, P ; Adibnazari, S ; Alrefai, M ; Sheidaei, A ; Sharif University of Technology
    SAGE Publications Ltd  2018
    Abstract
    In this paper, a new procedure is developed for the solution of a general two-dimensional uncoupled symmetric double contact problem with smooth contact zones in which the indenter geometry is described by a piecewise biquadratic function. This procedure gives an approximate closed-form solution for any smooth indenter profile. In order to evaluate the accuracy of this approach, it is applied to the symmetric indentation of a flat surface by two rigidly interconnected parabolic indenters and results are compared with the exact unclosed-form solution. Moreover, this procedure is applied to the symmetric indentation of a flat surface by two rigidly interconnected cylinders to compare the... 

    Galactic anisotropy of cosmic ray intensity observed by an air shower experiment

    , Article Publications of the Astronomical Society of Australia ; Volume 23, Issue 3 , 2006 , Pages 129-134 ; 13233580 (ISSN) Bahmanabadi, M ; Khakian Ghomi, M ; Sheidaei, F ; Samimi, J ; Sharif University of Technology
    2006
    Abstract
    We have monitored multi-TeV cosmic rays by a small air shower array in Tehran (35°43′ N, 51°20′ E, 1200 m ≤ 890 g cm -2). More than 1.1 × 106 extensive air shower events were recorded. These observations enabled us to analyse sidereal variation of the galactic cosmic ray intensity. The observed sidereal daily variation is compared to the expected variation which includes the Compton-Getting effect due to the motion of the earth in the Galaxy. In addition to the Compton-Getting effect, an anisotropy has been observed which is due to a unidirectional anisotropy of cosmic ray flow along the Galactic arms  

    Evaluation of the optimal performance of passenger vehicle by integrated energy-environment-economic modeling

    , Article International Journal of Environmental Science and Technology ; Volume 4, Issue 2 , 2007 , Pages 189-196 ; 17351472 (ISSN) Farzaneh, H ; Saboohi, Y ; Sharif University of Technology
    CEERS  2007
    Abstract
    Analysis of multi dimensional interactions of flow of energy in passenger vehicle is a complex task that necessitates development and utilization of analytical tools. Development of analytical tools with high complexity is usually based on conclusions of many concepts and theories from different scientific disciplines. In this approach, Passenger vehicle is supposed to be organized in the form of a firm and appears in the market that oriented towards establishing an effective energy supply system which may be identified as delivering the product (person kilometer or tone kilometer) with minimum operation costs. To this end, an optimization model named power software founded on theory of firm... 

    Model for analysis of energy flow from tank-to-wheel in a passenger vehicle

    , Article 2005 IEEE Vehicle Power and Propulsion Conference, VPPC, Chicago, IL, 7 September 2005 through 9 September 2005 ; Volume 2005 , 2005 , Pages 150-153 ; 0780392809 (ISBN); 9780780392809 (ISBN) Farzaneh, H ; Saboohi, Y ; Sharif University of Technology
    2005
    Abstract
    Analysis of multi dimensional interactions of flow of energy in passenger vehicle is a complex task that necessitates development and utilization of analytical tools. Development of analytical tools with high complexity is usually based on conclusions of many concepts and theories from different scientific disciplines. In this approach, Passenger vehicle is supposed to be organized in the form of a firm and appears in the market that oriented towards establishing an effective energy supply system which may be identified as delivering the product (person per mileage removable) with minimum operation costs. To this end, an optimization model named POWER software founded on theory of firm of... 

    Software of passenger vehicle optimal work and energy recovery (POWER)

    , Article 12th International Conference on Urban Transport and the Environment in the 21st Century, URBAN TRANSPORT 2006, UT06, Prague, 12 July 2006 through 14 July 2006 ; Volume 89 , 2006 , Pages 691-699 ; 17433509 (ISSN); 1845641795 (ISBN); 9781845641795 (ISBN) Farzaneh, H ; Saboohi, Y ; Sharif University of Technology
    2006
    Abstract
    In our investigation, the model of optimal energy flow in a passenger vehicle has been founded on the theory of firm microeconomics. Based on this theory, the car owner tries to minimize the total cost of the system (including the cost of time of the traveller) subject to the satisfaction of the required transport services and technological, economical, environmental and institutional constraints. The aforementioned model has been developed using a technique of mathematical programming. The model depicts the behaviour of a nonlinear system and it includes many nonlinear functions in the objective function and in the constraints. Solving the large nonlinear set of constraints and identifying... 

    Radiowave Propagation Modeling Along a Street for Use in Microcells in Third Generation Wireless Communications

    , M.Sc. Thesis Sharif University of Technology Sadeghi, Hamed (Author) ; Farzaneh, Forouhar (Supervisor)
    Abstract
    In this thesis, a simplified method was introduced to model the wave scattering by the metallic objects in a microcell, in order to determine the coverage pattern. First, the equivalent images method was introduced, which models the building walls effect. This method is fast, memory saving and accurate enough to estimate the scattered fields. Two-ray incidence model accuracy was investigated and confirmed in modeling the scattering from the metallic objects. This method also enhances saving in time and memory. The accuracy of single scattering assumption was investigated and confirmed in a scenario of multiple metallic scatterers. Based on this assumption, we can superimpose the scattered... 

    Design and Simulation of Smart Patch Antenna Array in 2.4 GHz band

    , M.Sc. Thesis Sharif University of Technology Hosseini, Mahdi (Author) ; Farzaneh, Forouhar (Supervisor)
    Abstract
    Over the past few years , demand for wireless communication services have grown at a formidable rate. As such we need to find new ways to support more and more wireless users in a confined space. this means that the capacity of networks should be significantly increased to overcome formidable rate of subscribers growth. That is why the smart antennas have become very popular in communication systems. Smart antennas are a kind of adaptive antenna arrays with smart signal processing algorithms used to find direction of arrival(DOA) of the signal, and use it to calculate suitable weights to direct the antenna beam on the desired user and nulling interferences. In this thesis, DOA estimation... 

    Evaluation of Phase Comparison DOA Estimation Methods in Multipath Environments for Millimeter Waves

    , M.Sc. Thesis Sharif University of Technology Karimi, Parisa (Author) ; Farzaneh, Forouhar (Supervisor)
    Abstract
    The main objective of this project is to discuss a DOA estimation system performance in a multipath environment. For this goal, first the basics of the DOA Estimation systems are discussed. Evaluation of different types of algorithms and choosing an appropriate one is an important step in this regard. Moreover the comparison of different array structures is necessary to choose the appropriate one. The major part of the project has been dedicated to discussion of multipath phenomenon as a major source of error in DOA estimation and studying the multipath mitigation algorithms to eliminate the aforementioned error. A model based on the concept of Bistatic Radar Cross Section is proposed to... 

    Evaluation and Improvement of DOA Estimation Methods in Dipole Antenna Arrays with Different Geometries

    , M.Sc. Thesis Sharif University of Technology Sasannia, Zahra (Author) ; Farzaneh, Forouhar (Supervisor)
    Abstract
    In this thesis, some of the well-known DOA algorithms namely Bartlett, Capon, Linear prediction, Maximum Entropy, Pisarenko harmonic decomposition, Minimum norm and MUSIC are analyzed and compared with each other in the identical situations using a uniform linear array. Then based on these comparisons, the appropriate algorithm is selected. In the next step since the linear arrays can't estimate both angles of arrival (Azimuth and Elevation) simultaneously, two dimensional (2D) geometries are introduced and are also compared to each other. Then one of them (circular array) is selected for dipole antenna arrays. The performance of the selected array is evaluated using isotropic elements for... 

    Analysis and Simulation of Mars Rover Curiosity in the X and UHF Bands

    , M.Sc. Thesis Sharif University of Technology Torabi, Masoud (Author) ; Forouhar, Farzaneh (Supervisor)
    Abstract
    Mars rover Curiosity is a mobile scientific laboratory which it’s mission is to assess the biological potential of the landing site and characterize the geology of the landing region. This rover communicate to a Mars orbiter named MRO satellite in the UHF band which relies the signals to the Earth stations. Also this rover communicate to the Earth stations directly in the X band. In this thesis, we determine the technical characteristics of stations and simulate Earth-Mars radio links. So we calculate :
    1. determine the technical characteristics of Earth stations
    2. determine the technical characteristics of satellite and Curiosity
    3. Earth-Mars orbital position in the... 

    , M.Sc. Thesis Sharif University of Technology Razieh, Azad (Author) ; Farzaneh, Forouhar (Supervisor)
    Abstract
    In recent years due to the advances in semiconductor technology and the ability to implement small-scale manufacturing, communication at 60 GHz band receive more attention than ever has been. The use of this frequency band is not only about 7-9 GHz unlicensed broadband access provided, but getting smaller devices make it possible to use multiple antennas at the transmitter and receiver, and thus taking advantage of multiple input – multiple output systems. Antennas used in these systems should have features such as small size , low weight, high gain and bandwidth and also they should keep their high efficiency and gainat high frequency range (about a few GHz ). To achieve these features... 

    Switched Parasitic Antennas for the use in Wireless Communications

    , M.Sc. Thesis Sharif University of Technology Ahmady, Hesam (Author) ; Farzaneh, Forouhar (Supervisor)
    Abstract
    Switched Parasitic Antennas, as a kind of Smart Antennas, have several applications in Telecommunications and Radar systems. In the realm of wireless applications, these antennas provide the system with higher capacity owning to the fact that they are able to direct the main beam toward the desirable user. Moreover, they can be used to degrade the adverse effects of Multi-path. Multi-path reduction not only benefits mobile communication but applies to many applications of radar systems. These antennas, in addition, can be utilized in Direction Finding. In the case of other types of Smart Antennas, the above mentioned benefits can be achieved with high costs due to the fact that there are a... 

    Wideband Microwave Radio Direction Finding Based on Phase Interferometry Method for Two and Three Dimensional Arrays with Minimum Number of Antennas

    , Ph.D. Dissertation Sharif University of Technology Mollai, Sajjad (Author) ; Farzaneh, Forouhar (Supervisor)
    Abstract
    The interferometer method, as one of the most accurate schemes for wideband direction finding (DF), is used. The interferometer method has various algorithms which can be implemented depending on the required specifications. The advantages and disadvantages of these algorithms have been evaluated and the appropriate algorithm for a general practical case in view of the ambiguity resolution is proposed. The receivers’ channel phase tracking error is of significant concern in practice, in interferometric DF systems. The induced error due to channels phase tracking error is estimated. Furthermore the use of physically realizable antennas, achievement of high accuracy, minimum number of antennas... 

    Design and Simulation of mmWave Antenna Arrays with Novel 3D Geometries for 5G Wireless Applications

    , M.Sc. Thesis Sharif University of Technology Ahmadi, Nima (Author) ; Farzaneh, Forouhar (Supervisor)
    Abstract
    In the new generations of mobile communication systems, smart antennas are used to achieve higher capacities. Since these systems have the ability to form a radiation pattern where the desired signal is received with minimum distortion and inteferers are received with a significant attenuation therefore their application makes it possible to have a large signal to inteference ratio. In addition by setting the main beam direction towards the desired signal, it is conceivable to realize the the communication with a lower power. The optimal methods for angle-of-arrival estimation and beamforming in one and two dimensional structures has been studied in the literature, but the three dimensional... 

    Analysis and Design of a Multiple-Input Multiple-output (MIMO) Transmitter in the 60 GHz Band with a Beam Steering Capability Using All-digital Phase-locked Loop Chip

    , Ph.D. Dissertation Sharif University of Technology Salarpour, Mahdi (Author) ; Farzaneh, Forouhar (Supervisor)
    Abstract
    Multiple-Input Multiple-Output (MIMO) communications at millimeter-wave (mm-wave) frequencies (e.g., in the 60 GHz band) is a modern technology recently considered for various applications, such as emerging 5G services for multi-user MIMO (MU-MIMO) and high-resolution frequency-modulated continuous wave (FMCW) MIMO radars to support multi-gigabit throughputs in short-range environments via spatial multiplexing-diversity. Nevertheless, the impairments of communication channels in this frequency band, including significant propagation loss and severe blockage effect, are quite challenging to allow an efficient communication link. Hence, beamforming/beam steering can play a crucial role in 60... 

    Reliable and Uninterrupted Telecommunication link between Earth and Mars

    , M.Sc. Thesis Sharif University of Technology Ahmadi, Jamil (Author) ; Farzaneh, Frohar (Supervisor)
    Abstract
    For a manned space mission to Mars, one of the essential requirements is to have a two-way, uninterrupted communication link.Three Mars Synchronous Satellites (MSS), are proposed to ensure the telecommunication link in all locations on Mars (except its poles) at any time. At any given moment, at least two of the three satellites (MSS) is connected to the Deep Space Communication Complex (DSCC) (NASA Earth Station). But the use of MSS satellites is not adequate during the periods of solar conjunction and solar opposition. Due to the fact that the sun blocks or weakens the receiver signal, a solar orbiting satellite (SOS) is proposed to maintain the communication link at this condition....