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Numerical Study of Bearing Capacity of Shallow Foundations on Two-Layer Soils
, M.Sc. Thesis Sharif University of Technology ; Ahmadi, Mohammad Mahdi (Supervisor)
Abstract
The purpose of designing the foundation is to transfer the load of the structure to the subsoil without creating shear failure and additional settlement in the soil. Therefore, choosing the appropriate bearing capacity is an important point that should be considered in any project. Determining the bearing capacity of foundations is one of the topics that has long been considered by researchers and geotechnical engineering designers. For this reason, its design is not considered a new issue, but the application of new methods and the development of computers, raises new perspectives on this issue that justifies new studies.Most of the recent study, which have done so far on bearing capacity,...
Aeroelasticity consideration of supersonic vehicle using closed form analytical aerodynamic model
, Article Aircraft Engineering and Aerospace Technology ; Volume 81, Issue 2 , 2009 , Pages 128-136 ; 00022667 (ISSN) ; Salezadeh Nobari, A ; Mahdi, S ; Hassan, H ; Farhad, T ; Sharif University of Technology
2009
Abstract
Purpose - The purpose of this paper is to investigate the aeroelastic behavior of a supersonic flight vehicle flying at moderate angles of attack using global analytic nonlinear aerodynamic model. Design/methodology/approach - Aeroelastic behavior of a supersonic flight vehicle flying at moderate angles of attack is considered, using nonlinear aerodynamics and linear elastodynamics and structural models. Normal force distribution coefficient over the length of the vehicle and pitching moment coefficient are the main aerodynamic parameters used in the aeroelastic modeling. It is very important to have closed form analytical relations for these coefficients in the model. They are generated...
Using Compartment Modeling for the Non-Invasive Diagnosis of Malignant Tumors, as Well as Determining the Active Volume and Total Glycolysis of Malignant Tumors in PET/CT Imaging with FDG Radiation
, Ph.D. Dissertation Sharif University of Technology ; Hosseini, Abolfazl (Supervisor) ; Sheikhzadeh, Peyman (Co-Supervisor)
Abstract
In static PET/CT imaging, the Standardized Uptake Value (SUV) parameter is used to evaluate diseases. The use of this parameter provides valuable information to physicians in many cases. However, this parameter has limitations and is not suitable for certain clinical applications, such as assessing treatment response and differentiating between benign and malignant tumors. In contrast, utilizing dynamic imaging systems can yield significant information through the extraction of kinetic features and quantitative analysis based on temporal data. However, the use of dynamic PET imaging in a clinical setting can be challenging due to factors such as prolonged scan times (> 60 minutes),...
Investigation of Electro-Optical Properties of Heterostructures based on 2-D Layered Materials by Quantum Simulation
, M.Sc. Thesis Sharif University of Technology ; Simchi, Abdolreza (Supervisor) ; Shayeganfar, Farzaneh (Supervisor)
Abstract
Density Functional Theory is one of the most robust Ab-intio methods for describing the structural and electronic properties of a wide range of materials. The ability to predict the material properties changes due to targeted material manipulation at the atomic scale has reduced the cost of many empirical experiments. It has improved the knowledge and understanding of the investigation and producing new materials and devices. Tow dimensional heterostructures are highly regarded due to their unique optoelectronic properties, potential application in nanoelectronic devices, energy storage devices, solid-state devices, and photovoltaic devices. In this study, the two-dimensional materials...
Theoretical study of borazine: cation-π (Be 2+, Mg 2+, and Ca 2+) interaction
, Article Structural Chemistry ; 2012 , Pages 1-7 ; 10400400 (ISSN) ; Sharif University of Technology
2012
Abstract
The geometries of the complexes of Be 2+, Mg 2+, and Ca 2+ metal cations with borazine ring were studied. The complexes were optimized at the B3LYP level and the 6-311++G(d,p) basis set. Then, the interaction energies corrected by basis set super position error were calculated in the same level. The results show that interaction energy is strongly dependent on the charge-to-size ratio of the cation. Therefore, Be 2+ cation has the most interaction energy value with respect to Mg 2+ and Ca 2+ metal cations. Natural bond orbital analysis was performed to calculate the charge transfer and natural population analysis of the complexes. Quantum theory of atoms in molecules was also applied to...
A new model for deformed carbon nanotubes using Green's function
, Article Applied Physics A: Materials Science and Processing ; Volume 105, Issue 4 , 2011 , Pages 875-880 ; 09478396 (ISSN) ; Sarvari, R ; Sharif University of Technology
2011
Abstract
A new method for modeling and analysis of deformed carbon nanotubes (CNTs) using Green's function, is presented in this paper, for the first time. Using the proposed method, a new circuit model is obtained for the deformation region of a deformed single-walled CNT (SWCNT), which the values of its elements depend on the type of deformation and also the deformation parameters such as the coupling matrices and the energy variations of deformation region. The comparison between the obtained results from the analysis of proposed model and the literature gives a good match which approves the accuracy and correctness of the proposed model
A Metabonomics Study of Samples of Different Diseases: Investigation of Linear and Non-Linear Model by Nuclear Magnetic Resonance
, Ph.D. Dissertation Sharif University of Technology ; Tafazzoli, Mohsen (Supervisor)
Abstract
Metabonomics is a quantitative measurement of time dependent metabolic interactions for living systems in response to the pathological or genetic variations. NMR spectroscopy has emerged as a key tool for understanding metabolic processes in living systems. In this project, the study of metabolomics was performed as classification and regression on samples of parkinson’s disease, multiple sclerosis disease, celiac disease and crohn’s disease. In classification part, various methods were applied using optimal parameters.classification methods in Parkinson’s disease, multiple sclerosis disease, celiac disease and crohn’s disease were RF, CART, PLS-DA, RF and RF respectively. Based on the...
groundwater level fluctuations forecasting using conjunction models of Wavelet - Neural-Fuzzy Network (WNF) and Wavelet-Neural Network (WNN) and linear model of ARIMA (case study: Qom plain
,
M.Sc. Thesis
Sharif University of Technology
;
Shamsaei, Abolfazl
(Supervisor)
Abstract
Prediction of groundwater level fluctuations is absolutely necessary for the proper manag ement of these precious resources. There are different methods to predict hydrological time series such as groundwater level. Linear models inefficiency in predicting nonlinear and n on-stationary time series cause researchers widely use artificial intelligence techniques such as Artificial Neural Networks (ANN), Fuzzy Inference System (FIS), Genetic Algorithm (GA) and their hybrid models such as Artificial Neural – Fuzzy Inference System (ANFIS). These smart models are capable to simulate nonlinear and non-stationary time series in suitable accu-racy using by a few time and data. By emersion of Wavelet...
Numerical Modeling of Rocking Of Shallow Foundations Subjected to Slow Cyclic Loading with Consideration of Soil-Structure Interaction
, M.Sc. Thesis Sharif University of Technology ; Haeri, Mohsen (Supervisor)
Abstract
Foundation is the lowest load-bearing part of a structure and a part of underneath soil that is affected by the structure load. In fact, foundation transfers the loads from the superstructure to the substructure, preventing excessive settlement of soil or stresses exceeding soil bearing capacity. Indeed, almost all structures are placed on the ground, therefore the effects of soil and structure on each other, which is known as Soil Structure Interaction (SSI), is considered as a key factor in many important and engineered structures. In contrast to structures on a rigid footing, a flexible foundation may show stiffness degradation along with an increase of damping and natural period of the...
Controller Design to Reduce Effects of Radome Error Slope on the Stability of Misssile
, M.Sc. Thesis Sharif University of Technology ; Fathi, Mohsen (Supervisor)
Abstract
In this project three models addressed before in the references are reviewed and the stability margins of radome error slope obtained by analytical method. Then a new model who is usefull in practical applications presented. Because of complication of this model the model is simplified and stability margins for radome error slope derived in simplified model. It is also shown that simplified applicative model is similar to model purposed in ref. [6]. Then a PD controller designed to stabilize some of models reviewed in chapter 3. The equations derived before verified in continuation of the project. The effects of parameters on the stability of missile analysed by equations derived in chapter...
Experimental Study of Common Refrigerants Replacement with Hydrocarbon Mixture in Automotive Air Conditioning System
, M.Sc. Thesis Sharif University of Technology ; Soltanieh, Mohammad (Supervisor)
Abstract
Due to the environmental concern for the harmful effect of the release of HFCs on global warming there has been more interest for the use of hydrocarbons as refrigerants in recent years. In this project the performance of these refrigerants have been studied and compared with common refrigerants from the quantitative and qualitative point of view using a real-scale model of Peugeot-405 air conditioning system. Charging amount, inside temperature, cooling load, energy consumption of cycle, coefficient of performance and required time to steady state condition are the important comparative criteria for such a study. After carrying out a series of tests it has been considered that charge...
Context-Specific Reconstruction and Gap-Filling of Metabolic Networks by Sparse Reconciliation of Data Inconsistencies
, M.Sc. Thesis Sharif University of Technology ; Tefagh, Mojtaba (Supervisor)
Abstract
With the increasingly collected biological data, appropriate usage of this data is of great importance for understanding and predicting biological systems and has been the aim of experiments and data collections. A famous category of biological data is known as “omics” which refers to transcriptomics, proteomics, metabolomics, and fluxomics, from different cells or tissues in various media and conditions. This set of data is regularly used for tasks such as studying cells and organisms, understanding cell states, cancer prediction, etc. and is of great importance in Systems Biology.In this thesis, we concentrate on studying cells or organisms using such data, where during that process, we...
Design of an Optimal Site Deployment Procedure in Different Air-Defense Scenarios
, M.Sc. Thesis Sharif University of Technology ; Fathi, Mohsen (Supervisor)
Abstract
One of the most important issues among defense is the increasing of the defense power using present facilities. Therefore, optimal setting and arrangement of equipment by considering different air-to-earth attack of enemy without knowing of properties and capabilities of available systems may not be possible. So, using defense equipment considering properties of them, and paying attention to existence restrictions and effective elements can have an effective role with the design of suitable algorithm.The main purposes of this thesis are: maximization of the efficiency of a defense system against. aerial invader targets, achieving the best arrangement of defense equipment based on suggested...
Transfer Alignment Algorithm Development for Aerial Launch Space Launch Vehicle Navigation System Using the Carrying Airplane Navigation System
, M.Sc. Thesis Sharif University of Technology ; Fathi, Mohsen (Supervisor)
Abstract
In this research the problem is the development and simulation of Transfer Alignment algorithm for an aerial launch space launch vehicle. In the references there is no complete study on development of this algorithm for the case space launch vehicle. In order to develop the algorithm, the carrying airplane and the space launch navigation systems are considered as the Master INS and Slave INS respectively. First a 6DOF simulation of the airplane is presented. Then the desired inputs for simulation of Master and Slave INS are generated. Also the differences of the inputs of Slave INS caused by the distance between the Master and Slave INS is considered. Master INS performs as an ideal INS and...
Optimal Online Guidance Algorithm of the Flexible Launch Vehicle under the Occurrence of Random Failure in the Propulsion System in Order to Inject the Satellite into the Orbit
, M.Sc. Thesis Sharif University of Technology ; Fathi, Mohsen (Supervisor)
Abstract
The purpose of this thesis is to provide an optimal and online flexible launch vehicle guidance algorithm and method under the occurrence of a random failure in the propulsion system in order to inject the satellite in the nominal orbit/the closest orbit to the nominal orbit. In addition, by recognizing the effects caused by the fault in the propulsion system on the flight dynamics of the launch vehicle, appropriate guidance decisions are applied in analyzes and calculations, and the flexible launch vehicle, according to the amount of error and the time of occurrence of the error and the amount of time left to reach the rated orbit, reaches the nominal orbit or the closest orbit to the...
Borsuk–Ulam Theorem and an Introduction to Topological Combinatorics
, M.Sc. Thesis Sharif University of Technology ; Jafari, Amir (Supervisor)
Abstract
Topological combinatorics is an almost novel branch in mathematics whose dawn began to shine originally from Lovász studies at late 70's. The main purpose of the pursued subjects in this branch is to apply topological methods in order to conclude various combinatorial results based on the famous Borsuk-Ulam's theorem which itself is a very deep statement in algebraic topology and has many equivalent versions. For instance, one of these versions states that there is no continuous map f:S^n⟶S^(n-1) which behaves antipodally. In this thesis, we intend to take a considerably long journey in homology theory to pave the way toward a complete proof of this theorem and some of its generalizations....
Mission Based Launch Vehicle Optimal System Design Software Development Including Graphical Interface
, M.Sc. Thesis Sharif University of Technology ; Fathi, Mohsen (Supervisor)
Abstract
With the advancement of the space industry and the expansion of space missions, the need for satellites and spacecraft with more precise sensors and equipment has increased, which in turn increases the payload mass. In today's world, designing launch vehicles that are merely suitable for the mission is not enough; the launch vehicle must be the best and most appropriate system. The best launch vehicle system is one that not only performs the mission well but is also cost-effective, has higher efficiency, higher reliability, and is easier to maintain. This project aims to develop a multi-disciplinary launch vehicle design software with a graphical interface. In this project, using a...
Magnetoresistance due to domain wall bulging
, Article Journal of Magnetism and Magnetic Materials ; Volume 322, Issue 16 , August , 2010 , Pages 2401-2404 ; 03048853 (ISSN) ; Phirouznia, A ; Sharif University of Technology
2010
Abstract
The effect of bulging of domain wall (DW) on the magnetoresistance (MR) is investigated. With taking into account the auto-correlation between the points of the interface, one can formulate the mobility within the relaxation time approximation scheme. The results show that the bulging of DW, evaluated with the commonly accepted magnetic parameters for typical ferromagnetic materials of Co, Fe and Ni, has a countable role into the MR
Eye detection and tracking in video streams
, Article IEEE International Symposium on Communications and Information Technologies: Smart Info-Media Systems, ISCIT 2004, Sapporo, 26 October 2004 through 29 October 2004 ; Volume 2 , 2004 , Pages 1258-1261 ; 0780385934 (ISBN) ; Manzuri, M. T ; Sharif University of Technology
2004
Abstract
This paper presents a new method for eye detection in a sequence of video pictures. We first find the face region using the features of skin's color, then the location of eye is determined by applying three cues on the detected face region. The first cue is the eye intensity and color, because the intensity of each eye region is relatively low and its color differs from the color of surrounding skin. The second cue is based on the position and size of eyes. The third cue is based on the convolution of proposed-eye-variance-filter with the eye-window candidates. After finding the precise location of eye, it will be tracked in a finite search window. We have evaluated and tested the presented...
Simulation and Optimal Control of Electric Arc Furnace
, Ph.D. Dissertation Sharif University of Technology ; Saboohi, Yadollah (Supervisor)
Abstract
The study presents a comprehensive electric arc furnace model for simulation and control application to predict chemical processes, heat and mass transfer. The model consists of arc module, chemical – slag module and heat transfer sector to observe fundamental phenomena affecting on energy consumption. Two modules act independently of each other and the two module calculations apply in the heat transfer sector. Arc module predicts the amount of energy dissipated from the arcs using arc currents and arc lengths; chemical and slag module calculates chemical energy, changes of elements/compounds, slag height and slag quality; while the heat-transfer sector uses calculations of the other two...