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rahgozar--arash
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Hegel's ontology of power : the structure of social domination in capitalism
, Book
Cambridge University Press
2020
Value-based Optimal Design of FPB and LRB Isolators for Short to Medium Rise Buildings
, Ph.D. Dissertation Sharif University of Technology ; Esmail Pourestekanchi, Homayoon (Supervisor)
Abstract
Seismic base isolation is the most effective method of protecting and strengthening structures against seismic damage caused by large to small earthquakes and aftershocks. Providing damping and energy absorption of the seismic isolation at the structure's base level can significantly reduce the cost of repairing and strengthening the structure in addition to reducing seismic damage. However, besides these advantages, due to their high cost, seismic isolations in major infrastructure projects, hospitals, and crisis management centers should have economic and social justification. In this regard, a value-based seismic design approach can justify this important issue. In recent years of...
Buckling of Laminated Composite Plates with Elastically Restrained Boundary Conditions
, M.Sc. Thesis Sharif University of Technology ; Kochakzadeh, Mohammad Ali (Supervisor)
Abstract
This paper presents a unified solution to buckling analysis of rectangular symmetrically laminated composite plates with elastically restrained edges. The plates are subjected to biaxial compression and boundary conditions are simulated by employing uniform distribution of linear and rotational springs at all edges. The buckling loads and corresponding mode shapes are obtained based on classical lamination theory and using the Ritz method with simple polynomials as deflection function without any auxiliary functions. The verifications of current study are carried out with available combinations of classic boundary conditions in the literature. Through parametric study with wide range of...
Investigating the Role of Nano Catalysts of Carbon Quantum Dots Doped by Small Biomolecules in the Formation of Carbon-Nitrogen Bonds
, M.Sc. Thesis Sharif University of Technology ; Kalhor, Hamid Reza (Supervisor)
Abstract
Carbon Quantum Dots (CQDs) are a new class of zero-dimensional carbon-based nanoparticles with a size range from 1 to 10 nanometers. In this study, it was tried to form new carbon-nitrogen bond in organic synthesis using non-metal CQD-catalysis, thereby taking a significant step towards enhancing the catalytic role of carbon nanoparticles. Carbon-nitrogen bond is of paramount importance in biology and organic chemistry. In this regard transamidation reaction, reductive amination, and thioureas syntheses as three important reactions in organic chemistry were explored using non-metal CQD-catalysis. Transamidation is mainly used to produce new amides by forming carbon-nitrogen bond. This...
On optimal lead rubber base-isolation design for steel moment frames using value-based seismic design approach
, Article Soil Dynamics and Earthquake Engineering ; Volume 164 , 2023 ; 02677261 (ISSN) ; Esmaeil Pourestekanchi, H ; Mirfarhadi, A ; Sharif University of Technology
Elsevier Ltd
2023
Abstract
This paper employs the framework of value-based seismic design to optimize the geometrical and mechanical properties of lead rubber bearings (LRBs). An optimization problem is proposed within this framework. Construction cost and seismic consequences are chosen as the value components. Most failure modes of the LRB, such as strength deterioration, axial buckling, and rubber rupture, have been carefully considered in the seismic response. Besides, a new cost function for LRBs is developed from actual isolated building projects. Moreover, the minimum code requirements for lead rubber isolated buildings are formulated as the design constraints. FEMA P-58 methodology is exploited to predict the...
On optimal triple friction pendulum base-isolation design for steel moment-frame buildings employing value-based seismic design methodology
, Article Journal of Building Engineering ; Volume 63 , 2023 ; 23527102 (ISSN) ; Esmaeil Pourestekanchi, H ; Mirfarhadi, A ; Sharif University of Technology
Elsevier Ltd
2023
Abstract
This paper uses the value-based seismic design methodology to optimize the mechanical and geometrical properties of triple friction pendulum bearings (TFPBs). An optimization procedure is proposed within this methodology. Initial construction cost and lifetime seismic losses are picked as the value components. Extreme failure conditions of the TFPB, less considered in the current literature, such as the uplift and exit failure modes of the curved surface sliders at the end edges, have been carefully considered in the seismic behavior of the structure. Besides, the minimum code provisions and practical limitations (e.g., the critical overturning diameter of sliders) for friction pendulum...
Design and fabrication of a new expandable transtibial liner with manual volume control: A prototype
, Article Journal of Biomedical Physics and Engineering ; Volume 10, Issue 4 , 2020 , Pages 543-548 ; Aminian, G ; Farahmand, F ; Rahgozar, M ; Sharif University of Technology
Shiraz University of Medical Sciences
2020
Abstract
Diurnal volume changes is one of the main factors influencing socket fit in trans-tibial prosthesis and causing pressure problem issues. Embedded bladder liners have been recently a potential approach to deal with this problem. The aim of this technical note was to introduce a new transtibial silicone liner designed based on hybrid socket theory. To make expandability in the liner, an integrated wax structure was constructed over the selected areas of the positive model and then removed after lamination process. In addition, a mechanical system with manual control was designed to fit the liner with the residual limb volume by pumping the water in or out of the liner through connec-tive...
Efficient rule based structural algorithms for classification of tree structured data
, Article Intelligent Data Analysis ; Volume 13, Issue 1 , 2009 , Pages 165-188 ; 1088467X (ISSN) ; Chehreghani, M.H ; Lucas, C ; Rahgozar, M ; Ghadimi, E ; Sharif University of Technology
2009
Abstract
Recently, tree structures have become a popular way for storing and manipulating huge amount of data. Classification of these data can facilitate storage, retrieval, indexing, query answering and different processing operations. In this paper, we present C-Classifier and M-Classifier algorithms for rule based classification of tree structured data. These algorithms are based on extracting especial tree patterns from training dataset. These tree patterns, i.e. closed tree patterns and maximal tree patterns are capable of extracting characteristics of training trees completely and non-redundantly. Our experiments show that M-Classifier significantly reduces running time and complexity. As...
About Space Time
, M.Sc. Thesis Sharif University of Technology ; Rastegar, Arash (Supervisor)
Abstract
Einstein's general theory of relativity is an admirable successful and unifier geometrical modeling among concepts of space, time and gravity. This theory along with special theory of relativity made a massive change in our physical view and this, especially in its historical context, has deep and interesting consequences in man's philosophical viewpoint which can be studied. Some parts of this thesis relates to these consequences. Some of these interesting consequences may be hidden by computional or mathematical viewpoint and often these equations do not contain enough intuition. in one part, we provide a formulizatin of Einstein's equaion that is intuitional which can be translated in...
Tropical Algebraic Geometry
, M.Sc. Thesis Sharif University of Technology ; Rastegar, Arash (Supervisor)
Abstract
Tropical algebraic geometry is a fairly new branch in geometry which is called so in honor of Brazilian mathematician Imre Simon who was pioneer of this field.The set equipped with the addition and multiplication is a semifield.Algebraic geometry objects like algebraic varieties can be defined over.Polynomials and rational functions are defined over.The functions that they define are piecewise linear and concave functions and the set of points where they are nonlinear is a tropical variety which is a concave polyhedral. Thus, tropical algebraic geometry is a piecewise linear version of algebraic geometry.Another approach to tropical algebraic geometry comes back to the works of Russian...
Evaluating the Effect of Crumb Rubber on the Fracture Properties of Asphaltic Materials Using a Standardized Composite
, M.Sc. Thesis Sharif University of Technology ; Motamed, Arash (Supervisor)
Abstract
Fatigue cracking has a major impact on the performance of flexible pavements. Many test methods have been established to evaluate and estimate the fatigue life of asphaltic materials. Most of these test methods cannot successfully examine the fatigue properties of asphaltic materials. Recent studies demonstrate that using a standardized composite, which consists of glass beads and asphalt binder, can simulate the stress states that binder experiences in the field. This research used standardized composite to investigate the effect of crumb rubber on the fracture properties of asphaltic materials. To validate the test results, the authors conducted fracture tests on the Fine Aggregate Matrix...
Novel View Synthesis Using Light Field Camera
, M.Sc. Thesis Sharif University of Technology ; Amini, Arash (Supervisor)
Abstract
In the last two decades, novel view synthesis has become increasingly important in the movie and game industries. The new generated views correspond to virtual viewpoints, where no real camera has taken snapshot. Depending on the amount of available information from the scene, different approaches have been proposed to create novel views. If the depth information is available, then by knowing camera relative motion, novel views can be constructed. The conventional cameras only record the intensity of the captured scene, and discard the depth information. In the recent concept of light field cameras, by locating an array of micro-lenses between the camera sensor and the main lens, one can...
Developing a New Method to Evaluate and Quality Control of Chip Seal
, M.Sc. Thesis Sharif University of Technology ; Motamed, Arash (Supervisor)
Abstract
Chip seal is one of the most economical pavement maintenance practice that extends pavement life. To ensure chip seal good performance several quality control methods have been developed. However, most of these methods are qualitative and only measure the stone loss under a certain number on loading. This research developed a new method for quality control of chip seal, based on the assumption that characteristics of the bond between chips and pavement surface play a key role in chip seal performance. To validate this test method, the authors used a wheel track loading test. The results from this research clearly showed that the characteristics of the bond between chips and pavement surface...
Investigating the Effect of Various Additives on the Curing Time of Chip Seal and Chip Seal Treatments in Different Climate Conditions.
,
M.Sc. Thesis
Sharif University of Technology
;
Motamed, Arash
(Supervisor)
Abstract
Recently, a new method to investigate chip seal performance has developed by a research team at Sharif University of Technology. This study investigates the effect of various additives such as CRM, SBR Latex, Hydrated Lime and Ordinary Portland Cement (OPC), on the curing time of chip seal by this method. In addition, the chip seal treatments were investigated in different climate conditions like Wet and Wet-Freeze zones. The overall performance of mixture specimens evaluated using creep loading test. In fact, the bonding properties between aggregates and surface of Hot Mix Asphalt measured. The test results were analyzed by using of the work and time parameters. These parameters were...
Brandom’s Conception of Trust
, M.Sc. Thesis Sharif University of Technology ; Abazari, Arash (Supervisor)
Abstract
A Spirit of Trust results from Brandom's thirty-year effort to give a pragmatistic reading of Hegel's Phenomenology of Spirit. In A Spirit of Trust, Brandom reformulates Hegel's arguments in the language of contemporary Analytical Philosophy and gives a unique interpretation of Hegel's key concepts. In this Thesis, we will examine one of its key concepts, namely, Trust; We will pursue the following questions: First, What is Trust? And what is its connection to other aspects of Brandom's philosophy? Second, How does Trust help us in overcoming Alienation? Third, Are Confession and Forgiveness, which are the constitutive concepts of Trust, psychologistic or normative? Fourth, What is the...
Design of Stress Absorbing Membrane Interlayer (Sami) and Overlay to Reduce Reflective Cracking
, M.Sc. Thesis Sharif University of Technology ; Motamed, Arash (Supervisor)
Abstract
Cracks or construction joints in an overlayed pavement can propagate into the overlay over time due to various factors, the most important of which are traffic and temperature loading, and cause premature failure of pavement. This propagated cracks are called reflective cracks and the phenomenon of crack propagation into the overlay is called reflective cracking. Use of stress-absorbing membrane interlayers (SAMI) is one of the ways can reduce the occurrence of reflective cracking and/or delay it. One of the most common SAMIs is an asphalt mixture consists of bitumen and aggregate layed down between the old and the veneer layers. The function of the SAMI depends on several factors such as...
An Investigation on the Effect of Filler Type and Content on the Performance of Asphaltic Materials
, M.Sc. Thesis Sharif University of Technology ; Motamed, Arash (Supervisor)
Abstract
The objective of this research is evaluating the effect of filler type and content on the characteristics of asphaltic materials. The properties of the asphalt mixture are greatly influenced by its components. As asphalt mixtures are composed of two prominent components, aggregates and binder, the change in type and contents of these materials may lead to altering the performance of asphalt mixtures. Aggregates in the asphalt mixtures are categorized into three groups based on their particle sizes: coarse aggregate, fine aggregate and mineral filler. The effect of filler on the characteristics of asphalt mixtures can be examined by changing the type and content of filler and holding the...
The Analysis of HDR Video Reconstruction Methods
, M.Sc. Thesis Sharif University of Technology ; Amini, Arash (Supervisor)
Abstract
The conventional cameras and displays do not have the ability to record and display the full brightness of the world around us. These deficiencies have led to the development of methods known as High Dynamic Range Imaging. Most of the work done in this field falls into two groups: compression of the light range and its expansion. In compression, the brightness range is intended to display content with a high dynamic range in simple displays. But the goal of expanding the brightness range is to reconstruct HDR content from a low dynamic range one. In addition to the above classification, this field is also categorized based on the type of content (image or video). In this study, the...
Investigating Different Crumb Rubber Modification Methods in Cold Mix Asphalts
, M.Sc. Thesis Sharif University of Technology ; Motamed, Arash (Supervisor)
Abstract
Studies have shown that use of crumb rubber additive can improve the mechanical and performance properties of hot mix asphalts. Nowadays, different methods are used for adding crumb rubber to asphalt mixtures. However, no comprehensive research has been done to investigate the effects of these different methods in cold mix asphalts. In this research, different crumb rubber modification methods were evaluated to compare their effects on cold mix asphalts’ performance. In this regard, various crumb rubber modification methods, such as pre blending crumb rubber into the asphalt before emulsification, post blending crumb rubber into the prepared asphalt emulsion and blending crumb rubber with...
Scene Reconstruction Using Light Field Camera
, M.Sc. Thesis Sharif University of Technology ; Amini, Arash (Supervisor)
Abstract
Nowadays in movie and photography industry, scene reconstruction is of high importance. Capturing data containing the depth information of the scene can help us achieve this goal more easily. Ordinary Cameras do not record depth information of the scene so they can’t ease our task. In 2005, some Stanford Researchers, inspired by Adelson’s work, were able to build the first camera that captures depth information. They called it the light filed camera. In these cameras an array of microlenses is inserted below the main lens. By doing this the camera is able to capture the rays’ intensities and their directions in space too. With this kind of information, we are able to obtain the depth of a...