Sharif Digital Repository

In this study, first nano structure powders of Fe3AL / Al2o3 by different percentages of reinforcement phases (10, 20 and 50 percent of volume) based on mechanical milling procedure was created. To do so, iron, Al and iron oxide (hematite) pure powder based on special weight percentages mixed with each other and milled in 20 to 100 hour periods based on two different weights of ball toward powder: 10 and 20. Morphological variations, particles sizes and powder densities, lattice strain and phase variations in different timing periods of mechanical milling process was studied by Scanning Electron Microscopy(SEM) , analyzing apparatus of particles sizes by laser , gaseous picnometer and X-ray... 

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 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... 

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... 

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... 

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... 

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... 

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... 

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... 

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... 

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... 

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... 

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... 

In the past few years, the available knowledge in graph-based processing has made significant progress, and as a result, powerful tools have been created. In this regard, graph learning with the assumption of data smoothness on the final result can be considered a successful example. Briefly, in graph learning, to describe the relationship between the problem components, a graph is learned using the available data whose nodes represent the problem components, and its edges represent how much these components are connected. The usefulness of this method lies in the possibility of using the obtained graph as the input to currently known methods of classification and achieving better results... 

Compressed sensing theory with the goal of sparse recovery using as few measurements as possible, has found much attention in the past decade. A fundamental assumption in compresses sensing is the linear nature of the measurements, that establishes a matrix equation between the unknowns and unknowns. However, in some applications, the physics of the problem may impose some type of nonlinear relationship between the unknowns and the measurements. Some solutions concerned with this type of problems,approximate the nonlinear relationship using a second order Taylor expansion. Using this approximation besides some modifications in the way the second order relationship is presented, a more simple... 

The design of deterministic sensing matrices is an important issue in compressive sensing in sparse signal processing. Various designs using finite field structures, combinatorics, and coding theory have been presented. The contribution of this thesis is designing many codes with large minimum distance using algebraic curves. Here, we initially design a algebraic-geometric code over a maximal curve in a Galoi field Fpm Afterwards, we map the code to the field Fp using trace map. This code has a large minimum distance. Using this code, we design a matrix with low coherence. One of the main issues in presented designs is that the number of matrix rows is considered to specific integers near... 

Crumb Rubber is one of the main polymer modifiers of binders. This modifier can improve chip seal performance against ravelling (aggregate loss). The most concerning distress in chip seal is ravelling. Aggregate loss is not restricted to the early life of chip seal, but continues throughout the service life. Chip seal can be made with hot binders or emulsion binders. These two type of binder were modified with 7% and 15% of crumb rubber in applicable way. Then, two major environmental effect on chip seal performance, freeze-thaw and asphalt aging, were investigeted based on laboratory test. For this purpose, authors used chip seal bonding test. Chip seal bonding test is developed recently... 

A^1-homotopy theory or the motivic homotopy theory is a homotopy theory for smooth schemes of finite type over a Noetherian base scheme of finite dimension. A^1-homotopy was introduced by Vladimir Voevodsky and Fabien Morel in the 90s. The fundamental idea of this theory is that for schemes the affine line A^1 should play the role of the interval I = [0,1]. A^1-homotopy has been proved to be an important theory. Some familiar cohomology theories like motivic cohomology and algebraic K-theory are representable in this theory. Motivic cohomology and A^1-homotopy theory also appear in Voevodsky’s proof of Milnor’s conjecture and Block-Kato conjecture. In this thesis,we will give an introduction... 

In this thesis we introduce Tropical Geometry and It’s Application in Arithmetic Geometry