Sharif Digital Repository

Congestion is the inseparable part of everyday life in large transportation networks. Expansion of road networks especially in downtown area is next to impossible and it is resulting multiplicative congestion problems. Congestion imposes private and public costs. Therefore, restricting policies on road use through cordon-based or area-based pricing is proposed to reduce the negative impacts of traffic, travel demand management and optimal use of transportation systems. This would produce better resource allocation through transportation network optimization. Implementation of congestion pricing policies induces short-term and long-term effects. In this thesis, it is attempted to determine... 

” The story of the "Weil conjectures" is a marvelous example of mathematical imagination, and one of the most striking instances exhibiting the fundamental unity of mathematics.”In 1949,Andre Weil stated some conjectures on the zeta function of Algebraic varieties over finite fields .These conjectures were analogue of the properties of Riemann zeta function ,in particular Riemann hypothesis.In fact ,Weil built a bridge between Diophantine structure on varieties over finite fields (Counting of rational points on varieties) and cohomological structure of them over the field of complex numbers(topology of variety).In this thesis, first we state Weil’s motivations for these conjectures and state... 

Compared to systematically signalized intersections, in the absence of any systematic instruction or signalization at unsignalized-prioritized intersections and due to lower levels of control, driver performance strongly steps in as a decisive factor of intersection traffic and geometric design. Therefore, the study of driver behavior at these intersections appears necessary. This thesis aims to study driver behavior at four prioritized intersections where the minor stream has to yield right of way to the main stream in the city of Mashhad, Iran. Following extraction of raw statistical data from extensive filming, the initial database was constructed consisting of 29 variables. Based on the... 

Carbon dioxide is one of the most significant greenhouse gases in biocycle. This gas makes the equilibrium temperature by absorbing IR radiations on the earth. It is the reason that prevent the earth from freezing. Increasing CO2 emissions in atmosphere, makes problems such as global warming. According to the Kyoto Protocol, all the countries attended to this protocol, must decrease greenhouse gases emissions. Although H2 fuel is one of the best alternative fuel against fossil fuels, the most important industrial process (steam-methane reforming) produce CO2 as by-product. Thus, gas separation has a prominent role in industrial processes such as CO2 capture and H2 purification.Today, gas... 

In the present work we first introduced ILIDS and review the theory of interferometry and light scattering from droplets. Bases on ILIDS method, droplets are irradiated by monochrome sheet laser, where the superposition of reflected and first-order refracted beams form a parallel fringe pattern at out of focus plane on the imaging sensor in the forward-scatter region. This pattern can be related to the droplet size by using simple geometrical optics. For the present work, an image processing algorithm is utilized to capture weak and noisy images of droplets to reduce the lost data in the sizing procedure. Since ILIDS method is applied for small and dilute spray, it is suitable for... 

In this research, nanocomposite containing reduced graphene oxide nanosheets (RGO) and trimetallic three-dimensional (3D) Pt-Pd-Co porous nanostructures was fabricated by galvanic replacement technique. First, GO suspension was drop-casted on the electrode surface, then GO film reduction was carried out by cycling the potential in negative direction to form the RGO on GCE (RGO/GCE). Then, electrodeposition of the cobalt nanoparticles (CoNPs) as sacrificial seeds was performed onto the RGO/GCE by using cyclic voltammetry. Afterward, Pt-Pd-Co 3D porous nanostructures fabrication occurs through galvanic replacement method based on a spontaneous redox process between CoNPs and solution... 

In some cases, Mehrotra’s predictor–corrector algorithm might make very small steps in order to keep the iterate in a certain neighborhood of the central path, and thus implying the inefficiency of the algorithm. In this study, a different approach for controlling the iterates on the algorithm is investigated, which was recently introduced by Salahi and Terlaky. The approach is based on postponing the choice of the barrier parameter. To do so, a step size is fixed in the corrector step and then by solving a one dimensional optimization problem, the barrier parameter is computed. Finally, using the computed barrier parameter, the next step is taken. It has already been proved that the new... 

According to Davidson the distinction between the conceptual scheme and the empirical content is the last dogma of empiricism, and its abandonment will amount to abandoning what has remained from empiricism. To him, conceptual schemes are ways of organizing experience or systems of categories that form the data of sensation or fact, contents being data of sensation or facts which are neutral and out of all schemes. While Quine seems committed to such a distinction, Davidson provides arguments to show that the distinction is untenable. This discrepancy between Quine and Davidson is what this dissertation elaborates on. More specifically, the dissertation pursues two main aims: to show in... 

The phenomenon of relativistic self-focusing in nuclear fusion and laser-plasma interactions is very important. Under the influence of this phenomenon, the laser beam can move in plasma a few Rayleigh lengths and the interaction efficiency is improved. The relativistic self-focusing in inhomogeneous, homogeneous, collisional and collisionless plasmas has been studied in various conditions of plasma and laser in classical physics. In this thesis the propagation of a laser pulse at the X-ray wavelength range and its relativistic self-focusing in quantum plasma is investigated by numerical simulations. Initially, the interaction with a collisionless ramped density profile plasma target is... 

Frank Jackson’s knowledge argument is presented to show the falsity of physicalism. The argument is based on a famous thought experiment according which, Mary, a genius scientist who has spent her whole life investigating the neurophysiology of vision in a black-and-white environment, in spite of acquiring complete physical knowledge in that field, knows nothing about the phenomenological properties of seeing red. The knowledge argument has three main steps: proofing the existence of an epistemic gap, inferring an ontological gap from the epistemic gap and inferring the falsity of physicalism from the ontological gap. Different criticisms are made of each step. One of the criticisms of the... 

Type and terms of payment is one of the most important fundamentals of any construction project contract. Suitable contract type is selected based on available financial options, payment systems, project schedule and other uncertainties of project environment. Commonly in Iran; private residential construction projects are executed using cost plus or lump sum contracts. Based on project’s contract type, costs of materials’ waste are to be borne by different parties. For example in cost plus contracts, the costs of materials as well as wastes are paid by owner while in lump sum contract this cost is paid by contractor. Considering limited budget of construction projects, materials’ waste... 

Energy Harvesting has been appeared as an approach in order to make the green communications possible. In Energy Harvesting systems, nodes extract energy from the nature to extend their lifetimes. The harvested energy can also be used for the purpose of communication and specially for the transmission process. Compared to the conventional batterypowered systems, the Energy Harvesting systems have access to an unbounded source of energy (like vibration absorption devices, water mills, wind turbines, microbial fuel cells, solar cells, thermo-electric generators, piezoelectric cells, etc). However, the diffused nature of this energy makes it difficult to be used for communication. In this work,...