Sharif Digital Repository

Regardless of the traffic model and its application, an essential input of transportation models is the amount of demand which is usually described using Origin-Destination (OD) matrices. Due to high costs and time of direct development of such matrices, they are estimated indirectly from traffic measurements recorded from the network. Dynamic Origin-Destination demand provides valuable information on within-day fluctuation of traffic demand which could be used in analyzing congestion dissipation. In addition, they are essential inputs of dynamic traffic assignment (DTA) models. The current study presents a fuzzy approach to dynamic OD estimation problem. The problem is designed as a two... 

Planning as one of the most important management tasks in all organizations is necessary and essential. Strategic planning is at the top of every organization’s decision-making, and it is important and crucial. Universities like other organizations cannot survive or thrive without a clear strategy. This study has done considering the importance of planning in universities and higher education institutions and discussing one of the challenges in this field. This challenge is analyzing the paradox of top-down planning and collective decision-making and the authority of faculty members in universities. It is an exploration research with the qualitative method and according to a case study of... 

Cryptocurrencies (cryptos), as a new type of money, are considered a medium of exchange, an investment asset, and a hedging tool in today's world. In 2008, bitcoin as the first cryptocurrency was introduced, which has survived through recent years and has gained more and more popularity every day. Cryptos are one of the first applications of blockchain, the technology that many expect to revolutionize the future world in different ways. We aim to investigate what affects the bitcoin price, based on artificial intelligence and, in particular, machine learning. First, we find features impacting bitcoin price via a thorough investigation of the literature. Then, applying machine learning and... 

According to the rapid growing in communication devices, users need higher rates for their usages. Fiber optics is one the major choices to support such rates. One of the simplest and cheapest networks is Local Area Network (LAN) as a Passive Optical Network (PON). In these networks, some computers are locally connected to a passive optical device and communicate through it. Multiple access to a shared channel is an important task in such a network. In this thesis, Code Division Multiple Access (CDMA) is used and a new algorithm for Multiple Access Control Sublayer (MAC) based on scheduling will be developed to improve Quality of Service (QoS) and stabilize the network.
In the scheduling... 

Scattering theory on locally symmetric space first was studied by Peter Lax and Ralph Phillips. They studied the and develop scattering theory on it. Without the Fourier analysis tools this theory was completed with a lot of computations. In this thesis first we try to construct Fourier analysis by definition Fourier transform then by means of new tools we prove very short version of scattering theory on locally symmetric space . In general case for studying scattering theory we need firs spectral decomposition of Hilbert space of square integrable functions locally symmetric spaces of rational rank one is achieved by quotient of symmetric space where G is Lie group and K is maximal... 

Lipases (Triacyl Glycerol Acyl Hydrolase, EC.3.1.1.3) are multidimensional biocatalysts which have many applications in food industrials, dairy, fats and oils processing, detergents, synthesis of pure chemical and pharmaceutical materials, paper industrial and cosmetics. Generally, industrial enzymes are produced extracellularly, so their separation from a low-cost complex medium (usually used for production) is one of the cost stages in their production process. Filtration is the most economical method of separation in the production of enzymes, but due to the small size of colloidal particles and cell masses present in the fermentation environment, its use is subject to limitations. In... 

Reviewing trends of energy consumption in the world reveals that sooner or later energy resources will be depleted. This concerning rate of consumption has brought about more greenhouse gases (GHG) emission influencing deleteriously on environment and climate. Human has continued energy consumption to maintain and improve the quality of his life through industrial production. Industry as a significant energy user owns considerable contribution to this consumption. Several attempts have been carried out to develop energy management systems in order to improve the energy efficiency of industrial sectors. Whilst they are comprehensive and could be applied to any sector, there is lack of... 

The Tilor welded blank (TWB) two or more sheets with different thickness or strength which are welded together. The automobile designer are searching for new methods to reduce the cars’ weight and producing cost in order to diminish fuel consumption so they can survive in the competitive market. One way to achieve to this seemingly Contradictory demands, is using TWB in cars’ body. One of the most applicable methods to investigate the formability of metals sheets, is Forming Limit Diagrams (FLD). Three ways to determine the FLD are: Analytical Method, Experimental Methods, and Numerical Method. The experimental method to determine FLD, require metal sheets to undergo in different strain... 

Guilt aversion, the process of avoiding guilt, when guilt indicates the human sense which is present when they let down other's expectations. As the definition suggests, guilt is related to what one thinks of the others’ thoughts; i.e. the second-order beliefs. Incomplete information models of guilt aversion are the most reliable ones in the literature due to economic experiments. Based on these models, the dictator game and the trust game are applied to measure the degree of guilt aversion. In both the above psychological games, there are two players where Player A has the power to decide about the split of the money. We use the amount of transferred money to Player B is as a sign of guilt... 

Scientists want to know how they can control fluids motion. They use electric fields for controlling the fluids in different dimensions. In small size, application of electric fields is very important because of biological applications. We use electric current and field for rotating freely suspended films. Here, we study soap, polar and non-polar liquids, MBBA liquid crystal and ferrofluids films. We show that the surface charge plays the crucial role in rotating the films.We study the correlation between rotation of a film and different physical quantities.Our experiments confirm that dipole moments of fluid molecules do not show a clear effect on the rotation. Increasing the dipole moment... 

Fluid-structure interaction plays an important role in the performance of various Microsystems. In many micro-devices such as micropumps, microvalves and micromixers, the fluid flow is driven by a vibrating solid membrane. Since the fluid also plays a role in resistance to the solid vibration and deformation, the solid vibration and the fluid flow are always coupled and a full fluid-structure interaction (FSI) analysis is required in order to investigate the performance characteristics of these devices. Since the frequency of the solid vibration is normally high in micro-devices, the time step size required for the finite element analysis of the fluid-structure interaction in these devices... 

The main objective of this research is to provide a framework by which decision-makers can evaluate and compare alternatives for sustainable development planning under uncertain dynamic future considering the risk and uncertainty associated with human judgment as well as the uncertain future. This approach combines the Delphi method, fuzzy set theory, and a discrete multi-criteria method based on prospect theory (TODIM). TODIM (an acronym in Portuguese for iterative MCDM) method is a particular multi-criteria approach based on the prospect theory. A qualitative Delphi technique is used to identify a set of qualitative sustainability criteria and to rate the alternatives accordingly. The... 

Unequal distribution of profit and income in different sectors of industries creates a challenge for investors and their managers to determine the level of concentration and investment in each industry sector. The energy industry, as one of the most important ones in the country, will not be an exception to this rule. Iran, as a country with a competitive advantage in the world in this industry, can take the path of development if this industry is used correctly and to the maximum. Also, owners, regulators and investors of this industry must constantly monitor it so that they can determine its growth. This research aims to closely monitor this industry to create guidelines for all the people... 

Many theoretical and empirical studies in finance explicitly or implicitly rely on the Gaussian distribution assumption for the variables under consideration. This assumption is applied in various ways, from its use as the basis for deriving the optimal portfolio composition in the classical Markowitz framework to statistical tests assessing the significance of different variables effects in various regressions. Despite extensive empirical evidence supporting the non-Gaussian distribution of returns in stock markets, there is still a gap in achieving a comprehensive model to replace the Gaussian assumption across all areas of financial studies. In this study, alpha-stable distributions are... 

The amount of fresh water suitable for various uses is decreasing day by day. This may be due to evaporation or contamination of water or such. Heavy metal cations, dyes, oils and solvents are the most important substances that contaminate water. There are various ways to remove these contaminants, one of which is the absorption of these substances by suitable absorbents. Carbon compounds have attracted much attention among all the absorbents used so far. The aim of this study is to produce carbon aerogels from an economic and modify its structure and properties by adding graphene nanosheets. In this study, Novalak-graphene oxide (GO) gel was fabricated using solvent-saturated vapor...