Sharif Digital Repository

Observations of cosmic microwave background (CMB) and large scale structure show that standard model of cosmology ΛCDM is consistant with observational data. The standard model is defined by cold dark matter, cosmological constant and also Gaussian inital conditions which are almost scale-invariant, adiabatic and isotropic.while this model is consistant with observational data, there exist a couple of problems namely the problems of dark energy, dark matter, missing baryon and early universe. One of the most recent methods to analyse cosmological models which is tightly ascociated with structure formation is the use of galaxy clusters distribution function and the effect of such structures... 

The light emitting diodes is composed of an electron transport layer and hole transport layer. The electrons and holes go to the middle region called active region through these transmit regions, and they emit light from themselves by recombination in this area. In our structure, the active region consists of quantum dots. The emitted light characteristics depend on these dots to great extent. In this thesis, we first describe the processes in this type of device, and then we will review the well-known structures that have been reported so far. In chapter 4 discusses the important characteristics of the active region, including the size of the quantum dots and the wetting layer, and we... 

In this study, we simulated and analyzed a plasmonic waveguide modulator based on single layer graphene. It includes a graphene sheet, which sandwiches between two layers of silicon dioxide. Then, some gates are arranged on either side of the waveguide on a periodic structure. When an electric field is applied perpendicular to the waveguide plate, the Fermi level of graphene under the gates, changes. Detailed analysis is performed by the method of lines based on Maxwell's equations along the propagation direction of the waveguide. Computation of the multi-gate device starts by examining the effect of Fermi level. Transmission coefficient of the magnetic-field norms of the modulator is... 

In the present thesis, the SPASER is investigated, from theory to structure design. SPASER is a counterpart of laser in 3D subwavelength dimentions. In other words, SPASER does not suffer from the diffraction limit of photons which is a drawback in laser technology. It potentially can generate intense coherent dark and bright surface plasmon modes. The small size of SPASER gives it the capability of being integrated with electronic chips. So, the electronic technology will become faster if the SPASER is realized. In this thesis, we intend to use the unique plasmonic properties of graphene in our designs. Plasmons on graphene platforms have longer propagation length and larger lifetime in... 

According to prediction of ITRS, power consumption and bandwidth of processors' interconnection, will be the most major bottleneck of the System-on- Chips (SoCs) in the future. Therefore, in MultiProcessor System-on-Chip (MPSoC) architectures, the design constraints will be altered from "Computational Constraints" to "Communicational Constraints". There are three kinds of communications in the surface of the chip: Global, median and local. The main difference between global and local connections is that the length of latter one will be changed with technology. In other words, it is scalable like processor's elements while the length of global connections is practically constant. Even though... 

Opportunities for creating value are shifting from managing tangible assets to managing knowledge based strategies that deploy on organizations' tangible assets: customer relationship, innovative products and services, high quality, and responsive operation processes, information technology and databases and employee capability skills and innovation" (Strategy Focused Organization, Norton, Kaplan; 1996). As organizations' value creating process shifts, learning has become one of the most important factors in value creation, and as a consequence dynamic capabilities creation. This research is concentrated on Electric Distribution Companies in Tehran region and studies knowledge management as... 

Nowadays competition in business world has increased drastically. Under these competitive circumstances, it is the supply chains that compete against each other rather than individual firms. Accordingly trying to achieve integrated and synchronized management of activities within a supply chain has become inevitable. Recently researchers have found interest in a particular problem in a supply chain and that is to minimize inventory and routing costs in a supply chain. This problem is known as Inventory Routing Problem (IRP) and has been intensely examined in past few years. In this thesis we will try to expand this well-known problem in pricing dimension. We call this new problem “Inventory... 

Human body is subjected to body accelerations or vibrations in several circumstances. During gravitational changes, the hydrostatic pressure gradient along the body axis changes, and then body fluids are redistributed. Prolonged exposure to high level external acceleration may lead to serious or even fatal situations on account of disturbances in blood flow. Due to physiological importance of body acceleration many theoretical investigations have been carried out for the flow of blood under the influence of body acceleration. In this study, the mechanical loads that pilots experience during flight are considered. The aim of the present study is to investigate the effects of mechanical... 

Master curves describe the behavior of asphalt binders over a wide range of temperatures and loading frequencies which are utilized by various predictive models in design and analysis procedure of asphalt mixtures. Frequency sweep test is extensively used for construction of master curves within the temperature range of 4 ̊C to 82◦̊C and frequency range of 0.01 to 30 Hz. There is a concern that master curves are unable to accurately represent the low temperature (below 4 C) behavior of binders. In this study a new cyclic loading pattern for the bending beam rheometer (BBR) test was utilized to conduct the low temperature tests and generate an isotherm compliance curve for incorporating the... 

IoT security is an important step in the rapid development of its applications and ser-vices. Many security protocols have been defined to maintain security at higher communication layers, such as the transport layer and the application layer, but with the advent of quantum computers due to high-speed parallel computing, the previous methods are no longer secure and we have to establish security at lower layers such as the physical layer. The efficiency of IoT devices depends on the reliability of their message transmission. Cyber-attacks such as data injection, eavesdropping and man-in-the-middle can lead to security challenges. In this study, we propose a new deep learning based component... 

It is undeniable that there is a great disagreement in the every field of religion. Reductionists argue that awareness of disagreements reduces the justification and rationality of beliefs, including religious beliefs. In contrast, non-reductionists believe that while reductionism may be true in other domains, it is not necessarily true in religion, because religious beliefs have characteristics that can deny a reductionist argument. They are in the realm of religion. In this thesis, I will discuss issues related to those characteristics that can deny reductionist argument in the realm of religion. In this thesis, I try to show that the arguments and responses presented in defense of the... 

The purpose of this research is to introduce a heterostructure for Vertical Tunneling Field-Effect Transitors, calculating its band structure and finding the tight binding hopping parameters of its structure. To do this, we must first study different kinds of heterostructures and choose the most suitable one among them. In this research, we selected the three-layer graphene eSoM2-BN-Gr_h for its high on/off current ratio (〖10〗^6). To find the band structure, first we should construct unit cell and then find its crystal structure after relaxation. The lattice constant for graphene and is the same, but the lattice constant of graphene andeSoM2-BN-Gr_h is different . The number of atoms in the... 

Although, planning and control systems improved, but most of projects have some Problems such as long time and high cost. In project oriented organizations which Perform several projects have more problems. An important reason of these Problems is lack of skill and competency of executive factors and project managers In planning and control. These persons are chosen base on organization Relationship, not systematically. One way to become successful in projects is Chose and assessment of project managers and executes in right way. "System of Competency and assessment of project manager" is offered to solve this problem. According to this system, at first projects are defined and grouped base... 

Today, the major part of the capital of each country, especially developing countries, is devoted to its construction and construction projects. On the other hand, one of the growth and economic factors of any society is the success of its development projects. In fact, one of the activities of developing countries to build economic infrastructure is the implementation of infrastructure development projects that account for the bulk of the country's budget annually, and therefore the principled planning of these projects is from the requirements and it is necessary to achieve the lowest cost-to-productivity ratio. In Iran, which is considered as a developing country, a significant amount is...