Sharif Digital Repository

The objective of this research is to develop a mathematical model for analysis and design of airport cities. In this model, the interactions among the elements of an airport city -regarded as a complex system- will be analyzed, and the impact of the stakeholders’ requirements on the functional and physical architecture of the airport city will be investigated. So as the first step, the stakeholders of the system and their requirements are identified and classified. Second, the concept of operation of the airport city is investigated, and then the architecture of the system is modeled as a queuing network. So that each element of the airport city is regarded as a service center, including the... 

Nowadays, improved laser technologies and ultra-short pulse generation yield Ion and proton accelerations through laser-plasma interaction that has attracted great interest among researchers. Laser-induced particle beam acceleration establishes unique features compared to previous traditional methods that make them an attractive research field. Interacting high-power lasers with a dense matter or plasmas would generate an electrostatic field up to a few TV/m that is suitable to provide accelerated ion beams even up to few tens of GeV within a small micrometer volume. While the accelerated ion beams possess outstanding features, challenges such as increasing ion energies, spatial-spectral... 

Named Entity Recognition (NER) is one of the most important tasks in natural language processing. Improving performance in this task benefits other tasks. However, with the rapid expansion of text volume and diversity, significant challenges have emerged in this area. This thesis proposes a model to address the problem of multi-domain Named Entity Recognition. Traditional approaches used for multi-domain NER often have considerable limitations. Training a single model for diverse domains does not yield optimal results, while using multiple large models can lead to resource constraints. Additionally, approaches based on generative models for non-English languages, such as Persian, which is... 

US 2008 financial crisis, spread across the international stock markets in the second half of the year 2008. The crisis decreased the returns and increased the volatilities of almost all of the stock indices, however, its effects on Iran’s stock markets were unexplored. Financial limitations create an exclusive situation in Iran’s stock market. Using weekly data on the stock indices from July 2006 through August 2009, this study aims to exam in the contagion effects of the global financial crisis through the main indices such as S&P500 and FTSE100 on Tehran Stock Exchange indices: industrial and financial intermediary indices and The First and the Second indices of Tehran’s Stock Exchange.... 

First, we review in an appropriate way the researches regarding building blocks of a wireless network (Shannon channel, multiple access channel, broadcast channel, interference channel, relay channel) and then: • We consider two cases for a relay and describe the essential role of the relay with three Markovity conditions; define Almost General Relay Channel with Decode-And-Forward (AGRCDAF) strategy and determine its capacity. Then, we prove that our capacity theorem not only includes all known capacity theorems as its special cases but also potentially is applicable to other relay channels and is validated by its consistency with previous results related to special cases of broadcast and... 

Due to the development of heat pipes in different industries and special characteristics of heat pipes, in this study, it has been tried using computational fluid dynamics (CFD) method to simulate a heat pipe heat exchanger that can be a replacement for the normal radiator. The experimental model of this heat exchanger has been tested at past studies and the numerical simulation of the heat exchanger will analyze at present study. The use of heat pipe in the car radiator has many advantages such as reducing fluid pressure drop through the heat exchanger, high reliability due to the particular structure of the heat exchanger (individual performance of each heat pipe) and improving heat... 

The research focused on developing polyvinylidene fluoride (PVDF) nanocomposites with enhanced piezoelectric and mechanical properties. To achieve this, barium titanate nanoplatelets (BTNPs) were incorporated at varying weight percentages into a PVDF matrix. Fused Deposition Modeling (FDM) 3D printing was employed to control nanoplatelets' orientation, aiming to improve properties. Initially, BTNPs were synthesized using the hydrothermal technique and homogeneously dispersed in a PVDF matrix with an internal mixer. Nanocomposite samples were fabricated using compression molding and analyzed with X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning... 

Land subsidence is a gradual settling or sudden sinking of the land surface from changes that take place underground. There are different causes of land subsidence; most notably, groundwater overdraft and severe weather conditions. Subsidence of the land surface due to ground water overdraft is caused by an increase in the intergranular pressure in unconsolidated aquifers, which results in a loss of buoyancy of solid particles in the zone dewatered by the falling water table and accordingly compaction of the aquifer. In this study, an experimental approach was developed to examine applicability of Microbially induced carbonate precipitation (MICP) for land subsidence control under...