Sharif Digital Repository

Ramp merges are among high potential congested sections of freeways. On-ramp driver behaviors are often complicated. Traffic models for freeway merges are often based on gap acceptance theory and lane changing models. Gap acceptance theory states that drivers merging from on-ramp to freeway, seek acceptable gaps to merge into freeway. Both lead and lag gaps should be acceptable for a driver to merge to freeway.
In this research, drivers’ behavior in two on-ramps of Tehran city was studied. After field data collection using camera, data were extracted from films. First, distribution of time headways in freeway right lane and gaps between merging vehicle with lead and lag vehicles were... 

This study wants to analyze the effects of the banking system on the transmission of monetary policy and its impact on wealth inequality. We use a continuous time heterogeneous framework with heterogeneity for households and capital producers. The model is an extended version of a two-asset heterogeneous agent New Keynesian model with heterogeneous capital producers and a bank with liquidity transformation. The production block consists of a final-good producer, intermediate-good producers, and capital-good producers. Capital good producers could get loans from the bank but have a borrowing constraint. We found that a) an expansionary monetary policy increases the issued loans, which leads... 

Due to the global crisis of water and energy scarcity, the design and optimization of water treatment systems with the aim of reducing energy consumption and increasing efficiency have gained significant importance. An electrodialysis system was simulated and validated using advanced lumped model, considering all critical effects in the process, such as Donnan resistance, boundary layer resistance, and osmotic and electroosmotic flows, across salinity ranges from 0.35 to 200 parts per thousand. Additionally, a reverse osmosis desalination system was simulated and validated using the solution-diffusion model, with the concentration polarization coefficient calculated via the thin-film theory.... 

Interaction of vortices with particles is one of the complex and fascinating phenomena in fluid dynamics, which is often observed in wind turbines operating in dusty environments. In these turbines, dynamic stall occurs where vortices continuously form and dissipate. In this study, the impact of the presence of dust particles on dynamic stall, which can noticeably affect the aerodynamic efficiency of wind turbines, has been examined and analyzed; We focus on three airfoil models of the horizontal-axis wind turbines. namely S809, S822, and SD7062 at a Reynolds number of 10^6. These were examined using numerical simulation, with k-ω SST turbulence model and discrete phase model (DPM). The... 

Nowadays, extensive use of Hardware Trojan Horses (HTH) or backdoors is more prevalent than ever. We could count disruption, disabling, eavesdropping and sending out internal information as misuse.
In this project, we embed hardware trojan in a Programmable Logic Controller, and present different methods to detect and neutralize them. This is an important issue, as PLCs should work in a safe environment especially in industrial environments while keeping the information intact is significant as even a slight intentional malfunction could cause data to be lost or disclosed, and result in a catastrophe. Subsequently, features of hardware of PLCs should be examined and the right place of... 

Through the last decades, due to environmental issues and to confine CO2 emission and also dependency to the fossil fuels, renewable energy resources has been developed. It’s been expected up to 2035, the renewable energy resources will be scaled three times and among those resources, the wind energy will stand prominently. Out of this king of renewable resource, the horizontal wind turbine has been subjected in this research. The focus of is to design the controller in third of a 2 MW turbine operation by which stable rotor speed and nominal output power to be attained. Besides, to enhance the accuracy of the wind turbine profiles, the TURBSIM software (At the National Renewable Energy... 

Through the last decades, due to environmental issues and to confine CO2 emission and also dependency to the fossil fuels, renewable energy resources has been developed. It’s been expected up to 2035, the renewable energy resources will be scaled three times and among those resources, the wind energy will stand prominently. Out of this king of renewable resource, the horizontal wind turbine has been subjected in this research.The focus of is to design the controller in third of a 2 MW turbine operation by which stable rotor speed and nominal output power to be attained. Besides, to enhance the accuracy of the windturbine profiles, the TURBSIM software (At the National Renewable Energy... 

In recent years, having an efficient supply chain has become an important element in the success of organizations. Attention to different aspects of the supply chain can have a significant impact on gaining a competitive advantage in the market. With the development of global markets, designing resilient supply chains has become a critical issue among businesses. The importance of this topic has prompted researchers and decision-makers to develop quantitative and qualitative models to reduce the damages caused by disruptions to supply chain systems. Various factors, including human and natural elements, can jeopardize the efficiency of supply chain systems. Therefore, supply chain systems... 

Over the last years, terrorist attacks and accidental explosions have brought on a need for research in the field of structural engineering to study the response of a building subjected to blast loading conditions. An explosion within or surrounding a building, not only can have disastrous effects causing both structural damage or failure, but may also lead to the death of human beings.In order to prevent these catastrophes and gain a better understanding of responses of the buildings and lateral resisting systems with different characteristics, the study of the behavior of the lateral resisting systems under blast loading conditions is essential. This research will also aid in the... 

Concentrated photovoltaic systems (CPVs) allow simultaneous production of electrical energy and high-temperature thermal energy. These systems consist of a concentrator for collecting solar rays onto the surface of the recipient cells. Moreover, these systems are always facing the sun using a sun tracker. The heat generated by these systems can be used in industrial processes, heating, cooling, and water desalinating. Given the concurrent generation of power and high-temperature heat, it is possible to achieve higher efficiency than that of conventional solar systems. Furthermore, the electrical efficiency is also higher than conventional systems due to the use of multi-junction solar cells... 

The main factor ensuring safety of passing maneuvers on two lane highways is known as Passing Sight Distance (PSD). The criteria presented in Iran's code and AASHTO Green book are provided by the results of researches conducted between years 1938 & 1941 in the United States. This research intends to find out whether some changes should be applied to the PSD criteria according to current vehicles' performance and driving behavior in Iran. For this purpose, about 8 hours of video films has been recorded from 3 different sites chosen from two-lane highways in Iran, resulted in 326 passing records. In the case of passing of two passenger cars The models provided by analyzing the videos show that... 

Frontage roads are widely used to separate the main and the local traffic flows in multilane highways. Based on the studies conducted by Texas Transportation Institute, the delay imposed by ramp junction is considered for calculating the average speed in frontage roads in addition to the control delay caused by traffic lights. This delay and the capacity of frontage roads are analysed using gap acceptance theory. In this study, two different sections consisting of a basic section and merge area are selected along Tehran-Karaj special road as case studies and the required data are collected by video recording. After classifying and analysing the data, a wide range of macro traffic-analyses...