Sharif Digital Repository

Nowadays, Information Security is one of the most challenging issues in organizations. With the development of technology and the Internet, people insist on greater access to information and data. In addition to creating value-added for the organization, collecting a huge amount of data in the organization's database and using IT tools threat it by losing the funds and credibility obtained from customer confidence in different ways. Therefore, managing information security is necessary due to the current competitive environment. In spite of the advancement of technology, the existence of many complexities in this subject led to the growth of security incidents. Hence, the organizations’... 

Defending software against different types of attacks is challenging enough, but for server-side programs it is even harder. The ever-changing nature of technologies used on server-side programs makes it more complex. In this thesis we try to identify these challenges in regard to two specific technologies: multi-service architectures and asynchronous I/O. Then, we present a new framework for running software in asynchronous multi-service architectures with native support for access control rules. Our framework acts as an intermediate between services and can support rules based on the distributed request context that exists between services.
 

The objective of this thesis is to prioritize a portfolio of buildings for seismic retrofit. A new set of sensitivity measures is proposed to rank the buildings in accordance with the reduction in the loss of the entire portfolio. To this end, various risk measures are differentiated with respect to the cost of retrofit for each building. These risk measures are the moments of the portfolio cost probability distribution which imply the risk-neutral and risk-averse decision making. Two costs are considered: Construction cost due to retrofit and repair cost due to structural and non-structural damage. To quantify the risk, reliability methods are employed in which many interacting... 

Optical impairments, as a challenging obstacle in optical communication systems, have been under deep attention of optical engineers in recent years. These impairments can be divided into two categories of linear and nonlinear impairments. Dispersion is a significant linear impairment leads to broadening of the optical signal and interference between transmitted symbols during detection. Nonlinear impairments such as cross-phase modulation (XPM) and self-phase modulation (SPM) also distort the transmitted signal through the fiber, causing interference at the receiver and degrading the system's performance. An appropriate solution for compensating optical fiber impairments is to utilize... 

Earthquake is one of the deadliest natural hazards that has taken more than 400 thousand lives, only in the last decade. Iran is one of the countries that are at high risk of potential death toll resulting from such hazards, firstly because it is located in a potentially high-risk zone, the so-called earthquake belt and, secondly because of its problems in the management of disastrous situations (especially, pre-disaster management). Bam 2003 earthquake is one of the most painful experiences in this context. So, in this research, emphasizing on the practical use of optimization models, an existing model is applied on the damaged area of the Bam earthquake. The mentioned model considers the... 

Scientific studies, conducted over the world, show that an immense portion of pollutants and greenhouse gases emission to the atmosphere are the direct result of the incineration of fossil fuels in industrial units. These industrial units include chemical industries, power plants, metal industry, etc. Therefore, there is a tremendous necessity to reduce the pollutants emission from these industries immediately and effectively. Meanwhile, in order to mitigate the emission to the atmosphere, there should be a meticulous estimation of pollutants emission from various sources. Hence, in a project called "standardization of emission of pollutants from diverse industrial units in Iran", the... 

Oil and gas industries are always considered as one of the most polluting industries in the world. Many pollutants are emitted from the industry into the environment every year. Equipment’s leak and flaring off additional gases produced by various processes of oil and gas production are the main sources of waste in these industries. In order to control these hazardous wastes, it is necessary to provide effective solutions and make appropriate decisions so policymakers will be able to implement policies in order to reduce the emissions of air pollutants. In order to reduce the emissions, it is necessary to conduct the correct and reliable methods and have sufficient information about the... 

Due to the physical limitations of the conventional 2D ICs at Giga-Scale Integration, modern technologies have been emerged. Among them, through silicon via (TSV) - based 3D ICs have been used to continue Moore’s law in the interconnect era. In these systems, dies are stacked at z-direction after wafer thinning. Electrical connections between stacked dies are done by TSVs. One important advantage of 3D integration technology is their ability to stack heterogeneous systems with different technologies on a single chip. This will not only increase interconnect density but also will reduce the delay and power consumption. However, nowadays, fabrication and optimum design of TSVs are still big... 

Annually Natural disasters make tremendous impacts on societies. Fatality rate of earthquake in Iran is almost more than all other disasters. There are numerous problems in disaster Management's of Iran and other countries. One of the disaster Management's phases is response phase which mostly depends on emergency processes, so most of papers working on this phase, plan for emergency state by using different techniques.All the studies seeking the response phase, try to reduce the loss of disaster by the use of immediate response to earthquake, pointing the disaster after occurrence. But Another point of view is to make loss reduction by precautious activities and plans. Actually, the loss... 

Use of nano-scale VLSI technologies in the fabrication of System-on-Chips (SoCs) makes reliability as one of the major issues in the design and implementation of these products. SoCs are susceptible to several fault sources such as crosstalks, cosmic particle strikes, electromagnetic interferences, and power supply disturbances. Among the mentioned fault sources, crosstalks have the major contribution in threatening the reliability of SoCs. This thesis addresses the modeling and mitigation of crosstalk faults. In this regard, two analytical models and three crosstalk reduction methods have been introduced. The proposed analytical models, which have been introduced in the fourth chapter of... 

Today, considering the global demand for reducing greenhouse gas emissions, rechargeable batteries are considered as a source of energy in electric vehicles, hybrid electric vehicles and smart grids. In all these applications for secondary batteries, the battery management system requires an accurate estimate state of charge of each cell. However, this estimate is difficult particularly for battery aging. In this study, a lithium-ion battery is modeled by using multidimensional multiphysics modeling and simulated in a comsol. In this simulation, the effect of the thermal conductivity coefficient on the battery temperature, initial salt concentration in electrolyte and the rate of discharge... 

The purpose of study is the modeling and evaluation of the role of authorities in enhancing the effectiveness of seismic vulnerability reduction policies. Seismic vulnerability reduction of infrastructures depends on the measures that must be taken before a disaster occurrence. In addition to increasing disaster preparedness, an important part of the pre-disaster measures is taken to increase the robustness of the infrastructure. In some cases, measures to reduce the vulnerability of infrastructure, such as the resilience of residential buildings, require the coordinated role’s implementation of relevant organizations. Evidence shows that in many cases, policies to reduce the vulnerability... 

The release of toxic materials causes tragic accidents every year. There are various techniques in order to mitigate the release effect of these materials such as Application of air jets, steam curtains and water curtains. In this study first, previous works are reviewed in order to select the best technique for the mitigation of heavy toxic gas release. Then CFD modeling is used to simulate this technique.
A field situation in which chlorine gas was released upwind of water spray was simulated using the open-source software FDS (Fire Dynamic Simulator), a CFD model. Only mechanical effects of water sprays are considered; hence the effect of absorbtion is neglected. Finally tha... 

The release of toxic materials causes tragic accidents every year. There are various techniques in order to mitigate the release effect of these materials such as Application of air jets, steam curtains and water curtains. This study presents numerical calculations to reproduce the continuous ammonia release dispersion with and without the mitigating influence of a downwind water curtain using computational fluid dynamic (CFD) software ANSYS Fluent 15.0. The RNG model coupled with Lagrangian discrete phase model (DPM) was used to simulate the dilution effectiveness of the water curtain system. The ammonia absorption was taken into account by means of user-defined functions (UDF). The... 

Evaporative cooling systems are of most common cooling systems which their electricity consumption is much lower than vapor compression cooling systems. Enhancement of these system’s performance could help to propagate these systems and also decrease the electricity consumption and corresponding emissions in large scale. In this thesis, first a modified cycle is proposed for evaporative cooling. Then, in order to use evaporative cooling in humid climates, a desiccant wheel is implemented in this modified evaporative cooler. As using evaporative cooling will cause high water consumption, a novel cycle is proposed for desiccant based evaporative cooling which is able to cover system water... 

Carbon dioxide is one of the main geenhouse gases emitted from factories as well as transportation vehicles that adversely affect the atmosphere and cause global warming. Among the proposed solutions to reduce carbon dioxide in the atmosphere, carbon dioxide separation would be the most viable medium-term approach. However, the high cost of carbon dioxide separation prevents the development of carbon dioxide absorption technologies. Therefore, it seems that integrating separation and production processes is the most efficient way to save energy and reduce carbon emissions. This method decrease a high proportion of the energy consumption in upstream operations (carbon dioxide removal,... 

Expansion of using social networks for reading and sharing news on the one hand, allows for quick and easy access to the news, but on the other hand, increases the spread of fake news and misleads many users. Therefore, identifying the fake news and attempting to mitigate its spreading on social networks is one of the major research areas in recent years. An important issue in this regard is reducing the time gap between news release time and identifying it as fake and starting to take action. Many researches has been done on detection of fake news, but since there is a trade-off between minimizing the time gap and maximizing accuracy, work on these models continues. There are also different... 

Climate change and energy security are key drivers for future energy policy. While energy security has been a pillar of energy policy for about a century, concern about climate change is more recent and is bound to radically change the landscape of energy policy. Policy makers are now under increasing pressure to address these twin challenges: to develop cost-effective policies that will both ensure the security of our energy system and reduce greenhouse gas emissions.
Main Effort in this Project is to construct an integrated model of Iran’s energy system to serve as a policy analysis tool, by which policymakers are able to identify the future effects of a wide range of policies in... 

The power control of horizontal axis wind turbines can affect significantly the vibration loads and fatigue life of the tower and the blades. In this thesis, we are going to consider both the power control and vibration load mitigation of the tower fore-aft vibration. For this purpose, at first, we developed a fully coupled model of the NREL 5MW turbine. This model considers the full aeroelastic behavior of the blades and tower and is validated by experiment results, comparing the time history data with the FAST (Fatigue, Aerodynamics, Structures, and Turbulence ) code which is developed by NREL (National Renewable Energy Lab in the United States). In the next, to estimate EWV, a novel... 

The transportation and electricity industries are major emitters of greenhouse gases (GHGs). In order to reduce emissions, several strategies have been proposed, including plug-in electric vehicle (PEV) use and integration of renewable energy sources (RESs). To reduce the concern emission rate while considering economic constraints, it is important to examine different scenarios of incorporating these elements. To investigate the effectiveness of using PEVs and RES from various perspectives, this study utilizes a combined economic emission dispatch (CEED). The influence of emission and cost coefficients is examined in a sensitivity analysis. In the proposed model, two test cases containing...