Sharif Digital Repository

Airport Traffic Control Towers (ATCTs) are among the most critical structures in an airport that are expected to keep their level of serviceability after severe strong earthquakes. Therefore analysis and design of these structures need a detailed investigation on the seismic behavior of the structure based on the structural characteristics. In this study three different existing reinforced concrete ATCTs have been investigated. As important parameters of earthquake design of structures, response modification factor (R-factor) of these towers will be determined. R-factor reduces elastic force level to design force level and contains the effect of ductility, overstrength. In Iranian seismic... 

Nowadays, prolific usage of free air as a medium for data transmission leads interests to optimize the conditions of devices which are involved in wireless communication systems. Inter-Symbol Interference (ISI) distortion is a natural characteristic of wireless channels that occurs due to propagating electromagnetic waves in different directions. Due to different paths between a transmitter and a receiver, the received signal consists of several copies of the transmitted signal with different delays. The most common way of eliminating or mitigating the effects of ISI is channel equalization. The present work leads to implementing a supervised equalization in wireless communication. The... 

Controlling the nonlinear processes is very important in industry. In this thesis, model predictive control is considered as a nonlinear control strategy and two nonlinear models, namely wiener and Hammerstein models are used and their identification methods are described. State-space model is also considered and closed-loop stability has been studied. Another strategy for controlling the nonlinear process is global linearization control. Some concepts and related theorems for this strategy are stated. PID controller is used as a linear controller for this strategy. In this model for estimating the state and load, two nonlinear observers are used. Stability analysis of output feedback... 

Recent violation of security properties of e-voting protocols not using provable security, indicates the importance of provable security. In this thesis, we use the provable security approach to analyze security properties of e-voting protocols.In addition to presenting an efficient and provably secure protocol, the minimal assumptions to achieve privacyin e-voting protocols are analyzed. The firstcon-tribution of this thesis is presenting an efficient and provably secure coercion-resistant protocol, which is a variant of the JCJ e-voting protocol (Juels et al.,2010). It decreases the total number of JCJ’s operations fromO(n2) to O(n). The second contribution of this thesis is proving the... 

In most of the engineering applications, the mechanical behavior of materials in high strain rate deformations differs from their behavior in quasi-static deformations. In some engineering problems like impact loading on structures, metal forming and explosive forming, the range of strain rate is about . Taylor impact test is one of the experiments used for characterizing the dynamic behavior of materials in high strain rate deformations. In the Taylor impact test a rigid cylindrical projectile is impacted normally onto a hard and massive surface (anvil), the projectile deforms by mushrooming at the impact end. With plastic wave propagation analysis, the plastic deformation of projectile is... 

Safety is an important factor in the nuclear power plants due to its inherent human and environmental hazards. Therefore, in order to ensure the safety of the plant and proper functioning of its various components, a series of commissioning tests should be conducted according to international nuclear power plants standards, before its operational exploitation. On the other hand, safety of the plant can be guaranteed by modeling transient states and possible scenarios of accidents in different situations. In this study, a commissioning test of Bushehr Nuclear Power Plant (BNPP) and its associated accident is modelled by gathering geometric data and information about the facilities... 

With the growth of the population and the significant expansion of industries in the last century, many environmental problems have plagued developed and developing countries. One of these environmental problems is water pollution. Observing the effects of water pollution over time, sanitary and industrial wastewater treatment was proposed as a reliable solution. With technology development, wastewater treatment requirements have become stricter. The increase in energy consumption and wastewater treatment costs due to population growth and industrialization on the one hand and strict regulations, on the other hand, have forced those involved in this field to employ a variety of technical and... 

The air distribution is the main factor of contaminant transportation in cleanrooms. The experimental method is the most reliable one for investigation of flow field, which the difficulties associated with it, has limited not only the examination of the flow field in cleanrooms, but also the improvement of their qualities. Most of the experimental researches in indoor air quality concern conventional rooms and do not take into account specific supply-exhaust diffuser configurations, which are used in cleanrooms. Using small-scale models can reduce the complexity and the cost of measurements. In this research, the 3D velocity field of a small-scale cleanroom is measured in three different... 

The main aim of this study is developing a robust QSAR model for describing and predicting the inhibitory activities of O-(2-phthalimidoethyl)-N-substituted thiocarbamates derivatives as novel HIV-1 non-nucleoside reverse transcriptase (HIV-1 NNRTIs) inhibitors. These drugs change the active site of the reverse transcriptase enzyme, and finally halter the HIV reproduction cycle. As the first step of this study, a multiple linear regression (MLR) model was built but it has no satisfied prediction ability. As a next step, the nonlinear correlation of the molecular descriptors and activities has been investigated by using artificial neural networks (ANN). In this section the effects of variable... 

Life insurance is a contract whereby the insurer becomes insured under certain conditions and for an amount known as insurance premium. Consequently, the insurer will pay the insured inheritors some given benefit as in the contract. There are different types of life insurance in the market. Other sectors of our proposed portfolio include risky and risk free investments. Household consumption is also considered as another variable in this package. This problem can be raised in both inflationary and non-inflationary states. You can also include a variable called loan. In the literature, this problem has been addressed by considering a sub-category of life insurance (Term Life Insurance)... 

Cloud infrastructure pricing framework is one of the challenges for many cloud economists and researchers, albeit its proper definition is one of the main requirements for business triumph. Efforts to focus on this issue have been extensively focused on a uniform market. Moreover, the models are mainly based on the cost factor and resources of cloud infrastructure, aiming to maximize revenue and profit margins for cloud service providers. Models that also consider the demand side and define criteria regarding the customer needs, preferences, and experiences are called value-based models, which provide a great competitive advantage for the providers aside from its higher profit margin and... 

This thesis presents a resonant time-periodic structure based on the Fabry-Perot resonator for frequency comb generation. Time-periodic structures cannot generate a frequency comb by themselves because side-harmonic amplitudes are really weak. However, due to resonant structure, it is expected that the side-harmonics, which are generated because of the time-periodic part of the structure, are increased if they are close to the main modes of the structure. But the results show that, generally, the amplitude of side harmonics, which are close to the main mode, is increased and far side-harmonics don't have remarkable amplitudes. However, we will show that if the modulation frequency of the... 

In this thesis, combustion of liquid fuel spray under the condition of hot and diluted oxidizer, has been investigated. To this end, a novel type laboratory-scale test rig was designed to study the physics governing the MILD-Spray combustion conditions with an applied approach. The underlined test rig eliminates the operational problems of its predecessor test stands and is used for a heavier fuel with much more complex chemical composition (kerosene). The test section is axially symmetrical, in which the fuel is injected by a pressure-swirl atomizer in the direction of hot and diluted co-flowing air. With the use of the aforesaid test rig, the effect of variables such as oxygen...