Sharif Digital Repository

One of the most widely discussed parameters in energy economics is the price elasticity of gasoline demand due to its substantial implications for taxation, energy efficiency, and environmental policies. This paper aims to estimate the price elasticity of gasoline demand using a novel source of data. The data is from Iran, in the early months of 2014. Vehicles get a quota of 60 liters per month as subsidized gasoline at a lower price. The quota is transferable to the next months if it has not been consumed. All of the information about each pumping transaction is gathered in a centralized database, assigning a unique fuel card to each vehicle. Consequently, the structure of the market provides... 

The process of gas injection is well-known for Enhanced Oil Recovery (EOR) among researchers in the past few decades. This process depends on both compositional effects and IFT reduction effects as the conditions approach miscibility. This study seeks to evaluate the interactions of these two fundamental mechanisms in the process of enriched gas injection for EOR. At first, we investigate the relative dominance of the key mechanisms, as well as composition paths, component and phase distribution, and component production via compositional simulation of the process of gas injection into 1D homogeneous porous media such as slim tube and core under immiscible and near-miscible conditions. Then,... 

Membership inference attacks are one of the most important privacy-violating attacks in machine learning, as well as infrastructure of more serious attacks such as data extraction attacks. Since membership inference attack is used as a measure to evaluate the level of privacy protection of machine learning models, different researches have investigated and provided new methods for this attack. However, the accuracy of these attacks has not been investigated on models trained with the latest techniques such as data augmentation and regularization techniques. In this research, we see that the Lira attack, the latest membership inference attack, which has much more power compared to previous... 

Soil-structure interaction has significant effect on dynamic behavior of the super structure. This effect is usually investigated in two separate parts, i.e., the Kinematic Interaction effect and the Inertial Interaction effect. The first modifies the input ground motion to the foundation as a result of difference in soil and foundation stiffness. The later, i.e., the II effect, introduces the effect of soil flexibility and radiation of waves into the supporting medium on the response of the structure. These effects are usually considered by introducing a replacement oscillator with modified natural period and damping ratio subjected... 

Proteins are of fundamental importance for life on Earth and participate in virtually every process within cells. The function of a protein depends on its three dimensional structure. If this is disrupted, the protein loses its biological activity. In addition to temperature, pressure and ionic strength, pH is also an important factor that affects the configuration of proteins. Proteins contain acidic and basic residues. Variations in pH lead to changes in distribution of atomic charge, which in turn affect the stability and function of proteins. Protein folding occurs in a specific pH range, a deviation from which may facilitate misfolding or Amyloid aggregation. It is therefore necessary... 

Nanosized CdS coupled TiO2 nanocrystals were prepared by a microemulsion-mediated Hydrothermal method at relatively low temperatures. Modification of this nanocomposite with Tyrosine,Phenylalanine,Glysine and Glutamate ,especially Tyrosine resulted in enhanced photocatalytic degradation rate of Nitrobenzene( NB ) compared to using CdS-TiO2 under visible light irradiation. The prepared samples were characterized by BET,SEM, XRD, UV–Vis spectroscopy ,FTIR .It was found which have high surface area about 470 m2 g−1 and mesoporous character with the average pore diameter of 2.8 nm.The results showed this nanocomposite consisted of uniform anatase TiO2 with highly dispersed cubic phase CdS... 

Adaptive beamforming performance is very sensitive to any mismatch between actual and presumed steering vectors of desired signal. In addition to this sensitivity, presence of desired signal in training snapshots dramatically reduces the convergence rate, as compared to the case that signal-free training snapshots are available.
The present work is aimed at proposing a new adaptive beamformer that is robust against direction-of-arrival (DOA) mismatch and has high convergence rate. This method is based on desired signal elimination from training snapshots and sub-array beamforming technique. To this end, a Blocking matrix that converts primary data to desired signal free data is... 

The water level of Lake Urmia has experienced a drop of 7.83 meters, from 1995 to 2017. According to previous studies, the uncontrolled development of agriculture, high consumption cultivation pattern, overuse of water resources for agricultural use and high water loss due to low irrigation efficiency, are the most important factors in the drying of Lake Urmia. Since agricultural sector is the largest water consumer (approximately 90%), the Lake Urmia Restoration Program has decided to study and implement the 40% reduction of water consumption in agricultural sector plans.Due to the inherent complexity of the Urmia Lake basin, accurate and realistic evaluation of the effectiveness of the... 

In this research with Finite Element Method in ABAQUS, a Number of Numerical modeling has done in two-dimensions, which can be used to determic the effect of different factors on the seismic vulnerability of tunnels. Also, varios factor such as Geotechnical conditions, tunnel depth, tunnel thickness and ground water is considered in this study.One of the parameters considered in designing tunnels is the ability of the tunnel’s lining to withstand the seismic and geotechnical loads. Each section of the tunnels are designed according to the maximum stress witch created due to the earthquake. this stress’s created in tunnels can be devided in to 3 category : the axial force,the Shear force and... 

With population growth, increased energy demand, and industrial activity, the amount of environmental pollutant emissions, including carbon dioxide, has risen, leading to climate change. This has resulted in the adoption of policies and decisions aimed at reducing emissions and combating climate change. Currently, the primary source of energy for societies is fossil fuels, and according to forecasts, the complete substitution of these resources in the near future is not feasible. Therefore, appropriate solutions must be considered for this transitional period to manage fossil fuel consumption while mitigating emissions and climate change. Carbon Capture and Utilization is recognized as one... 

Train-induced vibrations may become a source of annoyance to the residential environments and disturb the vibration-sensitive instruments. This paper aims to numerically study train-induced vibrations and affecting parameters such as foundation of the building adjacent to the railway, soil stiffness value and its variation pattern in depth and the train speed. To this end, a plane strain model was developed using finite difference program, FLAC2D. In order to simulate possible material damping of soil subjected to dynamic loading, hysteretic damping is incorporated into the model. The results of analyses performed in this study showed that increasing the train speed may not lead to an... 

In this study, an adaptive controller design for nonlinear fractional order systems in the strict-feedback form has been investigated. The system is subject to unknown dynamics, unmeasured state variables, quantized input and output, and input nonlinearity. A linear observer is used to solve the problem of unmeasured state variables. The fuzzy logic system is used to estimate the unknown functions, and instead of updating all the regressor weights, only the upper bound of their norms is updated, which significantly reduces the computational load. In the controller design, limitations due to the bandwidth of data transmission have been considered by applying quantizers in the input and output... 

Due to the importance of recognizing the underwater and the existence of danger to human life in this environment, the use of AUVs has greatly expanded. To build and use these vehicles, we need to model dynamic behavior, and control these systems. The nonlinear dynamics of the AUV makes it difficult to use common linear controllers. On the other hand, the coefficients used in dynamic equations have uncertainty and changes, and as a result, dynamic analysis may be probably un-accurate. If the controller is designed, the controller must be self-tuning and robust to be able to withstand changes and uncertainty. Adaptive control is an approach for controlling such systems. The main idea in... 

This study investigates the dynamics of a two-mass oscillator travelling on a viscoelastic rectangular plate under both accelerating/decelerating and uniform motions, while accounting for surface roughness and various reattachment scenarios. Despite its practical significance, this topic has received limited attention in scholarly literature. The Current article studies how key parameters—including the oscillator’s initial velocity, acceleration, foundation/oscillator damping and stiffness, as well as impact type (elastic, plastic, and elastoplastic)—affect the system’s dynamic response. It also examines, via illustrative examples, the oscillator’s motion along paths parallel and diagonal to... 

The abstract is the most important section of the thesis because many readers limit most of their reading to abstracts, saving in-depth reading for specific theses. It should give the reader a "preview" of what's to come. The abstract should emphasize new and important aspects of the study or observations. The purpose of the abstract is to allow researchers to decide whether or not to read the whole thesis. The abstract is what researchers read first to decide if the thesis is important, interesting, and it allows them to assess the relevance of a thesis to their own research, without having to read the entire thesis. Thus, it is crucial that the abstract both summarize succinctly the key... 

The low female labor force participation rate in the Iranian labor market relative to the global average and even to countries that do not differ significantly from the socio-economic characteristics of our country is one of the important questions of the Iranian labor market. In this study, we seek to answer the question of whether the economic participation rate of married women will increase if the gender gaps in wages, job findings and job losses among women and men are eliminated in the Iranian labor market. To answer this question using household expenditure and income data and labor force data, we show that between the two categories of occupations, in terms of the share of women's... 

Transition Metal Dichalcogenids (TMD) are types of 2D materials that exibit wide range of electronic, optical, mechanical, chemical, and thermal properties. These materials with MX2 general formula, have atract attentions with respect to their unusual properties because of their very limited dimensions. Their tunable properties and materials availibility make them attractive for wide range of applications. In recent years, chemical vapor deposition (CVD) methods are promising in preparing high quality TMD with scalable size, controllable thickness, and very excellent electronic properties. Also, chalenges are remaining in synthesis and transfering of TMD are difficulty for most of... 

Fatigue crack growth can have harmful effects on the reliability rotary machine. While an early warning to crack, can be used to extend the life of these expensive machines and increase reliability.Structural Vibration Condition Monitoring as a primary fault detection method, achieved to a lot amazing result and for this reason studies vibration behavior of cracked rotational shaft is a big issue for engineers of dynamic machine.In this research, first check the fault detection methods based on structural vibration condition monitoring, mode shape methods were extracted. Then by modeling rotational shaft in computer and creation of crack on it, fault detection quality of these methods have... 

It is important to provide an appropriate and economically method with technical and engineering considerations to stabilize excavated underground spaces. The necessity of this, especially for the construction of underground metro stations located in the cities which faces many problems, is more evident. In this research, it has been tried to introduce an optimal method according to the type of area for the construction of the underground station. In order to obtain stress and strain condition in structural elements and surface deformations due to different stages of excavating, numerical modeling in FLAC3D has been used. By examining the parameters that affect the sustainability of this...