Sharif Digital Repository

In this thesis, various fractional order controllers (FOCs), e.g., FO-PID, FO-TID, CRONE and FO-Lead/Lag, are implemented using PLC. For this purpose first, several methods are used to approximate the differentiator and integral operators. Based on these methods, the equivalent rational transfer functions of the fractional order controllers are obtained. Then, using STEP7 software, the FOCs are implemented in Siemens PLC. Moreover, to facilitate the use of the implemented FOCs in the industry and to take full advantage of the controllers, WinCC software as an interface between human and machine (HMI) is used. The WinCC software enables the operator to access the PLC through a computer (PC)... 

The phenomenon of vortex flow, is one of the most predominant streams in the nature. This phenomenon yielded by the motion of vortices, produces up to 1000 times acceleration of the Earth’s gravity. The issues of uncontrolled harvesting of oil wells and increase the life of the wells, which cause to increase in the extracted crude salt, reveal the importance of waste management and both handling and refining petroleum. According to global statistics, for every extracted barrel of oil, three barrels of water are yielded. Therefore, 250 million produced water barrels per day is produced.The separator technology with vortex core (brand Voraxial) is one of the latest technologies in waste-water... 

The structure and energy of vitamin B1 (Thiamine), vitamin B2 (Riboflavin) and vitamin B6 (Pyridoxine) have been studied employing quantum mechanical calculation, DFT methods at B3LYP level using 6-311+G* basis set. Values of the coupling constants involving carbon-hydrogen and hydrogen-hydrogen on the torsion angle α and β were theoretically calculated. All Karplus equations which represent the correlation between coupling constants 1JCH, 2JHH, 2JCH, 3JHH, 3JCH and proper dihedral angle have been yielded. The effect of three solvents, water, ethanol and carbon¬ tetrachloride with different polarity on coupling constants, energy and structural parameters were calculated employing PCM model.... 

In recent decades, the idea of multiverse has been raised in several areas of physics for different reasons. One of the interpretations of quantum mechanics, the inflation theory in cosmology and string theory in fundamental physics have led to the multiverse idea. On the other hand, after the problem of fine-tuning of the constants of nature became a hot topic in recent decades, physicists have tried to find a way to explain this puzzle. One of the most important approaches that have been suggested by some physicists, as a scientific explanation for this problem, is the idea of multiverse and they are even willing to set aside the principle of observability to confirm physical... 

Radio frequency identification systems (RFID) were used in the past to identify physical objects. Along with the development of RFID systems and its wide range of applications in our daily life, the need for privacy in such systems is becoming more and more significant. Authentication protocols are used as the care of secure communication to preserve the privacy and security in RFID systems. In this thesis the security of authentication protocols against general attacks are investigated, using two typical authentication protocols. As an alternative, we use a privacy model as another tool to analyze two other types of authentication protocols. The results reveal the weakness in the design of... 

The process of portfolio construction and optimization can be broken down into three main steps: selecting appropriate assets, allocating capital, and monitoring and adjusting the portfolio. This study focuses on evaluating the performance of the Hierarchical Risk Parity (HRP) method for capital allocation in investment portfolios, specifically in Iran’s capital market. The aim is to enhance the method's effectiveness by implementing alternative correlation calculation approaches, such as Wavelet and Chatterjee correlations. The study utilizes three different portfolios containing assets from the Tehran Stock Exchange, the US stock market, and the cryptocurrency market. The primary objective... 

Artificial neural networks are mathematical models inspired by the nervous system and brain. The types and applications of these networks are very widespread nowadays, and it seems that they can be used to track the signals well and estimate the data of the next. In this research, we try to present a model that can predict the future of the trend of noisy signals that have unpredictable behavior, or in other words, chaotic signals. Such research is also widely used in the medical sciences, including the diagnosis of epileptic seizures or heart attacks. In this research, a study with high volatility financial data has been done as an example on this issue and the proposed model tries to be... 

The aim of this thesis is the concept extraction of sequential patterns for imitative learning for humanoid robots. In such a way that an existent that has the physical and cognitive similarities, begins to extract concepts and learns by observing the behavior of the other existent. In this project, it is assumed a humanoid robot that can understand the concepts such as hello, goodbye and different concepts and does the corresponding actions from the visual and auditory information. In this thesis, a new model has been presented to eliminate the improper and meaningless elasticity in patterns sequence, such as changes in accent or elasticity in movements. This model is called the fuzzy... 

In this project, modeling, simulation, and control of the Saccharomyces Cerevisiae were studied. In the first section, simulation and control of a structural model of saccharomyces Cerevisiae were performed. Fuzzy Logic Controller (FLC) as a model-independent controller and Global Linearization Controller (GLC) as a model-based controller were designed. Additionally, two types of Kalman filters were designed to predict all states of the structural model: 1-Extended Kalman Filter (EKF), 2- Unscented Kalman Filter (UKF). As a concise explanation, the control action of the GLC is a function of all states of the model, and since that measuring all metabolites is not practical, the EKF and UKF... 

The primary purpose of acidizing operations in the oil and gas industry is to enhance hydrocarbon production. Acidizing has been a common and conventional method for years, especially when production engineers face issues like declining reservoir pressure leading to reduced production rates. Initially, the treatment solution is referred to as matrix acidizing. In acidizing operations, different additives are combined with the acid to control its behavior in the reservoir. These additives may include iron control agents, corrosion inhibitors, friction reducers, and more. Incompatibility among these additives, the acid, and reservoir fluids can lead to severe damage to the reservoir.... 

The goal of this research is the simulation of the annular combustion chamber of the turbine engine utilized by liquid fuel. The achievement to this goal will lead to create numerical tools for parametric study, analysis and combustion chamber designing.For this reason simple geometry has been considered. This simplicity of geometry causes to facilitate in parametric study and decrease in saving time for modeling and meshing. This combustion chamber is a simplified model of engine CF6. In recent study, the k – ε realizable model has been used for turbulence modeling. For non-adiabatic condition, chemical reaction is dissolved by utilizing probability density function along with laminar... 

During the last few years, the study of urban environment structures is considered as a research field of interest in remote sensing. In satellite observations of the earth's surface, continuous imaging in terms of time and space has caused the remote sensing technique to be proposed as a useful and efficient tool for the analysis of urban areas. Obtaining quantitative spatial information from the urban environment in fields such as determining the height of buildings plays an essential role in urban planning, monitoring damage to buildings, establishing communication bases and digital cities. During the last two decades, the use of Tomosar approach in order to reconstruct the structures of... 

In this work, the dynamic competition between firms providing internet services is studied. The framework is Markov equilibrium whereby structural parameters are obtained using two-step estimations, allowing for analyzing the situation in case of subsidies for service upgrade. The results show that such subsidy has little effect on the number of firms while increasing the number of fast firms  

Estimating the price elasticity of gas demand involves complexities depending on the gas market structure and pricing mechanisms in different countries. Distinguishing between supply and demand shocks and block pricing are among the main challenges that can cause endogeneity in elasticity estimates. Iran's domestic gas network, one of the largest and most extensive household gas markets, is divided into five climatic zones based on weather conditions. The pricing steps for these five climates during the five cold months are such that a customer in a warmer climate pays higher prices. Conversely, the pricing steps for the seven warm months are the same for all climates. This policy creates a... 

The correlation between religious adherence and voter turnout is widely studied. However, whether the relation is causal is an open question. We use Household Expenditures and Income Survey (HEIS) data in Iran, which encompasses nine distinct religious expenditures. These expenditures have low correlation with each other and represent different aspects of religious adherence. We use Imamzadeh (some historical holy shrines) as Instruments to estimate the causal effect of religious expenditures on voter turnout. The results reveal that religious expenditures influence both presidential and parliamentary voter turnout, with a notably stronger impact on presidential elections  

Mobile edge computing (MEC) is a promising technology that aims to resolve cloud computing’s issues by deploying computation resources at the edge of mobile network and in the proximity of users. The advantages of MEC include reduced latency, energy consumption, and load on access and mobile core networks, to name but a few. Despite all the aforementioned advantages, the mobility of mobile network users causes the traditional MEC architecture to suffer from several issues, such as decreased efficiency and frequent service interruption. One of the methods to manage users’ mobility is virtual machine (VM) migration, where the VM containing the user’s task is migrated to somewhere closer to...