Sharif Digital Repository

Briefly, the accomplishment of movies is based on their sales at the box office or gaining an achievement at the film festivals. Utilizing AI calculations and machine learning algorithms, various models have been proposed for the prediction of these achievements in the literature such as predicting the success of movies using regression models or the success of movies using discrete decision models is anticipated, and in another study the effect of social media data on sales investigated. The methods which are used to tackle these problems can be referred to as machine learning algorithms including neural networks, regression models, discrete decision-making models, public and experts... 

Control of complex networks is the main topic in this study. In this thesis, we consider the methods to steer the dynamics of a network from an initial state to the desired final state. To achieve this goal, one needs to inject appropriate control signals from some of the network nodes, known as driver nodes. We consider the quadratic sum of control signals as a cost function, to control the dynamics of the network. By minimising the cost function, we obtain the control signals as well as driver nodes for a linear time-invariant system. As an example, we provide the results of an energy minimization strategy to control the second order Kuramoto and Rössler dynamics in Erdos-Renyi and... 

Chlorophyll-a, as an important component in evaluating water resources, has a significant impact on the status of water resources. This component is dependent on various quality parameters, such as phosphorus concentration, nitrogen concentration, turbidity, suspended solid concentration, temperature, pH, and dissolved oxygen concentration in water. To evaluate the quality status of surface water, it is necessary to estimate the exact concentration of chlorophyll-a in different temporal and spatial ranges. The objective of this study is to simulate and predict the concentration of chlorophyll-a in different temporal and spatial ranges using a combined application of machine learning models,... 

Increasing in social communication via electronic ways has been made social network analysis of these communications more important each day. One of the most important aspects in social network analysis is community detection in such networks. There are many different ways to extract communities from social graph structure which in some of them the content of communication between actors has been noticed in community extraction algorithm. In this thesis after a short survey over advantages and disadvantages of existing methods for community detection, a new method for extracting communities from social networks has been suggested which in addition to streaming property of data it spot the... 

One of the most efficient techniques deployed for end-stage renal disease remedy is kidney transplantation, but in this case, we commonly encounter with the problem of gap between the demand of patients and supply of donors. In the majority of models has been proposed until now, either kidney exchange technique in a pool of incompatible pairs or kidney allocation system from deceased donors to waiting list is recommended. In this research, in order to enhance kidney transplantation plans, first, a hybrid conceptual model is proposed. Then, its mathematical model is discussed, in which some of the transplantations are selected from kidney allocation system before injecting to the pool of... 

Studying the performance of flow meters is of great importance in order to improve their quality. In this study, we are looking for an optimal design for a turbine flow meter in which the measurement accuracy, pressure drop and response speed indices are improved. For this purpose, a turbine flow meter with a diameter of 2 inches has been selected and its performance has been numerically modeled using computational fluid dynamics in a steady and transient state. By modeling the steady state, the measurement accuracy and pressure drop indices are obtained, and by modeling the transient state, the response time of the flow meter is obtained. In order to increase the accuracy of numerical... 

One way to increase the efficiency and improve the performance of a gas turbine is to increase the inlet gas temperature. On the other hand, the inlet temperature has an allowable operating range, and increasing it beyond the tolerance of the alloys used in turbine blades causes structural defects and significantly reduces the blade life. Therefore, to increase the blade life, various cooling methods such as internal and layer cooling are used. Considering the blade geometry and cooling paths, accuracy in the manufacturing process is doubly important in the production of these blades. The importance of this issue is that if the cooling channels produced are inconsistent with the design... 

The standard model of Cosmology (SM), based on Einstein’s theory of general relativity (GR), is the best model in describing the cosmic-scale observations. In galactic scales, however, galactic dynamics show a discrepancy between the observed luminous mass and the predicted value from the theory. Two approaches are suggested to eliminate this inconsistency: assuming the existence of dark matter within the context of GR, or modifying the theory of gravity in galactic scales, like MOND or MOG. In this thesis, we study the spherical collapse and the formation of shell galaxies in MOG, in comparison with SM. We introduce the action and the field equations of MOG and the equation of motion of a... 

Strongly Rayleigh measures are an important class of negatively dependent (repulsive) probability measures. These measures are defined via a geometric condition, called “real stability”, on their generating polynomials, and have interesting probabilistic properties. On one important property of negatively dependent measures is their rigid dependence structure. In other words, the it is impossible for these measures to have strong overall dependencies. In this thesis, we study two manifestations if this phenomenon: (1) paving property and (2) tail triviality. Informally, the paving property states that it is possible to partition the set of the components of every strongly Rayleigh random... 

Predicting groundwater level fluctuations is essential for effective water resource management and environmental preservation. This study examines and compares two modeling techniques, namely Wavelet Neural Networks (WNN) and Artificial Neural Networks (ANN), for predicting fluctuations in the aquifer levels in the Varamin plain. Traditional hydrological models often struggle to detect nonlinear relationships present in hydrological data, which may lead to inconsistencies in predictions. The research focuses on groundwater level fluctuations in the Varamin plain over a 30-year period, from October 1989 to September 2018. Statistical methods such as mean, median, and variance calculations are... 

This study evaluated the feasibility of upgrading the treated effluent from the Tehran Oil Refinery wastewater treatment plant for reuse as cooling tower makeup water. Due to the high concentrations of dissolved solids, phosphate, silica, and COD, the direct use of this effluent causes scaling, corrosion, and biofouling in cooling systems. To address these issues, a hybrid advanced treatment train comprising pre-oxidation and coagulation using ferrate (Fe(VI)), followed by mixed-bed ion exchange (MB400) and a final remineralization stage, was employed. The goal was to simultaneously reduce organic, colloidal, and ionic loads with minimal energy and chemical consumption and to produce a... 

In this thesis, consider three important questions in the Iranian Wholesale Electricity Market (IWEM) and answer its. The first one is whether the bidding behavior of the firms in the IWEM has been ex-post optimal? The results of the research show that, on average, the firm’s bidding behavior didn’t optimal in the IWEM, and therefore the bidding strategy of them could be improved. This issue is importance from the regulatory viewpoint in terms of assessing market efficiency and market power of firms, as well as from the firm’s point of view to improve the bidding strategy and increase its profits. The second issue is the assessment of the firm’s ability to exercise unilateral market power by... 

Office buildings, as one of the largest energy consumers in the building sector, play a significant role in national energy consumption. Given the importance of energy optimization in achieving sustainable development, reducing energy consumption in these buildings not only lowers costs but also helps preserve natural resources and mitigate environmental impacts. In this regard, providing energy optimization solutions, improving efficiency, and revising operational patterns play a key role in reducing energy consumption and ensuring user comfort. On the other hand, attention to indoor air quality is equally critical, as polluted indoor air can negatively affect the health and productivity of... 

This study develops an innovative modeling framework for the integrated assessment of energy systems, environmental impacts of greenhouse gas (GHG) emissions, and human health effects of air pollution. The primary objective is to analyze the co-benefits between GHG emission mitigation and the health benefits resulting from improved air quality for metropolises, moving beyond the conventional economic costs typically evaluated by energy models. For this purpose, a structured linkage is established between downscaling models for temperature, energy demand, energy supply, emissions, air quality, and human health impact assessment. An innovative recurrent ensemble model is designed for... 

Multi-part rotating parts are used in various industries with very high revolutions. Therefore, the method of assembling each part and keeping the axis of rotation of each part close to the axis passing through two supports (bearings) is important. In this research, three main steps are followed, the development of the differential equations governing the multi-part rotating system and the calculation of the range of oscillations created at the critical points, and then the calculation of the optimal assembly angles with the aim of reducing the introduced oscillations, and finally the discussion of crossing the speeds A crisis is being investigated. The method of obtaining the system of... 

MQTT (Message Queuing Telemetry Transport) is one of the essential and widely used protocols in the Internet of Things (IoT) networks. It operates at the application layer (Layer 7) for data transmission. As IoT applications using this protocol for communication have grown, securing such systems against security attacks has become a significant challenge. One of the important attacks implementable by IoT networks is Distributed Denial of Service (DDoS) attacks. In this thesis, we initially provide a general overview of IoT security and demonstrate how DDoS attacks disrupt the availability feature in these networks. We then examine known types of DDoS attacks to gain a better understanding of... 

There are several methods for measuring thin film thickness, however, for the analysis of liquid film motors [1] we need a method which is capable of measuring the thickness using a single image of the film. In this work, we use the colors that appear on thin films, such as soup bubbles, which is a result of light interference to calculate the thickness of the layer  

One of the most elusive problems in quantum mechanics is the transition between classical and quantum physics. This problem can be traced back to the Schrodinger's cat. A key element that lies at the center of this problem is the lack of a clear understanding and characterization of macroscopic quantum states. Our understanding of Macroscopic Quantumness relies on states such as the Greenberger-Horne-Zeilinger(GHZ) or the NOON state. Here we take a first principle approach to this problem. We start from coherence as the key quantity that captures the notion of quantumness and demand the quantumness to be collective and macroscopic. To this end, we introduce macroscopic coherence which is the...