Sharif Digital Repository

Nowadays millimeter wave imaging technology has found various applications in industry, medical and security systems. From one side the capability of penetration of this frequency spectrum into non-metal objects, and being harmless to humankind on the other side, has made this spectrum an appropriate alternative instead of dangerous spectrums such as X-ray. Recently, development of millimeter wave electronic circuits and antenna arrays has made the optimal design and implementation of millimeter wave imaging systems feasible. Among actions which have been taken in industry, medical and security systems until now, we can refer to efforts for detection of defects in production line,... 

Nowadays binary sensors such as infrared sensors are vastly employed in industrial, commercial and general applications due to their simplicity and low price. Beam sensors are common type of these sensors which can detect objects when they cross its beam. Sequence of sensors which are crossed in a time order is called sensor word. Consider an object, produced sensor word shows the order which it has crossed the beams. If we have more than one object then sensor word is combination of all sensor words produced by all object. We need to separate each sensor word. In this research, sensor word is developed to Fixed-Charge Minimum Cost Maximum Flow Network type.In this case, the consequent... 

Cosmic Microwave Background (CMB) and large scale structure observations are in good agreement with standard model of cosmology know as Lambda CDM. Standard model is based on cold dark matter and Cosmological constant. It also assumes that the cosmic initial conditions are Gaussian, nearly scale invariant, adiabatic and isotropic. Although this model is in good agreement with observational data, there are some important unsolved problems such as dark energy, dark matter and Missing Baryon Problem (MBP). Also there are some observational anomalies such as dipole and quadrapole alignment and hemispherical asymmetry in CMB fluctuations. Distribution of baryons in the universe and particularly... 

Using a general relativistic model for structures in a cosmological background, we calculated the Geodesics within a structure such as a galaxy or a cluster of galaxies in order to obtain the velocity profile of stars or galaxies. The profile defines a Newtonian mass which is then compared to different local gravitational masses, such as Misner-Sharp, Liu-Ya and ... to see how different they are. In this project we used numerical methods for solving geodesics equations of LTB metric and Einstein’s field
equations.
 

Nowadays, stock index forecasting has become an important issue for decision makers as well as investors, and such a forcasting is increasingly difficult thanks to multifarious impact of factors. In this regard, machine learning approaches can be used to analyze and predict the stock index and its influencing factors. Such an approach not only provides decision makers to make more becoming decision associated with the monetary and financial sectors of the country, but also allows investors to chose more appropriate portfolio (lower risk) by forecast long-term stock.In this study, we intend to better predict the stock index based on the necessity by examining the economic factors affecting... 

The appearance of renewable sources has created a more diverse energy mix and has made it challenging for grid operators to maintain stability in energy systems. The concept of a virtual power plant is the integration of different energy sources into a single entity that is collected and controlled through a central energy management system. It enables these sources to participate in electricity markets. This research presents a framework for the participation of a virtual power plant (VPP) in day-ahead (DA), reserve, and real-time (RT) energy markets. VPPs face several uncertainties, such as wind turbine (WT) production, demand, the status of calling the reserve, and energy market prices.... 

Tin sulfide with an energy gap of about 1.1 ev is a semiconductor suitable for applications such as solar cells, lithium-ion batteries, photocatalysts and other semiconductor-based devices. There are several methods for synthesizing this semiconductor at the nanometer scale, among which the solvothermal method is an efficient, controllable and inexpensive method. By precisely controlling the parameters of this process, two-dimensional tin sulfide nanosheets with high purity and desirable morphology can be produced. In this research, tin sulfide has been synthesized by solvothermal / hydrothermal chemical method and its metallurgical properties have been studied. Effect of solvothermal... 

The analysis of electrical energy consumption parameters such as rate and amount of consumption, plays an important role in the planning of power systems. Because the dynamic analysis and evaluation of these parameters provides a detailed forecast of consumption and power system load. these forecasts is given to planners and engineers as the input of power system planning .Given that the electrical energy consumption system can be thought as a dynamic system, System Dynamics (SD) method would be very appropriate for modeling and analyzing its behavior. In this thesis, based on the SD and by means of dynamic loops, a comprehensive dynamic system for electrical energy is introduced. So the... 

In order to reduce damage caused by power outages on rare events that lead to long-term disconnection of microgrid from utility grid, isolated mode performance of microgrids including wind and hudro turbines with energy storage systems is considered in this study. Using wind energy as a renewable resource is considered as an appropriate choice for power production in microgrids. However, the uncertainty in wind turbines power generation is something challenging. The existence of water resources near the wind farms causes a special opportunity for operation of these resources along with wind turbines. This thesis aimed at balancing energy supply and demand in island mode of microgrid,... 

The inevitable emergence of electric vehicles into the transportation industry in the near future can be a potential challenge or an opportunity for the power system. Vehicle-to-Grid can provide services for microgrids and the electricity market. The players of the game for participation of electric vehicles in microgrid or electricity market are vehicle owners, microgrid operators, and the aggregators. The formation and continuation of this interaction requires the interests of all institutions involved in the subject to be considered. Since there has not yet been an established conceptual or executive framework for the utilization of these vehicles in Vehicle-to-Grid idea considering... 

The market demand of super heavy crude oil is very low due to its determinative both physical and chemical properties. Unfortunately existing refineries in Iran are not capable to refine this kind of crude oil. Marketing issues besides great price difference with other crude oil types leads us to find economical solution for optimal use of this national possession. About 70 percent of super heavy crude oil produced from Soroush and Norouz oil fields is un-refineable materials and to refine this heavy crude oil to refinery products like gasoline or gas oil a refinery with RFCC ( Residual Fluid Catalitic Cracking) technology must be made. Super high Technology and very heavy capital cost... 

The use of wind energy due to the clean and unlimited nature of this energy has received more attention and for this purpose, the types of wind turbines that mainly include; monopile turbines and jacket-based turbines; is used In this research project, it has been tried using criteria such as equal weight of structures with different bracing shapes and taking into account the normalized energy and redundancy factors of the platforms; An optimal structure that can achieve a better capacity curve with the same material cost, which includes ultimate stress and greater ductility, and along with all the above factors; The redundancy of the structure has also been considered to minimize the risk... 

Anaerobic digestion of waste and wastewater has attracted researchers’ attention due to its important effect on reducing greenhouse gas emissions and reducing the level of environmental pollution and production of methane as a renewable energy source. This process is highly sensitive and can become unstable due to the presence of complex biochemical reactions and containing various types of chemical in it. In order to understand and improve the performance of this process, modeling and design of an appropriate control strategy is needed. ADM1 is the most accurate model for this process which is used in this study to describe and simulate the anaerobic reactor. Constrained and unconstrained... 

Anaerobic digestion of waste and wastewater has attracted researchers’ attention due to its important effect on reducing greenhouse gas emissions and reducing the level of environmental pollution and production of methane as a renewable energy source. This process is highly sensitive and can become unstable due to the presence of complex biochemical reactions and containing various types of chemical in it. In order to understand and improve the performance of this process, modeling and design of an appropriate control strategy is needed. ADM1 is the most accurate model for this process which is used in this study to describe and simulate the anaerobic reactor. Constrained and unconstrained... 

Final control elements usually have nonlinear dynamics which affect the stability of the closed- loop system. Four most common types of these nonlinearities are dead-zone, backlash, hysteresis and saturation. Because most of final control elements especially in chemical processes are subjected to saturation constraint and also due to lack of generaland practical control scheme to handle this limitation, our concentration will be focused on saturation nonlinearity. In this work, based on sliding mode control strategy, a control scheme for multi-input multi-state systems in the presence of input saturation is presented. Some numerical simulations are carried out to show the effectiveness of... 

In restructured power system, the Independent System Operator (ISO) implements Security Constraint Unit Commitment (SCUC) for clearing of day-ahead market. In this project, SCUC is also uses for simultaneous clearing of energy and reserve market. Spinning reserve and of generating units and Interruptible Loads (IL) are considered as system operating reserves in the proposed model. Some of IL usage restrictions such as maximum load curtailed, maximum curtailment hour in a day, maximum length of each curtailment and etc is also considered. One of these constraints is interruption time (the time between ISO’s request and IL’s Answer) which is very difficult to formulate. Expected Energy Not... 

The micro-scale channel creation in Osteochondral scaffolds is a prominent issue in tissue engineering. In this project we tried to identify the relevant parameters to obtain the method for injecting a biodegradable photo polymer to achieve a micro channel by predictable size.Due to inadequate accuracy in measuring the properties of the non –Newtonian working fluid, it was decided to use the Newtonian fluid equations in this study. The relevant equations for injecting the liquid under constant pressure were extracted. The modeling and design of micro syringe system was then completed. Using the made set up experiment to measure the fluid viscosity were performed.The next step was the... 

In order to reduce investment and operation costs of the power systems, transmission expansion planning is inevitable. In fact, transmission expansion planning is to determine when, where and how many lines need to be added to power system with a minimum of investment and operating costs. In this thesis, transmission expansion planning has been performed at uncertainty in generation and N-1 criterion condition where uncertainty in generation means uncertainty in the moment of adding power plant to power system. In previous studies, transmission expansion planning was performed with DC-load flow in which, the power loss and voltage profiles were ignored due to the approximation in the... 

The electric power industry is experiencing important changes brought about by the deregulation. Electric power generators and users engage in power transactions which take place over the transmission system and create losses. Transmission losses represent up to 1⎯5% of the total generation, and cost millions of dollars per year. Consequently, the problem of “who should pay for losses” arises and the satisfactory sharing of the transmission system utilization costs among all market participants has become a key issue. Unfortunately, losses are expressed as a nonlinear function of line flows, and it becomes almost impossible to calculate exactly the losses that are incurred by each generator,...