Sharif Digital Repository

Increasing advances in millimeter-wave imaging have given the new technology a special place in military and civilian activities. A very important advantage of this imaging system, which has led to its rapid development and growth, is that unlike methods such as X-ray imaging, the millimeter-wave signal is completely harmless to the human body. Because millimeter-wave imaging is non-ionizing, allowing for non- invasive imaging. Also, the millimeter-wave easily passes through human clothing and is reflected when it hits the human body, metal and ceramic objects, and some other objects. As a result, it can be used to photograph underwear, insensitive and safe places such as airports. In this... 

Statistics show that plastic production in the world is increasing, with 335 million tonnes in 2016 reaching 367 million tonnes in 2020. Since the presence of plastics in the dimensions of micro and nano, especially in aquatic environments can have adverse effects on human health and other living organisms, it has raised major environmental concerns. Therefore, it is necessary to think of measures to remove them and develop efficient methods for eliminating and decomposing microplastics. Recently, the advanced oxidation processes have attracted much attention because of the ability to eliminate recalcitrant compounds. In this study, electrochemical techniques and Fenton-based techniques for... 

The goal of this project is finding an appropriate method for controlling four different bioreactors with unknown dynamics. At first, an introduction to bioreactor dynamic hase been presented, then their nonlinear behavior has been discussed. In the following, four output control systems using adaptive neural network have been designed separately for four different dynamics. The applied control method has been adapted from a method of references with some changes. Performances of designed controllers in set point tracking, load rejection and model mismatch have been evaluated using simulation. In these studies, input saturation has been considered in simulations but it is not existed in... 

The importance of vocabulary, the building blocks of every language, in having a good command of a second language is evident. However, the best way to improve the lexical knowledge of the students is an issue that is open to discussions. This study aimed at investigating three different methods for teaching new vocabularies to Iranian students who were striving to take command of English as a second language in order to determine the advantages of one method over the other in terms of immediate and delayed retention. In this endeavor, we set 105 intermediate adult learners of English into three groups and instructed each group with a specific method, teaching them a number of new words... 

In this correspondence, a non-linear method of convergence accelerating and improving for iteration based algorithms is introduced. After convergence analysis, some enough conditions are proposed to guarantee convergence of the algorithm.For the sake of low complexity implementation of the proposed algorithm, some simple stabilizing methods are suggested. Simulation results show desirable performance of the proposed method and its capability to stabilize the iteration based algorithms. In the literature of missing samples recovery, the proposed method is applied to an Iterative Method (IM) as a general signal reconstruction method,then it is extended to the image recovery problem where... 

The occurrence of natural disasters and damages caused by them has greatly impacted humans' lives, which reveals need for us to prepare for confrontation with various disasters. For this purpose, in this research, we are seeking to develop a programming model to reduce damages caused by various disasters. This thesis includes 3 main sections. In first section, some major impacts of disasters are reviewed and studied during the past 118 years and some major lessons are summarized based on statistical data analysis. In second section, a 3-demontional probability density function has been developed to categorize different types of disasters. Furthermore, a scaling system is presented to... 

Increasing dynamics of mobile users intensifies the Doppler effect and degrades the performance of the communication system. Considering Fourier kernel-based modulation, in this research, we focus on dealing with the Doppler effect and compensating non-ideal communication channel response suffered from the Doppler-delay spread. In the first step, we study Zak transform and present a new transform for 2-D representation of time signals. This mapping is a well-known transformation that can be considered as a generalized discrete-time Fourier transform in the field of signal processing and can be used to represent a signal in the delay-Doppler domain. After providing a new 2-D transform, we... 

Pyrotechnic devices are widely used by the aerospace and defense industries and consist of a broad family ofsophisticated devices using self-contained energy sourcessuch as explosives and/or pyrotechnic compositions.Pyrotechnic shock, or pyroshock, is the transient oscillatoryresponse of a structure to loading (high frequency, highmagnitude stress waves) induced by the detonation ofpyrotechnic devices incorporated into or attached to thestructure.Pyroshock Test is one of importantenvironmental tests in satellite design process. Pyroshock is one of loads that exerted on spacecraft and it's subsystems during launch process. Pyroshock can cause failure in some subsystems like sensitive... 

This thesis presents a new method for scheduling wind generation companies to participate in day-ahead market. The assumed market structure of this thesis, considers day-ahead energy market and balancing market, simultaneously. The stochastic model of this, implements a robust function to face the uncertainties of these markets. The risk of participation in these market are controlled with Information Gap Decision Theory (IGDT). Finally the allowable percent of each uncertain parameters are introduced to met an specific level of profit for the company  

One of the main components of any solar power plant is the heat storage. Implementing heat storage reduc-es the cost of power generation by increasing the capacity factor of the system. This Thesis aims to analyze the operation of heat storages by modeling latent heat
storage. In this regard, an efficient method named "Method of Characteristics" is utilized. Models developed based on this method are possible to be used for comparison, sensitivity analysis, and optimization due to their low computation time. Sensitivity analysis was carried out based on various parameters such as void fraction, fiUer material size. Results show that using latent heat storage, storage c-apacity is... 

Does the household attribute changes to its economic conditions during the term of the MPs, and chooses to vote with regard to these conditions, including income and employment status, or who decides, regardless of economic characteristics, in this regard Takes? In this study, using micro data of the household income and expenditure survey and building a sample household for each district, we compute economic characteristics for each election district including total income, total cost, employment rate, employment in the government sector, and unemployment rate. . Election data includes the name, vote and status of the candidates for the ninth and tenth Islamic Consultative Assembly... 

To understand the link between the capital misallocation and financial repression in less-developed economies, we put forward a dynamic theoretical macro-finance model with information asymmetry between firms and the bank. While there is no exogenous instrument for the bank to asses firms’ productivity, we let him update his belief about firms’ productivity, based on their records. We show in the presence of asymmetric information and weak formal contract enforcement systems, in the short-run, increasing the interest rate may increase capital misallocation since the moral hazard problem of strategically defaulting of firms can cancel out the screening mechanism of increasing the interest...