Sharif Digital Repository

Software modeling is one of the most important activities in the Software Engineering domain. Models provide an abstract view of the system, thereby facilitating their understandability and resolving the complexities and problems involved. Indeed, models can be considered as a roadmap for achieving the goal of producing software-intensive systems. The aim of real-world modeling is to identify real-world entities, their interactions, and the constituent activities. Real-World Models are tangible to all stakeholders and provide them with an overall view of the Problem Domain. Therefore, many software development methodologies are based on modeling the real world. In some of these... 

Social learning approach in economic policymaking is introduced against conflict-based approach in the similar context. Helco, 1973 first studied the effects of such a learning in economic policymaking and said ”men collectively wondering what to do… Governments not only ‘power’… they also puzzle.” The important point in studying policymaking through social learning approach is paradigm shifts in peoples’ mental models. In this approach, policies are not only the result of conflict between different interests but also are the output of a learning process. In this research we first assume that social learning has not occurred in policymaking community and that individual learning has... 

In two past decades, a revolution has occurred by emerging of substation automation system in field of substation control and protection system. The traditional control system has changed to the modern automation systems which are based on computer networks. The development of this project become possible by having experience in and being familiar with automation systems, studying equipment specifications, tasks, and criteria and analyzing operation of various systems. The main target of this thesis is evaluating the automation system precisely and exhaustively and developing a model based on mathematical relations. This model is founded based on the application and analysis of the networks.... 

The present research investigates the conjunction of two areas of pricing and negotiation techniques to find a relationship between price and other key factors such as quality, quantity, time, etc. and observe the overall effect of these factors on how to design and implement negotiations over price in B2B environment. The research presents a model to describe the process of negotiation and applies quantitative methods to rank negotiable scenarios. This set of scenarios, then is sorted in a triangular model of negotiation strategy and is used as a roadmap for negotiation. Furthermore, researcher evaluates effective tactics and their implementation to drive negotiation sessions based on... 

Thermodynamic modeling is a useful method for predicting of asphaltene precipitation due to various reasons, such as CO2 injection, mixing of different oils in oil storage and pressure changes. However, the application of solid model and thermodynamic micellization model, for prediction of asphaltene precipitation under gas injection condition, hasnot been improved. In this work, two computer codes which are based on two different asphaltene precipitation thermodynamic models, 1-Thermodynamic Micellization Model and 2- Solid Model, have been developed, and, used for predicting of asphaltene precipitation data reported in the literature as well as the experimental data obtained from high... 

Over employment is a common phenomenon in Iran. Over 61% of the labor force with more than 31 years of work experience have worked more than 42 hours a week in year 2000. This amount, increases for the years 2001, 2003 & 2004 as 65.9%, 68.5% & 72.1%. In this research, we examined the possibility of job opportunity reallocation by increasing the overtime premium between over employed and unemployed labor force in Iranian labor market. For this goal, we estimated the determinants of overtime incidence and hours according to single selection & double selection approach, Tunali (1986). Pooled data from urban Iranian labor force- year 2005- was collected and analyzed. Our results clearly show... 

One of the best methods of gait analysis is to use analytical models. In this project, first, the normal human gait was simulated using a two-dimensional biped model with 7 segments, i.e., a HAT segment representing head, arms and trunk, and 6 segments representing thighs, shanks and feet of the two legs. The foot-ground contact was simulated using a five-point penetration contact model. The elastic impact and friction effects are considered in the ground reaction force modeling. Optimization of the normal human walking model provided constant coefficients for simple PD controllers’ (driving torque) equations that could reasonably reproduce the normal kinematical pattern. Then, in the second... 

The role of government in economy has been a controversial subject in economics. Lately, there has been some fundamental change in evaluating this subject. One could mention two of these as 1) realizing the importance of micro-founded macro model for evaluating policy, and 2) taking into consideration the rent-seeking behavior of politicians. In this research, a general equilibrium in a micro-founded macro model will be discussed and then in political economics framework, the effect of government on this equilibrium will be investigated. Only the redistribution role of government has been considered. First, the model in which a benevolent government is seeking optimal policy is Discussed.... 

This thesis analyzes the behavior of inflation in the Iranian economy by introducing a micro-founded model of monetary policy. The model predicts a direct relationship between inflation and oil export revenues in the oil dependent economy of Iran. This theory driven claim is verified empirically, and test results tend to confirm a meaningful relationship between inflation and Oil export data in Iran. Based on results attained from the micro-founded model, an augmented SVAR model is proposed for estimating underlying inflation in the Iranian economy. The proposed model is found to render better results than the conventional models used for estimating underlying inflation. Moreover it is... 

The notable share of housing sector in GDP (approximately five percent) shows this sector’s relation with macroeconomic activities. On the other hand, House as an asset leads housing sector to be affected by monetary and fiscal variables. A dynamic panel data was used in this study to evaluate the relations between housing sector and some macroeconomic variables in metropolises of Iran. As results show, in long term growth of liquidity, GDP per capita and sharp ratio have positive effects, and land per capita has negative effect on housing price in metropolises of Iran. Price increases have not been equal in different cities. Inequality of land price between metropolises and between... 

In this research, an Index of Iran informal economy in response to the government interventions in credit, labor and product markets is stimated by EMIMIC model. To do this, first these interventions are measured using principal components analysis. In the model, the variables GDP and employment are used as indicators and taxation rates, government distortions in credit, labor and product markets, government expenditure, per capita income, unemployment and inflation as causes of the informal economy. We conclude these government interventions have affected Iran informal economy and their influence is more than indirect interventions influence such as taxation. The estimated index of Iran... 

Heartbeat is the result of contractions of over 10 billion cardiac cells. These cells’ cytoplasms are connected to each other by gap junctions which are arrays of intercellular protein channels. Thus action potential can propagate from one cell to another and cause its contraction. In core-conductor model, one-dimensional microscopic representation of cardiac tissue, cells are attached to each other to form a ladder network. The parallel elements are connected to each other by series resistors which represent gap junctions. These resistors are nearly always considered as static elements. In this thesis I have investigated the effects of incorporating the dynamicity of gap junction resistors... 

The heavy ion collision experiments are in progress in order to investigate how the Universe has evolved after the Big Bang. The recent observations show that a nearly perfect fluid is produced after heavy ion collisions. An appropriate incorporation of the relativistic hydrodynamics and the field theory would help us to describe the dynamics of QCD (Quantum Chromodynamics) matter under extreme conditions, and to survey the expected phase transitions. The majority of efforts to investigate the characteristics of the QCD plasma are devoted to an ideal, non-dissipative one. To get the results which are highly in accordance with the experiment, it is necessary to bring also in mind the role of... 

One of the most important problems in using wind energy is the estimation of wind energy potential of a region with acceptable accuracy. To use wind energy and convert it to electrical energy it is necessary to study the economical aspects of wind farm installation, and to choose an appropriate wind turbine to be installed in a region. To do such a study and to choose approperiate wind turbine, annual energy output of different wind turbines should be estimated in that region. The porpuse of this thesis is to develop new methods to estimate annual energy production of a wind turbine by using some of the parameters of wind speed pattern of a region such as wind speed average, wind speed... 

Using field assisted dissociation model and with a classic view the dissociation probability is calculated when it a molecule is exposed with a Ti:sapphire laser with wavenumber of 800nm and the energy of . using gradient optimization method we find a tailored two rectangular laser pulse for controlling the dissociation of C-H bond of . Using classical method reduced the complicacy of solving schrodinger equation. In our optimization method in contrast with the usual controlling method experimental data is not needed and this reduced the controlling costs.

 

In order to better understand the performance of the Iranian health insurance industry, household decisions to purchase private health insurance are analyzed using a two-stage (Heckman) model on Survey of Family Income and Expenditure data. Probit and OLS regressions are used to examine the factors influencing the probability and amount of private health insurance purchased. Generally, factors affecting the probability of having insurance also influence the amount of insurance coverage purchased. The results show the importance of some demographics on the insurance decision, particularly age, gender and marital status. Socio-economic factors such as education, income, employment sector,... 

Magnetic Shape Memory Alloys (MSMAs) are a category of active materials which can be excited by magnetic field. These alloys have been used in sensor and actuator applications recently. MSMAs posses special properties such as large magnetic field-induced strains (up to %10) and high actuation frequency (about 1kHz), while ordinary Shape Memory Alloys can’t act in frequencies above 5Hz due to the time involved with heat transformation. In this thesis, MSMAs are modeled by means of incremental modelling which is a useful method in analysis of nonlinear behaviour of materials. Furthermore, stress-strain curve of MSMA is approximated using an analytical expression whose parameters can simply be... 

In this paper, a one-dimensional and two-dimensional numerical approach is used to study the effect of various parameters such as micro combustor height, mass flow rate and external convection heat transfer coefficient on the temperature and species mass fraction profiles. A premixed mixture of H2-Air with a multi-step chemistry (9 species and 19 reactions) is used. The transient gas phase energy and species conservation equations result in an Advection-Diffusion-Reaction system (A-D-R) that leads to two stiff systems of PDEs, which can not be solved by conventional Computational Fluid Dynamics (CFD) methods. In the present work, Strang splitting method, which is suitable for nonlinear stiff... 

In industries there are many nonlinear processes which cannot be easily controlled with classical methods. Model predictive control is a useful method for nonlinear processes which not only has high efficiency, but also extension of this control to interferential multi variable case, with constraint on the controlled and manipulated variables and other problematic dynamic specifications such as slow dynamics and inverse response is very simple. Industrial polymerization processes are regarded as significant nonlinear processes. Optimization and control of polymerization reactors have considerable importance in process applicability and in economics. The molecular structure of polymer such as...