Sharif Digital Repository

Exporting firms face a range of challenges when entering international markets, among which financial constraints are particularly significant. Financial constraints can impair a firm’s cash flow, making it difficult to finance the fixed costs associated with export market entry. This study constructs a firm-level index to measure the degree of financial constraint and examines its impact first on the probability of export participation, and then on the volume of exports. The analysis is based on data from Iran’s industrial firms between 2008 and 2019 (1387–1398 in the Iranian calendar). The effect of financial constraints on the probability of exporting is estimated using logit and linear... 

The land market is one of the most important markets in the economy. Land is a factor of production, store of value, and a major part of household’s portfolio. Although price of land is an essential information for institutions like municipalities whom tax the landlords, or for financial intermediaries like banks whom use the land as collateral, studies about price of land and its spatial and time variations are scrace in Iran. Furthermore, most of studies in other countries are usually based on inflexible OLS estimators. Thus, this study has two main contributions. First, to analyze the usefulness of hedonic modeling in explaining the price of land, utilizing a unique dataset for Tehran... 

In this project we tried to examine the effective variables on rent to price ratio and how the variations in R/P influence households’ decisions. Using rent to price ratio, the efficiency of Housing market has been inspected. However, the results for Tehran are in contrast to efficiency assumptions. Moreover, having access to unique database which remarkably increase the accuracy of our estimation, the relation between rent risks and House price has been examined. The results show that rent fluctuations has positive impact on house price. Rent to Price ratio has different applications and we tried to determine the variables that can explain this ratio. Literature review demonstrate that... 

Forecasting has a crucial role for decision makers in economics and finance and is frequently used by firms, government institutions and professional economists. Academic studies in macroeconomics modeling and economic forecasting have been historically concentrated on models with few variables. But in practice, a decision maker has a large amount of information in the form of variables which has some predictive content for the target variable. One way to handle the large-scale information in forecasting is to use forecast combination methods. These methods generally combine the simple forecasts of some target variable while the forecasts are weighted according to their relative accuracy,... 

In this thesis we are going to forecast the hourly consumption of the electricity over the country with two models and then, combine them. The first model decomposes the consumption to a deterministic trend and a stochastic residual. The second one assumes that the trend part is also stochastic.Once the consumption is being predicted separately by the models, in the second part of the thesis, we will combine the results to get a final prediction. This prediction is going to be compared with the load forecast of the Dispatching Unit of the electricity network as a base model. We are going to answer two important questions: firstly, does combining the models give a better prediction or not,... 

Implying non-model based approach and using seasonal data, we determined cyclical component of housing market and discussed about its lagging or leading behavior to overall economic business cycles in Iran. To extract cyclical component we applied band pass filters, including Hodrick-Prescot, Baxter- King, Butterworth and Christiano-Fitzjerald, and Bry-Boschan’s algorithm on any time series which is able to explain housing market’s behavior in aggregate level. After examining many criteria we found that real residential investment in urban cycles depict cyclical behavior of housing investment. Real residential investment’ cycles in urban lag monetary base rate cycles and m1 rate cycles which... 

Housing policy formulation should be informed by a careful understanding of the behaviour of the housing market, as reflected by housing demand. Since Housing is a complex outcome of cultural, economic and regulatory environment, cross-city studies may be helpful. This thesis sheds light on housing demand in Tehran and Mashad, based on microeconometric data from 0319. In this study, we divided housing demand to three choices: tenure, location and size. The study finds that although price and education variables in Tehran is significantly effective, in Mashhad is not effective. But age variable is significantly effective in both cities  

Business cycles have been always one of the main issues discussed in macroeconomics. Nonlinear trend is one of the main characteristics of business cycles. Linear models are not able to explain this nonlinear nature. In order to capture nonlinear features of variables such as change rate of housing price or GDP which have severe ascending and descending and nonlinear behavior, regime switching models, specially Markov regime switching model, have been replaced existing linear models. Comprised to other models, regime switching model has a main advantage: this model is able to consider two important features of business cycles, i.e. asymmetry of different stages of business cycles and... 

We examine the economic implications of the SEC disclosure rules for companies doing business with Iran on their riskiness of debt. We exploit Section 219 of the Iran Threat Reduction and Syria Human Rights Act (ITRA), which requires companies listed on U.S exchanges to disclose their activities and transactions with Iranian institutions. We analyze the impact of the first ITRA disclosure on the cost of capital for both American and foreign companies listed on the US exchanges. Using a difference-in-difference approach, we document a negative impact of ITRA disclosures on loan spread and credit rating of foreign companies. Further, using textual analysis, we identify the elements in the... 

Jean-Pierre Serre in 1955, in his famous article “Faisceaux Algébriques Cohérents” asked if there is any finitely generated projective module on polynomial rings which is not free. Or equivalently: is there any non-trivial algebraic vector bundle over an affine space? The negative answer to this question is known as Serre’s conjecture and it was an open problem in algebra and affine algebraic geometry until 1976, when it was proved independently by Quillen and Suslin. The challenge of solving this question and its consequences led to a vast amount of research in commutative algebra, homological algebra and algebraic K-theory and inspired generalizations and similar questions. In this thesis... 

The alloy steel plant was exploited in1999; and the maintenance department starts its function and its activities according to the written PM software by Austria’s BOHLER Company. The PM program was written for the entire factory. Having worked with the PM for eight years, now it is possible to evaluate its performance. There are two main problems in the maintenance system; firstly, the existing PM System is incomplete, some important feature of the PM program is incomplete. Secondly there are lacks of a good auditing system to evaluate the PM orders. To evaluate the weakness of the current PM system and to study application of TPM, a section of the factory was... 

The purpose of this research is the aerodynamic design of a 100 kW transonic ducted fan. Today, the aviation industry is moving towards the design of electric driven aircraft propulsion. Transonic ducted fans are one of the viable options that have been used in medium and heavy aircrafts due to their high specific power. In this research, the meanline model has been used for the initial design. By applying the design constraints, design limitations, design and functional parameters, the initial design point is found and then a sensitivity analysis is performed with respect to the effective design parameters to obtain the optimal design point. For the initial design of the transonic ducted... 

The electrical conductivity of the solution has been one of the important physical quantities in many application. In this respect many probes and devices such as conductive sensors have been devised. In this study electrical properties of different water samples at frequency step range of 100-100000 Hz are measured by using the long cylindrical capacitive sensor and a measuring module (LCR-703). Operation of the capacitance measurement module for such probes is based on the auto balancing bridge method. Comparison of the measured capacitances and measured resistances for different water samples shows a decrease by increasing the measurement frequency. In another study the dielectric... 

Permeability is an essential parameter used for reservoir evaluation, simulation and management to optimize oil recovery. The conventional approach to estimate reservoir connectivity, conductivity, sweep efficiency and other critical information for decision-making is to build detailed geological models, which are then upscaled to a coarser grid where flow simulations are run. However, this takes many hours to be carried out even for a single realization practically. In practice, a very small number of realizations are considered and consequently the true uncertainty in the results is very poorly estimated. In this study, a statistical model of isotropic overlying sandbodies is used to...