Sharif Digital Repository

Although technological specialization has been recognized as a stimulating factor of international trade (Ricardian theory), new approaches emphasize the endogeneity of technological heterogeneity across countries. Following them, we proceed to examine the effect of free trade on technological differences among 20 OECD members during 1996-2008. We first use the model of Eaton and Kortum (2002) to obtain an annual estimate of technological heterogeneity within the OECD group. We then analyze the behavior of this index facing international trade statistics in the same period. The results show that the OECD countries have been experienced a technological convergence, thanks to a boost in the... 

International trade arrangements have been considerably developed in recent decadees. Especially, one can note the role of these factors in economic development and improvement of life standards in member countries. In the meantime, Economic Cooperation Organization (ECO) was established in 1985, by Iran, Pakistan and Turkey and then extended by seven other countries: Afghanistan, Azerbaijan, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan. Improving economic development and intra-group trade of member countries is one of the main objectives for the group. The purpose of this research is to estimate the ex-post effects of ECO on the intra-group trade of member countries.... 

In this article we investigate the impact of trade openness on labor force participation rate. We use tariff rate as the main indicator of trade openness and we employ the number of regional trade agreements of neighbouring countries to diminish the endogeneity of the tariff rate variable. The results of the article show that the correlation of tariff rate and participation rate is negative and significant. Moreover, this correlation is robust controling for different variables and using various regression specifications. 1 percentage point decrease in tariff rate is correlated with 2-3 percentage point increase in participation rate and this relationship attenuates in the medium-run  

Decomposition of a graph into it’s subgraphs is an important problem in Graph Theory and Combinatorics. In this thesis we investigate some papers and their results about the problem of the decomposition of a complete graph into 4−cycles. In chapter 1 we express some parts of a paper written by Bryant, Darryn, Horsley, Daniel, and Pettersson. After giving some definitions and notations about cycle systems and their spectrums, we use methods of the paper to give a proof for a theorem on the existence of a decomposition of complete graphs into 4−cycles. In the next three chapters we explain results of a paper written by Bryant, Darryn, Grannell, Mike, Griggs, Terry, and Mačaj, Martin. chapter 2... 

Sudoku is an intellectual game based on mathematics. Sudoku achieved global fame in a short time because this game doesn’t need any mathematical operation like addition and multiplication and in theory, instead of numbers, lechers, shapes,colors, etc. could be placed.Sudoku which is a single-player game in generally the player should complete a partial n2 × n2 matrix M all of whose enteries are drawn from {1; 2,..., n2} by applying the rules: no number may appear more than once in any row, any column,or any of the nine ‘‘blocks’’. Actually blocks are n × n submatrixs with indices {na + 1, na + 2,…, na + n} × {nb + 1, nb + 2,….., nb + n} Actually, A Sudoku is A Latin square with one... 

a graph into specific subgraphs. Specially, decomposing the edges of a complete graph into cycles with determined length draws the main attention. Most of the former works in this area were studied the Alspach conjecture. In another words, Alspach conjecture states that ” Is the obvious necessary conditions for decomposing a graph into cycles (equality of the edges count with sum of cycle lengths) with specified length but not necessarily identical are also sufficient.” Different cases of Alspach conjecture have been studied and proved completely.The decomposition of a complete graph into cycles with the same length k is called k-cycle system. Steiner triple system is a 3-cycle system.... 

In mutual funds, due to the liquidity advantage, investors can trade their assets without paying cost. Flows dilute the effect of returns because funds cannot be invested immediately in high-risk assets or the fund manager cannot implement the optimal strategy. The effect of diluting cash flows can affect the fund's future performance and reduce shareholder returns. The effect of diluting the fund of flows in Iran is a very small amount of 0.08% per year, which is different from zero at a significant level of 5%, but economically this number is small and insignificant. Of course, the policies of investment funds and the pricing model of the value of the fund's assets can affect it and affect...