In this research, in order to investigate the effect of the piezoelectric patch which is used as a sensor or actuator in rotating flexible structures such as a helicopter blade, the free vibrations of the rotating rectangular sheet with and without the piezoelectric patch have been presented. First-order shear deformation theory is considered for plate displacement and piezoelectric field. Considering the effect of Coriolis acceleration, centrifugal acceleration and centrifugal in-plane forces, the equations of motion are derived from Hamilton's principle and the electromechanical couple equation is obtained from Maxwell's equation. For piezoelectric, two electrical conditions, open circuit and closed circuit, which are used in sensors and actuators, respectively, have been considered. The equations are discretized with the help of the numerical method of generalized differential squares and the matrices of inertia mass, eccentricity, Coriolis and stiffness matrix are obtained. Natural frequency values for beam and rotating plate have been compared in Abaqus software. Also, the values obtained from the numerical solution in MATLAB have been verified with articles and ABAQUS, which have high accuracy. The effect of parameters such as hub radius, rotation speed, sheet thickness, aspect ratio, piezoelectric patch thickness and applied voltage on the natural frequency of the system has also been investigated.

Inflation constitutes a significant economic challenge for both citizens and policymakers. A crucial step towards mitigating inflationary pressures and enhancing purchasing power lies in identifying the underlying causes and mechanisms. This study investigates the impact of various factors on inflation dynamics in the Iranian economy, including adaptive and rational expectations, liquidity growth, demand shocks, exchange rate shocks, and government budget deficits. By examining these factors within the framework of established inflation theories, the study aims to inform more effective inflation control and management policies. Employing the generalized method of moments (GMM) and utilizing time series data spanning 1973-2022, the study finds that exchange rate shocks, liquidity growth, and government budget deficits exert the most significant influence on inflation rates in the Iranian economy. Based on these findings, policy recommendations include: reforming foreign exchange policies, adjusting the exchange rate system, controlling liquidity growth, restructuring government finances, and implementing appropriate contractionary monetary and fiscal policies.

Today, the economy and sports industry are concerned as one of the most important economic sectors in all countries, especially developing countries. Sporting goods exports has always been one of the topics discussed economic decision-makers in the context of sports economy. Considering the importance of this sector of the economy sports, this study aimed to investigate convergence of exported goods group during 1992-2012 sports industry in Iran. The research method for the price pair is econometric generalized method of moments by using the Beta and Sigma convergence method in order to investigate the convergence of the grouping. Grouping goods including clothing, shoes, balls and sports equipment. The results showed that there is beta convergence in the sport of exported goods, the rate of convergence in this factor 0. 674 is statistically significant and indicates that the speed of convergence. Also, Sigma convergence test results approved the existence of convergence and reducing the deviations groups are through time. This factor is also statistically significant. Considering the results of the beta and sigma convergence can confirm the existence of convergence in exporting sporting goods group acknowledged Iran during the period studied.

How should the government budget be allocated to public education, higher education, health, transportation, IT, energy, or indirect public services including expenses on laws and regulations, business governance, and tax reforms. We examine data between 1989 and 2019 of public spending and their outcomes for each affair and title. The results show that despite the fact that the number of students declined over time, the spending on public education has been raised. The structural model is estimated by generalized method of moments, and the estimates show that households put significant weights on education and health, as well as energy. However, even with considerable weights on these public goods, due to inefficient production of public services, the counterfactuals illustrate that more spending on tax reform, business environment, and governance relative to actual budget is optimal.

Management earnings forecast is one of the most important information resources in capital markets. The literature suggests managerial overconfidence is an effecting factors on the earnings forecasts’ accuracy. Because of users' relying to forecasted information, examination of the bias's effects on forecasts' accuracy is important. By using a new managerial overconfidence assessment model and generalized method of moments (GMM) regression analysis, the paper examines this managerial bias’ s effect on management earnings forecasts’ error in the firms that have listed at Tehran Securities Exchange (TSE) during the period from year 2007 to year 2016. The results show Chief Executive Officers’ overconfidence has a significant positive effect on earnings forecasts’ error, how overconfident Chief Executive Officers overestimate earnings forecasted above than actual earnings. This finding is consistent with recent researches’ ones and suggests information's users should be aware of Chief Executive Officers' overconfidence's negative effects on reliability of managerial forecasted information.

One of the basic goals of any society is to achieve economic growth with less fluctuations. In fact, achieving sustainable economic growth and economic stability is one of the main goals of any country. If the existing economic base and the future perspective indicate economic stabilization, the path of long-term investment growth will be strengthened, otherwise, the capital will be inclined to the service, trading and hoarding sectors, and in the long term, it will reduce the economic growth rate. In this article, the effect of macro-economic indicators (international trade, human capital, physical capital, inflation and foreign debt) and institutional indicators (combined index consisting of the components of voice and accountability, political stability without violent, government effectiveness, regulatory quality, rule of law and Corruption Control) and corruption control) on economic growth were investigated and analyzed in 15 selected developing countries during the years 2006 to 2019 with the generalized method of moments (GMM). The regression results showed that, among macroeconomic variables, inflation and foreign debts had a negative effect on economic growth, but international trade, human capital and physical capital had a positive effect on economic growth. The combined index of institutional factors also had a positive effect on economic growth.

Introduction: Given the importance of milk both in the production sector (due to job creation and income generation for activists in this field) and in demand and consumption (due to its impact on public health, etc. ) one of the important goals of government policy in the agricultural sector can be to increase the supply and demand of milk. Materials and methods: The purpose of this study is to investigate the effect of economic factors affecting milk supply in Iran based on the data collected from the provinces. The research model was estimated using the panel data approach in the form of generalized method of moments. Findings: According to the results of model estimation, milk supply in Iran is positively affected by the number of livestock and negatively affected by the cost of livestock inputs. Also, with a one-year break, milk prices and pasture area have a positive effect and meat prices have a negative effect on milk supply. Conclusion: Breeding of lactating cattle, price support, use of new animal husbandry technologies and management of livestock grazing are some of the proposed solutions to improve the milk supply in the country.

The purpose of this article is to investigate the effect of corruption on financial inclusion in Iran and selected member countries of the Organization of Islamic Cooperation during the period 2005-2020. For this purpose, three variables have been used to measure financial inclusion and three separate models were estimated. The results of model estimation using the System generalized method of moments (SGMM) showed that at a significant level of 5%, lagged financial inclusion, the level of per capita GDP and education have a positive and significant effect on financial inclusion. Also, the impact of corruption on financial inclusion is negative and significant. At a significance level of 5%, the expansion of Internet users and mobile subscribers has a positive and significant effect on financial inclusion. The high share of women in the total population has a significant and negative effect on financial inclusion. Based on the results, it is suggested that policymakers reduce the level of corruption and increase financial inclusion by reducing wide monopolies, eliminating the rent, improving the quality of regulations and creating widespread transparency.