Symbol Rate is one of the key values that a receiver needs to know to find out the information contained in the received signal. In situations where the receiver is not aware of this value, it is necessary to use an Estimation algorithm to achieve the goal. The subject of this article is "Symbol Rate Estimation in frequency selective multi path channels" that is more complicated than the Gaussian channel. In this article, after studying some of available sources and methods in this field, an algorithm is proposed to estimate the Symbol Rate in frequency selective multi path channel. The performance of the proposed algorithm has been discussed in the HF and LTE frequency selective channels with bursts contained of 100 Symbols. The curves that considered to determine the performance of the algorithm are the percentage of correct Estimation and the NMSE graphs. for the channels which the estimator's performance is measured, in the SNR equal to zero decibels, percentage of correct Estimation is more than 95% and the NMSE of Estimations is almost 0. 001.

Modulation recognition and Symbol duration Estimation is the first step towards the exploration of the electromagnetic signals transmitted in electronic battlefields. One of the simplest procedures for blind Symbol duration Estimation of digitally modulated signals is done by analysis of zero-crossings of the key signal features, which are instantaneous frequency, phase, and amplitude. In this paper, a modified algorithm based on previous works is proposed for Estimation of digital modulations Symbol duration. The performance of the proposed algorithm is evaluated in the presence of carrier frequency offset and as the simulation results indicate, the performance of the modified algorithm is much better than the classic algorithm. As it is expected and it is shown, the robustness of this method for amplitude or frequency modulation is more than the robustness for phase modulation.

In prominent mystical texts, including the works of Rūmī and 'Attār, Mahmūd appears as a Symbol of the destination and the purpose. In this paper, the writer; examining this Symbol in the works of the great Iranian mystics, explores the reason why the Symbol is so well-known in the history and culture of Iran.  

This paper estimates a social discount Rate for Iran for the purpose of economic evaluation of investment projects such as those aimed at improving the nation's welfare. The component parameters of this Rate are, the growth Rate of per capital consumption in real term, the elasticity of the marginal utility of consumption and mortality-based discount Rate. Based upon time series data the overall figure out of be %7.2, that appears to be reasonable and thus may be used in cost-benefit analysis in the country.

The effect of exchange Rate change on prices, which is known as exchange Rate pass-through in economic literature, has been one of the important factors of inflationary pressures in Iran's economy. In order to estimate the degree of exchange Rate pass-through, a vector error correction model for Iran's macroeconomics with two long run structural relationships including the long run price relationship and the long run real production relationship. Considering that during the recent decades, Iran's economy has mainly witnessed the multiple exchange Rate system, the Estimation of the exchange Rate pass-through based solely on the unofficial exchange Rate and without considering the preferential Rates cannot be relied upon. For this reason, the estimated model includes three exchange Rates (the unofficial exchange Rate, and tow preferential exchange Rate (Nima and Mobadele) to exchange Rate pass-through can be estimated sepaRately for each Rate. The results indicate that the degree of exchange Rate pass-through for the preferential exchange Rates (Mobadele and Nima) in the long run (six years) is equal to 8/9% and 8/4% and in the case of fixing preferential Rates, the degree of exchange Rate pass-through will decrease from 2/46% to 6/30%. The results also indicate that although the fixing of preferential exchange Rates leads to a decrease in the degree of exchange Rate pass-through during the stabilization period, but it will increase in the same proportion during the adjustment period of the preferential exchange Rates.

In this article, an attempt has been made to estimate the amount of sound transmission loss in a flat oval channel by applying the approach of statistical energy analysis. Correct Estimation of sound transmission loss in an air conditioning channel is of great importance due to the harmful effects of noise pollution in the environment on human health. Simulation with the statistical energy analysis method is a powerful approach to estimate sound and vibration in problems in which we deal with complex and multi-part systems; is considered. In this method, first, a system is divided into several subsystems, and then by writing a matrix equation that includes the energy exchanges between subsystems and energy loss coefficients; It is investigated from the perspective of vibration and sound Estimation.On average, the model presented in this research is able to estimate the sound transmission loss in different dimensions of the air conditioning channels according to the experimental results in the accuracy range of ± 2.5 dB. Considering that it seems that the results obtained from modeling with this method are in good agreement with the experimental data; The results of this research can be used as an efficient approach to estimate noise in oval shaped channels stretched in different lengths.

This article examines factors that affect the Real Permanent Equilibrium Exchange Rate and determines the degree of deviation of the informal market exchange Rate from it. For this study, a Dynamic Ordinary Least Square Model is applied for the period of 1369Q: 1-1399Q: 4. According to the research findings, increasing net ratio of foreign assets of the central bank to production, productivity and also the ratio of trade surplus to production, lead to a decrease in the real Permanent Equilibrium Exchange Rate and increasing ratio of expenditures government to production leads to an increase in it. Also, calculations show that since 1397, the upward trend of the Permanent Equilibrium Exchange Rate has started and since then until the end of 1399, the currency deviation in the country has always been positive. One of the most critical seasons in this period was the third quarter of 1399, in which the currency deviation has exceeded 32%. According to the forecasts made based on the estimated model, with the scenario of the continuation of the current situation, the equilibrium exchange Rate of the summer of 1400 has been estimated at more than 25 thousand Tomans.

Purpose: This research aimed at estimating the patient effective dose from digital radiography repeat Rateand evaluating the factors that contribute to the repetition of radiographic procedures in two referral hospitals in Sari, Iran. Materials and Methods: Entrance skin dose and effective dose per common radiography procedures in digital radiography were measured. 1724 X-ray exposures were investigated prospectively. The annual number of each radiography procedure was obtained from the archives of the digital radiography department. The patient cumulative dose was the calculation from annual exposures Repeat Rate (RR) and effective dose per digital radiography procedures. Results: The mean exposure RR per examination was 1. 12% and the total percentage of a repeat of all examination was 8. 9%. Annual cumulative dose (man-mSivert) resulted from radiographic RR was 449. 2. The chest and lumbar spine radiography had the highest annual number and the highest radiation dose, respectively; therefore, these procedures transfer the largest annual dose from repeated radiographic images to the patients. The factors leading to the repetition included the radiographer error (69%), the X-ray tube and equipment error (10. 4%), the patient related error (16. 1%) and other cases (4. 1%). The average effective dose for each examination was 0. 36 mSv. Conclusion: Digital radiographic repeat Rate increases a 1. 1 % annual patient effective dose from the base level that receives from the current radiographic examination. Inconsistency of the center of the digital panel and the central axis of the X-ray beam and error in the selection of the upright or table digital panel are among the most important factors in the repetition of digital radiography.