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Assessment of the role of pearls in recognizing some historical and traditional concepts governing the social and economic relations of inhabitants around the Persian Gulf, especially its central and southern coasts, is of great significance due to their special position for explaining the historical events and contexts of the Persian Gulf Region Administration. Pearl has been defined as an important commodity in the region's traditional economy, prompting researchers to explore its various social, economic, and political dimensions. Among the important historical backgrounds, recognizing and redefining how to manage this vast trade in local and regional dimensions and continuing to find traces of Iranian bureaucracy were the focus of this particular case study. With its analytical approach and based on some historical evidence, this article sought to answer the fundamental question of what the trace of Iranian bureaucracy in this process was given the mechanism of pearl fishing and trading. The prevailing premise was that bureaucracy had indirectly contributed to fishing management and regulation of pearl-fishing grounds. [ABSTRACT FROM AUTHOR]

The emergence of various intellectual ideas in the Islamic world after the death of the Prophet (PBUH) until today has posed the challenge of the convergence of the Ummah. The period of the Imamate of Imam Javad (AS) (825-842 AD) was also the season of prosperity, internal revolts, and foreign aggression against the Islamic Caliphate. The suspicious activities of these groups threatened religion. One of the threats was the division of the Ummah. The present study, by asking what the components of convergence from the perspective of Imam Javad (AS) are, seeks to identify these components in situations such as debates, confrontation with caliphs, and currents of thought. His teachings were manifested in the form of components of correcting theological beliefs with respect, lack of tension in political relations, good manners, adherence to the Holy Qur'an and tradition, and innocence from Islamic extremism. The study hypothesizes that Imam Javad (AS) considers the roots of divergence in not understanding the truth of religion, hegemony, and separatist tendencies. Imam's actions in the direction of convergence have been in the form of corrective measures in interaction with different currents, removing doubts, and avoiding any divergent action towards the unity of the Ummah. [ABSTRACT FROM AUTHOR]

Water supply at a desired rate at any time to meet the water requirements regardless of river discharge must be considered in the general design of intakes provided that the needs do not exceed the river flow. Due to the lack of necessary information in this field and the importance of sediment transport to the lateral intakes at river bends, this study aimed at understanding the mechanism of this phenomenon. To this end, the combined effect of convergence and divergence in lateral intakes on the sediment transport was investigated. According to the results, the diversion discharge to the intake was increased by converging the laboratory flume. By narrowing and converging the end of the flume, the diversion discharge was increased further, so that as the flume was converged to the size (b/B) of 0.75 and 0.5, the diversion discharge to the intake was increased by 13.6% and 75%, respectively. This could be connected to narrowing, flow obstruction and backflow to the intake. In contrast, different results were found by diverging the flume. In other words, the inflow to the intake was decreased by diverging the flume. As the flume end was diverged, the diversion discharge was decreased further. By diverging the flume to the size (b/B) of 0.75 and 0.5, the diversion discharge to the intake was decreased by 21.9 and 31.8%, respectively. The average diversion discharge to the intake at 30, 60 and 90º was 13.2, 15.2 and 11.5%, respectively. By converting the flume to the size (b/B) of 0.75 and 0.5, the diversion sediment to the intake was increased by 18.5 and 71.4%. In contrast, by diverging the flume to the size (b/B) of 0.75 and 0.5, the diversion sediment to the intake was decreased by 35.4 and 49.9%, respectively. [ABSTRACT FROM AUTHOR]

Bat Algorithm is a type of swarm intelligence algorithm which is inspired by the behavior of little bats which are looking for direction in hunting opportunities. Swarm intelligence algorithms are inspired by the nature which are very efficient on crucial optimization problems. These algorithms are simple, flexible and can be implemented easily as well. Analyzing swarm intelligence algorithms makes their utilization reliable and guarantees finding answers by them. Earlier, stability analysis has been accomplished for some swarm intelligence algorithms including Particle Swarm Optimization and Gravitational Search but sufficient mathematical analysis for the bat algorithm has not been done. For this purpose, in the present paper, we considered Bat Algorithm stability analysis using Lyapunov method. In this study, at first, stability analysis of standard bat algorithm has been analyzed. Because of unsuccessful attempts to analyze the stability of standard algorithm, new updating relations has been introduced to increase the degree of freedom. The stability analysis has been presented for these relations. Experimental results illustrate the stability of the new updating relations. [ABSTRACT FROM AUTHOR]

In this research, the frequency of the jet streams associated with extreme and pervasive precipitation has been analyzed using environmental to circulation approach. Based on the 99th percentile index, 109 days of the extreme and pervasive precipitation was selected from the IRIMO data base ( including 33 synoptic, climatic and rain gage stations during 15992 days from Farvardin, est, 1340 to Dey, 11th,1383). Jet stream frequencies and their locations have been detected over extensive area from 0° to 120° E and 0° to 80° N in four levels ( 250, 300, 400 and 500 H.Pa ) at 00:00, 06:00, 12:00 and 18:00 UTC. The results of this research indicate that except the 250 H.Pa level that jet stream at 06:00 have considerable frequency, over 300 and 400 H.Pa levels and at 18:00 they observe over study area. At the same time, the plots of average speed of jet stream in conforming with the maximum frequency of jet stream on one hand and on the other hand is simultaneous with occurring the maximum speed of jet stream over study area that indicate area have fourth quarter (positive vortices and upper divergence) which is located on the Khazar western coastal. This can result in expansion of air mass at upper level or ascending vertical motion. Generally, the elongation of jet streams mostly until 500 H.Pa level at 18:00 indicates the thickness of instability layer that can create the extreme and pervasive precipitation over Khazar western coastal. [ABSTRACT FROM AUTHOR]