A comprehensive statistical analysis and comparison on the characteristics of star trackers used in the world can provide valuable information to researchers, manufacturers and customers in this field. In this regard, with a comprehensive search, 12 indicators of star sensors (accuracy, maximum trackable rotation rate, acquisition time, data transmission rate, field of view, star magnitude, mass, volume, power, voltage, temperature and lifetime) among 72-star trackers has been investigated and compared in this article. Also, by fitting the curves in the comparative graphs, relationships were extracted that provide statistical design for the manufacturers. By scoring each index from 1 to 10, it is possible to compare all the characteristics of the sensors by radar charts at the same time, and it gives the satellite designers the opportunity to identify and choose the best available star sensor for their purpose and mission by weighting the criteria. Among the other features of these statistical studies is the investigation of sensors made inside the country, which shows that by taking modeling from the hardware and software of sensors such as PST3, it will be possible to upgrade and improve products in less time.

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.

In this research, evaluation of statistical methods in Predication of landslide hazard has been performed using data Processed by Geographic Information System (GIS). For this purpose, Rudbar area as an appropriate example for north part of the Iran was selected.Our investigation indicates that lithology distance from faults, vegetation cover, land use, rain fall, and maximum acceleration rate are the main landslide controlling factors in the area. Each of these factors was used as a thematic layer for landslide hazard zonation mapping.Univariate and multivariate statistical analysis were used for landslide hazard analysis. Regression analysis indicates that classification of each parameter map into a number of relavant calsses such as slope, rainfall, . . . reduces accuracy of prediction. Also weighting of samples based on area of each unit and landslide occurrence increase accurracy.In general, among univariate statistical analaysis, area density method represents better results. Multivariate analysis indicates appropriate results for continous data compared to discrete data. On the other hand weighting of samples based on values such as area of ground units or percentage of landslide in each unite improves the results.

A B S T R A C T Green city is one of the approaches to sustainable development. “green city” is an environmentally friendly city compatible with the concept of sustainable development and can be used for the welfare and security of its inhabitants. Based on the concept of a “green city,” urban managers try to have the least destructive effect on the ecosystems upon which cities rely. Green city is one of the sustainable development approaches that reduce the environmental footprint of cities. The purpose of this study is to evaluate the situation of Mashhad metropolis in terms of the objective characteristics of the green city. In this study, 14 indicators of electricity consumption per capita, green space per capita, population density, water availability, sewage availability, superior public transportation network, urban mass transportation, traffic reduction, annual production waste per capita, carbon monoxide, concentration nitrogen dioxide, sulfur dioxide concentration, particulate matter concentration, and air quality were exerted. To determine the importance of research indicators, the Shannon entropy method, and the status of Mashhad city areas in terms of green city indicators, the VIKOR multi-criteria decision-making method has been applied. The results showed that most areas of Mashhad are average and below average in terms of green city characteristics, and only District 9 is in very good condition (0.636). Also, based on the results of this part of the research, District 5, with the value of VIKOR index of 0.969, is in the last rank in terms of objective characteristics of the green city Extended Abstract Introduction Green city is one of the approaches to sustainable development. A “Green city” is an environmentally friendly city compatible with the concept of sustainable development and can be used for the welfare and security of its inhabitants. Based on the concept of a “green city,” urban managers try to have the least destructive effect on the ecosystems upon which cities rely. Green cities constantly try to manage their environmental effects by reducing waste, increasing recycling, reducing air pollution, increasing population density, developing open urban spaces, and encouraging the development of sustainable local businesses. Green cities were first used to evaluate 30 European cities by the Economist Intelligence Unit (EIU) in 2009 with the financial support of Siemens and the aim of reducing the environmental effects of human activities in cities. In that study, eight indices of carbon dioxide, energy, construction, transportation, water, recycling and land use, air quality, and environmental governance were used. Later, the Economist Intelligence Unit, with the financial support of Siemens, evaluated the status of the green city index in 17 Latin American cities, 15 African cities, 22 major Asian cities, and 27 cities in United States, Canada, Australia, and New Zealand. In recent years, even some Western Islamic scholars have, in various publications, shown that Islam is an ecological religion. In Iran, the issue of protecting the environment has not received much attention regardless of its rich cultural and religious background and its confirmation in Article 50 of the Constitution of the Islamic Republic of Iran. Mashhad is the second metropolis of Iran, located in North-East of Iran, and is one of the counties of Khorasan Razavi Province. According to the 2016 Iranian Population and Housing Census, its population was 3057679 people (The Vice-Presidency of Planning and Development of Mashhad Municipality). In Mashhad, due to several reasons including the presence of Imam Reza Shrine (PBUH) and arrival of millions of pilgrims per year, population growth, increased garbage production (production of 896534 tons of garbage in 2016 (The Vice-Presidency of Planning and Development of Mashhad Municipality), air pollution (increased number of unhealthy days from 46 days per year in 2015 to 88 days in 2016 for sensitive groups and 4 days of unhealthy air for all groups in 2016 (Center for Monitoring Environmental Pollutants of Mashhad Municipality) the 2025 vision of the city has paid attention to the environment in the form of five general objectives; however, just like the national level, no specific pattern for environmentally-compatible urban development, such as green city, is determined. Analysis of the green city index in Mashhad metropolis can considerably contribute to urban managers and planners in addition to providing a pattern for evaluating the present situation in other cities of Iran and improving the quality of life regardless of the current status of the urban environment in Iranian cities; we can preserve these environments as parts of the natural environment for future generations.   Methodology In terms of its goal, the present study is an applied one; in the study, drawing upon other studies and library sources and considering the conditions of Iran and the metropolis of Mashhad in terms of green city, 14 quantitative indices were exerted. To this end, the required data for the quantitative indices was gathered by library research from the relevant institutions. Next, the weights of quantitative indices were determined using Shannon's entropy. Then, using the VIKOR method of multi-criteria decision-making, the status of various districts of the metropolis of Mashhad in terms of quantitative indices of green city was determined. Finally, the map of the spatial distribution of quantitative indices was drawn using the ARC GIS software package.   Results and discussion In this study, to analyze the status of the metropolis of Mashhad in terms of green city features, 14 quantitative indices were used. Considering the value of the VIKOR index ranges from 0 to 1, various districts of Mashhad can be classified into five categories; very satisfactory, satisfactory, average, unsatisfactory, and very unsatisfactory in terms of quantitative indices of green city. The results of the current situation of Mashhad showed that in terms of objective indicators of the green city, District 9 of Mashhad metropolis with a value of VIKOR index of 0.056 is in first place, and the seventh region with a value of VIKOR index of 0.433 is in second place. Also, based on the results of this part of the research, District 5, with the value of VIKOR index of 0.969, is in the last rank in terms of objective characteristics of the green city.   Conclusion Similarly, the results of studies by Afshar (2011) and Shabani et al. (2017) on Tehran metropolis are indicative of the unsatisfactory situation of Tehran (the biggest metropolis of Iran) in terms of green city features. Comparing the results of the studies by Afshar (2011) and Shabani et al. (2017) with the present study on Mashhad (the second biggest metropolis of Iran) reveals the necessity for a comprehensive plan toward achieving green cities. It should be mentioned that, due to the specific conditions of Mashhad metropolis and availability or unavailability of the required data, the indices used in the present study are somewhat different from the ones used by Afshar (2011) and Shabani et al. (2017).   Funding There is no funding support.   Authors’ Contribution All of the authors approved the content of the manuscript and agreed on all aspects of the work.     Conflict of Interest Authors declared no conflict of interest.   Acknowledgments We are grateful to all the scientific

Despite the identification of crash hotspots as a first step of the roads safety management process, with various effective black spots identification (HSID) methods, only a few researchers have compared the performance of these methods; also it is not clear which test is the most consistent in the black-spots identification. In this research, seven commonly applied HSID methods (accident frequency (AF), PIARC coefficient based equivalent property damage only (EPDO), P-value (Islamic Republic of Iran Ministry Roads and Urban development), accident rate (AR), combined criteria, empirical Bayes (EB), societal risk-based) were compared against six robust and informative quantitative evaluation criteria (site consistency test, method consistency test, total rank differences test, total score test, sensitivity test and specificity test). These tests evaluate each method performance in a variety of areas, such as efficiency in identifying sites that show consistently poor safety performance, reliability in identifying the same black spots in subsequent time periods. To evaluate the HSID methods, three years of crash data from the Kerman state were used. Analytical Hierarchy Process (AHP) method has been used for determination the importance coefficients of evaluation tests and as a result, showed that the total rank differences test is the most appropriate test. The quantitative evaluation tests showed that the EB method performs better than the other HSID method. Test results highlight that the EB method is the most consistent and reliable method for identifying priority investigation locations. Overall, this result is consistent with the results of previous studies. The societal risk-based method performed worst in the all of the tests. It should be noted that advantages associated with the EB method were based on crash data from one of the road in Iran country, so the relative performances of HSID methods may change when using other crash data. However, the study results are consistent with earlier findings.

Up to now, no complete study was carried out about the prevalence and location of periapical granuloma and radicular cysts from the point of view of clinical symptoms (e.g. pain and swelling fistula) in Iran. The data was collected from the files available in the Department of Pathology, faculty of Dentistry, Tehran University of Medical Sciences. With a consideration on different therapeutic methods, a proper method was selected. Radicular cyst occurred in 59.3 percent of 324 cases while 45.7 percent were granuloma. The most common incidence of these lesions was in the range of 24-25 years old. The most common location of lesions was the maxillary anterior. Sinus tracts occurred in 74 of all cases. 47.3 percent of these patients have been previously received root canal therapy. It is noticeable that 24 percent of all patients were treated endodontically before surgery. Higher incidence of granuloma occurred in small lesions while cysts were more common in large lesions. 232 of all cases showed one of the clinical symptoms, 16% pain, 35.8% swelling and 22.8% fistula. No symptoms were found in 92 cases.

Background and Purpose: Development in sciences are influenced by the wys of comfort in living today. But, the development has provided high problems such as environmental pollution. Heavy metals are the most important elements that contaminated environment and are poisonous for human as well. These elements such as Pb, Zn, Cr, Cd, Co and Cu are produced by industrial activities. Method: This paper attempts to apply geochemical methods such as statistical and geostatistical method for evaluation of distribution heavy metals in soils. Thermal power plant of Shazand in the close of Mohajaran of Arak city is the center of elemental pollution accompanied with refinery and petrochemical in this area. Findings: This study is determined that among the elements such as Pb, Zn, Cr, Cd, Co and Cu, only Cd is contaminants element. Discussion and Conclusion: The amount of Cd is high in fuel raw of Iran and Shazand power plant uses this fuel. Therefore, Cd has increased in the extruded smok and has transferred by wind and has deposited in the soil.