It is necessary to understand the performance potential and the gap between the actual yields of crops with the achievable function so as to diagnose the limiting factors of performance. The present study has been conducted based on CPA Method in 50 fields of Zavkooh villi (Kalaleh, Golestan, Iran) in 2016 and 2017. The study has measured and recorded all information related to management practices, soil characteristics, and farmer socio-economic status. Furthermore, using stepwise regression, the Comparative Performance Analysis (CPA) Method considers the relation between the variables and yield, with the yield gap rate as well as its causes being estimated to reveal each factor’ s contribution to the creation of the yield gap. Results show that there is a 1818 kg per hectare vacuum between the average real yield (2308 kg ha-1) and the yieldable one (4123 kg ha-1), . Accordingly, the most important factors of yield gap in the region include field size (21. 4%), summer plowing (15%), the time of land preparation and plowing (14. 7%), nitrogen fertilizer (14. 6%), potassium fertilizer (14%), weed density per unit area (10. 8%), seed treatment (8. 1%), and Sub-soiler (1. 4%).

Given the importance of the rock mass rating classification system in rock engineering, the aim of this paper is to improve final classes of this classification system using k-Means and fuzzy c-Means clustering algorithms. The data classification in the rock mass rating classification system were allocated to certain classes via a set of initial information based on the opinions and judgments of experience, which the use of clustering algorithms in this system of classification, dataset were divided into specific classes after going through the stages of clustering analysis, therefore resulting in clarification of the final rock mass rating classification systems and removal of uncertainties from the linguistic criteria. Silhouette coefficient (SC) method was used for validation k-Means clustering algorithm. Furthermore, for validation of FCM clustering algorithm, four validation methods including partition distribution coefficient (PC), clustering entropy (CE), Fukuyama and Sugeno (FS) and Xie and Beni index (XB) were used. It becomes clear that due to uncertainty condition on determination of rock mass rating clustering system classes, FCM clustering algorithms yields better results than k-Means clustering algorithm. Results of data extracted from Anomaly B of Sangan iron mines indicated that the technique used in this paper is of high importance in rock mass quality.

Saffron is a very popular medicinal plant and the most expensive spice in the world. It is highly considered in traditional medicine for the treatment of varied diseases. From among Iranian agricultural crops, it is one of the most valuable products. Due to its special characteristics, its production and export can be developed. As the largest producer and exporter of saffron in the world, Iran accounts for more than 90% of global saffron production. In 2018, more than 71% of the global export of saffron belonged to Iran. Lorestan Province is becoming one of the important areas for cultivating this crop due to its natural conditions and farmers’ interest. This study tried to identify the factors affecting the sustainable development of this crop. For this purpose, during the two consecutive years of 2017 and 18, 3 regions in Kuhdasht, Kuhnani, and Khorramabad townships were selected, in which 5 sample farms were chosen based on the field research. The selected farms had a planting history of 1 to 5 years. Several quadrants were established in the farms and the phenological measurements were recorded based on them. The statistics of these farms were collected to determine the required yields. The Means and ANOVA comparisons were applied to analyze the results. The studied parameter was farm age from 1 to 5 years in the 3 regions of Kuhdasht, Kuhnani, and Khorramabad townships. In this investigation, saffron flower characteristics and dry weights of stigma were determined simultaneously with daily phenological inspections of the farms. The results in both years revealed that age was the major factor in yield change in all the 3 regions in a way that saffron yield increased with increasing farm age up to 4 years and then decreased. The effects of farm age on saffron flower and stigma yields were statistically significant. It was found that the lowest and highest yields were respectively related to the 1-, 2-, and 5-year-old farms and 3-year-old farms with a peak yield for the 4-year-old farms. During the study of the role of temperature in the two consecutive years, it was observed that the average temperature had been higher in 2017 and thus the flowering duration had decreased. Accordingly, saffron yield in this year compared to 2018 showed a smaller value, which indicated the role of temperature in yield enhancement during the flowering period. Yield differences were significant in the 3 studied regions. The highest and lowest yields were related to Kuhnani and Khorramabad farms, respectively.

The log-normal distribution is used to describe the positive data that has skewed distribution with small mean and large variance. This distribution has application in many sciences for example medicine, economics, biology and alimentary science, etc. comparison of Means of several log-normal populations always has been in focus of researchers, but their test statistics are not easy to derive or extremely complicated for this comparisons. In this paper, the size and power of different testing methods including F-test, likelihood ratio test, generalized p-value approach and computational approach test are compared in a simulation study.

Background: Laryngoscopes are the potential cause of cross-contamination between patients. A considerable way to prevent this problem is to use of disposable laryngoscope’s blades. This study was designed to evaluate laryngoscopic conditions in pediatrics with disposable and metallic Macintosh blades.Methods: 152 children scheduled for elective surgery aged 3-12 years were enrolled in this randomized clinical trial. After induction of anesthesia, anesthesiologist intubated the patients with one of two kinds of laryngoscope’s blades (disposable or metalic Macintosh). During laryngoscopy and tracheal intubation, glottic view, brightness of laryngoscopic field, time of intubation and satisfaction degree of anesthesiologist was recorded.Findings: All patients were successfully intubated. There was significant difference between disposable and metalic Macintosh blades with respect to time of intubation and brightness of laryngoscopic field. Grade I of laryngoscopy was more frequent in metalic group compared to disposable group (83% vs. 49%) Anesthesiologist satisfaction was significantly improved during laryngoscopy with metalic Macintosh blade.Conclusion: With respect to successful tracheal intubation of all patients in this trial and the usefulness of disposable laryngoscopes to prevent crosscontamination between patients and regardless of significant difference in laryngoscopic conditions between disposable and metallic blades, disposable laryngoscopes can be used under normal intubating conditions in pediatrics.