a. souri

One of the important issues that has attracted the attention of economists over the past decades is the role of financial systems in the economic growth of countries. Insurance industry is one significant component of financial markets. Therefore, the stability and efficiency of insurance industry as a financial market sector is important for a country's economy. One of the most crucial changes in Iran's insurance industry is the regulations having been made in recent years. One main goal of regulation is to eliminate problems of market failure and improve efficiency. This research investigates the effect of these regulations on the efficiency of insurance companies in Iran.

The studied community is 27 insurance companies in the country and the relevant statistics were collected for the years 1385-1400 Persian Year (2005-2020). This study was conducted in two stages. In the first stage, the efficiency of insurance companies has been measured, using the method of data envelopment analysis (DEA) with the bootstrap approach. The implicit assumption of the traditional data envelopment analysis method is that the inputs and outputs are definite. But the output of an insurer is not necessarily certain. To solve this problem, we can use the bootstrap approach to obtain statistical characteristics for this technique. In the second stage, in order to investigate the effect of regulation on efficiency, according to the reviewed studies, the purpose of the present study, and the conditions of Iran's insurance industry, the effective factors on efficiency are determined and the regression model is defined. Then, the dynamic regression model was estimated using the generalized method of moments (GMM) and the related tests confirmed the validity of the results of the model. To calculate the efficiency and estimation of the model, MATLAB and Eviews software were used.

The most important finding of the research is the significant effect of regulation on efficiency. Also the coefficient of regulation, market share, and privateness of insurance companies are estimated as -0.066, 0.041 and 0.306 respectively.

The results of the research show that regulation had a negative effect on the efficiency of insurers and led to a decrease in their efficiency, but the market share and the privateness of insurance companies had a positive effect on the efficiency. In the end, suggestions for improving the efficiency of insurers have been presented.

Today, a growing number of the world population faces a rise in the cost of living significantly increased energy costs. That is why Energy-saving has become a vital issue. One of the remarkable ways to reduce energy consumption is using cool pigments; therefore, research has been done to improve pigments' infrared reflection capability. In this paper, the role of particle morphology was investigated to boost the infrared reflection property of iron-chromium-based pigments. For this purpose, a series of inorganic pigments based on the Fe0.7Cr1.3O3 formula was prepared via a hydrothermal method. Surfactants altered the particles' morphology to improve the pigments' reflecting properties. According to the IR reflectance results, flaky particles exhibit an enhanced IR reflection, and they have significantly larger IR reflections than spherical particles. Furthermore, the results have revealed that silica coating leads to a meaningful improvement in the IR reflection property. It was found that the maximum near-infrared solar reflectance of the sample with 2.63 % succinic acid surfactant and silica coating was 52.23 % compared to that of Fe0.7Cr1.3O3, which was 25.36 %.

In this paper, we discussed the application of a compositional adaptation approach to recommend learning resources to users in the area of software development.  This approach makes use of a domain-specific ontology in this area to find those words, which are used in the technical description of the stored cases. A point peculiar with representing cases in the proposed approach is to take into account the characteristics of included learning resources, which justify the way they support the essential operations in the case of solution. In this way, only those components that comply with user’s request would be considered in the final solution. In the paper, the performance of the proposed approach for recommending learning resources together with the status of user experience in his/ her interaction with the resulted recommending system, have been evaluated. Results demonstrate the fact that the learning resources through this approach are sufficiently beneficial for the users. Although the proposed approach has been applied for recommending learning resources in the area of software development, it can be equally applied to any technological area through developing domain-specific ontology for that area. This is mainly because any technological area has its own specific objects/ entities holding their own semantic similarities that finally lead to forming a domain-specific ontology for that area.

Increasing the thickness of the oxide layer on the surface of the titanium alloy by electrochemical processes such as anodizing, leads to improved corrosion resistance and ultimately increase the lifespan of titanium implants in the human body. Among the parameters affecting the properties of the anodized layer, process voltage is of great importance with respect to kinetic and thermodynamic processes. In this paper, titanium substrate is subjected to anodizing process in sulfuric acid solution by different voltages such as 3, 6, 9 and 21 volts, electrolyte temperature of 60 ° C and duration of 30 seconds. Then the fuzzy, structural and morphological behavior, as well as the corrosion behavior of the coating are evaluated by GIXRD, FESEM and electrochemical tests such as electrochemical impedance in the simulated body fluid (SBF) solutionat 37 °C, respectively. GIXRD and FESEM analyzes show the formation of a titanium oxide coating with a hexagonal structure, which with increasing voltage up to 6 volts, a smoother and smoother surface was obtained, but further increase of voltage up to 9 and 21 volts, resulted in a rougher surface. Also, the results of corrosion behavior showed that increasing the anodizing voltage up to 6 volts due to the presence of a more uniform and smoother surface, which indicates less surface imperfections, led to the highest load transfer resistance in 1 and 24 hours of immersion in SBF solution at 37354 And 58127 (Ω .Cm2 ) compared to other anodized samples.

Generally, Rayleigh damping assumes a specified damping ratio for the structure in the dynamic analysis. Although this assumption is accepted in analysis and design of structures, there is some distance from the experimental results showing that the damping ratio depends on the stress amplitude. In this paper, the damping ratio for each element is a function of its principal stress and its value is determined utilizing a proposed algorithm called Element Developed Energy Dissipation Algorithm (EDEDA). The proposed algorithm was implemented into a code based on finite element, which is able to simulate nonlinear behavior of mass concrete utilizing the smeared crack approach. In this regard, due to stress redistribution in the nonlinear time history analysis, we have a new concept, namely damping ratio redistribution such that when the stress value of each element changes, the relevant damping value is updated. Based on an analysis of a typical concrete gravity dam (Pine Flat dam), two usual methods in the Rayleigh damping approach which include stiffness proportional damping and mass/stiffness proportional damping are considered rigorously. In addition, the brittle damping approach was utilized in the proposed algorithm, where the damping contribution of a cracked element was eliminated from the computing procedure. It was found that when the damping redistribution was taken into account, the damping ratio in each element would be updated at each time step corresponding to the principal stress. This algorithm would produce more real results about the considered gravity dam so that in the low-level seismic excitation, the response of the structure was less than that in the traditional method and raising the excitation level led to higher damping affecting the crest displacement. In addition, the stiffness proportional damping leads to crack profiles in the neck region of the dam body showing more correspondence than the results obtained from the models with mass/stiffness proportional damping.

The main goal of this study is to compare emotional self-efficacy, self-regulation learning strategies and motivational beliefs in the students. The design of this study was a causal-comparative study. The statistical population in this study included all female secondary school students in the 3rd district of Tehran. Among the statistical population of this study, 120 people were selected through a multistage cluster random sampling method. Multivariate analysis of variance was used to analyze the research data. The results showed that there is a significant difference between emotional self-efficacy, self-regulated learning strategies (cognitive and metacognitive) and motivational beliefs (self-efficacy, internal evaluation and test anxiety) in excellent and non-excellent students (P <0.01). In the field of the three studied variables, superiority with students is excellent. Therefore, it can be concluded that there is a significant difference between these two groups in terms of emotional self-efficacy, self-regulatory learning strategies and motivational beliefs. Therefore, providing appropriate conditions for the development of emotional self-efficacy and motivational beliefs and teaching self-regulated learning strategies can provide more opportunities for students to progress and learn.

In this paper, CAZO and CZO thin films were deposited on quartz substrates by radio frequency magnetic sputtering and annealed at different temperatures of 400, 500, and 600°C. One of the most structural studies of thin-film materials is the analysis of the results that are obtained from AFM images. The most variations in optical density of CZO and CAZO thin films were at energy points to about 3eV and 4eV, respectively. Fractal dimensions and structural properties of films, as well as the optical density of CZO and CAZO thin films, were investigated. The AFM images were used to estimate the lateral size of the nanoparticles on the surface of the films. Annealed films at 500°Chad the maximum values for the lateral size of the nanoparticles. These values for the as-deposited films and annealed films at different temperatures of 400, 500, and 600°C were about 7.9,8.1, 6.5, and 7.75nm for CZO thin films, respectively. In addition, the lateral size of CAZO thin films was about 6.8, 6.27, 6.04, and 6.71, respectively. Films that annealed at 500°Chad the minimum value of fractal dimensions. The power spectral density of all films reflects the inverse power low variations, especially in the high spatial frequency region, indicating the presence of fractal components in prominent topographies. The maximum variations in the bearing area were as much as 0.015μm and 0.01μm for CZO thin films and CAZO thin films, respectively.

The aim of this study was to investigate the relationship between family-social factors and substance use through the mediating role of the components of temperament, character, psychological capital, and beliefs. A descriptive-correlational research method was employed for the conduct of this study. All the 18-35-year-old male substance users in Qom who had presented to addiction treatment camps and Qom addiction centers in 2017 and 2018 constituted the statistical population of the present study. From among this population, the number of 320 participants was selected via convenience sampling method. Mohammadkhani's High-Risk Behaviors Questionnaire for Adults, Scale of Effective Factors in Drug Abuse Tendency among Youth, Cloninger's Temperament and Character Inventory (TCI), and Luthans Psychosocial Capital Questionnaire were the measurement instruments used for data collection in this study. The proposed model was evaluated using Confirmatory Factor Analysis (CFA) and Structural Equation Modeling (SEM) in Amos software. The model was revealed to enjoy desired fitness indices. Family had indirect effects on substance use through positive attitudes towards substances, self-directiveness, and resiliency. Friends had indirect effects on substance use through positive attitudes toward substances, harm avoidance, and self-directiveness. The market of substances indirectly affected substance use through the mediation of positive attitudes towards substance use. Moreover, positive attitudes towards substance use and high levels of harm avoidance had a direct and positive impact on substance use; and low levels of self-directiveness and resiliency had a direct negative effect on substance sue. From among the exogenous variables, friends with the coefficient of 0.303 had the highest indirect effect on substance use; and from among the mediating variables, harm avoidance with the coefficient of 0.782 had the highest direct impact on substance use. The current findings were in line with those of similar prior studies and are considered an important step to explain the factors affecting substance use. The present findings can also be regarded as a model for the design of comprehensive prevention programs for high-risk behaviors.

In arid and semi-arid regions of Iran as the rainfall is reduced and the population and the demand for food continue to grow, high-quality water consumption and the development of planting area increasingly gain importance. The present study was aimed to evaluate the economic benefits of the pressurized irrigation system in Ardabil Province, Iran by a survey methodology, production function, and farmers’ data for the growing season 2014-2015 (using a questionnaire). Results show that pressurized irrigation system not only reduces water consumption by as high as 17%, but it also optimizes the application of other production inputs and enhances the productivity of production inputs and water.