درخت حوزه‌های تخصصی

This study, attempts to estimate and compare four different models of jump-diffusion class combined with stochastic volatility that are based on stochastic differential equations, and their parameters latent variables are estimated by Markov chain Monte Carlo (MCMC) methods. In the Stochastic Volatility with Correlated Jumps (SVCJ) model, volatilities are scholastic, and the term jump is added to both scholastic prices and volatilities. The results of this study showed that this model is more efficient than the others are, as it provides a significantly better fit to the data, and therefore, corrects the shortcomings of the previous models and that it is closer to the actual market prices. Therefore, our estimating model under the Monte Carlo simulation allows an analysis on oil prices during certain times in the periods of tension and shock in the oil market

The issue of proper career path development is important according to the knowledge management model for employees in many risky businesses in the country, especially since the outbreak of coronavirus and international sanctions against our country, so this study aims to design a model of progress. The career path was based on the knowledge management model in start-up businesses. The statistical population studied in this study consists of 877 people working in new businesses. Statistical sample size 269 people were selected through random sampling method. For statistical analysis, SPSS software version 20 and pls3 were used and the alpha level was considered 05p 05 0.05. The results showed that the value of t in all paths between the research factors is equal to and greater than 2.58. As a result, there is a significant relationship between the main factors and their sub-factors in the conceptual-analytical model of the research and also the results showed that the fit of the general research model is appropriate and strong. In general, it can be said that between the first step of the career path with the second step of the career path, between the second step of the career path with the third step of the career path and between the third step of the career path with the fourth step of the career path of employees There is a direct and significant relationship between start-up business employees in the conceptual-analytical model of career path.

The present research identifies and prioritizes the effective organizational structure components using content (theme) analysis and Delphi technique and hierarchical analysis (Case Study of Regional Electric Companies of Iran). The present study is applied  based on purpose and is exploratory-survey based on the nature and method of data collection. The statistical population of this study includes 36 experts selected from Iranian regional electricity companies. They were identified through targeted sampling. To analyze the research data, statistical software MAXQDA2012, SPSS and EXPERT CHOICE were used. Using these statistical software, in order to test research questions, Kendall test have been investigated. In the qualitative phase, we analyzed and interpreted (coding) of concepts expressed by the experts of the regional electricity companies of Iran, including open, axial and selective coding. The Delphi method was then used to localize and screen the indices obtained. In the content (theme) analysis phase, 20 factors were identified and after gathering the experts 'responses in Delphi periods, the members' concordance was assessed through SPSS software and by calculating the Kendall's coefficient of concordance for the questionnaires, and the investigation and concordance among the experts was obtained 81.9%. The results showed that 15 components were agreed upon by the experts. In the final step, the components were prioritized using the hierarchical analysis approach. The results of the hierarchical analysis showed that among the criteria, the complexity criterion was of the highest importance. The next priorities from the experts' point of view are the inhibitor or developer factors and the technology criterion.