درخت حوزه‌های تخصصی

Every company should think about producing new goods, the production of alternative goods is necessary in order to stabilize the level of sales or new sales; Customers also want new products, and if the company neglects to do so, competitors will certainly do so. Therefore, the present article seeks to provide a model appropriate to the conditions of gas refining companies for product development. In this study, the qualitative research method has been used as a grand theory; Using theoretical sampling and theoretical saturation, 20 experts of gas refining companies (Parsian, South Pars, Fajr Jam) were interviewed. Based on the basic theory, the data were analyzed in three stages of coding (open, axial and selective) using MAXQDA software. In the open coding phase, the data were labeled conceptually and then those that were common to each other were named into a category; the obtained categories were 43 categories. In the central coding stage, logical relationships were found between the categories and the obtained categories were included in the open coding under more general categories; finally, in the selective coding stage, all categories were summarized in one main category. The main category of the research was named "Interfering factors in new product development". The final result of this research, according to the researcher's attention and reflection on the details of the process of each of the three refining companies, is to provide an existing common model for all three companies and also to provide a common desired model for all three companies. In the open coding phase, the data was labeled conceptually and then those that were common to each other were named into a category; The obtained categories were 43 categories. In the central coding stage, logical relationships were found between the categories and the obtained categories were included in the open coding under more general categories; Finally, in the selective coding stage, all categories were summarized in one main category. The main category of the research was named "Interfering factors in new product development". The final result of this research, according to the researcher's attention and reflection on the details of the process of each of the three refining companies studied, providing a common model for all three companies and also providing a common model for all three companies.

Every company should think about producing new goods, the pAdvances in communication technology have led to changes in business practices. Shared businesses are a new way of presenting products through a platform in the virtual environment. In this business, people's assets are shared on a peer-to-peer basis. In addition to generating revenue, this business has created employment, increased productivity, reduce energy consumption and environmental pollution in the world. This study tries to investigate the barriers to the development of shared businesses in Tehran. The research method in this study is qualitative and the data collection tool is a semi-structured interview. The informed statistical population includes 30 university lecturers, elites, graduates, entrepreneurs and manufacturers. The subjects of the recorded interviews were extracted by the lecturers of the Business Management Department and analyzed using the network themes method in MAXQDA software. Findings show that 64 barriers have been identified as the basic themes and after reviewing the opinions of experts, these barriers have been classified into 6 main themes. These barriers are: trust barriers, technology barriers, knowledge and information barriers, economic barriers, political barriers and managerial barriers.

In recent decades, mentoring has been hailed as an important human resource management strategy, a career tool, and a learning activity in the workplace, and has played an important role in enhancing the positive outcomes of a high-performance work system. Therefore, the purpose of this study is to provide a model of mentoring system in the Ministry of Interior based on a mixed approach. First, based on the data theory of the foundation, 12 experts were interviewed. Sampling was done purposefully with a network of experts and continued until the theoretical saturation was reached. According to the research model, causal, pivotal, contextual, interventionist, strategic and consequences variables were identified. The results showed that mentoring will have consequences such as increasing knowledge sharing, organizational performance excellence, productivity, job satisfaction, psychological well-being, client satisfaction, increasing public trust in the organization, increasing trust in government and improving political understanding. For quantitative validation of the model and study of component relationships, the structural equation modeling approach was used using the partial least squares method using smart-PLS software. The statistical sample of this department was 237 managers and experts of the Ministry of Interior. The results of the quantitative step showed that the relationships in the model with appropriate impact coefficients were confirmed.

Studying stock options is still a pristine area of research in the Iranian capital market. This is due to the lack of data as well as the complexity of valuation methodologies. In the present paper, using the Monte-Carlo simulation, we have estimated the value of stock options traded on Tehran Stock Exchange and examined whether the use of a control variate or antithetic variate augmented methods can lower the standard error of estimates. Furthermore, the estimated values of the three models under consideration, including crude Monte-Carlo, control variates augmented Monte-Carlo, and antithetic variates augmented Monte-Carlo are compared with each other and with options market prices. The results show that the standard error of the antithetic variate method is less than the crude method and control variate method. However, the control variate augmented Monte-Carlo model is more powerful than the crude Monte-Carlo and antithetic variate augmented Monte-Carlo method. Therefore, we can conclude that the control variate augmented Monte-Carlo model has a better performance in estimating the value of trading stock options and its estimated values are closer to the market prices.

In this article, at first standard linear Black-Scholes model and then some nonlinear Black-Scholes models will be considered and thereupon alternating direction explicit (ADE) method is applied firstly for solving the standard Black-Scholes model and then for Barles and Soner model which is one of the most complete and comprehensive nonlinear Black-Scholes models. Furthermore, the stability of this method has been considered and its accuracy will be compared with other numerical methods such as finite difference methods. Since in solving nonlinear Black-Scholes models by the ADE methods, we need to solve only some scalar nonlinear equations instead of a full nonlinear system of equations that we should solve in implicit methods, so this method can be a suitable choice for solving such models.

In this paper, we present an efficient and accurate method for calculating the Black-Scholes differential equations and solve the Black-Scholes equations using Jacoby and Airfoil orthogonal bases, with the collocation method. The Black-Scholes equation is a partial differential equation, which describes the price of choice in terms of time and the collocation method is a method of deter-mining coefficients. Then we show the computational results and examine the performance of the method for the two options, the price of basic assets and its issues. These results show that the Jacoby method is more efficient in solving the Black Scholes equation, and the method error is less and the convergence rate is higher. In this paper, by applying numerical methods to the desired equation, nonlinear devices can be solved by nonlinear solution methods, such as Newton's iterative method. The existence, uniqueness of the solution, and convergence of the methods are examined, and we will show in an example that by repeating then |u n+1-u n |/|u n | <ε can be reached and this indicates the accuracy of the response to these methods.