زهرا مداحی

Study of volatility has been considered by the academics and decision makers dur-ing two last decades. First since the volatility has been a risk criterion it has been used by many decision makers and activists in capital market. Over the years it has been of more importance because of the effect of volatility on economy and capital markets stability for stocks, bonds, and foreign exchange markets. This research first deals with the evaluation of 8 various models to forecasting volatility of stock index using daily data of Tehran stock exchange. The used models include simple ones such as random walk as well as more complex models like Arch and Garch group. Forecasting volatility index method is developed in this paper. This method is based a random walk using a fuzzy logic approach. This method is used to fore-casting volatility of Iran stock exchange index. The proposed method is assessed by comparing other methods such as Moving Average, Random walk… Results show that our proposed method is compatible with existent methods.

Due to the existence of various paradigms and theories in accounting and various methods introduced to measure accounting values, as well as the lack of a complete and well-defined framework of these theories in terms of sociological paradigms, we decided to analyze sociology from theories. To achieve this goal, we used the content analysis method. In this way, first by examining the schools and theories of sociology and the main paradigm of positivism, interpretiveness, identification and components that were the characteristics of these paradigms were extracted and categorized from the themes and then the outputs were approved by sociology professors. And then accounting measurement theories and various theories using the method of taking notes from books and texts and articles extracted and sociological components in the context of accounting theories are searched and analyzed and at the end of accounting theories according to The extracted themes and their analytical codes are classified and analyzed and interpreted based on the obtained results. The results of the analysis of themes, new theories of accounting measurement tend to interpretism in which the role of the accountant is more prominent and historical cost theory is classified as a positivist sociological theory.

This study aimed to investigate the role of managers' information interpretation on cost behavior. The locative domain of this research is the companies listed in the Tehran Stock Exchange during 2014-2020 and through systematic elimination method, 112 companies have been selected as statistical sample. Managers' information interpretation is considered as an independent variable and cost behavior is considered a dependent variable. The current research is applied research, and if the classification of types of re-searches be considered based on the nature and method, the method of the present study is essentially descriptive in terms of the nature, and in terms of the method is considered in correlation researches category. In this study, library method was used to collect data. In the research data section, data was collected through collecting data of sample companies by referring to financial statements, explanatory notes and stock exchange magazine. In order to describe and summarize the data collected, the descriptive and inferential statistics are used. In order to analyze the data, variance heterogeneity pre-test, F Leimer test, Hausman test and Jarque-Bera test and then multivariate regression test were used to confirm and reject the research hypotheses (EVIEWS software). The results showed that the extent of effectiveness of managers’ information interpretation factors, including changes in managers' consensus on profit, changes in public profit information, changes in private profit information, and changes in bias in profit forecasting on cost behavior in potentially competitive conditions are different from de facto competition. The results obtained in this research are consistent with the documents mentioned in the research theoretical framework and financial literature.