درخت حوزه‌های تخصصی

Finding the best way to optimize the portfolio after Markowitz's 1952 article has always been and will continue to be one of the concerns of activists in the investment management industry. Researchers have come up with different solutions to overcome this problem. The introduction of mathematical models and meta-heuristic models is one of the activities that has influenced portfolio optimization in recent decades. Along with the growing use of portfolios and despite its rich literature, there are still many unanswered issues and questions in this area. Also, Iranian capital markets, as emerging markets, require native research to answer these questions and issues. The purpose of this study is to provide a useful and effective tool to assist professionals and researchers in portfolio selection theory. This study, while comprehensively reviewing the literature on the subject and the developments and expansions made in the area of portfolio selection and optimization, reviews the types of problems and optimization methods.

According to the domestic studies conducted on in the field of internal controls, the gap of providing models for identifying weak internal controls is felt completely. The present study is aimed at providing a model for assessing the quality of internal controls based on the characteristics of the economic unit, the characteristics of auditor as well as their expected goals in the Firm's listed in Tehran Stock Exchange. This model is designed according to quantitative criteria. To achieve the research’s goal, 86 Firm's from all Firm's accepted in Tehran Stock Exchange for the period 2012-2017 were selected and the research hypothesis was tested using the combined data approach. Given the research hypothesis that points out that the internal assessment model based on the characteristics of the economic units, the characteristics of auditor and their expected objectives may more accurately assess the quality of the internal controls, according to the significance level of less than 0.05, the independent variables indicate a significant relationship between the internal controls assessment model based on the characteristics of the economic units, the characteristics of auditor and their expected objectives as well as the weaknesses of the internal control of the Firm. Furthermore, the estimated coefficient of the control variables of the research indicates a significant relationship between these variables and the weaknesses of the internal controls.

Sustainability is a wide concept that contains other concepts such as social responsibility and has been investigated with concepts such as competition sustainability, reporting sustainability, and social sustainability. The present study aims to investigate the role of social interest rate risk management (SIRRM) in the relationship between sustainability performance and investment efficiency. In terms of purpose, this study is an applied one, and form the methodological point of view is a descriptive correlational study. Accordingly, the required data has been collected from 79 listed firms on Tehran Stock Exchange during 2013-2017. In this research, social risk management includes SIRRM, and sustainability performance includes sustainability of reporting, competition, and ownership. The results indicate that SIRRM reinforces the relationship between competition sustainability, reporting sustainability, and ownership sustainability with investment efficiency.