درخت حوزه‌های تخصصی

The gaining returns in line with risks is always a major concern for market play-ers. This study compared the selection of stock portfolios based on the strategy of buying and retaining winning stocks and the purchase strategy based on the level of investment risks. In this study, the two-step optimization algorithms NSGA-II and SPEA-II were used to optimize the stock portfolios. In order to determine the winning algorithm, the performance indexes, Set coverage and the Mean Ideal Distance were used. Finally, the active shares of 50 Tehran Stock Exchange com-panies were analysed (2007-2016). The results indicate that the SPEA-II algo-rithm can perform optimization and achieve a better performance than the NSGA-II. This algorithm could achieve better outcomes than the winning strategy during the selection period based on the risk-taking strategies in different months

Fraudulent financial reporting has been one of the most sensitive issues on the business world. Financial statements that conceal the company's facts have caused great losses to its stakeholders. The ranking of companies based on fraudulent financial reporting is one of the key issues for performance analysis. This study, by using financial variables and the data envelopment analysis methodology, ranked the pharmaceutical companies listed on the Tehran Stock Exchange in terms of fraudulent financial reporting. The data and theoretical framework of the research are based on library studies and data analysis has been done based on the data envelopment analysis model. The results of this study indicate that the most manipulation of profits in 2015 was in the Daru Amin and Faravordehaye Tazrighi companies, as well as Iran Daru and Sina Daru in 2016. This will lead to the companies being ranked at the highest level of fraudulent financial reporting.

The high transparency and ability of consumers to transmit advertising content quickly in the modern age require that organizations consider authenticity and interaction with customers among their top priorities and combine consumer-generated advertising (CGA) with their own marketing strategies in order to respond to these priorities. This study aims to investigate the factors affecting consumers' attitudes and willingness toward consumer-generated advertising and its effect on brand loyalty and attachment. This is an applied study conducted using the descriptive correlational survey method. Its statistical population consists of dairy consumers of Kalleh Company in Mazandaran Province. A total of 460 questionnaires were distributed by stratified random sampling and descriptive and inferential statistics was used for data analysis. Structural equation modeling and Smart PLS2 were used to test the hypotheses. The reliability of the questionnaires was determined by Cronbach's alpha test and composite reliability coefficient. Results showed that brand attachment had a significant positive effect on attitude toward advertising production and willingness to participate in advertising production. Attitude toward advertising production has a significant positive effect on willingness toward CGA as well as on brand loyalty. It was also shown that brand attachment has a significant positive effect on loyalty. The rapid changes in technology and the development of effective advertising in the modern businesses require defining the concept of CGA, which is addressed in the present study. Also, based on the results of this study, brand attachment increases customers’ willingness toward and participation in CGA. An increase in customers' willingness and involvement in advertising production will also increase their loyalty.