درخت حوزه‌های تخصصی

The goal of investors in forming a stock portfolio is to obtain the highest return for bearing the lowest risk and portfolio optimization is one of the most complicated problems in the field of finance and investment. It is an NP-hard problem, and in general there is no definite method in polynomial time to find an exact solution for it. In this research, to solve the problem of choosing the optimal stock portfolio, the multi-criteria decision making method has been used under conditions of uncertainty. In order to implement the algorithm and evaluate it, the monthly returns of the Tehran Stock Exchange indices were used between 2018 and 2013. The results can be examined from two different perspectives. From an analytical and technical point of view, the results can be discussed. From a technical point of view, presenting a new technique for doing things can give the capital market participants the confidence that they can choose a stock portfolio using a new tool. From an analytical point of view, the existence of decision making algorithms in providing the optimal portfolio is a new step that can be used in the combination of fundamental analysis and the use of dynamic stock portfolio.

This study aimed to examine the predictive role of frustration tolerance and social competence in body image satisfaction among adolescents with physical disabilities. This research utilized a correlational descriptive design with a sample of 350 adolescents with physical disabilities, selected based on Morgan and Krejcie’s sample size determination table. Participants completed standardized self-report measures assessing body image satisfaction (MBSRQ), frustration tolerance (FDS), and social competence (SSRS). Data analysis was conducted using Pearson correlation to explore associations between variables and linear regression to determine the predictive power of frustration tolerance and social competence on body image satisfaction. All statistical analyses were performed using SPSS-27, and assumptions of normality, linearity, and multicollinearity were confirmed before conducting the regression analysis. Descriptive statistics showed that participants had a mean body image satisfaction score of 74.56 (SD = 9.87), a frustration tolerance score of 62.34 (SD = 8.23), and a social competence score of 68.21 (SD = 7.95). Correlation analysis revealed significant positive relationships between body image satisfaction and frustration tolerance (r = 0.52, p < 0.01) and body image satisfaction and social competence (r = 0.61, p < 0.01). The regression model was statistically significant (F(2, 347) = 90.75, p < 0.01, R² = 0.46), indicating that frustration tolerance (B = 0.42, β = 0.39, t = 5.25, p < 0.01) and social competence (B = 0.56, β = 0.47, t = 7.91, p < 0.01) were both significant predictors of body image satisfaction. The findings suggest that higher frustration tolerance and greater social competence are associated with increased body image satisfaction in adolescents with physical disabilities, with social competence playing a slightly stronger role. These results highlight the importance of resilience-building and social skills interventions to enhance body image satisfaction in this population.

Based on Shulman's (1986) concept of Pedagogical Content Knowledge (PCK), Technological Pedagogical Content Knowledge (TPACK) emerged and became a helpful framework for comprehending the objectives of using technology in pre-service teacher training programs. The purpose of the present study was to evaluate Iranian pre-service EFL teachers’ (PSEFLTs) perceptions towards their TPACK regarding their gender and academic year of study. To this aim, 254 Iranian PSEFLTs across various academic years of study filled out a 39-item EFL TPACK questionnaire developed by Baser et al. (2016). The questionnaire included seven categories: Content Knowledge (CK), Pedagogical Knowledge (PK), Technology Knowledge (TK), PCK, Technological Pedagogical Knowledge (TPK), Technological Content Knowledge (TCK), and Technological Pedagogical Content Knowledge (TPCK). Based on the collected data, which were subjected to the Kolmogorov-Smirnov test, descriptive statistics, t-tests, one-way ANOVA, and post-hoc analysis, it was found that PSEFLTs generally held mildly favorable perceptions towards their TPACK. Notably, the lowest mean score was observed for the TK component, while the component with the highest mean score was the CK component. In terms of the gender effect, statistically significant differences were found in the TK and TPCK dimensions, where males outscored females in both TK and TPCK and females outscored males in CK. Furthermore, an examination of the relationship between participants' TPACK and their academic years of study manifested a statistically significant difference primarily between freshmen and seniors. The results are expected to encourage curriculum planners to develop PSEFLTs’ training programs by integrating technology courses into the ELT curriculum.

Human beings employ different forms of linguistic politeness to ease communication and reduce the likelihood of conflict. With the rise of technology and social media platforms such as Email, Telegram, Twitter, WhatsApp, and Instagram, the concept of politeness has faced new challenges. The present study focused on Instagram comments and analyzed politeness strategies based on Leech’s grand strategy of politeness. The study examined a 20043-word corpus developed based on 696 posts across various topics on Instagram. The results revealed that Instagram users predominantly utilized negative politeness strategies (63.3%). Among the positive strategies, agreement constraints were the most frequently employed (32.7%), while tact constraint violations (32.1%) were the most common within negative strategies. The study utilized repeated measures of ANOVA and Tukey post hoc analysis via SPSS to examine differences among various constraints and their violations. Significant differences were found among most constraints, except for tact and modesty, generosity, and feeling reticence. In terms of constraint violations, no significant differences were observed between approbation and obligation of the speaker to others constraint violation, between agreement constraint violation and generosity constraint violation, between agreement and obligation of others to a speaker constraint violation, between agreement constraint violation and opinion reticence constraint violation, between sympathy and modesty constraint violation, between sympathy and feeling reticence constraint violation. The findings underscore the importance of analyzing language in specific media, providing insights into politeness and impoliteness in a specific medium. The results can enhance students' pragmatic skills and improve their online communication, prompting materials developers to consider such pragmatic dimensions.