فهرست مطالب sadegh ranjbar

Self-control refers to the self-initiated ability to regulate one’s thoughts, emotions, and actions. It plays a crucial role in predicting real-life outcomes. Existing literature highlights self-control as an essential skill that can help individuals achieve their goals and enhance various aspects of their lives.

The present study aimed to determine the impact of three different sports—middle-distance running, chess, and kata—on the self-control of adolescents.

Methods and Materials:

The study employed a quasi-experimental method with a pretest-posttest control group design. The statistical population consisted of male adolescents aged 13 to 18 in Kermanshah. 48 participants were selected by a purposive sampling method. Subsequently, the sample members were randomly assigned to three intervention groups (middle-distance running, kata, and chess), along with a control group. Before the intervention, a pre-test was conducted. The experimental groups followed specific protocols for each sport over a two-month period, with training sessions held three times a week, each lasting one hour. Post-tests were administered at the end of the intervention, and a follow-up assessment occurred after two weeks. Tthe Tangney, Baumeister, and Boone Self-Control Scale (2004) and a demographic consent form were the research tools.

The study findings indicated significant differences in self-control scores across pre, post, and follow-up time intervals (Wilks’ lambda = 0.311, F(2,43) = 47.65, p < 0.00123). Additionally, there were significant differences in mean self-control scoresamong the four groups (middle-distance running, chess, kata, and control) (Wilks’ lambda = 0.199, F(9,102.37) = 10.70, p < 0.00000148).Specifically, middle-distance running demonstrated a significant improvement in self-control among adolescents compared to chess and kata (p ≤ 0.05).

Incorporating sports with specific demands, especially middle-distance running, can be an effective intervention for enhancing self-control among adolescents. Engaging in middle-distance running positively impacts self-control, offering young individualsan avenue to develop this essential skill.

Sports performance is an important issue in sports that researches have always sought to identify different methods to improve it. One of the methods that has received special attention in recent years is tDCS (transcranial direct current stimulation) and its effectiveness in improving sports performance. tDCS changes the activity of brain areas involved in sports performance by stimulating and inhibiting nerve cells and neural plasticity. Researches have used this method in improving sports performance and have been associated with different results. The present study was conducted with the aim of reviewing the studies conducted in this field. The research method was descriptive and review. In order to collect data, keywords tDCS-sport, sport performance, sport-neuron plasticity, tDCS-neurodoping were searched from Google.scholar, apa.org (Psychinfo) and Elsevier research websites. Then the abstract, results and findings of each article were examined. 16 articles were selected and their results were analyzed. The results of the research showed that the use and effectiveness of tDCS in improving sports performance has a positive role and is associated with improving the performance of not only ordinary people but also athletes. However, the results of review studies and meta-analyses show that heterogeneity in the type of sports activity, sample size, research design, stimulation areas, tDCS protocols and methodological limitations reduce the effect size of improving athletes' performance with tDCS. Therefore, it is necessary to conduct studies focusing on specific neural sites and specific sports functions of each discipline. In general, from these findings, it can be concluded that tDCS is a safe method without side effects and has a positive effect in improving sports performance of athletes, which requires more research.

The attempts made by Saudi Arabia to utilize the soft power of sports over the last decade have helped it envision a promising post-oil future. This study aims to explain the paradigm governing the expansion of sports interactions between Iran and Saudi Arabia.

The statistical population consisted of 11 political science and sports science professionals with written work (e.g., papers, books, notes, or interviews) on public diplomacy, sports diplomacy, and diplomatic interactions in the Middle East, especially between Iran and Saudi Arabia. Sampling was performed through purposive (snowball) sampling and the Delphi method until theoretical saturation. The validity and reliability of this research were evaluated with the contribution of interviewees with Intra-subject agreement of two coders.

The research findings indicated that four indirect categories (i.e., geopolitical, ideological, economic, and sociocultural categories) and three direct categories (i.e., sports events, human capital, and sports economy) constituted the paradigm governing the diplomatic interactions between Iran and Saudi Arabia. The key components of indirect and direct categories were economic concepts with a mean of 4.17 and sports economy with a mean of 4.30, respectively.

According to the research findings, since Saudi Arabia has put substantial effort into organizing sports events and paid special attention to this area over the last decade, sports can be considered an intriguing means for these two countries to expand their political and economic convergence in the future.

Religious and political challenges with Saudi Arabia in the last decade, followed by the burning of the Saudi embassy in Tehran, invited the sport of the Islamic Republic of Iran, especially national an club’s football, to a new problem. The purpose of this study was to analyze the anti-diplomacy of Iranian football as a geopolitical challenge against Saudi Arabia. The present study was a qualitative (descriptive-analytical) type of library studies in terms of applied purpose and in terms of data collection; The statistical population was equal to 54 works of international sports relations and in particular sports diplomacy in the Middle East region and the statistical sample was equal to the contents about Iranian football anti-diplomacy, soft power of Iran and Saudi Arabia. The findings of the present study showed that the national teams of Saudi Arabia and Iran, as the main players in the Arab world and the Middle East, respectively, have played a significant role in the development of football in this region and many Asian football achievements, including being on the championship platform in the Asian Champions League. And attending the FIFA World Cup has been the result of the two countries' attention to football as their most popular sport; Finally, football in the confrontation between Iran and Saudi Arabia in the Middle East can be a tool for convergence and as one of the basic geopolitical codes of the two countries, which with its soft nature can open a diplomatic path in re-examining the relations between the two countries.

 In sport context learning a skill, and performing it flawlessly is of great importance. There is a unanimous consensus among sport scientists, coaches, and athletes, that along with physical, technical and tactical skills, psychological skills are also necessary for an optimal sport performance.

 The aim of the present study was to investigate the role of mental toughness in motor learning and sport performance in wrestling.

 This study was semi-experimental and its population were physical education students of the University of Tehran in 2018. Using intensive sampling method, 28 student-athletes, who never had any past wrestling skill practices, were selected. Subsequently, using Mental Toughness-48 questionnaires, they were divided into two equal groups of high and low in mental toughness. After that, all participants were randomly assigned into two groups of equal size and 30 wrestling skills were taught to them twice a week for 3 months by two professional wrestling coaches. Their motor learning was assessed by three other professional coaches in the last week of training and one week after the last session. Motor learning score was obtained by calculating the mean scores of acquisition and retention stages. Then, two groups with high and low levels of mental toughness were compared regarding their motor learning scores. Tools used in this study included demographic consent form, wrestling skills test and The Mental Toughness Questionnaire-48 (MTQ 48).

 The results suggested that mentally tough student-athletes demonstrated significantly higher motor learning scores compared with their counterparts who had lower levels of mental toughness (P ≤ 0/05). This advantage was persistent both in the acquisition and retention stages (P ≤ 0/05).

 It was concluded that mental toughness could be considered as a key factor in motor learning. Therefore, it is recommended to coaches and athletes to develop mental toughness in order to enhance motor learning and achieve successful performance.

Efficient management of energy resources is very important in smart buildings. In this work, model predictive control (MPC) is used to minimize the economic costs of buyers equipped with generation units, energy storage systems and electric vehicles. For this purpose, predictive control manages available energy resources by exploiting future information on energy prices, absorption and generation power profiles, and electric vehicle (EV) usage, such as departure and arrival times and predicted energy consumption. EV Batteries In particular, unlike the heuristic method, the MPC approach has been proven to be able to efficiently manage the available energy resources to ensure full recharging of the EV battery overnight.
Aiming at optimal performance in terms of economic cost minimization in time-varying price scenarios, reducing rms current stresses and recharging capability of EV batteries. Moreover, the proposed control is shown to be able to limit the maximum power absorption from the grid within the defined limits, which is a valuable feature in scenarios with widespread adoption of EVs in order to limit the stress on the electrical system. and the ability to recharge EV batteries. In particular, unlike the heuristic method, the MPC approach is proven to be able to efficiently manage the available energy resources to ensure full recharging of the EV battery overnight while always meeting all system constraints. Moreover, the proposed control is shown to be able to limit the maximum power absorption from the grid within the defined limits, which is a valuable feature in scenarios with widespread adoption of EVs in order to limit the stress on the electrical system. In addition, the proposed control is shown to be able to limit the maximum power absorption from the grid within the defined limits .

In sport context learning a skill, and performing it flawlessly is of great importance. There is a unanimous consensus among sport scientists, coaches, and athletes, that along with physical, technical and tactical skills, psychological skills are also necessary for an optimal sport performance.

The aim of the present study was to investigate the role of mental toughness in motor learning and sport performance in wrestling.

This study was semi-experimental and its population were physical education students of the University of Tehran in 2018. Using intensive sampling method, 28 student-athletes, who never had any past wrestling skill practices, were selected. Subsequently, using Mental Toughness-48 questionnaires, they were divided into two equal groups of high and low in mental toughness. After that, all participants were randomly assigned into two groups of equal size and 30 wrestling skills were taught to them twice a week for 3 months by two professional wrestling coaches. Their motor learning was assessed by three other professional coaches in the last week of training and one week after the last session. Motor learning score was obtained by calculating the mean scores of acquisition and retention stages. Then, two groups with high and low levels of mental toughness were compared regarding their motor learning scores. Tools used in this study included demographic consent form, wrestling skills test and The Mental Toughness Questionnaire-48 (MTQ 48).

The results suggested that mentally tough student-athletes demonstrated significantly higher motor learning scores compared with their counterparts who had lower levels of mental toughness (P ≤ 0/05). This advantage was persistent both in the acquisition and retention stages (P ≤ 0/05).

It was concluded that mental toughness could be considered as a key factor in motor learning. Therefore, it is recommended to coaches and athletes to develop mental toughness in order to enhance motor learning and achieve successful performance.

Nowadays, damage models are used to simulate and predict the failure occurrence regions in manufacturing processes. One of the most famous models that is widely used in finite element commercial codes is Johnson-Cook damage model. The aim of the present research is to determine the constants of Johnson-Cook damage model for pure commercial copper sheet. For this, three different tensile testing specimens (a smooth (standard) specimen and two notched specimen with different notch radii of 10 and 2 mm) were separated along with the rolling direction and tensile tests were conducted on them. The stress triaxiality was determined for each of the specimens, by using the Bridgeman equation. Next, regards to the dependency of the fracture strain to the stress triaxiality, the constants of Johnson-Cook damage model was determined. Numerical simulation was used to evaluate the satisfaction of the method used to determine the constants of Johnson-cook damage model. For this, the error in fracture strain was used as the criterion and the value of it was calculated for each of the tensile testing specimens. The average value of error in fracture strain for three tested specimens was obtained as of 9.68 percent that showed the satisfaction of the method used in this research to determine the constants of Johnson-Cook damage model. The results of this study can be used to simulate the manufacturing processes of the studied copper sheet.

It has been invented a many techniques to enhancement of sport performance nowadays which used by athletes in different fields. Between these techniques, neurofeedback, as a noninvasive brain method, has paid much attention to itself. Many studies have investigated the effectiveness of neurofeedback training on sport performance enhancement that finds different results. The present study has done to report investigated researches by accessible sampling in athlete’s discrete skills. First, English articles have been searched by keywords like “neurofeedback” and “EEG Neurofedback” and “sport performance”, athletic performance”, “shooting performance”, “archery”, “putting performance” and “Golf”. The articles have been gathered in PsycINFO, PubMed, Web of science, EBSCO and Google Scholar. Meta-analysis and review articles added too. Time perid of articles was 1990 to 2020. Persian articles with same keywords in SID, Noormags, Magiran and Irandoc were searched. Time period was 2001 to 2020. By related keywords, a number of 16 studies have been chosen in related to the criteria of the research. Then the results of any research extracted by any of authors and reported in findings. Results showed that different recruited neurofeedback protocols in any study can effect on the results of the studies and it is necessary to pay attention in athletes. Based on the findings of the study it can be concluded that neurofeedback training has positive effects on sport performance enhancement.

The aim of the present study was investigate the role of mental toughness on learning of Wrestling skills in young athlete. This study was semi-experimental and its population were physical education students of Tehran University in 1395. A total of 30 student-athletes under 23 years old, those who not familiar with wrestling skills randomly assigned into two groups and they learned thirty-skills training within three months by two wrestling coaches. At the end of the last session and one week after the last session acquisition and retention test was performed. According to the mean scores of learning, athletes divided in two excellent and weak performance groups . Tools used in this study included demographic consent form, a questionnaire for wrestling skills and 48 questions version of the mental toughness questionnaire. normal distribution of data into two groups was examined, then the t-test results showed that the mental toughness difference between excellent and weak performance groups was statistically significant. considering that all subjects had acceptable levels of physical fitness, According to The results of this study probably mental toughness could be a key factor in learning wrestling skills. Therefore, it is recommended for coaches and athletes to develop mental toughness to achieve success in their sport.

According to numerous studies in sport psychology, it is proved that optimal athletic performance relates to many psychological factors and behavioral characteristics influence on athletic development. This paper is aimed to compare mindfulness, emotional intelligence and mental toughness in successful and unsuccessful karate athletes in Iranian men’s karate super league. This research is a kind of casual-comparative research and the research population consists of Iranian men’s karate super league in Kumite section in 1394. Also, primary data is provided by the available method from 70 karate men, including two teams from high ranked and three teams in lower ranked position. Then, using information from competitions and results for each athlete, the optimal performance of karate men is calculated and two successful and unsuccessful groups are determined (each group includes 30 athletes). The research material in this work includes the demographic questionnaire, the sport mindfulness scale, the Self-Report EI Test and the mental toughness quesioneri_48. After normalization of data using the K-S and Shapiro-Wilk tests, an independent T test results show that the emotional intelligence and mental toughness between successful and unsuccessful athletes were significant difference. However, there was no significant difference between mindfulness. Finally, the results indicate that the psychological characteristics have an effect on the success and the performance of the two different groups which are in the highest ranked of Asia and world karate.

Nowadays, numerous studies have shown that optimal athletic performance is related to many psychological factors. This paper aimed at comparing motivation and perfectionism of successful and unsuccessful karate athletes in Iran men’s karate super league. This study was casual-comparative and the population consisted of karate athletes of Iran men’s karate super league in 2015 in Kumite section. Primary data were collected by convenience sampling method from 70 athletes of all participating teams (especially two high ranking teams and three low-ranking teams) in karate super league. After collecting the data of the number of competitions and their results for each athlete, the optimal performance of karate athletes was calculated and two successful and unsuccessful groups were determined (each group 30 subjects). The demographic questionnaire, the sport motivation scale, and the sport perfectionism scale were used in this study. The K-S and Shapiro-Wilk tests were used to investigate the natural distribution of data. The results of independent t test showed a statistically significant difference in adaptive perfectionism (positive) between successful and unsuccessful athletes. However, there was no significant difference in maladaptive perfectionism (negative) between the two groups. Furthermore, the Mann-Whitney U test results showed that the difference in all motivation subscales was not significant between successful and unsuccessful karate athletes. Finally, it can be stated that some findings emphasize the role of psychological characteristics in sport success and performance in the two groups which have in the highest rank of Asian and world karate.