A common method for controlling a group of parallel converters in decentralized control strategy structure in an island microgrid, the use is the droop-down characteristics of frequency ω-P and voltage E-Q. However, the problem with using this method is that the reactive power is not properly distributed (in proportion to the capacity of the micronutrients) between the micronutrients, which may lead to overload in the converters. Microgrids may also suffer from dynamic stability problems such as power fluctuations, which can be increased by switching between active and reactive power control. To avoid this problem, the X / R ratio of transmission lines is an important parameter that should be carefully considered in the design of micronutrient controllers. By linearizing and simplifying conditions, the control system conversion function model becomes a single input-single output system, which is efficient enough to show the relationship between control parameters such as slope of droop characteristics and derivative sentences, virtual impedance, and voltage controllers. Using this model, stability conditions for different parameters are analyzed. Also, to improve power distribution stability, common droop strategies are modified by adjusting the slope as well as adding nonlinear sentence sections. This approach reduces the coupling between active and reactive power control and reduces the dependence of power distribution on grid parameters such as the X / R ratio. To evaluate the reliability of the proposed model, the simulation results in a sample island microgrid in MATLAB software are presented.

One of the issues of reliable performance in the power grid is the existence of electromechanical oscillations between interconnected generators. The number of generators participating in each electromechanical oscillation mode and the frequency oscillation depends on the structure and function of the power grid. In this paper, to improve the transient nature of the network and damping electromechanical fluctuations, a decentralized robust adaptive control method based on dynamic programming has been used to design a stabilizing power system and a complementary static var compensator (SVC) controller. By applying a single line to ground fault in the network, the robustness of the designed control systems is demonstrated. Also, the simulation results of the method used in this paper are compared with controllers whose parameters are adjusted using the PSO algorithm. The simulation results show the superiority of the decentralized robust adaptive control method based on dynamic programming for the stabilizing design of the power system and the complementary SVC controller. The performance of the control method is tested using the IEEE 16-machine, 68-bus, 5-area is verified with time domain simulation.

In recent years, Online Social Network (OSN) has been rapidly evolving and attracted many users. In OSN, users share sensitive information,therefore, effective access control models are needed to protect information from unauthorized users. Currently, Relational Based Access Control (ReBAC) is used to protect user’s private information. The authorization policy in ReBAC is based on the relationship type and depth among users,however, it is not sufficient to protect private information such as location, time, and age. In this paper, attributes are added to the social graph to establish an efficient access control in OSN, then a policy model is proposed for the new Attribute Relation Based Access Control model (A-ReBAC), and unambiguous Hybrid Logic (HL) policy language is used to formulate the access control policy model. To evaluate the proposed policy model two path-checking algorithms (depth-first search (DFS) and breadth-first search (BFS)) are applied to real datasets, and the time spent on access requests is calculated in the social graph of these datasets. The results showed DFS takes less time than BFS to do the task defined.

Background and Objective: Improvement in self-care and self-efficacy behaviors has proved to be a vital factor in a successful management of asthma. This study was carried out to determine the relationship of patients self-efficacy with control of asthma symptoms.Materials and Methods: This correlation study was carried out on 257 asthmatic patients (133 men and 124 women) aged 18-35, who referred to Sheykholrayis clinic of Tabriz, Iran, during 2011. Data collection tools included a questionnaire of social-personal specifications, asthma self-efficacy scale questionnaire and asthma control questionnaire as well as patients’ spirometer parameters. Data were analyzed using SPSS-17 and Pearson Correlation Coefficient test.Results: Among aspects of self efficacy, the regular use of medicine and patient relation with physician were demonstrated to be 4±0.6 and 2.7±0.7, respectively. Among aspects of asthma control, the level of activity restriction resulted by the disease during the past week and the number of spray puffs used during past week were 3±1.1 and 1.5±1.2, respectively. There was a significant relation between self-efficacy and asthma control (P<0.001, r=-0.378).Conclusion: This study showed that in asthmatic patients, self confidence is an effective factor in the control of asthmatic symptoms.

Objectives: Addiction, as a social phenomenon, is depended on several personal and collective factors and it is influenced by social system constraints. In normative system of societies, addiction is considered as a social harm or disease. Our main problem in this research is to analyze how people's commitment and social control in different aspects of social system can affect getting or not getting addicted. Besides, we will consider how we can explain their influence. In explaining this problem, two Theories have been used. First, Durkheim's Anomy theory which is based on independence of individual to social institutions and organizations such as family, school and etc. that caused behavioral deviations, in addition, the foundation of social behavior can be founded in social factors. Second, Social Control theory which found on individual who has potential to disobey the law moreover, modem society has provided opportunity for many illegal activities. Some criminal behaviors as using drugs and etc. has created entertainment that ended to immediate enjoyment.Method: The research method is Survey and our statistical population has been determined using random sampling method amongst addicts having been documented in the Office of Fighting against Narcotic drugs in a border city of Iran (Khaf, Khorasan's province). Data gathering has been done through assessing available documents in the mentioned office and using by questionnaires among 100 addicts and 100 Non-addicts (as the control group) and Performing validity and reliability tests for independent variables (logistic Regression and other tests).Finding: based on data gathering of this research, 62% of addictions are under low social commitment and just 5% of this indicator is estimated high. All of them have only used opium. The average duration of using opium has been 8/56 years. Rate of dependency on addicted group is considered 14% high, 49% average and 37% low. The average of social commitment and social control is 99% in significant level among addicts are lower than Non-addicts.Upon backward multiple logistic Regressions, using addiction estimate based on social commitment, the probability of addiction among people with low social commitment is high, considering 72% probability level. Also, the probability of addiction under the condition of low social control is high, considering 72% probability level. Statistics have implied that 83% of Non-addicts are under low social control.Result: Results from descriptive and explanatory findings imply that there is a meaningful relationship between social commitment and control and addiction phenomenon. The effect of social factors on addiction and expansion are determinate. The addicts are not separated from their environment and society. Social dependence and relationship make commitment. some dependence such as family, an institution and commitment to common activities like education, employment, states, saving, occupation in ordinary activity and belief to ethical codes social norms which are samples of commitments. In the result of this research, the appropriate solution for reducing addition has been reinforcement of socialization, collective conscientiousness and respect to social and ethical norms.

Worldwide epidemic had a specific role on human health and economic,Corona, for example, as a huge pandemic had an expand effect on human health, social relation, economic, politic and environment with severe respiratory disorder and high mortality rate in the world. Due to importance of SARS-Cov-2, the present paper deals with the route of transmission, their relation with sex, prevention and control. Research shows that sex-linked immunological differences as well as sex hormones are effective in responding to infectious diseases. Since COVID-19 is a critical global treat, therefore, in this article, factors such as restricting populations, appropriate medicine, forestry, population growth control, global ban on wildlife trade and nutrition, which are important factors in the spread of this organism are discussed. Results illustrated that sex hormones and presence of ACE2 receptors in male are the most important factors for developing the disease. Hence, it is recommended that they take more responsibility for the use of masks, regular hand washing with disinfectants, reducing the use of cigarettes and alcohol, and using foods containing vitamins such as A, C, E, zinc, Selenium and omega-3s and reduced presence in populations can prevent virus transmission.