One of the obvious reasons for most disorders in network service provisioning is network path congestion. Congestion avoidance in today's networks is too costly and sometimes impossible. With the introduction of SDN, centralizing the equipment's control plane has become possible. This paper presents an enhanced method named ESV-DBRA to avoid congestion in multi-tenant SDN networks. At first, ESV-DBRA monitors the traffic load and delay of all network paths for each tenant individually. Then, by merging the parameters obtained from the monitoring, the Service Level Agreements (SLA), and a novel proposed cost function, it calculates the cost of the network paths per tenant. As a result, traffic for each tenant is routed through the path/paths at the lowest possible cost from the tenant's perspective. Next, the bandwidth quotas will be calculated and assigned to the tenants over their optimal routes. Afterward, whenever congestion is likely to occur in a path, ESV-DBRA automatically changes the route or bandwidth of the tenants' traffic related to this path to avoid congestion. Related algorithms are also proposed.Eventually, simulations show that the proposed method effectively increases bandwidth utilization by 10.76%.

The purpose of this study is to assess the effect of Virtual social networks on social capital and happiness of the users in a social networking site. Using surveys, multistage cluster sampling, multiple regression and structural equation modeling, the following results have been obtained: Membership and participation in a Virtual social network affects the structural and functional aspects of social capital. These features have been observed in individuals who are members of the Network: Increased communication networks, membership in other groups, adherence to the norms and rules, trust in others and groups, obtaining in formation, support and the capability to get the resources. Development of social capital in Virtual networking sites increases feeling of the positive experience and decreases negative experience in users.To sum up, membership and participation in Virtual social networks, will increase social capital and consequently happiness.

Women entrepreneurs use Virtual social networks in their professional relationships. These relationships with higher quality leads to better performance in their businesses. The present study aimed to analyze the effects of Virtual social networks on improving rural women’s entrepreneurship. The statistical population of the study included all members of the Agricultural Development Specialized Holding Companies in Fars province in Iran. The study was conducted using survey and stratified random sampling methods with 269 individuals participated via questionnaires. The results indicated that Virtual social networks had a favorable effect on rural women’s businesses. There was a significant difference between women in the different studied counties regarding the effects of Virtual social networks on business. In addition, a significant difference was observed between women in various groups regarding the effect of Virtual social networks on business. In addition, greater effect of Virtual social networks on women’s businesses led to higher business resilience among the women entrepreneur and their businesses, which resulted in increasing the women’s information about business activities and their entrepreneurial activities in their businesses. Further, more use of social networks by the women led to more use of marketing methods and strategies. Therefore, it is suggested that Agricultural Development Specialized Holding Companies use the functions of Virtual social networks in order to information transfer, networking and online training for members when necessary. Also provide the necessary training in the application of appropriate marketing methods and strategies to rural women entrepreneurs using these networks.

Future broadband networks will be dealing with communities of users with vast differences in their traffic management, access, security, and quality of service requirements. Differentiated treatment of various communities of users results in several logical overlay subnetworks on top of a common physical infrastructure. This paper deals with configuration and  dimensioning of these subnetworks on a dynamical basis in order to adapt the resource allocation of the VNs based on their traffic profile and service quality requirements. The objective is to maximize resource efficiency and .hence network revenue for a given available physical resources. The parameters to be optimized are capacity allocations of logical links and traffic distribution factors that indicate how the total traffic between an end-node pair is distributed through available parallel routes. A general scaleable algorithm is proposed which is capable of dealing with complex constraints and traffic models. The resulting adaptive Virtual network framework provides an efficient mechanism for supporting quality of service (QoS) in a high-speed multi-service environment as well as quick deployment of Virtual private networks (VPNs). Although the initial focus of this work has been on ATM networks, due to the generic nature of the underlying subjects (e.g. resource allocation, differentiated service, etc.), it can also be a basis for QoS support in JP networks.  

Technologies and various media have affected social institutions such as family and cause shape changes in relationships within the family. One of the means of communication that are easily and widely used in the household is Internet. With the entrance of media, especially the Internet to the family, changes in personal, social, public and private relationships are occurred. The use of social networks gets more and more popular day by day and it can be said that information technology has become an integral part of life. As social networks in diminish face-to-face relationship which can be especially seen in the relations between spouses. This study aims to evaluate the impact of social networks on the couple's commitment with descriptive and analytical method. Because the sample in this study is in synchrony with the population, a sample of married couples working at the Red Cross, Social Security Organization and medical universities are selected by convenient sampling technique. Questionnaires are provided after their approval, the sample size is 300 persons. Results show that there is no significant difference in using social networks between genders. There is an indirect significant relationship between using social networks couples’ trust. There is an indirect significant relationship between using social networks couples’ commitment. There is a direct significant relationship between using social networks couples’ dependence. Finally it can be said that despite the positive results of using social networks, they also have negative consequences such as a kind of alienation called living alienation which is emerging. In other words self-alienated and alien self are occurring.

Objectives: The purpose of the present study is to investigate the motivational factors in face book users and approximate number of users, approximate number of friends and friends of the opposite sex. Method: The method of the research is descriptive survey and has been done among semnan university students in academic year of 1390-91 among whom 460 persons have been selected at first section and 300 persons at second section at twenty classrooms. The participants are selected according to multiple stages clustering sampling method. The tools of the study is questionnaire of motivations for using face book (golnar, balsi and kakayer, 2010). Results: The results of the present study showed that the most important reason for inclination of users toward using face book is narcissism and self-expression (72.56 percent). The second motive to use this site is the personal status with agreement of 65.5 percent. The third motivation is media drenching and performance because of which 68.41 percent of people are the users of the site. The forth motivation is information seeking with 53.54 percent. The fifth motive is pastime with 52.46 percent. The sixth one is relationship maintenance in touch with 37.8 percent, and the seventh motive is entertainment with agreement of 35.35 percent. All the descriptive results indicate that boys and girls differ from each other in amount of using face book with different motivations. Moreover, about two-thirds of students in the Virtual social networks are fixed; each having about 10 friends or contacts and almost 4 of them from the opposite sex. Conclusion: The authors of the survey conclude boys and girls are different in using face book with various incentives. The results of the present paper can be useful in analyzing the needs of youth and their circumstances.

Virtual networks are the most important tools of soft war and that is very useful in future wars. The purpose of this research, is recognition its functions, opportunities and threats. The results of research show that exigency strategies in necessary for encounter these threats, and it must be one of the strategic priorities of our country. In this research, we interview with defensive managers in strategic and cyber space domains, scholars and experts.The result of this research show that exigency strategies such as formation of Virtual network’s war room, training elites of cyber space, acculturating and educating public people in these domains, should be at topic of priorities country’s strategies in front of Virtual network in the future war.

this paper examines the mechanism that influences the behavior of citizen participation through the use of mass media. The research method is descriptive-analytic correlation type. In terms of controlling the status of the research, a survey is a cross-sectional (second half of 1396). The statistical population of the study was citizens aged 18 years and above the multi-city areas of Sanandaj. The size of the sample was determined according to the maximum dispersion and error rate of 5% based on the Cochran formula. 384 persons were selected and the sampling was done by multi-stage cluster sampling. The descriptive results of the study indicate that the respondents in the cyberspace have a high presence and high rank of respondents in the audiences' behavior and, to some extent, in moderate behaviors (such as voting, launching a political debate, trying to persuade another to vote in a particular way, etc. ) Mediocre behaviors (such as attending a political gathering, financial support for a political or nominee, contact with political officials, etc. ). Also, the results indicate a significant and direct relationship between online social capital and political participation in the three dimensions, especially its moderate (0. 564). In addition, the results of the study indicated that the rational choice variable (reducing the cost of participation, time, and increasing opportunities) was a mediating variable in the interface between presence in cyberspace and political participation, and the sum of these two variables was about 45% of the variation of variables Political participation has been explained.

The main purpose of this study is to investigate the role and place of Virtual networks in the formation of modern identity of young people. This research was conducted with mixed method, qualitative (GT) and quantitative (survey) and in terms of practical purpose and in terms of the method and nature of the research, it is descriptive and survey type. The method of data collection was a researcher-made questionnaire, and the data collection tool was the answers received from the statistical population. To measure reliability in this research, Cronbach's alpha coefficient, which is extracted through SPSS software calculations, was used. Also, to calculate the validity of the questionnaire, it was revised and finalized through content validity and using the opinions of professors.In order to achieve Strauss and Corbin's paradigmatic model, with foundational data method and interviews with 13 experts, the findings were coded in three open, central and selective stages, and the result of coding to achieve the paradigmatic model included: causal, contextual, intervening factors, strategies and consequences. . In the second step, the required data was obtained using the foundation data method and using a researcher-made questionnaire, by surveying 384 young Tehrani users from 5 regions