hossein rahmati

The success of organizations in a complex and changing environment requires knowledge-based competitive advantage. Research has shown that the benefits based on the internal capabilities of the organization more effectively determine the competitive position. By encouraging creativity and innovation and building trust among employees, Knowledge-oriented leaders create appropriate organizational culture to share knowledge in order to adapt rapidly to environmental change and to achieve organizational goals. The present study seeks to test the moderating role of knowledge-intensive culture in the relationship between knowledge-oriented leadership and knowledge sharing. Managers of knowledge-based companies established into Shahid Beheshti University and University of Tehran, answered the relevant questionnaire. After the statistical analysis of the data which were done using structural equation modeling (SEM), the findings of the study showed that knowledge-oriented leadership style did not affect knowledge sharing in the study population, while knowledge-intensive culture moderated the relationship between knowledge-oriented leadership and knowledge sharing. It should be noted that this article has theoretical and practical implications for researchers and executives.

The challenge faced by organizations is the transformation of social values, as well as other elements of marketing environment over time, which makes corporate social responsibility more important than the past, so in order to ensure success, the marketers function and the products and services provided by the company along with observing environmental and community-related issues.Therefore, in this study, the effect of social responsibility and environmental orientation on marketing performance with regard to the mediating role of green marketing orientation in Zar Makaron Company is investigated. This research is an applied research in terms of purpose and in terms of data collection, a descriptive survey is a survey. The statistical sample included 120 managers and experts of Zar Makaron Company. To collect data, a standard questionnaire was used. To analyze the data, structural equation test were used by AMOS software. The results of data analysis indicate that social responsibility have a significant and positive effect on marketing performance through the tactical, strategic and internal green marketing orientation. environmental orientation have a significant and positive effect on marketing performance through the orientation of green marketing

In today's society and with regard to its social construction, the category of psychological and social security is very important and many of the problems and frustrations that threaten our society today are rooted in such cases as the use of virtual social networks and their impact on society. Therefore, the purpose of this study was to examine the effect of using virtual social networks on social security of students residing in Jahrom city. In terms of its objectives this study is of an applied research and in terms of methodology it is a descriptive-survey study. The research population comprised of students living in Jahrom, and the sample size was calculated using the Cochran formula as 375 individuals. A researcher-made questionnaire was employed for data collection. For descriptive analysis of data SPSS software was employed. To test the hypotheses, the structural equation modeling and LISREL software were employed.  Since the value of t-value in all of these relationships is greater than 1.96, it can be said that the use of virtual social networks affects students' social security and has the highest impact on decreasing ethical principles (0.58%). The use of virtual social networks on social security of students and its components (creating an inappropriate process of socializing, breaking the foundation of the families, decreasing ethical principles, social isolation and physical harms) have a positive effect and there is a significant relationship among them. Therefore, it can be concluded that the research hypotheses were confirmed.

A review over the rainfall-runoff studies shows that, humid regions have received worth more attention than arid and semi-arid regions. So that, in this study, the rainfall-runoff process of an arid and semi-arid district, namely; Bar Arye Watershed with an area of about 112km2 and a mean annual precipitation of 307mm was simulated by using the spatially distributed rainfall-runoff model, WetSpa which has the ability to be connected to the geographical information systems. The period from 2003 to 2008 was applied for modeling. In the present study, according to Nash-Sutcliff criteria with the value of 0.69% for the validation phases it was indicated that the model has shown a good performance in modeling the rainfall-runoff. The rainfall-runoff coefficients of the observed and simulated values were equal to 0.59 and 0.57, respectively. This shows that the model has a good performance in estimating the values of runoff.