درخت حوزه‌های تخصصی

One of the most necessary operations in humanitarian logistics is the distribution of relief goods to the population in disaster areas. When a disaster occurs, some parts of the distribution infrastructure may be damaged and consequently make it impossible to reach all the demand nodes and delivering the relief goods. In this study, we focus on the planning of infrastructure recovery efforts in post-disaster response. The problem is the scheduling of the emergency repair of a network that has been damaged by a disaster. The objective is to maximize network accessibility for all demand nodes in order to deliver relief goods to them. We adopt a dynamic programming algorithm to solve the problem when more than one crew group is available. Our numerical analysis of the solution shows the performance of the algorithm. We, also, compare our results with some similar studies to indicate the differences between one and multi-crew scheduling.

This study investigates the role of religious tourism and experimental marketing in developing entrepreneurial sports opportunities in Mashhad. As the first step, the study's statistical population consisted of all tourists in Mashhad who have been there for at least one week for religious tourism and have also visited this city's recreational and sports centers. Moreover, three standard questionnaires were used to collect data and to analyze the data, the Skewness and Elongation tests were used to determine the data distribution, one-sample t-test to compare the mean of variables with the hypothetical standard, Kendall W test to prioritize the components from the sample view and modeling equations were used; on top of that, all analysis was performed using SPSS software version 23 and SmartPLS version 3. The results showed that the average score of religious tourism, experimental marketing, and entrepreneurial sports opportunities and their components are relatively good. Hence, their average score was more than three. Results also showed that religious tourism and empirical marketing positively and significantly affect developing entrepreneurial sports opportunities in Mashhad. Finally, the structural equation model of the relations of the three main variables of this research and their components had a suitable fitting.

The purpose of the present study is to present a model for the use of the Internet of Things in Iranian knowledge-based companies. From a purpose point of view, this research can be classified as applied research and in terms of data collection, it can be categorized as a qualitative and quantitative study. The main approach for achieving the model of using the Internet of Things is the grounded theory methodology which is based on a paradigmatic model. The research population for the qualitative phase is comprised of 25 executives and practitioners of knowledge-based companies who are somehow specialized in Internet of Things topics. The sample of this study was selected using the snowball sampling method and Cochran's formula for finite communities among all the managers and technology experts working in knowledge-based companies. After careful analysis of the interviews, 59 extracted concepts were identified in 5 main categories and 13 subcategories. Management requirements, customer requirements, and resistance economics give rise to the Internet of Things in knowledge-based companies.  The characteristics of the company, the characteristics of the human resources and the characteristics of the managers can provide a suitable ground for using the Internet of Things. And the conditions in the country, international pressures and international cooperation can be among the intermediary factors influencing the use of the Internet of Things. Raw materials and infrastructure can also be effective strategies for using the Internet of Things. Using the Internet of Things, customer-related factors, international collaborations, and expected results can be expected in knowledge-based companies.

Research on the psychological drivers affecting employees’ work engagement is insignificant and scare. Psychological capital and ethical work climate are two important of those drivers that their impact on work engagement haven’t been investigated yet. The aim of this study is to investigate psychological capital and ethical work climate effect on employees’ service behavior by the mediating role of employees’ work engagement. The statistical population of this study includes 7000 employees of National Iranian Oil Product Distribution Company. 394 employees were the minimum sample which their data were collected from 397 employees by questionnaires. Confirmatory factor analysis and structural equation modeling were used to data analysis. Results showed that psychological capital and ethical work climate have direct and significant effect on employees’ work engagement. Also results showed their effects on service behavior. Finally, work engagement effect on employees’ service behavior was confirmed. Managers by improving employees’ work engagement can have significant effect on employees’ service performance and employees by providing high quality services can quarantine customers satisfaction, benefit for stakeholders and business survive. Managers and business owners especially in service sector can improve work engagement through creating and developing ethical climate in business and through emphasizing on workers psychological derivers by education.