درخت حوزه‌های تخصصی

We have a huge civic project, includes several sub-projects, which are divided into activities. This project is a project to rehabilitate 550,000 hectares of agricultural land in the provinces of Khuzestan and Ilam. The project has been divided according to the plots of land. The Jehad in Tehran is managing the projects. They need project scheduling as well as resource levelling and "lot-sizing". Levelling and lot sizing are the most important issues in utilizing the limited resources. For determining the scope and the size of those sub-projects as well as their parallel activities, so far, many models have been proposed. However, the models are weak either in higher resource utilization or in solving numerically the problems. In this paper, our effort has been concentrated on developing scheduling, resource levelling, and lot sizing model, based on balancing utilization of resources, so that the real size civil project could be solved within an acceptable duration time. This paper proposes a goal programming linear model for simultaneous project scheduling and resource levelling. This model determines the best schedule of sub-activities (optimal "lot size" of each sub-activity) to reach the minimum amount of diversion of resources consumed from the number of resources available for the entire periods of the planning horizon. In fact, if the best "lot sizes" have been taken, then minimum fluctuation of the active resources is reached. The proposed model has been used to schedule a project with 87 activities. This project has been scheduled and, accordingly, the optimal volume (the "lot size") of sub-activities have been determined for each activity at any period of time. In this way, only 4 resources out of a total of 32 resources are in shortage. In contrast, the scheduling of this project, using the CPM, results in a shortage of 13 resources.

This study aims to investigate the effect of advertising on expectations and perception of the brand with emphasis on the mediating role of customer experience management in the insurance industry. The present study is an applied research in terms of purpose. In terms of data collection method, it is a descriptive correlation and because the data were collected at a specific time, it is cross-sectional. Also, the main data for testing research hypotheses were collected in the field using a questionnaire. The statistical population of the present study consisted of customers of the insurance industry in Tehran. In order to determine the sample size, the principles of sample size in multivariate regression analysis were used to determine the sample size in structural equation modeling. The sample size was 385. The reliability and validity of the questionnaire were confirmed using face validity and reliability using confirmatory factor analysis, Cronbach's alpha coefficient and combined reliability. SPSS and LISREL software were used to analyze and test the research hypotheses. Findings from this study showed that advertising has a positive and significant effect on perception, brand expectation and customer experience management. Customer experience management also has a positive and significant effect on brand perception and expectation. Other findings of this study pointed to the positive and significant effect of the mediating role of customer experience management variable in the relationship between advertising and perception and expectations of the brand. Considering the findings of this study, advertising had the greatest effect on the customer experience. Also, the mediating effect of customer experience management variable in the relationship between advertising and brand perception was greater than the direct effect of advertising on brand perception.