محمد همتی

INTRODUCTION: Since Iran is located in the semi-arid belt, it has faced such issues as drought, dust crisis, and intensified migration. The assessment of the effects of climate change includes identifying some key aspects of uncertainties used to estimate its impacts, such as uncertainties in the context of Atmosphere-Ocean General Circulation Models (AOGCMs): in regional-scale climatology, in statistical or dynamic downscaling methods, and parametric and structural uncertainties in different models. One of the most important sources of uncertainty in climate change is the use of different AOGCMs that produce different outputs for climate variables. METHODS: In this study, to investigate the uncertainty of AOGCM models, the downscaled data of the NASA Earth Exchange Global Daily Downscaled Projections dataset obtained from 21 AOGCMs with medium Representative Concentration Pathway4.5 scenario were downloaded from the NASA site for 81 cells in Hamadan Province, Iran. After the validation of the models, they were evaluated against the criteria of the coefficient of determination and model efficiency coefficient in comparison with the data of the Hamedan synoptic station in the statistical period of 1976-2005. To reduce the uncertainty of AOGCMs, the ensemble performance (EP) of models was used in Climate Data Operators software. FINDINGS: It was revealed that MRI-CGCM3, MPI-ESM-LR, BNU-ESM, ACCESS1-0, MIROC-ESM, MIROC-ESM-CHEM, and MPI-ESM-MR models had better performance than similar models. It was also found that IPSL-CM5A-LR, CNRM-CM5, CSIRO-Mk3-6-0, CESM1-BGC, and GFDL-ESM2M had the lowest correlation between observational and simulation data of mean monthly precipitation. CONCLUSION: According to the results, this method could provide a good estimate in the base period (1976-2005), compared to the data of the Hamedan synoptic station, and was more accurate compared to the single implementation method of each AOGCM model. The results of EP of models in the future period (2020-2049) showed that precipitation will not change considerably in the future and will increase by 0.23 mm. In addition, the average, maximum, and minimum annual temperatures will increase by 1.54°C, 1.7°C, and 1.40°C, respectively.

Competitive advantages play a unique role in organizations' successes or failures because of customers' very speedy accessibility to suppliers and manufacturers. Indeed, this is competitive advantages which can make firms and organizations survive and grow in today's increasing competitive field attaining by creating and or improving their capabilities. The main goal of the study is to design a grounded theory model extracted from the transnational capabilities, but this required to explore the transnational capabilities aiming for the international markets entry. The statistical population of this qualitative research included experts and managers working in the steel pipe manufacturing companies of Iranian gas and oil industry. The data collected via interviews. The validity assured by counseling with the elites and university professors and the reliability verified by the Delphi technique. The findings revealed 496 open, 44 axial and 9 selective codes including: 1) Marketing, 2) Managerial, 3) Human Resources, 4) Financial, 5) Manufacturing, 6) Quality & Standards, 7) Research & Development 8) Logistics and 9) Interactions and counseling with the government. Finally, a new model extracted and represented from analysis of the axial coding process of the grounded theory. The model precisely clarified relationships among the components including casual conditions, context, actions/interactions (strategies), intervening conditions and consequences. Recognition of the relationships of the components will help better understanding of the capabilities. This will lead to attain the competitive advantages needed for successful entry into the international markets.