in this paper the trade restrictiveness of agricultural policies in iran was measured by the triindex for the nine major agricultural products including wheat, rice, barely, maize, soybean,meat (beef meat), soybean oil, sugar and banana over the period 1981 to 2007. the main resultsindicate that there is no trend in above index and high volatility especially in 2006 and 2007years due to conside...

recently, much attention has been given to stochastic demand due to uncertainty in the real -world. in the literature, decision-making models and suppliers' selection do not often consider inventory management as part of shopping problems. on the other hand, the environmental sustainability of a supply chain depends on the shopping strategy of the supply chain members. the supplier selection pl...

The continued growth of world’s population and gradual increase of people’s living standards in developing countries have sped up the exhaustion of fossil fuels and caused large amount of greenhouse gas emissions. Although renewable energy sources (e.g. wind energy, solar energy, hydro energy and biomass energy) have developed rapidly in recent years, limitations existing in these energy source...

With the surge of the global energy demand, natural gas plays an increasingly important role in the global energy market. To meet the demand, optimization techniques have been widely used in the natural gas industry, and yielded a lot of promising results. In this chapter, we give a detailed discussion of optimization models in the natural gas industry with the focus on the natural gas producti...

The indicators used in economics to calculate the productivity scale are not always positive, therefore, existing models need to be developed to calculate the productivity scale for the semi-negative and semi-positive output index. However, companies with a lack of capacity need to achieve economies of scale and demand for realization simultaneously in the presence of a negative outflow index, ...

A growing global population, combined with factors such as changing socio-demographics, will place increased pressure on the world's resources to provide not only more but also different types of food. Increased demand for animal-based protein in particular is expected to have a negative environmental impact, generating greenhouse gas emissions, requiring more water and more land. Addressing th...

Background for the model: The model tries to determine optimal allocation of natural gas in the time horizon between 1 and 3 years by minimizing both • shortages of natural gas and • the direct costs of supplying natural gas. In order to obtain these goals, the time horizon is divided into smaller decision time periods whose durations depend on the following: • The uncertainty in future weather...

a r t i c l e i n f o Keywords: Malmquist–Luenberger index Urban water utilities Greenhouse gas emissions Nonparametric productivity measurement The energy use and greenhouse gas emissions in the provision of urban water and sewerage services have become an increasingly important issue in recent times. However, the impact of negative externalities such as greenhouse gas emissions on the product...