Aims: To provide a brief overview of literature studying the relationship between mathematical competences in childhood and adult life success measured in academic achievements, socioeconomic status, and health measures. Results: Mathematical competences are determined by the ability to process mathematical symbols and quantity determination which is partially inborn. We can stimulate mathemati...

the scarcity of water resources and supply resources limitation, have caused an increasing gap between water supply and demand specially in recent decades in almost all regions of the globe. one of the best known solutions proposed by the economists is using the different water pricing approaches thereby obtaining the optimal allocation and social justice. to this purpose, this paper uses the p...

Positive linear systems are frequently used as mathematical models in research areas like biology and economics. The problem to classify all minimal realizations of these systems is treated in this paper. Extensive use is made of the theory of polyhedral cones. Suucient and necessary conditions for the existence of a positive realization are given, but the problem of minimality leads to the fac...

in this study economic and welfare impacts of establishing irrigation water market in qazvin province as well as potentiality of irrigation water transfer under stress irrigation conditions in the cities of qazvin province were analyzed. to achieve the above objectives, positive mathematical programming model and state wide agricultural production functions were used. to achieve applicable resu...

this paper develops positive mathematical programming (pmp) model to determine the optimum cropping pattern and water demand function in six regions of lower part lands of shirindarre dam in north khorasan province of iran and then estimates the expected pay for water in each region. the quantity of water supplied from such different water resources as dams, wells, and rivers in different scena...