rivers and runoff have always been of interest to human beings. in order to make use of the proper water resources, human societies, industrial and agricultural centers, etc. have usually been established near rivers. as the time goes on, these societies developed, and therefore water resources were extracted more and more. consequently, conditions of water quality of the rivers experienced rap...

Companies  with  sustainable  development and competitive advantage goal,  need to consider  suppliers as a part of their own core competencies. Accordingly, supplier selection should be considered as an important part of the strategic decisions of these kinds of companies. Supplier selection is usually formulated as a multi criteria decision making problem.  When suppliers were selected, it is...

in this thesis, we consider a mathematical model of cancer with completely unknown parameters. we study the stability of critical points which are biologically admissible. then we consider a control on the system and introduce situations at which solutions are attracted to critical points and so the cancer disease has auto healing. the lyapunov stability method is used for estimating the un...