A neoclassical growth model is examined with a special mound-shaped production function. Continuous time scales are assumed and a complete steady state and stability analysis is presented. Fixed delay is then assumed and it is shown how the asymptotic stability of the steady state is lost if the delay reaches a certain threshold, where Hopf bifurcation occurs. In the case of continuously distriubuted delays, we show that with small average delays stability is preserved, then lost at a threshold, then it is regained if the average delay becomes sufficiently large. The occurence of Hopf bifurcation is shown at both critical values.

Six water authorities share the Sefidrud watershed in the northwestern region of Iran and resolving the conflict among them is one of the major challenges of the water division of the government. In this paper a group decision support system will be developed for identifying the criteria and their weights, needed for ranking water resource projects in this watershed. This model will be based on extending the ordered weighted averaging (OWA) as an aggregation operator. The order weights of this operator will be determined first by using the minimal variability method. Second, a new measure will be developed to quantify consensus among the stakeholders. It guides the supervisor of the group decision making problem to negotiate with stakeholders effectively in the conflict resolution process. Using extended OWA, 13 water resources projects in the Sefidrud watershed will be ranked. A simulation study will also be reported, where the dependence of the optimal decision on the uncertainty level is examined. In a...