Social foraging differs from individual foraging because it alters both resource availability and the forager's behavior. We examined responses of starlings to the presence of conspecifics by manipulating foraging-group density experimentally, while ensuring that each subject's foraging...

Group foraging allows for individuals to exploit the food discoveries of other group members. If searching for food and searching for exploitation opportunities within a group are mutually exclusive alternatives, the decision to use one or the other is modeled as a producer-scrounger game...

The land-use structure and ecological service functions of the Erhai Lake Watershed are being altered by rapid socioeconomic development and urbanization, which will ultimately lead to the generation and aggravation of agricultural and urban non-point source pollution over the entire region....

Although the key issue in the WTO negotiations on agriculture is subsidies reduction, the EU and USA still account more than 85% of the world agriculture subsidies. An important policy question confronting developing countries is whether the reduction agreed within the Hong Kong conference could...

Constructing a robust hydraulic network model is vitally important, but a time-consuming task. Over last two decades, several approaches using optimization techniques have been developed for identifying model parameters. Although most of the methods can make the model agree with field...

A computer simulation model is presented for the analysis of a solar photovoltaic/thermal (PV/T) hybrid collector with air as heat transfer fluid and algorithm for making quantitative prediction regarding the performance of the system is described. Thermal efficiency curves for the solar PV/T...

The technological advances have been accompanied by an enormous demand for energy. Non-renewable energy sources have supplied this energy so far, but it has also led to an erosion of the worldwide environment. The US/Mexico border region has some unique advantages and/or opportunities. The...

A solar tunnel drier is optimised for drying of chilli in Bangladesh. The simulation model was combined with the economic model of the solar tunnel drier and adaptive pattern search was used to find the optimum dimensions of the collector and the drying unit. Two optimum designs are obtained....

This paper explores the inherent delays of airline schedules resulting from limited buffer times and stochastic disruptions in airline operations. The reliability of airline schedules is discussed and a set of measuring indices is developed to evaluate schedule reliability. It is found that...