The yellow pages service of GTE SuperPages enables Web users to flexibly search through liitings of 11 million businesses in over 17000 categories. To achieve the flexibility desired it uses an Information Retrieval (IR) engine to search through complex listing objects. The objects themselves are stored in an object database. The use of the IR engine enables us to create an index that spans all...

Animal behavior is often altruistic. In the frame of the theory of natural selection, altruism can only exist under specific conditions like kin selection or reciprocal cooperation. We show that reciprocal cooperation, which is generally invoked to explain non-kin altruism, requires very restrictive conditions to be stable. Some of these conditions are not met in many cases of altruism observed...

although on the basis of geo-economic theories, study of energy-related issues is of strategic importance to all countries, energy resources are no more restricted to oil and gas reserves as was the case during the past century. of course, these resources are still key elements of global energy reserves. today, in addition to geo-politics and geo-economics, the concept of hydro-geopolitics puts...

The purpose of the present study was the simulation of climate change effects on groundwater resources in Iran by using the dynamic systems approach. The approach was performed through system dynamics modeling process including problem explanation, system description, model development, model testing, and the use of the model for policy analysis. The impact of the application of various exogeno...

non-renewable natural resources play an important role in sustainable development of developing countries such as iran. however, if natural resources are to be preserved for future generations, proper use of such resources will be imperative. women are one of the prime users of natural resources. this study assesses the conservational behavior of rural women and factors influencing such behavio...