The area of information retrieval (IR) has taken on increasing importance in recent years. This field is now interest to large communities several application domains (security, medicine, aeronautics, etc.). IR studies find relevant from the semi-unstructured type data. As resources generated after search can be extensive quantity and different quality, it essential rank these results according...

Abstract Preventive and curative intervention become an imperative to encounter the recent dilemmas of lakes its ecosystem, eutrophication, external contaminants load internal hydrological cycle disruption, drought or flood as a result global warning are some these which mainly caused anthropogenic activities. At present, mechanical chemical treatment approaches most popular applied techniques ...