We present an algorithm that computes the structure of a finite abelian group G from a generating system M . The algorithm executes O(|M | √ |G|) group operations and stores O( √ |G|) group elements.

background: the most popular building materials are soil bricks and different types of stones. radon is released into ambient air from soil and stones due to ubiquitous uranium and radium in them, thus increasing the airborne radon concentration. the radioactivity in soils is related to radioactivity in the rocks from which the soil is formed. in the present investigation, the radon emanated fr...