Geochemical background is the basis of anomaly evaluation in mineral exploration and environmental investigation. However, value obtained from secondary media inevitably affected by weathering, transportation, sorting, which leads to depletion or enrichment chemical elements. This problem can be avoided geochemical mapping exposed crust. In this paper, more than 38,000 samples rocks data were c...

The Qiongdongnan Basin is an important gas hydrate exploration area in the South China Sea, but accumulation process poorly understood. By selecting Lingshui (LS) target and using first-hand geochemical data, three-dimensional seismic independent thermal insulation pressure maintaining shipborne core analysis system, this study, comprehensive geological evaluation was carefully conducted around...

a well-known algorithm of clustering is k-means by which the data are divided into k classes based upon a distance criterion. in the present research, by using k-means method for classifying data derived from exploration boreholes in the parkam deposit, the optimum k has been calculated and then the data have been clustered and the relative geochemical behavioral characteristics analyzed. the c...

How do animals in groups organize their work? Division of labour, i.e. the process by which individuals within a group choose which tasks to perform, has been extensively studied in social insects. Variability among individuals within a colony seems to underpin both the decision over which tasks to perform and the amount of effort to invest in a task. Studies have focused mainly on discrete tas...

We consider a team of k identical, oblivious, and semi-synchronous mobile robots that are able to sense (i.e., view) their environment, yet are unable to communicate, and evolve on a constrained path. Previous results in this weak scenario show that initial symmetry yields high lower bounds when problems are to be solved by deterministic robots. In this paper, we initiate research on probabilis...

Let D be a connected region inside a simple polygon, P . We define the angle hull of D, AH(D), to be the set of all points in P that can see two points of D at a right angle. We show that the perimeter of AH(D) cannot exceed in length the perimeter of D by more than a factor of 2. This upper bound is tight. Our result can be generalized to angles different from 90◦, and to settings where region...