cover

Cover

Set Cover 1 Unweighted Set Cover

Let X = {x1, ..., xn} be a set, and let P = {P1, ..., Pm} be a set of subsets of X. The goal is to find the smallest sub-collection of sets R ⊆ P whose union covers all of X. More concretely, we can say that each xi, 1 ≤ i ≤ n represents a “skill”, and each Pj, 1 ≤ j ≤ m represents a “person”. In this case, xi ∈ Pj if person Pj has the skill xi. Then, as an employer, the goal is to find the min...

Cover Story and Contents Cover Story

The front cover shows ABB serving the cement manufacturing industry, which it has done since 1961 with turnkey installations, electrical equipment and automation systems. In 1990, ABB recognised the MES (Manufacturing Execution Systems) business area as a natural extension to its technology portfolio. Since then, ABB has provided added value solutions that are independent from the installed pro...