REPORT OF THE HONORARY SECRETARIES, 1910

Matroid Secretaries

We prove that for every proper minor-closed class M of Fp-representable matroids, there exists a O(1)-competitive algorithm for the matroid secretary problem on M. This result relies on the extremely powerful matroid minor structure theory being developed by Geelen, Gerards and Whittle. We also note that for asymptotically almost all matroids, the matroid secretary algorithm that selects a rand...

The information behaviour of secretaries

Partially ordered secretaries

The elements of a finite nonempty partially ordered set are exposed at independent uniform times in [0,1] to a selector who, at any given time, can see the structure of the induced partial order on the exposed elements. The selector’s task is to choose online a maximal element. This generalizes the classical linear order secretary problem, for which it is known that the selector can succeed wit...

Online hypergraph matching: hiring teams of secretaries

The goal of this paper is to find a competitive algorithm for the following problem. We are given a hypergraph G = (X,E), |E| = n, with weighted edges and maximum edge size k. We wish to maximize the weight of a matching M ⊆ E of G, given that edges are revealed in a random order, and that when an edge e is revealed the algorithm must decide either e ∈ M or e / ∈M . Note that this is a generali...

Truthful Secretaries with Budgets

We study online auction settings in which agents arrive and depart dynamically in a random (secretary) order, and each agent’s private type consists of the agent’s arrival and departure times, value and budget. We consider multi-unit auctions with additive agents for the allocation of both divisible and indivisible items. For both settings, we devise truthful mechanisms that give a constant app...