Control and bribery are settings in which an external agent seeks to influence the outcome of an election. Faliszewski et al. [7] proved that Llull voting (which is here denoted by Copeland) and a variant (here denoted by Copeland) of Copeland voting are computationally resistant to many, yet not all, types of constructive control and that they also provide broad resistance to bribery. We study...

Control and bribery are settings in which an external agent seeks to influence the outcome of an election. Faliszewski et al. [7] proved that Llull voting (which is here denoted by Copeland) and a variant (here denoted by Copeland) of Copeland voting are computationally resistant to many, yet not all, types of constructive control and that they also provide broad resistance to bribery. We study...

We study the complexity of manipulation for a family of election systems derived from Copeland voting via introducing a parameter α that describes how ties in head-to-head contests are valued. We show that the thus obtained problem of manipulation for unweighted Copeland elections is NP-complete even if the size of the manipulating coalition is limited to two. Our result holds for all rational ...

Copeland and comprehensive multi-index comparison methods were used to rank and screen hazardous chemicals using original and pre-treatment data sets. The results show that the Copeland method can yield similar results for the two data sets. The results of a comprehensive multi-index comparison with the pretreatment dataset also show some similarities to those obtained using Copeland method. Th...

INTRODUCTION We consider a probabilistic model of round-robin tournaments, or equivalently, Copeland voting, where candidates are the voters. We assume that the outcomes of each game or pairwise vote are jointly independent. In particular, we do not assume that votes arise from voters’ ranked orderings of candidates. We can treat such games as pairwise preferences, without assuming any form of ...

A version of the dueling bandit problem is addressed in which a Condorcet winner may not exist. Two algorithms are proposed that instead seek to minimize regret with respect to the Copeland winner, which, unlike the Condorcet winner, is guaranteed to exist. The first, Copeland Confidence Bound (CCB), is designed for small numbers of arms, while the second, Scalable Copeland Bandits (SCB), works...

We resolve an open problem regarding the complexity of unweighted coalitional manipulation, namely, the complexity of Copeland-manipulation for α ∈ {0, 1}. Copeland, 0 ≤ α ≤ 1, is an election system where for each pair of candidates we check which one is preferred by more voters (i.e., we conduct a head-to-head majority contest) and we give one point to this candidate and zero to the other. How...