The rank aggregation problem has received significant recent attention within the computer science community. Its applications today range far beyond the original aim of building metasearch engines to problems in machine learning, recommendation systems and more. Several algorithms have been proposed for these problems, and in many cases approximation guarantees have been proven for them. Howev...

We study theK-armed dueling bandit problem, a variation of the standard stochastic bandit problem where the feedback is limited to relative comparisons of a pair of arms. The hardness of recommending Copeland winners, the arms that beat the greatest number of other arms, is characterized by deriving an asymptotic regret bound. We propose Copeland Winners Relative Minimum Empirical Divergence (C...

1. BASSOE, P. AND NUZUM, F. (1915): Jour. Nerv. and Mental Disease, xlii, 785. 2. COPELAND (1935): Amer. Jour. Cancer, xxiv, 751. 3. CZERNY: Quoted by Ewing, "Neoplastic Diseases." 4. FERGUSON: Quoted by Copeland. 5. HERXHEIMER AND ROTH (1914): Zeigler Beit., Iviii, 319. 6. HARBITZ, F. (1909): Arch. Int. Med., iii, 32. 7. KAUFMANN: Pathology, vol. iii (translated by Reiman), London (1929). 8. K...

We study the complexity of Destructive Shift Bribery. In this problem, we are given an election with a set of candidates and a set of voters (ranking the candidates from best to worst, each), a despised candidate d (typically, one of the current winners), a budget B, and prices for shifting d down in voters’ rankings. The goal is to ensure that d is not a winner of the election. We show that th...

Complexity of voting manipulation is a prominent research topic in computational social choice. The voting manipulation literature usually assumes that the manipulator is only concerned with improving the outcome of the election from her perspective. However, in practice, the manipulator may also be reluctant to lie, i.e., she may have a preference for submitting a vote that does not deviate to...

To my parents and sister, for everything. iii ACKNOWLEDGEMENTS It is my pleasure to give my sincere thanks to all the people who have supported and helped me during the pursuit of my Ph.D. degree. Without their encouragement, I would not have completed this dissertation. First of all, I would like to express my deep gratitude to my dissertation advisor, Dr. John A. Copeland, for his constant su...

(1001) From Encoding to Retention to Recognition. MICHAEL J. WENGER & ANGELINA M. COPELAND, University of Notre Dame—The perception of meaningful, organized visual forms, such as human faces, has been hypothesized to result in an encoded representation that possesses a high degree of dependence among the constituent elements. In contrast, the perception of such forms as common objects is though...