An n × n complex matrix A is h-pseudo-tournament if A + A∗ = hh∗ − I, where h is a complex, non-zero column vector. The class of h-pseudo-tournament matrices is a generalization of the well studied tournament-like matrices: h-hypertournament matrices, generalized tournament matrices and tournament matrices. In this paper we derive new spectral properties of an h-pseudo-tournament matrix. When t...

A directed graph where there is exactly one edge between every pair of vertices is called a tournament. Finding the “best” set of vertices of a tournament is a well studied problem in social choice theory. A tournament solution takes a tournament as input and outputs a subset of vertices of the input tournament. However, in many applications, for example, choosing the best set of drugs from a g...

We explore the behavior of losers of promotion tournaments after the tournament is concluded. We do so through the use of an experiment in which we vary the design of the promotion tournament to determine how tournament design affects post tournament effort. We provide a theoretical model demonstrating two possible effects from the tournaments which are strategic sabotage and the possibility th...

We study the power of a tournament organizer in manipulating the outcome of a single elimination tournament by fixing the initial seeding. It is not known whether the organizer can efficiently fix the outcome of the tournament even if the match outcomes are known in advance. We generalize a result from prior work by giving a new condition such that the organizer can efficiently find a tournamen...

Tournament outcome uncertainty depends on: the design of the tournament; and the relative strengths of the competitors – the competitive balance. A tournament design comprises the arrangement of the individual matches, which we call the tournament structure, the seeding policy and the progression rules. In this paper, we investigate the effect of seeding policy for various tournament structures...

We study the tournament fixing problem (TFP), which asks whether a tournament organizer can rig a single-elimination (SE) tournament such that their favorite player wins, simply by adjusting the initial seeding. Prior results give two perspectives of TFP: on the one hand, deciding whether an arbitrary player can win any SE tournament is known to be NP-complete; on the other hand, there are a nu...

Abstract. A tournament matrix and its corresponding directed graph both arise as a record of the outcomes of a round robin competition. An n × n complex matrix A is called h-pseudo-tournament if there exists a complex or real nonzero column vector h such that A+ A∗ = hh∗ − I . This class of matrices is a generalisation of well-studied tournament-like matrices such as h-hypertournament matrices,...

Individual willingness to enter competitive environments predicts career choices and labor market outcomes. Meanwhile, many people experience competitive contexts as stressful. We use two laboratory experiments to investigate whether factors related to stress can help explain individual differences in tournament entry. Experiment 1 studies whether stress responses (measured as salivary cortisol...

We propose to deploy the tournament methods to perform the task of email categorization. The multi-class categorization process is thus broken down into a set of binary classification tasks. We implement the elimination tournament and Round Robin tournament and apply them to classify emails within 15 folders. We conduct substantial experiments to compare the effectiveness and robustness of the ...

In this thesis, we investigate several properties of k-tournaments, where k 2 3. These properties fall into three broad areas. The first contains properties related to the ranking of the participants in a k-tournament, including a representation theorem for posets. The second contains properties related to the representation of a finite group as the automorphism group of a k-tournament, with va...