Cotygodniowe seminarium badawcze (brak strony WWW)
2019-03-07, godz. 10:15, 4050
Piotr Skowron (Instytut Informatyki, UW)
Proportionality Degree of Multiwinner Rules
We study multiwinner elections with approval-based preferences. An instance of a multiwinner election consists of a set of alternatives, a population of voters---each voter approves a subset of alternatives, and the desired committee size k; the goal is to select a committee (a subset) of k alternat...
2019-01-24, godz. 10:15, 4050
Michał Godziszewski (Instytut Informatyki, UW)
Judgement Aggregation and Multiwinner Elections
In most general terms, the theory of judgement aggregation (JA) investigates rules for making consistent collective judgements on a set of propositions on the basis of the group members' individual judgements on these propositions. A multiwinner election rule is a formal process for selecting a sub...
2018-12-06, godz. 10:15, 4050
Grzegorz Pierczyński (Instytu)
Approval-based elections and distortion of voting rules
We consider elections where both voters and candidates can be associated with points in a metric space and each voter prefers candidates that are closer to him/her to those that are further away. Such a metric space can be e.g. an issue space of their political views. We will measure the quality...
2018-11-22, godz. 10:15, 4050
Oskar Skibski (Instytut Informatyki, UW)
Attachment Centrality: Properties and Computation
Centrality indices aim to quantify the importance of nodes or edges in a network. Much interest has been recently raised by the body of work in which a node’s connectivity is understood less as its contribution to the quality or speed of communication in the network and more as its role in ena...
2018-11-08, godz. 10:15, 4050
Tomasz Wąs (Instytut Informatyki UW)
We propose a new centrality measure, called the Random Walk Decay centrality. While most centralities in the literature are based on the notion of shortest paths, this new centrality measure stems from the random walk on the network. We provide an axiomatic characterization and show that the new cen...
2018-10-26, godz. 12:15, 4050
Dominik Peters (Department of Computer Science, University of Oxford)
Allocation of Indivisible Items with Connected Bundles
Suppose a collection of indivisible goods are arranged in a line, and we wish to allocate these items to agents so that each agent receives a connected bundle (an interval). This makes sense when the items have a spatial or temporal structure, for example when allocating time slots, and agents are i...
2018-10-18, godz. 10:15, 4050
Marcin Dziubiński (Instytut Informatyki, UW)
We propose and study a strategic model of hiding in a network, where the network designer chooses the links and his position in the network facing the seeker who inspects and disrupts the network. We characterize optimal networks for the hider, as well as equilibrium hiding and seeking strategies on...
2018-05-10, godz. 10:15, 4050
Tomasz Wąs (Instytut Informatyki, UW)
Axiomatization of the PageRank centrality
We propose an axiomatization of PageRank. Specifically, we introduce five simple axioms – Foreseeability, Outgoing Homogeneity, Monotonicity, Merging, and Dummy Node – and show that PageRank is the only centrality measure that satisfies all of them. Our axioms give new conceptual and ...
2018-04-12, godz. 10:15, 4050
Piotr Skowron (Instytut Informatyki UW)
Approximating Optimal Social Choice under Metric Preferences
We consider voting under metric preferences: both voters and alternatives are associated with points in a metric space, and each voter prefers alternatives that are closer to her to ones that are further away. In this setting, it is often desirable to select an alternative that minimizes the sum of ...
2018-03-29, godz. 10:15, 4050
Krzysztof Rządca (Instytut Informatyki, UW)
Collective Schedules: Scheduling Meets Computational Social Choice
When scheduling public works or events in a shared facility one needs to accommodate preferences of a population. We formalize this problem by introducing the notion of a collective schedule. We show how to extend fundamental tools from social choice theory---positional scoring rules, the Kemeny ru...