Lista referatów

• 2022-11-17, godz. 12:15, 4050

  Piotr Skowron (University of Warsaw)

  Proportional Participatory Budgeting with Additive Utilities

  We study voting rules for participatory budgeting, where a group of voters collectively decides which projects should be funded using a common budget. We allow the projects to have arbitrary costs, and the voters to have arbitrary additive valuations over the projects. We formulate an axiom (Extende...

• 2022-11-03, godz. 12:00, seminarium zdalne

  Łukasz Janeczko (AGH)

  Ties in Multiwinner Approval Voting

  We investigate ties in multiwinner approval voting both theoretically and experimentally. Specifically, we analyze the computational complexity of 1) determining if there is a tie in a given election for a given rule, and 2) the complexity of counting the number of winning committees. We mainly conc...

• 2022-10-20, godz. 12:15, 4050

  Jannik Peters (TU Berlin)

  Proportional Participatory Budgeting with Approval-Based Satisfaction Functions

  The ability to measure the satisfaction of (groups of) voters is a crucial prerequisite for formulating proportionality axioms in approval-based participatory budgeting elections. Two common -- but very different -- ways to measure the satisfaction of a voter consider (i) the number of approved proj...

• 2022-10-13, godz. 12:15, 4050

  Michał Tomasz Godziszewski (University of Warsaw)

  Election control for VCR Euclidean preferences

  Election control problems model situations where some entity (traditionally called the election chair) wants to ensure some agent's victory (the so-called, Constructive Control) or loss (the so-called Destructive Control) by either adding or deleting candidates or voters. Computational propertie...

• 2022-10-06, godz. 12:00, online seminar

  Marcin Dziubiński (University of Warsaw)

  Selecting a Winner with Impartial Referees

  We consider a problem of mechanism design without money, where a planner selects a winner among a set of agents with binary types and receives outside signals (like the report of impartial referees). We show that there is a gap between the optimal Dominant Strategy Incentive Compatible (DSIC) mechan...

• 2022-07-06, godz. 16:00, Spotkanie online

  Stanisław Szufa (AGH University in Kraków)

  Numerical Experiments in Computational Social Choice

  While many papers in computational social choice are theoretical, the number of experimental works is rapidly growing. During the tutorial, we will focus on experiments related to voting and participatory budgeting. We will discuss most popular statistical culture models (that serve for generatin...

• 2022-06-08, godz. 16:00, seminarium zdalne

  Marcin Waniek (New York University Abu Dhabi)

  Social diffusion sources can escape detection

  Influencing (and being influenced by) others through social networks is fundamental to all human societies. Whether this happens through the diffusion of rumors, opinions, or viruses, identifying the diffusion source (i.e., the person that initiated it) is a problem that has attracted much research ...

• 2022-05-26, godz. 10:15, 4050

  Dorota Celińska-Kopczyńska (Instytut Informatyki, UW)

  Non-Euclidean Self-Organizing Maps

  Self-Organizing Maps (SOMs, Kohonen networks) belong to neural network models of the unsupervised class. Most data analysts take it for granted to use some subregions of a flat space as their data model. However, assuming that the underlying geometry is non-Euclidean, we obtain a new degree of freed...

• 2022-05-12, godz. 10:15, 4050

  Michał Jaworski (Uniwersytet Warszawski)

  Phragmen Rules for Degressive and Regressive Proportionality

  We study two concepts of proportionality in the model of approval-based committee elections. In degressive proportionality small minorities of voters are favored in comparison with the standard linear proportionality. Regressive proportionality, on the other hand, requires that larger subdivisions o...

• 2022-04-28, godz. 10:15, 4050

  Dominik Peters (Université Paris Dauphine-PSL)

  Fast Preference Elicitation and Fairness in Voting

  Talk 1: Many decision making systems require users to indicate their preferences via a ranking. It is common to elicit such rankings through pairwise comparison queries. By using sorting algorithms, this can be achieved by asking at most O(m log m) adaptive comparison queries. However, in many ca...

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