Weekly research seminar

2023-01-12, 12:15, 4050

Michał Pawłowski (University of Warsaw)

**Optimizing ride-hailing fares using computational microeconomy tools**Pricing ride-hailing fares sparked a rich line of work in computer science due to its complexity and multidimensionality of aspects. We add to this line of research by considering the model presented by Hikima et al. (AAAI, 2021). For this model, the authors claimed a 3-approximation of the optimum ...

2023-01-05, 12:00, spotkanie online

Piotr Faliszewski (AGH University in Kraków)

**Map of Elections: Diversity, Polarization, and Agreement In Elections (+ some more)**In this talk I will present the idea of the map of (ordinal) elections and argue what it is good for. First, we will spend considerable amount of time on understanding diversity, polarization, and agreement within elections on the map. Then, we will look at other applications, such as using the map ...

2022-12-15, 12:15, 4050

Stanisław Kaźmierowski (University of Warsaw)

**Algorithm for solving the attack and interception game on networks**The paper "Attack and interception in networks" (F. Bloch, K. Chatterjee, B. Dutta, 2022), describes a game where a single attacker chooses a target and a path and each node chooses a level of protection. Main results proposed in this paper are the existence and uniqueness of NE of the pro...

2022-12-08, 12:00, seminarium zdalne

Piotr Skowron (Uniwersytet Warszawski)

**Proportionality in General Social Choice Models**We consider a model where a number of candidates need to be selected subject to certain feasibility constraints. The model generalises committee elections (where there is a single constraint on the number of candidates that need to be selected), various elections with diversity constraints, the mode...

2022-11-17, 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, 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, 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, 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, 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, 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...