Cotygodniowe seminarium badawcze (brak strony WWW)
2021-12-16, godz. 10:15, on-line
Wiktoria Kośny (Instytut Informatyki, UW)
Comparative Theoretical Analysis of Medial Centrality Measures
We study medial centrality measures that assess the role of a node in connecting others in the network. We focus on a setting with one target node t and several source nodes. We consider four classic measures adapted to this setting: Betweenness Centrality, Stress Centrality, Random Walk Betweennes...
2021-12-02, godz. 10:15, 4050
Stanisław Kaźmierowski (Instytut Informatyki, UW)
Computing equilibria in conflicts with multiple battlefields and majoritarian objectives
We consider computation of Nash equilibria in conflicts with multiple battlefields and majoritarian objectives. Conflicts with multiple battlefields are zero-sum two player games with succinct representation: the number of strategies of each player is exponential with respect to the size of the game...
2021-11-18, godz. 10:15, 4050
Jorge Salas (University of Edinburgh)
A family of centrality measures for graph data based on subgraphs
Graph structured data are stored in specialized databases called graph databases. These systems let us efficiently compute queries over the graph such as looking for paths or patterns in it. Conjunctive queries are one kind of commonly used queries for graph databases where you look for patterns as ...
2021-11-04, godz. 10:15, 4050
Oskar Skibski (Instytut Informatyki, UW)
Closeness Centrality via the Condorcet Principle
We uncover a new relation between Closeness centrality and the Condorcet principle. We define a Condorcet winner in a graph as a node that compared to any other node is closer to more nodes. In other words, if we assume that nodes vote on a closer candidate, a Condorcet winner would win a two-candid...
2021-10-21, godz. 10:15, 4050
Krzysztof Apt (Centrum Wiskunde & Informatica, Amsterdam, i Instytut Informatyki, UW)
For the past five years we have been studying a natural class of coordination games. In these games the players are nodes in a (possibly directed), each with a finite set of strategies, and the payoff of each player defined as the number of his neighbours who selected the same strategy. These g...
2021-10-07, godz. 10:15, 4050
Grzegorz Pierczyński (Instytut Informatyki, UW)
Core-Stable Committees under Restricted Domains
We study the setting of committee elections, where a group of individuals needs to collectively select a given size subset of available objects. This model is relevant for a number of real-life scenarios including political elections, participatory budgeting, and facility-location. We focus on the c...
Krzysztof Apt (Centrum Wiskunde & Informatica i Instytut Informatyki, UW)
Well-founded extensive games with perfect information
We consider extensive games with perfect information with well-founded game trees and study the problems of existence and of characterization of the sets of subgame perfect equilibria in these games. We also provide such characterizations for two classes of these games in which subgame perfect equil...
2021-04-29, godz. 10:15, on-line
Marcin Waniek (New York University Abu Dhabi)
Disinformation attacks on cities
Disinformation continues to raise concerns due to its increasing threat to society. Nevertheless, a disinformation-based attack on critical infrastructure has never been studied to date. In this line of work we consider two possible attack scenarios. In the first scenario, we consider urban traffic ...
2021-04-15, godz. 10:15, on-line
Tomasz Wąs (Instytut Informatyki, UW)
An Axiom System for Feedback Centralities
In recent years, the axiomatic approach to centrality measures has attracted attention in the literature. However, most papers propose a collection of axioms dedicated to one or two considered centrality measures. In result, it is hard to capture the differences and similarities between various meas...
2021-03-18, godz. 10:15, on-line
Grzegorz Pierczyński (Instytut Informatyki, UW)
Market-Based Explanations of Collective Decisions
We consider approval-based committee elections, in which a size-k subset of available candidates must be selected given approval sets for each voter, indicating the candidates approved by the voter. A number of axioms capturing ideas of fairness and proportionality have been proposed for this framew...