Lista referatów

• 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...

• 2022-04-14, godz. 10:15, 4050

  Tomasz Wąs (Instytut Informatyki, UW)

  Understanding Distance Measures Among Elections

  Motivated by putting empirical work based on (synthetic) election data on a more solid mathematical basis, we analyze six distances among elections, including, e.g., the challenging-to-compute but very precise swap distance and the distance used to form the so-called map of elections. Among the six,...

• 2022-03-31, godz. 10:15, 4050

  Marcin Dziubiński (Instytut Informatyki, UW)

  Discrete Two Player All-Pay Auction with Complete Information

  We study discrete two player all-pay auction with complete information. We provide full characterization of mixed strategy Nash equilibria and show that they constitute a subset of Nash equilibria of discrete General Lotto game. We show that equilibria are not unique in general but they are intercha...

• 2022-03-17, godz. 10:15, 4050

  Adrian Górecki

  Proportional Public Decisions

  We consider a setting where a group of individuals make a number of independent decisions. The decisions should proportionally represent the views of the voters. We formulate new criteria of proportionality and analyse two rules, Proportional Approval Voting and the Metod of Equal Shares, inspired b...

• 2022-03-03, godz. 10:15, 4050

  Balázs Sziklai (Centre for Economic and Regional Studies & Corvinus University of Budapest)

  Expert selection in recommendation networks

  The Weighted Top Candidate (WTC) algorithm is an expert identification method that presents an alternative for network centralities. Its main advantage is its axiomatic characterization that shows why it is especially suitable for a number of applications. The WTC algorithm, upon receiving a reco...

• 2022-01-27, godz. 10:30, 4050

  Michał Godziszewski (Instytut Informatyki, UW)

  Attacking Similarity-Based Sign Prediction

  Adversarial social network analysis explores how social links can be altered or otherwise manipulated to obscure unwanted information collection. Thus far, however, problems of this kind have not been studied in the context of signed networks in which links have positive and negative labels. Such fo...

• 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...

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