Cotygodniowe seminarium badawcze (brak strony WWW)
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...
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
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...