Cotygodniowe seminarium badawcze (brak strony WWW)
2017-05-11, godz. 10:15, 1780
Oskar Skibski (Instytut Informatyki, UW)
Axiomatic Characterization of Distance-based Centralities
I will present our initial results concerning the characterization of the distance-based centralities. First, we characterize distance based centralities using Sabidussi's operations of adding and moving edges. Then, by adding one axiom we obtain a natural class of additive distance-based centraliti...
2017-04-20, godz. 10:15, 1780
Tomasz Michalak (Instytut Informatyki, UW)
Strategic Social Network Analysis
How can individuals and communities protect their privacy against graph-theoretic network analysis tools? How do criminals or terrorists organizations evade detection by such tools? Under which conditions can these tools be made strategy proof? These fundamental questions have attracted little atte...
2017-04-06, godz. 10:15, 1780
Marcin Waniek (Instytut Informatyki, UW)
On the Construction of Covert Networks
Centrality measures are widely used to identify leaders of covert networks. We study how a group of such leaders can avoid being detected. In more detail, we study the hardness of modifying the network in order to decrease the leaders' ranking positions according to three fundamental centrality meas...
2017-03-30, godz. 10:15, 1780
Marcin Dziubiński (Instytut Informatyki, UW)
Spectrum of equilibria in Colonel Blotto game
We study Nash equilibria of a symmetric Colonel Blotto game. In this game two players, with N≥1 units of resources each, distribute their resources simultaneously across K≥2 battlefields. We introduce a characteristic of equilibria in this game called spectrum which stands for the fraction of ba...
2017-03-09, godz. 10:15, 1780
Oskar Skibski (Instytut Informatyki, UW)
Axiomatic Characterization of Game-Theoretic Network Centralities
In this work, we focus on the game-theoretic approach to centrality analysis. While various centrality indices have been proposed based on this approach, it is still unknown what distinguishes this family of indices from the more classical ones. In this paper, we answer this question by providing th...
2017-01-12, godz. 10:15, 1780
Marcin Dziubiński (Instytut Informatyki, UW)
Players are endowed with resources. A player can engage in conflict with others to enlarge his resources. The set of potential conflicts is defined by a contiguity network. Players are farsighted and aim to maximize their resources. They decide on whether to wage war or remain peaceful. The winner o...
2016-12-15, godz. 10:15, 1780
Piotr Dworczak (Stanford University)
Mechanism Design with Aftermarkets
I study a model of mechanism design in which the mechanism is followed by an aftermarket, that is, a post-mechanism game played between the agent and other market participants. The designer has preferences that depend on the final outcome but she cannot directly redesign the aftermarket. However, sh...
2016-12-01, godz. 10:15, 1780
Piotr Skowron (University of Oxford)
Multiwinner Election Rules: Axioms and Applications
We consider multiwinner election rules and discuss some of their properties. In particular we discuss the concept of proportional representation of multiwinner election rules. Informally, proportional representation requires that the extent to which a particular preference or opinion is represen...
2016-10-27, godz. 10:15, 1780
Marcin Waniek (Instytut Informatyki UW)
On Hiding Communities and Evading Link Prediction in Social Networks
Community detection and link prediction are two of the main research problems in social network analysis. While various private and public institutions are interested in identifying communities, it raises serious privacy issues as well as security-related concerns. We introduce the problem of hid...
2016-10-13, godz. 10:15, 1780
Takamasa Suzuki (Kyushu University)
Efficient assignment mechanism with endowments and distributional constraints
We consider an assignment problem of multiple types goods to agents, where each type of a good has multiple copies (e.g., multiple seats of a school). Each agent is endowed with a good. Some distributional constraints are imposed on the allocation (e.g., minimum/maximum quotas, the balance of r...