[{"_id":"1138","status":"public","type":"conference","conference":{"name":"LICS: Logic in Computer Science","start_date":"2016-07-05","end_date":"2016-07-08","location":"New York, NY, USA"},"date_updated":"2021-01-12T06:48:34Z","department":[{"_id":"KrCh"},{"_id":"ToHe"}],"oa_version":"Preprint","abstract":[{"lang":"eng","text":"Automata with monitor counters, where the transitions do not depend on counter values, and nested weighted automata are two expressive automata-theoretic frameworks for quantitative properties. For a well-studied and wide class of quantitative functions, we establish that automata with monitor counters and nested weighted automata are equivalent. We study for the first time such quantitative automata under probabilistic semantics. We show that several problems that are undecidable for the classical questions of emptiness and universality become decidable under the probabilistic semantics. We present a complete picture of decidability for such automata, and even an almost-complete picture of computational complexity, for the probabilistic questions we consider. © 2016 ACM."}],"month":"07","scopus_import":1,"main_file_link":[{"url":"https://arxiv.org/abs/1604.06764","open_access":"1"}],"language":[{"iso":"eng"}],"publication_status":"published","ec_funded":1,"project":[{"grant_number":"267989","name":"Quantitative Reactive Modeling","call_identifier":"FP7","_id":"25EE3708-B435-11E9-9278-68D0E5697425"},{"grant_number":"S 11407_N23","name":"Rigorous Systems Engineering","call_identifier":"FWF","_id":"25832EC2-B435-11E9-9278-68D0E5697425"},{"_id":"25F42A32-B435-11E9-9278-68D0E5697425","call_identifier":"FWF","grant_number":"Z211","name":"The Wittgenstein Prize"},{"grant_number":"P 23499-N23","name":"Modern Graph Algorithmic Techniques in Formal Verification","_id":"2584A770-B435-11E9-9278-68D0E5697425","call_identifier":"FWF"},{"call_identifier":"FP7","_id":"2581B60A-B435-11E9-9278-68D0E5697425","grant_number":"279307","name":"Quantitative Graph Games: Theory and Applications"},{"_id":"25892FC0-B435-11E9-9278-68D0E5697425","name":"Efficient Algorithms for Computer Aided Verification","grant_number":"ICT15-003"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","citation":{"mla":"Chatterjee, Krishnendu, et al. “Quantitative Automata under Probabilistic Semantics.” Proceedings of the 31st Annual ACM/IEEE Symposium, IEEE, 2016, pp. 76–85, doi:10.1145/2933575.2933588.","ieee":"K. Chatterjee, T. A. Henzinger, and J. Otop, “Quantitative automata under probabilistic semantics,” in Proceedings of the 31st Annual ACM/IEEE Symposium, New York, NY, USA, 2016, pp. 76–85.","short":"K. Chatterjee, T.A. Henzinger, J. Otop, in:, Proceedings of the 31st Annual ACM/IEEE Symposium, IEEE, 2016, pp. 76–85.","apa":"Chatterjee, K., Henzinger, T. A., & Otop, J. (2016). Quantitative automata under probabilistic semantics. In Proceedings of the 31st Annual ACM/IEEE Symposium (pp. 76–85). New York, NY, USA: IEEE. https://doi.org/10.1145/2933575.2933588","ama":"Chatterjee K, Henzinger TA, Otop J. Quantitative automata under probabilistic semantics. In: Proceedings of the 31st Annual ACM/IEEE Symposium. IEEE; 2016:76-85. doi:10.1145/2933575.2933588","chicago":"Chatterjee, Krishnendu, Thomas A Henzinger, and Jan Otop. “Quantitative Automata under Probabilistic Semantics.” In Proceedings of the 31st Annual ACM/IEEE Symposium, 76–85. IEEE, 2016. https://doi.org/10.1145/2933575.2933588.","ista":"Chatterjee K, Henzinger TA, Otop J. 2016. Quantitative automata under probabilistic semantics. Proceedings of the 31st Annual ACM/IEEE Symposium. LICS: Logic in Computer Science, 76–85."},"title":"Quantitative automata under probabilistic semantics","publist_id":"6220","author":[{"orcid":"0000-0002-4561-241X","full_name":"Chatterjee, Krishnendu","last_name":"Chatterjee","first_name":"Krishnendu","id":"2E5DCA20-F248-11E8-B48F-1D18A9856A87"},{"id":"40876CD8-F248-11E8-B48F-1D18A9856A87","first_name":"Thomas A","last_name":"Henzinger","orcid":"0000−0002−2985−7724","full_name":"Henzinger, Thomas A"},{"first_name":"Jan","id":"2FC5DA74-F248-11E8-B48F-1D18A9856A87","full_name":"Otop, Jan","last_name":"Otop"}],"external_id":{"arxiv":["1604.06764"]},"acknowledgement":"This research was funded in part by the European Research Council (ERC) under grant agreement 267989 (QUAREM), by the Austrian Science Fund (FWF) projects S11402-N23 (RiSE) and Z211-N23 (Wittgenstein Award), FWF Grant No P23499- N23, FWF NFN Grant No S114","quality_controlled":"1","publisher":"IEEE","oa":1,"day":"05","publication":"Proceedings of the 31st Annual ACM/IEEE Symposium","year":"2016","doi":"10.1145/2933575.2933588","date_published":"2016-07-05T00:00:00Z","date_created":"2018-12-11T11:50:21Z","page":"76 - 85"},{"month":"07","alternative_title":["Proceedings Symposium on Logic in Computer Science"],"scopus_import":"1","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1602.02670"}],"oa_version":"Preprint","abstract":[{"text":"Given a model of a system and an objective, the model-checking question asks whether the model satisfies the objective. We study polynomial-time problems in two classical models, graphs and Markov Decision Processes (MDPs), with respect to several fundamental -regular objectives, e.g., Rabin and Streett objectives. For many of these problems the best-known upper bounds are quadratic or cubic, yet no super-linear lower bounds are known. In this work our contributions are two-fold: First, we present several improved algorithms, and second, we present the first conditional super-linear lower bounds based on widely believed assumptions about the complexity of CNF-SAT and combinatorial Boolean matrix multiplication. A separation result for two models with respect to an objective means a conditional lower bound for one model that is strictly higher than the existing upper bound for the other model, and similarly for two objectives with respect to a model. Our results establish the following separation results: (1) A separation of models (graphs and MDPs) for disjunctive queries of reachability and Büchi objectives. (2) Two kinds of separations of objectives, both for graphs and MDPs, namely, (2a) the separation of dual objectives such as Streett/Rabin objectives, and (2b) the separation of conjunction and disjunction of multiple objectives of the same type such as safety, Büchi, and coBüchi. In summary, our results establish the first model and objective separation results for graphs and MDPs for various classical -regular objectives. Quite strikingly, we establish conditional lower bounds for the disjunction of objectives that are strictly higher than the existing upper bounds for the conjunction of the same objectives. © 2016 ACM.","lang":"eng"}],"language":[{"iso":"eng"}],"publication_status":"published","status":"public","type":"conference","conference":{"location":"New York, NY, USA","end_date":"2016-07-08","start_date":"2016-07-05","name":"LICS: Logic in Computer Science"},"_id":"1140","department":[{"_id":"KrCh"}],"date_updated":"2022-09-09T11:46:17Z","publisher":"IEEE","quality_controlled":"1","oa":1,"acknowledgement":"K. C., M. H., and W. D. are partially supported by the Vienna\r\nScience and Technology Fund (WWTF) through project ICT15-003.\r\nK. C. is partially supported by the Austrian Science Fund (FWF)\r\nNFN Grant No S11407-N23 (RiSE/SHiNE) and an ERC Start grant\r\n(279307: Graph Games). For W. D., M. H., and V. L. the research\r\nleading to these results has received funding from the European\r\nResearch Council under the European Union’s Seventh Framework\r\nProgramme (FP/2007-2013) / ERC Grant Agreement no. 340506.","doi":"10.1145/2933575.2935304","date_published":"2016-07-05T00:00:00Z","date_created":"2018-12-11T11:50:22Z","page":"197 - 206","day":"05","publication":"Proceedings of the 31st Annual ACM/IEEE Symposium on Logic in Computer Science","year":"2016","project":[{"call_identifier":"FWF","_id":"25832EC2-B435-11E9-9278-68D0E5697425","grant_number":"S 11407_N23","name":"Rigorous Systems Engineering"},{"name":"Efficient Algorithms for Computer Aided Verification","grant_number":"ICT15-003","_id":"25892FC0-B435-11E9-9278-68D0E5697425"}],"title":"Model and objective separation with conditional lower bounds: disjunction is harder than conjunction","author":[{"last_name":"Chatterjee","full_name":"Chatterjee, Krishnendu","orcid":"0000-0002-4561-241X","id":"2E5DCA20-F248-11E8-B48F-1D18A9856A87","first_name":"Krishnendu"},{"first_name":"Wolfgang","last_name":"Dvoák","full_name":"Dvoák, Wolfgang"},{"id":"540c9bbd-f2de-11ec-812d-d04a5be85630","first_name":"Monika H","last_name":"Henzinger","full_name":"Henzinger, Monika H","orcid":"0000-0002-5008-6530"},{"first_name":"Veronika","last_name":"Loitzenbauer","full_name":"Loitzenbauer, Veronika"}],"publist_id":"6219","article_processing_charge":"No","external_id":{"arxiv":["1602.02670"]},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","citation":{"mla":"Chatterjee, Krishnendu, et al. “Model and Objective Separation with Conditional Lower Bounds: Disjunction Is Harder than Conjunction.” Proceedings of the 31st Annual ACM/IEEE Symposium on Logic in Computer Science, IEEE, 2016, pp. 197–206, doi:10.1145/2933575.2935304.","short":"K. Chatterjee, W. Dvoák, M.H. Henzinger, V. Loitzenbauer, in:, Proceedings of the 31st Annual ACM/IEEE Symposium on Logic in Computer Science, IEEE, 2016, pp. 197–206.","ieee":"K. Chatterjee, W. Dvoák, M. H. Henzinger, and V. Loitzenbauer, “Model and objective separation with conditional lower bounds: disjunction is harder than conjunction,” in Proceedings of the 31st Annual ACM/IEEE Symposium on Logic in Computer Science, New York, NY, USA, 2016, pp. 197–206.","apa":"Chatterjee, K., Dvoák, W., Henzinger, M. H., & Loitzenbauer, V. (2016). Model and objective separation with conditional lower bounds: disjunction is harder than conjunction. In Proceedings of the 31st Annual ACM/IEEE Symposium on Logic in Computer Science (pp. 197–206). New York, NY, USA: IEEE. https://doi.org/10.1145/2933575.2935304","ama":"Chatterjee K, Dvoák W, Henzinger MH, Loitzenbauer V. Model and objective separation with conditional lower bounds: disjunction is harder than conjunction. In: Proceedings of the 31st Annual ACM/IEEE Symposium on Logic in Computer Science. IEEE; 2016:197-206. doi:10.1145/2933575.2935304","chicago":"Chatterjee, Krishnendu, Wolfgang Dvoák, Monika H Henzinger, and Veronika Loitzenbauer. “Model and Objective Separation with Conditional Lower Bounds: Disjunction Is Harder than Conjunction.” In Proceedings of the 31st Annual ACM/IEEE Symposium on Logic in Computer Science, 197–206. IEEE, 2016. https://doi.org/10.1145/2933575.2935304.","ista":"Chatterjee K, Dvoák W, Henzinger MH, Loitzenbauer V. 2016. Model and objective separation with conditional lower bounds: disjunction is harder than conjunction. Proceedings of the 31st Annual ACM/IEEE Symposium on Logic in Computer Science. LICS: Logic in Computer Science, Proceedings Symposium on Logic in Computer Science, , 197–206."}},{"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1604.05090v1"}],"oa":1,"scopus_import":1,"publisher":"AAAI Press","quality_controlled":"1","month":"01","abstract":[{"text":"Balanced knockout tournaments are ubiquitous in sports competitions and are also used in decisionmaking and elections. The traditional computational question, that asks to compute a draw (optimal draw) that maximizes the winning probability for a distinguished player, has received a lot of attention. Previous works consider the problem where the pairwise winning probabilities are known precisely, while we study how robust is the winning probability with respect to small errors in the pairwise winning probabilities. First, we present several illuminating examples to establish: (a) there exist deterministic tournaments (where the pairwise winning probabilities are 0 or 1) where one optimal draw is much more robust than the other; and (b) in general, there exist tournaments with slightly suboptimal draws that are more robust than all the optimal draws. The above examples motivate the study of the computational problem of robust draws that guarantee a specified winning probability. Second, we present a polynomial-time algorithm for approximating the robustness of a draw for sufficiently small errors in pairwise winning probabilities, and obtain that the stated computational problem is NP-complete. We also show that two natural cases of deterministic tournaments where the optimal draw could be computed in polynomial time also admit polynomial-time algorithms to compute robust optimal draws.","lang":"eng"}],"oa_version":"Preprint","page":"172 - 179","date_created":"2018-12-11T11:50:35Z","ec_funded":1,"volume":"2016-January","date_published":"2016-01-01T00:00:00Z","related_material":{"link":[{"url":"https://www.ijcai.org/proceedings/2016","relation":"table_of_contents"}]},"year":"2016","publication_status":"published","language":[{"iso":"eng"}],"day":"01","conference":{"name":"IJCAI: International Joint Conference on Artificial Intelligence","start_date":"2016-07-09","end_date":"2016-07-15","location":"New York, NY, USA"},"type":"conference","status":"public","project":[{"_id":"25832EC2-B435-11E9-9278-68D0E5697425","call_identifier":"FWF","grant_number":"S 11407_N23","name":"Rigorous Systems Engineering"},{"name":"Efficient Algorithms for Computer Aided Verification","grant_number":"ICT15-003","_id":"25892FC0-B435-11E9-9278-68D0E5697425"},{"grant_number":"279307","name":"Quantitative Graph Games: Theory and Applications","call_identifier":"FP7","_id":"2581B60A-B435-11E9-9278-68D0E5697425"},{"grant_number":"267989","name":"Quantitative Reactive Modeling","_id":"25EE3708-B435-11E9-9278-68D0E5697425","call_identifier":"FP7"}],"_id":"1182","publist_id":"6171","author":[{"id":"2E5DCA20-F248-11E8-B48F-1D18A9856A87","first_name":"Krishnendu","orcid":"0000-0002-4561-241X","full_name":"Chatterjee, Krishnendu","last_name":"Chatterjee"},{"id":"3B699956-F248-11E8-B48F-1D18A9856A87","first_name":"Rasmus","orcid":"0000-0003-4783-0389","full_name":"Ibsen-Jensen, Rasmus","last_name":"Ibsen-Jensen"},{"full_name":"Tkadlec, Josef","orcid":"0000-0002-1097-9684","last_name":"Tkadlec","id":"3F24CCC8-F248-11E8-B48F-1D18A9856A87","first_name":"Josef"}],"title":"Robust draws in balanced knockout tournaments","department":[{"_id":"KrCh"}],"date_updated":"2023-02-21T10:04:26Z","citation":{"ieee":"K. Chatterjee, R. Ibsen-Jensen, and J. Tkadlec, “Robust draws in balanced knockout tournaments,” presented at the IJCAI: International Joint Conference on Artificial Intelligence, New York, NY, USA, 2016, vol. 2016–January, pp. 172–179.","short":"K. Chatterjee, R. Ibsen-Jensen, J. Tkadlec, in:, AAAI Press, 2016, pp. 172–179.","apa":"Chatterjee, K., Ibsen-Jensen, R., & Tkadlec, J. (2016). Robust draws in balanced knockout tournaments (Vol. 2016–January, pp. 172–179). Presented at the IJCAI: International Joint Conference on Artificial Intelligence, New York, NY, USA: AAAI Press.","ama":"Chatterjee K, Ibsen-Jensen R, Tkadlec J. Robust draws in balanced knockout tournaments. In: Vol 2016-January. AAAI Press; 2016:172-179.","mla":"Chatterjee, Krishnendu, et al. Robust Draws in Balanced Knockout Tournaments. Vol. 2016–January, AAAI Press, 2016, pp. 172–79.","ista":"Chatterjee K, Ibsen-Jensen R, Tkadlec J. 2016. Robust draws in balanced knockout tournaments. IJCAI: International Joint Conference on Artificial Intelligence vol. 2016–January, 172–179.","chicago":"Chatterjee, Krishnendu, Rasmus Ibsen-Jensen, and Josef Tkadlec. “Robust Draws in Balanced Knockout Tournaments,” 2016–January:172–79. AAAI Press, 2016."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87"},{"publist_id":"6150","author":[{"first_name":"Christian","id":"2FDF8F3C-F248-11E8-B48F-1D18A9856A87","full_name":"Hilbe, Christian","orcid":"0000-0001-5116-955X","last_name":"Hilbe"},{"last_name":"Traulsen","full_name":"Traulsen, Arne","first_name":"Arne"}],"title":"Only the combination of mathematics and agent based simulations can leverage the full potential of evolutionary modeling: Comment on “Evolutionary game theory using agent-based methods” by C. Adami, J. Schossau and A. Hintze","citation":{"apa":"Hilbe, C., & Traulsen, A. (2016). Only the combination of mathematics and agent based simulations can leverage the full potential of evolutionary modeling: Comment on “Evolutionary game theory using agent-based methods” by C. Adami, J. Schossau and A. Hintze. Physics of Life Reviews. Elsevier. https://doi.org/10.1016/j.plrev.2016.10.004","ama":"Hilbe C, Traulsen A. Only the combination of mathematics and agent based simulations can leverage the full potential of evolutionary modeling: Comment on “Evolutionary game theory using agent-based methods” by C. Adami, J. Schossau and A. Hintze. Physics of Life Reviews. 2016;19:29-31. doi:10.1016/j.plrev.2016.10.004","ieee":"C. Hilbe and A. Traulsen, “Only the combination of mathematics and agent based simulations can leverage the full potential of evolutionary modeling: Comment on ‘Evolutionary game theory using agent-based methods’ by C. Adami, J. Schossau and A. Hintze,” Physics of Life Reviews, vol. 19. Elsevier, pp. 29–31, 2016.","short":"C. Hilbe, A. Traulsen, Physics of Life Reviews 19 (2016) 29–31.","mla":"Hilbe, Christian, and Arne Traulsen. “Only the Combination of Mathematics and Agent Based Simulations Can Leverage the Full Potential of Evolutionary Modeling: Comment on ‘Evolutionary Game Theory Using Agent-Based Methods’ by C. Adami, J. Schossau and A. Hintze.” Physics of Life Reviews, vol. 19, Elsevier, 2016, pp. 29–31, doi:10.1016/j.plrev.2016.10.004.","ista":"Hilbe C, Traulsen A. 2016. Only the combination of mathematics and agent based simulations can leverage the full potential of evolutionary modeling: Comment on “Evolutionary game theory using agent-based methods” by C. Adami, J. Schossau and A. Hintze. Physics of Life Reviews. 19, 29–31.","chicago":"Hilbe, Christian, and Arne Traulsen. “Only the Combination of Mathematics and Agent Based Simulations Can Leverage the Full Potential of Evolutionary Modeling: Comment on ‘Evolutionary Game Theory Using Agent-Based Methods’ by C. Adami, J. Schossau and A. Hintze.” Physics of Life Reviews. Elsevier, 2016. https://doi.org/10.1016/j.plrev.2016.10.004."},"user_id":"3E5EF7F0-F248-11E8-B48F-1D18A9856A87","project":[{"_id":"25681D80-B435-11E9-9278-68D0E5697425","call_identifier":"FP7","name":"International IST Postdoc Fellowship Programme","grant_number":"291734"}],"page":"29 - 31","date_created":"2018-12-11T11:50:40Z","doi":"10.1016/j.plrev.2016.10.004","date_published":"2016-12-01T00:00:00Z","year":"2016","has_accepted_license":"1","publication":"Physics of Life Reviews","day":"01","oa":1,"quality_controlled":"1","publisher":"Elsevier","acknowledgement":"C.H. acknowledges generous support from the ISTFELLOW program.","file_date_updated":"2020-07-14T12:44:39Z","department":[{"_id":"KrCh"}],"date_updated":"2021-01-12T06:49:03Z","ddc":["530"],"tmp":{"short":"CC BY-NC-ND (4.0)","name":"Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)","legal_code_url":"https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode","image":"/images/cc_by_nc_nd.png"},"type":"journal_article","pubrep_id":"798","status":"public","_id":"1200","ec_funded":1,"volume":19,"publication_status":"published","language":[{"iso":"eng"}],"file":[{"checksum":"95e6dc78278334b99dacbf8822509364","file_id":"4855","content_type":"application/pdf","relation":"main_file","access_level":"open_access","file_name":"IST-2017-798-v1+1_comment_adami.pdf","date_created":"2018-12-12T10:11:02Z","file_size":171352,"date_updated":"2020-07-14T12:44:39Z","creator":"system"}],"scopus_import":1,"intvolume":" 19","month":"12","oa_version":"Submitted Version"},{"ec_funded":1,"volume":26,"issue":"Februar-2016","language":[{"iso":"eng"}],"publication_status":"published","intvolume":" 26","month":"02","scopus_import":1,"oa_version":"None","abstract":[{"text":"To facilitate collaboration in massive online classrooms, instructors must make many decisions. For instance, the following parameters need to be decided when designing a peer-feedback system where students review each others' essays: the number of students each student must provide feedback to, an algorithm to map feedback providers to receivers, constraints that ensure students do not become free-riders (receiving feedback but not providing it), the best times to receive feedback to improve learning etc. While instructors can answer these questions by running experiments or invoking past experience, game-theoretic models with data from online learning platforms can identify better initial designs for further improvements. As an example, we explore the design space of a peer feedback system by modeling it using game theory. Our simulations show that incentivizing students to provide feedback requires the value obtained from receiving a feedback to exceed the cost of providing it by a large factor (greater than 7). Furthermore, hiding feedback from low-effort students incentivizes them to provide more feedback.","lang":"eng"}],"department":[{"_id":"KrCh"}],"date_updated":"2021-01-12T06:49:22Z","status":"public","conference":{"start_date":"2016-02-26","location":"San Francisco, CA, USA","end_date":"2016-03-02","name":"CSCW: Computer Supported Cooperative Work and Social Computing"},"type":"conference","_id":"1245","date_created":"2018-12-11T11:50:55Z","date_published":"2016-02-27T00:00:00Z","doi":"10.1145/2818052.2869122","page":"365 - 368","publication":"Proceedings of the ACM Conference on Computer Supported Cooperative Work","day":"27","year":"2016","publisher":"ACM","quality_controlled":"1","acknowledgement":"ERC Start Grant Graph Games 279307 supported this research. ","title":"Game-theoretic models identify useful principles for peer collaboration in online learning platforms","publist_id":"6083","author":[{"last_name":"Pandey","full_name":"Pandey, Vineet","first_name":"Vineet"},{"id":"2E5DCA20-F248-11E8-B48F-1D18A9856A87","first_name":"Krishnendu","full_name":"Chatterjee, Krishnendu","orcid":"0000-0002-4561-241X","last_name":"Chatterjee"}],"user_id":"3E5EF7F0-F248-11E8-B48F-1D18A9856A87","citation":{"chicago":"Pandey, Vineet, and Krishnendu Chatterjee. “Game-Theoretic Models Identify Useful Principles for Peer Collaboration in Online Learning Platforms.” In Proceedings of the ACM Conference on Computer Supported Cooperative Work, 26:365–68. ACM, 2016. https://doi.org/10.1145/2818052.2869122.","ista":"Pandey V, Chatterjee K. 2016. Game-theoretic models identify useful principles for peer collaboration in online learning platforms. Proceedings of the ACM Conference on Computer Supported Cooperative Work. CSCW: Computer Supported Cooperative Work and Social Computing vol. 26, 365–368.","mla":"Pandey, Vineet, and Krishnendu Chatterjee. “Game-Theoretic Models Identify Useful Principles for Peer Collaboration in Online Learning Platforms.” Proceedings of the ACM Conference on Computer Supported Cooperative Work, vol. 26, no. Februar-2016, ACM, 2016, pp. 365–68, doi:10.1145/2818052.2869122.","ama":"Pandey V, Chatterjee K. Game-theoretic models identify useful principles for peer collaboration in online learning platforms. In: Proceedings of the ACM Conference on Computer Supported Cooperative Work. Vol 26. ACM; 2016:365-368. doi:10.1145/2818052.2869122","apa":"Pandey, V., & Chatterjee, K. (2016). Game-theoretic models identify useful principles for peer collaboration in online learning platforms. In Proceedings of the ACM Conference on Computer Supported Cooperative Work (Vol. 26, pp. 365–368). San Francisco, CA, USA: ACM. https://doi.org/10.1145/2818052.2869122","short":"V. Pandey, K. Chatterjee, in:, Proceedings of the ACM Conference on Computer Supported Cooperative Work, ACM, 2016, pp. 365–368.","ieee":"V. Pandey and K. Chatterjee, “Game-theoretic models identify useful principles for peer collaboration in online learning platforms,” in Proceedings of the ACM Conference on Computer Supported Cooperative Work, San Francisco, CA, USA, 2016, vol. 26, no. Februar-2016, pp. 365–368."},"project":[{"grant_number":"279307","name":"Quantitative Graph Games: Theory and Applications","call_identifier":"FP7","_id":"2581B60A-B435-11E9-9278-68D0E5697425"}]},{"citation":{"chicago":"Brázdil, Tomáš, Vojtěch Forejt, Antonín Kučera, and Petr Novotný. “Stability in Graphs and Games,” Vol. 59. Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2016. https://doi.org/10.4230/LIPIcs.CONCUR.2016.10.","ista":"Brázdil T, Forejt V, Kučera A, Novotný P. 2016. Stability in graphs and games. CONCUR: Concurrency Theory, LIPIcs, vol. 59, 10.","mla":"Brázdil, Tomáš, et al. Stability in Graphs and Games. Vol. 59, 10, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2016, doi:10.4230/LIPIcs.CONCUR.2016.10.","apa":"Brázdil, T., Forejt, V., Kučera, A., & Novotný, P. (2016). Stability in graphs and games (Vol. 59). Presented at the CONCUR: Concurrency Theory, Quebec City, Canada: Schloss Dagstuhl - Leibniz-Zentrum für Informatik. https://doi.org/10.4230/LIPIcs.CONCUR.2016.10","ama":"Brázdil T, Forejt V, Kučera A, Novotný P. Stability in graphs and games. In: Vol 59. Schloss Dagstuhl - Leibniz-Zentrum für Informatik; 2016. doi:10.4230/LIPIcs.CONCUR.2016.10","ieee":"T. Brázdil, V. Forejt, A. Kučera, and P. Novotný, “Stability in graphs and games,” presented at the CONCUR: Concurrency Theory, Quebec City, Canada, 2016, vol. 59.","short":"T. Brázdil, V. Forejt, A. Kučera, P. Novotný, in:, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2016."},"user_id":"3E5EF7F0-F248-11E8-B48F-1D18A9856A87","author":[{"first_name":"Tomáš","last_name":"Brázdil","full_name":"Brázdil, Tomáš"},{"full_name":"Forejt, Vojtěch","last_name":"Forejt","first_name":"Vojtěch"},{"last_name":"Kučera","full_name":"Kučera, Antonín","first_name":"Antonín"},{"full_name":"Novotny, Petr","last_name":"Novotny","id":"3CC3B868-F248-11E8-B48F-1D18A9856A87","first_name":"Petr"}],"publist_id":"5944","title":"Stability in graphs and games","article_number":"10","project":[{"name":"International IST Postdoc Fellowship Programme","grant_number":"291734","_id":"25681D80-B435-11E9-9278-68D0E5697425","call_identifier":"FP7"}],"has_accepted_license":"1","year":"2016","day":"01","date_published":"2016-08-01T00:00:00Z","doi":"10.4230/LIPIcs.CONCUR.2016.10","date_created":"2018-12-11T11:51:23Z","acknowledgement":"The work has been supported by the Czech Science Foundation, grant No. 15-17564S, by EPSRC grant\r\nEP/M023656/1, and by the People Programme (Marie Curie Actions) of the European Union’s Seventh\r\nFramework Programme (FP7/2007-2013) under REA grant agreement no [291734]","publisher":"Schloss Dagstuhl - Leibniz-Zentrum für Informatik","quality_controlled":"1","oa":1,"date_updated":"2021-01-12T06:49:53Z","ddc":["004"],"department":[{"_id":"KrCh"}],"file_date_updated":"2020-07-14T12:44:44Z","_id":"1325","type":"conference","conference":{"name":"CONCUR: Concurrency Theory","location":"Quebec City, Canada","end_date":"2016-08-26","start_date":"2016-08-23"},"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"status":"public","pubrep_id":"665","publication_status":"published","file":[{"content_type":"application/pdf","relation":"main_file","access_level":"open_access","file_id":"5229","checksum":"3c2dc6ab0358f8aa8f7aa7d6c1293159","file_size":553648,"date_updated":"2020-07-14T12:44:44Z","creator":"system","file_name":"IST-2016-665-v1+1_Forejt_et_al__Stability_in_graphs_and_games.pdf","date_created":"2018-12-12T10:16:40Z"}],"language":[{"iso":"eng"}],"volume":59,"ec_funded":1,"abstract":[{"text":"We study graphs and two-player games in which rewards are assigned to states, and the goal of the players is to satisfy or dissatisfy certain property of the generated outcome, given as a mean payoff property. Since the notion of mean-payoff does not reflect possible fluctuations from the mean-payoff along a run, we propose definitions and algorithms for capturing the stability of the system, and give algorithms for deciding if a given mean payoff and stability objective can be ensured in the system.","lang":"eng"}],"oa_version":"Published Version","scopus_import":1,"alternative_title":["LIPIcs"],"month":"08","intvolume":" 59"},{"user_id":"3E5EF7F0-F248-11E8-B48F-1D18A9856A87","date_updated":"2021-01-12T06:49:53Z","citation":{"ama":"Chatterjee K, Chmelik M. Indefinite-horizon reachability in Goal-DEC-POMDPs. In: Proceedings of the Twenty-Sixth International Conference on International Conference on Automated Planning and Scheduling. Vol 2016-January. AAAI Press; 2016:88-96.","apa":"Chatterjee, K., & Chmelik, M. (2016). Indefinite-horizon reachability in Goal-DEC-POMDPs. In Proceedings of the Twenty-Sixth International Conference on International Conference on Automated Planning and Scheduling (Vol. 2016–January, pp. 88–96). London, United Kingdom: AAAI Press.","ieee":"K. Chatterjee and M. Chmelik, “Indefinite-horizon reachability in Goal-DEC-POMDPs,” in Proceedings of the Twenty-Sixth International Conference on International Conference on Automated Planning and Scheduling, London, United Kingdom, 2016, vol. 2016–January, pp. 88–96.","short":"K. Chatterjee, M. Chmelik, in:, Proceedings of the Twenty-Sixth International Conference on International Conference on Automated Planning and Scheduling, AAAI Press, 2016, pp. 88–96.","mla":"Chatterjee, Krishnendu, and Martin Chmelik. “Indefinite-Horizon Reachability in Goal-DEC-POMDPs.” Proceedings of the Twenty-Sixth International Conference on International Conference on Automated Planning and Scheduling, vol. 2016–January, AAAI Press, 2016, pp. 88–96.","ista":"Chatterjee K, Chmelik M. 2016. Indefinite-horizon reachability in Goal-DEC-POMDPs. Proceedings of the Twenty-Sixth International Conference on International Conference on Automated Planning and Scheduling. ICAPS: International Conference on Automated Planning and Scheduling vol. 2016–January, 88–96.","chicago":"Chatterjee, Krishnendu, and Martin Chmelik. “Indefinite-Horizon Reachability in Goal-DEC-POMDPs.” In Proceedings of the Twenty-Sixth International Conference on International Conference on Automated Planning and Scheduling, 2016–January:88–96. AAAI Press, 2016."},"department":[{"_id":"KrCh"}],"title":"Indefinite-horizon reachability in Goal-DEC-POMDPs","publist_id":"5946","author":[{"first_name":"Krishnendu","id":"2E5DCA20-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-4561-241X","full_name":"Chatterjee, Krishnendu","last_name":"Chatterjee"},{"full_name":"Chmelik, Martin","last_name":"Chmelik","first_name":"Martin","id":"3624234E-F248-11E8-B48F-1D18A9856A87"}],"_id":"1324","project":[{"_id":"2584A770-B435-11E9-9278-68D0E5697425","call_identifier":"FWF","grant_number":"P 23499-N23","name":"Modern Graph Algorithmic Techniques in Formal Verification"},{"name":"Quantitative Graph Games: Theory and Applications","grant_number":"279307","_id":"2581B60A-B435-11E9-9278-68D0E5697425","call_identifier":"FP7"},{"call_identifier":"FWF","_id":"25832EC2-B435-11E9-9278-68D0E5697425","name":"Rigorous Systems Engineering","grant_number":"S 11407_N23"}],"status":"public","conference":{"name":"ICAPS: International Conference on Automated Planning and Scheduling","start_date":"2016-06-12","location":"London, United Kingdom","end_date":"2016-06-17"},"type":"conference","publication":"Proceedings of the Twenty-Sixth International Conference on International Conference on Automated Planning and Scheduling","language":[{"iso":"eng"}],"day":"01","year":"2016","publication_status":"published","ec_funded":1,"date_created":"2018-12-11T11:51:22Z","date_published":"2016-01-01T00:00:00Z","volume":"2016-January","page":"88 - 96","oa_version":"None","abstract":[{"text":"DEC-POMDPs extend POMDPs to a multi-agent setting, where several agents operate in an uncertain environment independently to achieve a joint objective. DEC-POMDPs have been studied with finite-horizon and infinite-horizon discounted-sum objectives, and there exist solvers both for exact and approximate solutions. In this work we consider Goal-DEC-POMDPs, where given a set of target states, the objective is to ensure that the target set is reached with minimal cost. We consider the indefinite-horizon (infinite-horizon with either discounted-sum, or undiscounted-sum, where absorbing goal states have zero-cost) problem. We present a new and novel method to solve the problem that extends methods for finite-horizon DEC-POMDPs and the RTDP-Bel approach for POMDPs. We present experimental results on several examples, and show that our approach presents promising results. Copyright ","lang":"eng"}],"month":"01","main_file_link":[{"url":"http://www.aaai.org/ocs/index.php/ICAPS/ICAPS16/paper/view/12999"}],"publisher":"AAAI Press","scopus_import":1,"quality_controlled":"1"},{"month":"01","scopus_import":1,"quality_controlled":"1","publisher":"ACM","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1602.07565"}],"oa":1,"oa_version":"Preprint","abstract":[{"lang":"eng","text":"We consider partially observable Markov decision processes (POMDPs) with a set of target states and positive integer costs associated with every transition. The traditional optimization objective (stochastic shortest path) asks to minimize the expected total cost until the target set is reached. We extend the traditional framework of POMDPs to model energy consumption, which represents a hard constraint. The energy levels may increase and decrease with transitions, and the hard constraint requires that the energy level must remain positive in all steps till the target is reached. First, we present a novel algorithm for solving POMDPs with energy levels, developing on existing POMDP solvers and using RTDP as its main method. Our second contribution is related to policy representation. For larger POMDP instances the policies computed by existing solvers are too large to be understandable. We present an automated procedure based on machine learning techniques that automatically extracts important decisions of the policy allowing us to compute succinct human readable policies. Finally, we show experimentally that our algorithm performs well and computes succinct policies on a number of POMDP instances from the literature that were naturally enhanced with energy levels. "}],"date_published":"2016-01-01T00:00:00Z","ec_funded":1,"date_created":"2018-12-11T11:51:23Z","page":"1465 - 1466","day":"01","publication":"Proceedings of the 15th International Conference on Autonomous Agents and Multiagent Systems","language":[{"iso":"eng"}],"year":"2016","publication_status":"published","project":[{"grant_number":"P 23499-N23","name":"Modern Graph Algorithmic Techniques in Formal Verification","call_identifier":"FWF","_id":"2584A770-B435-11E9-9278-68D0E5697425"},{"call_identifier":"FWF","_id":"25832EC2-B435-11E9-9278-68D0E5697425","grant_number":"S 11407_N23","name":"Rigorous Systems Engineering"},{"_id":"25681D80-B435-11E9-9278-68D0E5697425","call_identifier":"FP7","grant_number":"291734","name":"International IST Postdoc Fellowship Programme"},{"grant_number":"279307","name":"Quantitative Graph Games: Theory and Applications","_id":"2581B60A-B435-11E9-9278-68D0E5697425","call_identifier":"FP7"}],"status":"public","type":"conference","conference":{"name":"AAMAS: Autonomous Agents & Multiagent Systems","start_date":"2016-05-09","end_date":"2016-05-13","location":"Singapore"},"_id":"1327","title":"Stochastic shortest path with energy constraints in POMDPs","department":[{"_id":"KrCh"}],"publist_id":"5942","author":[{"first_name":"Tomáš","last_name":"Brázdil","full_name":"Brázdil, Tomáš"},{"last_name":"Chatterjee","full_name":"Chatterjee, Krishnendu","orcid":"0000-0002-4561-241X","first_name":"Krishnendu","id":"2E5DCA20-F248-11E8-B48F-1D18A9856A87"},{"id":"3624234E-F248-11E8-B48F-1D18A9856A87","first_name":"Martin","full_name":"Chmelik, Martin","last_name":"Chmelik"},{"full_name":"Gupta, Anchit","last_name":"Gupta","first_name":"Anchit"},{"full_name":"Novotny, Petr","last_name":"Novotny","first_name":"Petr","id":"3CC3B868-F248-11E8-B48F-1D18A9856A87"}],"user_id":"3E5EF7F0-F248-11E8-B48F-1D18A9856A87","date_updated":"2021-01-12T06:49:54Z","citation":{"chicago":"Brázdil, Tomáš, Krishnendu Chatterjee, Martin Chmelik, Anchit Gupta, and Petr Novotný. “Stochastic Shortest Path with Energy Constraints in POMDPs.” In Proceedings of the 15th International Conference on Autonomous Agents and Multiagent Systems, 1465–66. ACM, 2016.","ista":"Brázdil T, Chatterjee K, Chmelik M, Gupta A, Novotný P. 2016. Stochastic shortest path with energy constraints in POMDPs. Proceedings of the 15th International Conference on Autonomous Agents and Multiagent Systems. AAMAS: Autonomous Agents & Multiagent Systems, 1465–1466.","mla":"Brázdil, Tomáš, et al. “Stochastic Shortest Path with Energy Constraints in POMDPs.” Proceedings of the 15th International Conference on Autonomous Agents and Multiagent Systems, ACM, 2016, pp. 1465–66.","ieee":"T. Brázdil, K. Chatterjee, M. Chmelik, A. Gupta, and P. Novotný, “Stochastic shortest path with energy constraints in POMDPs,” in Proceedings of the 15th International Conference on Autonomous Agents and Multiagent Systems, Singapore, 2016, pp. 1465–1466.","short":"T. Brázdil, K. Chatterjee, M. Chmelik, A. Gupta, P. Novotný, in:, Proceedings of the 15th International Conference on Autonomous Agents and Multiagent Systems, ACM, 2016, pp. 1465–1466.","ama":"Brázdil T, Chatterjee K, Chmelik M, Gupta A, Novotný P. Stochastic shortest path with energy constraints in POMDPs. In: Proceedings of the 15th International Conference on Autonomous Agents and Multiagent Systems. ACM; 2016:1465-1466.","apa":"Brázdil, T., Chatterjee, K., Chmelik, M., Gupta, A., & Novotný, P. (2016). Stochastic shortest path with energy constraints in POMDPs. In Proceedings of the 15th International Conference on Autonomous Agents and Multiagent Systems (pp. 1465–1466). Singapore: ACM."}},{"page":"32 - 49","date_published":"2016-09-22T00:00:00Z","doi":"10.1007/978-3-319-46520-3_3","date_created":"2018-12-11T11:51:23Z","year":"2016","day":"22","quality_controlled":"1","publisher":"Springer","oa":1,"acknowledgement":"The research was funded by the Czech Science Foundation Grant No. P202/12/G061 and by the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement no [291734].","publist_id":"5943","author":[{"first_name":"Tomáš","full_name":"Brázdil, Tomáš","last_name":"Brázdil"},{"first_name":"Antonín","last_name":"Kučera","full_name":"Kučera, Antonín"},{"last_name":"Novotny","full_name":"Novotny, Petr","first_name":"Petr","id":"3CC3B868-F248-11E8-B48F-1D18A9856A87"}],"title":"Optimizing the expected mean payoff in Energy Markov Decision Processes","citation":{"ieee":"T. Brázdil, A. Kučera, and P. Novotný, “Optimizing the expected mean payoff in Energy Markov Decision Processes,” presented at the ATVA: Automated Technology for Verification and Analysis, Chiba, Japan, 2016, vol. 9938, pp. 32–49.","short":"T. Brázdil, A. Kučera, P. Novotný, in:, Springer, 2016, pp. 32–49.","ama":"Brázdil T, Kučera A, Novotný P. Optimizing the expected mean payoff in Energy Markov Decision Processes. In: Vol 9938. Springer; 2016:32-49. doi:10.1007/978-3-319-46520-3_3","apa":"Brázdil, T., Kučera, A., & Novotný, P. (2016). Optimizing the expected mean payoff in Energy Markov Decision Processes (Vol. 9938, pp. 32–49). Presented at the ATVA: Automated Technology for Verification and Analysis, Chiba, Japan: Springer. https://doi.org/10.1007/978-3-319-46520-3_3","mla":"Brázdil, Tomáš, et al. Optimizing the Expected Mean Payoff in Energy Markov Decision Processes. Vol. 9938, Springer, 2016, pp. 32–49, doi:10.1007/978-3-319-46520-3_3.","ista":"Brázdil T, Kučera A, Novotný P. 2016. Optimizing the expected mean payoff in Energy Markov Decision Processes. ATVA: Automated Technology for Verification and Analysis, LNCS, vol. 9938, 32–49.","chicago":"Brázdil, Tomáš, Antonín Kučera, and Petr Novotný. “Optimizing the Expected Mean Payoff in Energy Markov Decision Processes,” 9938:32–49. Springer, 2016. https://doi.org/10.1007/978-3-319-46520-3_3."},"user_id":"3E5EF7F0-F248-11E8-B48F-1D18A9856A87","project":[{"call_identifier":"FP7","_id":"25681D80-B435-11E9-9278-68D0E5697425","name":"International IST Postdoc Fellowship Programme","grant_number":"291734"}],"volume":9938,"ec_funded":1,"publication_status":"published","language":[{"iso":"eng"}],"scopus_import":1,"alternative_title":["LNCS"],"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1607.00678"}],"month":"09","intvolume":" 9938","abstract":[{"text":"Energy Markov Decision Processes (EMDPs) are finite-state Markov decision processes where each transition is assigned an integer counter update and a rational payoff. An EMDP configuration is a pair s(n), where s is a control state and n is the current counter value. The configurations are changed by performing transitions in the standard way. We consider the problem of computing a safe strategy (i.e., a strategy that keeps the counter non-negative) which maximizes the expected mean payoff. ","lang":"eng"}],"oa_version":"Preprint","department":[{"_id":"KrCh"}],"date_updated":"2021-01-12T06:49:53Z","type":"conference","conference":{"name":"ATVA: Automated Technology for Verification and Analysis","location":"Chiba, Japan","end_date":"2016-10-20","start_date":"2016-10-17"},"status":"public","_id":"1326"},{"author":[{"first_name":"Manfred","full_name":"Milinski, Manfred","last_name":"Milinski"},{"last_name":"Hilbe","full_name":"Hilbe, Christian","orcid":"0000-0001-5116-955X","first_name":"Christian","id":"2FDF8F3C-F248-11E8-B48F-1D18A9856A87"},{"full_name":"Semmann, Dirk","last_name":"Semmann","first_name":"Dirk"},{"last_name":"Sommerfeld","full_name":"Sommerfeld, Ralf","first_name":"Ralf"},{"first_name":"Jochem","full_name":"Marotzke, Jochem","last_name":"Marotzke"}],"publist_id":"5935","title":"Humans choose representatives who enforce cooperation in social dilemmas through extortion","citation":{"ista":"Milinski M, Hilbe C, Semmann D, Sommerfeld R, Marotzke J. 2016. Humans choose representatives who enforce cooperation in social dilemmas through extortion. Nature Communications. 7, 10915.","chicago":"Milinski, Manfred, Christian Hilbe, Dirk Semmann, Ralf Sommerfeld, and Jochem Marotzke. “Humans Choose Representatives Who Enforce Cooperation in Social Dilemmas through Extortion.” Nature Communications. Nature Publishing Group, 2016. https://doi.org/10.1038/ncomms10915.","apa":"Milinski, M., Hilbe, C., Semmann, D., Sommerfeld, R., & Marotzke, J. (2016). Humans choose representatives who enforce cooperation in social dilemmas through extortion. Nature Communications. Nature Publishing Group. https://doi.org/10.1038/ncomms10915","ama":"Milinski M, Hilbe C, Semmann D, Sommerfeld R, Marotzke J. Humans choose representatives who enforce cooperation in social dilemmas through extortion. Nature Communications. 2016;7. doi:10.1038/ncomms10915","ieee":"M. Milinski, C. Hilbe, D. Semmann, R. Sommerfeld, and J. Marotzke, “Humans choose representatives who enforce cooperation in social dilemmas through extortion,” Nature Communications, vol. 7. Nature Publishing Group, 2016.","short":"M. Milinski, C. Hilbe, D. Semmann, R. Sommerfeld, J. Marotzke, Nature Communications 7 (2016).","mla":"Milinski, Manfred, et al. “Humans Choose Representatives Who Enforce Cooperation in Social Dilemmas through Extortion.” Nature Communications, vol. 7, 10915, Nature Publishing Group, 2016, doi:10.1038/ncomms10915."},"user_id":"3E5EF7F0-F248-11E8-B48F-1D18A9856A87","article_number":"10915","date_created":"2018-12-11T11:51:25Z","doi":"10.1038/ncomms10915","date_published":"2016-03-07T00:00:00Z","year":"2016","has_accepted_license":"1","publication":"Nature Communications","day":"07","oa":1,"quality_controlled":"1","publisher":"Nature Publishing Group","acknowledgement":"We thank the students for participation; H.-J. Krambeck for writing the software for the game; H. Arndt, T. Bakker, L. Becks, H. Brendelberger, S. Dobler and T. Reusch for support; and the Max Planck Society for the Advancement of Science for funding.","department":[{"_id":"KrCh"}],"file_date_updated":"2020-07-14T12:44:44Z","date_updated":"2021-01-12T06:49:57Z","ddc":["519","530","599"],"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"type":"journal_article","pubrep_id":"661","status":"public","_id":"1333","volume":7,"publication_status":"published","language":[{"iso":"eng"}],"file":[{"relation":"main_file","access_level":"open_access","content_type":"application/pdf","file_id":"4834","checksum":"9ea0d7ce59a555a1cb8353d5559407cb","creator":"system","file_size":1432577,"date_updated":"2020-07-14T12:44:44Z","file_name":"IST-2016-661-v1+1_ncomms10915.pdf","date_created":"2018-12-12T10:10:44Z"}],"scopus_import":1,"intvolume":" 7","month":"03","abstract":[{"lang":"eng","text":"Social dilemmas force players to balance between personal and collective gain. In many dilemmas, such as elected governments negotiating climate-change mitigation measures, the decisions are made not by individual players but by their representatives. However, the behaviour of representatives in social dilemmas has not been investigated experimentally. Here inspired by the negotiations for greenhouse-gas emissions reductions, we experimentally study a collective-risk social dilemma that involves representatives deciding on behalf of their fellow group members. Representatives can be re-elected or voted out after each consecutive collective-risk game. Selfish players are preferentially elected and are hence found most frequently in the "representatives" treatment. Across all treatments, we identify the selfish players as extortioners. As predicted by our mathematical model, their steadfast strategies enforce cooperation from fair players who finally compensate almost completely the deficit caused by the extortionate co-players. Everybody gains, but the extortionate representatives and their groups gain the most."}],"oa_version":"Published Version"}]