{"day":"01","issue":"5","month":"08","publication":"Journal of Computer and System Sciences","oa_version":"Published Version","publisher":"Elsevier","quality_controlled":"1","acknowledgement":"This work was partially supported in part by the NSF grants CCR-0132780, CNS-0720884, CCR-0225610, by the Swiss National Science Foundation, ERC Start Grant Graph Games (Project No. 279307), FWF NFN Grant S11407-N23 (RiSE), and a Microsoft faculty fellows","language":[{"iso":"eng"}],"title":"Strategy improvement for concurrent reachability and turn based stochastic safety games","publist_id":"3938","date_published":"2013-08-01T00:00:00Z","pubrep_id":"388","date_created":"2018-12-11T11:59:57Z","abstract":[{"lang":"eng","text":"We consider concurrent games played on graphs. At every round of a game, each player simultaneously and independently selects a move; the moves jointly determine the transition to a successor state. Two basic objectives are the safety objective to stay forever in a given set of states, and its dual, the reachability objective to reach a given set of states. First, we present a simple proof of the fact that in concurrent reachability games, for all ε&gt;0, memoryless ε-optimal strategies exist. A memoryless strategy is independent of the history of plays, and an ε-optimal strategy achieves the objective with probability within ε of the value of the game. In contrast to previous proofs of this fact, our proof is more elementary and more combinatorial. Second, we present a strategy-improvement (a.k.a. policy-iteration) algorithm for concurrent games with reachability objectives. Finally, we present a strategy-improvement algorithm for turn-based stochastic games (where each player selects moves in turns) with safety objectives. Our algorithms yield sequences of player-1 strategies which ensure probabilities of winning that converge monotonically (from below) to the value of the game. © 2012 Elsevier Inc."}],"doi":"10.1016/j.jcss.2012.12.001","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"},"year":"2013","project":[{"_id":"2581B60A-B435-11E9-9278-68D0E5697425","grant_number":"279307","call_identifier":"FP7","name":"Quantitative Graph Games: Theory and Applications"},{"_id":"25863FF4-B435-11E9-9278-68D0E5697425","call_identifier":"FWF","grant_number":"S11407","name":"Game Theory"},{"name":"Microsoft Research Faculty Fellowship","_id":"2587B514-B435-11E9-9278-68D0E5697425"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","department":[{"_id":"KrCh"},{"_id":"ToHe"}],"intvolume":"        79","volume":79,"oa":1,"citation":{"chicago":"Chatterjee, Krishnendu, Luca De Alfaro, and Thomas A Henzinger. “Strategy Improvement for Concurrent Reachability and Turn Based Stochastic Safety Games.” <i>Journal of Computer and System Sciences</i>. Elsevier, 2013. <a href=\"https://doi.org/10.1016/j.jcss.2012.12.001\">https://doi.org/10.1016/j.jcss.2012.12.001</a>.","ama":"Chatterjee K, De Alfaro L, Henzinger TA. Strategy improvement for concurrent reachability and turn based stochastic safety games. <i>Journal of Computer and System Sciences</i>. 2013;79(5):640-657. doi:<a href=\"https://doi.org/10.1016/j.jcss.2012.12.001\">10.1016/j.jcss.2012.12.001</a>","ieee":"K. Chatterjee, L. De Alfaro, and T. A. Henzinger, “Strategy improvement for concurrent reachability and turn based stochastic safety games,” <i>Journal of Computer and System Sciences</i>, vol. 79, no. 5. Elsevier, pp. 640–657, 2013.","apa":"Chatterjee, K., De Alfaro, L., &#38; Henzinger, T. A. (2013). Strategy improvement for concurrent reachability and turn based stochastic safety games. <i>Journal of Computer and System Sciences</i>. Elsevier. <a href=\"https://doi.org/10.1016/j.jcss.2012.12.001\">https://doi.org/10.1016/j.jcss.2012.12.001</a>","ista":"Chatterjee K, De Alfaro L, Henzinger TA. 2013. Strategy improvement for concurrent reachability and turn based stochastic safety games. Journal of Computer and System Sciences. 79(5), 640–657.","short":"K. Chatterjee, L. De Alfaro, T.A. Henzinger, Journal of Computer and System Sciences 79 (2013) 640–657.","mla":"Chatterjee, Krishnendu, et al. “Strategy Improvement for Concurrent Reachability and Turn Based Stochastic Safety Games.” <i>Journal of Computer and System Sciences</i>, vol. 79, no. 5, Elsevier, 2013, pp. 640–57, doi:<a href=\"https://doi.org/10.1016/j.jcss.2012.12.001\">10.1016/j.jcss.2012.12.001</a>."},"_id":"2854","date_updated":"2021-01-12T07:00:16Z","scopus_import":1,"type":"journal_article","file":[{"checksum":"6d3ee12cceb946a0abe69594b6a22409","creator":"system","content_type":"application/pdf","file_size":425488,"date_created":"2018-12-12T10:18:48Z","relation":"main_file","date_updated":"2020-07-14T12:45:51Z","access_level":"open_access","file_name":"IST-2015-388-v1+1_1-s2.0-S0022000012001778-main.pdf","file_id":"5370"}],"file_date_updated":"2020-07-14T12:45:51Z","article_type":"original","article_processing_charge":"No","ddc":["000"],"author":[{"full_name":"Chatterjee, Krishnendu","orcid":"0000-0002-4561-241X","id":"2E5DCA20-F248-11E8-B48F-1D18A9856A87","first_name":"Krishnendu","last_name":"Chatterjee"},{"full_name":"De Alfaro, Luca","last_name":"De Alfaro","first_name":"Luca"},{"orcid":"0000−0002−2985−7724","full_name":"Henzinger, Thomas A","first_name":"Thomas A","last_name":"Henzinger","id":"40876CD8-F248-11E8-B48F-1D18A9856A87"}],"publication_status":"published","status":"public","page":"640 - 657","ec_funded":1,"has_accepted_license":"1"}