2,048 research outputs found

    On Determinisation of Good-for-Games Automata

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    International audienceIn this work we study Good-For-Games (GFG) automata over ω-words: non-deterministic automata where the non-determinism can be resolved by a strategy depending only on the prefix of the ω-word read so far. These automata retain some advantages of determinism: they can be composed with games and trees in a sound way, and inclusion LpAq Ě LpBq can be reduced to a parity game over A ˆ B if A is GFG. Therefore, they could be used to some advantage in verification, for instance as solutions to the synthesis problem. The main results of this work answer the question whether parity GFG automata actually present an improvement in terms of state-complexity (the number of states) compared to the deterministic ones. We show that a frontier lies between the Büchi condition, where GFG automata can be determinised with only quadratic blow-up in state-complexity; and the co-Büchi condition, where GFG automata can be exponentially smaller than any deterministic automaton for the same language. We also study the complexity of deciding whether a given automaton is GFG

    Curating the Legacy of Theresa Hak Kyung Cha

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    Between 24 September and 26 October 2013, Bea de Sousa – curator of the Agency gallery, London (renowned, since the 1990s, for supporting and promoting a speculative art of difference) – staged an exhibition at the Korean Cultural Centre, London, which manifested as a research exercise into the work of the late Korean artist Theresa Hak Kyung Cha (1951?1982). The show, subtitled ‘A Portrait in Fragments’ was a response to the Korean Cultural Centre's ‘Curatorial Open Call’ and based on limited access to the artist's archive at the University of Berkeley California. The curator used the opportunity to expand knowledge and awareness of the artist, introducing Cha to new audiences. She also commissioned contemporary artists Ruth Barker, Bada Song, Jefford Horrigan and Su Jin Lee to devise, produce, display and perform new works in response to Cha's oeuvre. A co-incidental screening of works by Cha at London's ICA, hosted by Juliette Desorgues, was contextualised with a public discussion between Bea de Sousa, the author, and the audience. At the same time the author began to teach a new, BAFA seminar, ‘Technologies of Romance’, at Central St Martins College, London. This article is a response to these combined experiences
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