A Comparative Study of Ranking-based Semantics for Abstract Argumentation

Argumentation is a process of evaluating and comparing a set of arguments. A way to compare them consists in using a ranking-based semantics which rank-order arguments from the most to the least acceptable ones. Recently, a number of such semantics have been proposed independently, often associated with some desirable properties. However, there is no comparative study which takes a broader perspective. This is what we propose in this work. We provide a general comparison of all these semantics with respect to the proposed properties. That allows to underline the differences of behavior between the existing semantics.Comment: Proceedings of the 30th AAAI Conference on Artificial Intelligence (AAAI-2016), Feb 2016, Phoenix, United State

Identity in Protest: The Market Photo Workshop and the New Generation of South African Photographers

My research analyses the ways in which notions of ‘identity’, ‘memory’ and ‘freedom’ are addressed by a generation of photographers from the Market Photo Workshop in Johannesburg, who grew up just before or after the end of apartheid. The Market Photo Workshop was founded in 1989 by David Goldblatt and has photographically reflected upon South African political struggles and socio-cultural changes since the date of its creation. I consider Lebohang Kganye’s series Her-story/Heir-story (2012-2013), Sipho Gongxeka’s Skeem’ Saka (2013-2014), Matt Kay’s The Front (2014-2015) and Phumzile Khanyile’s Plastic Crowns (2015-2016) as contemporary responses to the Market Photo Workshop’s legacy, particularly with its association to documentary. Each series is the result of a year-long mentorship between a MPW student and an established photographer, providing the opportunity to address how the aesthetic values advocated by an older generation are engaged and possibly transgressed by young students. In the work of Kganye, Gongxeka, Kay and Khanyile, I argue, a re-evaluation of documentary photography parallels a critical examination of the ways in which the history of apartheid has been photographed and remembered. I will demonstrate how, by jostling past models of resistance against conflicting realities in the present, these photographic series take part in the socalled ‘born free’ discussion, which questions the assumption that the post-1994 generation is ‘free’ of the legacy of apartheid