Infinite games with finite knowledge gaps

Infinite games where several players seek to coordinate under imperfect information are deemed to be undecidable, unless the information is hierarchically ordered among the players. We identify a class of games for which joint winning strategies can be constructed effectively without restricting the direction of information flow. Instead, our condition requires that the players attain common knowledge about the actual state of the game over and over again along every play. We show that it is decidable whether a given game satisfies the condition, and prove tight complexity bounds for the strategy synthesis problem under $\omega$-regular winning conditions given by parity automata.Comment: 39 pages; 2nd revision; submitted to Information and Computatio

Survey of the State of the Art in Natural Language Generation: Core tasks, applications and evaluation

This paper surveys the current state of the art in Natural Language Generation (NLG), defined as the task of generating text or speech from non-linguistic input. A survey of NLG is timely in view of the changes that the field has undergone over the past decade or so, especially in relation to new (usually data-driven) methods, as well as new applications of NLG technology. This survey therefore aims to (a) give an up-to-date synthesis of research on the core tasks in NLG and the architectures adopted in which such tasks are organised; (b) highlight a number of relatively recent research topics that have arisen partly as a result of growing synergies between NLG and other areas of artificial intelligence; (c) draw attention to the challenges in NLG evaluation, relating them to similar challenges faced in other areas of Natural Language Processing, with an emphasis on different evaluation methods and the relationships between them.Comment: Published in Journal of AI Research (JAIR), volume 61, pp 75-170. 118 pages, 8 figures, 1 tabl

Thesis

Thesis (MA (Philosophy))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: This thesis consists of two essays, each focussing on a current topic in aesthetics in the tradition of analytic philosophy. First paper (On depiction) Given broad consensus that resemblance theories do not do well at explaining depiction, two alternative approaches have dominated the literature in recent decades: (1) Perceptual accounts try to ground depiction in the phenomenology of our pictorial experiences; (2) Structural accounts understand pictures as symbols in pictorial symbol systems. I follow Dominic Lopes in granting that the two approaches, often interpreted as each other’s rivals, both have merit and are successful in answering divergent questions about depiction. After taking stock of the most influential theories from both approaches, I turn to John Kulvicki’s recent work. He has made surprising progress as a proponent of the structural approach. His attempt to define depiction in structural terms is groundbreaking and, for the most part, successful. The paper measures some of his suggestions on picture structure and perception against the well-established “twofoldness”-thesis of the perceptual theorist on depiction, Richard Wollheim. Wollheim’s theory is defended and suggestions made to adapt Kulvicki’s theory accordingly. Second paper (On expression) Since Frank Sibley’s early papers in the mid-twentieth century, analytic aesthetics has broadened its field of inquiry to extend past the traditional focus on judgements of beauty or aesthetic merit, to peripheral terms, concepts, properties and judgements (e.g. of grace, elegance, garishness, daintiness, dumpiness, etc.). Nick Zangwill gives a traditionalist report of what binds the new, broad and heterogeneous category of the aesthetic together. He argues that purely evaluative aesthetic judgements of beauty or ugliness (i.e. “verdicts”) are fundamental. All other aesthetic judgements derive their evaluative aesthetic nature from them. In this essay it is argued that Zangwill’s defence of beauty’s supremacy in the category of the aesthetic, does not do justice to ostensible instances of non-evaluative judgements that ascribe expressive properties to artworks. Nelson Goodman’s cognitivist theory of expression in art is used as a foil for Zangwill’s claims.AFRIKAANSE OPSOMMING: Hierdie tesis bestaan uit twee essays, elk oor ’n aktuele onderwerp in estetika in die tradisie van die analitiese filosofie. Eerste essay (Oor uitbeelding, oftewel “piktoriale representasie”) Gegewe ’n algemene konsensus dat ooreenkoms-teorieë nie slaag daarin om uitbeelding (“depiction”) te verklaar nie, is daar twee alternatiewe benaderings wat die onlangse literatuur oor die onderwerp oorheers: (1) die perseptuele benadering probeer uitbeelding begrond in die fenomenologie van ons piktoriale ervaringe; (2) die strukturele benadering verstaan beelde as simbole in piktoriale simboolsisteme. In navolging van Dominic Lopes neem ek aan dat dié twee benaderings, wat normaalweg as mekaar se opponente beskou word, altwee meriete dra en onderskeidelik sukses behaal in die beantwoording van heel uiteenlopende vrae oor die aard van uitbeelding. Na ’n bestekopname van die mees invloedryke teorieë onder beide benaderings, word John Kulvicki se onlangse werk oorweeg. Hy maak verrassende vooruitgang as ondersteuner van die strukturele benadering. Sy poging om uitbeelding in strukturele terme te definiëer is revolusionêr en bied stof vir nadenke. In hierdie essay word sommige van sy voorstelle oor beeld-struktuur en -waarneming gemeet aan die gevestigde “twofoldness”-tesis van Richard Wollheim. Wollheim se perseptuele teorie word verdedig en ’n voorstelle word gemaak om Kulvicki se teorie daarvolgens aan te pas. Tweede essay (Oor uitdrukking) Sedert Frank Sibley se vroeë essays in die middel van die twintigste eeu het die analitiese estetika sy visier verbreed om verby die tradisionele fokus op oordele van skoonheid en estetiese waarde te kyk, na perifere terme, begrippe, eienskappe en oordele (van bv. grasie, delikaatheid, balans, strakheid, elegansie, ens., ens.). Nick Zangwill gee ’n tradisionalistiese verslag van wat die nuwe, breë en heterogene kategorie van die estetiese saambind. Hy argumenteer dat suiwer evaluerende oordele van skoonheid fundamenteel bly. Alle ander estetiese oordele se estetiese aard word daarvan afgelei. In hierdie essay argumenteer ek dat Zangwill se verdediging van skoonheid (of estetiese waarde) as fundamenteel tot die kategorie van die estetiese, nie laat reg geskied aan aantoonbare gevalle van nie-evaluerende oordele, naamlik dié wat ekspressiewe eienskappe aan kunswerke toeskryf, nie. Nelson Goodman se kognitiewe teorie van van uitdrukking in kuns word gebruik as teenhanger en wegspringplek vir kritiek op Zangwill se aansprake

Scientific Advice to Public Policy-Making

A feature of policy-making today is its dependence on scientific advice to deliver public policies that are robust, credible, and effective. This paper discusses how policy-making profits from scientific advice in areas where science and technology are significant. Particular attention is given to issues holding a high level of uncertainty, either because of inherent variability, because science is incomplete or controversial, or because data are inadequate to support a definitive answer. First, we analyse the social context that characterises the relationship between science and policy-making, with a focus on the decrease of public confidence in politicians and scientists. Second, we compare three different sets of guidelines on the collection and use of expertise in policy-making (issued by the UK, Canada and the European Commission, respectively) and identify two different approaches to scientific advice in policy-making. Third, based on a set of cross-national and multi-disciplinary case studies, we look at how the relationship between science and policy-making works in practice and propose a set of recommendations towards the establishment of a more robust and effective policy-making process.Scientific advice, Policy-making, Expertise

Education in South Africa : towards a postmodern democracy

Bibliography: leaves 104-112.The requirements of social and educative justice are examined further in the light of John Rawls's conception of justice as 'fairness'. In particular, critical response to his notions of 'the original position', 'veil of ignorance' and 'overlapping consensus' misrepresents the critical and creative capacity that these concepts properly denote and preserve in the interests of participants' 'strong' democratic capacity. The ethical implications of a non-authoritarian relationship between learners and existing discursive formations are then discussed with reference to Philip Wexler's 'textualist' theory of social analysis and education. His advocacy of 'collective symbolic action' is found to be compatible with an uncoercive discourse ethic, oriented to mutual understanding and contextualised hypothesis formation by self-reflective agents. Inferences for education are proposed, in conclusion, emphasising the teachers' role as agent provocateur of the 'liminal imagination' (generating non-formulaic symbolic movement and self-formative struggle by the learners themselves), which qualifies the usual obligation to approved curricular content. Education for a postmodern democracy is sustained by, and sustains, both context-relative knowledge - publicly educed - and an ongoing 'desublimation' of discourse, in the interests of participatory self-critique and renewal

Artificial Collective Intelligence Engineering: a Survey of Concepts and Perspectives

Collectiveness is an important property of many systems--both natural and artificial. By exploiting a large number of individuals, it is often possible to produce effects that go far beyond the capabilities of the smartest individuals, or even to produce intelligent collective behaviour out of not-so-intelligent individuals. Indeed, collective intelligence, namely the capability of a group to act collectively in a seemingly intelligent way, is increasingly often a design goal of engineered computational systems--motivated by recent techno-scientific trends like the Internet of Things, swarm robotics, and crowd computing, just to name a few. For several years, the collective intelligence observed in natural and artificial systems has served as a source of inspiration for engineering ideas, models, and mechanisms. Today, artificial and computational collective intelligence are recognised research topics, spanning various techniques, kinds of target systems, and application domains. However, there is still a lot of fragmentation in the research panorama of the topic within computer science, and the verticality of most communities and contributions makes it difficult to extract the core underlying ideas and frames of reference. The challenge is to identify, place in a common structure, and ultimately connect the different areas and methods addressing intelligent collectives. To address this gap, this paper considers a set of broad scoping questions providing a map of collective intelligence research, mostly by the point of view of computer scientists and engineers. Accordingly, it covers preliminary notions, fundamental concepts, and the main research perspectives, identifying opportunities and challenges for researchers on artificial and computational collective intelligence engineering.Comment: This is the author's final version of the article, accepted for publication in the Artificial Life journal. Data: 34 pages, 2 figure