1,426 research outputs found

    Forecasting audience increase on YouTube

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    User profiles constructed on Social Web platforms are often motivated by the need to maximise user reputation within a community. Subscriber, or follower, counts are an indicator of the influence and standing that the user has, where greater values indicate a greater perception or regard for what the user has to say or share. However, at present there lacks an understanding of the factors that lead to an increase in such audience levels, and how a user’s behaviour can a!ect their reputation. In this paper we attempt to fill this gap, by examining data collected from YouTube over regular time intervals. We explore the correlation between the subscriber counts and several behaviour features - extracted from both the user’s profile and the content they have shared. Through the use of a Multiple Linear Regression model we are able to forecast the audience levels that users will yield based on observed behaviour. Combining such a model with an exhaustive feature selection process, we yield statistically significant performance over a baseline model containing all features

    The OU Linked Open Data: production and consumption

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    The aim of this paper is to introduce the current efforts toward the release and exploitation of The Open University's (OU) Linked Open Data (LOD). We introduce the work that has been done within the LUCERO project in order to select, extract and structure subsets of information contained within the OU data sources and migrate and expose this information as part of the LOD cloud. To show the potential of such exposure we also introduce three different prototypes that exploit this new educational resource: (1) the OU expert search system, a tool focused on fnding the best experts for a certain topic within the OU staff; (2) the Buddy Study system, a tool that relies on Facebook information to identify common interest among friends and recommend potential courses within the OU that `buddies' can study together, and; (3) Linked OpenLearn, an application that enables exploring linked courses, Podcasts and tags to OpenLearn units. Its aim is to enhance the browsing experience for students, by detecting relevant educational resources on fly while reading an OpenLearn unit

    Contextualized Functions: Possible Tensions In Stecker’s Definition

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    Stecker's revised definition of art in Artworks: Definition, Meaning, Value is stated thus: "w is a work of art at t if and only if (a) w has form c which is a member of C and the maker of w intended it to fulfill a sub-set of functions f1 ... fn of F such that f1 ... fn are functions of c or (b) w is an object which achieves excellence in fulfilling a function in F" 1 where: w is an artwork; t is a time; C is the set of central art forms at t; c is a member of the set C; F is the set of functions standardly or correctly regarded as belonging to C at t; f1 ... fn are members of the set F

    Mining user development signals for online community churner detection

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    Churners are users who stop using a given service after previously signing up. In the domain of telecommunications and video games, churners represent a loss of revenue as a user leaving indicates that they will no longer pay for the service. In the context of online community platforms (e.g., community message boards, social networking sites, question--answering systems, etc.), the churning of a user can represent different kinds of loss: of social capital, of expertise, or of a vibrant individual who is a mediator for interaction and communication. Detecting which users are likely to churn from online communities, therefore, enables community managers to offer incentives to entice those users back; as retention is less expensive than re-signing users up. In this article, we tackle the task of detecting churners on four online community platforms by mining user development signals. These signals explain how users have evolved along different dimensions (i.e., social and lexical) relative to their prior behaviour and the community in which they have interacted. We present a linear model, based upon elastic-net regularisation, that uses extracted features from the signals to detect churners. Our evaluation of this model against several state of the art baselines, including our own prior work, empirically demonstrates the superior performance that this approach achieves for several experimental settings. This article presents a novel approach to churn prediction that takes a different route from existing approaches that are based on measuring static social network properties of users (e.g., centrality, in-degree, etc.)

    The foundation for a definition: an analytic analysis of the framework of practice in which art is made

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    The thesis provides an analysis of what any definition of 'art' that hopes to be extensionally adequate must include within its scope. The presumption throughout is that extension of art at any one time is that which is to be explained so that its intension should be discovered from its extension. The analysis proceeds through analysing how agents make artworks and what sorts of entities artworks are, in order to provide a framework within which any proffered definition, or objection to a definitional project, must operate. Thus, the point is not to critically examine the range of definitions already on offer but to set out those features of artistic practice that require inclusion within any definitional project. This project begins through demonstrating the inadequacy of empirical theories, through thought experiments using the method of indiscemibles drawn from the writings of Arthur Danto. This, in a modified form, is used throughout the thesis. There then follows an attempt to discover the most extreme cases with which a definition will need to contend through an investigation into the minimal limits of how artworks can be made and what things can be artworks. The result is that artworks have to be made so that they are identifiable as a distinct entity within a determinate category of art. A new form of'post-empirical minimalism' that will provide classificatory limit for post-empirical definitions in terms of artistic and other relational properties is identified and defended. The thesis closes with a proposal for simple ontology of art, consistent with the framework of making set out in the preceding chapters and which can be applied to many different definitional projects and which places the ontology of even the most avant-garde parts of artistic practice within the same basic categories of artwork ascanonical artworks

    Predatory grasshopper mice

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    Structure and function of sea urchin neuropeptides

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    PhDThe subject of this thesis is the identification and functional characterization of sea urchin neuropeptides. Neuropeptides are important mediators of neural signalling in all known animals with a nervous system, including bilaterians, ctenophorans, and cnidarians. Sea urchin neuropeptides are of particular interest for three significant reasons; echinoderms have a radically different secondarily-derived pentaradial body structure, sea urchins have served as model organisms for research into embryonic development, and thirdly because the genome of a sea urchin, the purple sea urchin Strongylocentrotus purpuratus (Stimpson, 1857) has been sequenced (Sodergren et al., 2006). Only one family of neuropeptides, the SALMFamides, has previously been characterized in all classes of the phylum Echinodermata. The thesis reports the identification of putative neuropeptide GPCRs and at least seven novel sea urchin neuropeptide genes using genomic and Expressed Sequence Tag (EST) analysis. The novel sea urchin neuropeptides identified include putative homologues of vasotocin, the sea cucumber neuropeptide NGIWYamide, thyrotropin-releasing hormone, gonadotropin-releasing hormone, and calcitonin. A further three peptide precursor genes encoding peptides lacking strong homology to any known peptides were also identified and the peptides have been named GKamides and Pedal Peptide-like Neuropeptides. Two of the peptide precursor genes, those encoding peptides homologous to vasotocin and NGIWYamide, also each encode neurophysin domains, which have previously only been identified in association with vasopressin/oxytocin-like peptides. Biochemical and pharmacological techniques were employed to investigate the occurrence and functions of the putative neuropeptides identified. These included mass spectroscopy and in vitro bioassays, the former to detect the putative novel neuropeptides identified in this study and the latter to investigate bioactivity of the peptides in sea urchins. The thesis provides evidence of the neural expression and bioactivity of novel sea urchin neuropeptides and contributes to our understanding of the role of neuropeptides in echinoderm physiology and behaviour.University of London Central Research Fun
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