62,756 research outputs found

    Gathering Anonymous, Oblivious Robots on a Grid

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    We consider a swarm of nn autonomous mobile robots, distributed on a 2-dimensional grid. A basic task for such a swarm is the gathering process: All robots have to gather at one (not predefined) place. A common local model for extremely simple robots is the following: The robots do not have a common compass, only have a constant viewing radius, are autonomous and indistinguishable, can move at most a constant distance in each step, cannot communicate, are oblivious and do not have flags or states. The only gathering algorithm under this robot model, with known runtime bounds, needs O(n2)\mathcal{O}(n^2) rounds and works in the Euclidean plane. The underlying time model for the algorithm is the fully synchronous FSYNC\mathcal{FSYNC} model. On the other side, in the case of the 2-dimensional grid, the only known gathering algorithms for the same time and a similar local model additionally require a constant memory, states and "flags" to communicate these states to neighbors in viewing range. They gather in time O(n)\mathcal{O}(n). In this paper we contribute the (to the best of our knowledge) first gathering algorithm on the grid that works under the same simple local model as the above mentioned Euclidean plane strategy, i.e., without memory (oblivious), "flags" and states. We prove its correctness and an O(n2)\mathcal{O}(n^2) time bound in the fully synchronous FSYNC\mathcal{FSYNC} time model. This time bound matches the time bound of the best known algorithm for the Euclidean plane mentioned above. We say gathering is done if all robots are located within a 2×22\times 2 square, because in FSYNC\mathcal{FSYNC} such configurations cannot be solved

    White, Man, and Highly Followed: Gender and Race Inequalities in Twitter

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    Social media is considered a democratic space in which people connect and interact with each other regardless of their gender, race, or any other demographic factor. Despite numerous efforts that explore demographic factors in social media, it is still unclear whether social media perpetuates old inequalities from the offline world. In this paper, we attempt to identify gender and race of Twitter users located in U.S. using advanced image processing algorithms from Face++. Then, we investigate how different demographic groups (i.e. male/female, Asian/Black/White) connect with other. We quantify to what extent one group follow and interact with each other and the extent to which these connections and interactions reflect in inequalities in Twitter. Our analysis shows that users identified as White and male tend to attain higher positions in Twitter, in terms of the number of followers and number of times in user's lists. We hope our effort can stimulate the development of new theories of demographic information in the online space.Comment: In Proceedings of the IEEE/WIC/ACM International Conference on Web Intelligence (WI'17). Leipzig, Germany. August 201

    The politics of in/visibility: carving out queer space in Ul'yanovsk

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    <p>In spite of a growing interest within sexualities studies in the concept of queer space (Oswin 2008), existing literature focuses almost exclusively on its most visible and territorialised forms, such as the gay scene, thus privileging Western metropolitan areas as hubs of queer consumer culture (Binnie 2004). While the literature has emphasised the political significance of queer space as a site of resistance to hegemonic gender and sexual norms, it has again predominantly focused on overt claims to public space embodied in Pride events, neglecting other less open forms of resistance.</p><p> This article contributes new insights to current debates about the construction and meaning of queer space by considering how city space is appropriated by an informal queer network in Ul’ianovsk. The group routinely occupied very public locations meeting and socialising on the street or in mainstream cafĂ©s in central Ul’ianovsk, although claims to these spaces as queer were mostly contingent, precarious or invisible to outsiders. The article considers how provincial location affects tactics used to carve out communal space, foregrounding the importance of local context and collective agency in shaping specific forms of resistance, and questioning ethnocentric assumptions about the empowering potential of visibility.</p&gt

    The enowning of thought and whakapapa: Heidegger's fourfold

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    Throughout colonization, Maori have been constantly urged to think of their terminology, and the objects it relates to, along constrained lines. In this practice, the self and other things are arguably restricted and impoverished. However, certain frequently used Maori terms – such as “whakapapa” and “whakaaro” – may be read alongside Heidegger’s “Ereignis,” revealing a completely other sense to them than their orthodox, respective translations of “genealogy” and “to think” allow. This kind of thinking in concert with an existential philosophy is an active process that allows for the “freeing up” of entities and a colonized group. With Heidegger’s assistance, the terms, and the original sources they refer to, reflect a kind of “Geviert”/Fourfold that ensures a continual strife and interplay between things in the world and self

    Lobbying the European Parliament: a necessary evil. CEPS Policy Brief No. 242, May 2011

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    While the European Parliament is in many ways more transparent and more accessible than many of the EU’s national parliaments, the code of conduct for lobbyists and the Parliament’s own Rules of Procedure are rather vague. As a result of the ‘cash for laws’ scandal, the EP President, Jerzy Buzek, has established a working group to draw up a new set of rules to govern the access and behaviour of lobbyists and to formulate a code of conduct for MEPs

    Conservation gets personal

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