3,406 research outputs found

    Automatically assembling a full census of an academic field

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    The composition of the scientific workforce shapes the direction of scientific research, directly through the selection of questions to investigate, and indirectly through its influence on the training of future scientists. In most fields, however, complete census information is difficult to obtain, complicating efforts to study workforce dynamics and the effects of policy. This is particularly true in computer science, which lacks a single, all-encompassing directory or professional organization. A full census of computer science would serve many purposes, not the least of which is a better understanding of the trends and causes of unequal representation in computing. Previous academic census efforts have relied on narrow or biased samples, or on professional society membership rolls. A full census can be constructed directly from online departmental faculty directories, but doing so by hand is prohibitively expensive and time-consuming. Here, we introduce a topical web crawler for automating the collection of faculty information from web-based department rosters, and demonstrate the resulting system on the 205 PhD-granting computer science departments in the U.S. and Canada. This method constructs a complete census of the field within a few minutes, and achieves over 99% precision and recall. We conclude by comparing the resulting 2017 census to a hand-curated 2011 census to quantify turnover and retention in computer science, in general and for female faculty in particular, demonstrating the types of analysis made possible by automated census construction.Comment: 11 pages, 6 figures, 2 table

    Localised AdS5ƗS5\bf{AdS_5\times S^5} Black Holes

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    We numerically construct asymptotically global AdS5ƗS5\mathrm{AdS}_5\times \mathrm{S}^5 black holes that are localised on the S5\mathrm{S}^5. These are solutions to type IIB supergravity with S8\mathrm S^8 horizon topology that dominate the theory in the microcanonical ensemble at small energies. At higher energies, there is a first-order phase transition to AdS5\mathrm{AdS}_5-SchwarzschildƗS5\times \mathrm{S}^5. By the AdS/CFT correspondence, this transition is dual to spontaneously breaking the SO(6)SO(6) R-symmetry of N=4\mathcal N=4 super Yang-Mills down to SO(5)SO(5). We extrapolate the location of this phase transition and compute the expectation value of the resulting scalar operators in the low energy phase.Comment: 11 pages, 6 figure

    Lumpy AdS5Ɨ\bf{_5\times} S5\bf{^5} Black Holes and Black Belts

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    Sufficiently small Schwarzschild black holes in global AdS5Ɨ_5\timesS5^5 are Gregory-Laflamme unstable. We construct new families of black hole solutions that bifurcate from the onset of this instability and break the full SO(6)(6) symmetry group of the S5^5 down to SO(5)(5). These new "lumpy" solutions are labelled by the harmonics ā„“\ell. We find evidence that the ā„“=1\ell = 1 branch never dominates the microcanonical/canonical ensembles and connects through a topology-changing merger to a localised black hole solution with S8^8 topology. We argue that these S8^8 black holes should become the dominant phase in the microcanonical ensemble for small enough energies, and that the transition to Schwarzschild black holes is first order. Furthermore, we find two branches of solutions with ā„“=2\ell = 2. We expect one of these branches to connect to a solution containing two localised black holes, while the other branch connects to a black hole solution with horizon topology S4ƗS4\mathrm S^4\times\mathrm S^4 which we call a "black belt".Comment: 20 pages (plus 17 pages for Appendix on Kaluza-Klein Holography), 14 figure

    Viewpoints: A high-performance high-dimensional exploratory data analysis tool

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    Scientific data sets continue to increase in both size and complexity. In the past, dedicated graphics systems at supercomputing centers were required to visualize large data sets, but as the price of commodity graphics hardware has dropped and its capability has increased, it is now possible, in principle, to view large complex data sets on a single workstation. To do this in practice, an investigator will need software that is written to take advantage of the relevant graphics hardware. The Viewpoints visualization package described herein is an example of such software. Viewpoints is an interactive tool for exploratory visual analysis of large, high-dimensional (multivariate) data. It leverages the capabilities of modern graphics boards (GPUs) to run on a single workstation or laptop. Viewpoints is minimalist: it attempts to do a small set of useful things very well (or at least very quickly) in comparison with similar packages today. Its basic feature set includes linked scatter plots with brushing, dynamic histograms, normalization and outlier detection/removal. Viewpoints was originally designed for astrophysicists, but it has since been used in a variety of fields that range from astronomy, quantum chemistry, fluid dynamics, machine learning, bioinformatics, and finance to information technology server log mining. In this article, we describe the Viewpoints package and show examples of its usage.Comment: 18 pages, 3 figures, PASP in press, this version corresponds more closely to that to be publishe

    Depressed mood in a theological perspective

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    The symptoms of depression and those of accidie as described by the Desert Fathers overlap, in that feelings of despair, guilt, poor estimates of self-worth, lack of energy and self-absorption predominate. Tillich adds to these symptoms a sense of meaninglessness and purposelessness. A new model of depressed mood is proposed which incorporates a variety of different aetiological factors, integrating those from the body and the mind which are found in clinical practice, with others which have a spiritual origin. The need for reconciliation with God, the world and the self means that discernment of spiritual problems can be fundamental in finding an answer to disturbed mood. The psychological aspects of guilt and self-hatred and lethargy are explored through the work of Karen Homey, mainly in a discussion of the compulsions caused by an inflated ego-ideal. The work of Carl Jung emphasises the integration of the shadow, stressing the importance of reconciling polarities in the psyche so as to generate a creative tension which can replenish spiritual and mental energy. Many theologians, including Tillich, also emphasise that opposites must come together, so that God can be found at the centre of all things. Hans Urs von Balthasar is " outstanding because of his understanding of Christ's kenosis in balance with His plerosis These polarities point to the way in which Christ, through His Passion and Resurrection redeems us from godforsakermess, and also suggest a helpful way of understanding the Trinity as Love. Nicholas de Cusa and Ignatius of Loyola, from the fifteenth and sixteenth centuries, have a common strand of finding God in the midst of opposite and fragmenting influences. Miguel de Unamuno at the beginning of this century adds a dimension of God's involvement in tragedy and suffering, and Charles Williams stresses our co-inherence vyith God, and the need for forgiveness in bearing each otherā€™s burdens. The convergence of psychological and theological insights concerning polarities is applied to a recovery model for depressed mood through cognitive therapy, art, and prayer - methods which search, respectively, for truth, beauty and goodness. The process of healing is part of redemption, in that the 'Fruits of the Spirit' are the antithesis of some of the symptoms of depression, such as guilt, anger, self-absorption and fear. We may feel helpless and vulnerable because of negative feelings, but in His total self-giving, Christ suffered the helplessness and agony of the Passion in order to transform our disorders and bring us to His Kingdom of service and praise

    MTF Analysis of an Emulsion Used for Color Paper

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    This thesis studied the relationship between the MTF\u27s of a color emulsion used for photographic paper but coated on clear base. Analysis of the MTF curves show differences that can be attributed to interimage effects. The effects in the red and blue sensitive layers caused a decrease in the overall MTF of the film

    Prestige drives epistemic inequality in the diffusion of scientific ideas

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    The spread of ideas in the scientific community is often viewed as a competition, in which good ideas spread further because of greater intrinsic fitness, and publication venue and citation counts correlate with importance and impact. However, relatively little is known about how structural factors influence the spread of ideas, and specifically how where an idea originates might influence how it spreads. Here, we investigate the role of faculty hiring networks, which embody the set of researcher transitions from doctoral to faculty institutions, in shaping the spread of ideas in computer science, and the importance of where in the network an idea originates. We consider comprehensive data on the hiring events of 5032 faculty at all 205 Ph.D.-granting departments of computer science in the U.S. and Canada, and on the timing and titles of 200,476 associated publications. Analyzing five popular research topics, we show empirically that faculty hiring can and does facilitate the spread of ideas in science. Having established such a mechanism, we then analyze its potential consequences using epidemic models to simulate the generic spread of research ideas and quantify the impact of where an idea originates on its longterm diffusion across the network. We find that research from prestigious institutions spreads more quickly and completely than work of similar quality originating from less prestigious institutions. Our analyses establish the theoretical trade-offs between university prestige and the quality of ideas necessary for efficient circulation. Our results establish faculty hiring as an underlying mechanism that drives the persistent epistemic advantage observed for elite institutions, and provide a theoretical lower bound for the impact of structural inequality in shaping the spread of ideas in science.Comment: 10 pages, 8 figures, 1 tabl
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