498 research outputs found

    L’expressivisme moral : une conclusion de la critique darwinienne de Sharon Street ?

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    Un des objectifs de la critique darwinienne de Sharon Street est de montrer que nous devons opter pour l’antiréalisme – plutôt que le réalisme – comme théorie métaéthique appropriée pour décrire le phénomène moral. Plus encore, parmi les théories antiréalistes, Street cherche à défendre que c’est le constructivisme humien que nous devrions privilégier. Dans cet article, je cherche à évaluer la possibilité que l’expressivisme moral soit également une conclusion de la critique darwinienne. Pour ce faire, j’explique en quoi nous pouvons de manière légitime considérer que le constructivisme humien est une théorie expressiviste, dans la mesure où nous nous limitons aux deux thèses que je considère comme étant constitutives de l’expressivisme : l’internalisme motivationnel et la conception humienne des jugements normatifs. C’est de cette manière qu’il est possible de soutenir que l’expressivisme moral est une conclusion de la critique darwinienne

    Le fondhérentisme de Susan Haack : un fondationnalisme faible ?

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    Susan Haack présente dans Evidence and Inquiry une théorie de la justification épistémique qu’elle appelle le fondhérentisme. Elle développe sa théorie dans la perspective d’occuper l’espace logique qu’elle considère disponible entre le fondationnalisme et le cohérentisme. Ainsi, elle vise un « juste milieu » entre les théories traditionnelles en épistémologie analytique en proposant une théorie de la justification à double aspect : causal et évaluatif. Cependant, Peter Tramel, dans une critique du projet de Haack, essaie de démontrer que le fondhérentisme est un fondationnalisme faible. Ces critiques viennent remettre en question la capacité de Haack à réaliser son projet, soit de présenter une théorie qui n’est ni un cohérentisme ni un fondationnalisme. Étant donné qu’il n’y a aucune réponse connue de Haack à la critique de Tramel, je propose de discuter la critique de ce dernier et de défendre le projet fondhérentiste

    Non-Naturalism and the Metaphysics of Normative Properties

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    Normative non-naturalists seem to be committed to a supervenience relation about the normative. This means that the normative necessarily varies with the non-normative, such that the normative features of a person or a thing cannot change if the non-normative features of that person or that thing do not change either. Furthermore, according to normative non-naturalists, normative properties are metaphysically discontinuous with non-normative properties, as the former are irreducible to the latter and cannot be exhaustively understood in terms of the latter. However, it is not clear that normative non-naturalists can explain the necessary connection between the normative and the non-normative they themselves seem to maintain; this is the core of the problem of supervenience. In order to respond to the problem of supervenience, non-naturalists could either try to explain the necessary connection between the normative and the non-normative, or deny that this necessary connection between the normative and the non-normative holds. I first define normative non-naturalists theoretical commitments and give a few reasons to take this view seriously (Chapter 1), and then I explain how the problem of supervenience against non-naturalism should be understood (Chapter 2). Then, I argue that there are issues with the most convincing attempts to explain the necessary connection between the normative and the non-normative (Chapter 3) and with the most convincing attempts to deny this necessary connection (Chapter 4). My conclusion is then that non-naturalists do not have a convincing response to the problem of supervenience

    Automated measurement of Drosophila wings

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    BACKGROUND: Many studies in evolutionary biology and genetics are limited by the rate at which phenotypic information can be acquired. The wings of Drosophila species are a favorable target for automated analysis because of the many interesting questions in evolution and development that can be addressed with them, and because of their simple structure. RESULTS: We have developed an automated image analysis system (WINGMACHINE) that measures the positions of all the veins and the edges of the wing blade of Drosophilid flies. A video image is obtained with the aid of a simple suction device that immobilizes the wing of a live fly. Low-level processing is used to find the major intersections of the veins. High-level processing then optimizes the fit of an a priori B-spline model of wing shape. WINGMACHINE allows the measurement of 1 wing per minute, including handling, imaging, analysis, and data editing. The repeatabilities of 12 vein intersections averaged 86% in a sample of flies of the same species and sex. Comparison of 2400 wings of 25 Drosophilid species shows that wing shape is quite conservative within the group, but that almost all taxa are diagnosably different from one another. Wing shape retains some phylogenetic structure, although some species have shapes very different from closely related species. The WINGMACHINE system facilitates artificial selection experiments on complex aspects of wing shape. We selected on an index which is a function of 14 separate measurements of each wing. After 14 generations, we achieved a 15 S.D. difference between up and down-selected treatments. CONCLUSION: WINGMACHINE enables rapid, highly repeatable measurements of wings in the family Drosophilidae. Our approach to image analysis may be applicable to a variety of biological objects that can be represented as a framework of connected lines

    Incremental and Decremental Maintenance of Planar Width

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    We present an algorithm for maintaining the width of a planar point set dynamically, as points are inserted or deleted. Our algorithm takes time O(kn^epsilon) per update, where k is the amount of change the update causes in the convex hull, n is the number of points in the set, and epsilon is any arbitrarily small constant. For incremental or decremental update sequences, the amortized time per update is O(n^epsilon).Comment: 7 pages; 2 figures. A preliminary version of this paper was presented at the 10th ACM/SIAM Symp. Discrete Algorithms (SODA '99); this is the journal version, and will appear in J. Algorithm

    Evaluation of glare reducing skin coatings as utilized in athletics

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    For many years, athletes have been wearing a black substance under their eyes. The ability of this substance to enhance an athlete\u27s performance has never been tested. This paper will address the ability of this substance to increase contrast sensitivity. Three different glare reducing skin coatings were photometrically tested to determine the product with the lowest gloss index. Utilizing the Arden Plates, contrast sensitivity (CS) was measured on 55 subjects ages 22-40 in a high glare environment both with and without the most effective glare reducing product. When wearing the glare reducing skin coating, subject\u27s CS increased significantly at the spatial frequency of 0.8 cpd, under our test conditions

    Performance Measurements of Supercomputing and Cloud Storage Solutions

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    Increasing amounts of data from varied sources, particularly in the fields of machine learning and graph analytics, are causing storage requirements to grow rapidly. A variety of technologies exist for storing and sharing these data, ranging from parallel file systems used by supercomputers to distributed block storage systems found in clouds. Relatively few comparative measurements exist to inform decisions about which storage systems are best suited for particular tasks. This work provides these measurements for two of the most popular storage technologies: Lustre and Amazon S3. Lustre is an open-source, high performance, parallel file system used by many of the largest supercomputers in the world. Amazon's Simple Storage Service, or S3, is part of the Amazon Web Services offering, and offers a scalable, distributed option to store and retrieve data from anywhere on the Internet. Parallel processing is essential for achieving high performance on modern storage systems. The performance tests used span the gamut of parallel I/O scenarios, ranging from single-client, single-node Amazon S3 and Lustre performance to a large-scale, multi-client test designed to demonstrate the capabilities of a modern storage appliance under heavy load. These results show that, when parallel I/O is used correctly (i.e., many simultaneous read or write processes), full network bandwidth performance is achievable and ranged from 10 gigabits/s over a 10 GigE S3 connection to 0.35 terabits/s using Lustre on a 1200 port 10 GigE switch. These results demonstrate that S3 is well-suited to sharing vast quantities of data over the Internet, while Lustre is well-suited to processing large quantities of data locally.Comment: 5 pages, 4 figures, to appear in IEEE HPEC 201
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