7,885 research outputs found

    Human Perceptions of Fairness in Algorithmic Decision Making: A Case Study of Criminal Risk Prediction

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    As algorithms are increasingly used to make important decisions that affect human lives, ranging from social benefit assignment to predicting risk of criminal recidivism, concerns have been raised about the fairness of algorithmic decision making. Most prior works on algorithmic fairness normatively prescribe how fair decisions ought to be made. In contrast, here, we descriptively survey users for how they perceive and reason about fairness in algorithmic decision making. A key contribution of this work is the framework we propose to understand why people perceive certain features as fair or unfair to be used in algorithms. Our framework identifies eight properties of features, such as relevance, volitionality and reliability, as latent considerations that inform people's moral judgments about the fairness of feature use in decision-making algorithms. We validate our framework through a series of scenario-based surveys with 576 people. We find that, based on a person's assessment of the eight latent properties of a feature in our exemplar scenario, we can accurately (> 85%) predict if the person will judge the use of the feature as fair. Our findings have important implications. At a high-level, we show that people's unfairness concerns are multi-dimensional and argue that future studies need to address unfairness concerns beyond discrimination. At a low-level, we find considerable disagreements in people's fairness judgments. We identify root causes of the disagreements, and note possible pathways to resolve them.Comment: To appear in the Proceedings of the Web Conference (WWW 2018). Code available at https://fate-computing.mpi-sws.org/procedural_fairness

    Analysis of a novel non-contacting waveguide backshort

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    A new non-contacting waveguide backshort has been developed for millimeter and submillimeter wave frequencies. The design consists of a metal bar with rectangular or circular holes cut into it, which is covered with a dielectric (mylar) layer to form a snug fit with the walls of a waveguide. Hole geometries are adjusted to obtain a periodic variation of the guide impedance on the correct length scale, in order to produce efficient reflection of RF power. It is a mechanically rugged design which can be easily fabricated for frequencies from 1 to 1000 GHz and is thus a sound alternative to the miniaturization of conventional non-contacting shorts. To aid in high-frequency design, a rigorous full-wave analysis has been completed, which will allow variations of the size, number and spacing of the holes to be easily analyzed. This paper will review the backshort design and the method developed for theoretical characterization, followed by a comparison of the experimental and numerical results. Low frequency models operating from 4-6 GHz are shown to demonstrate return loss of greater than -0.2 dB over a 33 percent bandwidth. The theory is in good agreement with measured data

    Accurate Realizations of the Ionized Gas in Galaxy Clusters: Calibrating Feedback

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    Using the full, three-dimensional potential of galaxy cluster halos (drawn from an N-body simulation of the current, most favored cosmology), the distribution of the X-ray emitting gas is found by assuming a polytropic equation of state and hydrostatic equilibrium, with constraints from conservation of energy and pressure balance at the cluster boundary. The resulting properties of the gas for these simulated redshift zero clusters (the temperature distribution, mass-temperature and luminosity-temperature relations, and the gas fraction) are compared with observations in the X-ray of nearby clusters. The observed properties are reproduced only under the assumption that substantial energy injection from non-gravitational sources has occurred. Our model does not specify the source, but star formation and AGN may be capable of providing this energy, which amounts to 3 to 5 x10^{-5} of the rest mass in stars (assuming ten percent of the gas initially in the cluster forms stars). With the method described here it is possible to generate realistic X-ray and Sunyaev-Zel'dovich cluster maps and catalogs from N-body simulations, with the distributions of internal halo properties (and their trends with mass, location, and time) taken into account.Comment: Matches ApJ published version; 30 pages, 7 figure

    Experimental observation of oscillating and interacting matter wave dark solitons

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    We report on the generation, subsequent oscillation and interaction of a pair of matter wave dark solitons. These are created by releasing a Bose-Einstein condensate from a double well potential into a harmonic trap in the crossover regime between one dimension (1D) and three dimensions (3D). The oscillation of the solitons is observed and the frequency is in quantitative agreement with simulations using the Gross-Pitaevskii equation. An effective particle picture is developed and reveals that the deviation of the observed frequencies from the asymptotic prediction νz/2\nu_{z}/\sqrt{2}, where νz\nu_{z} is the longitudinal trapping frequency, results from the dimensionality of the system and the interaction between the solitons.Comment: 5 pages, 3 figure

    Arabian Sea mixed layer dynamics experiment : mooring deployment cruise report R/V Thomas Thompson cruise number 46, 14 April-29 April 1995

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    This report describes in a general manner the work that took place during the R/V Thomas Thompson cruise number 46 which was the mooring turnaround cruise for the moored array program. A detailed description of the WHOI surface mooring and its instrumentation is provided. Information about the XBT and CTD data and near-surface temperature data collected during the cruise is also included.Funding was provided by the Office of Naval Research through Grant No. NOOOl4-94-1-0161

    Tony Blair and John Howard: comparative predominance and 'Institution Stretch' in the UK and Australia

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    It has recently been argued that the UK premier enjoys a level of executive power unavailable to US presidents, but how does he or she compare to another prime minister operating within a broadly similar system? Commonalities of intra-executive influence and capacity exist under the premierships in the UK and Australia. Discrete institutional constraints and deviations are evident, but trends and similarities in resource capacity can be clearly identified. These include: the growth of the leaders' office; broadening and centralising of policy advice and media operations; and strengthening of the role and function of ministerial advisers. I contend that this amounts to 'institution stretch', with new structures, processes and practices becoming embedded in the political system by the incumbents. © 2007 The Author. Journal compilation © 2007 Political Studies Association

    Dispersive magnetic excitations in the S=1 antiferromagnet Ba3_3Mn2_2O8_8

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    We present powder inelastic neutron scattering measurements of the S=1 dimerized antiferromagnet Ba3_3Mn2_2O8_8. The T=1.4T=1.4 K magnetic spectrum exhibits a spin-gap of Δ1.0\Delta \approx 1.0 meV and a dispersive spectrum with a bandwidth of approximately 1.5 meV. Comparison to coupled dimer models describe the dispersion and scattering intensity accurately and determine the exchange constants in Ba3_3Mn2_2O8_8. The wave vector dependent scattering intensity confirms the proposed S=1 dimer bond. Temperature dependent measurements of the magnetic excitations indicate the presence of both singlet-triplet and thermally activated triplet-quintet excitations.Comment: 8 pages, 8 figures, Submitted to Physical Review B, Resubmited versio

    Singlet Ground State and Magnetization Plateaus in Ba3_3Mn2_2O8_8

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    Magnetic susceptibility and the magnetization process have been measured in \green polycrystal. In this compound, the magnetic manganese ion exists as Mn5+^{5+} in a tetrahedral environment, and thus the magnetic interaction can be described by an S=1 Heisenberg model. The ground state was found to be a spin singlet with an excitation gap Δ/kB=11.2\Delta/k_{\rm B}=11.2 K. Magnetization plateaus were observed at zero and at half of the saturation magnetization. These results indicate that the present system can be represented by a coupled antiferromagnetic dimer model.Comment: 4 pages, 4 figures, jpsj styl
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