3,140 research outputs found

    Attractive or Aggressive? A Face Recognition and Machine Learning Approach for Estimating Returns to Visual Appearance

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    A growing literature documents the presence of appearance premia in labor markets. We analyze appearance premia in a high-profile, high-pay setting: head football coaches at bigtime college sports programs. These employees face job tasks involving repeated interpersonal interaction on multiple fronts and also act as the “face” of their program. We estimate the attractiveness of each employee using a neural network approach, a pre-trained Convolutional Neural Network fine tuned for this application. This approach can eliminate biases induced by volunteer evaluators and limited numbers of photos. We also use this approach to estimate the perceived aggressiveness of each employee based on observable facial features. Aggressiveness can be detected from facial characteristics and may be a trait preferred by managers and customers in this market. Results show clear evidence of a salary premium for less attractive employees. No beauty premium exists in this market. We also find evidence of an aggressiveness premium, as well as evidence of higher attendance at games coached by less attractive and more aggressive appearing coaches, supporting customer based preferences for the premia. We also provide a methodological contribution by incorporating face recognition and computer vision analysis to evaluate employee appearance

    On E-functions of Semisimple Lie Groups

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    We develop and describe continuous and discrete transforms of class functions on a compact semisimple, but not simple, Lie group GG as their expansions into series of special functions that are invariant under the action of the even subgroup of the Weyl group of GG. We distinguish two cases of even Weyl groups -- one is the direct product of even Weyl groups of simple components of GG, the second is the full even Weyl group of GG. The problem is rather simple in two dimensions. It is much richer in dimensions greater than two -- we describe in detail EE-transforms of semisimple Lie groups of rank 3.Comment: 17 pages, 2 figure

    Control of threshold voltage in E-mode and D-mode GaN-on-Si metal-insulator-semiconductor heterostructure field effect transistors by in-situ fluorine doping of atomic layer deposition Al2O3 gate dielectrics

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    We report the modification and control of threshold voltage in enhancement and depletion mode AlGaN/GaN metal-insulator-semiconductor heterostructure field effect transistors through the use of in-situ fluorine doping of atomic layer deposition Al2O3. Uniform distribution of F ions throughout the oxide thickness are achievable, with a doping level of up to 5.5 × 1019 cm−3 as quantified by secondary ion mass spectrometry. This fluorine doping level reduces capacitive hysteretic effects when exploited in GaN metal-oxide-semiconductor capacitors. The fluorine doping and forming gas anneal also induces an average positive threshold voltage shift of between 0.75 and 1.36 V in both enhancement mode and depletion mode GaN-based transistors compared with the undoped gate oxide via a reduction of positive fixed charge in the gate oxide from +4.67 × 1012 cm−2 to −6.60 × 1012 cm−2. The application of this process in GaN based power transistors advances the realisation of normally off, high power, high speed devices

    Considering the impact of situation-specific motivations and constraints in the design of naturally ventilated and hybrid buildings

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    A simple logical model of the interaction between a building and its occupants is presented based on the principle that if free to do so, people will adjust their posture, clothing or available building controls (windows, blinds, doors, fans, and thermostats) with the aim of achieving or restoring comfort and reducing discomfort. These adjustments are related to building design in two ways: first the freedom to adjust depends on the availability and ease-of-use of control options; second the use of controls affects building comfort and energy performance. Hence it is essential that these interactions are considered in the design process. The model captures occupant use of controls in response to thermal stimuli (too warm, too cold etc.) and non-thermal stimuli (e.g. desire for fresh air). The situation-specific motivations and constraints on control use are represented through trigger temperatures at which control actions occur, motivations are included as negative constraints and incorporated into a single constraint value describing the specifics of each situation. The values of constraints are quantified for a range of existing buildings in Europe and Pakistan. The integration of the model within a design flow is proposed and the impact of different levels of constraints demonstrated. It is proposed that to minimise energy use and maximise comfort in naturally ventilated and hybrid buildings the designer should take the following steps: 1. Provide unconstrained low energy adaptive control options where possible, 2. Avoid problems with indoor air quality which provide motivations for excessive ventilation rates, 3. Incorporate situation-specific adaptive behaviour of occupants in design simulations, 4. Analyse the robustness of designs against variations in patterns of use and climate, and 5. Incorporate appropriate comfort standards into the operational building controls (e.g. BEMS)

    Matching Spherical Dust Solutions to Construct Cosmological Models

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    Conditions for smooth cosmological models are set out and applied to inhomogeneous spherically symmetric models constructed by matching together different Lemaitre-Tolman-Bondi solutions to the Einstein field equations. As an illustration the methods are applied to a collapsing dust sphere in a curved background. This describes a region which expands and then collapses to form a black hole in an Einstein de Sitter background. We show that in all such models if there is no vacuum region then the singularity must go on accreting matter for an infinite LTB time.Comment: 13 pages, Revtex; to appear Gen. Rel. Gra

    Fundamental Weights, Permutation Weights and Weyl Character Formula

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    For a finite Lie algebra GNG_N of rank N, the Weyl orbits W(Λ++)W(\Lambda^{++}) of strictly dominant weights Λ++\Lambda^{++} contain dimW(GN)dimW(G_N) number of weights where dimW(GN)dimW(G_N) is the dimension of its Weyl group W(GN)W(G_N). For any W(Λ++)W(\Lambda^{++}), there is a very peculiar subset (Λ++)\wp(\Lambda^{++}) for which we always have dim(Λ++)=dimW(GN)/dimW(AN1). dim\wp(\Lambda^{++})=dimW(G_N)/dimW(A_{N-1}) . For any dominant weight Λ+ \Lambda^+ , the elements of (Λ+)\wp(\Lambda^+) are called {\bf Permutation Weights}. It is shown that there is a one-to-one correspondence between elements of (Λ++)\wp(\Lambda^{++}) and (ρ)\wp(\rho) where ρ\rho is the Weyl vector of GNG_N. The concept of signature factor which enters in Weyl character formula can be relaxed in such a way that signatures are preserved under this one-to-one correspondence in the sense that corresponding permutation weights have the same signature. Once the permutation weights and their signatures are specified for a dominant Λ+\Lambda^+, calculation of the character ChR(Λ+)ChR(\Lambda^+) for irreducible representation R(Λ+)R(\Lambda^+) will then be provided by ANA_N multiplicity rules governing generalized Schur functions. The main idea is again to express everything in terms of the so-called {\bf Fundamental Weights} with which we obtain a quite relevant specialization in applications of Weyl character formula.Comment: 6 pages, no figures, TeX, as will appear in Journal of Physics A:Mathematical and Genera

    Gender violence in schools: taking the ‘girls-as-victims’ discourse forward

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    This paper draws attention to the gendered nature of violence in schools. Recent recognition that schools can be violent places has tended to ignore the fact that many such acts originate in unequal and antagonistic gender relations, which are tolerated and ‘normalised’ by everyday school structures and processes. After examining some key concepts and definitions, we provide a brief overview of the scope and various manifestations of gender violence in schools, noting that most research to date has focused on girls as victims of gender violence within a heterosexual context and ignores other forms such as homophobic and girl violence. We then move on to look at a few interventions designed to address gender violence in schools in the developing world and end by highlighting the need for more research and improved understanding of the problem and how it can be addressed
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