1,179 research outputs found

    Comparing Line and HR Executives’ Perceptions of HR Effectiveness: Services, Roles, and Contributions

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    This study compared HR and line executives’ evaluations of the effectiveness of the HR function in terms of its service delivery, roles, and contributions to the firm. Survey responses from 44 HR and 59 line executives from 14 companies indicated that (a) HR executives consistently rated the functions effectiveness higher than did line executives, and (b) the greatest differences were observed on the more important and/or strategic aspects of HR. Implications are discussed

    The electronic Hamiltonian for cuprates

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    A realistic many-body Hamiltonian for the cuprate superconductors should include both copper d and oxygen p states, hopping matrix elements between them, and Coulomb energies, both on-site and inter-site. We have developed a novel computational scheme for deriving the relevant parameters ab initio from a constrained occupation local density functional. The scheme includes numerical calculation of appropriate Wannier functions for the copper and oxygen states. Explicit parameter values are given for La2CuO4. These parameters are generally consistent with other estimates and with the observed superexchange energy. Secondly, we address whether this complicated multi-band Hamiltonian can be reduced to a simpler one with fewer basis states per unit cell. We propose a mapping onto a new two-band effective Hamiltonian with one copper d and one oxygen p derived state per unit cell. This mapping takes into account the large oxygen-oxygen hopping given by the ab initio calculations

    Measurement Error in Research on Human Resource Decisions and Firm Performance: How Much Error is There and How Does its Influence Effect Size Estimates?

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    Recent empirical research finds that the relationship between human resource (HR) decisions and firm performance is significant in both statistical and practical terms. However, the typical research design in this area relies upon on a single respondent to validly assess firmwide HR practices. To date, no study has adequately addressed the reliability of such measures, a basic requirement of construct validity. Previous efforts have either defined reliability so narrowly as to miss a major source of measurement error (raters) or have estimated the unreliability due to raters using incorrect methods. In both cases, the result is upwardly biased estimates of reliability. We estimate reliabilities using intraclass correlation and generalizability coefficients. Our reliability estimates suggest substantial measurement error in the types of HR effectiveness and HR practice measures typically used to predict firm performance. We discuss how this degree of measurement influences research and policy implications

    The agrin gene codes for a family of basal lamina proteins that differ in function and distribution

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    We isolated two cDNAs that encode isoforms of agrin, the basal lamina protein that mediates the motor neuron-induced aggregation of acetylcholine receptors on muscle fibers at the neuromuscular junction. Both proteins are the result of alternative splicing of the product of the agrin gene, but, unlike agrin, they are inactive in standard acetylcholine receptor aggregation assays. They lack one (agrin-related protein 1) or two (agrin-related protein 2) regions in agrin that are required for its activity. Expression studies provide evidence that both proteins are present in the nervous system and muscle and that, in muscle, myofibers and Schwann cells synthesize the agrin-related proteins while the axon terminals of motor neurons are the sole source of agrin

    Revisiting the Core Ontology and Problem in Requirements Engineering

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    In their seminal paper in the ACM Transactions on Software Engineering and Methodology, Zave and Jackson established a core ontology for Requirements Engineering (RE) and used it to formulate the "requirements problem", thereby defining what it means to successfully complete RE. Given that stakeholders of the system-to-be communicate the information needed to perform RE, we show that Zave and Jackson's ontology is incomplete. It does not cover all types of basic concerns that the stakeholders communicate. These include beliefs, desires, intentions, and attitudes. In response, we propose a core ontology that covers these concerns and is grounded in sound conceptual foundations resting on a foundational ontology. The new core ontology for RE leads to a new formulation of the requirements problem that extends Zave and Jackson's formulation. We thereby establish new standards for what minimum information should be represented in RE languages and new criteria for determining whether RE has been successfully completed.Comment: Appears in the proceedings of the 16th IEEE International Requirements Engineering Conference, 2008 (RE'08). Best paper awar

    The Computational Power of Optimization in Online Learning

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    We consider the fundamental problem of prediction with expert advice where the experts are "optimizable": there is a black-box optimization oracle that can be used to compute, in constant time, the leading expert in retrospect at any point in time. In this setting, we give a novel online algorithm that attains vanishing regret with respect to NN experts in total O~(N)\widetilde{O}(\sqrt{N}) computation time. We also give a lower bound showing that this running time cannot be improved (up to log factors) in the oracle model, thereby exhibiting a quadratic speedup as compared to the standard, oracle-free setting where the required time for vanishing regret is Θ~(N)\widetilde{\Theta}(N). These results demonstrate an exponential gap between the power of optimization in online learning and its power in statistical learning: in the latter, an optimization oracle---i.e., an efficient empirical risk minimizer---allows to learn a finite hypothesis class of size NN in time O(logN)O(\log{N}). We also study the implications of our results to learning in repeated zero-sum games, in a setting where the players have access to oracles that compute, in constant time, their best-response to any mixed strategy of their opponent. We show that the runtime required for approximating the minimax value of the game in this setting is Θ~(N)\widetilde{\Theta}(\sqrt{N}), yielding again a quadratic improvement upon the oracle-free setting, where Θ~(N)\widetilde{\Theta}(N) is known to be tight

    Nature with a Human Touch: Human-Induced Alteration Negatively Impacts Perceived Naturalness and Preferences for Natural Environments

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    Natural environments vary in the degree to which humans have altered them; some environments, like wilderness areas, are relatively untouched, while others, like urban green spaces, are heavily manicured. The current research examined the effect of human-induced alteration to natural environments on perceived naturalness and environmental preferences in a student sample (Study 1) and a sample of nonstudent adults (Study 2). It was predicted that a human-altered natural environment would be viewed as less natural than a non-altered natural environment. It was also predicted that a human-altered natural environment would be viewed more negatively than a non-altered natural environment. Results largely supported these predictions. Human-altered natural environments were viewed as less natural than non-altered natural environments, and across several indicators of environmental preference, participants responded more negatively to human-altered natural environments than non-altered natural environments. Perceived naturalness mediated the effect of human-induced alteration on each environmental preference variable, suggesting that non-altered environments are preferred because they are viewed as more natural than their human-altered counterparts. These findings are consistent with an evolutionary account of non-altered natural environments offering more benefits and entailing fewer costs than human-altered natural environments. (PsycINFO Database Record (c) 2016 APA, all rights reserved) (journal abstract

    Nature Connectedness Moderates the Effect of Nature Exposure on Explicit and Implicit Measures of Emotion

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    Previous research indicates that both short-term and long-term exposure to natural environments is associated with higher levels of emotional well-being. However, less research has examined whether person-related factors may impact the salutogenic effects of nature. In the current study, we examined whether trait-level nature connectedness moderates the effect of exposure to nature on explicit and implicit measures of affect. Participants (n = 89) completed baseline measurements of trait nature connectedness and affective state. Approximately two weeks later, participants viewed a lab-based immersive simulation of either a natural or built environment and then again completed measures of affective state. Findings indicated that trait nature connectedness moderated the effect of nature on affect, with more positive outcomes of nature exposure observed among those high in nature connectedness. These findings suggest that interacting with nature may be especially beneficial for those who already feel a strong sense of connectedness to the natural environment
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