3,242 research outputs found

    Strategic Management and HRM

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    [Excerpt] The purpose of this chapter is to discuss this intersection between Strategic Management and HRM, what we know, and future directions for SHRM research. We will begin by briefly discussing the concept of strategy and the popularization of the resource-based view (RBV) of the firm. Next we will address its role in creating the link between HRM and Strategic Management including key questions that the RBV has raised in relation to SHRM. We will then examine the current state of affairs in SHRM; the progress made, and key questions and concerns occupying the attention of SHRM researchers. Finally, we will conclude with our views on future directions for SHRM research

    Optimal Strategies for Sinusoidal Signal Detection

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    We derive and study optimal and nearly-optimal strategies for the detection of sinusoidal signals hidden in additive (Gaussian and non-Gaussian) noise. Such strategies are an essential part of algorithms for the detection of the gravitational Continuous Wave (CW) signals produced by pulsars. Optimal strategies are derived for the case where the signal phase is not known and the product of the signal frequency and the observation time is non-integral.Comment: 18 pages, REVTEX4, 7 figures, 2 table

    FINDCHIRP: an algorithm for detection of gravitational waves from inspiraling compact binaries

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    Matched-filter searches for gravitational waves from coalescing compact binaries by the LIGO Scientific Collaboration use the FINDCHIRP algorithm: an implementation of the optimal filter with innovations to account for unknown signal parameters and to improve performance on detector data that has nonstationary and non-Gaussian artifacts. We provide details on the FINDCHIRP algorithm as used in the search for subsolar mass binaries, binary neutron stars, neutron star-black hole binaries, and binary black holes.Comment: 19 pages, 1 figure, journal version with Creative Commons 4.0 open-access license adde

    Robust Weak-lensing Mass Calibration of Planck Galaxy Clusters

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    In light of the tension in cosmological constraints reported by the Planck team between their SZ-selected cluster counts and Cosmic Microwave Background (CMB) temperature anisotropies, we compare the Planck cluster mass estimates with robust, weak-lensing mass measurements from the Weighing the Giants (WtG) project. For the 22 clusters in common between the Planck cosmology sample and WtG, we find an overall mass ratio of \left = 0.688 \pm 0.072. Extending the sample to clusters not used in the Planck cosmology analysis yields a consistent value of <MPlanck/MWtG>=0.698±0.062\left< M_{Planck}/M_{\rm WtG} \right> = 0.698 \pm 0.062 from 38 clusters in common. Identifying the weak-lensing masses as proxies for the true cluster mass (on average), these ratios are ∼1.6σ\sim 1.6\sigma lower than the default mass bias of 0.8 assumed in the Planck cluster analysis. Adopting the WtG weak-lensing-based mass calibration would substantially reduce the tension found between the Planck cluster count cosmology results and those from CMB temperature anisotropies, thereby dispensing of the need for "new physics" such as uncomfortably large neutrino masses (in the context of the measured Planck temperature anisotropies and other data). We also find modest evidence (at 95 per cent confidence) for a mass dependence of the calibration ratio and discuss its potential origin in light of systematic uncertainties in the temperature calibration of the X-ray measurements used to calibrate the Planck cluster masses. Our results exemplify the critical role that robust absolute mass calibration plays in cluster cosmology, and the invaluable role of accurate weak-lensing mass measurements in this regard.Comment: 5 pages, 2 figure

    Texas and Southwestern Cattle Raisers Association Members\u27 Preferred Sources of Animal Health Information

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    The nation’s agriculture and food infrastructure is vulnerable to significant social disruption and economic loss from hazards. Biological hazards, such as animal disease epidemics, have resulted in millions of dollars of economic loss and the death of millions of livestock in the past, and it will happen again unless infrastructure stakeholders adopt proper preventative measures. From farm to plate, defense starts on the farm with producers. With the multitude of potential hazards, many factors influence livestock producers’ protective action decision process. A major factor in the decision to take a protective action is from where or from whom the threat information originates. By identifying preferred sources, perceived credible sources, and preferred formats of animal health information by producers, risk communicators can more effectively develop critical animal health warnings and messages to promote rapid detection of hazards. This study targeted 7,661 members of the Texas and Southwestern Cattle Raisers Association. An online questionnaire developed from previous research with similar populations allowed TSCRA members to respond to questions related to the objectives of this study. A representative sample of TSCRA members from Texas, Oklahoma, and New Mexico responded and identified high levels of perceived trust and reliability in local veterinarians as a source of information along with livestock associations and county extension offices. TSCRA members also indicated they have multiple preferred formats for receiving animal health information. By using this information when communicating possible hazards, protective action from such threats will become more probable in this population

    Screening properties of Gaussian electrolyte models, with application to dissipative particle dynamics

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    We investigate the screening properties of Gaussian charge models of electrolyte solutions by analysing the asymptotic behaviour of the pair distribution functions. We use a combination of Monte-Carlo simulations with the hyper-netted chain integral equation closure, and the random phase approximation, to establish the conditions under which a screening length is well defined and the extent to which it matches the expected Debye length. For practical applications, for example in dissipative particle dynamics, we are able to summarise our results in succinct rules-of-thumb which can be used for mesoscale modeling of electrolyte solutions. We thereby establish a solid foundation for future work, such as the systematic incorporation of specific ion effects.Comment: 9 pages, 9 figures, 1 table, RevTeX4-

    Cosmology and Astrophysics from Relaxed Galaxy Clusters II: Cosmological Constraints

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    We present cosmological constraints from measurements of the gas mass fraction, fgasf_{gas}, for massive, dynamically relaxed galaxy clusters. Our data set consists of Chandra observations of 40 such clusters, identified in a comprehensive search of the Chandra archive, as well as high-quality weak gravitational lensing data for a subset of these clusters. Incorporating a robust gravitational lensing calibration of the X-ray mass estimates, and restricting our measurements to the most self-similar and accurately measured regions of clusters, significantly reduces systematic uncertainties compared to previous work. Our data for the first time constrain the intrinsic scatter in fgasf_{gas}, (7.4±2.3)(7.4\pm2.3)% in a spherical shell at radii 0.8-1.2 r2500r_{2500}, consistent with the expected variation in gas depletion and non-thermal pressure for relaxed clusters. From the lowest-redshift data in our sample we obtain a constraint on a combination of the Hubble parameter and cosmic baryon fraction, h3/2Ωb/Ωm=0.089±0.012h^{3/2}\Omega_b/\Omega_m=0.089\pm0.012, that is insensitive to the nature of dark energy. Combined with standard priors on hh and Ωbh2\Omega_b h^2, this provides a tight constraint on the cosmic matter density, Ωm=0.27±0.04\Omega_m=0.27\pm0.04, which is similarly insensitive to dark energy. Using the entire cluster sample, extending to z>1z>1, we obtain consistent results for Ωm\Omega_m and interesting constraints on dark energy: ΩΛ=0.65−0.22+0.17\Omega_\Lambda=0.65^{+0.17}_{-0.22} for non-flat Λ\LambdaCDM models, and w=−0.98±0.26w=-0.98\pm0.26 for flat constant-ww models. Our results are both competitive and consistent with those from recent CMB, SNIa and BAO data. We present constraints on models of evolving dark energy from the combination of fgasf_{gas} data with these external data sets, and comment on the possibilities for improved fgasf_{gas} constraints using current and next-generation X-ray observatories and lensing data. (Abridged)Comment: 25 pages, 14 figures, 8 tables. Accepted by MNRAS. Code and data can be downloaded from http://www.slac.stanford.edu/~amantz/work/fgas14/ . v2: minor fix to table 1, updated bibliograph
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