1,398 research outputs found
Bourdieu, Strategy, and Identity Work: A Case from a Manufacturing Organisation in Sri Lanka
This empirical study aims to discuss how organisational actors' identity work is reflected through their strategy work, from a Bourdieusian perspective. The study is a case study which followed the qualitative research approach. The participants of the study were managers representing a cross-section of a manufacturing organisation in Sri Lanka. Twenty-six semi-structured interviews were used for the generation of the data for thematic analysis. NVivo12 data management software was used for the data management and in initial coding. It was found that managers are engaged in different identity work for self during their strategy work, in the implementation of a new organisational strategy. Further, the behaviour and practices normalised in the selected organisation through managers' strategy work reflected their identity work for other/s in way of defining other/s. The discussion was based on the theory of practice by Pierre Bourdieu (1990). Accordingly, this research shows how the identity work of position takers (newly joined and promoted organisational actors) supports shaping the practices linked with a new strategy (strategy work). Further, their identity work reflected through strategy work is also connected with their individual dispositions (habitus). The discussion further shows how individuals’ capital—mainly their cultural capital—contribute to constructing a new strategy in the selected organisational field. As implications of this study, it highlighted the contribution of the position-takers in shaping the organisation's strategy (strategy work) while engaging in identity work for self and others. Consequently, this study illustrates how organisational actors perform different social-symbolic work (identity work and strategy work) in parallel.
Keywords: Capital; Habitus, Identity work; Social-symbolic work; Strategy wor
Bayesian Analysis of Inflation III: Slow Roll Reconstruction Using Model Selection
We implement Slow Roll Reconstruction -- an optimal solution to the inverse
problem for inflationary cosmology -- within ModeCode, a publicly available
solver for the inflationary dynamics. We obtain up-to-date constraints on the
reconstructed inflationary potential, derived from the WMAP 7-year dataset and
South Pole Telescope observations, combined with large scale structure data
derived from SDSS Data Release 7. Using ModeCode in conjunction with the
MultiNest sampler, we compute Bayesian evidence for the reconstructed potential
at each order in the truncated slow roll hierarchy. We find that the data are
well-described by the first two slow roll parameters, \epsilon and \eta, and
that there is no need to include a nontrivial \xi parameter.Comment: 14 pages, 12 figures, minor changes; final version; accepted in PR
Classification of Multiwavelength Transients with Machine Learning
With the advent of powerful telescopes such as the Square Kilometer Array and
the Vera C. Rubin Observatory, we are entering an era of multiwavelength
transient astronomy that will lead to a dramatic increase in data volume.
Machine learning techniques are well suited to address this data challenge and
rapidly classify newly detected transients. We present a multiwavelength
classification algorithm consisting of three steps: (1) interpolation and
augmentation of the data using Gaussian processes; (2) feature extraction using
wavelets; and (3) classification with random forests. Augmentation provides
improved performance at test time by balancing the classes and adding diversity
into the training set. In the first application of machine learning to the
classification of real radio transient data, we apply our technique to the
Green Bank Interferometer and other radio light curves. We find we are able to
accurately classify most of the 11 classes of radio variables and transients
after just eight hours of observations, achieving an overall test accuracy of
78 percent. We fully investigate the impact of the small sample size of 82
publicly available light curves and use data augmentation techniques to
mitigate the effect. We also show that on a significantly larger simulated
representative training set that the algorithm achieves an overall accuracy of
97 percent, illustrating that the method is likely to provide excellent
performance on future surveys. Finally, we demonstrate the effectiveness of
simultaneous multiwavelength observations by showing how incorporating just one
optical data point into the analysis improves the accuracy of the worst
performing class by 19 percent.Comment: 16 pages, 12 figure
Quantifying the Rarity of the Local Super-Volume
We investigate the extent to which the number of clusters of mass exceeding 1015M⊙h−1 within the local super-volume (<135Mpch−1) is compatible with the standard ΛCDM cosmological model. Depending on the mass estimator used, we find that the observed number N of such massive structures can vary between 0 and 5. Adopting N = 5 yields ΛCDM likelihoods as low as 2.4 × 10−3 (with σ8 = 0.81) or 3.8 × 10−5 (with σ8 = 0.74). However, at the other extreme (N = 0), the likelihood is of order unity. Thus, while potentially very powerful, this method is currently limited by systematic uncertainties in cluster mass estimates. This motivates efforts to reduce these systematics with additional observations and improved modelling
Quantifying the Rarity of the Local Super-Volume
We investigate the extent to which the number of clusters of mass exceeding 1015M⊙h−1 within the local super-volume (<135Mpch−1) is compatible with the standard ΛCDM cosmological model. Depending on the mass estimator used, we find that the observed number N of such massive structures can vary between 0 and 5. Adopting N = 5 yields ΛCDM likelihoods as low as 2.4 × 10−3 (with σ8 = 0.81) or 3.8 × 10−5 (with σ8 = 0.74). However, at the other extreme (N = 0), the likelihood is of order unity. Thus, while potentially very powerful, this method is currently limited by systematic uncertainties in cluster mass estimates. This motivates efforts to reduce these systematics with additional observations and improved modelling
Cosmological Constraints on Dissipative Models of Inflation
(Abridged) We study dissipative inflation in the regime where the dissipative
term takes a specific form, \Gamma=\Gamma(\phi), analyzing two models in the
weak and strong dissipative regimes with a SUSY breaking potential. After
developing intuition about the predictions from these models through analytic
approximations, we compute the predicted cosmological observables through full
numerical evolution of the equations of motion, relating the mass scale and
scale of dissipation to the characteristic amplitude and shape of the
primordial power spectrum. We then use Markov Chain Monte Carlo techniques to
constrain a subset of the models with cosmological data from the cosmic
microwave background (WMAP three-year data) and large scale structure (SDSS
Luminous Red Galaxy power spectrum). We find that the posterior distributions
of the dissipative parameters are highly non-Gaussian and their allowed ranges
agree well with the expectations obtained using analytic approximations. In the
weak regime, only the mass scale is tightly constrained; conversely, in the
strong regime, only the dissipative coefficient is tightly constrained. A lower
limit is seen on the inflation scale: a sub-Planckian inflaton is disfavoured
by the data. In both weak and strong regimes, we reconstruct the limits on the
primordial power spectrum and show that these models prefer a {\it red}
spectrum, with no significant running of the index. We calculate the reheat
temperature and show that the gravitino problem can be overcome with large
dissipation, which in turn leads to large levels of non-Gaussianity: if
dissipative inflation is to evade the gravitino problem, the predicted level of
non-Gaussianity might be seen by the Planck satellite.Comment: 14 pages, 9 figures, Accepted by JCAP without text changes,
References adde
Comparing Infrared Dirac-Born-Infeld Brane Inflation to Observations
We compare the Infrared Dirac-Born-Infeld (IR DBI) brane inflation model to
observations using a Bayesian analysis. The current data cannot distinguish it
from the \LambdaCDM model, but is able to give interesting constraints on
various microscopic parameters including the mass of the brane moduli
potential, the fundamental string scale, the charge or warp factor of throats,
and the number of the mobile branes. We quantify some distinctive testable
predictions with stringy signatures, such as the large non-Gaussianity, and the
large, but regional, running of the spectral index. These results illustrate
how we may be able to probe aspects of string theory using cosmological
observations.Comment: 54 pages, 13 figures. v2: non-Gaussianity constraint has been applied
to the model; parameter constraints have tightened significantly, conclusions
unchanged. References added; v3, minor revision, PRD versio
First Observational Tests of Eternal Inflation: Analysis Methods and WMAP 7-Year Results
In the picture of eternal inflation, our observable universe resides inside a
single bubble nucleated from an inflating false vacuum. Many of the theories
giving rise to eternal inflation predict that we have causal access to
collisions with other bubble universes, providing an opportunity to confront
these theories with observation. We present the results from the first
observational search for the effects of bubble collisions, using cosmic
microwave background data from the WMAP satellite. Our search targets a generic
set of properties associated with a bubble collision spacetime, which we
describe in detail. We use a modular algorithm that is designed to avoid a
posteriori selection effects, automatically picking out the most promising
signals, performing a search for causal boundaries, and conducting a full
Bayesian parameter estimation and model selection analysis. We outline each
component of this algorithm, describing its response to simulated CMB skies
with and without bubble collisions. Comparing the results for simulated bubble
collisions to the results from an analysis of the WMAP 7-year data, we rule out
bubble collisions over a range of parameter space. Our model selection results
based on WMAP 7-year data do not warrant augmenting LCDM with bubble
collisions. Data from the Planck satellite can be used to more definitively
test the bubble collision hypothesis.Comment: Companion to arXiv:1012.1995. 41 pages, 23 figures. v2: replaced with
version accepted by PRD. Significant extensions to the Bayesian pipeline to
do the full-sky non-Gaussian source detection problem (previously restricted
to patches). Note that this has changed the normalization of evidence values
reported previously, as full-sky priors are now employed, but the conclusions
remain unchange
New Solutions of the Inflationary Flow Equations
The inflationary flow equations are a frequently used method of surveying the
space of inflationary models. In these applications the infinite hierarchy of
differential equations is truncated in a way which has been shown to be
equivalent to restricting the set of models considered to those characterized
by polynomial inflaton potentials. This paper explores a different method of
solving the flow equations, which does not truncate the hierarchy and in
consequence covers a much wider class of models while retaining the practical
usability of the standard approach.Comment: References added, and a couple of comment
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