1,208 research outputs found
Situating organizational action: the relational sociology of organizations
This paper advances a relational sociology of organization that seeks to address concerns over how organizational action is understood and situated. The approach outlined here is one which takes ontology seriously and requires transparency and consistency of position. It aims at causal explanation over description and/or prediction and seeks to avoid pure voluntarism or structural determinism in such explanation. We advocate relational analysis that recognizes and engages with connections within and across organization and with wider contexts. We develop this argument by briefly reviewing three promising approaches: relational pragmatism, the social theorizing of Bourdieu and critical realism, highlighting their ontological foundations, some similarities and differences and surfacing some methodological issues. Our purpose is to encourage analysis that explores the connections within and between perspectives and theoretical positions. We conclude that the development of the field of organization theory will benefit from self conscious and reflexive engagement and debate both within and across our various research positions and traditions only if such debates are conducted on the basis of holistic evaluations and interpretations that recognize (and value) difference
Guide to the use of Mariner images
Planetary imaging from unmanned spacecraft, almost exclusively done by digital systems, is examined. The Mars Mariner 9 television camera, representative of such systems, is considered. Each image consists of 700 lines, each containing 832 picture elements, or pixels. Each pixel contains nine binary bits of information capable of displaying 512 discrete brightness levels. Several problems inherent in television systems are discussed. These include nonuniform target response, residual images, noise, and blemishes. These defects can be removed to some extent by decalibration of the image. The final product is geometrically corrected for camera distortion and photometrically corrected. Several versions of the decalibrated images are available. The most generally useful are the geometrically corrected images with enhanced contrast. The Mariner 10 imaging of Mercury is briefly discussed
The limits of process: On (re)reading Henri Bergson
This article offers a reading of the work of Henri Bergson as it pertains to organizations through the lens of ideas drawn from critical realism. It suggests an alternative to interpretations based on a stark division between process and realist perspectives. Much of the existing literature presents a rather partial view of Bergson’s work. A review suggests some interesting parallels with themes in critical realism, notably the emergence of mind. Critical realism has a focus on process at its heart, but is also concerned with how the products of such processes become stabilized and form the conditions for action. This suggests that attention might usefully be paid to the relationship between organizational action and the sedimented practices grouped under the heading of ‘routines’. More attention to Bergson’s account of the relationship between instinct, intuition and intelligence provides a link to the social character of thought, something which can be mapped on to Archer’s work on reflexivity and the ‘internal conversation’. This suggests that our analyses need to pay attention to both memory and history, to building and dwelling, rather than the one-sided focus found in some process theory accounts
Dark ages reionization & galaxy formation simulation XII: Bubbles at dawn
Direct detection of regions of ionized hydrogen (HII) has been suggested as a
promising probe of cosmic reionization. Observing the redshifted 21-cm signal
of hydrogen from the epoch of reionization (EoR) is a key scientific driver
behind new-generation, low-frequency radio interferometers. We investigate the
feasibility of combining low-frequency observations with the Square Kilometre
Array and near infra-red survey data of the Wide-Field Infrared Survey
Telescope to detect cosmic reionization by imaging HII bubbles surrounding
massive galaxies during the cosmic dawn. While individual bubbles will be too
small to be detected, we find that by stacking redshifted 21-cm spectra centred
on known galaxies, it will be possible to directly detect the EoR at , and to place qualitative constraints on the evolution of the spin
temperature of the intergalactic medium (IGM) at . In particular,
given a detection of ionized bubbles using this technique, it is possible to
determine if the IGM surrounding them is typically in absorption or emission.
Determining the globally-averaged neutral fraction of the IGM using this method
will prove more difficult due to degeneracy with the average size of HII
regions.Comment: 14 pages, 11 figures, 2 tables, published in MNRAS. Updated to match
published version. Additional results and comments added from previous
version. All other results and conclusions remain unchange
Dark-ages Reionization and Galaxy Formation Simulation - XIV. Gas accretion, cooling and star formation in dwarf galaxies at high redshift
We study dwarf galaxy formation at high redshift () using a suite of
high- resolution, cosmological hydrodynamic simulations and a semi-analytic
model (SAM). We focus on gas accretion, cooling and star formation in this work
by isolating the relevant process from reionization and supernova feedback,
which will be further discussed in a companion paper. We apply the SAM to halo
merger trees constructed from a collisionless N-body simulation sharing
identical initial conditions to the hydrodynamic suite, and calibrate the free
parameters against the stellar mass function predicted by the hydrodynamic
simulations at z = 5. By making comparisons of the star formation history and
gas components calculated by the two modelling techniques, we find that
semi-analytic prescriptions that are commonly adopted in the literature of
low-redshift galaxy formation do not accurately represent dwarf galaxy
properties in the hydrodynamic simulation at earlier times. We propose 3
modifications to SAMs that will provide more accurate high-redshift
simulations. These include 1) the halo mass and baryon fraction which are
overestimated by collisionless N-body simulations; 2) the star formation
efficiency which follows a different cosmic evolutionary path from the
hydrodynamic simulation; and 3) the cooling rate which is not well defined for
dwarf galaxies at high redshift. Accurate semi-analytic modelling of dwarf
galaxy formation informed by detailed hydrodynamical modelling will facilitate
reliable semi-analytic predictions over the large volumes needed for the study
of reionization.Comment: 20 pages, 10 figures; Updated to match the published version. All
results and conclusions remain unchange
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