1,129 research outputs found
Exploring âeventsâ as an information systems research methodology
This paper builds upon existing research and commentary from a variety of disciplinary sources including Information Systems, Organisational and Management Studies, and the Social Sciences that focus upon the meaning, significance and impact of âeventsâ in both an
organisational and a social sense. The aim of this paper is to define how the examination of the event is an appropriate, viable and useful Information Systems methodology. Our argument is that focusing on the âeventâ enables the researcher to more clearly observe and capture the complexity, multiplicity and mundaneity of everyday lived experience. The use and notion of âeventâ has the potential to reduce the methodological dilemmas associated
with the micromanagement of the research process â an inherent danger of traditional and âvirtual' ethnographic approaches. Similarly, this paper addresses the over-emphasis upon managerialist, structured and time-fixated praxis that is currently symptomatic of Information Systems research. All of these concerns are pivotal points of critique found within eventoriented literature. An examination of event-related theory within interpretative disciplines directs the focus of this paper towards the more specific realm of the âevent sceneâ. The notion of the âevent sceneâ originated in the action based (and anti-academy) imperatives of the Situationists and emerged in an academic sense as critical situational analysis. Event scenes are a focus for contemporary critical theory where they are utilised as a means of representing theoried
inquiry in order to loosen the restrictions that historical and temporally bound analysis imposes upon most interpretative approaches. The use of event scenes as the framework for critiquing established conceptual assumptions is exemplified by their use in CTheory. In this
journal's version and articulation of the event scene poetry, commentary, multi-vocal narrative and other techniques are legitimated as academic forms. These various forms of multi-dimensional expression are drawn upon to enrich the understandings of the âeventâ, to
extricate its meaning and to provide a sense of the moment from which the point of analysis stems. The objective of this paper is to advocate how Information Systems research can (or should) utilize an event scene oriented methodology
Pulse Profiles, Accretion Column Dips and a Flare in GX 1+4 During a Faint State
The Rossi X-ray Timing Explorer (RXTE) spacecraft observed the X-ray pulsar
GX 1+4 for a period of 34 hours on July 19/20 1996. The source faded from an
intensity of ~20 mCrab to a minimum of <~0.7 mCrab and then partially recovered
towards the end of the observation. This extended minimum lasted ~40,000
seconds. Phase folded light curves at a barycentric rotation period of
124.36568 +/- 0.00020 seconds show that near the center of the extended minimum
the source stopped pulsing in the traditional sense but retained a weak dip
feature at the rotation period. Away from the extended minimum the dips are
progressively narrower at higher energies and may be interpreted as
obscurations or eclipses of the hot spot by the accretion column. The pulse
profile changed from leading-edge bright before the extended minimum to
trailing-edge bright after it. Data from the Burst and Transient Source
Experiment (BATSE) show that a torque reversal occurred <10 days after our
observation. Our data indicate that the observed rotation departs from a
constant period with a Pdot/P value of ~-1.5% per year at a 4.5 sigma
significance. We infer that we may have serendipitously obtained data, with
high sensitivity and temporal resolution about the time of an accretion disk
spin reversal. We also observed a rapid flare which had some precursor
activity, close to the center of the extended minimum.Comment: 19 pages, 6 figures, accepted for publication in Astrophysical
Journal (tentatively scheduled for vol. 529 #1, 20 Jan 2000
The optical counterpart of SAX J1808.4-3658, the transient bursting millisecond X-ray pulsar
A set of CCD images have been obtained during the decline of the X-ray
transient SAX J1808.4-3658 during April-June 1998. The optical counterpart has
been confirmed by several pieces of evidence. The optical flux shows a
modulation on several nights which is consistent with the established X-ray
binary orbit period of 2 hours. This optical variability is roughly in
antiphase with the weak X-ray modulation. The source mean magnitude of V=16.7
on April 18 declined rapidly after April 22. From May 2 onwards the magnitude
was more constant at around V=18.45 but by June 27 was below our sensitivity
limit. The optical decline precedes the rapid second phase of the X-ray
decrease by 3 +/- 1 days. The source has been identified on a 1974 UK Schmidt
plate at an estimated magnitude of ~20. The nature of the optical companion is
discussed.Comment: 5 pages, 3 figures; published in MNRAS, March 15th 199
Accretion column eclipses in the X-ray pulsars GX 1+4 and RX J0812.4-3114
Sharp dips observed in the pulse profiles of three X-ray pulsars (GX 1+4, RX
J0812.4-3114 and A 0535+26) have previously been suggested to arise from
partial eclipses of the emission region by the accretion column occurring once
each rotation period. We present pulse-phase spectroscopy from Rossi X-ray
Timing Explorer satellite observations of GX 1+4 and RX J0812.4-3114 which for
the first time confirms this interpretation. The dip phase corresponds to the
closest approach of the column axis to the line of sight, and the additional
optical depth for photons escaping from the column in this direction gives rise
to both the decrease in flux and increase in the fitted optical depth measured
at this phase. Analysis of the arrival time of individual dips in GX~1+4
provides the first measurement of azimuthal wandering of a neutron star
accretion column. The column longitude varies stochastically with standard
deviation 2-6 degrees depending on the source luminosity. Measurements of the
phase width of the dip both from mean pulse profiles and individual eclipses
demonstrates that the dip width is proportional to the flux. The variation is
consistent with that expected if the azimuthal extent of the accretion column
depends only upon the Keplerian velocity at the inner disc radius, which varies
as a consequence of the accretion rate Mdot.Comment: 7 pages, 5 figures, accepted by MNRAS. Included reference
Spectral variation in the X-ray pulsar GX 1+4 during a low-flux episode
The X-ray pulsar GX 1+4 was observed with the RXTE satellite for a total of
51ks between 1996 July 19 - 21. During this period the flux decreased smoothly
from an initial mean level of ~ 6 X 10^36 erg/s to a minimum of ~ 4 X 10^35
erg/s (2-60 keV, assuming a source distance of 10 kpc) before partially
recovering towards the initial level at the end of the observation.
BATSE pulse timing measurements indicate that a torque reversal took place
approximately 10 d after this observation. Both the mean pulse profile and the
photon spectrum varied significantly. The observed variation in the source may
provide important clues as to the mechanism of torque reversals.
The single best-fitting spectral model was based on a component originating
from thermal photons with kT ~ 1 keV Comptonised by a plasma of temperature kT
\~ 7 keV. Both the flux modulation with phase during the brightest interval and
the evolution of the mean spectra over the course of the observation are
consistent with variations in this model component; with, in addition, a
doubling of the column density nH contributing to the mean spectral change.
A strong flare of duration 50 s was observed during the interval of minimum
flux, with the peak flux ~ 20 times the mean level. Although beaming effects
are likely to mask the true variation in Mdot thought to give rise to the
flare, the timing of a modest increase in flux prior to the flare is consistent
with dual episodes of accretion resulting from successive orbits of a locally
dense patch of matter in the accretion disc.Comment: 8 pages, 3 figures, submitted to MNRA
The Social Supply Chain and the Future High Street
Purpose: The paper examines how independent social and commercial activities have developed in response to the perceived decline in the UK High Street and in response to the challenges of increasing digital retailing opportunities. This examination is undertaken through the lens of the social supply chain as a means to understanding, suggesting and expanding on current research regarding retailing and the UK High Street. We reveal some of the challenges being posed by the changing patterns of growth and consumption in cities and couple these with shifting supply chain trends. Design: A case study approach is employed to explore the rapid advances and influence of digital technologies on businesses operating on the primary business street of suburban centre, towns or cities (described in the UK collectively as the âhigh streetâ). The study is conducted through the analytical lens of the social supply chain. Originality: For the purpose of this paper we use two distinct strategies relating to delivery and balancing and in relation to the actions of co-creation, co-production and co-consumption to emphasise and analyse changes currently occurring in the UK high street. We take a social supply chain management perspective to undertake a systematic critical review of the various recent efforts undertaken by local governments, communities and traders groups to revitalise the high street. Findings: Theoretically extending the âsocialâ in the social supply chain we illustrate the usefulness of the nuanced concept of the âsocial supply chainâ with two related strategies concerning delivery and balance. These strategies are themselves interlinked with the actions of co-creation, co-production and co-consumption. Examples of social supply chain strategies presented include retail businesses giving away something as an incentive, where the underlying requirement from the customer is that they will bring their own specialist product, skill or social network to a specified location (real or virtual)
From Prosumer to âProdesignerâ: Participatory News Consumption
New democratic participation forms and collaborative productions of diverse audiences have emerged as a result of digital innovations in the online access to and consumption of news. The aim of this paper is to propose a conceptual framework based on the possibilities of Web 2.0. Outlining the construction of a âsocial logicâ, which combines computer and communicative logics, the conceptual framework is theoretically built to explore the evolution of news consumption from a pure circulation of designed products towards a global conversation of proactive news designers. Then, the framework was tested using an empirical database built by the Pew Research Centre, which investigates the future of the news industry, through a large-scale survey with adults. Results show significant differences (by age, gender and educational level) in the forms of participation, access and consumption of news. However, whilst immersed in the culture of Web 2.0 there is a low-level of user participation in news production; far from being proactive news designers, findings suggest that citizens still located in the lower participatory levels of our conceptual framework. Conclusions suggest there is a need for media education providers to carry out training initiatives according to the social logic possibilities through proposed guidelines
21cm Absorption by Compact Hydrogen Disks Around Black Holes in Radio-Loud Nuclei of Galaxies
The clumpy maser disks observed in some galactic nuclei mark the outskirts of
the accretion disk that fuels the central black hole and provide a potential
site of nuclear star formation. Unfortunately, most of the gas in maser disks
is currently not being probed; large maser gains favor paths that are
characterized by a small velocity gradient and require rare edge-on
orientations of the disk. Here we propose a method for mapping the atomic
hydrogen distribution in nuclear disks through its 21cm absorption against the
radio continuum glow around the central black hole. In NGC 4258, the 21cm
optical depth may approach unity for high angular-resolution (VLBI) imaging of
coherent clumps which are dominated by thermal broadening and have the column
density inferred from X-ray absorption data, ~10^{23}/cm^2. Spreading the 21cm
absorption over the full rotation velocity width of the material in front of
the narrow radio jets gives a mean optical depth of ~0.1. Spectroscopic
searches for the 21cm absorption feature in other galaxies can be used to
identify the large population of inclined gaseous disks which are not masing in
our direction. Follow-up imaging of 21cm silhouettes of accelerating clumps
within these disks can in turn be used to measure cosmological distances.Comment: 4 page
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