370 research outputs found
Diagnosing performance management and performance budgeting systems: A case study of the U.S. Navy
We present here a case study of an organization within the U.S. Navy that created a new organizational construct and performance management system. We explore the issues faced by naval leaders as they attempt to use their performance information to make resource allocation decisions at the sub-organization level, and base budgets at the organization and service (navy) level. We attempt to diagnose many of the practical problems a government organization encounters when implementing a performance management system, to include trying to inform budgets, and make recommendations on actions that would improve the strength of the performance system. We find in the organization a good conceptual framework, organizational enthusiasm, and reasonable attempts to link disparate information systems into a coherent whole. The good intentions are hindered, however, by inadequate accounting systems, a lack of understanding of cost accounting methods, weak use of terminology and longstanding institutional attitudes. This case confirms challenges associated with both performance management systems and performance budgeting found in the literature, and we offer recommendations for public officials considering such endeavors
Strategy at the crossroads: The case of the navy hospital ships
We examine the state of knowledge in the defense literature on the use of military medical humanitarian assistance missions and examine their implications for navy hospital ships. As humanitarian assistance missions grow in importance for combatant commanders, deployed forces, senior government leaders and the international community, it becomes more important to determine desired outcomes and to set clear priorities for hospital ship use. Only when this is done can activities that promote achievement of policy goals be selected. While traditional hospital ship missions focus on combat support and training, successful humanitarian assistance campaigns typically address improving security and stability in a region, attitudes towards Americans and the West, and health and welfare conditions of local populations. We argue that well-crafted and communicated goals and priorities for the use of hospital ships are essential if the ships are to achieve desired policy outcomes.humanitarian assistance; military medicine; strategic planning
Diagnosing performance management and performance budgeting systems: A case study of the U.S. Navy
We present here a case study of an organization within the U.S. Navy that created a new organizational construct and performance management system. We explore the issues faced by naval leaders as they attempt to use their performance information to make resource allocation decisions at the sub-organization level, and base budgets at the organization and service (navy) level. We attempt to diagnose many of the practical problems a government organization encounters when implementing a performance management system, to include trying to inform budgets, and make recommendations on actions that would improve the strength of the performance system. We find in the organization a good conceptual framework, organizational enthusiasm, and reasonable attempts to link disparate information systems into a coherent whole. The good intentions are hindered, however, by inadequate accounting systems, a lack of understanding of cost accounting methods, weak use of terminology and longstanding institutional attitudes. This case confirms challenges associated with both performance management systems and performance budgeting found in the literature, and we offer recommendations for public officials considering such endeavors.performance management; performance budgeting; public budgeting
Investigating the mass of the intermediate mass black hole candidate HLX-1 with the SLIMBH model
In this paper we present a comprehensive study of the mass of the
intermediate mass black hole candidate HLX-1 in the galaxy ESO 243-49. We
analyse the continuum X-ray spectra collected by Swift, XMM-Newton, and Chandra
with the slim disc model, SLIMBH, and estimate the black hole mass for the full
range of inclination (inc = 0{\deg} - 85{\deg}) and spin (a* = 0 - 0.998). The
relativistic SLIMBH model is particularly suited to study high luminosity disc
spectra as it incorporates the effects of advection, such as the shift of the
inner disc edge towards smaller radii and the increasing height of the disc
photosphere (including relativistic ray-tracing from its proper location rather
than the mid-plane of the disc). We find for increasing values of inclination
that a zero spin black hole has a mass range of 6,300 - 50,900 M_sun and a
maximally spinning black hole has a mass between 16,900 - 191,700 M_sun. This
is consistent with previous estimates and reinforces the idea that HLX-1
contains an intermediate mass black hole.Comment: updated version, published in Astronomy and Astrophysic
Measurement of the Radius of Neutron Stars with High S/N Quiescent Low-mass X-ray Binaries in Globular Clusters
This paper presents the measurement of the neutron star (NS) radius using the
thermal spectra from quiescent low-mass X-ray binaries (qLMXBs) inside globular
clusters (GCs). Recent observations of NSs have presented evidence that cold
ultra dense matter -- present in the core of NSs -- is best described by
"normal matter" equations of state (EoSs). Such EoSs predict that the radii of
NSs, Rns, are quasi-constant (within measurement errors, of ~10%) for
astrophysically relevant masses (Mns > 0.5 Msun). The present work adopts this
theoretical prediction as an assumption, and uses it to constrain a single Rns
value from five qLMXB targets with available high signal-to-noise X-ray
spectroscopic data. Employing a Markov-Chain Monte-Carlo approach, we produce
the marginalized posterior distribution for Rns, constrained to be the same
value for all five NSs in the sample. An effort was made to include all
quantifiable sources of uncertainty into the uncertainty of the quoted radius
measurement. These include the uncertainties in the distances to the GCs, the
uncertainties due to the Galactic absorption in the direction of the GCs, and
the possibility of a hard power-law spectral component for count excesses at
high photon energy, which are observed in some qLMXBs in the Galactic plane.
Using conservative assumptions,we found that the radius, common to the five
qLMXBs and constant for a wide range of masses, lies in the low range of
possible NS radii, Rns=9.1(+1.3)(-1.5) km (90%-confidence). Such a value is
consistent with low-res equations of state. We compare this result with
previous radius measurements of NSs from various analyses of different types of
systems. In addition, we compare the spectral analyses of individual qLMXBs to
previous works.Comment: Accepted to Apj. 31 pages, 17 figures, 8 table
A search for hyperluminous X-ray sources in the XMM-Newton source catalog
We present a new method to identify luminous off-nuclear X-ray sources in the
outskirts of galaxies from large public redshift surveys, distinguishing them
from foreground and background interlopers. Using the 3XMM-DR5 catalog of X-ray
sources and the SDSS DR12 spectroscopic sample of galaxies, with the help of
this off-nuclear cross-matching technique, we selected 98 sources with inferred
X-ray luminosities in the range , compatible with hyperluminous X-ray objects (HLX). To validate
the method, we verify that it allowed us to recover known HLX candidates such
as ESO 24349 HLX1 and M82 X1. From a statistical study, we
conservatively estimate that up to of these sources may be fore- or
background sources, statistically leaving at least 16 that are likely to be
HLXs, thus providing support for the existence of the HLX population. We
identify two good HLX candidates and using other publicly available datasets,
in particular the VLA FIRST in radio, UKIDSS in the near-infrared, GALEX in the
ultra-violet and CFHT Megacam archive in the optical, we present evidence that
these objects are unlikely to be foreground or background X-ray objects of
conventional types, e.g. active galactic nuclei, BL Lac objects, Galactic X-ray
binaries or nearby stars. However, additional dedicated X-ray and optical
observations are needed to confirm their association with the assumed host
galaxies and thus secure their HLX classification.Comment: 20 pages, 6 figures, accepted to Ap
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