370 research outputs found

    Diagnosing performance management and performance budgeting systems: A case study of the U.S. Navy

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    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

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    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

    Get PDF
    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

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    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

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    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

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    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 1041<LX<1044 erg s−110^{41} < L_{\rm X} < 10^{44}\,{\rm erg\,s}^{-1}, 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 243−-49 HLX−-1 and M82 X−-1. From a statistical study, we conservatively estimate that up to 71±1171 \pm 11 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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