1,536 research outputs found
Synapse: automatic behaviour inference and implementation comparison for Erlang
In the open environment of the world wide web, it is natural that there will be multiple providers of services, and that these service provisions â both specifications and implementations â will evolve. This multiplicity gives the user of these services a set of questions about how to choose between different providers, as well as how these choices work in an evolving environment.
The challenge, therefore, is to concisely represent to the user the behaviour of a particular implementation, and the differences between this implementation and alternative versions. Inferred models of software behaviour â and automatically derived and graphically presented comparisons between them â serve to support effective decision making in situations where there are competing implementations of requirements.
In this paper we use state machine models as the abstract representation of the behaviour of an implementation, and using these we build a tool by which one can visualise in an intuitive manner both the initial implementation and the differences between alternative versions. In this paper we describe our tool Synapse which implements this functionality by means of our grammar inference tool StateChum and a model-differencing algorithm. We describe the main functionality of Synapse, and demonstrate its usage by comparing different implementations of an example program from the existing literature
Systematic review of antimicrobial drug prescribing in hospitals.
Prudent antibiotic prescribing to hospital inpatients has the potential to reduce the incidences of antimicrobial resistance and healthcare-associated infection. We reviewed the literature from January 1980 to November 2003 to identify rigorous evaluations of interventions to improve hospital antibiotic prescribing. We identified 66 studies with interpretable data of which 16 reported 20 microbiological outcomes: Gram negative resistant bacteria (GNRB), 10 studies; Clostridium difficile associated diarrhoea (CDAD), 5 studies; vancomycin resistant enterococci (VRE), 3 studies and methicillin resistant Staphylococcus aureus (MRSA), 2 studies. Four studies provide good evidence that the intervention changed microbial outcomes with low risk of alternative explanations, eight studies provide less convincing evidence and four studies were negative. The strongest and most consistent evidence was for CDAD but we were able to analyse only the immediate impact of interventions because of nonstandardised durations of follow up. The ability to compare results of studies could be substantially improved by standardising methodology and reporting
The Hall of Mirrors Perceptions and Misperceptions in the Congressional Foreign Policy Process
Explores several factors related to an inconsistency in the voting record by the U.S. Congress on foreign policy issues, compared with the position taken by the public, administration officials, and leaders in business, labor, media, and education
XMM-Newton and optical follow-up observations of three new polars from the Sloan Digital Sky Survey
We report follow-up XMM-Newton and optical observations of three new polars
found in the Sloan Digital Sky Survey. Simple modeling of the X-ray spectra,
and consideration of the details of the X-ray and optical lightcurves
corroborate the polar nature of these three systems and provide further
insights into their accretion characteristics. During the XMM-Newton
observation of SDSS J072910.68+365838.3, X-rays are undetected apart from a
probable flare event, during which we find both the typical hard X-ray
bremsstrahlung component and a very strong line O VII (E=0.57 keV), but no
evidence of a soft blackbody contribution. In SDSS J075240.45+362823.2 we
identify an X-ray eclipse at the beginning of the observation, roughly in phase
with the primary minimum of the optical broad band curve. The X-ray spectra
require the presence of both hard and soft X-ray components, with their
luminosity ratio consistent with that found in other recent XMM-Newton results
on polars. Lastly, SDSS J170053.30+400357.6 appears optically as a very typical
polar, however its large amplitude optical modulation is 180 degrees out of
phase with the variation in our short X-ray lightcurve.Comment: 9 pages, 9 figures, accepted for publication in the ApJ (January
2005
Stochastic Functional Data Analysis: A Diffusion ModelâBased Approach
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/89505/1/j.1541-0420.2011.01591.x.pd
Consistency of functional learning methods based on derivatives
International audienceIn some real world applications, such as spectrometry, functional models achieve better predictive performances if they work on the derivatives of order m of their inputs rather than on the original functions. As a consequence, the use of derivatives is a common practice in Functional Data Analysis, despite a lack of theoretical guarantees on the asymptotically achievable performances of a derivative based model. In this paper, we show that a smoothing spline approach can be used to preprocess multivariate observations obtained by sampling functions on a discrete and finite sampling grid in a way that leads to a consistent scheme on the original infinite dimensional functional problem. This work extends (Mas and Pumo, 2009) to nonparametric approaches and incomplete knowledge. To be more precise, the paper tackles two difficulties in a nonparametric framework: the information loss due to the use of the derivatives instead of the original functions and the information loss due to the fact that the functions are observed through a discrete sampling and are thus also unperfectly known: the use of a smoothing spline based approach solves these two problems. Finally, the proposed approach is tested on two real world datasets and the approach is experimentaly proven to be a good solution in the case of noisy functional predictors
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