4,372 research outputs found
Programmed schedule holds for improving launch vehicle holds
Baseline definition and system optimization are used for the analysis of programmed holds developed through prelaunch system analysis. Identification of design specifications for ground support equipment and maintenance concepts, and design specifications are used to describe the functional utilization of the overall flow process
Finite-Time Singularity Signature of Hyperinflation
We present a novel analysis extending the recent work of Mizuno et al. [2002]
on the hyperinflations of Germany (1920/1/1-1923/11/1), Hungary
(1945/4/30-1946/7/15), Brazil (1969-1994), Israel (1969-1985), Nicaragua
(1969-1991), Peru (1969-1990) and Bolivia (1969-1985). On the basis of a
generalization of Cagan's model of inflation based on the mechanism of
``inflationary expectation'' or positive feedbacks between realized growth rate
and people's expected growth rate, we find that hyperinflations can be
characterized by a power law singularity culminating at a critical time .
Mizuno et al.'s double-exponential function can be seen as a discrete time-step
approximation of our more general nonlinear ODE formulation of the price
dynamics which exhibits a finite-time singular behavior. This extension of
Cagan's model, which makes natural the appearance of a critical time , has
the advantage of providing a well-defined end of the clearly unsustainable
hyperinflation regime. We find an excellent and reliable agreement between
theory and data for Germany, Hungary, Peru and Bolivia. For Brazil, Israel and
Nicaragua, the super-exponential growth seems to be already contaminated
significantly by the existence of a cross-over to a stationary regime.Comment: Latex 21 pages including 2 tables and 7 eps figure
International Public Health Research Involving Interpreters: a Case Study from Bangladesh
Background: Cross-cultural and international research are important components of public health research, but the challenges of language barriers and working with interpreters are often overlooked, particularly in the case of qualitative research.
Methods: A case-study approach was used to explore experiences of working with an interpreter in Bangladesh as part of a research project investigating women's experiences of emergency obstetric care.
The case study: Data from the researcher's field notes provided evidence of experiences in working with an interpreter and show how the model of interviewing was adapted over time to give a more active role to the interpreter. The advantages of a more active role were increased rapport and "flow" in interviews. The disadvantages included reduced control from the researcher's perspective. Some tensions between the researcher and interpreter remained hard to overcome,
irrespective of the model used. Independent transcription and translation of the interviews also raised questions around accuracy in translation.
Conclusion: The issues examined in this case study have broader implications for public health research. Further work is needed in three areas: 1) developing effective relationships with interpreters; 2) the impact of the interpreter on the research process; and 3) the accuracy of the translation and level of analysis needed in any specific public health research. Finally, this paper highlights the importance to authors of reflecting on the potential impact of translation and interpretation on the research process when disseminating their research
The processing of number scales beyond whole numbers in development: Dissociations in arithmetic in Turner’s syndrome
The arithmetical skills in two children with Turner’s syndrome (TS), each the focus of a case study, were analysed in whole numbers and other number scales that have not been systematically explored previously, fractions, decimals, percentages, and negative numbers. The intention was to identify the fractionation of arithmetical skills. The two girls with TS showed dissociations of arithmetical skill in the calculation system of whole numbers that support its modular organization. Fractionation of skills was observed in some components of the other number scales, suggesting an analogous organization within these scales. The operational specificity of impairment within number scales but not others argued against a unitary arithmetical system but rather for autonomous operational scales within distinct number scales. A general model of arithmetic is proposed
WASP-189b: an ultra-hot Jupiter transiting the bright A star HR 5599 in a polar orbit
We report the discovery of WASP-189b: an ultra-hot Jupiter in a 2.72-d
transiting orbit around the A star WASP-189 (HR 5599). We detected
periodic dimmings in the star's lightcurve, first with the WASP-South survey
facility then with the TRAPPIST-South telescope. We confirmed that a planet is
the cause of those dimmings via line-profile tomography and radial-velocity
measurements using the HARPS and CORALIE spectrographs. Those reveal WASP-189b
to be an ultra-hot Jupiter ( = 2.13 0.28 ;
= 1.374 0.082 ) in a polar orbit (; ) around a rapidly rotating
A6IV-V star ( = 8000 100 K; 100
km\, s). We calculate a predicted equilibrium temperature of = 2641 34 K, assuming zero albedo and efficient redistribution,
which is the third hottest for the known exoplanets. WASP-189 is the brightest
known host of a transiting hot Jupiter and the third-brightest known host of
any transiting exoplanet. We note that of the eight hot-Jupiter systems with
7000 K, seven have strongly misaligned orbits, and two of the
three systems with 8000 K have polar orbits (the third is
aligned).Comment: Submitted to MNRAS. 10 pages, 9 figures, 3 table
A low-density hot Jupiter in a near-aligned, 4.5-day orbit around a = 10.8, F5V star
We report the independent discovery and characterisation of a hot Jupiter in
a 4.5-d, transiting orbit around the star TYC 7282-1298-1 ( = 10.8, F5V).
The planet has been pursued by the NGTS team as NGTS-2b and by ourselves as
WASP-179b. We characterised the system using a combination of photometry from
WASP-South and TRAPPIST-South, and spectra from CORALIE (around the orbit) and
HARPS (through the transit). We find the planet's orbit to be nearly aligned
with its star's spin. From a detection of the Rossiter-McLaughlin effect, we
measure a projected stellar obliquity of . From
line-profile tomography of the same spectra, we measure . We find the planet to have a low density ( = 0.67
0.09 , = 1.54 0.06 ), which, along
with its moderately bright host star, makes it a good target for transmission
spectroscopy. We find a lower stellar mass ( = )
than reported by the NGTS team ( = ), though the
difference is only .Comment: Submitted to AJ. 9 pages, 6 figures, 5 table
Ground State Energy of the Low Density Bose Gas
Now that the properties of low temperature Bose gases at low density, ,
can be examined experimentally it is appropriate to revisit some of the
formulas deduced by many authors 4-5 decades ago. One of these is that the
leading term in the energy/particle is , where is
the scattering length. Owing to the delicate and peculiar nature of bosonic
correlations, four decades of research have failed to establish this plausible
formula rigorously. The only known lower bound for the energy was found by
Dyson in 1957, but it was 14 times too small. The correct bound is proved here.Comment: 4 pages, Revtex, reference 12 change
Electoral and political changes: the impact on political bureaucratic relationships in Scottish Local Government
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