15,558 research outputs found
The Effect of Interviewer Experience, Attitudes, Personality and Skills on Respondent Co-operation with Face-to-Face Surveys
This paper examines the role of interviewers' experience, attitudes, personality traits and inter-personal skills in determining survey co-operation, conditional on contact. We take the perspective that these characteristics influence interviewers' behaviour and hence influence the doorstep interaction between interviewer and sample member. Previous studies of the association between doorstep behaviour and co-operation have not directly addressed the role of personality traits and inter-personal skills and most have been based on small samples of interviewers. We use a large sample of 842 face-to-face interviewers working for a major survey institute and analyse co-operation outcomes for over 100,000 cases contacted by those interviewers over a 13-month period. We find evidence of effects of experience, attitudes, personality traits and inter-personal skills on co-operation rates. Several of the effects of attitudes and inter-personal skills are explained by differences in experience, though some independent effects remain. The role of attitudes, personality and skills seems to be greatest for the least experienced interviewers
I-V curves and intergranular flux creep activation energy in the magnetic superconductor RuSr2GdCu2O8
A systematic study of I-V characteristic curves for RuSr2GdCu2O8 [Ru-(1212)]
is presented, with magnetic fields up to 3 T and 5 K<T<30 K, in the region of
the superconducting transition. The activation energy E_{a}(H,T) for flux line
depinning was determined by fitting the nonlinear region of the curves using
the flux creep model. E_{a}(H,T) was found to vary linearly with temperature,
while a power-law dependence on the magnetic field was observed up to H=0.1 T,
where an abrupt reduction in its decreasing rate occurs. The extrapolated
value, E_{a}(0,0)=50 meV, is twice the reported value for YBa2Cu3O7, but the
critical current density J_{C}(0,0)=70 A/cm2 is about one order of magnitude
lower. These results are explained as a consequence of the contribution of the
magnetization in the grains to the effective field at the intergranular links
and to a spin-flop transition of the Ru-sub-lattice.Comment: 4 pages, 3 figure
First-order nature of the ferromagnetic phase transition in (La-Ca)MnO_3 near optimal doping
Neutron scattering has been used to study the nature of the ferromagnetic
transition in single crystals of La_0.7Ca_0.3MnO_3 and La_0.8Ca_0.2MnO_3, and
polycrystalline samples of La_0.67Ca_0.33MnO_3 and La_5/8Ca_3/8MnO_3 where the
naturally occurring O-16 can be replaced with the O-18 isotope. Small angle
neutron scattering on the x=0.3 single crystal reveals a discontinuous change
in the scattering at the Curie temperature for wave vectors below ~0.065 A^-1.
Strong relaxation effects are observed for this domain scattering, for the
magnetic order parameter, and for the quasielastic scattering, demonstrating
that the transition is not continuous in nature. There is a large oxygen
isotope effect observed for the T_C in the polycrystalline samples. For the
optimally doped x=3/8 sample we observed T_C(O-16)=266.5 K and T_C(O-18)=261.5
K at 90% O-18 substitution. The temperature dependence of the spin-wave
stiffness is found to be identical for the two samples despite changes in T_C.
Hence, T_C is not solely determined by the magnetic subsystem, but instead the
ferromagnetic phase is truncated by the formation of polarons which cause an
abrupt transition to the paramagnetic, insulating state. Application of
uniaxial stress in the x=0.3 single crystal sharply enhances the polaron
scattering at room temperature. Measurements of the phonon density-of-states
show only modest differences above and below T_C and between the two different
isotopic samples.Comment: 13 pages, 16 figures, submitted to Phys. Rev.
Real-Time Cavity QED with Single Atoms
The combination of cold atoms and large coherent coupling enables investigations in a new regime in cavity QED with single-atom trajectories monitored in real time with high signal-to-noise ratio. The underlying “vacuum-Rabi” splitting is clearly reflected in the frequency dependence of atomic transit signals recorded atom by atom, with evidence for mechanical light forces for intracavity photon number <1. The nonlinear optical response of one atom in a cavity is observed to be in accord with the one-atom quantum theory but at variance with semiclassical predictions
The game jam movement:disruption, performance and artwork
This paper explores the current conventions and intentions of the game jam - contemporary events that encourage the rapid, collaborative creation of game design prototypes. Game jams are often renowned for their capacity to encourage creativity and the development of alternative, innovative game designs. However, there is a growing necessity for game jams to continue to challenge traditional development practices through evolving new formats and perspectives to maintain the game jam as a disruptive, refreshing aspect of game development culture. As in other creative jam style events, a game jam is not only a process but also, an outcome. Through a discussion of the literature this paper establishes a theoretical basis with which to analyse game jams as disruptive, performative processes that result in original creative artefacts. In support of this, case study analysis of Development Cultures: a series of workshops that centred on innovation and new forms of practice through play, chance, and experimentation, is presented. The findings indicate that game jams can be considered as processes that inspire creativity within a community and that the resulting performances can be considered as a form of creative artefact, thus parallels can be drawn between game jams and performative and interactive art
A model for projectile fragmentation
A model for projectile fragmentation is developed whose origin can be traced
back to the Bevalac era. The model positions itself between the
phenomenological EPAX parametrization and transport models like "Heavy Ion
Phase Space Exploration" (HIPSE) model and antisymmetrised molecular dynamics
(AMD) model. A very simple impact parameter dependence of input temperature is
incorporated in the model which helps to analyze the more peripheral
collisions. The model is applied to calculate the charge, isotopic
distributions, average number of intermediate mass fragments and the average
size of largest cluster at different Z_{bound} of different projectile
fragmentation reactions at different energies.Comment: Talk given by Gargi Chaudhuri at the 11th International Conference on
Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA, May 27-June 1,
2012. 10 pages, 7 figure
Uncorrelated and correlated nanoscale lattice distortions in the paramagnetic phase of magnetoresistive manganites
Neutron scattering measurements on a magnetoresistive manganite
La(CaSr)MnO show that uncorrelated
dynamic polaronic lattice distortions are present in both the orthorhombic (O)
and rhombohedral (R) paramagnetic phases. The uncorrelated distortions do not
exhibit any significant anomaly at the O-to-R transition. Thus, both the
paramagnetic phases are inhomogeneous on the nanometer scale, as confirmed
further by strong damping of the acoustic phonons and by the anomalous
Debye-Waller factors in these phases. In contrast, recent x-ray measurements
and our neutron data show that polaronic correlations are present only in the O
phase. In optimally doped manganites, the R phase is metallic, while the O
paramagnetic state is insulating (or semiconducting). These measurements
therefore strongly suggest that the {\it correlated} lattice distortions are
primarily responsible for the insulating character of the paramagnetic state in
magnetoresistive manganites.Comment: 10 pages, 8 figures embedde
Quantum Monte Carlo Calculations of Light Nuclei Using Chiral Potentials
We present the first Green's function Monte Carlo calculations of light
nuclei with nuclear interactions derived from chiral effective field theory up
to next-to-next-to-leading order. Up to this order, the interactions can be
constructed in a local form and are therefore amenable to quantum Monte Carlo
calculations. We demonstrate a systematic improvement with each order for the
binding energies of and systems. We also carry out the first
few-body tests to study perturbative expansions of chiral potentials at
different orders, finding that higher-order corrections are more perturbative
for softer interactions. Our results confirm the necessity of a three-body
force for correct reproduction of experimental binding energies and radii, and
pave the way for studying few- and many-nucleon systems using quantum Monte
Carlo methods with chiral interactions.Comment: 5 pages, 3 figures, 4 tables. Updated references. Cosmetic changes to
figures, tables, and equations; added a sentence clarifying the
correspondence between our real-space cutoffs and momentum-space cutoffs.
Other sentences were reworded for clarit
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