1,169 research outputs found
Design of Web Questionnaires: An Information Processing Perspective for the Effect of Response Categories
In this study we use an information-processing perspective to explore the impact of response scales on respondents answers in a web survey.This paper has four innovations compared to the existing literature: research is based on a different mode of administration (web), we use an open-ended format as a benchmark, four different question types are used, and the study is conducted on a representative sample of the population.We find strong effects of response scales.Questions requiring estimation strategies are more affected by the choice of response format than questions in which direct recall is used.Respondents with a low need for cognition and respondents with a low need to form opinions are more affected by the response categories than respondents with a high need for cognition and a high need to evaluate.The sensitivity to contextual clues is also significantly related to gender, age and educationweb survey;questionnaire design;measurement error;context effects;response categories;need for cognition;need to evaluate
Seamounts : characteristics, formation, mineral deposits and biodiversity
Seamounts represent crust-mantle activities and are areas of petrological deviations, biodiversity, seismicity and hydrothermal events. An estimated ~50 million tons/year of basalts are required to produce seamounts suggesting intense oceanic volcanism. Seamounts either occur as chains perpendicular to the ridge or as isolated entities or in clusters. Seamounts may host basalts, hyaloclastites, gabbros and serpentinites and these variants perhaps evolve from multiple melting domains as a consequence of large-scale thermal structure and mantle lithology. Nonhotspot seamounts on a young, thin and hot lithosphere host tholeiites whereas the plume related ones on thick, older lithosphere may be either tholeiitic or alkaline. Seamounts may bear hydrothermal deposits (Fe, Mn, Co) rare metals and phosphorites. The resistance of seamounts to subduction could trigger slides; while shearing of seamounts buried in subduction zones leads to seismicity, both of which could cause tsunamis. Seamounts greatly affect the circulation patterns and currents, which in turn influence the surrounding biota. We review here the seamounts in terms of discovery, characteristics, distribution and their influence on the marine environment
Design of Web Questionnaires:An Information Processing Perspective for the Effect of Response Categories
In this study we use an information-processing perspective to explore the impact of response scales on respondents answers in a web survey.This paper has four innovations compared to the existing literature: research is based on a different mode of administration (web), we use an open-ended format as a benchmark, four different question types are used, and the study is conducted on a representative sample of the population.We find strong effects of response scales.Questions requiring estimation strategies are more affected by the choice of response format than questions in which direct recall is used.Respondents with a low need for cognition and respondents with a low need to form opinions are more affected by the response categories than respondents with a high need for cognition and a high need to evaluate.The sensitivity to contextual clues is also significantly related to gender, age and education
An interacting scalar field and the recent cosmic acceleration
In this paper it is shown that the Brans - Dicke scalar field itself can
serve the purpose of providing an early deceleration and a late time
acceleration of the universe without any need of quintessence field if one
considers an interaction, i.e, transfer of energy between the dark matter and
the Brans - Dicke scalar field.Comment: 10 pages, 2 figure
New Realisations of Minimal Models and the Structure of W-Strings
The quantization of a free boson whose momentum satisfies a cubic constraint
leads to a c=\ha conformal field theory with a BRST symmetry. The theory also
has a symmetry in which all the generators except the stress-tensor
are BRST-exact and so topological. The BRST cohomology includes states of
conformal dimensions 0,\si,\ha, together with \lq copies' of these states
obtained by acting with picture-changing and screening operators. The 3-point
and 4-point correlation functions agree with those of the Ising model,
suggesting that the theory is equivalent to the critical Ising model. At tree
level, the string can be viewed as an ordinary string whose
conformal matter sector includes this realisation of the Ising model. The
two-boson string is equivalent to the Ising model coupled to
two-dimensional quantum gravity. Similar results apply for other W-strings and
minimal models.Comment: 28 pages, NSF-ITP-93-65, QMW-93-1
Load balanced and optimal disk allocation strategy for partial match queries on multidimensional files
A black hole hologram in de Sitter space
In this paper we show that the entropy of de Sitter space with a black hole
in arbitrary dimension can be understood using a modified Cardy-Verlinde
entropy formula. We also comment on the observer dependence of the de Sitter
entropy.Comment: 13 pages. Final version accepted for publication in JHEP. Added
references and improved presentatio
Solidification behavior of intensively sheared hypoeutectic Al-Si alloy liquid
The official published version of this article can be found at the link below.The effect of the processing temperature on the microstructural and mechanical properties of Al-Si (hypoeutectic) alloy solidified from intensively sheared liquid metal has been investigated systematically. Intensive shearing gives a significant refinement in grain size and intermetallic particle size. It also is observed that the morphology of intermetallics, defect bands, and microscopic defects in high-pressure die cast components are affected by intensive shearing the liquid metal. We attempt to discuss the possible mechanism for these effects.Funded by the EPSRC
The S-matrix of the Faddeev-Reshetikhin Model, Diagonalizability and PT Symmetry
We study the question of diagonalizability of the Hamiltonian for the
Faddeev-Reshetikhin (FR) model in the two particle sector. Although the two
particle S-matrix element for the FR model, which may be relevant for the
quantization of strings on , has been calculated recently
using field theoretic methods, we find that the Hamiltonian for the system in
this sector is not diagonalizable. We trace the difficulty to the fact that the
interaction term in the Hamiltonian violating Lorentz invariance leads to
discontinuity conditions (matching conditions) that cannot be satisfied. We
determine the most general quartic interaction Hamiltonian that can be
diagonalized. This includes the bosonic Thirring model as well as the bosonic
chiral Gross-Neveu model which we find share the same S-matrix. We explain this
by showing, through a Fierz transformation, that these two models are in fact
equivalent. In addition, we find a general quartic interaction Hamiltonian,
violating Lorentz invariance, that can be diagonalized with the same two
particle S-matrix element as calculated by Klose and Zarembo for the FR model.
This family of generalized interaction Hamiltonians is not Hermitian, but is
symmetric. We show that the wave functions for this system are also
symmetric. Thus, the theory is in a unbroken phase which guarantees the
reality of the energy spectrum as well as the unitarity of the S-matrix.Comment: 32 pages, 1 figure; references added, version published in JHE
Interacting Open Wilson Lines in Noncommutative Field Theories
In noncommutative field theories, it was known that one-loop effective action
describes propagation of non-interacting open Wilson lines, obeying the flying
dipole's relation. We show that two-loop effective action describes cubic
interaction among `closed string' states created by open Wilson lines. Taking
d-dimensional noncommutative [\Phi^3] theory as the simplest setup, we compute
nonplanar contribution at low-energy and large noncommutativity limit. We find
that the contribution is expressible in a remarkably simple cubic interaction
involving scalar open Wilson lines only and nothing else. We show that the
interaction is purely geometrical and noncommutative in nature, depending only
on sizes of each open Wilson line.Comment: v1: 27 pages, Latex, 7 .eps figures v2: minor wording change +
reference adde
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